[Progressive centripetal degeneration in polyneuropathies (author's transl)]

This is a clinicopathologic report on three patients with sensory polyneuropathies of different origin. Sensory loss involved all four limbs reaching the upper third of the thighs and the elbow level or higher, in all three patients. In addition to the limbs the central region of the anterior aspect of the trunk, from lower abdomen up to level T2, and on the top of the scalp were involved. There was minimal weakness. This pattern of sensory deficit can best be explained by a length dependent degeneration of fibers. Familial amyloidosis, Portugese type, was responsible for the neuropathy in the first patient, diabetes mellitus in the second and alcoholism in the third one. On teased nerve fiber study, single regenerating fibers were isolated on sural nerve biopsy specimens from patients 1 and 2. Segmental demyelination and/or remyelination occurred in 11 per cent of the fibres in patient 1, in 36 per cent in patient 2 and in 4 of the 19 fibres isolated in patient 3. On cross sections of nerve specimens embedded in Epon there was a striking loss of myelinated fibres which was less important and predominated on smaller fibres in patients 1 and 2. On electron microscopic examination loss of unmyelinated fibres was conspicuous in all three patients. On single fiber studies as well as on sections of embedded specimens, myelinated fibres occasionally showed demyelination in contact to amyloid deposits. The present study demonstrates that in this pattern of neuropathy degeneration of myelinated fibers begins in the distal part of longest axons and may be associated with axonal sprouting in more proximal parts of degenerating axons. As the neuropathy progresses axons of shorter and shorter length become involved.