Citation Nr: 21069202 Decision Date: 11/17/21 Archive Date: 11/17/21 DOCKET NO. 15-15 461 DATE: November 17, 2021 ORDER Entitlement to service connection for hypertension (HTN), to include as due to herbicide exposure and/or service-connected disabilities, is denied. Entitlement to service connection for cerebrovascular accident (CVA) or stroke, to include as due to herbicide exposure and/or service-connected disabilities, is denied. Entitlement to special monthly compensation (SMC) based on housebound is denied. Entitlement to SMC based on the need for aid and attendance is denied. FINDINGS OF FACT 1. The Veteran's HTN did not have its onset during active service, did not manifest within one year of separation from active service, and is not secondary to a service-connected disability. 2. The Veteran's CVA/stroke was not present in service, is not shown to be etiologically related to service, and is not secondary to a service-connected disability. 3. The Veteran was not rated at 60 percent disabling for a service-connected disability, in addition to another service-connected disability rated at 100 percent disabling, and it has not been shown that he was in need of regular aid and attendance of another person and/or was housebound as a result of his service-connected disabilities. CONCLUSIONS OF LAW 1. The criteria for entitlement to service connection for HTN have not been met. 38 U.S.C. §§ 1101, 1110, 1113, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. 2. The criteria for service connection for CVA/stroke have not been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. 3. The criteria for SMC based on the need for aid and attendance/housebound status have not been met. 38 U.S.C. § 5110; 38 C.F.R. §§ 3.350, 3.352. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from October 1972 to September 1974. The Veteran died on August [REDACTED], 2016. The appellant is the Veteran's surviving spouse. In February 2020, the appellant testified before the undersigned Veterans Law Judge (VLJ). A transcript of the hearing is of record. In April 2020, February 2021, and July 2021, the Board remanded the claims for further development. Service Connection Generally, service connection will be granted if the evidence shows that a current disability resulted from an injury or disease incurred in or aggravated by active military service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303(a). Service connection is generally established where there is an evidentiary showing of three essential elements: (1) a current disability; (2) in-service incurrence or aggravation of a disease or injury; and, (3) a causal relationship, i.e., a nexus, between the claimed in-service disease or injury and the current disability. Shedden v. Principi, 381 F.3d 1163 (Fed. Cir. 2004). Service connection for certain listed chronic diseases, such as HTN, may be awarded on a presumptive basis and will be presumed to have been incurred during active service, even though there is no evidence of the disability during service, if such disability became manifest to a compensable degree within one year of separation from active duty. That presumption is rebuttable by affirmative evidence to the contrary. 38 U.S.C. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309(a). An alternative method of establishing the second and third elements of service connection for those disabilities identified as a "chronic condition" under 38 C.F.R. § 3.309(a) is through an evidentiary showing of continuity of symptomatology. See Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013); Barr v. Nicholson, 21 Vet. App. 303, 307 (2007). A claimant can establish continuity of symptomatology with competent evidence showing: (1) that a condition was "noted" during service; (2) post-service continuity of the same symptomatology; and (3) a nexus between a current disability and the post-service symptomatology. 38 C.F.R. § 3.303(b). Service connection may also be established for any disability which is proximately due to or the result of a service-connected disease or injury. See 38 C.F.R. § 3.310. In order to prevail on the issue of entitlement to secondary service connection, there must be (1) evidence of a current disability; (2) evidence of a service-connected disability; and (3) nexus evidence establishing a connection between the service-connected disability and the current disability. See Wallin v. West, 11 Vet. App. 509, 512 (1998). Service connection may also be granted for a disease that was first diagnosed after discharge when all of the evidence, including that pertinent to service, establishes that the disease was incurred during service. 38 C.F.R. § 3.303(d). In determining whether service connection is warranted for a disability, VA is responsible for determining whether the evidence supports the claim or is in relative equipoise, with the veteran prevailing in either event, or alternatively, whether a preponderance of the evidence is against the claim, in which case the claim is denied. Gilbert v. Derwinski, 1 Vet. App. 49 (1990); 38 U.S.C. § 5107(b). 1. Entitlement to service connection for HTN Cardiovascular diseases, such as HTN, are considered "chronic" and, therefore, will be presumed to have been incurred in service if manifested to a compensable degree of 10 percent or more within one year of a Veteran's separation from service. This presumption is rebuttable by probative evidence to the contrary. 38 U.S.C. §§ 1101, 1112, 1113, 1137; 38 C.F.R. §§ 3.307, 3.309(a). For VA compensation purposes, the term hypertension means that the diastolic blood pressure is predominantly 90 or greater; and isolated systolic hypertension means that the systolic blood pressure is predominantly 160 or greater with diastolic blood pressure less than 90. 38 C.F.R. § 4.104, DC 7101. Under this code, service connection for pre-hypertension is not warranted when an examiner diagnoses pre-hypertension based on readings not recognized in DC 7101. See VA Adjudication Procedures Manual, M21-MR, III.iv.4.E.20.33. Analysis The appellant contends that that the Veteran's HTN was due to military service to include as due to herbicide exposure, or in the alternative, secondary to his service-connected disabilities. The Veteran has a diagnosis of HTN. As such, element one under Shedden and Wallin is met. Regarding secondary service connection, the Veteran is service connected for diabetes mellitus type II (DM II), posttraumatic stress disorder (PTSD), and a heart condition. As such, element two under Wallin is met. The Veteran's service treatment records (STRs) do not document treatments, complaints, or diagnosis of HTN. On his September 1974 Report of Medical History: Separation exam, the Veteran's blood pressure (BP) reading was 140/76. During his April 1976 (illegible) exam, the Veteran's vascular system was clinically normal. His BP reading was 142/70. The Veteran noted that he did not experience high or low blood pressure. During his RAD exam, his BP reading was 118/74, and during his May 1978 Reserves Enlistment Exam, the Veteran's BP reading was 124/86. He noted that he did not have high or low BP. Post-service, the Veteran was seen at a private medical facility. The Veteran's past medical history noted HTN in September 2002. In October 2020, the agency of original jurisdiction (AOJ) obtained a medical opinion to determine the nature and etiology of the Veteran's HTN. The examiner confirmed the Veteran's HTN diagnosis. The examiner opined that the Veteran's HTN was less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness. The examiner stated that the Veteran's STRs do not document diagnosis or treatment for HTN. The Veteran's post service medical records show that he was diagnosed with essential or primary chronic HTN and started on antihypertensive medications in September 2002, i.e., 25 years after retirement. The examiner stated that the Veteran's HTN was not established during military service or within a year of separation. Regarding agent orange (AO) exposure and the Veteran's development of HTN, the examiner stated that the Veteran was diagnosed with HTN in 2002, at age 50, with other strong risk factors for HTN. The examiner stated that the Evidence Based Medical Literature (EBML) shows that "the global prevalence of hypertension is high, and among nonpregnant adults in the United States, treatment of hypertension is the most common reason for office visits and for the use of chronic prescription medications." "The pathogenesis of primary hypertension (formerly called "essential" hypertension) is poorly understood but is most likely the result of numerous genetic and environmental factors that have multiple compounding effects on cardiovascular and renal structure and function." The examiner also noted, "A number of risk factors are strongly and independently associated with its development, including age, obesity, family history, race, reduced nephrohe condition claimed was less likely than not incurred in or caused by the claimed in-service injury, event, or illness. n number, High-sodium diet, excessive alcohol consumption, physical inactivity." "Secondary causes of HTN are multiple (prescription and illicit drugs, primary renal diseases, primary aldosteronism, renovascular HTN, several endocrine disorders and coarctation of the aorta." The November 2018 National Academies of Science, Engineering and Medicine Update 11 (2018) addresses whether there is an association between exposure to an herbicide agent and hypertension. The committee believes that there are enough new data to move the category of association to sufficient evidence. The reference study was a cohort study published in 2016 that looked at self-reported physician-diagnosed-hypertension in Army Chemical Corps veterans who sprayed defoliant in Vietnam. The study concluded that occupational herbicide exposure history and Vietnam-service-status were significantly associated with hypertension risk. The examiner stated that while this study reported an association between hypertension and AO, there is no current evidence of AO causing hypertension; association does not mean causation. In formulating the medical opinion, the examiner referred to the AO Act of 1991 by Congress, and stated that until further official guidance as to HTN being added on the list of presumed conditions, and without finding in the literature a causative relationship between HTN and exposure to AO, the condition claimed was less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness. The examiner also opined that the Veteran's HTN is less likely than not, proximately due to, or the result of the Veteran's service-connected condition. The Veteran's DM II was diagnosed in 2010, eight years after his HTN diagnosis; therefore, his DM II cannot have caused his HTN. The Veteran's records show that, over the years, the Veteran's HTN was controlled with antihypertensive medications and has had a stable natural course/history of this condition. There is no evidence that DM II has aggravated his chronic HTN. The Veteran also has a history of hyperlipidemia, obesity, was a heavy smoker, and had a family history of coronary artery disease (CAD). He presented to the ER on September 3, 2002 for new onset of CP. He had a stress echo and a left cath and was diagnosed with diffuse non obstructive CAD. A repeat nuclear stress test was done in December 2010 and was normal, there was no worsening of his ischemic heart disease (IHD). The Veteran's IHD and HTN were simultaneously diagnosed, share a few risk factors, and can be seen in association in a same patient. However, there is no medical evidence of a causative effect between the two conditions. The examiner stated that association does not mean causation. The Veteran's IHD/CAD has not caused HTN, and has not aggravated his HTN which, since the diagnosis, had been well controlled on antihypertensives. The examiner further stated that research evidence suggests that PTSD can be associated with a range of physical health conditions including HTN. However, this Veteran's HTN is primary/essential, with multiple strong risk factors for its development (age, hyperlipoproteinemia (HLP), tobacco smoking, obesity, family history). Furthermore, the examiner was unable to find any evidence in the EBML of a causative effect between the two conditions. The examiner stated that the Veteran's HTN had been well controlled over the years, and its course had not been affected by his service-connected PTSD. The examiner stated that PTSD had not caused HTN and had not aggravated the Veteran's HTN which had been well controlled since diagnosis. In February 2021, the Board noted that the October 2020 medical examiner opined it was less likely than not that the Veteran's HTN was related to his active duty service to include exposure to herbicides. The Board noted that while the examiner listed relevant HTN risk factors, the examiner did not provide specific rationale on how the listed risk factors specifically applied to the facts of the Veteran's case. Additionally, the examiner discussed secondary service connection and noted the Veteran had a history of hyperlipidemia, obesity, smoking, and family history risk factors; however, there was no discussion on whether these applied to or specifically affected the Veteran's HTN. The Board found the exam inadequate and remanded the claim for a new opinion. In April 2021, the AOJ obtained another medical opinion to determine the nature and etiology of the Veteran's HTN. The examiner reviewed all available medical records in VBMS, CPRS, CAPRI, JLV, the hearing transcript, the April 2020 remand, and the more recent remand requesting specific clarifications. The examiner also reviewed the EBML and again was unable to find any report of causality between HTN and AO. The examiner reread the November 2018, National Academies of Science, Engineering and Medicine Update 11 (2018) that addresses whether there is an association between exposure to an herbicide agent and HTN. The examiner stated that the committee for the update believed that there are enough new data to move the category of association to sufficient evidence. However, at that time, the committee was not considering a causal relationship between AO and HTN. The examiner noted that association is "NOT" causation, and until causality is established by the scientific community and Congress lists it as a presumptive condition along others, the examiner stood by the previous October 27, 2020, conclusion that the condition claimed was less likely than not incurred in or caused by the claimed in-service injury, event or illness. Regarding whether the Veteran's HTN was aggravated by his service-connected DM II, the examiner stated, as noted in the previous medical opinion, this Veteran's DM II was diagnosed in 2010, eight years after his HTN diagnosis, and therefore, could not have caused his HTN. Regarding possible aggravation of HTN by service-connected DM II, the records show that, over the years, his BP was controlled with antihypertensive medications, and his HTN has had a stable course/history. After his DM II diagnosis, there was no evidence of worsening of HTN beyond its natural history, and the course has been stable. The examiner stated that there was no evidence that DM II aggravated the Veteran's chronic HTN. Regarding whether the current severity of the HTN was greater than the baseline, the examiner stated that the records show that after his 2010 DM II diagnosis, the Veteran's BP kept stable for years, well controlled on the same medications. In August 2016, the Veteran's BP started to become erratic, due to multiple associated factors and comorbidities, independent of his DM II. After reviewing the EBML on the topics of HTN, DM II, and their correlations, the examiner was unable to find any evidence that DM II aggravated HTN. The examiner also stated that the records showed that the Veteran's HTN and IHD were diagnosed simultaneously in September 2002. The examiner further stated that there is no evidence in the literature that IHD aggravates HTN. In July 2021, the Board noted that the AOJ obtained an addendum opinion in April 2021. The Board stated that the April examiner stood by the findings made in the October 2020 VA opinion. However, the April examiner did not address or explain the October 2020 listing of risk factors of HTN and whether or not they applied to the specific facts of the Veteran's case. The Board remanded the claim for another opinion. In August 2021, the AOJ obtained another medical opinion to determine the nature and etiology of the Veteran's HTN. The examiner opined that the claimed condition was less likely than not (less than 50 percent probability) incurred in or caused by the claimed in-service injury, event, or illness. The examiner stated that it is unclear when the Veteran was actually diagnosed with HTN. The Veteran did not have HTN as late as May 7, 1978. The examiner stated that there is no evidence of HTN while in service, and there is no evidence of HTN within one year of service. At the time of his separation exam, the Veteran's systolic BP was slightly elevated at 140/76 at the time of separation. During his April 4, 1976 periodic exam, the Veteran's BP was normal, and his June 7, 1978 BP was 112/74. Therefore, it is less likely than not that the Veteran's HTN had its nexus in service or was due to events in service, to include exposure to AO. Further, AO has not been shown to cause HTN. The examiner stated that the 2018 NAS study did not establish AO as a cause of HTN. It suggested a possible association but did not establish cause. A review of the current, widely accepted, peer-reviewed literature, including Up to Date, a respected professional medical resource wherein one may access current professional treatises and studies, failed to return articles establishing AO as a cause of HTN. In summary, it is less likely than not that the Veteran's HTN had its nexus in service or was due to AO exposure. The examiner also opined that the Veteran's HTN is less likely than not proximately due to or the result of Veteran's service-connected disabilities. The examiner noted that he had no list of the Veteran's service-connected conditions. However, from the rating decisions, it appeared that the Veteran's service-connected disabilities included DM II, heart conditions, and PTSD. The examiner stated that there is no evidence of aggravation of the Veteran's HTN beyond its natural course due to any cause. The natural course of the condition tends to progress, often requiring medication changes and adjustments. PTSD has not been shown to cause HTN nor does it aggravate it. The current, widely accepted peer-reviewed literature has not established PTSD and related psychological comorbidities, including anxiety, depression, panic disorders, etc. as a cause of essential HTN. By definition, essential HTN is not caused by any other condition. The examiner noted that Up to Date, a respected professional medical resource wherein one may access current professional treatises and studies, do not include published articles supporting a cause or aggravation link for the psychological conditions and HTN. The article cited above noted a possible association between PTSD, and related psychological comorbidities, and depression but did not establish cause or aggravation. The authors merely concluded that further research with appropriately designed studies is required to determine the relationship between these conditions and HTN. Although anxiety, stress, activity, panic attacks, a startling event, etc. may temporarily elevate one's blood pressure, the elevated BP resolves following the abatement of the stimulus and the autonomic response ("Fight or flight/White coat HTN"). It does not constitute aggravation as it does not impact the baseline condition. The examiner also stated that the Veteran's heart conditions did not cause nor aggravate the Veteran's HTN. High blood pressure is due to increased peripheral vascular resistance and is not related to the heart conditions themselves. (Harrison's and/or Cecil's textbooks of internal medicine). As noted above, there is no evidence of aggravation beyond the natural course due to any cause. Based on the evidence of record, the Board finds that service connection for HTN is not warranted on a direct, presumptive, or secondary basis. The August 2021 VA examiner opined that the Veteran's HTN was less likely than not incurred in or caused by the claimed in-service injury, event, or illness. The examiner stated that it is unclear when the Veteran was actually diagnosed with HTN. However, the Veteran did not have HTN as late as May 7, 1978. During his April 4, 1976 periodic exam, the Veteran's BP was normal, and in June 1978, his BP was 112/74. The examiner noted that although the Veteran's systolic BP was slightly elevated at 140/76 at the time of separation, there is no evidence of HTN within one year of service. Regarding HTN and AO, the examiner stated that AO has not been shown to cause HTN. The 2018 NAS study did not establish AO as a cause of HTN. It suggested a possible association but did not establish cause. A review of the current, widely accepted, peer-reviewed literature, including Up to Date, failed to return articles establishing AO as a cause of HTN. As such, the examiner opined that it is less likely than not that the Veteran's HTN had its nexus in service or was due to events in service, to include exposure to AO. The Board notes that the separation examination BP reading was elevated, i.e., 140/76. However, as noted above, the term HTN means that the diastolic blood pressure is predominantly 90 or greater. 38 C.F.R. § 4.104, DC 7101. In this case, the Veteran's diastolic blood pressure was not predominantly 90 or greater. Additionally, the first medical evidence of HTN was in 2002, i.e., over 28 years after his discharge from active service. The fact that there were no records of any complaints or treatment involving the Veteran's HTN for many years weighs against the claim. See Maxson v. West, 12 Vet. App. 453, 459 (1999), affirmed sub nom. Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000) (it was proper to consider the veteran's entire medical history, including a lengthy period of absence of complaints). Therefore, the Board finds that elements two and three under Shedden have not been met. Regarding presumptive service connection, the record does not show evidence of HTN within one year of the Veteran's separation from active duty. The first competent evidence suggestive of HTN was in 2002, i.e., 28 years after his discharge from service. As there is no competent evidence that the disability manifested to a compensable degree within one year of his active service and was not continuous since service, a presumption of service connection under 38 C.F.R. §§ 3.307, 3.309 is not warranted. Regarding secondary-service connection, the August 2021 examiner opined that the Veteran's HTN is less likely than not proximately due to or the result of the Veteran's service-connected condition. The examiner stated that there is no evidence of aggravation of the Veteran's HTN beyond its natural course due to any cause as the natural course of the condition tends to progress, often requiring medication changes and adjustments. The examiner also stated that PTSD has not been shown to cause or aggravate HTN. The current, widely accepted peer-reviewed literature has not established PTSD and related psychological comorbidities, including anxiety, depression, panic disorders, etc. as a cause of essential HTN. By definition, essential HTN is not caused by any other condition. The examiner noted that Up to Date does not include published articles supporting a cause or aggravation link for the psychological conditions and HTN. The examiner further stated that the article cited above noted a possible association between PTSD, and related psychological comorbidities, and depression but did not establish cause or aggravation. The authors merely concluded that further research with appropriately designed studies is required to determine the relationship between these conditions and HTN. Although anxiety, stress, activity, panic attacks, a startling event, etc. may temporarily elevate one's blood pressure, the elevated BP resolves following the abatement of the stimulus and the autonomic response. The examiner stated that it does not constitute aggravation as it does not impact the baseline condition. Additionally, the Veteran's heart conditions did not cause nor aggravate his HTN. The examiner stated that high blood pressure is due to increased peripheral vascular resistance and is not related to the heart conditions themselves. The examiner stated that there is no evidence of aggravation beyond the natural course due to any cause. The Board has considered the Veteran, the appellant, and the representative's statements regarding the etiology of the Veteran's HTN. The Board notes that although lay persons are competent to provide opinions on some medical issues, see Kahana v. Shinseki, 24 Vet. App. 428, 435 (2011), as to the specific issue in this case, a nexus between the HTN and active service and/or service-connected disabilities, is outside the realm of common knowledge of a lay person. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 n. 4 (Fed. Cir. 2007) (lay persons not competent to diagnose cancer). As there is no medical nexus linking the Veteran's HTN to active service, and/or his service-connected disabilities, the preponderance of the evidence is against the Veteran's claim. The benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107(b). 2. Entitlement to service connection for stroke/CVA The Veteran contends that his stroke is due to military service, to include as due to herbicide exposure, or in the alternative, secondary to his service-connected disabilities. The Veteran has been diagnosed with CVA. As such, element one under Shedden and Wallin is met. As noted above, the Veteran is service connected for DM II, PTSD, and a heart condition. As such, element two under Wallin is met. The Veteran's STRs do not document treatments, complaints, or diagnosis of a stroke/CVA. In July 1972, the Veteran was seen for a cut on his head, contusion, and edema from a head trauma of the forehead. He had a 3/4-inch incision. He was diagnosed with a contusion. The Board notes that the Veteran's available separation exam does not document a head injury or stroke. Additionally, during his April 1976 and May 1978, Report of Medical Examination Reserve exams, the Veteran's head was clinically normal. He denied a head injury. In October 2010, the Veteran saw his private examiner regarding a one month follow up for stroke. In October 2020, the AOJ obtained a medical opinion to determine the nature and etiology of the Veteran's stroke. The examiner confirmed the Veteran's stoke diagnosis. The examiner opined that the Veteran's stroke was less likely than not incurred in or caused by the claimed in-service injury, event, or illness. The Veteran's STRs noted that on July 15, 1972, he was seen for a head laceration after a head contusion. The examiner stated that there is no evidence in the records of any chronic disability from this event. However, on July 22, 2010, 38 years after the in-service trauma event, the Veteran was admitted to Memorial University Hospital for a CVA. His July 2010 brain MRI showed right thalamic lacunar infarct and diffuse small vessel disease. Per UTD, several mechanisms for small vessel disease and lacunar infarctions have been described as direct consequence of systemic HTN. Regarding AO exposure and CVA, the examiner was unable to find any medical evidence linking AO to development of CVA. Additionally, CVA is not on the list of presumed conditions due to exposure to AO. The examiner stated that the Veteran's CVA was due to diffuse small vessel disease is due to his HTN and atheroma deposits from hyperlipidemia on the wall of the cerebral vasculature and not due to exposure to AO. The examiner also opined that the Veteran's CVA is less likely than not proximately due to or the result of the Veteran's service-connected disabilities. The examiner stated that the preponderance of the medical literature does not support DM II, CAD, or PTSD as causes for CVA. CVA is due to acute brain vessel occlusion and/or small vessel disease secondary to embolus from the heart or carotid arteries and/or diffuse atherosclerosis seen with hyperlipidemia. The examiner stated that the Veteran's CVA has not been caused by his service-connected disabilities, merely sharing risk factors for CVA, but without causative relationship. The examiner found no evidence that the Veteran's service-connected conditions aggravated the residuals of his CVA. Based on the evidence of record, the Board finds that service connection for CVA/stroke is not warranted. The Veteran's STRs do not document complaints, treatments, symptoms, or diagnoses for CVA/stroke. Additionally, the October 2020 VA examiner opined that the Veteran's CVA is less likely than not incurred in or caused by the claimed in-service injury, event, or illness. On July 15, 1972, he was seen for a head laceration after a head contusion. However, there is no evidence in the records of any chronic disability from this event. The examiner further stated that the Veteran was admitted to Memorial University Hospital for a CVA he sustained on July 22, 2010, 38 years after the in-service trauma event. The Veteran's July 2010 brain MRI showed right thalamic lacunar infarct and diffuse small vessel disease. The examiner stated that per UTD, several mechanisms for small vessel disease and lacunar infarctions have been described as direct consequence of systemic HTN. Regarding the Veteran's CVA and AO, the examiner was unable to find any medical evidence linking AO to the development of CVA. Additionally, CVA is not on the list of presumed conditions due to exposure to AO. The examiner stated that the Veteran's diffuse small vessel disease is due to his HTN and atheroma deposits from hyperlipidemia on the wall of the cerebral vasculature and not due to exposure to AO. The Board notes that the Veteran is not service connected for either HTN or atheroma deposits from hyperlipidemia. Additionally, the first medical evidence of stroke/CVA was in 2010, i.e., over 36 years after his discharge from active service. The fact that there were no records of any complaints or treatment involving the Veteran's CVA/stroke for many years weighs against the claim. See Maxson v. West, 12 Vet. App. 453, 459 (1999), affirmed sub nom. Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000) (it was proper to consider the veteran's entire medical history, including a lengthy period of absence of complaints). Regarding secondary service connection, the examiner also opined that the Veteran's CVA is less likely than not proximately due to or the result of the Veteran's service-connected disabilities. The examiner stated that the preponderance of the medical literature does not support DM II, CAD, or PTSD as causes for CVA which is due to acute brain vessel occlusion and/or small vessel disease secondary to embolus from the heart or carotid arteries and/or diffuse atherosclerosis seen with hyperlipidemia. The examiner stated that the CVA has not been caused by his service-connected conditions, merely sharing risk factors for CVA, but without causative relationship. The examiner found no evidence that the Veteran's service-connected conditions aggravated the residuals of his CVA. The Board also notes that the examiner attributed the Veteran's CVA to his non-service connected HTN and/or atheroma deposits from hyperlipidemia. As such, the Board finds that elements two and three under Shedden and element three under Wallin have not been met. Therefore, service connection is not warranted. The Board has considered the Veteran, the appellant, and the representative's statements regarding the etiology of the Veteran's CVA/stroke. Although lay persons are competent to provide opinions on some medical issues, see Kahana v. Shinseki, 24 Vet. App. 428, 435 (2011), as to the specific issue in this case, a nexus between the Veteran's CVA/stroke and service, is outside the realm of common knowledge of a lay person. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 n. 4 (Fed. Cir. 2007) (lay persons not competent to diagnose cancer). Additionally, the medical evidence of record does not contain a nexus opinion by a medical professional relating the Veteran's CVA/stroke to his service. In the absence of a nexus, the claim for service connection for CVA/stroke is denied. In reaching the above conclusion, the Board has considered the applicability of the benefit of the doubt doctrine. However, as the preponderance of the evidence is against the Veteran's claim, that doctrine is not applicable in the instant appeal. See Gilbert, 1 Vet. App. at 55-56; 38 U.S.C. § 5107(b). 3. Entitlement to SMC based on aid and attendance and/or housebound status SMC under 38 U.S.C. § 1114(l) is payable where a veteran, as the result of service-connected disability, has suffered the anatomical loss or loss of use of both feet, or of one hand and one foot, or is blind in both eyes, with 5/200 visual acuity or less, or is permanently bedridden or so helpless that he is in need of the regular aid and attendance of another person. 38 C.F.R. § 3.350 (b). In making aid and attendance determinations, consideration is given to such conditions as: inability of the claimant to dress or undress himself or to keep himself ordinarily clean and presentable; frequent need of adjustment of any special prosthetic or orthopedic appliances which, by reason of the particular disability, cannot be done without aid; inability of the claimant to feed himself through loss of coordination of upper extremities or through extreme weakness; inability to attend to the wants of nature; or incapacity, physical or mental, which requires care or assistance on a regular basis to protect the claimant from the hazards or dangers inherent in his daily environment. 38 C.F.R. § 3.352 (a). The above are only factors for consideration, and it is left to the Board to determine whether a veteran is factually in need of regular aid and attendance. The particular personal functions that a veteran is unable to perform are also considered in connection with their condition as a whole. It is only necessary that the evidence establish that a veteran is so helpless as to need regular aid and attendance, not that there be a constant need, however the need must be caused solely by service-connected disabilities. Id.; see also Turco v. Brown, 9 Vet. App. 222 (1996). SMC is also payable at the housebound rate where the Veteran has a single service-connected disability rated as 100 percent and, in addition: (1) has a service-connected disability or disabilities independently ratable at 60 percent, separate and distinct from the 100 percent service-connected disability, and involving different anatomical segments or bodily systems, or (2) is permanently housebound by reason of service-connected disability or disabilities. 38 U.S.C. § 1114(s); 38 C.F.R. § 3.350(i). The requirement of "permanently housebound" status will be considered to have been met when the veteran is substantially confined to his house (or ward or clinical areas, if institutionalized) or immediate premises due to disability or disabilities which it is reasonably certain will remain throughout his lifetime. See 38 U.S.C. § 1502(c); 38 C.F.R. § 3.351(d)(2). Analysis The Veteran sought SMC due to being housebound and needing assistance from others for his daily care. Prior to his death, the Veteran was service connected for PTSD rated at 50 percent disabling, DM II rated at 20 percent disabling, and a heart condition rated at 10 percent disabling. Based on the evidence, the Board notes that the Veteran did not meet the statutory rating requirements for an award of SMC under 38 U.S.C. § 1114(s) as there is no indication that, because of his disabilities, he had an anatomical loss or loss of use of both feet, or of one hand and one foot or had blindness in both eyes with visual acuity of 5/200 or less. See 38 U.S.C. § 1114(l). Additionally, the record does not show that the Veteran was permanently housebound or was so helpless as to require the regular aid and attendance of another person as a result of his service-connected PTSD, DM II, and/or heart condition. The Board notes that during his June 2013 Anesthesia Pre-operative E & M Note, the examiner noted that the Veteran experienced a heatstroke in 2010 that affected his speech and memory. Additionally, the Veteran experienced residual right-side weakness. However, the Veteran walked a quarter mile two times per week, and he cut the grass on a riding lawnmower. From August to October 2014, the Veteran attended and participated in the Savannah Outpatient Clinic, Smoking Cessation group. During his February 2015 PTSD VA examination, the examiner noted that, at home, the Veteran took out the trash and attempted to sweep. Additionally, the Veteran was capable of completing most personal hygiene tasks; however, he needed assistance with dressing (shirt/pants). The examiner stated that the Veteran had a significant change in quality of life; however, this was due to his non-service-connected stroke. Therefore, based on the evidence, the Board finds that the Veteran was not permanently housebound by reason of his service-connected disabilities. Although the evidence of record does show that the Veteran needed assistance with dressing, there is nothing to suggest that this was the result of his service-connected disabilities. As noted above, the February 2015 PTSD VA examiner noted that the Veteran's significant change in quality of life was due to his non-service-connected stroke. The law is clear, however, that SMC under 38 U.S.C. § 1114(l) is payable only when service-connected disabilities render a veteran so helpless as to be in need to aid and attendance of another. In other words, the impact of nonservice-connected disabilities on the Veteran's functional abilities is not for consideration in determining entitlement to SMC based on the need for aid and attendance. Here, the Board finds that the Veteran's service-connected disabilities did not rendered him so helpless as to require the regular aid and attendance of another. Therefore, the Board finds that the preponderance of the evidence is against the claim. As such, SMC based on the need for aid and attendance and/or housebound status is denied. MICHAEL LANE Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Moore, Tara-Deen 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.