Long-term outcome in patients with suspected normal pressure hydrocephalus.

OBJECTIVE: To evaluate the outcome of patients with suspected normal pressure hydrocephalus at 6 months and 5 years after shunt surgery.
METHODS: Seventy-five patients (mean age, 72.5 6 9 yr), with normal pressure hydrocephalus symptoms were included. Fifty-four patients with positive lumbar infusion and/or cerebrospinal fluid tap tests received a cerebrospinal fluid shunt, whereas 21 patients with negative test results did not undergo operation. Walk, reaction time, memory, and identical forms tests were used as baseline (before surgery) tests and were repeated at short- (6.1 6 4.6 mo) and long-term (5.5 6 1.4 yr) follow-up evaluations. Activities of daily life functions were assessed using the Barthel index.
RESULTS: At the 6-month follow-up examination, 83% of the operated patients improved in gait, 65% improved in reaction time, 46% improved in memory, and 31% improved in identical forms tests; 96% found themselves subjectively improved. Because of unrelated mortality (37%) and declining general health from comorbidity, only 27 patients were available for the 5-year follow-up evaluation. Twenty-three of these patients had been treated with a shunt and had a remaining improvement in close to 40% in gait and reaction time, whereas fewer than 10% had an improvement in cognitive tests. Fifty-six percent reported subjective improvement compared with preoperative findings. More patients (64%) improved if younger than 75 years; for patients older than 75 years, only 11% of the patients improved. The Barthel index was higher (P < 0.05) in improved patients.
CONCLUSION: Patients with normal pressure hydrocephalus benefit from shunt surgery for at least 5 years. High mortality rate, comorbidity, and old age hamper good long-term outcome and emphasize the importance of patient selection.