O R I G I N A L A R T I C L E Body Sway in Diabetic Neuropathy LUIGI UCCIOLI, MD PIER GIORGIO GIACOMINI, MD GLOVANNA MONTICONE, MD ANTONIO MAGRINI, MD LAURA DUROLA, MD ERNESTO BRUNO, MD LEO PARISI, MD STEFANO DI GIROLAMO, MD GUIDO MENZINGER, MD OBJECTIVE — To evaluate the influence of peripheral neuropathy on body sway assessed by posturography. RESEARCH DESIGN AND METHODS— The age-matched study subjects included 10 insulin-dependent diabetes mellitus (IDDM) patients with peripheral neuropathy (DN), 23 IDDM patients without peripheral neuropathy (D) according to the San Antonio Consensus Conference guidelines, and 21 control subjects (C). All subjects with symptoms and/or clinical signs of postural instability were excluded from the study. RESULTS — The trace surface was significantly larger in the DN than in the C and D groups (P < 0.05), and the trace length was longer in the DN than in the C and D groups (P < 0.01). Mean velocity was faster in the DN than in the other two groups (P < 0.001). A direct relationship was found between the parameters of posturography and some parameters of the nerve conduction velocity. CONCLUSIONS — Diabetic patients with peripheral neuropathy demonstrate a relative deficit in their ability to maintain posture. Posturography allows an early disclosure of the failure of postural control. P osture results from complex interac- tions between vestibular, ocular, and proprioceptive sensory inputs and motor outputs (1,2). Postural sway is an expression of the postural muscle ac- tivity during standing and induces a con- tinuous to-and-fro movement of the pro- jection of the point of gravity. Whenever a disturbance of one sensory input and/or of the motor output is present, an abnor- mality of the postural sway is expected. It is evident that posture makes From the Department of Endocrinology and Internal Medicine and the Department of Otolar- yngology (P.G.G., A.M., E.B., S.D.G.), University of Rome "Tor Vergata"; and the Department of Neurology (L.P.), University of Rome "La Sapienza," Rome, Italy. Address correspondence and reprint requests to Luigi Uccioli, MD, Cattedra di Endocrinolo- gia, Dipartimento di Medicina Interna, Universita di Roma "Tor Vergata," c/o Complesso Inte- grato Columbus, via della Pineta Sacchetti, 506, 00168 Rome, Italy. Received for publication 19 May 1994 and accepted in revised form 20 October 1994. IDDM, insulin-dependent diabetes mellitus; MVEL, mean velocity of body sway; NCV, nerve conduction velocity; RI, Romberg Index; VPT, vibratory perception threshold. considerable demands on the peripheral nervous system, and peripheral neuropa- thy secondary to diabetes, disrupting both the afferent and the efferent path- ways, is believed to cause postural insta- bility. Although patients with peripheral neuropathy seldom, and only in an ad- vanced stage, report symptoms of pos- tural instability, insulin-dependent dia- betes mellitus (IDDM) patients with peripheral neuropathy report, with in- creased frequency, episodes of injuries and falls while standing and walking (3). It is surprising that very few re- ports have addressed this topic (4-6). This is probably due to the uncertainty of the symptoms that are commonly consid- ered to be part of peripheral neuropathy rather than to comprise an autonomous clinical entity. Static posturography, which records sway patterns and parameters, is an objective method to evaluate func- tional performance in diseases that affect balance (7). The purpose of this study was to evaluate body sway in IDDM patients with peripheral neuropathy and to corre- late the static posturography results with those of the clinical examination and neu- rography. RESEARCH DESIGN AND M E T H O D S — Fifty-four subjects were enrolled after a thorough interview to elim- inate any potentially interfering neurologi- cal condition (alcohol addiction, thyroid disease, lumbar root disease, etc.). They had a corrected visual acuity of 10/10 and were free of any labyrinthine signs or symptoms. All subjects who displayed symptoms or showed clinical evidence of postural instability were excluded from the study. The subjects were distributed into three groups: C, 21 control subjects; D, 23 IDDM patients without peripheral neuropathy; and DN, 10 IDDM patients with peripheral neuropathy. Diabetic pa- tients were included in the group with neuropathy (DN) according to the San Antonio Consensus Conference guide- DIABETES CARE, VOLUME 18, NUMBER 3 , MARCH 1995 339 Downloaded from http://diabetesjournals.org/care/article-pdf/18/3/339/526561/18-3-339.pdf by guest on 17 June 2022