Nocturnal Hypermotor Syndrome in Obstructive Sleep Apnea Mistaken for Seizures and Parasomnias (P05.008)

Abstract

Objective: We report a case series of nocturnal hypermotor syndrome in obstructive sleep apnea (OSA) mistaken for seizures and parasomnias. Background A known cause of rhythmic movements in sleep, OSA-related arousals may also provoke complex movements and behaviors in sleep. Design/Methods: Case report. Results: Seven patients were referred for unusual movements and behavior in sleep with initial suspicion for parasomnias or seizures. A 41-year-old man had rhythmic, side-to-side leg rolling at 2-3 Hz, left greater than right. A 41-year-old woman had flailing movements of the limbs. A 63-year-old woman had various complex movements (ankle, knee and hip flexion followed by extension and repetitive hip abduction). A 54-year-old man had body rolling movements with repetitive left wrist flexion-extension followed by rhythmic leg rolling. A 51-year-old man and 71-year-old woman had complex periodic leg movements. In all cases, polysomnography (PSG) with additional muscle and electroencephalographic (EEG) channels showed these movements being triggered by respiratory events in sleep. A 49 year old woman had a history of violent behavior in sleep, with no recollection on awakening. Her PSG showed bizarre complex movements (rhythmic abduction-adduction of legs, flexion and extension of hips and knees, raising her leg up in the air at 90 degrees, fiddling with wires and clothing, sitting up confused, bending her right arm behind her head and tapping her abdomen, as well as sitting up in bed, drinking a soda and speaking with the technician while asleep) induced by sleep disordered breathing. In all cases, these movements responded to upper airway pressurization. Conclusions: Hypermotor syndrome in OSA is often misdiagnosed as parasomnias or seizures, but responds to treatment of sleep disordered breathing with upper airway pressurization. PSGs with appropriately selected additional EEG and EMG channels aid in diagnosis and prevent expensive and unnecessary additional testing and treatment. Disclosure: Dr. Salim has nothing to disclose. Dr. Bhat has nothing to disclose. Dr. Lysenko has nothing to disclose. Dr. Patel has nothing to disclose. Dr. Chokroverty has received personal compensation for activities with Elsevier and Cephalon. Dr. Chokroverty has received personal compensation in an editorial capacity for Sleep Medicine Journal.