Guillain-Barré syndrome
Also known as infectious polyneuritis, Landry-Guillain-Barré syndrome, and acute idiopathic polyneuritis, Guillain-Barré syndrome is an acute, rapidly progressive, and potentially fatal form of polyneuritis that causes muscle weakness and mild distal sensory loss.
This syndrome can occur at any age but is most common between ages 30 and 50; it affects both sexes equally. Recovery is spontaneous and complete in about 95% of patients, although mild motor or reflex deficits in the feet and legs may persist. The prognosis is best when symptoms clear between 15 and 20 days after onset.
Causes
The precise cause of Guillain-Barré syndrome is unknown, but it may be a cell-mediated immune response with an attack on peripheral nerves in response to a virus. The major pathologic effect is segmental demyelination of the peripheral nerves.
Because this syndrome causes inflammation and degenerative changes in both the posterior (sensory) and the anterior (motor) nerve roots, signs of sensory and motor losses occur simultaneously.
Predisposing factors
About 50% of patients with Guillain-Barré syndrome have a recent history of minor febrile illness, usually an upper respiratory tract infection or, less commonly, gastroenteritis. When infection precedes the onset of Guillain-Barré syndrome, signs of infection subside before neurologic features appear.
Other possible precipitating factors include surgery, rabies or swine influenza vaccination, viral illness, Hodgkin’s or some other malignant disease, and systemic lupus erythematosus.
Signs and symptoms
Muscle weakness, the major neurologic sign, usually appears in the legs first (ascending type) and then extends to the arms and facial nerves within 24 to 72 hours. Sometimes, muscle weakness develops in the arms first (descending type) or in the arms and legs simultaneously. In milder forms of the disease, muscle weakness may affect only the cranial nerves or may not occur.
Paresthesia, another common neurologic sign, sometimes precedes muscle weakness but vanishes quickly. Some patients with the disorder never develop this symptom.
Other clinical features include facial diplegia (possibly with ophthalmoplegia [ocular paralysis]), dysphagia or dysarthria and, less commonly, weakness
of the muscles supplied by cranial nerve XI (spinal accessory nerve).
of the muscles supplied by cranial nerve XI (spinal accessory nerve).
Muscle weakness develops so quickly that muscle atrophy doesn’t occur, but hypotonia and areflexia do. Stiffness and pain in the form of a severe “charley horse” occur in many cases.
Three-phase course
The clinical course of Guillain-Barré syndrome is divided into three phases:
The initial phase begins when the first definitive symptom develops; it ends 1 to 3 weeks later, when no further deterioration is noted.
The plateau phase lasts from several days to 2 weeks.
