Parkinsonian syndrome after cardiac arrest: radiological and neurochemical changes.

Following a cardiac arrest, a 21-year-old man developed a Parkinson syndrome. This was due to, as shown by brain computerized tomography (CT) and magnetic resonance imaging (MRI), symmetrical infarctions of the basal ganglia, especially the globi pallidi. The levels of homovanillic acid (HVA) in the CSF were lower than normal, pointing to a possible alteration of the central dopaminergic activity. An alteration of the opioid system may also be supposed because of the extremely high levels of methionine-enkephalin (Met-Enk).