Outcome of shunt operation on urinary incontinence in normal pressure hydrocephalus predicted by lumbar puncture.

Bladder function in four patients with normal pressure hydrocephalus, one with dementia of Alzheimer type and five patients with multi-infarct dementia was studied by history and urodynamic tests (cystometry and Bor's ice water test). The bladder hyperactivity could be temporarily improved by a lumbar puncture and removal of 50 ml CSF and later abolished by a shunt operation in patients with normal pressure hydrocephalus while no changes occurred in the other patients. Urodynamic testing in connection with a lumbar puncture may be a reliable way to predict the outcome of a shunt operation in cases of normal pressure hydrocephalus.