Cognitive recovery in idiopathic normal pressure hydrocephalus after shunt.

OBJECTIVE

Evaluate long-term changes in cognition after ventriculoperitoneal shunt insertion in patients with idiopathic normal pressure hydrocephalus.

BACKGROUND

Although studies have indicated that treatment of normal pressure hydrocephalus with ventriculoperitoneal shunt improves gait, effects of treatment on cognition have been inconsistent. Several studies have reported no significant improvement on neuropsychological tests in patients with idiopathic normal pressure hydrocephalus. Selection of candidates for shunt surgery using a trial of controlled spinal fluid drainage via lumbar catheter may result in more consistent improvement in cognition.

DESIGN/

METHODS

This was a prospective, longitudinal study of performance on neuropsychological tests before and 6 to 12 months after insertion of a ventriculoperitoneal shunt in 10 patients with idiopathic normal pressure hydrocephalus who showed improvement in at least 1 clinical symptom with temporary lumbar drainage. Nonparametric tests were used to evaluate change.

RESULTS

Significant group improvements at follow-up were demonstrated on tests of verbal memory as well as in 1 test of psychomotor speed. Eight of 10 patients showed improvement by more than 1 standard deviation on at least 1 memory test. Six of 10 patients improved significantly on more than 50% of the tests administered.

CONCLUSIONS

Patients with idiopathic normal pressure hydrocephalus who show clinical improvement (in any symptom) after lumbar drainage are likely to show significant long-term improvement in memory after ventriculoperitoneal shunt.