Objectives: Our aim was to evaluate corpus callosum functioning in a group of patients with normal pressure hydrocephalus (NPH) before and after shunting.
Methods: Left ear-extinction under a dichotic listening task was evaluated in twenty-three patients with NPH, 30 patients with Alzheimer's disease and 30 aged controls.
Results: Patients with NPH had higher levels of left ear extinction than the control and Alzheimer's groups. Sixty-one percent of NPH patients exhibited left ear suppression, compared with 13% of Alzheimer's patients and 17% of controls. Following surgery, NPH patients showed a significant change in the degree of asymmetry in the dichotic listening task.
Conclusions: Hydrocephalus was associated with left-ear extinction,which diminished after surgery. Our results may indicate reversible functional damage in the corpus callosum.