Ducic I, Plastic Surgery, Georgetown University Hospital, 3800 Reservoir Road, NW, Washington, DC, USA and Dellon AL, Plastic Surgery, Institute for Peripheral Nerve Surgery, Johns Hopkins University, 3333 North Calvert Street, Suite 370, Baltimore, MD, USA.
Falls and fall-related fractures are a source of enormous morbidity with high resultant health care and disability costs. Falls are the most common cause of injury and hospital admissions for trauma and account for 87% of fractures in individuals older then 65. Neuropathy is a known cause of decreased sensibility in the feet. To date, no report has investigated the relationship between loss of balance with the degree of sensibility in the foot in a population with neuropathy. 10 control and 35 patients with sensory abnormalities and balance problems were evaluated. MatScan Measurement System was used to measure their ability to stand still, maintaining their balance with their eyes open and then with their eyes shut. The degree to which the person moves while attempting to stand still was defined as "sway". Sensibility of the foot was measured with the Pressure-Specified Sensory DeviceTM. The one and two-point static touch thresholds are measured for the pulp of the big toe, medial heel, and the dorsum of the foot. Loss of two or one point sensation was recorded as sensibility score and compared to controls. There were 55 % females in control and 64 % in neuropathy patients, while average age was 50 and 62 respectively. Neuropathy was due to diabetes in 64.5 %, hypothyroidism in 19.3 percent, their combination in 13 %, and of unknown etiology in the remaining 19 % of patients. Controls had significantly lower mean sway than neuropathy patients (22.9±9 % vs. 189.5±180 %, p=0.006). Likewise, sensibility score for normal and neuropathy patients was also significantly different (31.4±9 % vs. 232.8±59 %, p<0.0001). When compared with the control's, 99 percent upper limit of confidence, sensibility in the neuropathy group at the hallux pulp was abnormal at a level consistent with axonal loss in 52 % and was completely absent in the remaining 48 percent. Similarly, at the heel, sensibility was normal in 6.5 %, abnormal at a level consistent with axonal loss in 71 % and absent in the remaining 22.5 %. The correlation coefficient between sway and sensibility score was 0.36. The results of this investigation for the first time documents the intuitive relationship between increasing loss of foot sensibility and increasing loss of balance. These measurements can now be used prospectively to evaluate whether restoration of sensation to patients with neuropathy, through peripheral nerve decompression, can improve balance, and reduce falls/fractures in this patient population.