Author Interviews, Neurological Disorders, Zika / 06.02.2016
Incidence of Guillain-Barré Syndrome Rising As Zika Spreads
MedicalResearch.com Interview with:
Dr. Kenneth C. Gorson, MD
President Elect GBS|CIDP Foundation International Global Medical Advisory Board
Guillain-Barre syndrome (GBS)
Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
Medical Research: What is Guillain-Barré Syndrome? What are the main symptoms?
Dr. Gorson: Guillain-Barré Syndrome (GBS) is an immune mediated disorder affecting the peripheral motor and sensory nerves and nerve roots, and is the most common cause of rapidly progressive generalized paralysis in western countries. It is characterized by acute or subacute, progressive, symmetrical limb weakness with distal numbness or tingling in the arms and legs, and reduced or absent deep tendon reflexes in previously healthy patients. Patients notice the sudden onset of difficulty walking, climbing stairs, carrying objects and impaired fine motor skills. Balance is impaired due to sensory loss or weakness and a minority of patients develop facial weakness, trouble speaking and swallowing, and double vision. Severely affected patients may require ventilator support due to respiratory muscle weakness. Symptoms worsen over days to weeks, and most patients reach a maximum deficit (nadir) by 4 weeks, followed by a plateau phase for weeks to months, and then a recovery phase over additional weeks to months. Approximately 80 percent of patients recover to walk with minimal or no residual symptoms or functional disability. Maximal improvement usually occurs by one year, but more severely affected patients may continue to observe subtle improvements for several years after symptom onset.
In approximately two thirds of affected patients there is some preceding triggering event, classically a viral syndrome manifest as a transient upper respiratory or gastrointestinal illness with fever that resolves uneventfully prior to the onset of the neuropathy. Current evidence indicates the pathophysiology of GBS is related to molecular mimicry, where the patient's antibody response to the preceding infection interacts with a variety of antigens on peripheral nerve myelin or axons producing a generalized but multifocal inflammatory demyelinating process and associated axonal loss in some instances.
The diagnosis is established with nerve conduction studies and electromyography, which shows features indicative of a demyelinating neuropathy affecting multiple motor nerves in the arms and legs. The cerebrospinal fluid protein level is elevated without a cellular response (cyto-albuminological dissociation) in up to 80 percent of patients when performed in the first week of the illness.
Treatment is directed toward the immune response, and several large randomized controlled trials have demonstrated that intravenous immunoglobulin and plasma exchange hasten recovery, and both treatments have similar efficacy.
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