A Case Report of an Atypical Presentation of Morvan Syndrome.

Morvan syndrome, also known as Morvan's fibrillary chorea, is a rare paraneoplastic neurological syndrome presenting with central nervous system (CNS) symptoms, peripheral nerve hyperexcitability, and autonomic nervous system (ANS) manifestations. The etiology and severity of the disease are not well understood. An adult female presented with a sudden onset of chest pain, unilateral extremity weakness, blepharospasms, and muscle spasms, with positive voltage-gated potassium channel (VGKC) antibody and positive neuronal antibody (amphiphysin) in serum. Morvan syndrome can be diagnosed in patients with myokymia, positive VGKC antibody, and neuropsychiatric symptoms with a high clinical index of suspicion. This atypical presentation of Morvan syndrome in a female identifies a novel association of amphiphysin positivity in this rare disease.