Morvan chorea and agrypnia excitata: When video-polysomnographic recording guides the diagnosis

Abstract 

Introduction

Morvan chorea is an antibody-mediated limbic encephalopathy characterized by severe insomnia, mental confusion, hallucinations, enacted dreams, hyperhidrosis, and neuromyotonia.

Case description

In a 78years old man presenting with progressive insomnia apathy and depression, a video-polysomnogram documented enacted dreams mimicking daily life activity (oneiric stupor). This finding led us to perform a search for serum antibodies to voltage-gated K+ channels, which was positive. A diagnosis of Morvan chorea was done. The patient underwent plasma exchange with complete resolution of the clinical picture.

Conclusions

Oneiric stupor may represent a useful precocious diagnostic marker in Morvan chorea.

Keywords: Morvan chorea, Limbic encephalopathy, Oneiric stupor, Agrypnia excitata, REM sleep behaviour disorder, Video-polysomnography