GUILLAIN-BARRE-SYNDROME IN NORTHERN CHINA - THE SPECTRUM OF NEUROPATHOLOGICAL CHANGES IN CLINICALLY DEFINED CASES

The pathology of the Guillain-Barre syndrome remains controversial, an d autopsied cases available for study by contemporary techniques are u ncommon. Large numbers of cases clinically diagnosed as Guillain-Barre syndrome occur in northern China. In this study we examined the neuro pathological changes in 12 autopsied cases from Hebei Province, China. Eleven died early in the course of their disease. In all cases tissue was specially handled and fixed for electron microscopy and for immun ocytochemistry. Three of these 12 cases had typical acute inflammatory demyelinating polyneuropathy (AIDP) with lymphocytic infiltration and macrophage-mediated demyelination, reproducing the pathological pictu re most often reported in Guillain-Barre syndrome in North America, Eu rope, and Australia. Six cases had predominantly axonal involvement, c haracterized by Wallerian-like degeneration of new fibres, with only m inimal demyelination and with minimal inflammation in five. Three case s, even though paralysed at the time of death, had only very mild chan ges in the spinal roots and sciatic nerves. Within the group of six pr edominantly axonal cases, there were important differences both in the severity of the abnormalities and in the classes of fibres involved. Three cases had extensive Wallerian-like degeneration of sensory as we ll as motor fibres [acute motor-sensory axonal neuropathy (AMSAN)], wh ile in the other three cases the fibre degeneration affected the motor nerve fibres almost exclusively. These latter cases establish a struc tural basis for the clinical and electrophysiological picture termed t he acute motor axonal neuropathy (AMAN) pattern. In both the AMAN and the AMSAN patterns, a prominent feature was the presence of macrophage s within the periaxonal space, surrounding or displacing the axon, and surrounded by an intact myelin sheath. These studies show that the ea rly pathological changes in cases clinically diagnosed as the Guillain -Barre syndrome are diverse and not restricted to the well-known patte rn of AIDP and that the predominant pathological patterns may differ i n different parts of the world. The differences in pathological findin gs gs between acute inflammatory demyelinating polyneuropathy and the axonal patterns are likely to reflect differences in the pathogenetic mechanisms. The periaxonal macrophages in the axonal patterns suggest that an important epitope may be localized to the axolemma or periaxon al space. The mild cases indicate that severe paralysis can occur earl y in Guillain-Barre syndrome without prominent structural changes alon g the nerve, suggesting that physiological block or nerve terminal cha nges may be implicated.