Citation Nr: 1217543 Decision Date: 05/16/12 Archive Date: 05/24/12 DOCKET NO. 99-22 327A ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Newark, New Jersey THE ISSUES 1. Entitlement to service connection for residuals of infectious mononucleosis. 2. Entitlement to service connection for chronic liver disease, to include as due to herbicide exposure. REPRESENTATION Appellant represented by: Vietnam Veterans of America WITNESSES AT HEARING ON APPEAL Appellant and E.N. ATTORNEY FOR THE BOARD S. Mishalanie, Counsel INTRODUCTION The Veteran had active service from September 1968 to September 1971. This matter came before the Board of Veterans' Appeals (Board) on appeal from a decision of July 1997 by the Department of Veterans Affairs (VA) Regional Office (RO) in Newark, New Jersey. A Travel Board hearing in front of the undersigned Veterans Law Judge was held in September 2002. A transcript of the hearing has been associated with the claim file. This case was previously before the Board. In October 2003, the Board remanded the matters to the Agency of Original Jurisdiction (AOJ) for additional development. In December 2005, the Board reopened the claim for entitlement to service connection for residuals of mononucleosis and denied the claim on the merits. It also denied service connection for chronic liver disease. The Veteran appealed to the Court of Appeals for Veterans Claims (Court). In a February 2008 memorandum decision, the Court vacated the Board's December 2005 decision and remanded the appeal for further proceedings. In June 2008, the Board denied the Veteran's claims. In August 2009, pursuant to a Joint Motion for Remand, the Court vacated the Board's denial and remanded the appeal to the Board for additional development. In July 2010, the Board requested an independent medical expert opinion (IME). In December 2010, the Board remanded the claims to the AOJ for issuance of a supplemental statement of the case (SSOC). FINDINGS OF FACT 1. No residuals of infectious mononucleosis are shown. 2. The evidence shows that the Veteran did not have liver disease during active service or within one year of separation; and that his cryptogenic cirrhosis is not otherwise related to active service, including as a residual of infectious mononucleosis or exposure to Agent Orange. CONCLUSIONS OF LAW 1. Infectious mononucleosis residuals were not incurred in or aggravated by service. 38 U.S.C.A. § 1110 (West 2002); 38 C.F.R. § 3.303 (2011). 2. A liver disability, diagnosed as cryptogenic cirrhosis, was not incurred in or aggravated by service and may not be presumed to have been incurred therein. 38 U.S.C.A. §§ 1101, 1110, 1112, 1113 (West 2002); 38 C.F.R. § 3.303, 3.307, 3.309 (2011). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS Duties to Notify and Assist The Veterans Claims Assistance Act of 2000 (VCAA), codified in pertinent part at 38 U.S.C.A. §§ 5103, 5103A (West 2002 & Supp. 2011), and the pertinent implementing regulation, codified at 38 C.F.R. § 3.159 (2011), provide that VA will assist a claimant in obtaining evidence necessary to substantiate a claim but is not required to provide assistance to a claimant if there is no reasonable possibility that such assistance would aid in substantiating the claim. As part of the notice, VA is to specifically inform the claimant and the claimant's representative, if any, of which portion, if any, of the evidence is to be provided by the claimant and which part, if any, VA will attempt to obtain on behalf of the claimant. Additionally, the United States Court of Appeals for Veterans Claims (Court) has held that the plain language of 38 U.S.C.A. § 5103(a) (West 2002) requires that notice to a claimant pursuant to the VCAA be provided "at the time" that, or "immediately after," VA receives a complete or substantially complete application for VA-administered benefits. Pelegrini v. Prinicpi, 18 Vet. App. 112, 119 (2004). The timing requirement enunciated in Pelegrini applies equally to the initial disability-rating and effective-date elements of a service connection claim. Dingess v. Nicholson, 19 Vet. App. 473 (2006). In the present case, the Veteran's claim was received prior to the enactment of the VCAA. A letter dated in April 2001 explained the VCAA. The Veteran was asked to advise VA if there were outstanding medical records showing that the claimed disabilities were related to service. He was told that the evidence should show that the claimed condition existed and there was a nexus to service, or that it was related to a condition for which service connection had already been established. He was also advised that he could submit evidence of continuity and chronicity of the claimed condition. The letter described how VA would assist the veteran in obtaining evidence. He was told that VA had requested records from the Social Security Administration (SSA). A March 2006 letter advised the Veteran of the manner in which VA determines disability ratings and effective dates. The Board finds that any defect with respect to the timing of the VCAA notice requirement was harmless error. The content of the notice provided to the Veteran fully complied with the requirements of 38 U.S.C.A. § 5103(a) and 38 C.F.R. § 3.159(b) regarding VA's duty to notify. The Veteran has been provided with every opportunity to submit evidence and argument in support of the claim and to respond to VA notices. Although the Veteran received inadequate preadjudicatory notice, and that error is presumed prejudicial, the record reflects that he was provided with a meaningful opportunity such that the preadjudicatory notice error did not affect the essential fairness of the adjudication now on appeal. The Board finds that the purpose behind the notice requirement has been satisfied because the Veteran has been afforded a meaningful opportunity to participate effectively in the processing of his claims. With respect to VA's duty to assist, identified treatment records have been obtained and associated with the record. VA examinations have been conducted, and opinions requested. Records have been obtained from SSA. The Veteran was afforded the opportunity to testify before the undersigned. During the hearing, the undersigned discussed with the Veteran and elicited information with regard to his claims. This action supplements VA's compliance with the VCAA and satisfies 38 C.F.R. § 3.103. The Veteran has not identified any additional evidence or information which could be obtained to substantiate the claim. The Board is also unaware of any such outstanding evidence or information. Therefore, the Board is also satisfied that the RO has complied with the duty to assist requirements of the VCAA and the implementing regulations. For the foregoing reasons, it is not prejudicial to the Veteran for the Board to proceed to a final decision in this appeal. Governing Statutes 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.A. § 1110; 38 C.F.R. § 3.303(a). Establishing service connection generally 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. Holton v. Shinseki, 557 F.3d 1362, 1366 (Fed. Cir. 2009); 38 C.F.R. § 3.303(a). Under 38 C.F.R. § 3.303(b), an alternative method of establishing the second and third elements is through a demonstration of continuity of symptomatology. See Barr v. Nicholson, 21 Vet. App. 303, 307 (2007). A claimant can establish continuity of symptomatology with competent evidence showing: (1) that a condition was "noted" during service; (2) post-service continuity of the same symptomatology; and (3) a nexus between a current disability and the post-service symptomatology. Savage v. Gober, 10 Vet. App. 488, 495-96 (1997); 38 C.F.R. § 3.303(b). Service connection may also be granted for any disease initially diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). If a veteran was exposed to an herbicide agent during active military, naval, or air service, certain diseases shall be service-connected if the requirements of 38 C.F.R. § 3.307(a)(6) are met, even if there is no record of such disease during service, provided further that the rebuttable presumption provisions of 38 C.F.R. § 3.307(d) are also satisfied. 38 C.F.R. § 3.309(e) . Veterans who 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 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 C.F.R. § 3.307 . Service connection on a presumptive basis for exposure to herbicides in Vietnam is limited to the following diagnoses: non-Hodgkin's lymphoma, soft-tissue sarcoma, chloracne or other acneform disease consistent with chloracne, Hodgkin's disease, porphyria cutanea tarda, respiratory cancers (cancer of the lung, bronchus, larynx, or trachea), multiple myeloma, Type 2 diabetes, acute and subacute peripheral neuropathy, and prostate cancer. See 38 U.S.C.A. § 1116(a)(2) (West 2002); 38 C.F.R. § 3.309(e) (2011). VA has determined that a presumption of service connection based on exposure to herbicides used in the Republic of Vietnam during the Vietnam era is not warranted for any condition for which VA has not specifically determined a presumption of service connection is warranted. See 75 Fed. Reg. 81332 - 81335 (Dec. 10, 2010); see also 68 Fed. Reg. 27630-27641 (May 20, 2003); 67 Fed. Reg. 42600 (June 24, 2002); 66 Fed. Reg. 2376 (Jan. 11, 2001); 64 Fed. Reg. 59232 (November 2, 1999). The United States Court of Appeals for the Federal Circuit (Federal Circuit) has held that when a claimed disorder is not included as a presumptive disorder direct service connection may nevertheless be established by evidence demonstrating that the disease was in fact "incurred" during service. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). In rendering a decision on appeal, the Board must analyze the credibility and probative value of the evidence, 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. See Gabrielson v. Brown, 7 Vet. App. 36, 39-40 (1994); Gilbert v. Derwinski, 1 Vet. App. 49, 57 (1990). 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"). When there is an approximate balance of positive and negative 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.A. § 5107(b) (West 2002). Analysis In this case, the Veteran asserts that the chronic liver disease that led to a liver transplantation had it onset in or is otherwise related to service. Specifically, the Veteran claims that his liver disease was caused either directly or indirectly by infectious mononucleosis, by hepatic processes, and/or by exposure to Agent Orange. The Veteran's service treatment records reflect that he complained of flu-like symptoms in January 1969. He was diagnosed with infectious mononucleosis and was hospitalized for approximately one month. In March 1969, he complained of a sore throat and it was noted that he had mononucleosis the previous month. CBC (complete blood count) and throat C&S (culturette and swab) were within normal limits. Transaminase (SGOT) levels were 41. In September 1969, SGOT levels were 88. It was noted that the Veteran had no complaints other than occasional right upper quadrant sharp pains of a few seconds duration. It was noted that he was quite concerned about this. It was noted that he was obese and his abdomen was within normal limits with no adenopathy. The following laboratory results were within normal limits: CBC, UA (urinary albumin), SGOT, BUN (blood urea nitrogen), and bilirubin. After receiving the results, the physician reassured the Veteran that there were no problems. The records do not indicate that there was any further treatment related to these complaints during service. The September 1971 separation examination report indicates that the Veteran's abdomen and viscera were normal. It was noted that the Veteran had infectious mononucleosis in 1969. The Veteran signed a statement indicating that he was in good health. In September 1971, the Veteran filed a claim for residuals of infectious mononucleosis with liver ailment. The report of an October 1971 VA examination reflects the Veteran's history of infectious mononucleosis with liver involvement but that it was "not found at this examination." Laboratory results showed that SGOT and bilirubin were within normal ranges. Private medical records from Dr. Chudzik dated from December 1992 to January 1997 reflect that the Veteran was primarily treated for essential hypertension and was advised to lose weight and follow a low-salt diet. In December 1992, laboratory results showed that SGOT was high at 83 and total bilirubin was 1.3. In October 1996, SGOT was 126 (normal range 1.00-45.0), total bilirubin was 4.98 (normal range 0.30-1.40), and direct bilirubin was 1.23 (normal range 0.00-0.20). An October 1996 CT scan of the abdomen and pelvis showed findings suggestive of cirrhosis. A VA general medical examination was carried out in March 1997. The Veteran's history was reviewed. The Veteran reported that he was awaiting a liver transplant. He also denied history of nausea, vomiting, or diarrhea, as well as fevers or chills. The diagnosis was end-stage liver disease, etiology unknown. In a May 1997 letter, Dr. Leevy, a private physician, stated that the Veteran was referred to New Jersey Medical School Liver Center after October 1996 blood work showed abnormal liver tests and anemia. Further test results were consistent with advanced liver disease. Hepatitis B and hepatitis C serologies were negative and a detailed medical history did not reveal significant alcohol intake or exposure to hepatoxic agents. Blood work for autoimmune causes and metabolic causes of cirrhosis were also negative. He was found to be an excellent candidate for liver transplant. A June 1997 operative report reflects that the Veteran underwent a liver transplant; the pre and post operative diagnosis was cryptogenic cirrhosis. In an April 1998 letter, Dr. Chudzik, the Veteran's primary care physician, stated that the Veteran had been under his care since December 1992. The physician expressed his belief that the Veteran's liver disease stemmed from earlier problems, first diagnosed in 1969. He noted that the Veteran's exposure to Agent Orange in Vietnam may have played a role in the development of liver disease. He stated that there may be a direct association between the Veteran's previous treatment for a liver disorder and infectious mononucleosis. He reiterated that there may be a direct relationship between the Veteran's previous liver disease and development of cryptogenic cirrhosis. A March 1999 opinion by two VA physicians, one of whom was a gastroenterologist, indicates that it was very unlikely that the Veteran's infectious mononucleosis of 1969 was the cause of his cirrhosis diagnosed in 1996. In a September 2002 letter, Dr. Chudzik reiterated his belief that the veteran's cirrhosis related to exposure to Agent Orange in service. In a September 2002 statement (VA Form 646), the Veteran's representative argued that Agent Orange caused the Veteran's liver disease. To support this argument, he attached a Physicians Desk Guide, which indicated that known risk factors for liver cancer include exposure to the carcinogens aflatoxin (produced by a fungus) and vinyl chloride (a chemical used to make PVC). The Guide does not mention any herbicide agents. In September 2002, the Veteran testified that he was hospitalized for infectious mononucleosis for 17 days. He said he then went to Germany and to Vietnam without having any further problems. He said that he did not have any problems for 25 years until he was diagnosed with cirrhosis. An additional opinion was rendered by a VA physician in March 2003. The author indicated that he had completely reviewed the Veteran's record and discussed the matter with a gastroenterologist. He concluded that it was not likely that the Veteran's current problems with liver disease had any relationship to his bout with infectious mononucleosis in service. He noted that there was documentation of mononucleosis, but that according to the literature he had reviewed, severe or permanent hepatic dysfunction is exceedingly rare as a sequelae of infectious mononucleosis. He indicated that while almost 90 percent of patients with mononucleosis experience mild elevation of hepatic transaminases, mononucleosis was not an etiology for cirrhosis of the liver. He concluded that the Veteran's liver disease did not have its onset in service. He pointed out that current medical records stated that the Veteran was diagnosed with cryptogenic cirrhosis, meaning that no etiology for the liver disease was found. He also concluded that it was not likely that the Veteran's liver disease was due to Agent Orange exposure, as there had been no scientific data to show any link between liver disease and such exposure. He again noted that the current records clearly indicated that the etiology of the Veteran's cirrhosis was unknown and that there was no scientific basis to attribute the liver condition to either infectious mononucleosis or exposure to Agent Orange. A September 2005 document from Dr. Bash, a neuro-radiologist, is styled as an independent medical evaluation. Dr. Bash indicated that he had reviewed the Veteran's claims file and medical records, including service medical records, post-service medical records, imaging and laboratory reports, other medical opinions, and medical literature. He opined that the Veteran's failed liver state was a result of "either/both an extension of some occult liver pathologic process that he had in service which raised his SGOT values or/and a result of this patients loss of hepatic reserve (hepatocytes) during service when he had months of elevated SGOT values." He maintained that the Veteran had several months of elevated SGOT, from March 1969 to September 1969. He stated that his review of the military records did not indicate a return to normal levels; however, he later stated that the October 1969 normal lab values and normal separation physical did not negate the fact that the Veteran likely had some degree of liver damage because those tests are insensitive to the level of damage that likely occurred from June to September 1969. He opined that the liver pathology in service was the precursor to his liver failure in 1997. In support of his conclusion, he stated that the Veteran developed a serious liver disease in service and had months of elevated liver enzymes consistent with an occult type of hepatitis. He indicated that the Veteran was likely exposed to some sort of hepatic cell damaging infection or toxin in service, and that hepatitis was known to cause cirrhosis. He also noted that it took years to decades to develop end-stage liver disease in some occult hepatic processes. With respect to the VA medical opinion, Dr. Bash stated that it was known that hepatitis and mononucleosis cause end-stage liver disease by way of cirrhosis, and that the examiner did not discuss how the loss of reserve liver function could cause the Veteran's liver to fail prematurely. He also indicated that the examiner did not provide any literature to support his opinion. In July 2010, the Board obtained an Independent Medical Opinion from Dr. Brown, an Assistant Professor at the University of Arkansas with a specialty in gastroenterology and hepatology. Dr. Brown stated that he reviewed the Veteran's entire medical record. Dr. Brown opined that it was less than 50 percent likely that the Veteran developed a chronic liver disease during the period of his military service. This conclusion was based on the lack of any medical documentation on record which would typically be present in the setting of a patient in the process of developing progressive liver failure such as persistent abnormal elevated liver enzymes (the above listed record shows normalization within a few months of his hospitalization in 1969), ascites, jaundice, or coagulopathy. Dr. Brown further pointed out that the elevated SGOT tests may be overblown if not put into perspective and that typically SGOT normal range is 30 to 40 IU/L. In the setting of severe or significant liver inflammation, the expected range of SGOT would be in the several hundred to thousand range. Dr. Brown also noted that slight elevations of SGOT occur in normal healthy individuals due to chemical and drug exposures that are not followed by evidence of liver injury. Dr. Brown also explained that infectious mononucleosis is caused by the Epstein-Barr virus (EBV) and that the vast majority of patients with EBV infection recover uneventfully. Modestly elevated liver enzymes are associated with EBV infection, but these are self-limited and resolve shortly after the infection. Dr. Brown noted that the Veteran's SGOT levels were normal in October 1969. No other medical conditions are commonly associated with previous EBV infection, and a complete literature search yielded no documented reports of EBV associated chronic liver disease or cirrhosis. Therefore, Dr. Brown concluded that it was less than 50 percent likely that the infectious mononucleosis that the Veteran suffered in service could be related to his chronic liver disease. Furthermore, Dr. Brown performed a comprehensive medical literature search for all studies evaluating the results of the herbicide agents found in Agent Orange. Dr. Brown noted that the National Academy of Sciences Institute of Medicine (IOM) 2008 Update concluded that "There was no evidence that Vietnam veterans are at greatly increased risk for serious liver disease, and the reports of increased of abnormal liver-function tests have been mixed. Although increased rates of gastrointestinal disease have not been reported, the possibility of a relationship between dioxin exposure and subtle alterations in the liver and lipid metabolism cannot be ruled out." Based on these findings, Dr. Brown concluded that he was comfortable saying that it was less than 50 percent likely that the Veteran's liver condition was caused by exposure to Agent Orange. Dr. Brown further stated that based on the limited medical records provided, he could find no other evidence of overt or occult liver disease present or originating during the patient's military service. Dr. Brown noted that this did not mean that an undocumented process could not have occurred, but that it seemed less than 50 percent likely to have. Finally, Dr. Brown stated that based on the evidence of record, it was very difficult to conclude what led the Veteran's liver failure. He noted that the two most common causes of liver cirrhosis are alcoholic liver disease and hepatitis C, which were both ruled out in this case. Dr. Brown noted that the proportion of patients with cryptogenic cirrhosis was declining, possibly because an increased number of patients may actually have nonalcoholic steatohepatitis (NASH). Obesity is reported in 69 to 100 percent of NASH cases. Dr. Brown pointed out that obesity was noted in many parts of the Veteran's medical record and in the absence of any other clinically relevant information; NASH related cirrhosis was the most likely cause of the Veteran's liver failure. In September 2010, Dr. Bash provided a rebuttal medical opinion. Dr. Bash stated that Dr. Brown's medical opinion was incorrect because it was likely based on an incomplete review of the record in that it did not address his September 2005 opinion or the opinions of Dr. Chudzik. Dr. Bash also stated that Dr. Brown did not discuss the concept of hepatic reserve function and that a patient can have significant decreased in hepatic function even in the face of normal routine liver function. Dr. Bash cited an excerpt describing how hepatic function reserve is assessed using the "Child-Pugh" classification, which is based on the grade of encephalopathy, bilirubin, albumin, and prothrombin time. It is noted that true quantitative measures of hepatocellular function, such as galactose elimination capacity, aminopyrine breath test, indocyanine green clearance, and hepatic clearance of amino acids are not available at most institutions but may be valuable indicators of limited hepatic reserve in some patients with nearly normal conventional liver function tests. The assessment of hepatocellular function is important to determine which patients are transplantation candidates. Dr. Bash reiterated that the liver damage that the Veteran had during service consumed a portion of his hepatic reserve function and that this loss in function made him susceptible to cirrhosis and the need for a transplant. Next, Dr. Bash cited information regarding Liver Function Tests. Liver Function Tests include tests for bilirubin and ammonia and tests to measure the levels of several enzymes. SGOT is an enzyme necessary for energy production and may be elevated in liver and heart disease. High levels may indicate liver cell damage, hepatitis, heart attack, heart failure, or gall stones. Bilirubin is a breakdown product of hemoglobin and elevated levels of indirect bilirubin are usually caused by liver cell dysfunction while elevations of direct bilirubin are typically caused by obstruction either within the liver or a source outside the liver. With respect to Agent Orange, Dr. Bash stated that Dr. Brown did not discuss the Veteran's liver cell loss due to Agent Orange in service, noting that the 2008 IOM report referenced a link between Agent Orange and liver enzyme elevation and that this should be a basis for service connection. Finally, Dr. Bash disagreed that the Veteran's liver disease was due to NASH and reiterated that Dr. Brown did not consider the effect of Agent Orange and hepatic cell death on the reserve liver function or the assertion that in-service hepatic problems lent assistance and made the Veteran more susceptible to cirrhosis. In October 2010, Dr. Chudzik also responded to Dr. Brown's opinion. He disagreed with the conclusion that NASH was the cause of the Veteran's cirrhosis because the Veteran only weighed 222 pounds at the time of his liver transplantation. He said that while the Veteran was overweight, he was not to the point where one might see NASH causing cirrhosis. Dr. Chuczik then reiterated his opinion that he believed "in the strongest terms" that the Veteran's cirrhosis was the result of Agent Orange in Vietnam. In this case, the Board acknowledges that competing competent evidence has been presented with respect to the matter at hand. It is the responsibility of the Board to assess the credibility and weight to be given the evidence. See Hayes v. Brown, 5 Vet. App. 60, 69-70 (1993) (citing Wood v. Derwinski, 1 Vet. App. 190, 192-93 (1992)). The probative value of medical evidence is based on the physician's knowledge and skill in analyzing the data, and the medical conclusion the physician reaches; as is true of any evidence, the credibility and weight to be attached to medical opinions are within the province of the Board. See Guerrieri v. Brown, 4 Vet. App. 467, 470-471 (1993). The Board may appropriately favor the opinion of one competent medical authority over another. See Owens v. Brown, 7 Vet. App. 429, 433 (1995). However, the Board may not reject medical opinions based on its own medical judgment. Obert v. Brown, 5 Vet. App. 30 (1993); see also Colvin v. Derwinski, 1 Vet. App 171 (1991). The weight of a medical opinion is diminished where that opinion is ambivalent, based on an inaccurate factual premise, based on an examination of limited scope, or where the basis for the opinion is not stated. See Reonal v. Brown, 5 Vet. App. 458, 461 (1993); Sklar v. Brown, 5 Vet. App. 140 (1993). In this case, the Board finds that Dr. Brown and VA examiners' opinions that the Veteran's chronic liver disease was less likely than not related to service are more probative. There are a number of reasons why the Board favors these opinions over those of Dr. Bash and Dr. Chudzik. First, the Board points out that the Dr. Brown specializes in gastroenterology and hepatology, the specific area of medicine at issue. Hence, he has the esoteric knowledge and expertise required to make the necessary determinations in this case. Cf. Black v. Brown, 10 Vet. App. 279 (1997). See also Guerrieri v. Brown, 4 Vet. App. 467, 470-71 (1993). On the other hand, Dr. Bash specializes in neuro-radiology and Dr. Chudzik is a primary care physician. While they presumably have some general medical knowledge of the issues at hand, they do not share the same level of expertise as Dr. Brown. Second, the opinions of Dr. Brown and the VA examiners that the Veteran's end-stage liver disease was not related to his in-service infectious mononucleosis and elevated SGOT levels are consistent with the contemporaneous medical record. Dr. Bash's opinion that the Veteran had significant liver damage or loss of hepatic function is not supported by the record. The Veteran had two elevated SGOT liver enzyme results, which Dr. Brown explained is typical of someone who has EBV (i.e., mononucleosis). However, there have been no documented cases of EBV causing chronic liver disease or cirrhosis and typically most acute symptoms of EBV infection resolve within a few weeks. Indeed, the Veteran testified that he had no further symptoms and lab results returned to normal in October 1969 and remained normal at the October 1971 VA examination. This does not support the premise that the Veteran sustained liver damage or a loss of hepatic function during service and this faulty premise is the basis of Dr. Bash's opinion, including his opinion that loss of hepatic function or reserves made the Veteran more susceptible to later developing cirrhosis. Dr. Bash brushes aside the Veteran's normal liver function tests of October 1969 and October 1971, suggesting that these tests were not sensitive enough to measure the Veteran's hepatic injury. But, as Dr. Brown acknowledged, even though it is possible that an undocumented process could have occurred in service, it is not probable in light of the medical record. Third, the opinion by Dr. Bash and Dr. Chudzik that exposure to Agent Orange caused elevated SGOT levels and/or the Veteran's chronic liver disease is not supported by the evidence of record or medical literature. To the extent that Dr. Bash notes that the 2008 IOM suggests a raise of liver enzymes in Veteran's exposed to Agent Orange, the Board points out that the Veteran's elevated SGOT levels occurred in early 1969, but he did not go to Vietnam until September 1970. The physicians provide no rationale to support their opinion that exposure to Agent Orange later caused the Veteran's end-stage liver disease. To this end, the most probative evidence of record is Dr. Bash's opinion, which is supported by the IOM report that there is no evidence of greatly increased risk of serious liver disease. While the report noted that subtle alterations in the liver metabolism could not be ruled out, this is not applicable to the present case. The Veteran sustained end-stage liver disease that necessitated liver transplantation, which in no way could be described as a subtle alteration in liver metabolism. The actual cause of the Veteran's cirrhosis and end-stage liver disease remains unknown. Dr. Brown suggests a likelihood of NASH for which obesity is a risk factor, noting that the Veteran was considered obese in much of the medical record. Dr. Chudzik degrees with this assessment, noting that the Veteran was overweight, but not so obese as suspect NASH. The Board points out, however, that the question of whether NASH caused the Veteran's liver disease is not determinative in this case. Here, the only relevant question is whether it is at least as likely as not that the Veteran's liver disease had its onset in or is otherwise related to service. For the reasons outlined above, the Board finds that the weight of the evidence is against such a finding. In its February 2008 memorandum decision, the Court questioned whether the Board's adopted the 'treating physician rule' to afford greater probative weight to the diagnosis of cryptogenic cirrhosis. The Board notes that we have not adopted a treating physician rule nor has the Board determined that a diagnosis must be made during service. Rather, all evidence is considered. Familiarity with a patient is evidence to be considered. Similarly, consistency of the evidence is a fact to be considered when balancing the evidence. As noted by the Court, the probative value of medical evidence is based on the medical expert's personal observation of the patient, the physician's knowledge and skill in analyzing the data, and the medical conclusion that the physician reaches. Guerrieri v. Brown, 4 Vet. App. 467, 471 (1993). Here, cryptogenic cirrhosis was diagnosed because the likely causes of cirrhosis (i.e., alcohol and hepatitis C) were ruled out. The diagnosis does not rule out the possibility of a link to service; however, for the reasons explained above, the most probative evidence is against such a relationship. In the August 2009 joint motion for remand, the parties found that the Board had an inadequate statement of reasons or bases for its decision to favor the March 2003 VA examination report over Dr. Bash's opinion. Specifically, the parties questioned the Board's conclusion that Dr. Bash's opinion was not consistent with the record because manifestations of liver damage were not found in service. The parties noted that the Board referred to no affirmative, competent evidence rebutting Dr. Bash's opinion that the in-service evidence elevated reflected liver damage that subsequent led to liver disease. In response, the Board points out the normal lab and liver function test results in October 1996 and November 1971 is affirmative evidence that the Veteran did not have significant liver damage. Significantly, bilirubin, which is noted in the literature cited by Dr. Bash to be an important diagnostic tool is determining liver cell dysfunction, was normal in October 1969 and November 1971. The Veteran had infectious mononucleosis, which temporarily raised SGOT liver enzymes levels. Dr. Brown could not find any medical literature documenting a case where infectious mononucleosis caused chronic liver disease or cirrhosis. Even if the elevated SGOT liver enzymes was not caused by infectious mononucleosis, as Dr. Bash suggests, the normal test results following the elevation of SGOT due to infection is affirmative evidence that the Veteran did not sustain liver damage in service. The clinical evidence is also consistent with this finding. Once the Veteran's SGOT levels returned to normal, he had no further symptoms in service. And, according to the Veteran's own testimony, he remained asymptomatic for 25 years. Furthermore, the Board acknowledges Dr. Bash's criticism of Dr. Brown's opinion for not directly addressing his opinion or that of Dr. Chudzik. The Board finds such criticism is baseless. While Dr. Brown did not cite each doctor by name, he did address the bases for their opinions and provided rationale for rejecting their conclusions. Dr. Brown even considered the possibility that a hepatic process was undocumented in service, but found that it was unlikely or at least less than 50 percent probable. In summary, the most probative evidence establishes that liver disease did not have an onset in service, is not a residual of infectious mononucleosis, and is not a result of exposure to Agent Orange during service. No residuals of infectious mononucleosis are shown. The probative evidence establishes that the etiology of the appellant's cirrhosis of the liver is unknown. The preponderance of the evidence is against the claim and there is no doubt to be resolved. Consequently, the benefit sought on appeal is denied. ORDER Service connection for infectious mononucleosis residuals is denied. Service connection for liver disease is denied. ____________________________________________ H. N. SCHWARTZ Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs