The clinical usefulness of posturography is unknown, despite its costing more than $500 per test in some areas of the United States, including Boston. We cross-sectionally and prospectively studied blinded vestibule-ocular and vestibulospinal tests from 29 stable patients with chronic vestibular hypofunction; 22 patients were affected bilaterally (BVH), and 7 were affected unilaterally (UVH). Vestibuloocular function was assessed by electronystagmographic caloric stimulation and sinusoidal vertical axis rotation gains at 0.05 Hz. Vestibulospinal function was assessed by moving-platform and visual-surround posturography sensory organization tests (SOTs), paced and free gait in a gait laboratory, and clinical tests of timed gait and standing. Posturography SOT moving-platform tests 4 through 6, designed to assess vestibular function, correlated significantly (r less than or equal to 0.72, P greater than or equal to 0.01) with vestibule-ocular tests in 5 of 6 comparisons among BVH patients. Posturography SOT results, however, correlated poorly with other vestibulospinal measures: correlations were statistically significant for only 7 of 18 comparisons with clinical balance and gait function (r less than or equal to 0.69, P greater than or equal to 0.01) and with 2 of 12 comparisons for gait laboratory dynamic stability measures (r less than or equal to 0.55, P greater than or equal to 0.01) among the BVH patients. When both the platform and visual surround moved (SOT 6), however, correlations were statistically significant with static standing clinical measures (r = 0.51 to 0.69, P < 0.01) and with whole-body maximum moment arm during paced gait (r = 0.55, P < 0.01). Posturography scores for the UVH patients did not significantly correlate with any vestibule-ocular or other vestibulospinal measures. These data indicate that among patients with BVH posturography SOT scores relate at best modestly with accepted measures of vestibule-ocular function, less well with clinical measures of balance control, and poorly with dynamic gait-performance measures. We conclude that posturography SOT does not assess vestibulospinal function.
