Objective: To assess the diagnostic usefulness of posturography in 2 well-defined patient groups with impaired balance.
Patients: Ten control subjects, 10 patients with bilateral vestibular loss, and 10 patients with cerebellar atrophy.
Outcome measures: Amplitude, velocity, and frequency of sway in the anteroposterior and medial-lateral directions on a static platform, on foam, and on a moving platform.
Results: Both patient groups consistently had increased sway compared with controls, particularly when standing on foam or on a moving platform with eyes closed. Sway amplitude and velocity were increased about the same amount. The Romberg ratio (sway with eyes closed/sway with eyes open) did not reliably differentiate patients from controls or the 2 patient groups from each other. Some patients with cerebellar atrophy exhibited a characteristic body tremor at about 3 Hz in the anteroposterior direction.
Conclusions: Although sway amplitude and velocity were consistently increased in patients with bilateral vestibular loss and patients with cerebellar atrophy, none of the posturography measurements reliably distinguished the 2 patient groups. The finding of increased frequency of sway in the anteroposterior direction in patients with cerebellar atrophy was of limited value since the tremor was visible at the bedside.