Citation Nr: 21064586 Decision Date: 10/20/21 Archive Date: 10/20/21 DOCKET NO. 16-40 950A DATE: October 20, 2021 ORDER Entitlement to service connection for a thyroid disability, claimed as hypothyroidism, is denied. FINDING OF FACT The competent medical evidence of record indicates that the Veteran's hypothyroidism was caused by an intercurrent disease, specifically, his treatment for hyperthyroidism. CONCLUSION OF LAW The criteria for service connection for diabetes have not been met. 38 U.S.C. §§ 1110, 1113, 1116, 1116A, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. REASONS AND BASES FOR FINDING AND CONCLUSION The Veteran served on active duty from July 1966 to April 1970. This matter comes to the Board of Veterans' Appeals (Board) on appeal from a March 2013 rating decision by the Regional Office (RO) of the Department of Veterans Affairs (VA). The Veteran presented testimony at a Board hearing in July 2019. A transcript of the hearing is associated with the Veteran's claims folder. This case was previously before the Board in November 2019 and May 2021, on which occasions the claim was remanded. Entitlement to service connection for a thyroid disability, claimed as hypothyroidism. The Veteran asserts that he is entitled to service connection for hypothyroidism based on exposure to herbicide agents while serving in Vietnam. In a previous Board decision in November 2019, the undersigned found that the Veteran served in Vietnam. To establish service connection a Veteran must generally 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." Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Service connection may also be granted for any disease 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). Veterans who, during active military, naval, or air service, served in the Republic of Vietnam from January 9, 1962, to May 7, 1975, shall be presumed to have been exposed to herbicide agents, including Agent Orange, 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(a)(6)(iii). Certain diseases enumerated under 38 C.F.R. § 3.309(e) will be presumed to have been incurred in service even though there is no evidence of that disease during the period of service at issue. These diseases must manifest to a degree of 10 percent or more at any time after service for the presumption to apply. 38 U.S.C. § 1116(a); 38 C.F.R. §§ 3.307(a)(6), 3.309(e). The National Defense Authorization Act for Fiscal Year 2021 (NDAA) added hypothyroidism among the list of diseases eligible for presumptive service connection based on herbicide agent exposure for veterans who served in the Republic of Vietnam during the Vietnam Era. The NDAA went into effect on January 1, 2021. Pub. L. No. 116-283. While hypothyroidism is presumptively related to exposure to herbicide agents, this presumption is rebuttable "[w]here there is affirmative evidence to the contrary, or evidence to establish that an intercurrent injury or disease which is a recognized cause of the disease or disabilities . . . has been suffered between the date of separation from service and the onset of any such disease or disability . . .." 38 U.S.C. § 1113. VA will consider "any evidence of a nature usually accepted as competent to indicate the time of existence or inception of disease, and medical evidence judgment will be exercised in making determinations relative to the effect of intercurrent injury or disease." 38 C.F.R. § 3.307(d). The term "affirmative evidence to the contrary" will not be taken to require a conclusive showing, but such showing as would, in sound medical reasoning and in the consideration of all evidence of record, support a conclusion that the disease was not incurred in service. Id. At the outset, the Board acknowledges that the Veteran served in Vietnam, as discussed in the Board's November 2019 decision, and therefore was presumptively exposed to herbicide agents. Additionally, the Board notes that he is currently diagnosed with hypothyroidism, a condition that is presumptively related to exposure to herbicide agents, which has manifested to a degree of 10 percent or more. (6/29/2021, C&P Exam, p. 2); 38 C.F.R. § 4.119, Diagnostic Code 7903. Generally, the above would be sufficient to warrant a grant of service connection. However, in the present case, there is affirmative evidence establishing that an intercurrent disease which manifested following the Veteran's period of active-duty service caused his hypothyroidism. Specifically, his VA medical records indicate that he was diagnosed with hyperthyroidism in the 1980s and was treated with radioactive iodine. Following this course of treatment, he developed iatrogenic hypothyroidism. (5/17/2018, CAPRI, p. 5). As explained by a VA examiner in an August 2020 medical opinion, "[p]eople who produce too much thyroid hormone (hyperthyroidism) are often treated with radioactive iodine or anti-thyroid medications. The goal of these treatments is to get thyroid function back to normal. However, sometimes correcting hyperthyroidism can end up lowering thyroid hormone production too much, resulting in permanent hypothyroidism." (8/11/2020, C&P Exam, p. 2). A subsequent VA medical opinion from June 2021 reached a similar conclusion. The examiner concluded that "the veteran's hypothyroidism is the result of medical treatment for hyperthyroidism (radioactive iodine treatment) . . .." The examiner additionally noted that "current medical literature is silent for any mechanism by which herbicide (Agent Orange) exposure may cause or aggravate hyperthyroidism." (6/29/2021, C&P Exam, p. 2). Given the aforementioned affirmative evidence that the Veteran's hypothyroidism was caused by radioactive iodine treatment for hyperthyroidism, the Board finds that the presumptive provisions of 38 C.F.R. § 3.307 have been rebutted in this case. The Board has also considered whether service connection for hypothyroidism can be granted on a direct basis. However, as previously noted, the medical evidence of record indicates that hypothyroidism was caused by his treatment for hyperthyroidism, which occurred after the Veteran's period of active-duty service. Further, there is no indication in the file that the Veteran's hyperthyroidism was related to service. (6/29/2021, C&P Exam, p. 2). In sum, while the Veteran served in Vietnam and is diagnosed with a disease presumptively related to exposure to herbicide agents, the Board finds that there is affirmative evidence that his claimed disability is related to radioactive iodine treatment for hyperthyroidism, not exposure to herbicide agents. Therefore, the presumptive service connection provisions of 38 C.F.R. § 3.307 have been rebutted. See 38 C.F.R. § 3.307(d). The Board has considered whether service connection is warranted on a direct basis; however, the aforementioned radioactive iodine treatment occurred after the Veteran's period of active-duty service. Moreover, evidence does not support a finding that hyperthyroidism was related to service. As such, service connection is not warranted. Eric S. Leboff Veterans Law Judge Board of Veterans' Appeals Attorney for the Board R. Glenn, Associate Counsel The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.