Cognitive recovery in idiopathic normal pressure hydrocephalus: a prospective study

Neurosurgery. 1994 Sep;35(3):397-404; discussion 404-5. doi: 10.1227/00006123-199409000-00006.


Idiopathic normal-pressure hydrocephalus remains difficult to treat. Controversy exists as to whether or not shunting can really improve cognitive functions and whether quantified intracranial pressure monitoring (ICP-Mo) can predict postoperative improvement rates. Several studies 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 basis of ICP-Mo when "high" waves (amplitude > 9 mm Hg) were present. Twenty-three patients underwent surgery. The preoperative and postoperative 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 correlation between high wave relative frequency and the grade of improvement (P < 0.05). At the same time, 66.6% of shunted patients showed a significant improvement in cognitive functions. Complications of shunting were successfully managed without residual deficits in this series. We recommend the use of quantitative ICP-Mo as a criterion for surgery and to predict the improvement grade.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aphasia / diagnosis
  • Aphasia / physiopathology
  • Brain Damage, Chronic / diagnosis*
  • Brain Damage, Chronic / physiopathology
  • Cerebrospinal Fluid Shunts
  • Female
  • Follow-Up Studies
  • Humans
  • Hydrocephalus, Normal Pressure / diagnosis
  • Hydrocephalus, Normal Pressure / surgery*
  • Intracranial Pressure / physiology
  • Male
  • Middle Aged
  • Monitoring, Physiologic
  • Neurologic Examination*
  • Neuropsychological Tests*
  • Postoperative Complications / diagnosis*
  • Postoperative Complications / physiopathology
  • Prospective Studies