Postictal laughter following absence status epilepticus.

Acute pathologic neurologic laughter has been described as an ictal phenomenon in epilepsy, as a result of electrical brain stimulation to the cortex and to deep brain structures, in brain tumors, and in stroke. We report what is, to our knowledge, the first report of a case of postictal pathologic laughter. Previously diagnosed with medically refractory complex partial seizures, our patient was admitted to the hospital with phenytoin toxicity. During video-EEG monitoring she experienced multiple brief absence seizures as well as a prolonged episode of absence status epilepticus. Immediately following cessation of the seizure she began to laugh. Her laughter was mirthful and infectious. This lasted several minutes and was followed immediately by several minutes of crying and then a return to normal. We propose that diffuse cortical inhibition led to release of subcortical structures involved in emotional expression. Possible neural substrates of laughter are discussed.