Citation Nr: 24012467 Decision Date: 03/18/24 Archive Date: 03/18/24 DOCKET NO. 19-22 826 DATE: March 18, 2024 ORDER Entitlement to service connection for headaches, to include as due to environmental exposures, an undiagnosed illness, a symptom of a medically unexplained chronic multi-symptom illness (MUCMI), and/or secondary to service-connected bilateral restless leg syndrome is denied. FINDING OF FACT The evidence of record persuasively weighs against finding that the Veteran's tension headaches were incurred during active duty service or are otherwise related to an in-service injury or disease, or are a medically unexplained chronic multi-symptom illness, or are secondary to a service-connected disability, or are related to toxic exposure risk activity (TERA). CONCLUSION OF LAW The criteria for headaches have not been met. 38 U.S.C. §§ 1110, 1112, 1131, 1117, 1118, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.317. REASONS AND BASES FOR FINDING AND CONCLUSION The Veteran had active military service from October 1988 to November 1997, to include service in Southwest Asia. He is the recipient of several medals, including a Southwest Asia Service Medal with 2 Bronze Stars, Kuwait Liberation Medal (Saudi Arabia), and a Kuwait Liberation Medal (Kuwait). This matter comes before the Board of Veterans' Appeals (Board) on appeal from a June 2018 rating decision issued by a Department of Veterans Affairs (VA) Regional Office (RO). The Veteran testified before the undersigned Veterans Law Judge during an October 2021 Board hearing. A copy of the transcript has been associated with the file. This matter was previously before the Board in March 2022 and May 2023. In May 2023, the Board remanded for additional development. Lastly, the Board acknowledges that the Veteran filed an original claim seeking compensation for fatigue, muscle pain, joint pain, neurological and respiratory disturbances, stress headaches, and night sweats all as symptoms of an undiagnosed illness. See March 2018 VA Form 21-526EZ. During the pendency of the appeal, the RO has granted service connection for bilateral lower extremity muscle pain, bilateral lower extremity joint pain, bilateral lower extremity restless leg syndrome, obstructive sleep apnea, fatigue, and night sweats. See August 2022 Rating Decision. Applicable Law and Regulations Generally, establishing service connection requires competent evidence of three things: (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, 1167 (Fed. Cir. 2004). Service connection may also be established on a secondary basis when a disability is shown to be 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) caused by or (b) aggravated by a service-connected disability. See Allen v. Brown, 7 Vet. App. 439 (1995). In addition, certain chronic diseases, including an organic disease of the nervous system (including migraine headaches), will be presumed related to service if they were shown as chronic in service or if it manifested to a compensable degree within a presumptive period following separation from service. 38 C.F.R. §§ 3.307, 3.309. If the disease's chronicity was not noted in service, the disability can still be presumed related to service if the evidence shows there is a continuity of symptomatology since service. Walker v. Shinseki, 708 F.3d 1331, 1338. The record reflects the Veteran had qualifying service in Southwest Asia during the Persian Gulf War and, therefore, such laws and regulations are applicable to his claim. Service connection may be granted for a Persian Gulf veteran with a qualifying chronic disability that became manifest to any degree at any time. 38 U.S.C. § 1117(a)(1); 38 C.F.R. § 3.317(a)(1). A qualifying chronic disability means a chronic disability resulting from any of the following (or any combination of the following): undiagnosed illness; the following medically unexplained chronic multi-symptom illnesses (MUCMI) that are defined by a cluster of signs or symptoms: chronic fatigue syndrome; fibromyalgia; functional gastrointestinal disorders (excluding structural gastrointestinal diseases); or any diagnosed illness for which the Secretary determines that presumptive service-connection is warranted; or any other illness for which the Secretary determines that the following criteria for a MUCMI are met. See 38 U.S.C. § 1117; 38 C.F.R. § 3.317(a)(2)(i). The term "medically unexplained chronic multi-symptom illness" means a diagnosed illness without conclusive pathophysiology or etiology, that is characterized by overlapping symptoms and signs and has features such as fatigue, pain, disability out of proportion to physical findings, and inconsistent demonstration of laboratory abnormalities. Chronic multi-symptom illnesses of partially understood etiology and pathophysiology will not be considered medically unexplained. See 38 U.S.C. § 1117; 38 C.F.R. § 3.317(a)(2)(ii). The term "objective indications of chronic disability" includes both "signs," in the medical sense of objective evidence perceptible to an examining physician, and other, non-medical indicators that are capable of independent verification. See 38 U.S.C. § 1117; 38 C.F.R. § 3.317(a)(3). Signs or symptoms which may be manifestations of undiagnosed illness or medically unexplained chronic multi-symptom illness include, but are not limited to: (1) fatigue, (2) unexplained rashes or other dermatological signs or symptoms, (3) headache, (4) muscle pain, (5) joint pain, (6) neurological signs and symptoms, (7) neuropsychological signs or symptoms, (8) signs or symptoms involving the upper or lower respiratory system, (9) sleep disturbances, (10) gastrointestinal signs or symptoms, (11) cardiovascular signs or symptoms, (12) abnormal weight loss, and (13) menstrual disorders. 38 C.F.R. § 3.317(b). The Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics (PACT) Act, was enacted on August 10, 2022. Section 405 of the PACT Act reduces the threshold for establishing eligibility when considering presumptive service connection for Persian Gulf War veterans. Presumptive conditions under 38 C.F.R. § 3.317(a) and (b) may now manifest to any degree at any time. There is no longer a requirement for a chronic disability to manifest to a degree of 10 percent or more prior to December 31, 2026. The end date is no longer applicable and will be removed in a forthcoming regulation. Additionally, the PACT expanded the definition of a Persian Gulf veteran to include those who served in the countries of Afghanistan, Israel, Egypt, Turkey, Syria, and Jordan, along with those who served in the Southwest Asia theater of operations as defined in 38 C.F.R. § 3.317(e). Disabilities that have existed for 6 months or more and disabilities that exhibit intermittent episodes of improvement and worsening over a 6-month period will be considered chronic. The 6-month period of chronicity will be measured from the earliest date on which the pertinent evidence establishes that the signs or symptoms of the disability first became manifest. 38 C.F.R. § 3.317(a)(4). With claims based on undiagnosed illnesses, the veteran is not required to provide competent evidence linking a current disability to an event during service. Gutierrez v. Principi, 19 Vet. App. 1 (2004). There must be no affirmative evidence that relates the undiagnosed illness to a cause other than being in the Southwest Asia Theater of Operations during the Persian Gulf War. 38 C.F.R. § 3.317(c). If signs or symptoms have been attributed to a known clinical diagnosis in the particular veteran's case being considered, service connection may not be provided under the specific provisions pertaining to Persian Gulf Veterans. VAOPGCPREC 8-98 at paras. 4-5 (Aug. 3, 1998). In rendering a decision on appeal, the Board must analyze the credibility and probative value of all medical and lay evidence of record, account for the evidence which it finds to be persuasive or unpersuasive and provide the reasons for its rejection of any material evidence favorable to the claimant. 38 U.S.C. § 1154(a); Buchanan v. Nicholson, 451 F.3d 1331 (Fed. Cir. 2006). Competency of evidence differs from weight and credibility. Competency is a legal concept determining whether testimony may be heard and considered by the trier of fact, while credibility is a factual determination going to the probative value of the evidence to be made after the evidence has been admitted. Rucker v. Brown, 10 Vet. App. 67, 74 (1997); Layno v. Brown, 6 Vet. App. 465, 469 (1994); see also Cartright v. Derwinski, 2 Vet. App. 24, 25 (1991) ("although interest may affect the credibility of testimony, it does not affect competency to testify"). The credibility of a witness can be impeached by a showing of interest, bias, inconsistent statements, the demeanor of the witness, the facial plausibility of the testimony, the internal consistency of the testimony, impairment in memory, or, to a certain extent, bad character, among other factors. Caluza v. Brown, 7 Vet. App. 498, 510-511 (1995), aff'd per curiam, 78 F.3d 604 (Fed. Cir. 1996). In particular, personal interest may affect the credibility of the evidence. Cartright, 2 Vet. App. at 25. When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the Board must resolve reasonable doubt in favor of the Veteran. 38 U.S.C. § 5107; 38 C.F.R. § 3.102. The United States Court of Appeals for the Federal Circuit clarified in Lynch v. McDonough that the proper standard of review is whether the factors are in an "approximate balance." Lynch v. McDonough, 999 F.3d 1391 (2021). Lynch held that the Veteran is entitled to the benefit of the doubt when the evidence is in an approximate balance or "nearly equal" and does not require the evidence to be in exact equipoise. Id. Entitlement to service connection for headaches is denied. The Veteran contends that his headaches had their onset during service and have continued since service. He maintains that his headaches are due to a chronic multi-symptom or undiagnosed illness due to his Gulf War service and/or are secondary to his neurological condition. See March 2018 Statement in Support; March 2018 VA Form 21-526EZ. Background The Veteran's service treatment records (STRs) include a Report of Medical Examination for enlistment in September 1988, with no headache disability noted. On his corresponding Report of Medical History, the Veteran self-reported "no" to frequent or severe headaches. During a March 1990 optometry examination, the Veteran reported headaches with reading fine print (distance no problem). The clinician noted to return to the clinic in one year for a follow up, especially if headaches persisted with reading. In a February 1990 STR he presented with complaints of stuffy nose, sinus pressure, and headaches for 1 day. The diagnosis was a common cold, and he was prescribed Tylenol. Subsequent examinations dated in June 1994, October 1997 (separation from active duty) and December 1997 (enlistment for Reserve service) each reflect clinical examination of the Veteran's neurologic system, as relevant to a headache disability, was normal. On his Report of Medical History in October 1992, June 1994, and October 1997, the Veteran self-reported "no" to frequent or severe headaches. A September 1991 treatment record noted no chronic medical problems, and the Veteran was fit for deployment overseas. During a December 1995 medical certification examination for explosive ordnance drivers, the Veteran reported "no" to headaches, and migraine headaches. On his December 1997 Report of Medical History for enlistment into the Army Reserve, the Veteran self-reported his present health as "good" and responded "no" to frequent or severe headaches. Post-service, on a November 2009 medical history form for private employment, the Veteran did not check "yes" to frequent headaches or migraines. A private treatment record from July 2011 noted the Veteran was seen for a laceration to the top of his right middle finger. A recent history of pneumonia was noted. The Veteran reported fever, fatigue, chest pain, chills, bilateral ear pain, throat pain, sinus pain, and headaches. Diagnoses of open wound to fingers, unspecified otitis media, and bacterial pneumonia were noted. The Veteran was seen for a neurology consultation in September 2017 by a private provider. He denied headaches. The Veteran denied headaches in September 2017, March 2021, June 2023, and July 2023 VA treatment records. He was seen in the emergency room in January 2018 for complaints of a headache with onset 2 days ago and diagnosed with tension headaches. During a March 2018 VA sleep consultation, he reported a history of headaches. He complained of headaches during a June 2018 VA Gulf War examination. The examiner found no pattern of illness that is unexplained, all diagnoses have clear and specific etiologies. There is no objective evidence of any chronic headache condition. In his subsequent June 2018 VA Headaches examination, the examiner found no objective evidence that a headache condition existed and thus no diagnosis was rendered. During his October 2021 Board hearing, the Veteran testified to experiencing headaches during service, including during his service in the Gulf, with continual symptoms to present day. Hearing Transcript, Page 11. He reported he has been given Motrin, Ibuprofen, Tylenol, and Aleve to relieve the symptoms. He testified his neurological issues could be causing his headaches. In addition, he stated "I've always had headaches, you know, for no reason." Hearing Transcript, Pages 10-11. During his June 2022 VA Headaches examination, a diagnosis of tension headaches was reported. Consistent with his Board hearing, the Veteran reported that he began to experience headaches in service, and elaborated his headaches began in 1991 and he experiences 1-2 headaches per month that last for several hours. During the corresponding June 2022 Gulf War examination, the examiner found no diagnosed illnesses for which no etiology was established. The examiner found no objective evidence of any chronic headache condition, as the Veteran denied headaches on his separation physical in October 1997. Pursuant to the May 2023 Board remand, addendum opinions were provided by a VA Neurologist in November 2023. Based on a review of the entire evidence of record, to include the lay statements of record (including the Veteran's hearing testimony), the TERA memorandum, and the Individual Exposure Summary Information (ILER), the Neurologist opined it was less likely than not that the Veteran's contended headaches had onset in or was otherwise related to service. The clinician noted consideration of the Veteran's testimony during his October 2021 hearing, to include that he has "always had headaches," and his headaches could be caused by his neurological issue. The Neurologist noted that the lay statements were reviewed and considered, and although this combat Veteran has reported his experiences and the clinician believes those experiences occurred, the Veteran is not qualified to make a medical diagnosis as the result of those experiences, as diagnoses of headache conditions are medical diagnoses. The Neurologist further opined that it is less likely than not that the Veteran's claimed headaches had their onset during service with continual symptoms since service or manifested to a compensable degree within one year of service. The clinician found that the evidence of record and the weight of the medical literature do not support the diagnosis of any chronic and disabling headache condition, either in-service or post-service. The examiner noted the Veteran has been seen on a handful of occasions for complaints of headaches; however, the Veteran's reported headaches represented acute and transitory symptoms that resolved without residuals and did not represent any separate and distinct chronic and disabling headache condition, as supported by the evidence of record and the weight of the medical literature. The clinician determined that the evidence does not support that while in-service or post-service the Veteran sought medical attention from any clinical treatment providers for any chronic and disabling headache conditions nor does the evidence support that while in-service or post-service the Veteran was evaluated for or objectively diagnosed with any chronic and disabling headache conditions by any clinical treatment providers. The examiner elaborated that the Veteran was seen on numerous occasions by his clinical treatment providers, to include his treating non-VA and VA neurologists, and none of them resulted in any complaints by the Veteran of, evaluated the Veteran for, diagnosed the Veteran with, or provided any clinical treatment for a chronic and disabling headache condition. Thus, the evidence does not support the Veteran's contention that his headaches had its onset during service with continual symptoms since service. The November 2023 Neurologist found there was no medical basis for the Veteran's indicated TERAs, including the total potential exposure through all applicable military deployments of the Veteran and the synergistic combined effect of all toxic exposure to cause his claimed headaches. As a rationale, the examiner explained no such direct and/or causal relationship existed, and that current medical literature did not support such a relationship between the development of the condition at issue and the TERAs. Therefore, the claimed condition was less likely than not caused by the indicated TERAs, after considering the total potential exposure through all applicable military deployments of the Veteran and the synergistic, combined effect of all TERAs of the Veteran. Regarding the Veteran's Southwest Asia service, the November 2023 Neurologist found there is no evidence for an undiagnosed illness, a diagnosable but medically unexplained chronic multi symptom illness of unknown etiology, or a diagnosable chronic multi symptom illness with partially explained etiology. In support, the Neurologist found there is no pathology or diagnosis found of any claimed condition, this does not imply that there is a condition that is undiagnosed, this is a statement that no condition exists to be diagnosed. The Veteran's claimed "headaches" are less likely than not related to a specific exposure event experienced by the Veteran during service in Southwest Asia. There is no current medical evidence supporting a causal relationship and/or direct relationship between the Veteran's claimed condition and his environmental exposure event. References were included to several medical articles on Gulf War Veterans' Illnesses and Airborne Hazards and Burn Pit Exposures. The November 2023 VA Neurologist opined that the Veteran's headache disability is less likely than not secondary to his restless leg syndrome. In support, the examiner noted that the weight of the medical literature does not support that restless leg syndrome causes or aggravates any chronic and disabling headache condition. Restless leg syndrome is a neurologic movement disorder condition that is due to altered function of various systems of the brain. The affected brain systems are not involved in the development of any chronic and disabling headache conditions, as supported by the evidence of record and the weight of medical literature. Likewise, the affected brain systems in restless leg syndrome do not aggravate any chronic and disabling headache condition, as supported by the evidence of record and the weight of the medical literature. References to a medical article on the clinical features and diagnosis of restless leg syndrome and periodic limb movement disorder in adults was included. Furthermore, the examiner opined his headache disability is less likely than not secondary to his neurological condition that has recently been diagnosed as hereditary spastic paraplegia (HSP). As the Veteran is not service connected for this disability, further discussion on this opinion will not be included. Analysis The Board has carefully reviewed the evidence of record and finds that the evidence persuasively weighs against the claim for service connection for headaches. The reasons follow. As to the first element of service connection, a current disability, the Veteran has a current diagnosis of tension headaches. See June 2022 VA examination. Thus, the element of a current disability is met, and the Veteran's headache disability is best characterized as tension headaches. As to the second element of service connection, an in-service incurrence, as discussed above, the Veteran's service treatment records (STRs) included two notations of headaches (March 1990 optometry examination during which the Veteran reported headaches with reading fine print and February 1990 STR he presented with complaints of stuffy nose, sinus pressure, and headaches for 1 day). Otherwise, the Veteran's STRs are devoid of complaints or treatment for headaches. For example, on examinations dated in June 1994, October 1997 (separation from active duty) and December 1997 (enlistment for Reserve service) each reflect clinical examination of the Veteran's neurologic system, as relevant to a headache disability, was normal. No chronic headache complaints were noted. Similarly, on his Report of Medical History in October 1992, June 1994, and October 1997, the Veteran self-reported "no" to frequent or severe headaches. Likewise, on his December 1997 Report of Medical History for enlistment into the Army Reserve, the Veteran self-reported his present health as "good" and responded "no" to frequent or severe headaches. Nonetheless, as he had reports of headaches in service, the second element of service connection is met. See 38 U.S.C. § 1154(a); Washington v. Nicholson, 19 Vet. App. 362, 368 (2005) (noting that a lay witness is competent to report to factual matters of which he or she has first-hand knowledge). As to the third element of service connection, a medical nexus, the Board finds that the evidence persuasively weighs against finding that the Veteran's tension headaches had their onset in service or are otherwise related to service, to include his environmental exposures and/or as secondary to service-connected disability. Initially, the Board acknowledges the negative evidence of record, including the June 2018 Gulf War/Headaches opinions and June 2022 Gulf War/Headaches opinions. However, as these opinions have previously been deemed to have limited probative value, they will not be discussed herein. In this case, there is no medical or other competent evidence of a nexus between the Veteran's headaches and service. The November 2023 Neurologist determined that the evidence of record does not support the diagnoses of any chronic and disabling headache condition, either in-service or post-service and provided sufficient rationale for such conclusion, finding that the Veteran has been seen on a handful of occasions for complaints of headaches; however, the Veteran's reported headaches represented acute and transitory symptoms that resolved without residuals and did not represent any separate and distinct chronic and disabling headache condition. The examiner elaborated that the Veteran was seen on numerous occasions by his clinical treatment providers, to include his treating non-VA and VA neurologists and did not result in complaints of any headache disability from the Veteran, nor diagnosis of a headache disorder from treatment providers. Thus, the evidence does not support the Veteran's contention that his headaches had its onset during service with continual symptoms since service. The Neurologist found the claimed condition was less likely than not caused or aggravated by service-connected restless leg syndrome and explained that the affected brain systems are not involved in the development of any chronic and disabling headache conditions, as supported by the evidence of record and the weight of medical literature. There is no contrary opinion of record. In relation to his TERA exposure, the Neurologist found the claimed condition was less likely than not caused by the indicated TERAs, after considering the total potential exposure through all applicable military deployments of the Veteran and the synergistic, combined effect of all TERAs of the Veteran. There is no contrary opinion of record. See 38 U.S.C. § 1168(b). Likewise, regarding the Veteran's Southwest Asia service, the November 2023 Neurologist found there is no evidence for an undiagnosed illness, a diagnosable but medically unexplained chronic multi symptom illness of unknown etiology, or a diagnosable chronic multi symptom illness with partially explained etiology. There is no contrary opinion of record. The Board affords the November 2023 neurologist opinions significant probative value as they were made by a medical professional with consideration of the Veteran's lay statements and specific facts in this case, and are supported by well-reasoned rationale. Factors for assessing the probative value of a medical opinion include the thoroughness and detail of the opinion. Prejean v. West, 13 Vet. App. 444, 448-9 (2000). A medical examination report must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 301 (2008). The Board finds no in-service chronic headache disorder. The in-service headaches noted in 1990 were neither chronic nor continuous, but ultimately resolved by the time of service discharge. In other words, the acute nature of the symptoms is evidenced by the Veteran's October 1997 separation examination during which he did not indicate headaches. Had the Veteran experienced continual headache symptoms during active service, it would have been reasonable for him to have reported it-this is supported by the VA examiner's findings noted above. In contrast, the Veteran repeatedly, and specifically denied any frequent or severe headaches during service, to include on his Report of Medical History in October 1992, June 1994, and October 1997, on which he self-reported "no" to frequent or severe headaches. Indeed, his October 1997 report of medical history for separation from active duty service documented the Veteran reported an allergy to Demerol and past history of a right hand disability. However, no mention of a headache disorder was noted. Moreover, as noted above, the November 2023 examiner found no evidence of a chronic headache condition. Thus, it is clear that a continuing permanent headache disorder was not present. Here, a gap of approximately 21 years exists in the Veteran's treatment records from the time of separation from service to when he reported for treatment for headaches. Although not dispositive, the passage of so many years between discharge from active duty and the initial demonstration of a diagnosis of a headache disability, approximately 21 years later, is a factor in weighing against a finding of service incurrence and continuity. Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000). The Board emphasizes that during his emergency room visit in 2018 that rendered a diagnosis of tension headaches, the Veteran reported onset of his headache two days prior. Statements made for the purpose of medical diagnosis or treatment are exceptionally credible because the declarant has a strong motive to tell the truth in order to receive proper medical care. See White v Illinois, 502 U.S. 346, 356 (1992). Thus, the Board finds no chronic headache disorder manifested in service or within one year thereafter. The Board accepts that the Veteran was competent to report symptoms of headaches. However, he is not competent to opine on the etiology of these conditions. The etiology of symptoms is a complex medical question beyond the knowledge of a layperson. Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). The Board finds that the question regarding the potential relationship between the Veteran's headaches and any instance or event of his service, to include his Persian Gulf War exposures, to be complex in nature. Woehlaert v. Nicholson, 21 Vet. App. 456 (2007). Specifically, even though the Veteran is competent to describe his current symptoms, the Board accords his statements regarding the etiology of his tension headaches little probative value because he is not competent to opine on such a complex medical question. Where the determinative issue is one of medical causation, only those with specialized medical knowledge, training, or experience are competent to provide evidence on the issue. See Jones v. Brown, 7 Vet. App. 134, 137 (1994). In the instant case, there is no suggestion that the Veteran has had any medical training. As such, the question of etiology in this case may not be competently addressed by lay evidence. Consequently, the Board gives more probative weight to the competent medical evidence discussed above. The Veteran's statements of continual symptoms following service are contradicted by post-service records. The Veteran had opportunities to identify pertinent headache symptoms during outpatient evaluations following service, when he reported other problems (including neurological concerns with the bilateral lower extremities), but did not do so. This suggests that the Veteran would have also sought care for chronic headaches, if such had existed, and is persuasive evidence that he was not then experiencing continuous headaches from the time of his discharge from service in 1997. In fact, a review of the available VA medical records do not show that the Veteran received any treatment for headaches through VA, nor was the condition listed as an active problem. He denied headaches in September 2017, March 2021, June 2023, and July 2023 VA treatment records. Contemporaneous statements, including those made to physicians for purposes of diagnosis and treatment, are generally entitled to greater probative value than history as reported by the Veteran. Curry v. Brown, 7 Vet. App. 59, 68 (1994); Rucker v. Brown, 10 Vet. App. 67, 73 (1997). In this case, the objective contemporaneous medical records stand in sharp contrast to the Veteran's lay reports surrounding continuity of his contended headache disorder and are more probative rather than his history reported years thereafter. Accordingly, the Board affords his lay assertions of continual symptoms following service low probative value. Further, the Veteran's asserted timeline of onset is inconsistent throughout the entirety of the appeal period. See Macarubbo v. Gober, 10 Vet. App. 388 (1997) (holding that the credibility of lay evidence can be affected and even impeached by inconsistent statements, internal inconsistency of statements, inconsistency with other evidence of record, facial implausibility, bad character, interest, bias, self-interest, malingering, desire for monetary gain, and witness demeanor). Essentially, at no time prior to filing his claim in 2018 did he report his headaches began in service, or he suffered from continual headache symptoms. Instead, the evidence reflects the opposite, that the Veteran denied headache symptoms, beginning on his separation examination. Then, when treated for headaches for the first time following service, he noted onset was 2 days prior. In contrast, during his June 2022 VA examination, he reported onset of headaches in 1991. Accordingly, the Board affords these lay assertions not credible and of low probative value. The Board has also considered whether presumptive service connection can be established where there is evidence of continuity of symptomology of a chronic condition since service. See 38 C.F.R. § 3.309. However, the evidence of record does not show a diagnosis of a chronic disability at any time, nor does the evidence show continuity of symptoms following service as detailed above. Therefore, consideration based on presumptive service connection for continuity of symptomatology is not warranted. 38 C.F.R. § 3.303. As the Veteran's tension headaches are a diagnosed condition, they cannot be considered an undiagnosed illness, but are eligible for consideration as a medically unexplained chronic multi-symptom illness. 38 C.F.R. § 3.317(a)(1)(ii), (a)(2)(ii). However, the November 2023 VA neurologist found the Veteran's headaches were not part of a medically unexplained chronic multi-symptom illness. There is no contrary opinion of record. Due to the inconsistencies noted above in the Veteran's lay statements regarding the origin and continuity of his headaches, the Board finds the lay statements lack credibility. Thus, in weighing the evidence, the Board finds the Veteran's service records, which are contemporaneous to his period of active service, and his post service medical records, which are contemporaneous to the post service period, are more probative than the argument that he experienced headaches during and since active duty service, made many years after service for compensation purposes. See Curry, 7 Vet at 68; Cartwright, 2 Vet. App. at 25-26. The Board's reliance on multiple factors, only one of which is an absence of complaints or treatment during the years after service, is consistent with the statutory and regulatory requirements to consider all evidence of record, as well as applicable precedential decisions. See Buchanan, 451 F.3d at 1336-37. Accordingly, the evidence is persuasively against the claim. As there is not an approximate balance of positive and negative evidence, the benefit-of-the-doubt doctrine is not applicable and service connection for headaches is not warranted. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Lynch, 21 F.4th at 781-82. H.M. WALKER Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Krista Johnson, 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.