Caspr2 autoantibody-associated Morvan syndrome predating thymoma relapse by 30 months.

Morvan's syndrome (MoS) is a rare autoimmune disorder characterized by central nervous system involvement, autonomic dysfunction and peripheral nerve hyperexcitability. MoS is believed to be caused by autoantibodies targeting contactin-associated protein 2 (Caspr2), a subunit of the neuronal voltage-gated potassium channel (VGKC) complex, usually in association with thymoma, less commonly with other malignancies. This case highlights an exceptional case of severe sleep disturbances and behavioural changes due to MoS, in a patient who would present with and be treated successfully for a second relapse of thymoma 30 months later. Originally he suffered from ocular myasthenia, another autoimmune disorder, which led to diagnosis of his original thymoma and first relapse.