Citation Nr: 21068768 Decision Date: 11/12/21 Archive Date: 11/12/21 DOCKET NO. 18-17 601 DATE: November 12, 2021 ORDER Service connection for sleep apnea is granted. Entitlement to a 20 percent rating for lumbosacral strain with degenerative arthritis prior to July 3, 2018 is granted. Entitlement to a rating in excess of 40 percent for lumbosacral strain with degenerative arthritis from July 3, 2018 is denied. Entitlement to a rating in excess of 10 percent for left lower extremity diabetic neuropathy prior to January 3, 2020 is denied. Entitlement to a rating in excess of 20 percent for left lower extremity diabetic neuropathy from January 3, 2020 is denied. Entitlement to a rating in excess of 10 percent for right lower extremity diabetic neuropathy prior to January 3, 2020 is denied. Entitlement to a rating in excess of 20 percent for right lower extremity diabetic neuropathy from January 3, 2020 is denied. A total disability rating based on individual unemployability due to service-connected disabilities (TDIU) is granted. FINDINGS OF FACT 1. The Veteran's sleep apnea has its onset in service. 2. Prior to July 3, 2018, considering the Veteran's pain and corresponding functional impairment, including during flare-ups, the Veteran's lumbosacral strain with degenerative arthritis is productive of approximately forward flexion greater than 30 degrees but not greater than 60 degrees. 3. From July 3, 2018, considering the Veteran's pain and corresponding functional impairment, his back disability is manifested by disability analogous to forward flexion of 30 degrees or less; however, the preponderance of the evidence shows that the Veteran's disability is not manifested by the functional equivalent of ankylosis, including during flare-ups. 4. Prior to January 3, 2020, the Veteran's left lower extremity diabetic neuropathy is characterized by mild incomplete paralysis. 5. From January 3, 2020, the Veteran's left lower extremity diabetic neuropathy is characterized by moderate incomplete paralysis. 6. Prior to January 3, 2020, the Veteran's right lower extremity diabetic neuropathy is characterized by mild incomplete paralysis. 7. From January 3, 2020, the Veteran's right lower extremity diabetic neuropathy is characterized by moderate incomplete paralysis. 8. It is reasonably shown that the Veteran's service-connected disabilities preclude him from securing or following a substantially gainful occupation. CONCLUSIONS OF LAW 1. The criteria for service connection for sleep apnea have been met. 38 U.S.C. §§ 1101, 1110, 5103, 5107; 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.310. 2. The criteria for a 20 percent rating for lumbosacral strain with degenerative arthritis prior to July 3, 2018 have been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.102, 4.1, 4.30, 4.40, 4.45, 4.59 4.71a, Diagnostic Code (DC) 5237. 3. The criteria for a rating in excess of 40 percent for lumbosacral strain with degenerative arthritis from July 3, 2018 have not been met. 38 C.F.R. §§ 3.102, 4.1, 4.7, 4.10, 4.40, 4.45, 4.71a, DC 5237. 4. The criteria for a rating in excess of 10 percent for left lower extremity diabetic neuropathy prior to January 3, 2020 have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.159, 4.1, 4.2, 4.10, 4.123, 4.124, 4.124a, DC 8520. 5. The criteria for a rating in excess of 20 percent for left lower extremity diabetic neuropathy from January 3, 2020 have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.159, 4.1, 4.2, 4.10, 4.123, 4.124, 4.124a, DC 8520. 6. The criteria for a rating in excess of 10 percent for right lower extremity diabetic neuropathy prior to January 3, 2020 have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.159, 4.1, 4.2, 4.10, 4.123, 4.124, 4.124a, DC 8520. 7. The criteria for a rating in excess of 20 percent for right lower extremity diabetic neuropathy from January 3, 2020 have not been met. 38 U.S.C. §§ 1155, 5107; 38 C.F.R. §§ 3.159, 4.1, 4.2, 4.10, 4.123, 4.124, 4.124a, DC 8520. 8. The criteria for entitlement to a TDIU have been met. 38 U.S.C. §§ 1155, 5107(b); 38 C.F.R. §§ 3.102, 4.16. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty in the United States Air Force from June 1967 to February 1971 and in the United States Army from June 1984 to April 1988, August 2000 to August 2003 and May 2004 to May 2005. The Veteran presented sworn testimony at a hearing before the undersigned in February 2020. These matters were previously remanded by the Board in April 2020 for further development. Effective February 7, 2021, VA revised the criteria for evaluating musculoskeletal disorders. See Schedule for Rating Disabilities: Musculoskeletal System and Muscle Injuries, 85 Fed. Reg. 76453, 76464 (Nov. 30, 2020); Correction, 86 Fed. Reg. 8142, 8143 (Feb. 4, 2021) (changing new diagnostic code applicable to plantar fasciitis from 5285 to 5269). VA's General Counsel has held that where a law or regulation changes during the pendency of a claim for a higher rating, the Board must first determine whether the revised version is more favorable to the veteran. In so doing, it may be necessary for the Board to apply both the old and new versions of the regulation. If the revised version of the regulation is more favorable, the retroactive reach of that regulation under 38 U.S.C. § 5110(g) can be no earlier than the effective date of that change. The Board must generally apply both the former and the revised versions of the regulation for the period prior and subsequent to the regulatory change, but an effective date based on the revised criteria may be no earlier than the date of the change. VA thus must consider the claim for a higher rating pursuant to the former and revised regulations during the latter part of this appeal. See VAOPGCPREC 3 2000, 65 Fed. Reg. 33,422 (2000); DeSousa v. Gober, 10 Vet. App. 461, 467 (1997). Therefore, the Board will consider the Veteran's claim under the old criteria prior to February 7, 2021 and both the old and new rating criteria from February 7, 2021. The criteria that is more favorable to the Veteran will be applied. In this regard, the Board observes that former regulation 38 C.F.R. § 19.9(b)(2) (now renumbered as 38 C.F.R. § 20.904(d)(2)) provided that the Board has the authority to consider appeals in light of laws, including but not limited to statutes, regulations and court decisions that were not previously considered by the agency of original jurisdiction. In Disabled American Veterans v. Sec of Veterans Affairs, 327 F.3d 1339 (Fed. Cir. 2003), the United States Court of Appeals for the Federal Circuit (Federal Circuit) specifically upheld the validity of 38 C.F.R. § 19.9(b)(2) (now as noted renumbered as 38 C.F.R. § 20.904(d)(2)). Id. at 1349. As such, pursuant to 38 C.F.R. § 20.904(d)(2), the Board will proceed to adjudicate the Veteran's claim. Disability ratings are determined by applying the criteria set forth in the VA Schedule for Rating Disabilities. 38 U.S.C. § 1155; 38 C.F.R. Part 4. Ratings are assigned based on the average impairment of earning capacity resulting from a service-connected disability. 38 C.F.R. § 4.1. Where two disability ratings are potentially applicable, the higher rating will be assigned if the disability picture more nearly approximates the criteria required for that rating. Otherwise, the lower rating will be assigned. 38 C.F.R. § 4.7. After careful consideration of the evidence, any reasonable doubt remaining will be resolved in favor of the Veteran. 38 C.F.R. § 4.3. Service Connection Service connection may be granted for a disability resulting in a disease or injury that is incurred in or aggravated by active military service. 38 U.S.C. § 1110; 38 U.S.C. § 3.303. To establish service connection for the claimed disorder, the following criteria must be met: (1) evidence of a current disability; (2) evidence of an in-service incurrence or aggravation of a disease or injury; and (3) evidence of a nexus between the claimed in-service disease or injury and current disability. See 38 C.F.R. § 3.303; see also Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009); Shedden v. Principi, 381 F.3d 1163, 1166-67 (Fed. Cir. 2004); Hickson v. West, 12 Vet. App. 247, 253 (1999). In addition to the elements of direct service connection, service connection may also be granted on a secondary basis for a disability if it is proximately due to or the result of a service-connected disease or injury. 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) proximately caused by or (b) proximately aggravated by a service-connected disability. Allen v. Brown, 7 Vet. App. 439, 448 (1995) (en banc). In making all determinations, the Board must fully consider the lay assertions of record. A layperson is competent to report on the onset and continuity of his current symptomatology. See Layno v. Brown, 6 Vet. App. 465, 470 (1994) (a Veteran is competent to report on that of which he or she has personal knowledge). Lay evidence can also be competent and sufficient evidence of a diagnosis or to establish etiology if (1) the layperson is competent to identify the medical condition; (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. Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009); Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). When considering whether lay evidence is competent, the Board must determine, on a case by case basis, whether the Veteran's particular disability is the type of disability for which lay evidence may be competent. Kahana v. Shinseki, 24 Vet. App. 428 (2011); see also Jandreau, 492 F.3d at 1376-77. 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. Service connection for sleep apnea The Veteran asserts that he is entitled to service connection for sleep apnea that began in service or alternatively is the result of a service-connected condition to include, unspecified depressive disorder. After service, the Veteran has received treatment for depression and reports he had sleep problems after returning from service. In the April 2020 BVA remand, the Board held clarity was needed regarding whether the Veteran's diagnosed sleep apnea and sleep symptoms were caused ot aggravated by his service-connected psychiatric condition. The claim was remanded for an examination and associated medical nexus opinion. The Veteran was previously provided a BVA Medical opinion in February 2018, in which the VA examiner opined that hypertension does not cause sleep apnea, there is no medical basis for this association as sleep apnea may contribute to worsening of hypertension, but hypertension does not cause nor aggravate sleep apnea. As hypertension does not affect the upper airways, it was less likely than not Veteran's sleep apnea was secondarily related to hypertension. See February 2018 C&P Exam. Post-remand, the Veteran was afforded a VA Sleep Apnea examination in November 2020. The obstructive sleep apnea (OSA) diagnosis was reaffirmed, with a date of diagnosis in October 2015, based on a sleep study performed. The VA examiner held that Veteran's sleep apnea was less likely than not caused directly by an in-service injury or event because service treatment records showed no complaints, treatment or diagnoses of the condition and the initial diagnosis was made years after discharge from service. As to whether the sleep apnea was caused or aggravated by Veteran's service-connected psychiatric disorder, the VA examiner opined negatively and stated insomnia or hypersomnia do occur in people with depressive disorders, but not in sleep apnea. The risk factors for OSA are multifactorial, but does not include depression, back strain or radiculopathy. As such, the examiner concluded that the OSA was not proximately due to any of Veteran's service-connected conditions. See November 2020 C&P Exam. The Veteran also submitted a private positive medical nexus opinion in support of his claim in December 2020. The private doctor opined that Veteran developed a sleep disorder, PTSD, restless leg syndrome as a result of constant air strip noise while in service, and the sleep disorder in and of itself is enough to precipitate obesity as well as major depressive disorder which can cause obesity and musculoskeletal problems which cause obesity secondarily. The doctor opined that it is as likely as not that OSA is related to Veteran's military service both as a primary condition and as a secondary condition linked to his musculoskeletal problems and his major depressive disorder. See December 2020 Medical Treatment Record. Veteran additionally submitted literature in support of his claim, which links sleep problems and sleep apnea symptoms with PTSD, with an outsized risk for younger veterans with PTSD screening positive for OSA. See October 2021 Correspondence. The Board acknowledges the VA examination and subsequent medical opinions that have provided negative nexus opinions in regard to the Veteran's claim for service connection. The Board also considers the positive medical nexus opinion provided in support of Veteran's claim. In addition to the conflicting medical evidence, the Board finds that the Veteran is competent to report the frequent sleeping issues and other symptomatology of his OSA during and since service and finds his statements to be credible. Further, there is no doubt that the Veteran has been diagnosed as having OSA. Here, even though the VA examiner has rendered a negative nexus opinion regarding the direct in-service etiology and secondary etiology of the Veteran's sleep apnea, the Board concludes that there is sufficient evidence to resolve reasonable doubt in the Veteran's favor and therefore a remand is not necessary to obtain another medical opinion as the available evidence is sufficient for that purpose. Indeed, the Veteran report of symptoms since service is competent and credible. After resolving any doubt in the Veteran's favor, the Board finds that the evidence sufficiently establishes that the Veteran's current sleep apnea had its onset in service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303(a). Thus, all three elements necessary to establish service connection have been met. Increased Rating Disability ratings are determined by applying the criteria set forth in the VA Schedule for Rating Disabilities. 38 U.S.C. § 1155; 38 C.F.R. Part 4. Ratings are assigned based on the average impairment of earning capacity resulting from a service-connected disability. 38 C.F.R. § 4.1. Where two disability ratings are potentially applicable, the higher rating will be assigned if the disability picture more nearly approximates the criteria required for that rating. Otherwise, the lower rating will be assigned. 38 C.F.R. § 4.7. After careful consideration of the evidence, any reasonable doubt remaining will be resolved in favor of the Veteran. 38 C.F.R. § 4.3. In deciding this appeal, the Board has considered whether separate ratings for different periods of time, based on the facts found, are warranted, a practice of assigning ratings referred to as "staging the ratings." See Fenderson v. West, 12 Vet. App. 119 (1999); Hart v. Mansfield, 21 Vet. App. 505 (2008). 2. Entitlement to a 20 percent rating for lumbosacral strain with degenerative arthritis prior to July 3, 2018 The Veteran is seeking a rating in excess of 10 percent for his back disability, pursuant to DC 5237, prior to July 3, 2018. In the April 2020 Board decision, the Board noted Veteran testified to a worsening of his service-connected back condition since his last VA examination in July 2018. Further, the Veteran testified that he was taking pain medication during the time of the July 2018 examination to treat his service-connected back and right lower and left lower extremity. The claim was remanded for an updated VA examination. Following a November 2020 VA back examination, the Veteran was granted a 40 percent rating for his back disability, effective November 6, 2020. See February 2021 Rating Decision. In an August 2021 rating decision, the 40 percent evaluation for the back was granted an earlier effective date of July 3, 2018. Under 38 C.F.R. § 4.71a, Diagnostic Codes 5235 to 5243, spine disorders are to be rated under the General Rating Formula for Diseases and Injuries of the Spine on the basis of limitation of motion. Under these diagnostic codes, a 10 percent rating is assigned when rating forward flexion of the thoracolumbar spine is greater than 60 degrees but not greater than 85 degrees; or, combined range of motion of the thoracolumbar spine greater than 120 degrees but not greater than 235 degrees; or, muscle spasm, guarding, or localized tenderness not resulting in abnormal gait or abnormal spinal contour; or, vertebral body fracture with loss of 50 percent or more of the height. A 20 percent rating is assigned when forward flexion of the thoracolumbar spine is greater than 30 degrees, but not greater than 60 degrees; when the combined range of motion of the thoracolumbar spine is not greater than 120 degrees; or when there is muscle spasm or guarding severe enough to result in an abnormal gait or abnormal spinal contour such as scoliosis, reversed lordosis, or abnormal kyphosis. A 40 percent rating is assigned when forward flexion of the thoracolumbar spine is 30 degrees or less, or there is favorable ankylosis of the entire thoracolumbar spine. A 50 percent rating is assigned when there is unfavorable ankylosis of the thoracolumbar spine only. Finally, a 100 percent rating is assigned when there is unfavorable ankylosis of the entire spine. The General Rating Formula for Diseases and Injuries of the Spine provides further guidance in rating diseases or injuries of the spine. In pertinent part, Note (1) provides that any associated objective neurologic abnormalities, including, but not limited to, bowel or bladder impairment, should be rated separately under an appropriate diagnostic code. Note (2) provides that, for VA compensation purposes, normal forward flexion of the thoracolumbar spine is zero to 90 degrees, extension is zero to 30 degrees, left and right lateral flexion are zero to 30 degrees, and left and right lateral rotation are zero to 30 degrees. The combined range of motion refers to the sum of the range of forward flexion, extension, left and right lateral flexion, and left and right rotation. The normal combined range of motion of the thoracolumbar spine is 240 degrees. The normal ranges of motion for each component of spinal motion provided in this note are the maximum that can be used for calculation of the combined range of motion. See also Plate V, 38 C.F.R. § 4.71a. Otherwise, disabilities of the spine are rated according to the number of incapacitating episodes a person has had in the past 12 months. An incapacitating episode is a period of acute signs and symptoms due to IVDS that requires bed rest prescribed by a physician and treatment by a physician. See Note (1) to Diagnostic Code 5243. Under the formula, a 10 percent rating is assigned for incapacitating episodes having a total duration of at least one week but less than 2 weeks during the past 12 month period, a 20 percent rating is assigned for incapacitating episodes having a total duration between 2 to 4 weeks during the past 12 month period, a 40 percent rating is assigned for incapacitating episodes having a total duration between 4 to 6 weeks during the past 12 month period, and a 60 percent rating is assigned for incapacitating episodes having a total duration of at least 6 weeks during the past 12 months. 38 C.F.R. § 4.71a, Diagnostic Code 5243, Formula for Rating Intervertebral Disc Syndrome Based on Incapacitating Episodes. Note (1) to Diagnostic Code 5243 provides that, for purposes of ratings under Diagnostic Code 5243, an incapacitating episode is a period of acute signs and symptoms due to intervertebral disc syndrome that requires bed rest prescribed by a physician and treatment by a physician. In addition to considering the orthopedic manifestations of a lumbar spine disability, VA regulations also require that consideration be given to any associated objective neurologic abnormalities, which are to be evaluated separately under an appropriate diagnostic code. Under the revised regulations, effective February 7, 2021, DC 5243 is to be assigned only when there is disc herniation with compression and/or irritation of the adjacent nerve root; assign diagnostic code 5242 for all other disc diagnoses. As the Veteran's back diagnoses do not include disc herniation with compression and/or irritation of the adjacent nerve root (IVDS), DC 5243 will not be applied to adjudicate the claim. Prior to July 3, 2018, the Veteran was afforded a VA examination for his back in February 2012. He was diagnosed with lumbar sprain and reported flare-ups that slowed him down required sitting and resting. The range of motion testing showed Veteran's forward flexion was noted at 0 to 55 degrees, with painful motion. The Veteran was able to perform repetitive-use testing with forward flexion ending at 50 degrees, and he experienced additional limitation of ROM following testing and reported functional loss of the back. The examiner did not offer estimated range of motion during a flare-up, did not specify if there was guarding or muscle spasms, but no muscle atrophy was noted. The Veteran had IVDS but did not have any incapacitating episodes during the prior 12 months. He also required constant use of a cane to assist his back. Service connection is in effect for the Veteran's back disability since July 2009. The Board finds that a 20 percent rating is warranted for the Veteran's back disability since that time. In Sharp v. Shulkin, 29 Vet. App. 26 (2017), the Court held that before a VA examiner opines that he or she cannot offer an opinion as to additional functional loss during flare-ups without resorting to speculation based on the fact that the examination was not performed during a flare, the examiner must "elicit relevant information as to the veteran's flares or ask her to describe the additional functional loss, if any, she suffered during flares and then estimate the veteran's functional loss due to flares based on all the evidence of record, including the veteran's lay information, or explain why she could not do so." Here, the Board finds that the February 2012 VA examination for the Veteran's back disability did not comply with addressing the impact of flare-ups on range of motion of the Veteran's back, pursuant to Mitchell v. Shinseki, 25 Vet. App. 32 (2011) and with Sharp. Therefore, this examination is deemed inadequate. Based on the medical records and evidence provided in Veteran's claims file, the inadequacy of the VA examinations provided because they are not Sharp compliant, and the lay testimony of taking pain medication, deterioration of back pain and continuing increase of functional loss during flare-ups and with repeated use over time, the Board finds that the Veteran's back disability more nearly approximates forward flexion of the thoracolumbar spine greater than 30 degrees but not greater than 60 degrees prior to July 3, 2018. Thus, resolving all doubt in favor of the Veteran, the Board finds that a rating of 20 percent for his back disability is warranted from July 2, 2009 to July 3, 2018. 3. Entitlement to a rating in excess of 40 percent for lumbosacral strain with degenerative arthritis from July 3, 2018 The Veteran is seeking a rating in excess of 40 percent for his back disability, pursuant to DC 5237, from July 3, 2018. In the April 2020 Board decision, the Board noted Veteran testified to a worsening of his service-connected back condition since his last VA examination in July 2018. Further, the Veteran testified that he was taking pain medication during the time of the July 2018 examination to treat his service-connected back and right lower and left lower extremity. The claim was remanded for an updated VA examination. Following a November 2020 VA back examination, the Veteran was granted a 40 percent rating for his back disability, effective November 6, 2020. See February 2021 Rating Decision. In an August 2021 rating decision, the 40 percent evaluation for the back was granted an earlier effective date of July 3, 2018. The Veteran was afforded a VA back examination in July 2018, in which he was diagnosed with lumbosacral strain with degenerative arthritis, reported taking pain medication and did not report flare-ups of the back. He reported functional impairments such as not being able to bend, squat or lift and having trouble with daily tasks such as bathing, and cleaning the house. Forward flexion on initial range of motion was noted at 0 to 70 degrees, with evidence on pain with weight-bearing and no objective evidence of localized tenderness. Veteran performed repetitive-use testing with no additional loss of function or range of motion noted. The Veteran was also examined immediately after repetitive use over time and pain, weakness or fatigability did not significantly limit functional ability. Veteran did not have muscle spasms but was noted to have guarding resulting in abnormal gait. There was no muscle atrophy and no ankylosis of the spine. Veteran did not have IVDS. He required constant use of a cane. See July 2018 C&P Exam. The Veteran was afforded a post-remand VA examination for his back disability in November 2020. The Veteran reported at his VA examination that he continues to take pain medication, and reported flare-ups of the back that were severe, precipitated by movement. He reported having functional impairment of the back in the form of pain when bending, reaching and walking. Forward flexion on initial range of motion testing was noted 0 to 20 degrees, while during flare-ups limitation of motion was estimated at 0 to 15 degrees. Veteran was not able to perform repetitive-use testing and was not examined immediately after repetitive use over time. There was no evidence of guarding or muscle spasms. There was no muscle atrophy. There was no ankylosis of the spine noted. Veteran continued to require constant use of a cane for his back. The Board finds that the results of the July 2018 and November 2020 VA examinations are consistent with a 40 percent rating for the back, pursuant to DC 5237. The Veteran is currently receiving the 40 percent evaluation. The evidence, however, shows that the Veteran does not have ankylosis of the entire thoracolumbar spine or the entire spine. Moreover, the preponderance of the evidence shows that his back disability is not productive of functional equivalent of ankylosis during flare-ups. See Chavis v. McDonough, 34 Vet. App. 1 (2021). As such, a rating of 40 percent, and no more, is warranted from July 3, 2018. Moreover, the Veteran does not contend, and the evidence does not show that his back disability has been manifested by incapacitating episodes having a total duration of at least six weeks, during the past 12 months. As such, the preponderance of the evidence is against a rating in excess of 40 percent. 4. Entitlement to a rating in excess of 10 percent for left lower extremity diabetic neuropathy prior to January 3, 2020 5. Entitlement to a rating in excess of 20 percent for left lower extremity diabetic neuropathy from January 3, 2020 6. Entitlement to a rating in excess of 10 percent for right lower extremity diabetic neuropathy prior to January 3, 2020 7. Entitlement to a rating in excess of 20 percent for right lower extremity diabetic neuropathy from January 3, 2020 The Veteran seeks an increased rating for his service-connected bilateral lower extremity diabetic neuropathy. The bilateral lower extremity neuropathy has been rated at 10 percent disabling since July 2, 2009. Following a remand of the claims in the April 2020 Board decision, the disabilities were granted an increased rating to 20 percent disabling, effective January 3, 2020, pursuant to DC 8520. DC 8520 provides a 10 percent rating for mild incomplete paralysis of the sciatic nerve in either lower extremity; a 20 percent rating for moderate incomplete paralysis of the sciatic nerve; a 40 percent rating for moderately severe incomplete paralysis of the sciatic nerve; a 60 percent rating for severe incomplete paralysis of the sciatic nerve with marked muscular atrophy; and a maximum 80 percent rating for complete paralysis of the sciatic nerve that is characterized by a foot that dangles and drops, no active movement possible of muscles below the knee, and flexion of the knee that is weakened or lost. 38 C.F.R. § 4.124a defines the term "incomplete paralysis" as indicating a degree of lost or impaired function substantially less than the type pictured for complete paralysis given with 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. § 4.123 provides that neuritis, characterized by loss of reflexes, muscle atrophy, sensory disturbances, and constant pain, at times excruciating, is to be rated on the scale provided for injury of the nerve involved, with a maximum equal to severe, incomplete, paralysis. The maximum rating which may be assigned for neuritis not characterized by organic changes referred to in this section will be that for moderate, or with sciatic nerve involvement, for moderately severe, incomplete paralysis. 38 C.F.R. § 4.124 provides that neuralgia, characterized usually by a dull and intermittent pain, of typical distribution so as to identify the nerve, is to be rated on the same scale, with a maximum equal to moderate incomplete paralysis. Tic douloureux, or trifacial neuralgia, may be rated up to complete paralysis of the affected nerve. The words "slight," "moderate" and "severe" as used in the various diagnostic codes are not defined in the VA Schedule for Rating Disabilities. 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. It should also be noted that use of terminology such as "severe" by VA examiners and others, although an element of evidence to be considered by the Board, is not dispositive of an issue. All evidence must be evaluated in arriving at a decision regarding an increased rating. 38 C.F.R. §§ 4.2, 4.6. Prior to January 3, 2020, the Veteran was afforded VA examinations for his back disability and associated neurologic manifestations in February 2012 and in July 2018. During the February 2012 VA back examination, the Veteran was noted to have mild left lower extremity radiculopathy and did not have radiculopathy in the right lower extremity. Subsequently, in the July 2018 VA back examination, the Veteran exhibited moderate intermittent pain, severe paresthesias/dysesthesias, and severe numbness in the right lower extremity; the severity of the right lower extremity was noted as mild while the left lower extremity was not affected. Therefore, the preponderance of the evidence showed that the Veteran's bilateral lower extremity diabetic neuropathy does not warrant a rating in excess of 10 percent prior to January 3, 2020. For the period since January 3, 2020, the Veteran has been rated at 20 percent disabling for his bilateral lower extremity diabetic neuropathy. See May 2020 Rating Decision. The Veteran was afforded a VA Diabetic Neuropathy examination in January 2020, in which he was documented to have mild lower extremity intermittent pain, mild lower extremity paresthesias/dysesthesias, and mild lower extremity numbness. The VA examiner indicated that the severity of the lower extremity diabetic neuropathy was mild for lower extremities. No other neurologic abnormalities or findings related to the back disability were found. Veteran was provided another VA Diabetic Neuropathy examination in November 2020, in which he was documented to have severe lower extremity constant pain, no intermittent pain, moderate lower extremity paresthesias/dysesthesias, and moderate lower extremity numbness. The VA examiner indicated that the severity of the lower extremity diabetic neuropathy was mild for lower extremities. No other neurologic abnormalities or findings related to the back disability were found. The Veteran was also given a VA Back examination in November 2020. The Veteran was noted to have moderate left lower extremity radiculopathy and his right lower extremity was noted to be not affected. See November 2020 C&P Exam. In light of the above, a higher rating for the right and left lower extremities under DC 8520 is not warranted since January 3, 2020, because moderately severe incomplete paralysis and severe incomplete paralysis of the sciatic nerve were not shown. Therefore, the Board concludes that the evidence does not warrant ratings in excess of 20 percent from January 3, 2020, as the Veteran's radicular symptoms do not rise to the level of moderately severe. 8. A total disability rating based on individual unemployability due to service-connected disabilities (TDIU) The Veteran asserts his service-connected disabilities prevent him from securing or following any substantially gainful employment. See February 2020 Hearing Transcript. At the hearing, the Veteran raised a claim for TDIU pursuant to Rice v. Shinseki, 22 Vet. App. 447 (2009). In the April 2020 Board decision, the claim was remanded due to being inextricably intertwined with the other pending claims. The November 2020 VA back, sleep apnea and diabetic neuropathy examinations show that the Veteran's back and associated radiculopathy conditions as well as his OSA impact his ability to work due to limitations on lifting capacity, carrying weight and walking, standing, bending or twisting for extended periods of time. His OSA causes daytime sleepiness caused him to "doze off" so Veteran avoids sitting for long periods of time. Veteran's back condition impacts walking and standing for more than 30 minutes, and also limits pulling, lifting, carrying greater than 15 lbs., and prevents him from working in a sedentary environment without allotted time for scheduled break or in positions that require back rotation due to back pain, numbness and tingling in both legs. See November 2020 C&P Examinations. A total disability rating may be assigned, where the schedular rating is less than total, when it is found that the disabled person is unable to secure or follow a substantially gainful occupation as the result of service-connected disabilities. See 38 U.S.C. § 1155; 38 C.F.R. §§ 3.340, 3.341, 4.16. Consideration may be given to a Veteran's level of education, special training, and previous work experience in arriving at a conclusion, but not to his age or the impairment caused by nonservice-connected disabilities. See 38 C.F.R. §§ 3.341, 4.16, 4.19. To qualify for a total rating for compensation purposes, the evidence must show: (1) a single disability rated as 100 percent disabling; or (2) that the veteran is unable to secure or follow a substantially gainful occupation as a result of his service-connected disabilities and there is one disability ratable at 60 percent or more, or, if more than one disability, at least one disability ratable at 40 percent or more and a combined disability rating of 70 percent. 38 C.F.R. § 4.16(a). For the purpose of establishing one 60 percent disability, or one 40 percent disability in combination, disabilities affecting a single body system are considered as one disability. Id. Disabilities that are not service connected cannot serve as a basis for a total disability rating. 38 C.F.R. §§ 3.341, 4.19. Unlike the regular disability rating schedule, which is based on the average work-related impairment caused by a disability, "entitlement to a TDIU is based on an individual's particular circumstances." Rice v. Shinseki, 22 Vet. App. 447, 452 (2009). Therefore, in adjudicating a TDIU claim, VA must take into account the individual Veteran's education, training, and work history. Hatlestad v. Derwinski, 1 Vet. App. 164 (1991) (level of education is a factor in deciding employability); see Friscia v. Brown, 7 Vet. App. 294 (1994) (considering Veteran's experience as a pilot, his training in business administration and computer programming, and his history of obtaining and losing 19 jobs in the previous 18 years); Beaty v. Brown, 6 Vet. App. 532 (1994) (considering Veteran's 8th grade education and sole occupation as a farmer); Moore v. Derwinski, 1 Vet. App. 356 (1991) (considering Veteran's master's degree in education and his part-time work as a tutor). In determining whether a veteran can secure and follow a substantially gainful occupation, attention must be given to: The veteran's history, education, skill, and training; Whether the veteran has the physical ability (both exertional and non-exertional) to perform the type of activities (e.g., sedentary, light, medium, heavy, or very heavy) required by the occupation at issue. Factors that may be relevant include, but are not limited to, the veteran's limitations, if any, concerning lifting, bending, sitting, standing, walking, climbing, grasping, typing, and reaching, as well as auditory and visual limitations; and Whether the veteran has the mental ability to perform the activities required by the occupation at issue. Factors that may be relevant include, but are not limited to, the veteran's limitations, if any, concerning memory, concentration, ability to adapt to change, handle workplace stress, get along with coworkers, and demonstrate reliability and productivity. Ray v. Wilkie, 31 Vet. App. 58 (2019). The Veteran submitted a VA Form 21-8940, Veteran's Application for Increased Compensation Based on Unemployability, in connection with his TDIU claim in February 2021. The Veteran noted his service-connected musculoskeletal conditions, as well as his service-connected depressive disorder prevented him from following or securing any substantially gainful occupation. He stated he last worked full-time on December 27, 2019, when he became too disabled to work. He was performing maintenance work full-time from February 2019 through December 2019. Prior to his last occupation, he was a substitute teacher working part-time from May 2017 through December 2018. Veteran noted he had a college degree and completed HVAC training in May 2017. The Veteran's service-connected disabilities consist of the following: psychiatric disability at 70 percent disabling, back disability at 40 percent disabling, diabetes mellitus type II at 20 percent disabling, right lower extremity neuropathy at 20 percent disabling, left lower extremity neuropathy at 20 percent disabling, right wrist fracture at 10 percent disabling, hypertension at 10 percent disabling, tinnitus at 10 percent disabling, and tinea pedis at 0 percent disabling. The Veteran's combined evaluation for compensation is 90 percent. Thus, the Veteran meets the threshold schedular requirement for an award of TDIU benefits under 38 C.F.R. § 4.16 (a). The Board notes that the United States Court of Appeals for the Federal Circuit (Federal Circuit) held that determination of whether a Veteran is unable to secure or follow a substantially gainful occupation due to service-connected disabilities is a factual rather than a medical question and that it is an adjudicative determination properly made by the Board or the RO. See Geib v. Shinseki, 733 F.3d 1350 (Fed. Cir. 2013). After a review of the evidence of record, the Board finds, resolving any reasonable doubt as mandated by law (38 U.S.C. § 5107; 38 C.F.R. § 3.102), that the evidence supports that the Veteran's service-connected disabilities prevents him from securing or following substantially gainful employment. As the Veteran meets the requirements under 38 C.F.R. § 4.16(a), is not currently working, and the evidence supports that the Veteran's service-connected disabilities prevent him from securing or following substantially gainful employment, the Board finds that entitlement to a TDIU is warranted. EVEN D. REISS Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Zarar Ahmed, Attorney Advisor 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.