Guilain- Barre Syndrome
It is an acquired demyelinating disorder of the peripheral nervous system with progressive motor weakness, paresthesias and areflexia.
Most cases occur within few weeks of a preceeding infection (URTI, gastroenteritis, immunisations, surgery etc) that triggers autoimmune response with demyelination of peripheral nerves.
Clinical features:
– Ascending Motor Weakness(progressive over days) may present as a disturbance of gait or acute ataxia.
– Symmetrical weakness (more distally), usually ascends from legs to arms and may involve truncal and finally bulbar muscles
– Cranial nerve palsiesare also common- especially 7th, 9th& 10thwith dysphagia
– Respiratory paralysis in some cases
– (If extraocular muscle involvement, consider Miller-Fisher variant)
– Symmetric areflexiaor marked hyporeflexia
– Sometimes, loss of position and vibratory sensation; paresthesia or backache.
– Transient autonomic dysfunctioncan manifest with bowel and bladder dysfunction or cardiovascular instability (hypertension, orthostatic hypotension, or tachyarrhythmia)
Investigations:
– Cerebral Spinal Fluid analysis may be normal in first week, so preferably done at 10 – 14 days after onset of symptoms.
– CSF shows dissociative increase in protein with only slight increased cell count (<10 cells/ul)
– Nerve Conduction Velocity may be reduced during first 2 weeks due to demyelination in peripheral nerves.
– This may involve motor and sensory nerves (distal > proximal initially)
– EMG is normal
Management:
– Supportive care requiring high dependency / intensive care setting to monitor cardiovascular, respiratory & neurological status
– Involve intensive care, Neurologist, Physiothapist as appropriate
– Intubation & ventilation required for respiratory failure caused by neuromuscular weakness (when shoulder weakness/ facial weakness/ dysphagia). This may last few weeks & tracheostomy may be required if needing prolonged ventilation.
– IVIG treatment improved recovery if administered early, within first 2 weeks
– Plasmapheresis is also effective where available
Prognosis:
– Most cases have a benign clinical course with recovery with 2-3 weeks with recovery of muscle function
– Complete recovery seen in half the cases by 6 months and majority within 12 months
– About 10% have residual weakness/ symptoms & few can relapse.
– Rare manifestations include Chronic Relapsing Polyradiculoneuropathy
Miller Fisher syndrome is also autoimmune neuropathy affecting the cranial nerves (especially ophthalmoplegia), with areflexia and ataxia but no weakness.