[Temporary lumbar external drainage in normal pressure hydrocephalus].

In a prospective study twenty-two patients diagnosed as suffering from idiopathic normal pressure hydrocephalus, were investigated using temporary external lumbar drainage. Five patients had to be excluded from the study because of complications of external lumbar or definite ventricular shunting. External drainage correctly predicted the outcome of shunting in all of the remaining seventeen patients. This technique appears to be a safe and valuable tool for predicting the outcome of definitive shunting procedures.