Citation Nr: 21003522 Decision Date: 01/21/21 Archive Date: 01/21/21 DOCKET NO. 17-36 477 DATE: January 21, 2021 ORDER The previously denied claim of entitlement to service connection for a seizure disorder is reopened; to this limited extent, the appeal of that issue is granted. Service connection for hypertension is denied. Service connection for gangrene is denied. Service connection for hearing loss is denied. Service connection for tinnitus is denied. The prior 40 percent rating for diabetes mellitus, type II, is restored, effective December 1, 2015. An effective date no earlier than May 6, 2015 is granted for the award of service connection for diabetic peripheral neuropathy of the right lower extremity. An effective date no earlier than May 6, 2015 is granted for the award of service connection for diabetic peripheral neuropathy of the left lower extremity. A disability rating in excess of 10 percent for diabetic peripheral neuropathy of the right lower extremity is denied. A disability rating in excess of 10 percent for diabetic peripheral neuropathy of the left lower extremity is denied. A disability rating in excess of 40 percent for diabetes mellitus, type II, is denied. REMANDED Entitlement to service connection for a seizure disorder is remanded. Entitlement to a total disability rating based on individual unemployability due to service-connected disability (TDIU) is remanded. FINDINGS OF FACT 1. New evidence received since the time of a July 2012 decision denying service connection for a seizure disorder, when considered with the evidence previously of record, relates to an unestablished fact necessary to substantiate the claim. 2. The preponderance of the evidence is against a finding that the Veteran’s hypertension was shown as chronic in service or manifested to a compensable degree within the applicable presumptive period; continuity of symptomatology is not established and the disability is not otherwise shown to have been etiologically related to an in-service event, injury, or illness, to include as due to exposure to herbicide agents or as secondary to a service-connected disability. 3. The preponderance of the evidence is against a finding that the Veteran had a current diagnosis of gangrene, or residuals from a past incidence of gangrene, during the appeal period. 4. The preponderance of the evidence is against a finding that the Veteran’s hearing loss was shown as chronic in service or manifested to a compensable degree within the applicable presumptive period; continuity of symptomatology is not established and the disability is not otherwise shown to have been etiologically related to an in-service event, injury, or illness. 5. The preponderance of the evidence is against a finding that the Veteran’s tinnitus was shown as chronic in service or manifested to a compensable degree within the applicable presumptive period; continuity of symptomatology is not established and the disability is not otherwise shown to have been etiologically related to an in-service event, injury, or illness. 6. Resolving reasonable doubt in the appellant’s favor, improvement of the Veteran’s diabetes mellitus under the ordinary conditions of life and work was not demonstrated during the period after the issuance of an October 2014 rating decision proposing to decrease his disability rating for the condition. 7. The evidence of record indicates that the Veteran first expressed experiencing symptoms of diabetic peripheral neuropathy of the right lower extremity in a May 6, 2015 VA treatment record, during the pendency of his claim for an increased rating for diabetes. 8. The evidence of record indicates that the Veteran first expressed experiencing symptoms of diabetic peripheral neuropathy of the left lower extremity in a May 6, 2015 VA treatment record, during the pendency of his claim for an increased rating for diabetes. 9. The diabetic peripheral neuropathy of the Veteran’s right lower extremity most nearly approximated mild incomplete paralysis of the sciatic nerve during the period on appeal. 10. The diabetic peripheral neuropathy of the Veteran’s left lower extremity most nearly approximated mild incomplete paralysis of the sciatic nerve during the period on appeal. 11. The Veteran’s diabetes mellitus required one or more daily injections of insulin, restricted diet, and regulation of activities during the period on appeal; the condition was not manifested by episodes of ketoacidosis or hypoglycemic reactions requiring one or two hospitalizations per year or twice a month visits to a diabetic care provider. CONCLUSIONS OF LAW 1. New and material evidence has been received to reopen the claim for service connection for a seizure disorder. 38 U.S.C. § 5108; 38 C.F.R. § 3.156. 2. The criteria for an award of service connection for hypertension have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 3. The criteria for an award of service connection for gangrene have not been met. 38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303. 4. The criteria for an award of service connection for hearing loss have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 5. The criteria for an award of service connection for tinnitus have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. 6. The reduction of the Veteran’s rating for diabetes mellitus, type II, from 40 to 20 percent disabling, effective December 1, 2015, was improper. 38 U.S.C. §§ 1155, 5112; 38 C.F.R. §§ 3.105(e), 4.120, Diagnostic Code 7913. 7. The criteria for an effective date of May 6, 2015, but no earlier, for diabetic peripheral neuropathy of the right lower extremity have been met. 38 U.S.C. §§ 5101, 5103, 5107, 5110; 38 C.F.R. §§ 3.102, 3.114, 3.151, 3.155, 3.159, 3.400. 8. The criteria for an effective date of May 6, 2015, but no earlier, for diabetic peripheral neuropathy of the left lower extremity have been met. 38 U.S.C. §§ 5101, 5107, 5110; 38 C.F.R. §§ 3.102, 3.114, 3.151, 3.155, 3.400. 9. The criteria for a rating in excess of 10 percent for diabetic peripheral neuropathy of the right lower extremity have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.114, Diagnostic Code 8520. 10. The criteria for a rating in excess of 10 percent for diabetic peripheral neuropathy of the left lower extremity have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.7, 4.114, Diagnostic Code 8520. 11. The criteria for a rating in excess of 40 percent for diabetes have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 4.1, 4.3, 4.114, Diagnostic Code 7913. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty in the United States Army from March 1964 to March 1966, to include service in Vietnam. Unfortunately, he died in January 2020. The appellant is his surviving spouse, who has been substituted for the Veteran for purposes of prosecuting his claims to completion. 38 U.S.C. § 5121A. These matters come to the Board of Veterans’ Appeals (Board) on appeal from September 2015 and March 2016 rating decisions issued by a Department of Veterans Affairs (VA) Regional Office. The issues on appeal were previously before the Board in May 2018, when they were remanded to the agency of original jurisdiction (AOJ) for additional development. After taking further action, the AOJ confirmed and continued the prior denials and returned the case to the Board. In the May 2018 remand, the Board directed the AOJ to request the Veteran’s records from the Social Security Administration (SSA) pertaining to any award of disability benefits. The claims file reflects that the AOJ requested the records, but was informed by SSA in a September 2019 response that his medical records had been destroyed. The AOJ then informed the appellant of the unavailability of the Veteran’s SSA records in a September 2020 letter. There has been at least substantial compliance with the Board’s remand directives in that regard. See D’Aries v. Peake, 22 Vet. App. 97, 105 (2008); Stegall v. West, 11 Vet. App. 268 (1998). The Board notes that the Veteran’s former attorney withdrew from representation in December 2018. The appellant subsequently appointed Disabled American Veterans (DAV) as her representative in January 2020, and DAV submitted a brief in support of her appeal in November 2020. Finally, the Board notes that the appellant did not file a VA Form 9 (Appeal to Board of Veterans’ Appeals) in response to a June 2020 statement of the case addressing the issue of the propriety of a reduction in the Veteran’s rating for diabetes mellitus. However, her representative advanced argument as to that issue in his November 2020 brief. Under the circumstances, and in view of the fact that the issue is intertwined with the rating to be assigned for the Veteran’s diabetes, which has been properly perfected for appeal, the Board will exercise its discretion to take jurisdiction of the reduction issue. See Percy v. Shinseki, 23 Vet. App. 37 (2009). New and Material Evidence In general, rating decisions that are not timely appealed are final. See 38 U.S.C. § 7105; 38 C.F.R. § 20.200. From the date of notification of an AOJ decision, a claimant has one year to submit new and material evidence or to initiate an appeal by filing a Notice of Disagreement (NOD) with the decision. The decision becomes final if a claimant does not express disagreement with the decision or if new and material evidence is not associated with the claims file within one year of the date of mailing of the rating decision to the claimant. 38 C.F.R. § 20.302. An exception to this rule is 38 U.S.C. § 5108, which provides that if new and material evidence is presented or secured with respect to a claim which has been disallowed, the Secretary shall reopen the claim and review the former disposition of the claim. The Board must consider the question of whether new and material evidence has been received because it goes to the Board’s jurisdiction to reach the underlying claim and adjudicate the claim de novo. See Jackson v Principi, 265 F.3d 1366 (Fed. Cir. 2001); Barnett v. Brown, 83 F.3d 1380 (Fed. Cir. 1996). “New” evidence is existing evidence not previously submitted to agency decision makers. “Material” evidence is existing evidence that, by itself or when considered with previous evidence of record, relates to an unestablished fact necessary to substantiate the claim. New and material evidence can be neither cumulative nor redundant of the evidence of record at the time of the last prior denial of the claim sought to be reopened, and must raise a reasonable possibility of substantiating the claim. 38 C.F.R. § 3.156(a). In determining whether evidence is new and material, the “credibility of the evidence is to be presumed.” Justus v. Principi, 3 Vet. App. 510, 513 (1992). In order for evidence to be sufficient to reopen a previously disallowed claim, it must be both new and material. If the evidence is new, but not material, the inquiry ends, and the claim cannot be reopened. See Smith v. West, 12 Vet. App. 312, 314 (1999). If it is determined that new and material evidence has been submitted, the claim must be reopened. VA may then proceed to evaluate the merits of the claim on the basis of all evidence of record, but only after ensuring that the duty to assist has been satisfied. See Elkins v. West, 12 Vet. App. 209 (1999). The threshold for determining whether new and material evidence raises a reasonable possibility of substantiating a claim is “low.” See Shade v. Shinseki, 24 Vet. App. 110, 117 (2010). Furthermore, consideration is not limited to whether the newly submitted evidence relates specifically to the reason the claim was last denied, but instead should include whether the evidence could reasonably substantiate the claim were the claim to be reopened, either by triggering the Secretary’s duty to assist or through consideration of an alternative theory of entitlement. Id. at 118. Additionally, the United States Court of Appeals for the Federal Circuit has noted that new evidence could be sufficient to reopen a claim if it could contribute to a more complete picture of the circumstances surrounding the origin of a claimant’s injury or disability, even where it would not be enough to convince the Board to grant a claim. Hodge v. West, 155 F.3d 1356, 1363 (Fed. Cir. 1998). 1. Whether new and material evidence has been submitted sufficient to reopen the Veteran’s claim for service connection for a seizure disorder. The Veteran’s claim of entitlement to service connection for a seizure disorder was initially denied in a July 2012 rating decision. There is no indication that he appealed that decision, or that new and material evidence was received, within one year of the issuance of that decision. Therefore, the July 2012 decision became final. U.S.C. § 7105; 38 C.F.R. § 20.1103. After the July 2012 decision, the Veteran submitted additional statements and evidence supporting his claim, and VA treatment records relevant to his claim were associated with the claims file.  The Board finds that the evidence associated with the claims file after the July 2012 decision could potentially affect the outcome of the Veteran’s claim and is both new and material. Accordingly, the claim for service connection for a seizure disorder is reopened. Service Connection Service connection is warranted where the evidence of record establishes that a particular injury or disease resulting in disability was incurred in the line of duty in the active military service or, if pre-existing such service, was aggravated thereby. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). Generally, in order to prove service connection, there must be competent, credible evidence of (1) a current disability, (2) in-service incurrence or aggravation of an injury or disease, and (3) a nexus, or link, between the current disability and the in-service disease or injury. See, e.g., Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009); Pond v. West, 12 Vet. App. 341 (1999). The requirement of a current disability is satisfied when the claimant is shown to have the disability either at the time he files his claim for service connection, or during the pendency of that claim, even if the disability resolves prior to final adjudication. McClain v. Nicholson, 21 Vet. App. 319, 321 (2007). When the record contains a recent diagnosis of disability prior to the filing of a claim for benefits based on that disability, the report of diagnosis is relevant evidence that must be addressed in determining whether a current disability existed at the time the claim was filed or during its pendency. Romanowsky v. Shinseki, 26 Vet. App. 289, 294 (2013). The term “disability” as used for VA purposes generally contemplates functional impairment resulting in loss of earning capacity. See 38 C.F.R. § 4.1; Saunders v. Wilkie, 886 F.3d 1356 (Fed. Cir. 2018). If a Veteran serves 90 days or more of active, continuous service after December 31, 1946, and manifests certain chronic diseases—including hypertension and organic diseases of the nervous system—to a degree of 10 percent or more during the one-year period following his separation from that service, service connection for the condition may be established on a presumptive basis, notwithstanding that there is no in-service record of the disorder. See 38 U.S.C. §§ 1112, 1113; 38 C.F.R. §§ 3.307, 3.309. Service connection may also be established under 38 C.F.R. § 3.303(b) by (a) evidence of (i) a chronic disease shown as such in service (or within an applicable presumptive period under 38 C.F.R. § 3.307) and (ii) subsequent manifestations of the same chronic disease, or (b) if the fact of chronicity in service in not adequately supported, by evidence of continuity of symptomatology. However, the United States Court of Appeals for the Federal Circuit has held that the provisions of 38 C.F.R. § 3.303(b) relating to continuity of symptomatology can be applied only in cases involving those conditions explicitly recognized as chronic under 38 C.F.R. § 3.309(a). Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). Disability which is proximately due to or the result of a service-connected disease or injury shall also be service connected. 38 C.F.R. § 3.310(a). Establishing service connection on a secondary basis requires evidence sufficient to show: (1) that a current disability exists; and (2) that the current disability was either (a) caused or (b) aggravated by a service-connected disability. 38 C.F.R. § 3.310; Allen v. Brown, 7 Vet. App. 439 (1995). Under applicable law, a Veteran who served on active duty in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, is presumed to have been exposed to an herbicide agent, absent affirmative evidence to the contrary. See 38 C.F.R. § 3.307(a)(6)(iii). VA regulations further provide that service connection is warranted for certain diseases as presumptively due to herbicide exposure. 38 C.F.R. § 3.309(e). A layperson is generally incapable of opining on matters requiring medical knowledge. Routen v. Brown, 10 Vet. App. 183, 186 (1997), aff'd sub nom., Routen v. West, 142 F.3d 1434 (Fed. Cir. 1998). However, lay evidence can be competent and sufficient to establish a diagnosis of a condition when: (1) a layperson is competent to identify the medical condition, (e.g., a broken leg, separated shoulder, pes planus (flat feet), varicose veins, tinnitus (ringing in the ears), etc.), (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). In essence, lay testimony is competent when it pertains to the readily observable features or symptoms of injury or illness and “may provide sufficient support for a claim of service connection.” Layno v. Brown, 6 Vet. App. 465, 469 (1994); see also 38 C.F.R. § 3.159(a)(2). A determination as to whether medical evidence is needed to demonstrate that a Veteran presently has the same condition he or she had in service or during a presumptive period, or whether lay evidence will suffice, depends on the nature of the Veteran’s present condition (e.g., whether the Veteran’s present condition is of a type that requires medical expertise to identify it as the same condition as that in service or during a presumption period, or whether it can be so identified by lay observation). See Barr v. Nicholson, 21 Vet. App. 303, 310 (2007). Thus, medical evidence is not always or categorically required when the determinative issue involves either medical diagnosis or etiology, but rather such issue may, depending on the facts of the particular case, be established by competent and credible lay evidence under 38 U.S.C. § 1154(a). See Davidson, supra. When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the Secretary shall give the benefit of the doubt to the claimant. 38 U.S.C. § 5107; 38 C.F.R. § 3.102. See also Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 1. Entitlement to service connection for hypertension. The appellant contends that the Veteran was entitled to service connection for hypertension, as the condition was due to his exposure to herbicide agents during his service in Vietnam and/or was caused or aggravated by his service-connected disabilities. The record reflects that the Veteran had a current diagnosis of hypertension during the period on appeal. While the Veteran is presumed to have been exposed to herbicide agents during his service in Vietnam, hypertension is not one the diseases that is presumed to be associated with such exposure under 38 C.F.R. § 3.309(e). However, service connection can nevertheless be established if the evidence sufficiently establishes an etiological link between his hypertension and his presumed exposure. Under Section 3 of the Agent Orange Act of 1991, Public Law No. 102-4, 105 Stat. 11, the Secretary of Veterans Affairs entered into an agreement with the National Academy of Sciences (NAS) to review and summarize the scientific evidence concerning the association between exposure to herbicides used in Vietnam and various diseases suspected to be associated with such exposure. The NAS was to determine, to the extent possible, whether there was a statistical association between the suspect disease and herbicide exposure, taking into account the strength of the scientific evidence and the appropriateness of the methods used to detect the association; the increased risk of disease among individuals exposed to herbicides during the service in the Republic of Vietnam during the Vietnam era; and whether there was a plausible biological mechanism or other evidence of a causal relationship between herbicide exposure and the suspect disease. The NAS was required to submit reports of its activities every two years. In Veterans and Agent Orange: Update 11 (2018), the NAS concluded that there was “sufficient evidence” of an association between hypertension and herbicide agents. The sufficient category reflects that “there is enough epidemiologic evidence to conclude that there is a positive association.” See Hypertension Upgraded in Latest Biennial Review of Research on Health Problems in Veterans that May be Linked to Agent Orange Exposure during Vietnam War, The National Academies of Sciences, Engineering, and Medicine (Nov. 15, 2018), http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=25137. This categorization represents a change from hypertension’s previous classification in the category of “limited or suggestive” evidence, meaning that “epidemiologic research results suggest an association between exposure to herbicides and a particular outcome, but a firm conclusion is limited because chance, bias, and confounding factors could not be ruled out with confidence.” Id. Although the NAS has determined there is sufficient evidence of an association between exposure to Agent Orange and hypertension, an etiological connection is not presumed under current law. Instead, additional evidence of such a connection is necessary to show that the Veteran’s development of hypertension is linked to exposure to herbicide agents during his active military service. During a June 2007 VA diabetes examination, the examiner noted that the Veteran had been diagnosed with hypertension in approximately 1982. The examiner indicated that although hypertension was a condition that was potentially related to diabetes, his hypertension was diagnosed many years before he was diagnosed with diabetes. In a June 2011 VA hypertension examination report, an examiner noted that the Veteran had a long history of essential hypertension and indicated that he was on medication for hypertension as early as 1985. The examiner opined the that Veteran’s hypertension was not secondary to his diabetes and stated that the Veteran had been diagnosed with essential hypertension years before the onset of his diabetes. The examiner documented that the Veteran’s hypertension was well controlled and required no increase in medication and that there was no evidence present in the record reflecting that his diabetes aggravated his hypertension beyond its natural progression. During an October 2019 VA hypertension examination, the Veteran reported that he experienced high blood pressure for years before his diagnosis of diabetes in 1992. He indicated that he was able to manage his blood pressure with a “little pill.” The examiner opined that the Veteran’s hypertension was less likely than not caused by his active military service. The examiner noted that his service treatment records did not reveal a diagnosis of hypertension or any cardiovascular disease or dysfunction, and highlighted that his reported diagnosis came well over 20 years after he served in Vietnam. The examiner further opined that it was less likely than not that the Veteran’s hypertension was related to his exposure to Agent Orange during his active military service. The examiner noted the NAS update upgrading the relationship between hypertension and Agent Orange exposure to the category of “sufficient,” but stated that the Veteran had other risk factors including obesity, sedentary lifestyle, male sex, increasing age, and elevated body mass index (BMI) which added to the “workload” of his cardiovascular system. The examiner further stated that the Veteran’s hypertension was not “unusual” and was relatively stable. The examiner concluded that the Veteran’s hypertension was more likely related to his known common risk factors for hypertension, and indicated that he did not have an onset of hypertension within a few years of his exposure to Agent Orange, he did not have nephrotoxic signs, and he did not have malignant hypertensive events or unusual resistance to medication treatments. The examiner stated that, therefore, there was no suggestion of a proximal relationship to herbicide agent exposure. The examiner further opined that the Veteran’s hypertension was less likely than not caused or aggravated by his diabetes mellitus or unspecified depressive disorder. The examiner noted that the Veteran was diagnosed with hypertension before he was diagnosed with diabetes mellitus and that his diabetes therefore could not have caused his hypertension. As to aggravation, the examiner indicated that the Veteran’s hypertension was well managed by a single, monotherapy treatment and had not shown escalation despite variable symptoms related to his diabetes. The examiner stated that, thus, there was no correlation or relationship between the increase in severity of his diabetes and his hypertension symptoms, and the two conditions were independent of each other. The examiner also noted that treatment by vascular medication, such as the medication prescribed for the Veteran’s hypertension, would not be effective if the etiology of his hypertension was related to his mental condition. The examiner indicated that the Veteran’s mental health condition did not aggravate his hypertension, and that the condition was well managed despite escalation and fluctuation of his mental health symptoms over the years. The examiner concluded that there was no correlation or relationship between the Veteran’s hypertension and his unspecified depressive disorder. In light of the foregoing, the Board finds that the preponderance of the evidence is against a finding that the Veteran’s hypertension was related to his active military service, to include his exposure to herbicide agents, or was due to or aggravated by his service-connected disabilities. As noted above, although the most recent NAS update regarding the relationship between exposure to Agent Orange and hypertension found that there was sufficient evidence supporting a positive relationship between the two, hypertension is not a condition that is currently recognized as presumptively due to herbicide agent exposure. Further, the October 2019 examiner opined that his hypertension was more likely due to the Veteran’s numerous other risk factors, based on the nature of his hypertension symptoms and the onset of the condition decades after his service in Vietnam. Additionally, there is no indication from the evidence of record that the Veteran experienced symptoms of hypertension during his active military service or that he was diagnosed with hypertension within one year of his separation from service. The Board also notes that the June 2007, June 2011, and October 2019 examiners all stated that the Veteran’s hypertension was not due to his service-connected diabetes mellitus, as his hypertension had its onset years before he was diagnosed with diabetes. The October 2019 examiner further opined that his hypertension was not aggravated by his diabetes, noting that his hypertension symptoms remained well managed with a single medication despite fluctuation of the severity of his diabetes-related symptoms. The October 2019 examiner additionally opined that the Veteran’s hypertension was not due to his service-connected unspecified depressive disorder, as the condition was managed by a vascular medication and did not fluctuate based on his psychiatric symptoms. The examiner concluded that his hypertension likewise was not aggravated by his unspecified depressive disorder, since his hypertension symptoms did not change despite fluctuation in the severity of his psychiatric symptoms. In sum, the competent and probative evidence of record shows that the Veteran’s hypertension is more likely than not independent from his service-connected diabetes and unspecified depressive disorder. The evidence also indicates that his hypertension is not related to his exposure to Agent Orange while in Vietnam. Absent any competent and probative evidence to the contrary, the Board finds that entitlement to service connection for hypertension is not warranted. 2. Entitlement to service connection for gangrene. The appellant contends that the Veteran was entitled to service connection for gangrene as due to his service-connected diabetes. In his January 2016 Application for Disability Compensation and Related Compensation Benefits, the Veteran indicated that he had been treated for gangrene in 1985. The Board finds that the preponderance of the evidence is against a finding that the Veteran had a current diagnosis of gangrene, or residuals thereof, during the period on appeal. His VA and private treatment records do not make any mention of gangrene related to his diabetes, and do not reflect a diagnosis of gangrene or any residuals related to a previous incidence of gangrene within the period on appeal. Additionally, the Board notes that the Veteran was not diagnosed with diabetes until approximately 1992, several years after his claimed incidence of gangrene. Therefore, there is no indication from the record that the Veteran had a disability related to gangrene during the period on appeal, and entitlement to service connection for gangrene is not warranted. 3. Entitlement to service connection for hearing loss and tinnitus. The appellant contends that the Veteran was entitled to service connection for hearing loss and for tinnitus, as the conditions were due to his exposure to hazardous noise during his active military service. In a June 2015 VA otolaryngology consultation response note, the Veteran indicated that he experienced gradual onset bilateral hearing loss and gradual onset bilateral tinnitus, with an onset “several years” before. He noted that his hearing loss was worse in his right ear. He stated that he was a supply handler in Vietnam during his active military service, and that he was next to the airport with no side preference to noise exposure. He further stated that he held the butt of his gun to his right shoulder during basic training. He indicated that he had noise exposure after service from mowing and farm equipment, as well as from driving a truck for over 30 years with an “exhaust stack,” often with the windows down. He also reported trauma to the top of his head and the right side of his head. He noted that his father wore hearing aids, but did not know the cause of his hearing loss. After conducting audiologic testing, the treating clinician assessed the Veteran with sensorineural hearing loss, with the left side worse than the right. In a March 2016 VA hearing loss and tinnitus examination, the Veteran exhibited puretone thresholds averaging 59 Hertz in his right ear and averaging 66 Hertz in his left ear. The examiner noted his history of noise exposure from his proximity to planes and airport noise without hearing protection, as well as his civilian noise exposure from driving a truck “off and on all his life up until the last few years.” The Veteran also reported a history of head trauma when he wrecked a truck and when he had a separate car accident as a civilian. He indicated that his bilateral tinnitus “began after his time in service.” The examiner documented that the Veteran showed hearing within normal limits at both a June 1965 examination and at a March 1966 examination. The examiner opined that, based on the above evidence, both his bilateral hearing loss and bilateral tinnitus were less likely than not related to his active military service. The examiner noted that he did not associate the onset of his tinnitus with his time during service. Because the examiner was not explicit in describing his rationale, the Board remanded the case for another opinion. In an October 2019 VA hearing loss and tinnitus examination, conducted on remand, the examiner noted that the Veteran exhibited a moderate level of hearing loss at 8000 Hertz on his entrance examination, but otherwise did not exhibit hearing loss in his service treatment records. The examiner indicated that the Veteran’s hearing was normal at the time of his separation from service, and no drop in hearing acuity was found to have occurred during his service. The examiner documented that the Veteran’s hearing loss was first diagnosed in 2015 and stated that he reported a family history of hearing loss and a history of trauma to his head at that time. The examiner indicated that the Veteran had a two-year history of noise exposure during the military, and that he also had noise exposure after his military service from truck driving and farming. The Veteran denied the use of hearing protection during any of his historical noise exposure events. After examining the Veteran and reviewing the record, the examiner opined that the Veteran’s hearing loss was less likely than not related to his active military service. The examiner noted that hearing loss was first documented approximately 50 years after the Veteran’s discharge from military service and indicated that while a separation examination showing normal hearing did not necessarily preclude an etiological connection between service and subsequent hearing loss, there was no evidence of significant changes in his hearing during his military service. The examiner noted that the “Institute of Medicine” (also known as the National Academy of Medicine) had clearly stated that there was no way to predict how much, if any, hearing loss would be sustained if noise exposure occurred. The examiner further noted that hearing damage from noise trauma occurred instantly, which is why the Veteran’s normal hearing thresholds documented at his separation could not be disregarded, particularly when there was no decline in his hearing during his active military service. In view of the foregoing, the Board finds that the preponderance of the evidence is against a finding that the Veteran’s bilateral hearing loss was related to his exposure to hazardous noise during his active military service. The record reflects that the Veteran’s hearing was within normal limits at his separation from service and his hearing loss was not diagnosed until approximate 50 years later. Further, the Veteran indicated that he was exposed to noise after his separation from service, reporting that he drove a truck for over 30 years with an “exhaust stack” and also used farm equipment without the use of hearing protection. While the absence of evidence of any hearing loss during the Veteran’s active military service is not inherently fatal to the claim, the record does not reflect any competent medical evidence indicating that his hearing loss diagnosed decades after his separation from service was related to noise exposure during his time in the military. Additionally, the Board finds that the preponderance of the evidence is against a finding that the Veteran’s tinnitus is related to noise exposure during his active military service. His service treatment records do not indicate any complaints of tinnitus, and the March 2016 examiner noted that the Veteran did not associate his tinnitus with his time in the military. Therefore, the evidence does not show that the Veteran’s bilateral hearing loss or his tinnitus were at least as likely as not related to his active military service, and entitlement to service connection for neither hearing loss nor tinnitus is warranted. Rating Reduction Where a reduction in an evaluation of a service-connected disability is considered warranted and the lower evaluation would result in a reduction or discontinuance of compensation payments currently being made, a rating proposing the reduction or discontinuance must be prepared setting forth all material facts and reasons. In addition, the AOJ must notify the veteran at the veteran’s latest address that he or she has 60 days to present additional evidence showing that compensation should be continued at the present level. 38 C.F.R. § 3.105(e). The procedural framework and safeguards set forth in 38 C.F.R. § 3.105 governing rating reductions are required to be followed by VA before it issues any final rating reduction that would result in a reduction or discontinuance of compensation payments currently being made. See Brown v. Brown, 5 Vet. App. 413, 418 (1993). In a rating reduction case, specifically in those where the rating has been in effect for more than five years, not only must it be determined that an improvement in a disability has actually occurred, but also that the improvement reflects an actual improvement in a veteran’s ability to function under the ordinary conditions of life and work. Brown v. Brown, 5 Vet. App. 413, 420-21; Schafrath v. Derwinski, 1 Vet. App. 589, 594 (1991). A disability rating may not be reduced unless the evidence demonstrates that an improvement in the disability has occurred. 38 U.S.C. § 1155. Specifically, it is necessary to ascertain, based upon a review of the entire recorded history of the condition, whether the evidence reflects an actual change in disability and whether examination reports reflecting change are based upon thorough examinations. In such cases, provided that doubt remains, after according due consideration to all the evidence, the rating agency will continue the rating in effect. 38 C.F.R. § 3.344(b). In considering the propriety of a reduction, the Board must focus on the evidence available to the AOJ at the time the reduction was effectuated, although post-reduction medical evidence may be considered in the context of considering whether actual improvement was demonstrated. Dofflemyer v. Derwinski, 2 Vet. App. 277, 281-82 (1992). 4. Whether the reduction of the Veteran’s rating for diabetes was proper. The appellant contends that the AOJ improperly reduced the Veteran’s rating for his service-connected diabetes from 40 to 20 percent disabling, effective December 1, 2015. As an initial matter, the Board finds that the AOJ complied with the procedural requirements under 38 C.F.R. § 3.105(e). The AOJ proposed to reduce the Veteran’s rating for diabetes mellitus, type II, in an October 2014 rating decision, and confirmed the reduction of his rating from 40 percent to 20 percent, effective December 1, 2015, in a September 2015 rating decision. At the time the reduction became effective, the 40 percent rating for the Veteran’s disability had been continuously in effect for more than five years. Thus, the provisions of 38 C.F.R. § 3.344(a) and (b) are applicable and the question before the Board is whether he exhibited improvement that actually reflected an improvement in his ability to function under the ordinary conditions of life and work during the relevant period. In the June 2007 rating decision which originally assigned a 40 percent disability rating, the AOJ noted that a 40 percent rating was warranted based on his requirement of both insulin and oral medications, restricted diet, and regulation of activities. In a June 2007 VA diabetes examination that formed the basis of the AOJ’s decision, the examiner noted that the Veteran was restricted in his ability to perform strenuous activities, and had trouble controlling his blood sugar levels. The examiner documented that he had to regulate times for his pills, insulin, and exercise very carefully. In a September 2014 VA diabetes examination report, an examiner indicated that the Veteran did not have to regulate his activities due to his diabetes. The examiner noted that he treated his condition with oral medication and two types of insulin, and that he required one to three shots per day. The Veteran reported that he had difficulties with glucose control and stated that he had several instances of low blood sugar levels, but did not have “much in the way of symptoms because it usually happen[ed] at home.” In a March 2016 VA diabetes examination report, the examiner indicated that the Veteran did not have to regulate his activities as part of the medical management of his diabetes. The examiner also noted that the Veteran’s diabetes mellitus would impact his ability to work, as issues related to hypoglycemia would impair strenuous activity. He reported that he had difficulties with glucose control, and would feel and act “like a drunk person” when his blood sugar levels got too low. In an October 2019 VA diabetes examination report, the examiner indicated that the Veteran did not require regulation of activities as part of his medical management for diabetes. The examiner stated that his diabetes would impact his ability to work and noted that his occupation as a truck driver would be restricted or limited due to his use of insulin and hypoglycemia episodes which would disallow him from driving. The examiner documented that the Veteran could suddenly become weak or pass out in an occupational setting, and he reported that his insulin-requiring diabetes mellitus was the reason he lost his commercial driver’s license. Accordingly, the Board finds that the preponderance of the evidence is in favor of a finding that the Veteran’s diabetes mellitus symptoms did not reflect an improvement in his ability to function under the ordinary conditions of life and work during the period on appeal. While the September 2014, the March 2016 and the October 2019 examiners opined that his diabetes did not require regulation of activities, the September 2014 examiner noted his issues with controlling his blood sugar levels and the March 2016 and October 2019 examiners both provided examples of how episodes of hypoglycemia would affect his ability to perform certain activities. The evidence of record fails to show that the Veteran’s diabetes symptoms improved after his June 2007 VA examination, and instead shows that his ability to perform a variety of activities was limited by his difficulties with controlling his blood sugar levels throughout the relevant period. Therefore, the evidence of record reflects that the Veteran’s diabetes symptoms did not materially improve during the period on appeal, and the AOJ’s reduction of his disability rating for the condition from 40 percent disabling to 20 percent disabling was improper. Effective Dates Generally, the effective date for an award of service connection for a disability is the later of the day following separation from active duty or the date entitlement arose if a claim is received within one year after separation from service. Otherwise, the effective date is the date of receipt of claim, or date entitlement arose, whichever is later. The effective date of an award based on a claim reopened after final adjudication shall be fixed in accordance with the facts found, but shall not be earlier than the date of receipt of application therefor. 38 U.S.C. § 5110; 38 C.F.R. § 3.400. A pending claim is an application, formal or informal, which has not been finally adjudicated. 38 C.F.R. § 3.160(c). The pending claims doctrine provides that a claim remains pending in the adjudication process if VA fails to act on it. Norris v. West, 12 Vet. App. 413, 422 (1999). The United States Court of Appeals for Veterans Claims (Court) discussed the caselaw and regulations regarding the scope of a veteran’s claim in DeLisio v. Shinseki, 25 Vet. App. 45 (2011). In relevant part, the Court stated that a claim for VA benefits requires “(1) an intent to apply for benefits, (2) an identification of the benefits sought, and (3) a communication in writing.” Brokowski v. Shinseki, 23 Vet. App. 79, 84 (2009). However, in filing a claim, a claimant is not required to identify a precise medical diagnosis or the medical cause of his condition; rather, he sufficiently files a claim for benefits “by referring to a body part or system that is disabled or by describing symptoms of the disability.” Id. at 86. This is because a claimant is not expected to have medical expertise and generally “is only competent to identify and explain the symptoms that he observes and experiences.” Clemons v. Shinseki, 23 Vet. App. 1, 5 (2009); see also Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007) (noting general competence of laypersons to testify as to symptoms but not medical diagnosis). Effective March 24, 2015, a specific claim in the form prescribed by VA must be filed in order for benefits to be paid or furnished to any individual under the laws administered by VA. See 79 Fed. Reg. 57660 (Sept. 25, 2014). A veteran, or other eligible persons listed in 38 C.F.R. § 3.155(a), who indicates a desire to file for benefits by a communication or action that does not meet the standards of a complete claim is considered to be requesting an application form for benefits under 38 C.F.R. § 3.150(a). 38 C.F.R. § 3.155(a). Upon receipt of such a communication or action, VA shall notify the claimant of the information necessary to complete the application or form prescribed by the Secretary. However, prior to March 24, 2015, a “claim” was defined broadly to include a formal or informal communication in writing requesting a determination of entitlement or evidencing a belief in entitlement to a benefit. 38 C.F.R. § 3.1(p); Brannon v. West, 12 Vet. App. 32, 34 35 (1998); Servello v. Derwinski, 3 Vet. App. 196, 199 (1992). Any communication indicating an intent to apply for a benefit under the laws administered by the VA could be considered an informal claim provided it identified the benefit sought. See 38 C.F.R. § 3.155(a) (2014). To determine when a claim was received, the Board must review all communications in the claims file that may be construed as an application or claim. See Quarles v. Derwinski, 3 Vet. App. 129, 134 (1992). Upon receipt of an informal claim prior to March 24, 2015, if a formal claim had not been filed, the AOJ was to forward an application form to the claimant for execution. If the AOJ received a complete application from the claimant within one year from the date it was sent, then the AOJ would consider it filed as of the date of receipt of the informal claim. 38 C.F.R. § 3.155 (2014). 5. Entitlement to an earlier effective date for the award of service connection for diabetic peripheral neuropathy of the lower extremities. The appellant contends that the Veteran was entitled to an effective date earlier than January 25, 2016 for the award of service connection for diabetic peripheral neuropathy of the lower extremities. The Board finds that the Veteran’s claims for service connection for diabetic peripheral neuropathy of the lower extremities were part and parcel of his claim for an increased rating for his diabetes. See 38 C.F.R. § 4.119, Diagnostic Code 7913, Note (1) (stating that compensable complications of diabetes are to be evaluated separately unless they are part of the criteria to support a 100 percent evaluation). As such, the period under consideration regarding the effective dates for the Veteran’s diabetic peripheral neuropathy is based upon his underlying claim for an increased rating, received by VA on May 13, 2014. In a September 2014 VA diabetes examination, the Veteran reported that he experienced some numbness in his right lateral foot, which was present since he was involved in a motor vehicle accident. He denied symptoms of neuropathy in his right lower extremity. In May and June 2015 VA audiology consultation response notes, the treating clinician documented that the Veteran had a history of diabetes with tingling and numbness in his feet. In a March 2016 VA diabetes examination, the Veteran reported that he intermittently experienced leg cramps, and that his feet would become numb at night while in bed. He further indicated that sitting for prolonged periods caused his legs to become numb. The examiner listed diabetic peripheral neuropathy as a complication of his diabetes mellitus. The Board finds that the record supports a finding that evidence of the Veteran’s diabetic peripheral neuropathy of the right lower extremity and diabetic peripheral neuropathy of the left lower extremity first appeared in the medical evidence of record in a May 6, 2015 VA otolaryngology consultation response note. Although the Veteran had not been formally diagnosed with diabetic peripheral neuropathy at that point, he was competent to report symptoms that were readily observable to a layperson, such as numbness of his extremities. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007) (holding that a layperson is competent to identify observable symptoms). As his complaints of such symptoms were eventually utilized to diagnose him with diabetic peripheral neuropathy, the Board finds that the evidence supports a finding that diabetic peripheral neuropathy of the lower extremities had its onset prior to his initial diagnosis at the March 2016 VA diabetes examination. As the date that entitlement arose for these conditions occurred after the May 2014 claim for increased rating, and as the conditions are considered part and parcel of that claim, entitlement to an effective date of May 6, 2015 is warranted. The preponderance of the evidence is against a still-earlier date, however. Simply put, none of the competent and probative evidence reflects the presence of diabetic peripheral neuropathy of the lower extremities prior to May 6, 2015. Increased Ratings Disability ratings are determined by application of the criteria set forth in VA’s Schedule for Rating Disabilities, which is based on average impairment of earning capacity. 38 U.S.C. § 1155; 38 C.F.R. Part 4. When a question arises as to which of two ratings applies under a particular diagnostic code, the higher rating is assigned if the disability more closely approximates the criteria for the higher rating. Otherwise, the lower rating applies. 38 C.F.R. § 4.7. After careful consideration of the evidence, any reasonable doubt remaining is resolved in favor of the Veteran. 38 C.F.R. § 4.3. Pertinent regulations do not require that all cases show each finding specified by the criteria present in the Rating Schedule, but instead requires that findings are sufficiently characteristic to identify the disease and the resulting disability, as well as coordination of the rating with the relevant impairment of function. 38 C.F.R. § 4.21. Therefore, the Board has considered the potential application of various other provisions of the regulations governing VA benefits, whether or not they were raised by the Veteran or appellant, in reaching its decision. Schafrath v. Derwinski, 1 Vet. App. 589, 595 (1991). In considering the severity of a disability, it is essential to trace the medical history. 38 C.F.R. §§ 4.1, 4.2, 4.41. Consideration of the whole-recorded history is necessary so that a rating may accurately reflect the elements of any disability present. 38 C.F.R. § 4.2; Peyton v. Derwinski, 1 Vet. App. 282 (1991). Although the regulations do not give past medical reports precedence over current findings, the Board is to consider a veteran’s medical history in determining the applicability of a higher rating for the entire period in which the appeal has been pending. Powell v. West, 13 Vet. App. 31, 34 (1999). Where entitlement to compensation has already been established and an increase in the disability rating is at issue, it is the present level of disability that is of primary concern. Francisco v. Brown, 7 Vet. App. 55 (1994). Nevertheless, the Board acknowledges that a claimant may experience multiple distinct degrees of disability that might result in different levels of compensation from the time the increased rating claim was filed until a final decision is made. Hart v. Mansfield, 21 Vet. App. 505 (2007). When adjudicating an increased rating claim, the relevant time period for consideration is the time period beginning one year before the claim was filed. See 38 C.F.R. § 3.400(o); Hart, 21 Vet. App. at 509. The Board must also assess the competence and credibility of lay statements and testimony. Barr v. Nicholson, 21 Vet. App. 303, 308 (2007). In increased rating claims, a veteran’s lay statements alone, absent a negative credibility determination, may constitute competent evidence of worsening, at least with respect to observable symptoms. See Vazquez-Flores v. Shinseki, 24 Vet. App. 94, 102 (2010), rev’d on other grounds by Vazquez-Flores v. Shinseki, 580 F.3d 1270, 1277 (Fed. Cir. 2009). As such, the Board will analyze the evidence of record to determine the Veteran’s current levels of disability. Although the Board has an obligation to provide reasons and bases supporting its decision, there is no obligation to discuss, in detail, the extensive evidence of record. Gonzales v. West, 218 F.3d 1378, 1380-81 (Fed. Cir. 2000) (holding that the Board must review the entire record, but does not have to discuss each piece of evidence). Therefore, the Board will summarize the relevant evidence where appropriate, and the Board’s analysis will focus specifically on what the evidence shows, or fails to show, as it relates to the claims. 6. Entitlement to higher ratings for diabetic peripheral neuropathy of the lower extremities. The appellant contends, in essence, that the Veteran was entitled to a rating in excess of 10 percent each for the diabetic peripheral neuropathy of his lower extremities, as his symptoms more nearly approximated the criteria for a higher rating. He is currently rated as 10 percent for his right lower extremity and 10 percent for his left lower extremity under Diagnostic Code 8520 throughout the period on appeal. Under Diagnostic Code 8520, a 10 percent rating is warranted for mild incomplete paralysis of the sciatic nerve, a 20 percent rating is warranted for moderate incomplete paralysis of the sciatic nerve, a 30 percent rating is warranted for moderately severe incomplete paralysis of the sciatic nerve, and a 60 percent rating is warranted for severe incomplete paralysis of the sciatic nerve, with marked muscular atrophy. 38 C.F.R. § 4.124a. The term “incomplete paralysis” indicates a degree of lost or impaired function substantially less than the type picture for complete paralysis given for each nerve, whether due to varied level of the nerve lesion or to partial regeneration. When the involvement is wholly sensory, the rating should be for the mild, or at most, the moderate degree. 38 C.F.R. § 4.124a. The Board also notes that the terms “mild,” “moderate,” and “moderately severe” are not defined in the Schedule. Rather than applying a mechanical formula, the Board must evaluate all of the evidence to the end that its decisions are “equitable and just.” 38 C.F.R. § 4.6. As noted above, in May and June 2015 VA audiology consultation response notes, the treating clinician documented that the Veteran had a history of diabetes with tingling and numbness in his feet. He also reported in a March 2016 VA diabetes examination that he intermittently experienced leg cramps, and that his feet would become numb at night while in bed or when sitting for prolonged periods. In a March 2016 VA diabetic peripheral neuropathy examination, the examiner documented that the Veteran experienced mild paresthesias and/or dysesthesias of his right and left lower extremities. The examiner also noted that the Veteran experienced mild numbness of his lower extremities, and indicated that he had decreased deep tendon reflexes in his right and left ankles. The examiner additionally stated that he showed decreased position sense of his right and left lower extremities and decreased vibration sensation of his right and left lower extremities. The examiner indicated that the Veteran exhibited mild incomplete paralysis of the sciatic nerves of his right and left lower extremities. In an October 2019 VA diabetic peripheral neuropathy examination, the examiner indicated that the Veteran experienced symptoms of mild paresthesias and/or dysesthesias and mild numbness of his right and left lower extremities. The examiner further documented that he exhibited decreased light touch testing results, decreased vibration sensation, and decreased cold sensation of his right and left lower extremities. The examiner noted that his deep tendon reflexes were all normal. The examiner opined that the Veteran had mild incomplete paralysis of his right and left sciatic nerves. The examiner stated that the Veteran’s diabetic peripheral neuropathy would have a mild impact on gainful physical occupation, as he might have difficulty feeling pedals of a motor vehicle. The examiner indicated that diabetic peripheral neuropathy would have no impact on gainful sedentary occupation, and would carry no occupational restrictions in an office setting or desk job. In light of the totality of the record, the Board finds that the preponderance of the evidence is against a finding that the Veteran experienced symptoms related to the diabetic peripheral neuropathy of his lower extremities during the period on appeal that were more than mild in severity. The evidence of record indicates that he experienced symptoms such as numbness and tingling in his lower extremities, and medical testing reflected decreased sensation in each lower extremity. VA medical examiners characterized the severity of his peripheral neuropathy as mild in March 2016 and October 2019 examinations. The symptoms described in the record were primarily sensory and did not reflect a level of paralysis of either lower extremity greater than that which has been characterized as mild. While the March 2016 examiner documented that the Veteran had decreased deep tendon reflexes in his right and left ankles, the October 2019 examiner did not observe such symptoms. Additionally, no muscle atrophy was noted during the period on appeal, which would indicate a decreased usage of all or part of his lower extremities. The Board finds that the Veteran’s description of limited symptoms such as numbness and tingling of his lower extremities, combined with the VA examiners’ opinions that his symptoms related to his diabetic peripheral neuropathy were of mild severity, reflect that the diabetic peripheral neuropathy of the right and left lower extremities most nearly approximated mild incomplete paralysis of his right and left sciatic nerves. A rating in excess of 10 percent is not warranted for either extremity. 7. Entitlement to an increased rating for diabetes. The appellant contends, in essence, that the Veteran was entitled to an increased rating for his diabetes, as his symptoms more nearly approximated the criteria for a higher rating. In accordance with the Board’s findings herein, he is currently rated as 40 percent disabled under Diagnostic Code 7913 throughout the period on appeal. As noted above, under Diagnostic Code 7913, a 40 percent rating is warranted for diabetes mellitus requiring one or more daily injections of insulin, restricted diet, and regulation of activities (avoidance of strenuous occupational and recreational activities). Id. A 60 percent rating is warranted for diabetes mellitus requiring one or more daily injections of insulin, restricted diet, and regulation of activities with episodes of ketoacidosis or hypoglycemic reactions requiring one or two hospitalizations per year or twice per month visits to a diabetic care provider, plus complications that would not be compensable if separately evaluated. Id. A 100 percent rating is warranted for diabetes mellitus requiring more than one daily injection of insulin, restricted diet, and regulation of activities with episodes of ketoacidosis or hypoglycemic reactions requiring at least three hospitalizations per year or weekly visits to a diabetic care provider, plus either progressive loss of weight and strength or complications that would be compensable if separately evaluated. Id. In a September 2014 and March 2016 VA diabetes examinations, the respective examiners each noted that the Veteran required a prescribed oral hypoglycemic agent and more than one injection of insulin per day to treat his diabetes. The examiners documented that he visited his diabetic care provider for episodes of ketoacidosis less than two times per month, and that he visited his diabetic care provider for episodes of hypoglycemia less than two times per month. The examiners indicated that he had not been hospitalized for episodes of ketoacidosis or hypoglycemic reactions over the prior 12 months and stated that he did not have a progressive unintentional weight loss or loss of strength attributable to his diabetes. The examiners noted that he also had recognized complications of diabetes, including diabetic retinopathy and erectile dysfunction. The September 2014 examiner stated that the Veteran had some issues related to fatigability and hypoglycemia, and the March 2016 examiner stated that some of the Veteran’s issues related to hypoglycemia would impair strenuous activity. In an October 2019 VA diabetes examination report, the examiner documented that the Veteran managed his diabetes with a restricted diet, prescribed oral hypoglycemic agent, and more than one insulin injection per day. The examiner indicated that the Veteran visited his diabetic care provider for episodes of ketoacidosis less than two times per month, and that he visited his diabetic care provider for episodes of hypoglycemia less than two times per month. The examiner noted that the Veteran had not been hospitalized for episodes of ketoacidosis or hypoglycemic reactions over the prior 12 months and stated that he did not have a progressive unintentional weight loss or loss of strength attributable to his diabetes. The examiner stated that the Veteran also had recognized complications of diabetic peripheral neuropathy and erectile dysfunction. The examiner indicated that the Veteran’s ability to function in his traditional occupation as a commercial truck driver would be restricted or limited due to his use of insulin and hypoglycemic episodes. The Veteran reported hypoglycemic attacks several times per month, which he was able to manage at home and for which he had not been hospitalized or required to visit his medical provider for assistance. He stated that he was confident in his wife’s and daughter’s assistance and would prefer not to have doctors assist him. The Board finds that the preponderance of the evidence is against a finding that the Veteran’s diabetes satisfied the criteria for a rating in excess of 40 percent. Although the record reflects that he experienced problems managing his blood sugar levels and had episodes of hypoglycemia, there is no indication that he was ever hospitalized in relation to ketoacidosis or hypoglycemia. In addition, he indicated that he was able to manage his hypoglycemic events at home, without the aid of his medical provider. Therefore, a rating in excess of 40 percent is not warranted. REASONS FOR REMAND 1. Entitlement to service connection for a seizure disorder is remanded. The appellant contends that the Veteran was entitled to service connection for a seizure disorder, as the condition was due to or aggravated by his service-connected diabetes. As discussed above, new and material evidence has been associated with the claims file since the current claim was initiated, and the Board notes that there is no VA medical opinion of record which addresses whether the Veteran’s seizure disorder was caused or aggravated by his diabetes. Under McClendon v. Nicholson, 20 Vet. App. 79, 81 (2006), a VA medical examination or opinion must be provided when there is (1) competent evidence of a current disability or persistent or recurrent symptoms of a disability, and (2) evidence establishing that an event, injury, or disease occurred in service or establishing certain diseases manifesting during an applicable presumptive period for which the claimant qualifies, and (3) an indication that the disability or persistent or recurrent symptoms of a disability may be associated with the veteran’s service or with another service-connected disability, but (4) insufficient competent medical evidence on file for the Secretary to make a decision on the claim. See 38 U.S.C. § 5103A(d)(2); 38 C.F.R. § 3.159(c)(4)(i). The third prong, which requires that the evidence of record “indicate” that the claimed disability or symptoms “may be” associated with the established event, is a low threshold. McClendon, 20 Vet. App. at 83. The record reflects that the Veteran was diagnosed with a seizure disorder during the period on appeal, which he claimed was related to hypoglycemic episodes associated with his diabetes. The Veteran’s VA treatment records frequently note that he associated his instances of seizures with low blood sugar, and a September 2017 VA neurology clinic physician note stated that he “likely ha[d] focal epilepsy, and hypoglycemia lowers the seizure threshold and he ha[d] breakthrough seizures in the setting of hypoglycemia.” Therefore, the medical evidence of record indicates that the Veteran’s seizure disorder was potentially related to his diabetes, but it is unclear if the condition was caused by his service-connected disability or otherwise aggravated beyond its natural progression by his diabetes. A remand is necessary for a medical opinion which addresses the nature and etiology of his seizure disorder. 2. Entitlement to a TDIU. The appellant contends that the Veteran was entitled to a TDIU, as his service-connected disabilities rendered him unable to obtain and maintain substantially gainful employment during the period on appeal. The Board notes that the Veteran was assigned a 100 percent schedular disability rating for his unspecified depressive disorder, effective January 25, 2016. A TDIU is considered a lesser benefit than a 100 percent schedular rating, and the award of a 100 percent schedular rating generally renders the issue of entitlement to a TDIU moot for the period during which the 100 percent schedular rating is in effect. An exception to this is that a separate award of TDIU predicated on a single disability, when considered together with another disability separately rated at 60 percent or greater, may warrant payment of special monthly compensation (SMC) under 38 U.S.C. § 1114(s).  Bradley v. Peake, 22 Vet. App. 280 (2008).  In this case, the Veteran is already rated as 100 percent disabled for a single disability; however, he previously asserted that he was forced to quit his occupation as a commercial truck driver due to his diabetes. Further, VA medical examiners have indicated that his diabetes symptoms, and symptoms of his service-connected disabilities related to his diabetes, would have limited his ability to drive a vehicle, and would have interfered with his ability to otherwise maintain gainful employment. Additionally, the Veteran’s claim for entitlement to an increased rating for diabetes, which inherently included a claim for entitlement to a TDIU under Rice v. Shinseki, 22 Vet. App. 447, 454 (2009), was received by VA in May 2014. See Rice, 22 Vet. App. at 454 (when entitlement to TDIU is raised during the appeal of a rating for a disability, it is part of the claim for benefits for the underlying disability). Thus, the relevant period for consideration of entitlement to a TDIU precedes the effective date of the 100 percent rating for his unspecified depressive disorder. As the Veteran previously indicated that he was unable to work during and prior to the period on appeal as a result of his disabilities, in particular his diabetes, the Board finds that the issue of entitlement to a TDIU has been raised by the record and is still an undecided part of the instant appeal. Total disability will be considered to exist when there is present any impairment of mind or body which is sufficient to render it impossible for the average person to follow a substantially gainful occupation. 38 C.F.R. § 3.340. If the total rating is based on a disability or combination of disabilities for which the Schedule for Rating Disabilities provides an evaluation of less than 100 percent, it must be determined that the service-connected disabilities are sufficient to produce unemployability without regard to advancing age. 38 C.F.R. § 3.341. A total disability rating may be assigned where the combined rating for the Veteran’s service-connected disabilities is less than total if the disabled Veteran is unable to secure or follow a substantially gainful occupation as a result of service-connected disabilities. Specifically, if there is only one such disability, this disability shall be ratable at 60 percent or more; if there are two or more disabilities, there shall be at least one ratable at 40 percent or more and sufficient additional disability to bring the combined rating to 70 percent or more. 38 C.F.R. §§ 3.340, 3.341, 4.16(a). For the purpose of defining a disability of either 60 percent or 40 percent under 38 C.F.R. § 4.16(a), the following will be considered one disability: (1) disabilities of one or both upper extremities, or of one or both lower extremities, including the bilateral factor, if applicable; (2) disabilities resulting from common etiology or a single incident; (3) disabilities affecting a single body system (e.g., orthopedic, digestive, respiratory, cardiovascular-renal, neuropsychiatric); (4) multiple injuries incurred in action; or (5) multiple injuries incurred as a prisoner of war. 38 C.F.R. § 4.16(a). The Board also notes that prior to the assignment of the 100 percent disability rating for the Veteran’s unspecified depressive disorder, his total combined disability rating did not meet the 60 percent threshold for entitlement to a TDIU on a schedular basis due to multiple service-connected disabilities, even when considering the Board’s findings herein. However, the Board is remanding the issue of entitlement to service connection for a seizure disorder, which could potentially increase his combined disability rating for that period. As such, the issue of entitlement to a TDIU is also inextricably intertwined with the issue of entitlement to service connection for a seizure disorder and must likewise be remanded. See Harris v. Derwinski, 1 Vet. App. 180, 183 (1991) (two issues are “inextricably intertwined” when they are so closely tied together that a final Board decision on one issue cannot be rendered until the other issue has been considered). Finally, the Board notes that a finding in favor of entitlement to a TDIU solely as due to the Veteran’s diabetes, or a finding that he is entitled to a TDIU based on multiple disabilities for any applicable period that his combined disability rating fails to meet the schedular criteria, would require that the finding be made on an extraschedular basis. Entitlement to a TDIU can be awarded on an extraschedular basis under 38 C.F.R. § 4.16(b) if it is determined that a veteran is unemployable by reason of service-connected disability but fails to meet the percentage standards set forth in 38 C.F.R. § 4.16(a). However, the Board cannot consider such entitlement in the first instance. Instead, the claim must be remanded so that it can be referred to the Director of the Compensation Service for initial consideration. Bowling v. Principi, 15 Vet. App. 1 (2001). Based on the evidence detailed above, the Board concludes there is plausible evidence supporting a claim for a TDIU on an extraschedular basis, so as to warrant referral to the Director of the Compensation Service for consideration. Thus, on remand—unless action on the claim for service connection for a seizure disorder alters the analytical landscape so as to make such a referral unnecessary—the AOJ should refer the appellant’s case to the Director of the Compensation Service for extraschedular consideration of entitlement to a TDIU under 38 C.F.R. § 4.16(b) during the period on appeal, to include as solely due to the Veteran’s service-connected diabetes. These matters are REMANDED for the following action: 1. Make arrangements to provide the record on appeal to an appropriately qualified clinician for purposes of obtaining a medical opinion as to the nature and etiology of any seizure disorder the Veteran may have had. After reviewing the record, the clinician should provide an opinion as to whether it is at least as likely as not (i.e., whether it is 50 percent or more probable) that any seizure disorder diagnosed during the period on appeal was related to the Veteran’s military service, to include as being due to, or aggravated by, a service-connected disability. In so doing, the examiner should specifically discuss the fact that the Veteran’s VA treatment records frequently note that he associated his instances of seizures with low blood sugar. The examiner should also consider and discuss a September 2017 VA neurology clinic physician note indicating that the Veteran “likely ha[d] focal epilepsy, and hypoglycemia lowers the seizure threshold and he ha[d] breakthrough seizures in the setting of hypoglycemia.” The examiner is advised that the Veteran was competent, and the appellant is competent, to report symptoms, treatment, and injuries observable to a layperson. Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). The examiner is also reminded that the absence of documented treatment in service or thereafter is not fatal to a service connection claim, and the absence of evidence in the service treatment records is an insufficient basis, by itself, for a negative opinion. See Ledford v. Derwinski, 3 Vet. App. 87, 89 (1992). Thus, the examiner is to consider the totality of the record, and not just the absence of clinical treatment, in weighing the Veteran’s statements asserting symptomatology. The examiner must provide a comprehensive rationale for all opinions expressed and discuss relevant evidence where appropriate. If the examiner cannot provide the requested opinion without resorting to speculation, it must be so stated, and the examiner must provide the reasons why an opinion would require speculation. Specifically, the examiner must indicate whether there was a further need for information or testing, or whether an opinion could not be rendered due to limitations of knowledge in the medical community at large. 2. Thereafter—unless action on the claim for service connection for a seizure disorder alters the analytical landscape so as to make such a referral unnecessary—refer the case to the Director of the Compensation Service for consideration of a TDIU on an extraschedular basis under 38 C.F.R. § 4.16(b). The Director should be asked to consider whether the Veteran was entitled to a TDIU during the period on appeal solely based on his service-connected diabetes mellitus, and any associated disabilities encompassed under 38 C.F.R. § 4.16. The Director should also be asked to offer an opinion regarding whether the Veteran was otherwise entitled to a TDIU on an extraschedular basis prior to January 25, 2016, if applicable. 3. After completing the above, and any other development as may be indicated by any response received as a consequence of the actions taken in the preceding paragraphs, the issues remaining on appeal should be readjudicated based on the entirety of the evidence. If any benefit sought remains denied, the appellant and her representative should be issued a supplemental statement of the case. An   appropriate period of time should be allowed for response. DAVID A. BRENNINGMEYER Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board S. Ferguson, Associate Counsel The Board’s decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.