Gait in normal pressure hydrocephalus: characteristics and effects of the CSF tap test

ABSTRACT Normal pressure hydrocephalus (NPH), described by Hakim and Adams in 1965, is characterized by gait apraxia, urinary incontinence, and dementia. It is associated with normal cerebrospinal fluid (CSF) pressure and ventricular dilation that cannot be attributed to cerebral atrophy. Objectives: To evaluate gait characteristics in patients with idiopathic NPH and investigate the effect of the CSF tap test (CSF-TT) on gait. Methods: Twenty-five patients diagnosed with probable idiopathic NPH were submitted to the CSF-TT. The procedure aimed to achieve changes in gait parameters. Results: Fifteen gait parameters were assessed before and after the CSF-TT. Five showed a statistically significant improvement (p < 0.05): walking speed (p < 0.001), cadence (p < 0.001), step length (p < 0.001), en bloc turning (p = 0.001), and step height (p = 0.004). Conclusion: This study demonstrated that gait speed was the most responsive parameter to the CSF-TT, followed by cadence, step length, en bloc turning, and step height.