Strümpell's familial spastic paraplegia: an electrophysiological demonstration of selective central distal axonopathy.

Three patients with autosomal dominant Strümpell's familial spastic paraplegia (SFSP) were evaluated by means of somatosensory evoked potentials (SEPs) from upper and lower limb and determination of sural nerve conduction velocity. Findings of normal sural nerve conduction but reduced amplitude and poor definition of SEPs with normal latencies on peroneal nerve stimulation support a pattern of central nervous system degeneration characterized by a selective involvement of centrally directed axons within the gracile fasciculi.