The predictive value of cerebrospinal fluid tap-test in normal pressure hydrocephalus

RESUMO

Eighteen patients (mean age of 66.5 years) with normal pressure hydrocephalus (NPH) underwent a ventrículo-peritoneal shunt surgery. Prior to operation a cerebrospinal fluid tap-test (CSF-TT) was performed with measurements of gait pattern and psychometric functions (memory, visuo-motor speed and visuo-constructive skills) before and after the removal of 50 ml CSF by lumbar puncture (LP). Fifteen patients improved and 3 were unchanged after surgery. Short duration of disease, gait disturbance preceding mental deterioration, wide temporal horns and small sulci on CT-scan were associated with good outcome after shunting. There was a good correlation between the results of CSF-TT and shunt surgery (X2=4,11, phi=0.48, p<0.05), with gait test showing highest correlation (r=0.99, p=0.01). In conclusion, this version of CSF-TT proved to be an effective test to predict improvement after shunting in patients with NPH.