Progressive Encephalomyelitis With Rigidity and Myoclonus

Segment 1: Fifteen months old. First relapse. We observe episodes of hyperekplexia, generalized hyperextension with limb rigidity, and myoclonus, induced by auditory stimuli with rapid startle response. Her eye movements are uncoordinated on horizontal and vertical planes. She has mild perioral cyanosis and peripheral oxygen desaturation.