Nocturnal Hyperkinetic Spells in Dentatorubral Pallidoluysian Atrophy

Objective: To identify non-epileptic nocturnal paroxysmal spells in a rare sporadic case of DRPLA in North America. Background: Dentatorubral Pallidoluysian Atrophy (DRPLA) is a heterogeneous syndrome characterized by chorea, epilepsy, ataxia and progressive dementia. DRPLA is more common in Japan with only four families genetically confirmed in North America. Design/Methods: We review a case of DRPLA from Detroit, Michigan. Results: A 36 year-old African-American woman presents with generalized tonic-clonic seizures and mild progressive cognitive decline since age 27. At 29 years, she complained of brief nocturnal episodes of arousal, ballistic-like movements of all extremities sometimes accompanied by loud screaming. Nocturnal episodes failed to respond to levetiracetam, clonazepam, valproic acid, clobazam and escitalopram. Family history was negative for neurodegenerative disorders except for Alzheimer’s Disease in paternal grandfather. Examination revealed a score of 18 on MoCA test, dysarthria, choreoathetoid movements and ataxia in all four extremities with wide based gait. Hyperreflexia was seen diffusely. Admission to the EMU captured typical events without any EEG correlate. Semiology was non-stereotypic due to some variability. Interictal EEG showed rare generalized epileptiform discharges with no clinical correlate. MRI brain revealed generalized cerebral and cerebellar volume loss. Autoimmune, paraneoplastic and genetic workup was negative except for DRPLA showing a 64 and 10 repeat expansion of the ATN1 gene. Her night time episodes later responded to tetrabenzine, amantadine and risperidone and diagnosed as not epileptic. She was continued on levetiracetam, which controlled her bilateral tonic-clonic seizures. Conclusions: DRPLA is a rare neurodegenerative disorder that occurs sporadically in North America. Patients manifest several paroxysmal events including epileptic myoclonus, bilateral tonic-clonic seizures, and choreoathetosis. We present a new type of paroxysmal event in these patients identified as non-epileptic nocturnal dyskinesia due to failure to response to AEDs and responding to dopamine and serotonin modulation. Disclosure: Dr. Nandanwar has nothing to disclose. Dr. George has nothing to disclose. Dr. Basha has nothing to disclose.