Neurology · Peripheral Neuropathy
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Guillain-Barré syndrome presents as an acute, ascending, symmetric muscle weakness often following a Campylobacter jejuni gastrointestinal infection.
The hallmark physical exam finding is areflexia or hyporeflexia in the affected limbs.
Lumbar puncture reveals albuminocytologic dissociation, characterized by elevated protein with a normal white blood cell count.
Autonomic instability, including cardiac arrhythmias and fluctuating blood pressure, is a common and potentially life-threatening complication.
The most critical initial step in management is assessing forced vital capacity or negative inspiratory force to monitor for respiratory failure.
First-line treatment consists of intravenous immunoglobulin (IVIG) or plasmapheresis to accelerate recovery.
Corticosteroids are not effective and are not recommended in the treatment of Guillain-Barré syndrome.
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A 34-year-old male presents to the emergency department with a 4-day history of progressive weakness starting in his feet and moving up to his thighs. He reports a diarrheal illness two weeks ago. On physical examination, he has symmetric 3/5 strength in the lower extremities and absent patellar and Achilles reflexes. He is currently able to speak in full sentences, but his forced vital capacity is 18 mL/kg.
What is the most appropriate next step in management?
Admission to the intensive care unit for elective endotracheal intubation and mechanical ventilation.
This patient exhibits classic signs of GBS (ascending paralysis, areflexia, post-infectious history). The clinical reasoning tests the 'bet' regarding respiratory failure, as a forced vital capacity <20 mL/kg indicates impending respiratory collapse requiring airway protection.
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Etiology / Epidemiology
Post-infectious autoimmune demyelination typically following Campylobacter jejuni or viral illness.
Clinical Manifestations
Ascending paralysis and areflexia are the hallmarks of this acute polyneuropathy.
Diagnosis
Lumbar puncture showing albuminocytologic dissociation is the diagnostic gold standard.
Treatment
First-line treatment is IVIG or plasmapheresis; avoid corticosteroids.
Prognosis
Monitor forced vital capacity to prevent respiratory failure; most recover within 6-12 months.
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Epidemiology & Etiology
Most common cause of acute flaccid paralysis in the post-polio era. Often triggered by molecular mimicry following Campylobacter jejuni infection, respiratory infections, or vaccinations. Can occur at any age but incidence increases with age.
Pertinent Anatomy
Involves the peripheral nervous system, specifically the myelin sheaths of spinal nerve roots and peripheral nerves. The sparing of the central nervous system explains the preservation of consciousness and sensory function relative to motor loss.
Pathophysiology
Autoantibodies target myelin antigens, leading to segmental demyelination of peripheral nerves. This results in slowed or blocked nerve conduction. In severe cases, secondary axonal degeneration occurs, which correlates with poorer long-term recovery.
Clinical Manifestations
Presents as symmetric, ascending muscle weakness starting in the distal lower extremities. Patients exhibit areflexia or hyporeflexia. Autonomic instability (arrhythmias, labile blood pressure) is a major cause of mortality. Sensory changes are usually mild, described as stocking-glove paresthesias.
Diagnosis
Lumbar puncture reveals albuminocytologic dissociation (elevated protein >400 mg/L with normal WBC count). Nerve conduction studies demonstrate decreased conduction velocity and prolonged distal latencies. Do not delay treatment for diagnostic testing if clinical suspicion is high.
Treatment
Initiate IVIG or plasmapheresis as soon as possible to shorten the disease course. Corticosteroids are ineffective and may worsen outcomes. Supportive care is critical; intubation is required if forced vital capacity drops below 15-20 mL/kg.
Prognosis
Most patients reach the nadir of weakness within 4 weeks. While 85% achieve full recovery, 10-20% have residual deficits. Respiratory failure is the primary cause of death; continuous pulse oximetry and serial pulmonary function tests are mandatory.
Differential Diagnosis
Botulism: descending paralysis and fixed dilated pupils
Myasthenia Gravis: fluctuating weakness and ptosis
Transverse Myelitis: sensory level and bowel/bladder dysfunction
Tick Paralysis: rapid recovery after tick removal
Polio: asymmetric weakness and fever