Inexcitability of nerves in a fulminant case of Guillain-Barre syndrome

A 45-year-old woman presented with a recent sensorimotor deficiency in all 4 limbs, and the next day she was totally paralyzed. A slight motor improve ment began on day 27. The cerebrospinal fluid had normal cellularity, but t he protein varied from 90 mg/dL on the first day to 800 mg/dL on day 15, an d then 290 mg/dL on day 33. Electrophysiologic studies performed on days 15 and 23 revealed a universal peripheral nerve inexcitability. A superficial peroneal nerve biopsy was performed on day 23. Nine fascicles were examine d on semi-thin sections and myelinated fiber damage varied greatly from one fascicle to another. At ultrastructural examination, certain axons were se verely damaged, but the others were quite well preserved and were naked or wrapped in a myelin sheath presenting a multivesicular degeneration. A few fibers had a better-preserved myelin sheath that was sometimes dissociated by elongated processes from an invading histiocyte. Six cases of fulminant Guillain-Barre syndrome with inexcitability of nerves and ultrastructural e xamination of nerve fragments have been reported. Electrophysiologic study is often ambiguous and cannot determine the precise origin of such an axona l degeneration. Therefore, ultrastructural analysis of a nerve biopsy is ma ndatory in this setting.