What is the most appropriate management for a patient who develops Guillain‑Barré syndrome after a viral infection?

Management of Guillain-Barré Syndrome Following Viral Infection

Initiate intravenous immunoglobulin (IVIg) at 0.4 g/kg/day for 5 consecutive days (total dose 2 g/kg) in any patient unable to walk unaided within 2-4 weeks of symptom onset, while simultaneously providing intensive supportive care with continuous respiratory and autonomic monitoring. 1, 2

Immediate Assessment and Stabilization

Critical Life-Threatening Evaluation

• Assess respiratory function immediately using vital capacity, negative inspiratory force (NIF), and maximum inspiratory/expiratory pressures at presentation and serially. 2 Apply the "20/30/40 rule": the patient is at risk of respiratory failure if vital capacity <20 ml/kg, maximum inspiratory pressure <30 cmH₂O, or maximum expiratory pressure <40 cmH₂O. 2
• Approximately 20% of patients develop respiratory failure requiring mechanical ventilation, which can occur rapidly and sometimes without obvious dyspnea. 2 Single breath count ≤19 predicts need for mechanical ventilation. 2
• Perform electrocardiography and continuously monitor heart rate and blood pressure for arrhythmias and blood pressure instability, as autonomic dysfunction is common and can include blood pressure/heart rate instability, pupillary dysfunction, and bowel/bladder dysfunction. 1, 2

Admission Criteria

• Grade 2 (moderate) disease: Patients with some interference with activities of daily living require neurology consultation and close monitoring. 2
• Grade 3-4 (severe) disease: Admit to an inpatient unit with capability for rapid transfer to ICU-level monitoring for patients with severe weakness limiting self-care, any dysphagia, facial weakness, respiratory muscle weakness, or rapidly progressive symptoms. 2

Diagnostic Workup

Essential Testing

• Obtain neurology consultation for every suspected GBS case. 2 The diagnosis can be challenging owing to heterogeneity in clinical presentation and lack of highly sensitive biomarkers. 1
• Cerebrospinal fluid analysis: Look for albumino-cytological dissociation (elevated protein with normal cell count), though this may be absent in the first week—do not dismiss GBS based on normal CSF protein early in the disease course. 1, 2 Also analyze for cell count and differential, cytology, glucose, and viral/bacterial cultures. 2
• Electrodiagnostic studies (nerve conduction studies and EMG) to support diagnosis and classify the neuropathy pattern. 1, 2 Look for the "sural sparing pattern" (normal sural sensory nerve action potential with abnormal median/ulnar responses), which is typical for GBS. 2
• MRI of spine with and without contrast to rule out compressive lesions and evaluate for nerve root enhancement/thickening. 2
• Serum antiganglioside antibody tests for GBS subtypes (e.g., anti-GQ1b for Miller Fisher variant). 2

Screen for Reversible Causes

• Measure HbA1c, vitamin B12, TSH, vitamin B6, folate, serum protein electrophoresis, and creatine kinase (CK). 2 Elevated CK suggests muscle involvement and may indicate the acute motor axonal neuropathy (AMAN) variant. 2

First-Line Immunotherapy

Treatment Selection and Timing

Both IVIg and plasma exchange are equally effective when initiated within 2 weeks of symptom onset, with no significant outcome differences between the two treatments during this critical window. 3, 4 However, IVIg is generally preferred due to easier administration, wider availability, and significantly higher completion rates. 3

IVIg Protocol

• Administer IVIg 0.4 g/kg/day for 5 consecutive days (total dose 2 g/kg) for patients unable to walk unaided within 2-4 weeks of symptom onset. 1, 2, 4
• Use ideal body weight for dosing in obese patients. 2
• Do not wait for antibody test results before starting treatment if GBS is suspected. 2

Plasma Exchange Alternative

• Plasma exchange 200-250 ml/kg over 4-5 sessions is equally effective to IVIg. 1, 2, 4 For severe GBS requiring ventilation, 4-6 sessions are recommended, with 4 sessions being effective and 6 sessions providing no additional benefit over 4. 3, 5
• Plasma exchange requires specialized equipment and vascular access but may be more cost-effective in resource-limited settings. 6

What NOT to Do

• Corticosteroids alone are NOT recommended for idiopathic GBS. 2, 7, 4
• Do not combine plasma exchange followed by IVIg or vice versa, as sequential treatment is not beneficial. 4

Supportive Care and Monitoring

Respiratory Surveillance

• Conduct frequent pulmonary function testing with serial vital capacity and NIF measurements to detect early respiratory compromise. 2
• Perform daily neurologic examinations to track disease progression and response to therapy. 2

Pain Management

• Use gabapentinoids (gabapentin, pregabalin) or duloxetine for neuropathic pain—these are preferred over opioids. 1, 2 Gabapentin can be initiated alongside IVIg without contraindication or interaction, as they work through completely different mechanisms. 2
• Do not delay gabapentin initiation waiting for IVIg to "work first", as pain control should begin immediately as part of comprehensive supportive care. 2

Autonomic Dysfunction Management

• Monitor blood pressure, heart-rate variability, pupillary responses, and bowel/bladder function to identify autonomic instability. 2
• Treatment of constipation/ileus is essential. 2

Medications to Avoid

Avoid drugs that impair neuromuscular transmission: β-blockers, intravenous magnesium, fluoroquinolones, aminoglycosides, and macrolides, as they may exacerbate weakness. 2

Managing Treatment Response and Complications

Expected Response Timeline

• Approximately 40% of patients do not improve in the first 4 weeks following treatment—this does not necessarily mean treatment failed, as progression might have been worse without therapy. 1, 2, 3
• Most patients reach maximum disability within 2 weeks of onset, defining the critical treatment window. 2, 3

Treatment-Related Fluctuations (TRFs)

• TRFs occur in 6-10% of patients, defined as disease progression within 2 months following initial treatment-induced improvement or stabilization. 1, 2, 3
• Repeating a full course of IVIg or plasma exchange is common practice for TRFs, although evidence supporting this approach is lacking. 1

Diagnosis Revision

• Consider changing diagnosis to acute-onset chronic inflammatory demyelinating polyneuropathy (CIDP) if progression continues after 8 weeks from onset or if the patient has three or more TRFs—this occurs in approximately 5% of patients initially diagnosed with GBS. 1, 2

Prognosis and Long-Term Management

Recovery Expectations

• 80% of patients regain independent walking ability at 6 months. 1, 2 Recovery can continue for more than 3 years, with improvement possible even more than 5 years after onset. 1, 2
• Mortality is 3-10%, primarily from cardiovascular and respiratory complications that can occur in both acute and recovery phases. 1, 2, 8
• Advanced age and severe disease at onset are risk factors for poor outcome. 1, 2

Rehabilitation Planning

• Arrange a rehabilitation programme with a rehabilitation specialist, physiotherapist, and occupational therapist as a crucial step towards recovery. 1, 2
• Exercise programmes including range-of-motion exercises, stationary cycling, walking, and strength training improve physical fitness, walking ability, and independence in activities of daily living. 1, 2
• Monitor exercise intensity closely as overwork can cause fatigue. 1

Long-Term Complications

• Fatigue is found in 60-80% of patients and is often one of the most disabling complaints. 1
• Severe pain is reported in at least one-third of patients 1 year after disease onset and can persist for >10 years. 1

Recurrence and Vaccination

• Recurrence is rare (2-5% of patients) but higher than the general population lifetime risk (0.1%). 1, 2 Prior GBS is not a strict contraindication for vaccination, but discussion with experts is useful for patients diagnosed with GBS <1 year before planned vaccination. 1

Special Consideration: Immune Checkpoint Inhibitor-Related GBS

If GBS develops in the context of immune checkpoint inhibitor therapy:

• Permanently discontinue the immune checkpoint inhibitor. 1, 2
• Consider adding concurrent corticosteroids (methylprednisolone 2-4 mg/kg/day) to IVIg or plasma exchange. 1, 2
• For Grade 3-4 severity, pulse corticosteroid therapy (methylprednisolone 1 g/day for 5 days) may be employed as an adjunct. 1, 2