Rinsho Shinkeigaku (Clinical Neurology)

Case Report

Morvan syndrome associated with unresectable thymoma responsive to chemotherapy: a case report

Takayuki Nonaka, M.D.1j, Ikumi Ebisu, M.D.1j, Ikkei Ohashi, M.D.1j, Hirohiko Shizukawa, M.D.1j and Shun Shimohama, M.D., Ph.D.2j

1) Department of Neurology, Sapporo-Kosei General Hospital
2) Department of Neurology, Sapporo Medical University School of Medicine

A 51-year-old Japanese man presenting with a several-month history of parasomnia, orthostatic hypotension and generalized myokymia was admitted to our hospital. He had a past medical history of unresectable recurrent thymoma, but chemotherapy for thymoma was discontinued according to the patientfs decision four years before this hospitalization, and the thymoma had enlarged. He exhibited symptoms of the peripheral nervous system (myokymia), central nervous system (parasomnia, short-term memory impairment), and autonomic nervous system (orthostatic hypotension), and his serum was positive for voltage-gated potassium channel (VGKC)-complex antibodies. Based on the above findings, Morvan syndrome was diagnosed. Resumption of chemotherapy for thymoma resulted in shrinkage of the thymoma accompanied by remission of Morvan syndrome. Subsequently, discontinuation of chemotherapy led to aggravation of thymoma with recurrence of Morvan syndrome. This clinical course suggests a strong correlation between the disease activity of thymoma and Morvan syndrome. In the present case of Morvan syndrome associated with unresectable thymoma, chemotherapy contributed to the remission of Morvan syndrome. Our patient suggests a possibility that chemotherapy for thymoma is a useful treatment for Morvan syndrome.
Full Text of this Article in Japanese PDF (1656K)

(CLINICA NEUROL, 62: 615|620, 2022)
key words: Morvan syndrome, thymoma, chemotherapy, voltage-gated potassium channel (VGKC)-complex antibodies, parasomnia

(Received: 29-Nov-21)