Citation Nr: 21030578 Decision Date: 05/19/21 Archive Date: 05/19/21 DOCKET NO. 15-26 030 DATE: May 19, 2021 ORDER Entitlement to service connection for transient global amnesia, to include seizures, is denied. Entitlement to service connection for a visual disorder is denied. REMANDED Entitlement to service connection for sleep apnea is remanded. FINDINGS OF FACT 1. The Veteran has transient global amnesia, to include seizures, is not related to service. 2. A visual disorder is not related to service. CONCLUSIONS OF LAW 1. The criteria for entitlement to service connection for transient global amnesia, to include seizures, are not met. 38 U.S.C. §§ 1110, 5103, 5103A, 5107 (West 2014); 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.310 (2020). 2. The criteria for entitlement to service connection for a visual disorder are not met. 38 U.S.C. §§ 1110, 5103, 5103A, 5107 (West 2014); 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.310 (2020). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The appellant is a veteran (the Veteran) who had active duty service from June 1966 to November 1967. This appeal comes before the Board of Veterans' Appeals (Board) from an August 2019 Order of the United States Court of Appeals for Veterans' Claims (Veterans Court). The appeal originated from a January 2014 and June 2015 rating decisions of the Department of Veterans Affairs (VA) Regional Office (RO). In a November 2018 decision, the Board denied service connection for melanoma. The Board also granted reopening of service connection for an eye/vision disorder, and remanded the reopened claim. In addition, the Board remanded service connection claims for sleep apnea, amnesia, seizures, posttraumatic stress disorder (PTSD) and depression, tinnitus, diabetes mellitus, headaches, bilateral upper and lower extremity peripheral neuropathy, acid reflux, disorders of the thyroid and prostate, and TDIU. The Veteran appealed the November 2018 decision to the Veterans Court. In an August 2019 Order, pursuant to a Joint Motion for Remand, the Veterans Court vacated the Board's decision in part, and remanded the issue of service connection for melanoma to the Board for additional development consistent with the Joint Motion. In February 2020, on remand from the Board, the agency of original jurisdiction granted service connection for PTSD and tinnitus, and granted TDIU, effective November 9, 2012. In a July 2020 decision, the Board granted service connection for GERD and headaches, and denied service connection for melanoma, diabetes mellitus, a prostate disorder, and peripheral neuropathy of the bilateral upper and lower extremities. The Board also remanded service connection for a thyroid disorder, sleep apnea, a vision disorder, and transient global amnesia, to include seizures. In a February 2021 decision the agency of original jurisdiction granted service connection for a thyroid disorder and implemented the grant of service connection for headaches and GERD. In March 2021, VA corrected several of the effective dates assigned based on Clear and Unmistakable Error (CUE). The matters remaining before the Board upon return from the July 2020 remand are service connection for sleep apnea, a vision disorder, and transient global amnesia, to include seizures. SERVICE CONNECTIONLAW AND REGULATIONS VA law provides that, for disability resulting from personal injury suffered or disease contracted in line of duty, or for aggravation of a preexisting injury suffered or disease contracted in line of duty, in the active military, naval, or air service, during a period of war, or other than a period of war, the United States will pay to any veteran thus disabled and who was discharged or released under conditions other than dishonorable from the period of service in which said injury or disease was incurred, or preexisting injury or disease was aggravated, compensation, except if the disability is a result of the veteran's own willful misconduct or abuse of alcohol or drugs. 38 U.S.C. §§ 1110, 1131 (West 2014). Entitlement to service connection on a direct basis requires (1) evidence of current nonservice-connected disability; (2) evidence of in-service incurrence or aggravation of disease or injury; and (3) evidence of a nexus between the in-service disease or injury and the current nonservice-connected disability. 38 C.F.R. § 3.303(a); Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004); Saunders v. Wilkie, 886 F.3d 1356 (2018). Service connection on a secondary basis requires (1) evidence of a current nonservice-connected disability; (2) evidence of a service-connected disability; and (3) evidence establishing that the service-connected disability caused or aggravated the current nonservice-connected disability. 38 C.F.R. § 3.310. VA has established a presumption of exposure to herbicide agents applicable to veterans who served in the Republic of Vietnam during the Vietnam War, and a presumption of service connection applicable to veterans who are either presumed to have been exposed to herbicide agents, or who are shown to have been actually exposed to herbicide agents during service. A veteran who, during active military, naval, or air service, served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, shall be presumed to have been exposed during such service to an herbicide agent, unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service. The last date on which such a veteran shall be presumed to have been exposed to an herbicide agent shall be the last date on which he or she served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975. 38 C.F.R. § 3.307(a)(6)(iii). A disease covered by 38 U.S.C. § 1116 becoming manifest as specified in that section in a veteran who, during active military, naval, or air service, served offshore of the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, shall be considered to have been incurred in or aggravated by such service, notwithstanding that there is no record of evidence of such disease during the period of such service. 38 U.S.C. § 1116(a). A veteran who, during active military, naval, or air service, served offshore of the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, shall be presumed to have been exposed during such service to an herbicide agent unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service. 38 U.S.C. § 1116(b); 38 U.S.C. § 1116A (those who served in the 12-nautical-mile territorial sea of the "Republic of Vietnam" are entitled to the presumption of herbicide exposure). If a veteran was exposed to an herbicide agent during active military, naval, or air service, the following diseases shall be service-connected if the requirements of § 3.307(a)(6) are met even though there is no record of such disease during service, provided further that the rebuttable presumption provisions of § 3.307(d) are also satisfied. AL amyloidosis, chloracne or other acneform disease consistent with chloracne, type 2 diabetes (also known as Type II diabetes mellitus or adult-onset diabetes), Hodgkin's disease, ischemic heart disease (including, but not limited to, acute, subacute, and old myocardial infarction; atherosclerotic cardiovascular disease including coronary artery disease (including coronary spasm) and coronary bypass surgery; and stable, unstable and Prinzmetal's angina), all chronic B-cell leukemias (including, but not limited to, hairy-cell leukemia and chronic lymphocytic leukemia), multiple myeloma, non-Hodgkin's lymphoma, Parkinson's disease, early-onset peripheral neuropathy, porphyria cutanea tarda, prostate cancer, respiratory cancers, and soft-tissue sarcoma. 38 C.F.R. § 3.309(e). Generally, lay evidence is competent with regard to identification of a disease with unique and readily identifiable features which are capable of lay observation. See Barr v. Shinseki, 21 Vet. App. 303, 311 (2007). A lay person may speak to etiology in some limited circumstances in which nexus is obvious merely through observation, such as sustaining a fall leading to a broken leg. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009); Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir 2007). Lay persons may also provide competent evidence regarding a contemporaneous medical diagnosis or a description of symptoms in service which supports a later diagnosis by a medical professional. However, a lay person is not competent to provide evidence as to more complex medical questions, i.e., those which are not capable of lay observation. Lay statements are not competent evidence regarding diagnosis or etiology in such cases. See Woehlaert v. Nicholson, 21 Vet. App. 456, 462 (2007) (concerning rheumatic fever); Jandreau, at 1377, n. 4 ('sometimes the layperson will be competent to identify the condition where the condition is simple, for example a broken leg, and sometimes not, for example, a form of cancer'); 38 C.F.R. § 3.159(a)(2). After the evidence has been assembled, it is the Board's responsibility to evaluate the entire record. 38 U.S.C. § 7104(a). When there is an approximate balance of evidence regarding the merits of an issue material to the determination of the matter, the benefit of the doubt in resolving each such issue shall be given to the claimant. 38 U.S.C. § 5107; 38 C.F.R. §§ 3.102, 4.3. A VA claimant need only demonstrate that there is an approximate balance of positive and negative evidence in order to prevail. Gilbert v. Derwinski, 1 Vet. App. 49, 53 (1990). To deny a claim on its merits, the preponderance of the evidence must be against the claim. Alemany v. Brown, 9 Vet. App. 518, 519 (1996), Gilbert at 54. Entitlement to service connection for transient global amnesia, to include seizures. Entitlement to service connection for a visual disorder. Service treatment records reveal no complaint of, treatment for, or diagnosis of transient global amnesia, seizures, or a visual disorder. The agency of original jurisdiction requested the Veteran's service treatment records from the National Personnel Records Center, but the record is apparently incomplete. Notably, there is no service separation examination of record. In these circumstances, when pertinent service records are unavailable through no fault of the Veteran, VA's duties to assist, to provide reasons and bases for its findings and conclusions, and to carefully consider the benefit-of-the-doubt rule are heightened. Milostan v. Brown, 4 Vet. App. 250, 252 (1993) (citing Moore v. Derwinski, 1 Vet. App. 401, 406 (1991) and O'Hare v. Derwinski, 1 Vet. App. 365, 367 (1991)). The Veteran was separated from active duty service on November 3, 1967. He filed a claim seeking service connection for concussion/head injury and an eye disorder the following month. That claim was denied in February 1968 these claims appear to be related to his assertion that he incurred an eye injury due to contact with lead paint in March 1967. A post-service December 1967 VA examination report reflects that the Veteran's conjunctivae were slightly red, but he had no double vision and no blurred vision. On examination of the Veteran's eyes, conjunctivae were slightly red, but sclera were white; the pupils were round, regular, equal, and reactive; funduscopic examination disclosed no hemorrhages, exudates, or papilledema. There was no evidence of cranial trauma. On examination, cranial nerves were intact. The Veteran noted only a single episode of slight dizziness which went away in just a few seconds. "This was in the past" (Record 12/11/1967). In a statement received in March 1968, the Veteran's father reported he had lead based paint splashed in his eyes (Record 03/28/1968). A December 11, 1987, private Clinical Note reveals complaint of gaps in memory (amnesia) (Record 12/10/2013 at 2). A March 1988 Bay Pacific Health Plan referral/consultation form reflects that the Veteran had "tunnel vision", along with other complaints and was to be seen to rule out multiple sclerosis (Record 04/27/2016). An August 29, 2002, Private Clinical Note reveals a questioned finding of transglobal amnesia or seizure (Record 01/14/2014 at 19). A December 19, 2002, Private Clinical Note gives a history of seizure disorder characterized as transglobal amnesia. The Veteran was on Tegretol (Record 01/14/2014 at 21). A December 28, 2006, Private Clinical Note reveals the Veteran's denial of blurred vision (Record 01/14/2014 at 26). A March 23, 2010, Private Clinical Note reveals normal examination of the eyes (Record 01/14/2014 at 72). A VA Form 21-4138 (Statement in Support of Claim) received in August 2011 notes the Veteran's contention that he was exposed to Agent Orange in Puerto Rico (Record 08/11/2011). A VA Form 21-526 (Veteran's Application for Compensation and/or Pension) received in August 2012 notes the Veteran's contention that he was in charge of landscaping on Puerto Rico while his duty assignment was being worked out. He was told that herbicides used in Vietnam were being sprayed to kill vegetation in the area (Record 08/17/2020). A letter from the Veteran's wife received in August 2012 reveals that, in the 1980s, he started to vision problems where he had a difficult time with side vision (Record 08/17/2012). In a statement received in August 2012, the Veteran reported that seizures and vision problems were due to exposure to herbicide agents (Record 08/17/2012). In a statement from the Veteran's child received in August 2012, it was reported: For as far back as I can remember, My Father, [...] has had several debilitating conditions which have affected his and our families quality of life. My father has suffered from lapses of memory since I was a toddler. During my childhood, my father would become disoriented, no longer responding to basic commands or instructions, and wander off for hours and in some cases days at a time. After my father regained consciousness, he would remember nothing of the previous hours. It was as though his body was functioning without him. In smaller incidences, I would notice lack of focus or trouble following direction aid instruction. There would also be times where his speech would become labored. He would have trouble recalling words or putting sentences together[...]My father also has loss of his peripheral vision which affects driving and walking. He has to be very careful to turn his head when crossing the street or driving to- make sure he has a clear view of oncoming traffic (Record 08/17/2012). In a statement received in November 2012, the Veteran reported that vision problems started soon after he returned home from the Navy. He started to lose his peripheral vision. He also reported that he was told by a doctor that he was suffering from seizures in 1986 (Record 11/09/2012). A January 9, 2013, Private Clinical Note reveals no visual disturbances, but a notation of early macular degeneration (Record 01/14/2014 at 7-10). A September 2, 2014, VA Mental Health Note reveals the Veteran's report of chronic health problems including a seizure disorder (Record 11/05/2019 at 274). A December 5, 2014, VA Mental Health Note reveals the Veteran's report of a history positive for seizures. The Veteran reported hitting the back of his head in a motor vehicle accident at age 16. He was reportedly hospitalized and had some loss of consciousness/coma for 2 days. According to the Veteran, "they called it transg[l]obal amnesia"; he reported seizures associated with some loss of memory/awareness during these episodes. He reported that it is currently reportedly under control with medication (Record 11/05/2019 at 260). A February 2021 VA examination of the eyes includes diagnoses of intraocular lens, bilaterally, and macular drusen, bilaterally. The Veteran reported that he sprayed lead paint into his eyes while he was in service. After that, he felt his vision was not clear. His visual fields were very limited according to visual field testing. The results of his very restricted visual fields should be a safety concern as he states he still drives a car. Driving limitations should be brought up to his PCP and eye care provider (Record 02/09/2021). The examiner opined that the condition claimed was less likely than (less than 50 percent probability) related to service. The rationale was that the service treatment records do not show cataracts and macular Drusen while in service, and these conditions are not attributable to PTSD. Limited peripheral vision was also not noted in his service treatment records. In 2012, the Veteran stated his problems with peripheral vision began after leaving service. Test results showing peripheral vision loss were not found during review of records. Regarding aggravation, the examiner opined that the eye conditions were not aggravated by the service-connected PTSD. The rationale was that these were more likely age-related and less likely than not aggravated beyond their natural progression by PTSD (Record 02/09/2021). A February 2021 VA examination reveals a diagnosis of transglobal amnesia with temporal lobe seizures. The date of diagnosis is 2014. The Veteran reported that "In 1983/84, a neurologist in San Francisco had diagnosed me with transient global amnesia seizures. According to my wife and daughter, there were a few incidents where I wandered and lost track of time for hours. Per my wife, roughly for about 5 hours. The doctor diagnosed me, and my driver's license was suspended. I was taking Tegretol, and in 2002, it started affecting my liver, and my doctor took me off it and switched me to topiramate. I had seen other neurologists, but they just continued my medication (topiramate). I have been told that I had epilepsy and seizure episodes, but I don't remember any events." He continued, "I have not had another episode since the 80s." There was no impact of the condition on the Veteran's ability to work (Record 02/09/2021). The examiner opined that the claimed condition was less likely than not (less than 50 percent probability) proximately due to or the result of, or aggravated by, the Veteran's service connected PTSD. The examiner reasoned that the exact cause of transient global amnesia is unknown, and the cause of temporal lobe seizures remains unknown. Temporal lobe epilepsy (seizures) and PTSD have been rarely reported to co-occur. The examiner noted that PTSD neither causes nor has it aggravated his condition (Record 02/09/2021). After a review of all of the evidence, the Board finds that the criteria for entitlement to service connection for a visual disorder and/or transient global amnesia are not met. The Board initially finds that its remand instructions were substantially complied with. The agency of original jurisdiction attempted to obtain outstanding records identified by the Veteran and requested the Veteran to submit any records in his possession. See Stegall v. West, 11 Vet. App. 268 (1998); D'Aries v. Peake, 22 Vet. App. 97, 105 (2008); Dyment v. West, 13 Vet. App. 141, 146-47 (1999) (holding that there was no Stegall violation when the examiner made the ultimate determination required by the Board's remand). There is a current disability regarding the claimed transient global amnesia, confirmed by the February 2021 VA examination. There is also a confirmed current disability of cataracts and macular drusen, with confirmed symptomatology of narrowed visual fields. Regarding an eye injury or disease in service, the Veteran has been inconsistent in his assertions. He has alternatively related an eye disorder directly to service, from splashing paint into his eyes, but has also asserted his eye conditions were due to exposure to herbicide agents in Puerto Rico. The Veteran relates transient global amnesia to exposure to herbicide agents or as secondary to PTSD. While the Veteran has asserted sustaining an eye injury in service, he has maintained that his claimed visual disorder began after service. In November 2012, he asserted that his vision problems began soon after he returned home from the Navy. He maintained that he was first told he had seizures in 1986 (Record 11/09/2012). Thus, the incomplete service treatment records and absence of a service separation examination are not necessarily problematic, as the Veteran does not contend that he complained of, or was treated for, associated symptoms in service. Post-service onset of visual disorders and amnesia/seizures is supported by the pertinently normal examination in December 1967. While there is no service separation examination of record, the December 1967 examination provides probative evidence that there was no visual disorder present shortly after service separation. Indeed, the first record of treatment for eye complaints did not appear until March 1988, more than 20 years after service separation. That complaint was for tunnel vision. Neither of the currently diagnosed disorders were noted. The December 1967 examination also provides probative evidence that there was no transient global amnesia or seizures present at that time. Regarding exposure to herbicide agents, there are two basic presumptions applicable to herbicide agents: (1) the presumption of exposure to herbicide agents, and (2) the presumption of service connection for certain diseases which VA has designated as associated with exposure to herbicide agents. The presumption of exposure to herbicide agents does not apply to veterans who served in Puerto Rico. The Veteran has not asserted that he was present in any areas to which VA's legal presumption of exposure applies. Accordingly, his exposure must be demonstrated by the facts of the case. The agency of original jurisdiction attempted to verify any exposure to herbicide agents during the Veteran's service; however, this produced negative results (Record 09/07/2021). The response from the service department reveals that Agent Orange, tactical herbicides, and other types of herbicides, were not documented as being used tested disposed of or stored on Naval Air Station Roosevelt Roads during the period January 1 to December 31, 1966. Other available historical information confirms Agent Orange use in certain locations on Puerto Rico in the past; however, the information does not document Agent Orange usage or spraying at the Veteran's location during the period of his service (Record 11/19/2012). A VA Memo discusses the attempts to verify the allegations and concludes that there is insufficient information to perform further research (Record 12/26/2012). The Veteran's exposure to Agent Orange/tactical herbicides could not be documented. The Board also notes that the Veteran does not have any of the diseases that are shown or acknowledged to be associated with herbicide agents. He has been diagnosed with cataracts, macular drusen, and transient global amnesia/seizures. These are not herbicide-presumptive diseases listed under 38 C.F.R. § 3.309(e). Therefore, the presumption of service-connected for the diseases specified under that section does not apply. As neither of the presumptions regarding herbicide agents applies in this case, the decision thus turns to consideration of direct service connection. See Combee v. Brown, 34 F.3d 1039, 1043 (Fed. Cir. 1994). The Veteran's assertion regarding actual exposure to Agent Orange is not based on first-hand knowledge, but is based on information he claims he was told by another individual. While the Veteran is competent to state that he was present in areas where chemicals were applied, or that he participated in the application of chemicals, he is not competent to identify the contents of those chemicals. His statement that he was told they were using the same herbicides used on Vietnam is also not competent evidence, as the Veteran has not described the qualifications of the individual from whom this information was obtained. The fact that a fellow servicemember told him that Agent Orange, or similar herbicide was being applied does not render such information competent evidence. As such, based on the Veteran's statements and description of his alleged exposure, the Board finds that there is not competent evidence of actual exposure to herbicide agents as defined under 38 C.F.R. § 3.307(a)(6)(i), in this case. To the extent the Veteran's is basing his claim on exposure to commercial herbicides, there is no medical opinion of record that purports to relate any of his claimed disorders to such exposure, or to any injury or disease incurred in service. The medical opinion evidence finds that the current eye/visual disorders are not related to service, but are age-related eye disorders. Regarding the claimed transient global amnesia and seizures, there is no medical opinion that purports to relate such disorder to service. The only opinion evidence is against secondary service connection or aggravation due to PTSD. The Board has considered whether additional medical opinions are necessary, but finds that they are not. There is no medical opinion addressing direct service connection for transient global amnesia; however, there is no injury or disease in service that may reasonably be related to transient global amnesia. As discussed above, the Veteran was not exposed to herbicide agents, and there is no evidentiary basis to interpret exposure to commercial herbicides as an injury. While the Veteran is reported to have ingested a half-pint of isopropyl alcohol in November 1966, he was seen in the ER and reported feeling lightheaded and dizzy. With the exception of slurred speech and unsteady gait, physical examination was within normal limits, and he was asymptomatic the following day. The diagnosis was intoxication (Record 07/18/2012 at 45). There is no indication or assertion that this incident "may be associated" with the current transient global amnesia or eye disorder. McLendon v. Nicholson, 20 Vet. App. 79 (2006). There is no opinion addressing secondary service connection for an eye disorder; however, there is no evidentiary basis to conclude that a service-connected disability "may be associated" with incurrence or aggravation of eye/visual disorders. The Federal Circuit has addressed the appropriate standard to be applied in determining whether an examination is warranted. In Waters v. Shinseki, 601 F.3d 1274 (Fed. Cir. 2010) and Colantonio v. Shinseki, 606 F.3d 1378 (Fed. Cir. 2010), the Federal Circuit held that medically competent evidence is not required to indicate that a current disability may be associated with service. On the other hand, a conclusory generalized lay statement suggesting a nexus between a current disability and service would not suffice, as this would, contrary to the intent of Congress, result in medical examinations being "routinely and virtually automatically" provided to all veterans claiming service connection. Waters, 601 F.3d at 1278-1279. Here, as noted, the Veteran has made no assertion regarding secondary service connection for an eye disorder or an association between transient global amnesia and alcohol consumption. Accordingly, there is not even a conclusory generalized lay statement suggesting such a nexus. The Board has considered the Veteran's lay statements regarding etiology. While the Veteran is competent to describe getting paint in his eye, he is not competent to relate any current disability of the eyes to this incident, in particular, as it would appear to have been of temporally remote onset. Thus, while there is competent evidence that the Veteran splashed paint in his eyes during service, the evidence does not substantiate a concurrent eye/visual disorder. Relating current cataracts and post-surgical changes, macular drusen, and/or transient global amnesia to temporally remote events in service, or to a service-connected disability, is not the equivalent of relating a broken bone to a concurrent injury to the same body part (Jandreau, at 1377). These issues are medically complex, as they require knowledge of the potential causes and contributory factors for development of such disorders. These matters are outside the competence of a layperson. Such an opinion is not capable of lay observation. Accordingly, the Veteran's lay statements are unpersuasive as to an etiologic relationship between the claimed eye disorders and/or transient global amnesia, and service or service-connected disability. See King v. Shinseki, 700 F.3d 1339, 1345 (Fed. Cir. 2012). In sum, the Board finds that the claimed eye/visual disorder and transient global amnesia are not related to service, and are not related by causation or aggravation to any service-connected disability. In light of these findings of fact, the Board concludes that service connection for the claimed disorders is not warranted. In reaching this conclusion, the Board has considered the applicability of the benefit-of-the-doubt doctrine. However, as the preponderance of the evidence is against each claim, that doctrine is not applicable. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert, 1 Vet. App. at 53-56. REASONS FOR REMAND Entitlement to service connection for sleep apnea. In the July 2020 remand, the Board noted in its discussion of the evidence that a May 2017 sleep study was inconclusive as to a diagnosis of sleep apnea. The Board stated: "A sleep study is needed to determine whether the Veteran has true sleep apnea or other sleep related symptoms that could be compensated as part of his PTSD rating" (Record 04/27/2021). However, in the actual remand instructions, the Board instructed only that a VA examination be conducted and that a secondary service connection nexus opinion be obtained. No sleep study was ordered. As the Board explicitly reasoned that a sleep study was "needed," the Board finds that the absence of such a study, or any attempt to obtain such a study, renders the record incomplete. Accordingly, the Board finds that further development on this issue is necessary. The matters are REMANDED for the following action: 1. Schedule a sleep study to determine whether the Veteran has sleep apnea or other identified sleep disorder other than the currently service-connected chronic sleep impairment associated with his mental disability. The standard regarding a diagnosis of sleep apnea or other sleep disorder is at least 50 percent likelihood. If the sleep study results in a diagnosis of a sleep disorder, to include sleep apnea, obtain a medical opinion as to whether such disorder is at least as likely as not (likelihood at least 50 percent) related to the Veteran's service; or related by causation or aggravation to a service-connected disability. Note: The term "at least as likely as not" does not mean merely within the realm of medical possibility, but that the medical evidence for and against a conclusion is so evenly divided that it is as medically sound to find in favor of causation or worsening as it is to find against causation or worsening. All opinions are to be accompanied by a rationale consistent with the evidence of record. A discussion of the pertinent evidence, relevant medical treatises, and generally accepted medical principles is requested. If the examiner cannot provide an opinion without resorting to speculation, he or she shall provide complete explanations stating why this is so. In so doing, the examiner shall explain whether any inability to provide a more definitive opinion is the result of a need for additional information, or that he or she has exhausted the limits of current medical knowledge in providing an answer to that particular question. Adjudicate the remanded claim. If the benefit sought on appeal is not granted, the Veteran and his representative should be provided a supplemental statement of the case and an appropriate time period for response. The case should then be returned to the Board for further consideration, if otherwise in order. JONATHAN B. KRAMER Veterans Law Judge Board of Veterans' Appeals Attorney for the Board L. Cramp 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.