Lower-body parkinsonism: reconsidering the threshold for external lumbar drainage.

BACKGROUND: An 80-year-old man with a 60 pack-year smoking habit, hypertension, and hypercholesterolemia presented to a movement disorders clinic with a 30-month history of step-wise progression of gait, balance, and memory impairment. He had experienced multiple falls and two hospitalizations for sudden-onset freezing of gait. INVESTIGATIONS: Neurological examination, brain MRI, neuropsychological evaluation, gait analysis, continuous external lumbar drainage of cerebrospinal fluid, and post-mortem neuropathological studies. DIAGNOSIS: Vascular parkinsonism was diagnosed on the basis of the patient's history and imaging findings; however, post-mortem neuropathology was consistent with a diagnosis of normal pressure hydrocephalus and did not support that of vascular parkinsonism. TREATMENT: Ventriculoperitoneal shunt placement superseded tighter control of vascular risk factors, as judged by the patient's response to continuous lumbar drainage.