Acute Stimulus-Sensitive Postanoxic Myoclonus: Description of a Case

Abstract

We describe the clinical and electroencephalographic features of a comatose patient with severe anoxic encephalopathy who experienced acute reflex myoclonus precipitated by passive eye opening/closure and painful stimulation. Acute stimulus-sensitive postanoxic myoclonus is an underdiagnosed epileptic condition. Shortly after the anoxic insult, the diagnosis should be based on EEG evaluation and various types of stimulation. These should include passive eye opening/closure and painful stimuli.

Post-hypoxic Myoclonus: Current Concepts, Neurophysiology, and Treatment

“… 45 patients with generalized myoclonus after CPR died while 5 remained in a permanent vegetative state. Fernández-Torre et al 70 EEG showed burst suppression pattern. Generalized spike and wave discharges were precipitated with touch.…”

Acute Stimulus-Sensitive Postanoxic Myoclonus

“…Thus, Niedermeyer et al 1 and Zivkovic and Brenner 2 emphasized the existence of area-specific SSPM and pointed out the trigeminal-inervated territory as a particular myoclonus-trigger zone. Later, Fernández-Torre et al 3 reported a patient with SSPM obtained by passive eye opening and closing, and painful stimulation. In our case, SSPM was obtained not only after trigeminal tactile stimuli but also following painful stimulation of the trunk and limbs.…”

“…Stimulus-sensitive postanoxic myoclonus (SSPM) is an underdiagnosed clinical phenomenon which has received little attention because it usually occurs in fatal cases. 1 –3 We describe the clinical and neurophysiologic features of another patient with acute SSPM, highlighting the importance of carrying out a protocol of sensory stimulation while recording an electroencephalogram (EEG) in comatose subjects admitted to the intensive care unit (ICU).…”

Post-anoxic myoclonus

“…3,9 Some specific stimuli, such as tactile stimuli, tracheal suctioning, nail-bed pressure, trigeminal tactile stimuli or auditory stimuli, can trigger myoclonus. 7,8,[10][11][12] chronIc Pam (lance-adams syndrome)…”