Dynamic stabilometric findings in equilibrium disorders of the elderly.

Equilibrium disorders are frequent symptoms of aging, both on account of the so-called "multisensorial decay" and age-related diseases. Aim of the study was to evaluate the functional integrity of static-dynamic postural control related subsystems (visual, somatosensorial, vestibular), the fundamental postural strategies effected and adaptation to destabilizing inputs, in elderly subjects with otoneurological disorders. From January to November 2003, 40 elderly patients (19 male, 21 female, mean age +/- SD: 69.5 +/- 4.3 years; range: 65-83), with balance disorders, consisting in dizziness or vertigo, have been observed. Otoneurologic and internal case history was collected in all patients, all of whom were submitted to otoscopy, otoneurologic examination, pure-tone audiometry, as well as a specific examination called Equi test. The sensorial analysis, as often occurs in elderly subjects without unbalance, revealed marked impairment of the somatosensorial (85%), compared to vestibular (60%) and visual (40%), subsystems. Longer latencies of motor responses to forward platform translations than to backward translations were observed, even if the symmetry of movements was more evident in the former. Postural adaptation was more frequently impaired during raising of the support (70%) than during lowering. Therefore, in elderly people, somatosensorial impairment, combined with flexor muscle dysfunction, exists. Indeed, extensor responses, although slower than flexor responses, are more correctly performed.