Signs, symptoms and course of normal pressure hydrocephalus in comparison with cerebral atrophy.

Between May 1982 and January 1997 we investigated 200 patients for normal pressure hydrocephalus (NPH) by performing an intrathecal infusion test. 168 patients (84%) presented with the clinical syndrome of gait ataxia, dementia and urinary incontinence, the so called Adams triad. In 107 patients (54%) the diagnosis of a NPH could be confirmed. Of these, 102 patients (95%) underwent a shunt operation. In a follow-up (7 month and 3 years later) we interviewed the patients or their relatives about the progression of the disease. At those time intervals we could evaluate the improvement after shunt operation or infusion test. In our experience gait ataxia is the guiding sign of NPH. Regarding dementia we could not find a significant difference compared to cerebral atrophy. Urinary incontinence can be characterized as a symptom of late stage NPH. The complete Adams triad should not be overestimated in differential diagnostic considerations. Subdivision of NPH into an early stage and a late stage allows one to conclude prognostic evaluations about the course of the disease. Patients with an early stage NPH reported at the follow-up an improvement of their symptoms after shunt operation in 65 percent and those with a late stage NPH in 50 percent. The computer aided infusion test allows a safe differentiation between patients with NPH and those with cerebral atrophy.