Hydrocephalus as a cause of disturbances of gait in the elderly.

To investigate the possible role of symptomatic normal-pressure hydrocephalus (NPH) in unexplained walking difficulties of the elderly, we used CT to measure lateral ventricular size. We compared data in 50 patients over the age of 60 with a disturbance of gait and 80 control subjects of similar age who walked well and were mentally sound. Forty-six of the 50 gait patients (92%) had a ventricular span of more than 12 mm, whereas only 5 of the 80 controls (6.3%) had ventricles of that size. There was a narrow zone of overlap. Seventeen of the gait patients later improved after surgical shunting or test withdrawal of lumbar CSF. These findings demonstrate that hydrocephalus is an important cause of disturbances of walking in the elderly. The validity of the study, the clinical picture in NPH, and the nature of NPH are discussed.