Definition | Diagnostic criteria | Epidemiology | Risk Factors | Pathophysiology | Presentation | Examination | Differential diagnosis | Investigations | Management | Prognosis | Golden Pearls | Quiz | References/Articles/Resources |
Definitions/Diagnostic criteria (UpToDate, 2021; Peña, Moreno & Gutierrez-Alvarez, 2015)
Guillain–Barre syndrome (GBS) is a cellular and humoral autoimmune disorder in which the body generates autoantibodies that attack peripheral nerve components. Acute immune-mediated poly neuropathies are classified under the eponym GBS.
It is characterised by symmetrical progressive weakness typically beginning in the lower limbs and accompanied by hyporeflexia or areflexia
Pain is a common symptom in patients with Guillain–Barre syndrome. Intensity is moderate to severe in most cases and pain may persist after resolution of the disease.
Epidemiology (Peña, Moreno & Gutierrez-Alvarez, 2015)
Incidence rate is 1.1 to 1.8 new cases per 100000 population per year. More common with increasing age.
Pain occurs in >75% of patients with GBS
Men are 1.5 times more likely to develop the syndrome
2/3rds of all cases follow URTI or diarrhoea illness. Most commonly Campylobacter jejuni (30% of all cases), cytomegalovirus (up to 10% of cases), Epstein–Barr virus, varicella-zoster virus, and Mycoplasma pneumoniae
Risk factors
Pathophysiology (Peña, Moreno & Gutierrez-Alvarez, 2015)
Cerebrospinal fluid from patients usually displays albuminocytological dissociation (increased protein level with normal cell count); this is more frequent after 2 weeks.
Little is known about the pathophysiology of pain in these patients; however, presence of multiple types of pain (back and sciatic pain, meningeal signs, dysaesthesia and paraesthesia, muscle pain, arthralgia, visceral pain, etc.)5 suggests that its origin is both nociceptive and neuropathic.
Three causes for neuropathic pain have been established in models:
(1) Demyelination and degeneration of sensory nerves
(2) Autoimmune inflammation of the peripheral nervous system due to activation of T-cells, antigen-presenting cells, and macrophages that release such proinflammatory cytokines as IL-18 and TNF-α
(3) Increased levels and activation of microglia in the central nervous system. One proposed explanation for back pain and sciatica is entrapment neuropathy, and nociceptive pain may be linked to inflammation of nerve roots and peripheral nerves in the acute phase of the disease.
Presentation
Pain is the most common symptom of GBS; it presents in up to 72% of cases including the pure motor variants. It is usually of moderate to severe intensity and can arise at any stage in the disease.
Pain is often underdiagnosed for two main reasons: lack of knowledge about the disease, and the fact that some of these patients are admitted to the intensive care unit (ICU) for ventilatory support, which makes it impossible for them to explain their physical state.
Neuropathic
burning, tingling, shock-like
Back and leg pain
Aching, deep throbbing pain with radicular features in the thigh/calves
Visceral pain
MSK pain (cramping)
Examination
Differential diagnosis
Investigations
Electrophysiological studies are useful not only for confirming the diagnosis but also for identifying the disease subtype as acute inflammatory demyelinating polyradiculoneuropathy, acute sensorimotor axonal neuropathy, acute motor axonal neuropathy, or acute sensory axonal neuropathy.
Treatment
Disease management includes implementing support measures and immunotherapy with IVIg or plasmapheresis
Evidence for the most appropriate analgesic therapies in GBS are lacking. There are some favourable reports for carbamazepine and gabapentin - with gabapentin having better evidence of lowering pain scores.
Interestingly, the methylprednisolone used did not have a positive effect on pain reduction (though evidence was poor).
Other medications trialled include: morphine, dexamethasone and remifentanil - with case reports of improved pain
In a case report of a patient with Miller Fisher syndrome, NSAIDs were shown to be ineffective for pain management
Prognosis
GBS usually has a good prognosis and relapses are rare.
However, approximately 2% of patients die and 20% are left with severe disabilities
Golden pearls
Quiz
References / Articles / Resources
UpToDate - Guillain-Barré syndrome in adults: Clinical features and diagnosis (2018 - accessed 2021)
Peña, L., Moreno, C. B., & Gutierrez-Alvarez, A. M. (2015). Pain management in Guillain–Barre syndrome: a systematic review. Neurología (English Edition), 30(7), 433-438.
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