Guillain–Barré Syndrome

Guillain–Barré Syndrome (GBS) is an autoimmune disease affecting the peripheral nervous system, characterised by rapid-onset muscle weakness due to immune-mediated damage. Commonly referred to as Guillain–Barré–Strohl syndrome or Landry's paralysis, this condition can have a profound impact on neuromuscular function.

Signs and Symptoms

The initial symptoms of GBS include numbness, tingling, and pain, which are often followed by symmetrical muscle weakness in the legs and arms. The weakness can progress over hours to weeks, sometimes affecting the muscles of the neck and cranial nerves, leading to facial muscle weakness, swallowing difficulties, and occasionally eye muscle weakness.

In severe cases, the condition can progress to respiratory failure, necessitating mechanical ventilation. Autonomic dysfunction, affecting heart rate and blood pressure, is also common.

Causes

While the precise cause of GBS is unknown, it is often triggered by infectious agents such as Campylobacter jejuni or cytomegalovirus. Sometimes, it can follow surgery or vaccination. The underlying mechanism involves the immune system mistakenly attacking the peripheral nerves, damaging their myelin insulation.

Pathophysiology

GBS involves an immune attack on the peripheral nervous system. In the demyelinating variant, white blood cells target the myelin sheath of nerve cells. In the axonal variant, antibodies and complement proteins attack the axon membrane.

Diagnosis

Diagnosis is based on clinical features such as rapid muscle paralysis and absent reflexes, along with supportive tests like cerebrospinal fluid analysis and nerve conduction studies. Elevated protein levels in cerebrospinal fluid, with few white blood cells, is a characteristic finding. Nerve conduction studies help distinguish between different subtypes of GBS.

Spinal Fluid

Cerebrospinal fluid analysis typically shows elevated protein levels (>0.55 g/L) with fewer than 10 white blood cells per cubic millimetre, distinguishing GBS from other conditions.

Neurophysiology

Nerve conduction studies and electromyography can identify the type of nerve involvement, whether demyelinating or axonal.

Clinical Subtypes

Several subtypes of GBS exist, including:

• Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP): Most common in Europe and North America.
• Acute Motor Axonal Neuropathy (AMAN): More common in Asia and Central/South America.
• Miller Fisher Syndrome: Characterised by ataxia, eye muscle weakness, and areflexia.
• Pharyngeal-Cervical-Brachial Variant: Affects throat, face, neck, and shoulder muscles.

Treatment

Immunotherapy

The main treatments are plasmapheresis and intravenous immunoglobulins (IVIG), which help reduce the immune attack on the nervous system. Both treatments are equally effective, but IVIG is often preferred due to ease of administration and fewer complications.

Respiratory Failure

Mechanical ventilation may be required for those with respiratory muscle weakness. Spirometry tests help anticipate the need for ventilatory support.

Pain

Pain management varies, but there is insufficient evidence to recommend one specific type of pain medication over another.

Rehabilitation

Post-acute phase rehabilitation is very important and involves a multidisciplinary team to improve activities of daily living. Physical therapy, occupational therapy, speech-language pathology, and psychological support are integral to recovery.

Prognosis

The prognosis varies, with recovery taking weeks to years. About 5% of patients may die from complications such as severe infections, blood clots, or cardiac arrest. Long-term outcomes can include chronic pain, fatigue, and impaired quality of life.

Epidemiology

GBS is rare, with an incidence of 1–2 cases per 100,000 people annually. The risk increases with age and is more common in men. Subtype distribution varies geographically, with AIDP being more common in Europe and North America, and AMAN more prevalent in Asia and Central/South America.

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Self-assessment MCQs (single best answer)

Which of the following is a common initial symptom of Guillain–Barré Syndrome (GBS)?

What is the most common subtype of GBS in Europe and North America?

Which infectious agent is most commonly associated with triggering GBS?

What is the hallmark finding in cerebrospinal fluid (CSF) analysis for diagnosing GBS?

Which treatment is commonly used to reduce the immune attack on the nervous system in GBS?

Which subtype of GBS is characterised by ataxia, eye muscle weakness, and areflexia?

What system does Guillain–Barré Syndrome primarily affect?

Which test helps anticipate the need for ventilatory support in GBS patients?

What is the incidence rate of GBS?

Which of the following is a potential complication of severe GBS?