1250 Agrypnia Excitata in a Patient with Paraneoplastic Autoimmune Encephalitis

Abstract

Abstract Introduction Agrypnia Excitata (AE) is a syndrome characterized by loss of sleep with permanent motor and autonomic hyper activation. This case describes this peculiar syndrome in a patient with paraneoplastic autoimmune encephalitis. Report of Case DG is a 35 yr old male with a history of anti-Ma2 limbic encephalitis secondary to cystic teratoma of the left testis diagnosed 6 months prior to presenting in Sleep Clinic. His parents described significant sleep disturbances including short sleep and wake periods throughout the day and night with no apparent pattern, acting out dreams, motor activity during sleep including pulling at his clothes or using his hands to manipulate invisible objects. Additionally they described low-grade fevers, and severe hyperphagia. Polysomnogram showed absence of slow-wave sleep and what appeared to be an admixture of stage 1 non-rapid eye movement (NREM) with rapid-eye movement (REM) sleep. Multiple sleep-latency testing (MSLT) demonstrated a mean sleep latency of 5.2 minutes and four sleep-onset REM periods (SOREMPs). Magnetic resonance imaging of the brain revealed persistent inflammation of the mesial temporal lobes and hippocampal region. Cerebral spinal fluid testing showed persistent anti-Ma2 antibodies. Based on this clinical presentation we made a diagnosis of Agrypnia Excitata. Conclusion Agrypnia Excitata is a syndrome characterized by loss of the normal sleep-wake rhythm. Sleep consists of the disappearance of spindle-delta activities, and persistent stage 1 NREM sleep mixed with recurrent episodes of REM sleep. The second hallmark of AE is persistent motor and autonomic hyperactivity observed during wake and sleep. AE has been described in three distinct clinical syndromes: Morvan Syndrome (autoimmune encephalitis), Fatal Familial Insomnia, and Delirium tremens. The pathogenesis of AE consists of intra-limbic disconnection releasing the hypothalamus and brainstem reticular formation from cortico-limbic inhibitory control. In autoimmune encephalitis, antibodies that act on voltage-gated potassium channels within the limbic system have been implicated in the pathophysiology.