[Guillain-Barré syndrome: morphological lesions and their relations with clinical manifestations]

Acute demyelinization of the peripheral nervous system is a characteristic feature of Guillain-Barré syndrome. Lesions of the spinal roots predominate with more or less diffuse multifocal peripheral demyelinization. Inflammatory lesions of the distal peripheral nervous system are less common. Segmentary demyelinization of nerve fibers accompanying inflammatory lesions show characteristic penetration of macrophages within a normal appearing myelin sheath. The myelin on the segments concerned is rapidly destroyed by phagocytosis and removed with the macrophages. Once the debris has been removed, the axons are remyelinized after proliferation of the Schwann cells. In monophasic cases, the entire processes occurs over a 2-3 week period allowing remyelinization and rapid functional recovery. In prolonged cases, flare-ups of demyelinization, non remyelinization or damage to the axons can retard recovery. The mechanism and impact of axon damage which accompanies demyelinization at various degrees and which may predominate in certain cases, is discussed here.