Pure akinesia manifested neuroleptic malignant syndrome: a clinical variant of progressive supranuclear palsy.

An autopsy case of pure akinesia (PA) is reported. The patient manifested L-dopa-unresponsive akinesia without accompanying rigidity, tremor, eye movement disorder or dementia from the age of 58 years. Brain magnetic resonance T2-weighted imaging at the age of 63 showed high intensity areas in the subthalamic regions, but brain atrophy was not observed. She received amantadine-HCl and L-threo-3,4-dihydroxyphenylserine (L-DOPS) for 5 years. At the age of 66, she died of the severe illness accompanied by consciousness disturbances, hyperthermia, muscle rigidity, abnormal blood pressure and elevated serum enzymes which were derived from the muscle. We considered her condition to be neuroleptic malignant syndrome (NMS). Pathologically the brain revealed degeneration in the subthalamic nucleus, globus pallidus and substantia nigra. Neurofibrillary tangles were detected in the temporal cortex, hippocampus, amygdaloid body and spinal cord, as well as in the basal ganglia, thalamus and brain stem. These findings were consistent with that of progressive supranuclear palsy (PSP); the change in the ventral pons was insignificant, suggesting that PA may have minimum involvement in the ventral pons. The skeletal muscle showed scattered necrosis that was compatible with NMS. As far as we know, this is the first report of NMS accompanied with PA.