Abstracts

Rationale: There have been reports of a possible association between epilepsy and REM sleep behavior disorder (RBD), but to our knowledge, no previous descriptions delineating a close temporal association in the onset of these disorders in the absence of an underlying unifying symptomatic disorder. We here describe two cases of older men presenting with both temporal lobe epilepsy (TLE) and RBD that had each evolved in close temporal association. Methods: Report of two cases of newly diagnosed TLE occurring in close temporal association with RBD onset from a tertiary sleep disorders and epilepsy center, with accompanying neurophysiologic data. Results: Case 1 is a 64-year-old Caucasian man with a 2-year history of nocturnal spells of wandering, unresponsiveness, and convulsions, and daytime spells of loss of awareness, staring, oral automatisms, occasional drooling, bilateral arm stiffening and finger rubbing, with post-ictal confusion. During the same timeframe, for 1.5 years prior to presentation, he had developed nocturnal vocalizations, verbalizations, and dream enactment behaviors with partial dream recall, without administration of anti-depressants. One of his habitual focal dyscognitive seizures was witnessed in the office with unresponsiveness, staring, oral automatisms, repeated swallowing, and right hand automatisms, with postictal amnesia for a test phrase and paraphasic errors with reading. Case 2 is a 68-year-old Asian man with a single episode of loss of awareness while driving occurring one year ago where he found himself on the opposite side of the road, not knowing how he got there. Within months prior to presentation, he had also developed a history of dream enactment behaviors with vivid nightmares, without administration of anti-depressants. Video-PSG with added arm EMG leads and 16-channel EEG was completed in both cases. In case 1, left temporal spikes and sharp waves were noted without seizures. In case 2, bitemporal slowing and independent right and left temporal sharp waves were noted without seizures. In both cases, increased tonic and phasic chin, arm, and leg EMG tone were noted during REM sleep without dream enactment behaviors. Both patients also had normal brain MRI with seizure protocol and paraneoplastic antibody panels (including potassium channel complex and GAD-65 auto-antibodies). Conclusions: In both subjects, the onset of TLE and RBD occurred within a 6-12 month period, suggesting an association between temporal lobe epilepsy and RBD. To our knowledge, the close temporal association of EEG abnormalities, seizures, and RBD has not been previously reported in the absence of an underlying unifying symptomatic disorder such as a paraneoplastic or inflammatory etiology. A neurodegenerative or ischemic cerebrovascular process may be the culprit, particularly in this age group, or alternatively, TLE may invoke limbic network alterations that predispose to occurrence of nightmares and downstream altered REM sleep atonia mechanisms in the hypothalamus, dorsal pons, or medulla.