Guillain-Barré syndrome (GBS) is defined as heterogeneous group of autoimmune polyradiculopathies, involving sensory, motor and autonomic nerves. It is the most common cause of rapidly progressive flaccid paralysis 2.
Most cases preceded by upper respiratory tract infections or diarrhea 1-3 weeks before its onset, most commonly caused by Campylobacter jejuni (25-40% of patients are seropositive) 1,3. Molecular mimicry with the bacterial agents is thought to cause the autoimmunity.
Other predisposing factors include recent surgery, lymphoma and systemic lupus erythematosus (SLE) 2.
Classical presentation of GBS includes symmetrical ascending muscle paresis or palsy, areflexia or hyporeflexia along with variable degree of sensory or autonomic involvement.
Several subtypes have been described including:
- acute inflammatory demyelinating polyradiculoneuropathy (AIDP)
- axonal subtypes
- regional GBS syndromes
Guillain–Barré syndrome is diagnosed by combination of clinical presentation, CSF study and electrophysiological criteria.
CSF abnormalities are characterized by increase protein without pleocytosis, which is a non-specific finding, seen in many of the conditions which mimic GBS on imaging and clinically 1-2.
Nerve conduction abnormalities include slow or blocked nerve conduction, prolongation of distal latency and f-waves.
Chronic inflammatory demyelinating polyneuropathy (CIPD) is considered the chronic counterpart to GBS.
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Radiological studies are ordered to exclude other causes and in cases where nerve conduction studies and CSF examination are equivocal. MRI of the spine is most useful helps excluding other etiologies such as transverse myelitis and compressive causes of polyradiculopathy.
It is essential that contrast be administered if the diagnosis is suspected as non-contrast sequences are essentially normal 2.
Typical findings in Guillain–Barré syndrome are surface thickening and contrast enhancement on the conus medullaris and the nerve roots of the cauda equina 2.
The most common site of enhancement in Guillain–Barré syndrome is considered to be anterior nerve roots, although enhancement of the posterior nerve roots is also seen 2.
In the brain the facial nerve (CN VII) is the most commonly affected 1.
Treatment and prognosis
Guillain–Barré syndrome is primarily managed with IV immunoglobulins or plasmapheresis along with supportive measures, which can speed up recovery 1. Typically improvement occurs after a number of weeks to months 1 although there is significant mortality (3-10%) 5.
History and etymology
The syndrome was named after Georges Guillain (1876-1961) and Jean Alexandre Barré (1880-1967), French neurologists. André Strohl (1887-1977), a French physiologist, worked together with the both neurologists and is third author in the description done in 1916, and for this reason the syndrome is also referred as Guillain-Barré-Strohl syndrome.
The differential is essentially that of nerve root / cauda equina enhancement:
- AIDS-related polyradiculopathy
- arachnoiditis from any cause (e.g. post operative, or post intrathecal injection)
- leptomeningeal carcinomatosis and lymphoma
chronic inflammatory demyelinating polyneuropathy (CIDP)
- actue presentation of CIPD can be similar to GBS
- difficult to differentiate in the first 6 weeks
- after 6-8 weeks GBS should be improving whereas CIDP will demonstrate chronic inflammation 4
- Lyme disease
- rabies encephalitis (paralytic variant): similar presentation, but more fulminant course resulting in rapid demise in almost all cases