stops. Recovery may be delayed for months. Most patients recover functionally.

Autonomic dysfunction. Tachycardia and other arrhythmias, postural hypotension, hypertension, and vasomotor symptoms, when present, support the diagnosis. These findings may fluctuate. Care must be exercised to exclude other bases for these symptoms, such as pulmonary embolism.

Absence of fever at the onset of neuritic symptoms.

Variant clinical features (not ranked in order of importance)

Fever at the time of onset of neuritic symptoms.

Severe sensory loss with pain.

Progression beyond 4 weeks. Occasionally, a patient's disease will continue to progress for many weeks longer than 4 weeks or the patient will have a minor relapse.

Cessation of progression without recovery or with major permanent residual deficit remaining.

Sphincter function. Usually, the sphincter is not affected, but transient bladder paralysis may occur during the evolution of symptoms.

Central nervous system involvement. Ordinarily, Guillain-Barré syndrome is thought of as a disease of the peripheral nervous system. Evidence of central nervous system involvement is controversial. In occasional patients, such findings as severe ataxia interpretable as cerebellar in origin, dysarthria, extensor plantar responses, and ill-defined sensory levels are demonstrable, and these need not exclude the diagnosis if other features are typical.

Cerebrospinal fluid (CSF) features strongly supportive of the diagnosis

1. CSF protein. After the first week of symptoms, CSF protein levels are elevated or have been shown to rise on serial lumbar punctures.

2. CSF cells. Counts of 10 or fewer mononuclear leukocytes/mm³ of CSF.

1. Variant CSF features supportive of diagnosis

2. No increase in the level of CSF protein in the period from 1 to 10 weeks after the onset of symptoms (rare).

3. Counts of 11 to 50 mononuclear leukocytes/mm³ of CSF.

Electrodiagnostic features strongly supportive of the diagnosis. Approximately 80 percent of patients will have evidence of nerve conduction slowing or blockage at some point during the illness. Conduction velocity is usually less than 60 percent of normal, but the