Effectiveness of shunting in patients with normal pressure hydrocephalus predicted by temporary, controlled-resistance, continuous lumbar drainage: a pilot study.

From 1984 to 1992 15 consecutive cases of normal pressure hydrocephalus were included in this pilot study. A series of tests included CT of the brain, grading of the cognitive mental state with the mini-mental state examination; urodynamic studies, and gait evaluation. These tests were carried out on admission, and repeated on day 1, day 3, and day 5 after controlled-resistance, continuous lumbar drainage (CRCLD). During this period, eight patients showed significant improvements of cognitive mental state, urodynamic studies, or gait and were regarded as CRCLD responders; the remaining seven patients were regarded as CRCLD non-responders. The CRCLD was routinely removed on day 6 after the drainage procedure and a ventriculoperitoneal (VP) or a lumboperitoneal (LP) shunt was randomly selected for each patient. The tests were repeated one week after shunting and a year later. All the CRCLD responders continued to benefit from shunting at one week and one year after the procedure irrespective of the type of shunting they received. By comparison, none of the CRCLD non-responders showed any improvement a year after the shunting. In conclusion, CRCLD proved to be a safe and effective way to predict the effectiveness of shunting in patients with normal pressure hydrocephalus.