None: A patient was transferred for management of "medication-refractory seizures" after failure of levetiracetam and valproate dual therapy. She had a life-long history of two types of events: periods in which she would rapidly and uncontrollably lapse into unconsciousness, and spells in which she would "pass out" but maintain consciousness, the latter happening with increasing frequency in association with laughing, as of late. She also reported hypnogogic/hypnopompic hallucinations, sleep paralysis, and disrupted nocturnal sleep. A clinical diagnosis of narcolepsy was made. The prevailing pathophysiological concept of narcolepsy details "partial intrusions of REM" sleep into wakefulness. Healthy REM sleep includes generalized atonia, but with preservation of eye movements, respiratory function, and sphincter tone. Cataplexy recapitulates this pattern, and is often induced by extreme emotions, laughter in this case. Despite generalized and severe weakness and areflexia during this patient's cataplectic events, she was able to volitionally move her eyes, which is consistent with the physiology of REM sleep. The diagnosis of cataplexy is often missed, due to clinicians being unfamiliar with the findings and the lack of ability to induce sufficient emotional responses to trigger an episode. This example of cataplexy is also quite characteristic of the "cataplectic facies." The ability to observe the infrequently observed phenomenon of cataplexy serves as a reminder that consciousness is preserved, as are extra-ocular muscle movements.
View details for DOI 10.5664/jcsm.8148
View details for PubMedID 31957646