Evaluation of abnormalities of orthostatic postural control in systemic sclerosis

Systemic sclerosis (SSc) is a multi-systemic disease of unknown etiology characterized by damage to the small arteries, arterioles and capillaries. The documented occurrence of various neuropathies in SSs patients led us to hypothesize that there is a potential for postural control impairments in such disease. This study was aimed at evaluating the orthostatic postural control of SSc patients who do not manifest balance or hearing symptoms.

Postural stability was assessed in 36 female SSc patients by means of a static computerized posturography technique. Their immunological and microvascular condition were evaluated by means of blood tests and microcapillaroscopy of the digital vessels. Posturography and microcapillaroscopy were performed before and after treating the patients with Iloprost. In order to compare results, posturography was also carried out on a control group composed of 10 healthy women of similar age. Both groups were studied in two different sensory conditions, i.e. with eyes opened and with eyes closed.

Posturography results showed relevant differences in body sway between patients and control subjects. Fourier spectral analysis of body sway showed that, independently from visual control, SSc patients exhibit a higher level of low/middle frequency oscillations (both on the lateral and the anteroposterior axis). No relationship was established between disease stage and postural performance.

This study seems to indicate a subtle neurophysiological dysfunction in the orthostatic postural control of female SSc patients. Further tests on the somatosensory neurological function of SSc patients may help support the above mentioned findings.