Guillain-Barre Syndrome Flashcards
what is the definition of GBS?
Guillain-Barre syndrome (GBS) is an acute inflammatory neuropathy. It is a clinically defined syndrome characterised by motor difficulty, absence of deep tendon reflexes, paraesthesias without objective sensory loss, and increased cerebrospinal fluid albumin with a normal cell count (albuminocytological dissociation). Acute inflammatory demyelinating polyradiculoneuropathy is the most commonly encountered variant
what is the epidemiology of GBS?
Slightly more common in men
Western hemisphere
what is the aetiology of GBS?
Guillain-Barre syndrome (GBS) is characterised by an immune-mediated attack on the myelin sheath or Schwann cells of sensory and motor nerves. This is due to cellular and humoral immune mechanisms, frequently triggered by an antecedent infection.
Two-thirds of patients have a history of gastroenteritis or influenza-like illness weeks before onset of neurological symptoms.
GBS is associated with outbreaks of Zika virus. As with other viral infections, there are occasional reports of GBS associated with coronavirus disease 2019 (COVID-19) infection, although this is very rare.
what are the risk factors for GBS?
Preceding viral illness
Preceding bacterial infection
Preceding mosquito-borne viral infection
Hep E
what is the pathophysiology of GBS?
Guillain-Barre syndrome (GBS) is an autoimmune disorder in which antibodies to gangliosides play an important role. They trigger an attack on various components of peripheral nerve myelin and sometimes even the axons. The mechanism for this is unclear but may be a consequence of molecular mimicry, whereby antibodies or T cells stimulated by antigenic epitopes on the infecting microbe cross-react with neural epitopes. Host-generated antibodies against GM1-, GD1a-, GalNac-Gd1a-, and GD1b-related gangliosides are strongly associated with a subtype of AMAN, AMSAN, and Miller-Fisher syndrome (MFS). AMAN is strongly associated with antibodies against GM1, GD1a, GalNac-GDa1, and GD1b.
what are the key presentations of GBS?
Risk factors Muscle weakness Paraesthesia Back and leg pain Respiratory distress Speech problems areflexia/hyporeflexia Facial weakness Bulbar dysfunction causing oropharyngeal weakness Extraocular muscle weakness Facial drop Diplopia Dysarthria Dysphagia Dysautonomia Pupillary dysfunction, ophthalmoplegia
what are the signs of GBS?
Areflexia/hyporeflexia Diplopia Dysarthria Dysphagia Dysautonomia Pupillary dysfunction, ophthalmoplegia
what are the symptoms of GBS?
Muscle weakness Paraesthesia Back and leg pain Respiratory distress Speech problems Facial weakness Bulbar dysfunction causing oropharyngeal weakness Extraocular muscle weakness
what are the first line and gold standard investigations for GBS?
Nerve conduction studies - prolonged distal and F-wave latencies and reduced conduction velocities; H reflex prolonged or absent
Lumbar puncture - elevated CSF protein, normal/slightly high lymphocytes (<50 cells/mm³)
LFTs - elevated aspartate aminotransferase and alanine aminotransferase as high as 500 U/L; bilirubin may be transiently elevated but rarely high enough to cause jaundice
Spirometry - may show reduced vital capacity, maximal inspiratory pressure, or maximal expiratory pressure
what are the differential diagnoses for GBS?
Transverse myelitis Myasthenia gravis LEMS Botulism Polymyositis Vasculitic neuropathy
how is GBS managed?
No IgA deficiency or renal failure:
Intravenous immunoglobulin, plasma exchange
With IgA deficiency or renal failure:
Plasma exchange
how is GBS monitored?
Most patients show continued disease progression for up to 2 weeks, followed by a plateau phase of 2 to 4 weeks, and then recovery of function. Patients should have follow-up within 2 weeks after the acute syndrome to evaluate for relapse, at which point plasma exchange can be considered. Thereafter, follow-up is every 4 to 6 weeks for 6 months, then to 6 months for 1 year, and then yearly
what are the complications of GBS?
Approximately 20% to 30% of patients with GBS will develop respiratory muscle weakness requiring ventilation.
Respiratory failure
Bladder areflexia
Adynamic ileus
what is the prognosis of GBS?
The overall prognosis for patients with GBS is good, with approximately 85% of survivors making a good functional recovery. Miller-Fisher syndrome has a better prognosis than other GBS subtypes, and most patients recover completely without treatment within 6 months.
