SENSORY NEUROPATHY IN INFANTILE ONSET SPINOCEREBELLAR ATAXIA (IOSCA)

Infantile onset spinocerebellar ataxia with sensory neuropathy is a ne w, inherited multisystem disorder discovered in 19 Finnish patients. i n order to define the neuropathy of the disease, we measured sensory n erve action potentials and nerve conduction velocities in 18 patients, and recorded somatosensory evoked potentials (SEP) in 10 patients and performed a sural nerve biopsy in 13 patients. The fixed and teased n erve fascicles were examined by light and electron microscopy, and the whole transverse section of a nerve fascicle was photographed and enl arged for morphometric measurements. Our investigation revealed an ear ly onset, rapidly progressive axonal neuropathy: the sensory action po tentials were decreased after the age of 2 and a severe loss of mainly large myelinated fibers was found. (C) 1994 John Wiley and Sons, Inc.