Improved postural control after computerized optokinetic therapy based on stochastic visual stimulation in patients with vestibular dysfunction.

Balance is accomplished by the congruent integration of visual, vestibular and somatosensory input and the execution of adequate control movements. With increasing age, nonlinear dynamics of central control systems become more regular. In unilateral vestibular dysfunction, sensory input to central systems is similarly less complex, because of one sided reduction of information influx. This study aimed to increase postural stability in patients with vestibular asymmetry and resulting disequilibrium by implementing a computerized visual training method relying on the principles of stochastic resonance. 24 subjects (average age 64a, 31-78a, 15 women, 9 men), with minimum 3 months of persisting disequilibrium due to vestibular dysfunction, were either treated with computerized optokinetic therapy (COKT), or solely observed. Treated patients were requested to read texts, stochastically moving in a previously defined matrix, during 10 sessions over three weeks. The Sensory Organization Test (SOT) was used for comparative posturographic measurements. COKT patients showed significant improvement in conditions 4, 6 and composite score. A significant post-therapeutic difference was seen between therapy and control groups in conditions 1, 6 and composite score. The results show a clinical benefit and we conclude COKT to be an effective rehabilitation method in patients with chronic disequilibrium.