A second episode occurred after 11 months, during sleep, and consisted of impairment of consciousness, hypotonia, deviation of the eyes to the right, hypersalivation, and right-sided clonic convulsions.

A tetanic muscular contraction, the "electric spasm, is followed after a latency of seconds by unconsciousness, a high voltage paroxysmal spike and sharp-wave discharge, and a clonic convulsion.

The time taken before the onset of clonic convulsions, the duration of clonic convulsions, and the percentage of seizure and mortality protection were recorded [ 26 ] .

Clinical signs of PEM are variable depending on the area of the cerebral cortex affected and may include head pressing, dullness, opisthotonos, central blindness, anorexia, muscle tremors, teeth grinding, trismus, salivation, drooling, convulsions, nystagmus, clonic convulsions, and recumbency.