GNE myopathy - A cross-sectional study on spatio-temporal gait characteristics

GNE myopathy is a rare, predominantly distal myopathy, involving mainly the lower limbs and presenting with gait disturbances. In this cross-sectional study gait evaluation of 23 (14 men) genetically confirmed GNE myopathy patients was done using Instrumented walkway analysis (GAITRite®) along with video gait capture. We recorded the topographical pattern of muscles involvement in lower limbs and correlated Functional Ambulation Profile-FAP and Medical Research council-MRC grading of lower limb scores with duration of illness. Early foot flat, foot drop gait with wider out-toed stance and higher perturbations with increased pressure at heel and decreased arm swing were noted. Muscle topography showed predominant weakness in ankle dorsi-flexors, flexor hallucis longus, extensor hallucis longus, hip adductors and knee flexors with stark sparing of quadriceps and relative sparing of hip- abductors, extensors, flexors and ankle plantar-flexors. Gait parameters in women were significantly more affected than men (p < 0.05) for the same duration of illness. FAP score and MRC grading of lower limb scores correlated significantly with duration of illness (p < 0.05). We observed that ankle dorsiflexors were affected earliest with sparing of quadriceps muscles in these patients.