Walking ability and cognitive function change in normal pressure hydrocephalus patients after cerebrospinal fluid tap test

Cerebrospinal fluid tap test is a helpful supplementary test for normal pressure hydrocephalus diagnosis, but the evaluation time and methods always puzzle clinicians. 33 patients with probable normal pressure hydrocephalus in PUMC hospital from 2013 to 2014 were included. All patients were evaluated using MMSE, MOCA, ADL, NPH scale, underwent 1.5T head MRI scan and were transferred to neurosurgical department to have ventriculo-peritoneal shunt if they were willing to. A lumbar tap with removal of 30 ml of CSF was performed in all patients. Evaluations included the 10m walking time and steps, TMT-A, number code and STROOP test. Those tests were performed one day before and 8, 24, 72 hour after CSF tap test. Compare the walking test and neuropsychological test results before with those after the CSF tap test. Correlate the NPH featured MRI characters with CSF TT responses including Evan's index, callosum corpus angle, mismatch between narrowed high-convexity and medial subarachnoid spaces and enlarged Sylvian fissure associated with ventriculomegaly. The 10m walking time after CSF tap test were significantly improved (p<0.0125). On every evaluation time point there were no statistical differences. The neuropsychological tests changings were not significant except the TMT scale on 72hr after, the number code scale on 24hr and STROOP C scale on 72hr. The CSF TT responders tended to have the feature of mismatch between narrowed high-convexity and medial subarachnoid spaces and enlarged Sylvian fissure (p<0.05). The Evan's index and callosum corpus were not statistically correlated with the response of CSF TT.