Patients with somatoform phobic postural vertigo: the more difficult the balance task, the better the balance performance.

The objective was to test, whether the increased body sway activity, shown in patients with phobic postural vertigo (PPV) in a previous posturographic study, impairs postural balance during demanding balance tasks. In 17 patients with PPV and 15 normal subjects body sway was analyzed for two standing positions on a foam rubber-padded posturographic platform with the eyes open or closed: (a) normal upright stance, (b) tandem stance. During normal upright stance patients showed an increase in body sway activity between 0.1 and 19 Hz and in sway path values for lateral and fore/aft directions. During the most difficult balance task, i.e. tandem stance with the eyes closed, body sway activity and sway path values did not differ between patients and controls. Objective balance skills were not impaired in patients with PPV during balance tasks at the limits of postural control.