REM sleep behavior disorder in Brunner syndrome.

ABSTRACT

Brunner syndrome is a recessive X-linked disorder characterized by intellectual disability and impulsive aggressiveness associated with Monoamine Oxidase-A (MAOA) deficiency leading to increased monoaminergic activity. We report the presence of REM sleep behavior disorder (RBD) in a 46-year-old patient with Brunner syndrome due to a c.1438A>G/iVS14-2 A>G mutation of the MAOA gene. He suffered from mild intellectual disability and psychotic disturbances. He presented a 15-year history of nightmares (chase, attacks and fights), sleep-related vocalizations and motor behaviors characterized by talking, screaming, crying, gesturing, punching, and kicking. Video-polysomnography showed RBD characterized by excessive tonic and phasic muscle activity in the mentalis and limb muscles with dream enacting behaviors during REM sleep. Clonazepam achieved a significant reduction of RBD symptomatology. We conclude that RBD can be a manifestation of Brunner syndrome probably due to an increased monoaminergic neurotransmission occurring in this rare genetic disorder.