Influence of cerebrospinal fluid tapping on dynamic equilibrium in suspected hydrocephalus.

Thirty-nine patients aged 21-82 years (mean 62 years) under investigation for suspected acquired hydrocephalus were investigated by dynamic posturography before and 6-8 h after a cerebrospinal fluid tap of 20-40 ml. Dynamic posturography comprises a sensory organization (SO) part in which the platform and visual surround are either stable or referenced to the patient's sway. The eyes are closed or open. In a movement coordination (MC) part the platform makes active movements, thus introducing external disturbances in the procedure. The patients improved their balancing ability in all tests on the sway referenced platform in SO, while MC remained unaffected. It is concluded that dynamic posturography is valuable for dysequilibrium assessment in clinical evaluation of suitable candidates for ventricular shunts in acquired hydrocephalus.