Balance Stability Characteristics of Individuals with Idiopathic Normal Pressure Hydrocephalus.

OBJECTIVE

To observe postural control problems in patients with idiopathic normal pressure hydrocephalus (iNPH).

DESIGN

Cross-sectional study.

SETTING

General hospital (patients with iNPH) and the local community (individuals without iNPH).

PARTICIPANTS

A total of (N=44) elderly individuals (23 patients with iNPH and 21 individuals without iNPH).

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Balance score, including a comprehensive balance score, visual score, somatosensory score, and vestibular score.

RESULTS

Patients with iNPH exhibited significantly lower balance scores than those without iNPH across multiple Sensory Organization Test (SOT) conditions. The composite balance score was significantly lower in patients with iNPH, with a large effect size (Cohen's d=1.824; P<.001). This overall deficit was further reflected across individual SOT conditions, where large effect sizes were observed for SOT 1 (Cohen's d=1.217; P<.001) and SOT 4-6 (r=0.512-0.667; all P<.05), whereas SOT 2 showed a moderate effect size (r=0.412; P<.05). Sensory system analysis further revealed that both vision and vestibular scores were significantly impaired in patients with iNPH, with large effect sizes for both modalities (r=0.656 and r=0.502, respectively; both P<.05).

CONCLUSIONS

Patients with iNPH exhibited dynamic balance disorders, with a large effect size for overall balance impairment. Sensory system analysis further revealed large effect sizes for both visual and vestibular dysfunction, suggesting that impairments in these sensory modalities may constitute a primary sensory mechanism underlying postural instability in this population.