Guillain-Barré Syndrome

Mild cases of AIDP may never come to medical attention, but the typical presentation in those that seek medical assistance is one of acute ascending paralysis, which reaches its peak within 4 weeks. These motor findings are the most characteristic, although in some cases, paresthesias or pain may accompany the weakness. In severe cases, respiratory failure can occur, sometimes requiring intubation. Autonomic dysfunction may coexist, manifesting as hemodynamic instability with labile blood pressures, heart rates, and even cardiac arrhythmias, and patients may need hemodynamic support. Intensive care unit–level care is commonly required.

Physical examination generally reveals symmetric weakness, although some asymmetry can occur. The weakness can worsen rapidly in these patients and requires close monitoring. Significant sensory loss is atypical. Reduced or absent reflexes are common. Cranial nerve dysfunction is less common, although facial nerve palsy (sometimes asymmetric) is seen in up to 30% of patients, and extraocular muscles are affected in about 5%. Tongue and palate involvement is rare.

Variants of AIDP may present a diagnostic challenge; these include acute motor axonal neuropathy (AMAN), an axonal variant of AIDP with a worse long-term prognosis, an acute autonomic neuropathy, and Miller-Fisher syndrome (characterized by ataxia, areflexia, and ophthalmoplegia) in addition to the more typical AIDP presentation.

Nearly all patients with AIDP require hospitalization, even in mild cases, because progression of weakness is expected. The standard of care treatment is intravenous immunoglobulin or plasmapheresis. Supportive measures are necessary. Monitoring and management of respiratory and autonomic dysfunction has significantly reduced mortality. Other complications that should be prevented or treated include deep vein thrombosis, pulmonary emboli, pressure sores, and hyponatremia. Early involvement with physical therapy is important. AIDP is self-limiting in most patients. The maximum deficit is usually seen in 2 to 4 weeks, and improvement follows, with the course determined by the degree of axonal damage that accompanied demyelination. If axonal damage is severe, maximum recovery may take more than a year, and there may be significant residual weakness. Most patients eventually recover from AIDP, but the course is variable, and approximately 20% are left with some permanent disability.

DIAGNOSIS OF AIDP

Electrodiagnostic studies can be extremely useful for evaluating patients with possible AIDP, but much of what are considered to be the most characteristic electrophysiologic features are often not present on studies done in the very early stages of the disease process. Among the earliest changes seen is loss of or prolongation of F-wave latencies or H reflexes. Over time, other features of demyelination, such as prolonged distal latencies, slowed conduction (usually measured along intermediate segments of nerve), and temporal dispersion, can be seen. Needle examination is usually not as revealing but may reflect neurogenic changes from axonal injury, which is secondary to the inciting inflammatory demyelinating process. These changes occur late in the disease process. The findings on electrodiagnostic studies mirror the degree of underlying pathologic changes in the four stages of the AIDP, as shown in the illustration.

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