Remarkable recovery of a steroid-responsive recurrent polyneuropathy.

Idiopathic recurrent polyneuropathy is one of several distinct syndromes involving the peripheral nervous system which share similar microscopic alterations of the interesting Schwann cell-myelin sheath of the axon collectively referred to as hyper-trophic neuropathies (Austin, 1956; Byers and Taft, 1957; Thomas and Lascelles, 1967). In all six patients with hypertrophic neuropathy studied by Thomas and Lascelles (1967), extensive segmental demye-lination was present. Moreover, this paranodal loss of myelin was seen in certain areas in the absence of any other pathological alteration, suggesting to these investigators that segmental demyelination was the initial morphological alteration in these diseases. Presumably, if this process of demyelination and subsequent remyelination continues, other charac-teristic alterations ensue, including shortening of the internodal lengths, as seen on longitudinal sections, and concentric cellular proliferation around individ-ual axons with variable accumulation of 'connective tissue ' in the endoneurial spaces as seen on cross-section. These reactive changes to chronic injury have been shown to be manifestations of Schwann