Clinical Efficiencies of Stabilometry and Visual Feedback Test for Differentiating the Patients with Psychogenic...

The psychogenic vertigo has been diagnosed based on subjective dizzy symptom without abnormal findings of oculomotor tests and vestibular tests. We investigated the characteristics of the postural control system in patients with psychogenic vertigo using stabilometry and Body Tracking Tests with a visual feedback test to assess the dynamic body balance. This study consisted of 14 patients with psychogenic vertigo and 92 aged-match healthy subjects. They were instructed to keep the center of pressure constantly in the target circle displayed on the screen in front of the subjects. The dynamic body balance was evaluated by the proportion of the center of pressure (COP) including in the target circle during the test. The psychogenic vertigo group showed a larger area and a smaller locus length per unit area in comparison with the healthy subject group (p<0.01). In spectral analysis with the maximum entropy method (MEM), the power of the medio-lateral and antero-posterior positional power spectrum under eyes open condition were significantly largest at around 0.125 Hz in the psychogenic vertigo group. No significant difference in the result of Body Tracking Tests with a visual feedback test was found between both groups. Our results suggest that the patients with psychogenic vertigo maintain body balance with extremely slowly and large movements for quiet stance during eyes open condition. The results of Body Tracking Tests with a visual feedback test may indicate that the spontaneous postural control itself in patients with psychogenic vertigo does not differ from that in healthy individuals. We believe that this test could be useful as one of the significant diagnostic tests for psychogenic vertigo.