Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 74

Abstract

It is well known that painful neuropathy of the small fiber type is frequent in Fabry disease, however it has been rarely investigated in childhood. We report an 11‐year‐old boy without known familial history of neuromuscular diseases, who complained of painful symptoms in the lower extremities by age 9. Initially pain was present only in association with fever, but during the last year it was triggered also by mild variations in the environmental temperature, so that the boy, to prevent pain, was forced to stay barefooted for most the time during spring and summer, and to wear at least two or three pairs of socks during winter. Physical and neurological examination was negative, except for several small red spots in the testes. Neurophysiological study was negative, but EMG showed motor unit potentials with possible myopathic pattern. Muscle biopsy was unremarkable, apart from endothelial cells containing electron dense lipid inclusions of regular lamellar structure, which were seen also in skin biopsy within fibroblasts, pericytes and endothelial cells. Intraepidermal nerve fiber density was within normal limits (5.5/mm at distal leg and 8.3/mm at proximal thigh), but prominent axonal swellings (possible predegenerative changes) were frequently seen. Diagnosis of Fabry disease was confirmed by deficiency of alfa‐galactosidase. Symptomatic treatment with gabapentin was started, in addition to enzyme replacement therapy. Symptoms of small fiber neuropathy in Fabry disease may be present in early disease as an onset manifestation, and the occurrence of small fiber neuropathy during childhood strongly suggests a diagnosis of Fabry disease. Painful symptoms may occur before a significant intraepidermal nerve fiber loss is seen, and are probably correlated to predegenerative changes in the small sensory fibers.