[Delayed postanoxic encephalopathy].

We report the case of a 9-year-old boy with delayed postanoxic encephalopathy. The patient improved after a period of coma and adult respiratory distress syndrome caused by benzodiazepine intoxication. Initial improvement appeared to be complete, but 9 days after discharge from the pediatric intensive care unit, extrapyramidal rigidity of the left arm became manifest. This event was followed by progressive neurologic impairment with involuntary, non-repetitive, but occasionally stereotyped movements, affecting distal, proximal and axial musculature in various combinations. On physical examination, passive movement of the left arm showed a plastic, lead-pipe rigidity with a ratchet-like cogwheel quality. Magnetic resonance imaging (MRI) was performed. Axial T 2 -weighted images of the brain showed characteristic signs of an ischemic area in the basal ganglia which were more evident in the right region, a finding consistent with anoxic-ischemic encephalopathy. Delayed postanoxic encephalopathy is a relatively uncommon and unexplained phenomenon which becomes manifest after an initial hypoxic-ischemic event that causes stupor or coma. The pathogenesis is unknown. Exceptionally, this syndrome can affect the basal ganglia more than the cerebral cortex and white matter. Initial improvement is followed after a variable period of time by relapse, progressing for weeks to months until the patient is left with permanent sequelae.