Postural control before and after cerebrospinal fluid shunt surgery in idiopathic normal pressure hydrocephalus.

OBJECTIVES: This study aimed to confirm whether cerebrospinal fluid (CSF) shunting for idiopathic normal-pressure hydrocephalus (iNPH) improves postural instability, and to investigate the relationship between postural control and gait ability.

PATIENTS AND METHODS: Twenty-three iNPH patients and 18 age-matched healthy controls (HC) were examined using the timed up and go (TUG) test and a force platform for calculating the center of pressure (COP) trajectory during voluntary multidirectional leaning and quiescent standing. We determined the patients' TUG values and COP trajectories before and after shunt surgery.

RESULTS: Postural sway was greater in iNPH patients before shunt surgery and the TUG value was lower in iNPH patients before shunt surgery than in HC. Voluntary COP movements were significantly improved in iNPH patients at 1 week post-surgery, but no significant changes in quiescent standing were found between pre- and post-surgery. Significant correlations were found between the TUG value and voluntary COP movements in iNPH patients before and after surgery, but no significant correlations were observed between the TUG value and quiescent standing.

CONCLUSION: Our results indicate that CSF shunting in iNPH patients may improve voluntary postural control and reduce the risk of falling. Impaired voluntary COP control in iNPH patients may reflect the underlying pathophysiological mechanisms of balance disturbance in iNPH.