Citation Nr: 20060993 Decision Date: 09/16/20 Archive Date: 09/16/20 DOCKET NO. 14-00 389 DATE: September 16, 2020 ORDER Entitlement to service connection for a lumbar spine disability is denied. FINDINGS OF FACT 1. The Veteran has spina bifida which is a congenital defect that is not shown to have been subject to a superimposed disease or injury in service. 2. The Veteran’s low back disability, other than spina bifida, was not shown in service, was not diagnosed within one year of service discharge, and is not otherwise etiologically related to his service. CONCLUSION OF LAW The criteria for service connection for a lumbar spine disability have not been met. 38 U.S.C. §§ 1110, 1111 (2012); 38 C.F.R. §§ 3.303, 3.306 (2019). REASONS AND BASES FOR FINDINGS AND CONCLUSION The Veteran served on active duty from December 1965 to October 1967. This matter comes before the Board of Veterans’ Appeals (Board) on appeal from a December 2012 rating decision of a Department of Veterans Affairs (VA) Regional Office (RO). The Veteran presented testimony before a Decision Review Officer (DRO) in February 2014. A transcript of the proceeding is associated with the claims file. This matter was previously before the Board in November 2015, when it was reopened and remanded for additional development. A December 2017 Board decision denied service connection for a lumbar spine condition, claimed as spina bifida. Importantly, an April 2019 Memorandum Decision from the United States Court of Appeals for Veterans Claims (Court) set aside the Board’s December 2017 decision and remanded the issue for appropriate action. In October 2019, the Board remanded this issue for additional development. As a threshold issue, the Board observes that it also remanded several other claims in its November 2015 order. However, as also highlighted in the December 2017 decision, these matters are not currently ripe for adjudication before the Board and will not be further addressed, as a Board videoconference hearing pertaining to these matters was requested in an October 2016 VA Form 9. See 38 C.F.R. §§ 3.103 (c), 20.904. The Veteran was also recently sent a May 2019 VA letter to clarify his request. To date, no determinative response has been received. Consistent with the approach in December 2017, and in order to avoid undue delay, the Board will proceed with this specific claim for service connection for a lumbar spine disability pursuit to the April 2019 Memorandum Decision. Thus, the only issue that is currently before the Board is entitlement to service connection for a lumbar spine disability. Service Connection Laws and Regulations Service connection will be granted if the evidence demonstrates that a current disability resulted from an injury or disease incurred in or aggravated by active military service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). To establish a right to compensation for a present disability, a Veteran must show: “(1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service.” Davidson v. Shinseki, 581 F.3d 1313, 1315-16 (Fed. Cir. 2009); Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Certain diseases, to include arthritis, may be presumed to have been incurred in service when manifest to a compensable degree within one year of discharge from active duty. 38 U.S.C. § 1112 (2012); 38 C.F.R. §§ 3.307, 3.309 (2019). Under 38 C.F.R. § 3.303(b), an alternative method of establishing the second and third Shedden for certain chronic disabilities such as arthritis is through a demonstration of continuity of symptomatology. In relevant part, 38 U.S.C. § 1154(a) requires that the VA give “due consideration” to “all pertinent medical and lay evidence” in evaluating a claim to disability or death benefits. Lay evidence can be competent and sufficient to establish a diagnosis of a condition when (1) a layperson is competent to identify the medical condition, (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional.” Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed.Cir.2007). In fact, competent medical evidence is not necessarily required when the determinative issue involves either medical etiology or a medical diagnosis. Id. at 1376-77; see also Buchanan v. Nicholson, 451 F.3d 1331, 1337 (Fed. Cir. 2006); Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). Once evidence is determined to be competent, the Board must determine whether such evidence is also credible. See Layno, supra (distinguishing between competency (“a legal concept determining whether testimony may be heard and considered”) and credibility (“a factual determination going to the probative value of the evidence to be made after the evidence has been admitted”). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the VA shall give the benefit of the doubt to the claimant. 38 U.S.C. § 5107(b). Congenital or developmental defects, personality disorders, mental deficiency, and other such “defects,” are not compensable diseases or injuries within the meaning of veterans’ benefits law, and therefore service connection for them is generally precluded by regulation. 38 C.F.R. §§ 3.303 (c), 4.9. VA General Counsel has held, however, that service connection may be granted for diseases (but not defects) of congenital, developmental or familial origin if the evidence as a whole shows that the manifestations of the disease in service constituted “aggravation” of the disease within the meaning of applicable VA regulations. VAOPGCPREC 82-90; 56 Fed. Reg. 45711 (1990). The provisions of 38 U.S.C. § 1111 provide that every veteran shall be taken to have been in sound condition when examined, accepted, and enrolled for service, except as to defects, infirmities, or disorders noted at the time of examination, acceptance, and enrollment, or where clear and unmistakable evidence demonstrates that the injury or disease existed before acceptance and enrollment and was not aggravated by such service. This presumption attaches only where there has been an induction examination in which the later complained-of disability was not detected. Bagby v. Derwinski, 1 Vet. App. 225, 227 (1991). A pre-existing injury or disease noted at entry will be considered to have been aggravated by active service where there is an increase in disability during such service, unless clear and unmistakable evidence shows that the increase in disability is due to the natural progress of the disease. 38 U.S.C. § 1153; 38 C.F.R. § 3.306. The provisions of 38 C.F.R. § 3.306(b) provide that aggravation may not be conceded unless the pre-existing condition increased in severity during service. An important distinction between section 1111’s aggravation prong of the presumption of soundness and section 1153 presumption of aggravation is the burden of proof. Under section 1111, the burden is on the Government to show by clear and unmistakable evidence that there was no increase in disability in service or, that any increase was due to the natural progress of the disease. Wagner v. Principi, 370 F.3d 1089, 1096 (Fed. Cir. 2004). Under section 1153, however, the Appellant bears the burden of showing that his preexisting condition worsened in service. Once the veteran establishes worsening, the burden shifts to the Secretary to show by clear and unmistakable evidence that the worsening of the condition was due to the natural progress of the disease. Horn v. Shinseki, 25 Vet. App. 231, 235 (2014). A pre-existing injury or disease will be considered to have been aggravated by active military, naval or air service, where there is an increase in disability during such service, unless there is a specific finding that the increase in disability is due to the natural progress of the disease. 38 U.S.C. § 1153; 38 C.F.R. § 3.306(a). Where a veteran asserts service connection for injuries or disease incurred or aggravated in combat, 38 U.S.C. § 1154 (b) and its implementing regulation, 38 C.F.R. § 3.304 (d), are applicable. These provisions ease the evidentiary burden of a combat veteran by permitting the use, under certain circumstances, of lay evidence. If the veteran was engaged in combat with the enemy, VA shall accept as sufficient proof of service connection satisfactory lay or other evidence of service incurrence or aggravation, if the evidence is consistent with the circumstances, conditions, or hardships of such service. 38 U.S.C. § 1154 (b); 38 C.F.R. § 3.304 (d); see also Caluza v. Brown, 7 Vet. App. 498, 507 (1995); Collette v. Brown, 82 F.3d 389, 393 (Fed. Cir. 1996) (providing that “satisfactory evidence” means “credible evidence”). Factual Background and Analysis The Veteran contends that he is entitled to service connection for a lumbar spine condition, claimed as spina bifida. The Veteran essentially maintains that his congenital spina bifida was aggravated by physical strain during military service from marching, exercising, carrying heavy materials, such as a radio, ammunition, and sandbags, or by reported in-service injuries, to include jumping off the back of a truck and/or falling several feet from an elevated bunker. The Board notes that in a June 2013 notice of disagreement and a December 2016 VA Form 9, the Veteran’s attorney asserted that the Veteran’s lumbar spine condition was aggravated during combat and that, as a result, 38 U.S.C. § 1154 (b) applies. In a September 1965 pre-induction report of medical history, the Veteran denied a history of back-related symptoms. A corresponding report of medical examination provides that with respect to the Veteran’s back, there was an excision of a cyst on the low back at infancy, “meningocele?,” and an X-ray that showed spina bifida. The summary of defects and diagnoses appears to note “failure fusion dorsal arch sacrum.” A September 1965 X-ray report of the Veteran’s lumbar spine notes failure of fusion of dorsal arch of sacrum consistent with history of meningocele. The Veteran was treated for a “nervous stomach” in January 1966, and the impression was “negative.” The Veteran also complained of abdominal pain in February 1966. It was noted that the Veteran had experienced this several times before. There was some nausea, but the Veteran denied vomiting or diarrhea. In an August 1966 periodic report of medical examination, the Veteran was clinically evaluated as normal except for a scar on his lumbar spine. In January 1967, the Veteran was treated for urethritis, unspecified. A prostatic smear and the Veteran’s urine were within normal limits. In an October 1967 report of medical history on separation from service, which is signed by the Veteran, he denied any history of musculoskeletal symptoms. In a corresponding report of medical examination, he was clinically evaluated as normal except for a rash on his penis. There were no noted defects or diagnoses. In this regard, the Board notes that in a July 2013 notice of disagreement, the Veteran’s attorney asserted that the Veteran was never given a discharge physical. In support of this contention, the Veteran’s attorney wrote that the Veteran only recalled receiving his pay and a new uniform on his last day. He also noted that the physical profile contained in the Veteran’s October 1967 separation examination report was “111111A,” and that his physical profile in a DA Form 1811 that was completed on the same date was “211111B,” which was the same as the physical profile noted on the Veteran’s September 1965 pre-induction report of medical examination. Following service, treatment records dated between 1978 and 2002 show treatment primarily for urinary symptoms and do not reflect treatment or complaints related to the Veteran’s low back. A September 1988 urological consultation noted that the Veteran had a history of urinary and bowel problems that were “absolutely consistent” with a meningomyelocele and spina bifida. A November 2003 letter from neurologist Dr. A. to Dr. J. indicates that the Veteran reported low back pain, in addition to bowel and bladder symptoms. The impressions included low back pain. According to a December 2003 letter from Dr. A., the Veteran continued to complain of low back pain, and while a December 2003 MRI showed no evidence of trauma, it did show lower spinal dysraphism with tethered spinal cord, distention of the distal spinal canal, and spina bifida. Letters from Dr. A. dated in August 2004 contain no notations regarding low back symptoms. A problem list from a VA primary care initial evaluation note from November 2004 includes spina bifida, history of low back pain, and VA primary care problem lists since that time continue to note spina bifida. In April 2006, the Veteran gave testimony at a DRO hearing. The Veteran testified that he was not aware of any serious back problems before his military service. The Veteran maintained that although he was told he had spina bifida, he was asymptomatic prior to service. He testified that he began to have back-related problems shortly before and during his tour in Vietnam. Specifically, he began to get headaches, have bowel and bladder problems, “extreme” lower back pain, and “sciatica” in his left leg. When asked whether there was anything he did during service that he felt would have aggravated his spina bifida, the Veteran replied that there was “spinal compression” from basic training, marches, and exercises. He also maintained that carrying and/or setting up a twenty-five pound PRC-25 radio, sandbags, and ammunition contributed to increased spina bifida symptoms. The Veteran did not raise any specific injuries that occurred during service. In a May 2006 letter from C.N.B.S., it was noted that the Veteran described a longstanding history of lumbar spina bifida with meningomyelocele that required open repair at the time of birth and that the Veteran’s congenital findings have left him with neurogenic bladder and constipation, and that following his service in Vietnam, the Veteran has had chronic low back pain and recurrent bladder infections. The Veteran eventually developed subsequent transient lower extremity numbness and paresthesia. The treating provider gave a diagnosis of spina bifida with myelodysplasia and wrote that based on the Veteran’s history, it was clear that the symptoms of neurogenic bladder, bowel dysfunction, and low back pain were aggravated during military service in Vietnam. Additionally, based on the Veteran’s history, there was a clear progression of medical involvement to manage back pain subsequent to military service. The treating provider agreed with the Veteran that in all medical probability, the rigors of military service did indeed aggravate the underlying condition of spina bifida with meningomyelocele beyond its natural progression. In June 2006, the Veteran wrote a statement regarding his service in Vietnam. The Veteran wrote about hauling sandbags and that it was around this time that he started getting treated for chronic cystitis, bowel issues, and low back problems. The Veteran noted experiencing neck pain and headaches, which he attributed to his gear. The Veteran wrote that he recalled many nights on perimeter security in his bunker, and, on occasion, “trading shots” with suspected enemy positions. He also described an incident during which he sank down to his thighs in a rice field and struggled to make his way through. According to a December 2008 VA primary care note, the Veteran strained his back in or around November 2008 after jumping down about three feet and that his symptoms were worse after a plane flight. A December 2008 MRI showed a tethered distal spinal cord extending up to L5, in addition to degenerative spondylotic changes. A November 2009 consultation report from Dr. G. notes that the Veteran had a prior history of spina bifida and that he apparently had surgery as a child. According to the report, the Veteran described that he was generally compensated and had done well over the course of the years, except for mild bladder and bowel dysfunction with bowel constipation and mild bladder retention. It was noted that in October 2008, the Veteran injured his back when jumping down while working. This was described as a significant jolting movement to the low back, and the Veteran reported pain and discomfort in the lumbo-sacral region at that time. He did “fairly well” until January 2009, when symptomatology apparently worsened, including increased lumbosacral spine pain that was radiating down the left lower extremity. Dr. G. noted that the Veteran apparently injured his back and now had a significant increase in prior mild symptomatology. The problem lists in VA primary care notes dated since December 2009 note low back pain with history of spina bifida and that the Veteran has had a flare-up since an injury in November 2008. Private medical records from D. H. indicate that the Veteran underwent a lumbar spine laminectomy, facetectomy, and discectomy in April 2010. The operative report provides that the Veteran had a known history of spina bifida, that he had been active, and that over one year ago, he jumped off the back of a pickup truck and had the immediate onset of numbness and weakness in his legs, in addition to some bowel and bladder dysfunction. It was noted that the numbness was somewhat persistent, but that the leg weakness had improved. His bowel and bladder dysfunction returned to its usual baseline pre-injury level of dysfunction. The Veteran was afforded a VA back examination in June 2010. The examiner noted the Veteran’s history of tethered spinal cord and spina bifida, including his surgery at the age of five. The examiner detailed the Veteran’s reported history of in-service bowel and bladder problems, in addition to the fact that he reported seeing a urologist over the years for bladder issues. It was noted that since the 2008 pickup truck accident, the Veteran required self-catheterization three to four times a day. The Veteran complained of daily low back pain radiating to his bilateral legs with constant burning at the feet. The examiner reviewed the Veteran’s service treatment records and noted that spina bifida was confirmed based on X-ray and was noted on the Veteran’s induction examination report. The examiner highlighted that during service, the Veteran was seen on multiple occasions for various issues, including penile lesion, right hand burn/rash, nervousness, poor sleep, mild wheezing, urethritis, and tension headaches. The examiner also discussed medical treatment records, such as the November 2009 report from Dr. G., which documented trauma in October 2008 with acute numbness and weakness in the legs, in addition to the Veteran’s April 2010 back surgery. The examiner opined that there was no objective data to support the contention that the Veteran’s spinal condition increased in disability during service beyond the natural progression of the disease. There was no data to substantiate any chronic spinal cord, headaches, bowel condition, or bladder condition from his STRs. Based on a review of the STRs, there was no objective data to support aggravation of headaches, bowel, or bladder conditions during service, nor were there post-service medical documents to substantiate any chronic nature of headaches, bowel, or bladder conditions. According to the examiner, the Veteran’s recent decline with respect to his back, in addition to his claimed headaches, bowel, and bladder conditions, were related to recent non-service related trauma and not to any aggravation of any congenital spinal condition. The examiner addressed the 2006 positive etiology opinion and highlighted that the treating physician did not have access to the Veteran’s STRs and that the opinion was based solely on subjective reporting by the Veteran. The examiner wrote that the STRs did not support the contention that the Veteran’s spinal condition increased in disability during service. In a December 2010 statement, the Veteran wrote that with respect to his back and leg pain, he recalled an incident that occurred one night while on the defensive perimeter. Specifically, while avoiding being hit by small arms fire, he fell six to seven feet from the top of a bunker. In December 2010, the Veteran submitted a lay statement from B.T., who was stationed at Cat Lai with the Veteran in 1967. According to B.T., the Veteran recently contacted him to ask if he remembered an incident during which the Veteran was hurt from a fall while trying to avoid enemy fire. B.T. wrote that as best as he could remember, the Veteran was injured when he fell trying to get back into a bunker. B.T. was not present at the perimeter location that night, but he did reportedly remember the Veteran telling him what had happened a few days later. According to B.T., he remembered the conversation taking place because he had not seen the Veteran in Cat Lai for “a while,” and the Veteran told him that he was in the hospital for a few days. In a December 2013 letter, Dr. B. wrote that he had evaluated the Veteran for his tethered spinal cord with neurogenic bladder and bowel. The Veteran provided Dr. B. with his history of surgery as an infant for his tethered cord and the fact that myelomeningocele was noted on his induction physical. Dr. B. wrote that it was his medical opinion that in all medical probability, the Veteran’s military service aggravated his tethered cord. The Veteran offered testimony at a DRO hearing in February 2014. The Veteran described an incident during service when he was coming back from the rifle range. He jumped out of a two-and-a-half-ton truck and felt a sharp pain in his lower back and left leg. He thought he pulled a muscle. The Veteran also reported an incident during which he noticed a very sharp pain in his back and left leg while attempting to pick up a light trailer by the tongue, which was stuck in the mud. The Veteran described an incident when he was carrying a radio in a rice field and sunk down to his thighs. When he bent over to try to pull his legs to move them, he felt a sharp pain in his lower back and noticed his legs becoming very weak. The Veteran also noted the reported bunker incident that took place during an attack. He described falling about ten feet onto his back and experiencing pain in his back and left leg. In a December 2014 VA neurology note, VA neurologist Dr. S.A. discussed the history of the Veteran’s condition. According to the neurologist, given the Veteran’s documented spina bifida at his pre-service physical, it was “somewhat surprising” that he was accepted for military service. The Veteran reported being asymptomatic prior to entering service and became aware of the complications of spina bifida only after he had been subjected to the rigors of military service. Dr. S.A. wrote that the Veteran mentioned many instances of injury during his tour of duty and that upon discharge, he was found to have a tethered spinal cord. The Veteran’s symptoms, then and now, were consistent with neurogenic claudication secondary to a tethered cord syndrome: a band-like tightness around the lower extremities, particularly in the calf muscles brought on by walking a short distance; numbness and weakness in the proximal lower extremities; and bowel and bladder issues. Symptoms usually improve with resting and forward-leaning posture. The Veteran specifically mentioned an incident during basic training, during which he jumped off of the back of a truck and felt a sharp, pulling pain in the lower back and an ache in the left leg. According to Dr. S.A., reflecting back now, it is reasonable to assume that the Veteran had stretched some nerve roots that were compressed due to spina bifida. The Veteran mentioned that during a prolonged forced march at night, he developed intense stomach pains and was told that he was impacted with stool and retaining urine in his bladder. Dr. S.A. assumed that the bowel and bladder issues could be blamed on the tethered spinal cord. The Veteran also mentioned an incident during which he was filling and hauling sandbags. The Veteran was “scrambling around” as he and other service members were being shot at, and he began to notice bowel and bladder problems, including constipation and burning bladder pain. Dr. S.A. wrote that the Veteran began having difficulty lifting and moving equipment with the further advance of back and leg problems. The Veteran described many instances of sudden muscle spasms and muscle/joint aches. For example, the Veteran noted an incident during which he tried to lift the tongue of a light trailer that was stuck, and he heard a “snap” coming from his back. It reportedly took many days to recover. According to Dr. S.A., the Veteran’s neurogenic claudication has been of varying intensities with occasional very severe flare-ups. Dr. S.A. noted the incident in the rice paddies, where the Veteran’s legs reportedly froze up and felt numb. The Veteran also noticed a severe band-like pain from the lower back radiating across the abdomen. The Veteran had to be pulled out of the mud by others in his platoon because he could not extricate himself under his own power. Dr. S.A. noted that the Veteran also suffered additional injuries in combat, such as severe leg bleeding from a sharp object while attempting to seek safety in a bunker during heavy incoming fire. Dr. S.A. opined that, to this day, the Veteran continues to suffer from those symptoms and chronic pain issues resulting most likely from complications of spina bifida, which were not recognized and therefore undiagnosed while in the Army. Based on the Veteran’s medical history, it seemed unreasonable that the Veteran was enlisted during a time of war. Based on the noted case history, Dr. S.A. believed that the Veteran’s spinal condition was asymptomatic prior to service and that his current spine condition was more likely than not related to the physical traumas of military service. A February 2016 neurology note from Dr. S.A. essentially includes the same information regarding the Veteran’s low back condition as the December 2014 neurology note. Dr. S.A. noted that the Veteran’s spinal condition was asymptomatic prior to service and that it was more likely than not that his current spine condition was a reflection of the worsening of his baseline spina bifida due to the physical strain of military service. Next, the Court’s April 2019 Memorandum Decision (MemDec) shows in part, “Appellant argues the Board erred in relying on a June 2010 VA examination to deny his claim for service connection for a lumbar spine disability. He contends that the examination was inadequate because the examiner attributed all of his symptoms to a 2008 injury, instead of considering his in-service symptoms. He also argues that the Board failed to take into account his bowel and bladder symptoms, which are related to his spina bifida and may indicate additional disability.” The Court went on to hold that the Board’s December 2017 decision “failed to account for the fact that those continued symptoms could have indicated an additional disability superimposed on his spina bifida. Additionally, the Board relied on the June 2010 VA examination, which failed to discuss those symptoms and their relationship to spina bifida.” Per the October 2019 Board remand, the Veteran underwent a VA examination in January 2020. The examiner noted that in addition to the Veteran’s claimed spina bifida, the Veteran also had an unrelated intercurrent injury to his spine which likely resulted in degenerative arthritis of the spine, intervertebral disc syndrome and spinal stenosis which required a spinal fusion and laminectomy in 2008/9. The examiner found that these were unlikely related to the Veteran’s claimed spina bifida condition. The Veteran reported that upon enlistment he was unaware that he had surgery for spina bifida as an infant. During service, he had low back pain, leg pain and bowel problems as well as urinary infections. The examiner noted that tethered cord syndrome symptoms in adults include severe back and lower leg pain, progressive sensory and motor deficits and bladder and bowel dysfunction. The examiner indicated that spina bifida was noted at the time of the Veteran’s enlistment was unlikely related to or aggravated by the Veteran’s service. The Veteran’s status at the time of enlistment also likely included tethered cord syndrome which was unknown/unidentified at the time as more recent MRI tests were not available at the time of service or available until the 1970s. The Veteran also had an intercurrent lumbar spine herniation in October 2008 that was likely the result of a 2008 post service injury that was documented in the records. The examiner found that the evidence did not indicate a superimposed disease or injury in connection with the congenital defect during service. The Veteran’s described symptoms are consistent with the known associated potential symptoms of this congenital condition (spina bifida/tethered cord). The evidence did not support a permanent aggravation of the congenital preexisting spina bifida with tethered cord. The increased symptoms over the past 10 years as likely as not represented the natural history of the spina bifida with associated tethered cord as well as the intercurrent 2008 back injury/spinal fusion. The examiner noted that bladder and bowel symptoms were often associated at the baseline of tethered cord and the Veteran’s medical history revealed bladder and bowel symptoms that occurred as a child preservice due to his spina bifida. The Veteran’s back and leg pain as likely as not occurred in service as well as post-discharge in the setting of provoking activities that caused stretching of the tethered cord as medically expected. However, a review of the records does not support a permanent aggravation/worsening of these symptoms as a result of his service. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for a lumbar disability is not warranted. As an initial matter, the Board notes that while the Veteran’s low back condition is claimed as spina bifida/Chiari malformation, the Board’s discussion below will be limited to spina bifida. While there is medical evidence demonstrating a history of Chiari malformation, this condition involves herniation of the brain into the upper spine, and based on a review of the Veteran’s medical records, the Chiari malformation is associated with headaches as opposed to low back symptomatology. See Dorland’s Illustrated Medical Dictionary 1098 (32d ed. 2012) (defining Chiari malformation). As the Chiari malformation does not appear to relate to low back symptomatology, and given that there is no indication that the Veteran seeks to reopen the claim for service connection for headaches that was denied by the Board in June 2011, Chiari malformation will not be further addressed, and there is no basis for referral to the AOJ. The Veteran’s spina bifida is a congenital or developmental defect. In the absence of a superimposed disease or injury, service connection cannot be granted for congenital or developmental defects, as they are not considered diseases or injuries within the meaning of applicable laws and regulations relating to service connection. See 38 C.F.R. §§ 3.303 (c), 4.9; VAOPGCPREC 82-90. Particularly when relying on the January 2020 VA examination report, the competent and credible evidence of record weighs against a finding that any additional disability resulted from the Veteran’s spina bifida defect being subject to, or aggravated by, an in-service superimposed disease or injury. Thus, service connection is not warranted. Notably, the January 2020 VA examiner indicated that spina bifida was noted at the time of the Veteran’s enlistment was unlikely related to or aggravated by the Veteran’s service. The June 2010 examiner also opined that the Veteran’s spinal cord condition did not undergo an increase in disability during active service beyond its natural progression. The examiner stressed that there was no objective data to support the Veteran’s contention regarding worsening, or to substantiate any chronic spinal cord condition during service. Additionally, the Veteran’s service treatment records did not document chronic or aggravated headaches, bowel, or bladder conditions that would substantiate his claim regarding his low back. Instead, the November 2010 and January 2020 VA examiners found that recent back-related decline was due to the October 2008 pickup truck injury, and not to any in-service aggravation of any congenital spinal condition. In providing his opinion, the January 2020 VA examiner relied on service treatment records, other pertinent medical records, the Veteran’s reported symptomatology, and his medical expertise. As such, the examiner’s opinion is thorough and highly probative. See, e.g., Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 300-01 (2008). The Veteran’s service treatment records also show no treatment for back-related complaints. Moreover, it is particularly compelling that at his October 1967 separation examination, the Veteran denied any musculoskeletal, rectal, or urinary symptoms. In this regard, the Board acknowledges that the Veteran’s attorney has asserted that the October 1967 separation documents are falsified. However, the fact that the separation physical documents are included in the claims file carries more weight than a largely unsupported assertion that the Veteran did not undergo an examination at separation. See Curry v. Brown, 7 Vet. App. 59, 67-68 (1994) (providing that contemporaneous evidence can have greater probative value than inconsistent testimony provided at a later date). Moreover, the fact that the October 1967 report of medical history is signed by the Veteran weighs significantly against the assertion that the Veteran did not undergo a separation examination. Accordingly, the Board finds that the separation examination report is authentic and based on findings made on examination. There is also no documentation of back-related complaints prior to November 2003, which also weighs against a finding of continued, worsening symptoms since service, particularly where, as here, there are multiple medical records dating as far back as 1978. The June 2010 VA examiner’s opinion that the Veteran’s recent decline was due to non-service connected trauma to the spine that occurred in October 2008 is also bolstered by the November 2009 consultation report from Dr. G. Of note, Dr. G. noted that with respect to the Veteran’s history of spina bifida, he was “generally well compensated” and “had done well over the course of the years, except for mild bladder and bowel dysfunction.” The Veteran then injured his back in October 2008 while working, described radiating pain and discomfort at that time, and subsequently began to note paresthesias and worsening of mild bowel and bladder problems. Dr. G. wrote that the Veteran “apparently injured [his] back and now has a significant increase in prior mild symptomatology.” By writing that there had been no prior issues other than mild bladder and bowel dysfunction, and by linking the Veteran’s back pain to the October 2008 injury, Dr. G.’s report weighs against a finding of continuity of symptomatology suggestive of additional disability due to superimposed in-service disease or injury, and it supports a finding that the Veteran’s decline and current symptomatology are due to the non-service related injury that occurred in or around October or November 2008. The Board notes that the question of whether the Veteran’s spina bifida was aggravated during service will turn on the conflicting medical opinions of record addressing the possibility of such a relationship. The Board may favor the opinion of one competent medical professional over that of another so long as an adequate statement of reasons and bases is provided. See Owens v. Brown, 7 Vet. App. 429, 433 (1995). An evaluation of the probative value of medical opinion evidence is based on the medical expert’s personal examination of the patient, the examiner’s knowledge and skill in analyzing the data, and the medical conclusion reached. The credibility and weight to be attached to such opinions are within the province of the Board as adjudicators. Guerrieri v. Brown, 4 Vet. App. 467 (1993). Greater weight may be placed on one physician’s opinion over another depending on factors such as reasoning employed by the physicians and whether or not and the extent to which they reviewed prior clinical records and other evidence. Gabrielson v. Brown, 7 Vet. App. 36 (1994). The probative value of a medical opinion is generally based on the scope of the examination or review, as well as the relative merits of the expert’s qualifications and analytical findings, and the probative weight of a medical opinion may be reduced if the examiner fails to explain the basis for an opinion. Sklar v. Brown, 5 Vet. App. 140 (1993). The Board again acknowledges that there are several opinions of record providing that the Veteran’s spina bifida was aggravated during service. However, the Board affords, at most, limited probative value to these opinions because they contain little to no rationale, such as the December 2013 opinion from Dr. B., or they are based primarily, if not entirely, on the Veteran’s subjective reports. This is particularly is problematic where, as here, the record raises issues concerning the credibility of the Veteran’s reports. See, e.g., Monzingo v. Shinseki, 26 Vet. App. 97, 107 (2012) (providing that a medical opinion based on inaccurate factual premise has no probative value). For instance, the May 2006 opinion from C.N.B.S. is based upon the Veteran’s reported history of a progression of symptoms, such as chronic low back pain, since service. However, in this regard, the Board finds significant that the Veteran denied any history of musculoskeletal symptoms at his separation examination, and the examining physician did not note any back-related issues. See Curry, 7 Vet. App. at 67-68. Additionally, despite the fact that the record includes post-service medical records from various providers dating back to 1978, there is no indication of treatment for, or complaints related to, low back pain until November 2003, over thirty-five years after the Veteran’s separation from service. See id. Moreover, Dr. G.’s November 2009 consultation report indicates that, except for mild bladder and bowel dysfunction, there were no significant low back issues until after the Veteran’s October 2008 injury. Given that there is no indication that the May 2006 opinion was based on consideration of relevant prior medical records, and that the reported medical history upon which the opinion is based is contradicted by other, objective evidence of record, the Board affords, at most, limited probative value to the May 2006 opinion. See Guerrieri v. Brown, 4 Vet. App. 467, 470-71 (1993); see also Monzingo, 26 Vet. App. at 107. As for the December 2014 and February 2016 VA neurology notes, Dr. A.’s opinion that the Veteran’s current spine condition reflects a worsening of his spina bifida during service, relies primarily, if not entirely, on reports from the Veteran regarding multiple instances of injury during his active military service. There is no indication that Dr. A. reviewed the Veteran’s service treatment records or post-service private treatment records, or that he considered the October 2008 pickup truck-related injury. Further, while Dr. A. relied on reported injuries, such as a pulling pain in the back after jumping off the back of a truck, the Board finds significant that the record contains no indication of such incident prior to the Veteran’s February 2014 DRO hearing, despite the fact that the Veteran had a DRO hearing in April 2006, presented for a VA examination in June 2010, and submitted statements prior to the February 2014 DRO hearing. In this regard, the Board finds particularly compelling that, at his April 2006 DRO hearing, the Veteran was asked twice about what he felt aggravated his spina bifida during service, and his response was that spinal compression was caused by basic training, including marching and exercise, and/or by performing duties such as carrying and setting up heavy items. Crucially, however, the Veteran did not note any in-service truck-related incident. Moreover, while Dr. A.’s opinion relies on various reports of symptomatology during service, such as muscle spasms, muscle and joint aches, and neurogenic claudication, these reported symptoms are countered by the fact that the record contains no STRs indicating back-related symptoms, the Veteran denied any history of back-related symptoms at his separation examination, and there were no back-related issues noted in his separation examination report. Thus, the record reflects that Dr. A. relied on representations from the Veteran that are inconsistent with evidence of record, to include contemporaneous medical evidence and prior representations from the Veteran himself. See Buchanan v. Nicholson, 451 F.3d 1331, 1337 (Fed. Cir. 2006) (providing that the Board, as fact finder, is obligated to, and fully justified in, determining whether lay evidence is credible in and of itself, i.e., because of possible bias, conflicting statements, etc.); see also Caluza, 7 Vet. App. at 511-12 (noting that in determining the credibility of lay witnesses, the Board may consider factors such as inconsistencies among lay statements); Curry, 7 Vet. App. at 67-68. As such, the Board affords, at most, limited probative value to Dr. A.’s opinion. See Monzingo, 26 Vet. App. at 107 ; Guerrieri, 4 Vet. App. at 470-71. As noted above, because it is a congenital defect the Veteran’s spina bifida may not be service connected. See 38 C.F.R. §§ 3.303 (c), 4.9 (congenital or developmental defects are not diseases or injuries within the meaning of applicable legislation for disability compensation purposes). However, the Board has considered whether service connection may be available for a disease or injury that was superimposed on his congenital spina bifida, or which was otherwise incurred during service. See Carpenter v. Brown, 8 Vet. App. 240, 245 (1995); VAOPGCPREC 82-90. Service connection may not be granted for congenital defects, such as the Veteran’s spina bifida, on a direct basis, and the evidence is insufficient to show that the Veteran’s congenital spina bifida was subject to a superimposed disease or injury as the result of his active military service. See VAOPGCPREC 82-90. As noted in the April 2019 Memorandum Decision, the Veteran argues that the Board in its December 2017 decision failed to take into account his bowel and bladder symptoms, which are related to his spina bifida and may indicate additional disability.” The Court found that the Board’s December 2017 decision “failed to account for the fact that those continued symptoms could have indicated an additional disability superimposed on his spina bifida. Additionally, the Board relied on the June 2010 VA examination, which failed to discuss those symptoms and their relationship to spina bifida.” As a result, per the October 2019 Board instructions and in conjunction with the April 2019 Memorandum Decision, the Veteran underwent a VA examination in January 2020 to address whether the Veteran’s congenital spina bifida underwent a superimposed disease or injury as the result of active service. Notably, the January 2020 VA examiner specifically found that the evidence did not indicate a superimposed disease or injury in connection with the congenital defect during service. The examiner noted that during service, the Veteran had low back pain, leg pain and bowel problems as well as urinary infections while also noting that tethered cord syndrome symptoms in adults include severe back and lower leg pain, progressive sensory and motor deficits and bladder and bowel dysfunction. The examiner indicated that the Veteran’s described symptoms were consistent with the known associated potential symptoms of this congenital condition (spina bifida/tethered cord) and that the evidence did not support a permanent aggravation of the congenital preexisting spina bifida with tethered cord. The examiner also noted that the increased symptoms over the past 10 years as likely as not represented the natural history of the spina bifida with associated tethered cord as well as the intercurrent 2008 back injury/spinal fusion. Regarding the Veteran’s bowel and bladder symptoms and their relationship to spina bifida, the examiner noted that bladder and bowel symptoms were often associated at the baseline of tethered cord and the Veteran’s medical history revealed bladder and bowel symptoms that occurred as a child preservice due to his spina bifida. The examiner noted that while the Veteran’s back and leg pain as likely as not occurred in service as well as post-discharge in the setting of provoking activities that caused stretching of the tethered cord as medically expected, a review of the records did not support a permanent aggravation/worsening of these symptoms as a result of his service. Therefore, the Board finds that the Veteran’s congenital spina bifida underwent no superimposed disease or injury as the result of active service and the claim for service connection on this basis is denied. As the positive opinions of record are significantly outweighed by the June 2010 and January 2020 VA examiners opinions, the preponderance of the evidence is against a finding that the Veteran’s spina bifida was subject to, or aggravated by, a superimposed disease or injury during service that resulted in additional disability. Thus, service connection cannot be granted. See 38 C.F.R. §§ 3.303 (c), 4.9; VAOPGCPREC 82-90. In reaching this conclusion, the Board has considered the Veteran’s attorney’s contention that 38 U.S.C. § 1154 (b) applies to the instant claim. In this regard, the Board notes that neither the Veteran’s DD-214 nor his personnel records confirm that he engaged in combat. However, the RO has conceded that the Veteran served in combat and the Board will apply the applicable presumption. See August 2014 JSRRC Memo, April 2014 VAX for PTSD; June 2016 rating decision. VA shall accept as sufficient proof of service connection satisfactory lay or other evidence of service incurrence or aggravation, if the evidence is consistent with the circumstances, conditions, or hardships of such service. Although it has been conceded that the Veteran served in combat by the RO, the Board does not find his reports of how he injured his back during combat situations to be credible. In other words, the Board does not find his reports to be satisfactory lay evidence of service incurrence or aggravation of his pre-existing spina bifida. In this regard, the Veteran has not proffered satisfactory lay or other evidence of combat-related aggravation of his spina bifida. Based on the Veteran’s February 2014 hearing testimony, it appears that the claimed combat injury occurred when the Veteran fell from an elevated bunker during an enemy attack. However, prior to December 2010 statements from the Veteran and B.T., the record contains no indication of this claimed injury, even though the Veteran had a DRO hearing in April 2006, presented for a VA examination in June 2010, and submitted statements prior to December 2010. Significantly, the Veteran wrote about “trading shots” with suspected enemy positions from his bunker in June 2006, but made no notation regarding any injury associated with this activity. Further, at his April 2006 DRO hearing, the Veteran did not report any injury related to enemy attacks or a fall from the top of a bunker. Instead, when asked about factors that might have aggravated his spina bifida during service, the Veteran maintained that there was spinal compression caused by basic training, including marching and exercise, and/or by performing duties such as carrying and setting up heavy items. As for the December 2010 statement from B.T., B.T. was not present at the perimeter on the night of the alleged incident, his memory of the reported injury is vague, and his memory of his conversation with the Veteran reflects an inconsistency with the Veteran’s service treatment records. Specifically, while B.T. recalled the Veteran telling him that he was hospitalized for a few days, there is no indication of such hospitalization in the Veteran’s service treatment records. The Board also finds significant that, in providing that the Veteran suffered combat injuries during service, neurologist Dr. A. only noted leg bleeding that resulted from an attempt to seek safety in a bunker, in addition to significant hearing loss. Dr. A. did not mention any back-related injury that occurred during combat or as a result of falling from a bunker. Accordingly, these lay reports are not credible or are otherwise unreliable. As such, they do not constitute satisfactory lay or other evidence of in-service aggravation of the Veteran’s spina bifida. See Buchanan, 451 F.3d at 1337; Collette, 82 F.3d at 393. Therefore, 38 U.S.C. § 1154 (b) and its implementing regulation, 38 C.F.R. § 3.304 (d), are inapplicable. See Caluza, 7 Vet. App. at 507. The Board notes the Veteran’s contentions regarding the etiology of his claimed lumbar spine disability. To the extent that the Veteran himself contends that a medical relationship exists between his claimed current disability and service, the Board acknowledges that the Veteran is competent to testify as to his observations. Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). Furthermore, lay witnesses may, in some circumstances, opine on questions of diagnosis and etiology. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009) (finding that the Board’s categorical statement that “a valid medical opinion” was required to establish nexus, and that a layperson was “not competent” to provide testimony as to nexus because she was a layperson, conflicts with Jandreau). In the instant case, however, the Board finds that a lumbar spine disability is not a disability subject to lay diagnosis as this diagnosis requires medical training. More significantly, the Veteran and his representative do not have the medical expertise to provide an opinion regarding the claimed a lumbar spine disability etiology. Specifically, 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. West, 12 Vet. App. 460, 465 (1999). Additionally, the January 2020 VA examiner provided detailed rationales in support of her opinions and cited to the relevant evidence. For this reason, the VA examiner’s opinions are the most probative evidence of record. See Prejean v. West, 13 Vet. App. 444, 448-9 (2000) (noting that a factor for assessing the probative value of a medical opinion includes the thoroughness and detail of the opinion). In sum, for the reasons and bases expressed above the Board finds that the preponderance of the evidence is against the Veteran’s claims of entitlement to service connection for a lumbar spine disability. The benefit-of-the-doubt rule does not apply, and the claim must be denied. 38 U.S.C. § 5107(b). MICHAEL LANE Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board James A. DeFrank, 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.