Assessment of Postural Stability Using Foam Posturography at the Chronic Stage After Acute Unilateral Peripheral Vestibular Dysfunction

Abstract

To investigate the utility of foam posturography for assessing equilibrium at the chronic stage after acute unilateral peripheral vestibulopathy. Thirty-four consecutive patients (16 patients at the chronic stage) with acute unilateral peripheral vestibulopathy and absent caloric responses unilaterally were recruited, along with 66 healthy control subjects. Two-legged stance tasks were performed in 4 conditions: with eyes open or closed, with or without using foam rubber. We adopted 6 parameters: the movement velocity of the center of pressure, the envelopment area traced by the movement of the center of pressure with eyes closed/foam rubber, Romberg's ratios of velocity and area with foam rubber, and the foam ratios (the ratio of a parameter measured with and without foam rubber) of velocity and area with eyes closed. All 6 parameters were significantly higher in the patients in the acute/subacute stage (<3 mo) than in the control subjects (p < 0.0001). Five parameters, excluding the foam ratio of the area with eyes closed, were still significantly higher in the patients at the chronic stage (>3 mo) than in the control subjects (p < 0.01). Foam posturography is useful for assessing equilibrium even at the chronic stage after acute unilateral peripheral vestibulopathy.