COGNITIVE RECOVERY IN IDIOPATHIC NORMAL-PRESSURE HYDROCEPHALUS - A PROSPECTIVE-STUDY

IDIOPATHIC NORMAL-PRESSURE HYDROCEPHALUS remains difficult to treat. C ontroversy exists as to whether or not shunting can really improve cog nitive functions and whether quantified intracranial pressure monitori ng (ICP-Mo) can predict postoperative improvement rates. Several studi es have drawn attention to the lack of a prospective study concerning the surgical outcome of this condition. We have performed such a study on idiopathic normal-pressure hydrocephalus patients shunted on the b asis of ICP-Mo when ''high'' waves (amplitude >9 mm Hg) were present. Twenty-three patients underwent surgery. The preoperative and postoper ative clinical states were assessed by a quantitative procedure blind to the ICP-Mo results. A clear postshunting improvement was seen in 96 % of the patients at 1 year with a statistically significant correlati on between high wave relative frequency and the grade of improvement ( P < 0.05). At the same time, 66.6% of shunted patients showed a signif icant improvement in cognitive functions. Complications of shunting we re successfully managed without residual deficits in this series. We r ecommend the use of quantitative ICP-Mo as a criterion for surgery and to predict the improvement grade.