Muscle pathology in the early stage of Guillain-Barré syndrome

Although many studies have been performed on nervous tissue pathology in Guillain-Barré syndrome (GBS), much less is known about pathological changes in skeletal muscle in this disorder. We have studied muscle biopsies from 5 patients with GBS, 5 patients with amyotrophic lateral sclerosis (control A), and 5 patients with polyarteritis nodosa (control B). We also examined muscle obtained after death from 7 patients without neurologic or muscular diseases (control C). By light microscopy, all specimens from patients with GBS exhibited necrosis and/or phagocytosis, none of which was observed in the other three controls. Neither small angulated fibers nor small group atrophy was found in patients with GBS and in control C, by contrast with controls A and B. Ultrastructurally, filamentous bodies, subsarcolemmal aggregates of mitochondria, accumulation of glycogen particles, and concentric laminated bodies were present much more frequently in patients with GBS than in all controls. Only GBS patients showed cytoplasmic bodies. These observation suggests that there is muscle involvement in the early stage of GBS and that these muscle changes may have an intimate and important relationship to the pathogenesis of GBS.