Morvan Syndrome Manifesting as Autoimmune Paraneoplastic Encephalitis Associated with Thymoma and Antivoltage Gated Potassium Channel (Leucine Rich, Glioma Inactivated 1) Antibody Detected using F 18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Morvan's syndrome (MoS) is a rare, complex neurological disorder characterized by neuromyotonia, neuropsychiatric features, dysautonomia, and neuropathic pain. The majority of MoS cases have a paraneoplastic etiology, most commonly thymoma, usually occurring before the diagnosis of the underlying tumor and showing improvement following surgery. We present a case of 60-year-old patient presenting with suspicious of MoS and autoimmune encephalitis (AE), F-18 fluorodeoxyglucose positron emission tomography/computed tomography as single imaging modality detected and confirmed both AE and thymoma.