SSRI induced hypnic jerks: A case series.

A hypnic jerk is an abrupt, involuntary, nonrepetitive contraction of muscles of the body that occurs during the onset of sleep in stage 1 of nonrapid eye movement sleep. Various physiological and stressful stimuli can precipitate hypnic jerks with no further neurological sequelae. Although selective serotonin reuptake inhibitor (SSRI) medications are well known to disturb the normal sleep cycle and cause rapid eye movement sleep behavioral disorders, there were only a few case reports of them causing hypnic jerks and those were reported due to Escitalopram only. Here is a case series of four cases of hypnic jerks found to be associated with the use of various SSRIs, Escitalopram, Sertraline, and Fluoxetine. Clonazepam was found to be very effective in reducing the hypnic jerks associated with SSRIs. In all the cases, the sleep-induced Electroencephalogram was normal.