Idiopathic normal pressure hydrocephalus in the aged

Abstract

Continuous lumbar cerebrospinal fluid pressure measurement was made in 19 cases of aged patients suspected of idiopathic normal pressure hydrocephalus. Based on the pressure study, they were divided into high pressure group (H group) and normal pressure group (N group). H group was composed of 11 cases and N group of 8 cases. Baseline pressures in H group and N group were 16.3 ± 3.0 mmHg, 9.6 ± 1.7 mmHg, respectively and the difference was statistically significant. Pulse pressure was high in H group and frequency of pressure waves was also significantly high in H group. There were no significant differences in clinical symptoms and CT findings between the two groups, except for clinical improvement after cerebrospinal fluid removal, which was noted in all of 6 cases examined in H group. No difference between them was noted on CT cisternography and cerebral blood flow measurement. Shunt surgery was carried out in the cases of H group and it was effective in 8 of 11 cases (72.7%). Thus, continuous lumbar cerebrospinal fluid measurement was useful for selection of idiopathic normal pressure hydrocephalus in the aged.