Abstract

During the last 10 years or so new information about clinical, electrophysical, 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 and ataxia, an immune-mediated primary motor axonal neuropathy (AMAN), and a pure sensory syndrome. Also, the clinical pattern of GBS is related to the preceding viral or bacterial infections. Similarly, chronic inflammatory demyelinating polyneuropathy (CIDP) has several different clinical presentations such as a pure motor syndrome, a sensory ataxic variant, a mononeuritis multiplex pattern, relapsing acute GBS, and a paraparetic subtype. Each of the acute and chronic subtypes have different more or less distinct electrophysiologic and pathologic findings. Two types of acute motor paralysis have been described, one with slow and incomplete recovery, another with recovery times identical with AIDP. Histologically, the first is characterized by Wallerian degeneration of motor roots and peripheral motor nerve fibres. In the latter anti-GN1 antibodies bind to the nodes of Ranvier producing failure of impulse transmission. Motor-point biopsy has showed 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 nerve variant antibodies to ganglioside GQ1b recognizes similar epitopes on Carnpylobacter jejuni strains and similar observations apply to anti-GM1 antibodies. Samples of different electrophysiological patterns as an aid to predict demyelination will be presented and discussed in relation to previous proposed criteria.