The use of dynamic posturography to detect neurosensorial disorder in IDDMwithout clinical neuropathy

The main aim was to evaluate the relative importance of sensory interaction s for postural stability in 45 patients with insulin-dependent diabetes mel litus (IDDM) with and without peripheral neuropathy. All subjects had norma l electronystagmography. Dynamic posturography provides functional, selecti ve testing of three sensory modalities in maintenance of balance, i.e., ves tibular, visual, and somatosensory. The Sensory Organization Test (SOT) inc ludes six test conditions during which the subject tries to maintain an upr ight stance with as little sway as possible. The subject stands on a movabl e platform facing a square visual surrounding, which can be rotated indepen dently. The test is performed first with the eyes open, then with the eyes closed. The second component of posturography testing consists of the Motor Control Test (MCT) concerning motor responses routinely used in balance ma intenance. Compared to control subjects, IDDM patients with peripheral neur opathy but not patients without neuropathy showed lower scores for test con ditions SOT 1 (analysis of variance, ANOVA F = 8.3; Scheffe test: p = 0.000 7), SOT 2 (F = 6.6; p = 0.004), SOT 3 (F = 3.4; p = 0.04), and SOT 6 (F = 3 .4; p = 0.04). The muscle response latencies in MCT were prolonged for smal l forward perturbations (F = 4.6; p = 0.02) in neuropathic patients (148.3 +/- 14.2 ms) with respect to control subjects, but not in non-neuropathic p atients with respect to control subjects (135.2 +/- 13.3 ms). Sural (r = 0. 2; p = 0.002) and peroneal (r = 0.12; p = 0.02) nerve conduction velocities showed significant correlations with muscle response latencies of MCT for small forward perturbations. Our results suggest a subclinical dysequilibri um in IDDM patients with peripheral neuropathy. The results of dynamic post urography may reflect the impairment of the somatosensory system, rather th an a specific lesion of vestibular and/or visual modalities. (C) 1999 Elsev ier Science Inc.