Parkinsonism after Shunting for Hydrocephalus Secondary to Aqueductal Stenosis with Chiari Malformation

摘要

Parkinsonism has been well-documented in patients with communicating hydrocephalus, but it is an uncommon complication of shunting for obstructive hydrocephalus secondary to aqueductal stenosis. Although a number of hypotheses regarding anatomical and pathophysiological clues to this are proposed, its exact mechanism remains unclear. The author presents a unique case of parkinsonism after shunting for hydrocephalus due to aqueductal stenosis with Chiari malformation. Suboccipital craniectomy and duraplasty followed by ventriculoperitoneal shunting was performed, parkinsonian symptoms developed after the shunt revision, and short-term levodopa therapy resulted in complete recovery. Case Report This 25-year-old man had a history of progressive headache during eight years before admission. He was admitted with increment in his headaches, drowsiness and vomiting with visual troubles; in the emergency room he was entubated because of development of loss of consciousness and bradycardia. Computerized tomography (CT) demonstrated obstructive hydrocephalus with a marked enlargement of lateral and 3rd ventricles (Figure 1). An external ventricular drainage (EVD) catheter was inserted to decrease the intracranial pressure. Magnetic resonance imaging (MRI) showed hydrocephalus associated with aqueductal stenosis, in addition to a hydromyelia extending from C2 to C5 level and tonsillar herniation confirming diagnosis of Chiari malformation type 1 (CM-1) (Figure 2). Following the removal of the EVD catheter, a suboccipital craniectomy and C1 laminectomy was performed. Intraoperative ultrasonography (US) revealed “pistoning” movement of the tonsils during systole-diastole pulsations. The dura mater was incised, the herniated tonsils were separated, and coagulated with achieving a free cerebrospinal fluid. Following duraplasty, valsalva maneuver was performed to ensure that foramen magnum obstruction by further tonsillar descent did not occur.