Guillain–Barré syndromes and chronic inflammatory demyelinating polyradiculoneuropathy

Guillain–Barré syndromes (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are inflammatory disorders of the peripheral nervous system that share some common pathological features and probably share pathogenic mechanisms. GBS is an acute inflammatory neuropathy usually leading to flaccid paralysis in a matter of days (by definition less than four weeks). There are several variants with different courses and prognoses. The diagnosis of GBS does not usually require pathologic confirmation but neuropathology has contributed to understanding its pathogenesis although several questions remain unanswered. Plasma exchange, intravenous immunoglobulin (IVIg), and general supportive measures (including mechanical ventilation) have greatly improved the overall prognosis of GBS, but there is still an urgent need for more effective therapies. CIDP, which can be regarded as the chronic counterpart of GBS is a potentially disabling chronic inflammatory neuropathy, whose pathologic hallmark is inflammatory-mediated demyelination with secondary axon loss. The clinical presentation is quite variable and nerve conduction studies are an important part in the diagnostic workup. In typical cases, treatment with corticosteroids or IVIg (or alternatively plasma exchange) may be started as soon as the diagnosis is confirmed, and the course of the disease is usually altered by these treatment options. Nonetheless, atypical cases where the diagnostic criteria are not fulfilled are common. Atypical cases may require pathologic confirmation in order to make the diagnosis or to rule out alternative options. Although not all pathologic features of CIDP are specific, a careful examination of a nerve biopsy sample may greatly help confirming its diagnosis. The pathogenesis of CIDP remains largely obscure mainly because a definite target antigen has not been identified. Based on clues inferred from nerve biopsy findings, new treatment options should allow the prognosis to be improved.