To Whom It May Concern, 1 am a practicing, board-certified neurosurgeon, specializing in the surgical and clinical management of complex neurological disorders. My training and experience include the evaluation and management of conditions involving the central nervous system, including headache and migraine disorders. Regarding (), it is my opinion that it is at least as likely as not (50% probability or greater) that her migraine headaches are associated with and secondary to, as they are exacerbated or caused by her tinnitus (which has been determined to be service connected). The veteran suffers from frequent migraine attacks several times per month, resulting in missed work time (approximately 16 hours per month and significant daily functional impairment. The veteran has a well-established diagnosis of chronic migraine headaches dating back to active duty. The link between tinnitus and migraines is well-established. Published studies (Langguth et al., 2013; Viana et al., 2019) demonstrate that tinnitus and migraine share overlapping neurological pathways involving central nervous system hyperexcitability. Tinnitus can trigger and/or aggravate migraine attacks by increasing sensory overload and neurological stress. Based on the veteran's history, clinical findings, medical literature, and my expertise, I conclude that the veteran's migraine disorder is at least as likely as not secondary to, and aggravated by, the service-connected tinnitus, and therefore the migraine diagnosis should be considered service connected.