Guillain-Barre Syndrome
An acute or subacute polyneuropathy that can follow minor infective illnesses, inoculations, surgical procedures or may occur without obvious precipitants.
Etiology
- Autoimmune process: development of antibodies to the myelin of the peripheral nerves.
- Viral and other infections initiate the sensitization and trigger the autoimmune process (Epstein-Barr virus, Mycoplasma pneumoniae)
Clinical features
- Sensory symptoms appear at the onset e.g. spontaneous pain and paresthesia of the limbs.
- Sensory loss – hypoesthesia, anaesthesia.
- Often begins with myalgia or paresthesias of the lower limbs followed by weakness.
- Lower limb weakness ascends to involve pelvic girdle, abdominal, thoracic, and upper limb muscles → total motor paralysis with death from respiratory failure
- Symmetrical weakness of muscles with loss of tone and flaccidity.
- Tendon reflexes are reduced and later absent.
- The 7th cranial nerve is frequently involved, producing bilateral facial weakness. Dysarthria, dysphagia, and diplopia develop in severe cases.
- LANDRY’S SYNDROME: particularly virulent form of Guillan-Barre. Rapidly progressive ascending paralysis, engagement of respiratory muscles, respiratory failure, intubation, artificial ventilation.
Complications
- Respiratory impairment and respiratory failure (Landry’s ascending paralysis)
- Bulbar palsy (dysarthria, dysphagia, dysphonia) when bilateral facial weakness is present
- Autonomic instability may present as urinary retention in the early stages of the disease.
- Pain presenting as myalgia in the lower limbs is an early symptom in some cases
- Secondary infection is a risk with pneumonia complicating respiratory insufficiency and increased risk of urinary tract infection and infected decubitus ulcers.
- Immobility predispose to deep venous thrombosis and pulmonary embolism
Diagnosis
- CSF has a characteristic abnormality (termed cytoalbuminologic dissociation); normal cell count but high protein.
- EMG may reveal marked slowing of motor and sensory conduction velocity or evidence of denervation and axonal loss.
Treatment
- Plasmapheresis is the filtering of blood and removing harmful antibodies. Appears to reduce recovery time and may decrease the likelihood of residual neurologic deficits. Best started early, and indicated in patients with severe or rapidly progressive deficit or respiratory compromise.
- Intravenous immunoglobulin preferred to plasmapheresis in adults with cardiovascular instability and in children; two therapies are not additive.
Prognosis
- The disorder is self-limiting, and improvement occurs over the weeks or months after onset.
- 70% of patients recover completely, 25% have mild neurologic deficits, and 5% die.
- Prognosis is poorer when there is evidence of preceding Campylobacter jejuni infection, and a more protracted course and less complete recovery are also likely when axonal degeneration rather than demyelination is the primary pathology.