Features of gait most responsive to tap test in normal pressure hydrocephalus

Clin Neurol Neurosurg. 2008 May;110(5):455-61. doi: 10.1016/j.clineuro.2008.02.003. Epub 2008 Mar 21.


Objective: To identify components of gait associated with a positive tap test (TT) in patients with idiopathic normal pressure hydrocephalus (iNPH).

Patients and methods: Thirty-three patients with iNPH underwent clinical evaluation pre- and post-TT and were classified as responders (Rs) or non-responders (NRs). Elements of gait were assessed with a formal standardized Gait Scale and compared between groups.

Results: Analysis of pre/post-TT group differences revealed an interaction for Total Gait Score and Walking Score, with improvements in responders only. Total Gait Scores improved by 29% in the Rs and 4.85% in the NRs. Rs showed significant post-TT improvements on a timed 10m walk, turning, and balance. Tandem walking, turning, truck balance and start stop hesitation showed trends toward improvement.

Conclusions: The classic features of gait often used in determining diagnosis of NPH (wide based stride, reduced foot-floor clearance, and small steps) were not helpful in identifying responders to the TT. Walking speed, steps for turning, and tendency towards falling were most likely to improve post-TT. These straightforward measures can readily be adapted into clinical practice to assist in determination of shunt candidacy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Cerebrospinal Fluid Shunts / methods
  • Chi-Square Distribution
  • Female
  • Gait Disorders, Neurologic / cerebrospinal fluid*
  • Gait Disorders, Neurologic / classification
  • Gait Disorders, Neurologic / complications
  • Gait Disorders, Neurologic / therapy
  • Gait*
  • Humans
  • Hydrocephalus, Normal Pressure / cerebrospinal fluid
  • Hydrocephalus, Normal Pressure / complications*
  • Hydrocephalus, Normal Pressure / therapy
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Spinal Puncture*
  • Task Performance and Analysis
  • Treatment Outcome