Acute and chronic neuropathies: new aspects of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, an overview and an update.

During the last 15 years new information about clinical, electrophysiological, immunological and histopathological features of acute and chronic inflammatory neuropathies have emerged. Thus, the Guillain-Barré syndrome (GBS) is no longer considered a simple entity. Subtypes of the disorder besides the typical predominant motor manifestation, are recognized, i.e. a cranial nerve variant with ophthalmoplegia, ataxia and areflexia, an immune-mediated primary motor axonal neuropathy (AMAN), and a motor-sensory syndrome (AMSAN). Also, the clinical pattern of GBS is related to preceding viral or bacterial infections. Two types of acute motor paralysis have been described, one with slow and incomplete recovery, another with recovery times identical with acute inflammatory demyelinating polyneuropathy (AIDP). Histologically, the first is characterized by Wallerian degeneration of motor roots and peripheral motor nerve fibres. In the latter anti-GM antibodies bind to the nodes of Ranvier producing a failure of impulse transmission. Motor-point biopsies have shown denervated neuromuscular junctions and a reduced number of intramuscular nerve fibres. Molecular mimicry has been postulated as a possible mechanism triggering GBS. Thus, in the cranial variant antibodies to ganglioside GQ1b recognizes similar epitopes on Campylobacter jejuni strains and similar observations apply to anti-GM1 antibodies. Chronic inflammatory demyelinating polyneuropathy (CIDP) also has several different clinical presentations such as a pure motor syndrome, a sensory ataxic variant, a mononeuritis multiplex pattern, relapsing GBS, and a paraparetic subtype. Each of the acute and the subtypes have different, more or less distinct, electrophysiologic and pathological findings. Instructive patient stories are presented together with there electrophysiologic and biopsy findings.