What is the recommended evaluation, treatment, and supportive care for a patient presenting with acute ascending symmetric weakness suggestive of Guillain‑Barré syndrome?

Guillain-Barré Syndrome: Evaluation, Treatment, and Supportive Care

Immediate Assessment Priorities

Obtain neurology consultation immediately for every suspected GBS case, and assess respiratory function and autonomic stability at presentation—these determine mortality risk and need for ICU-level care. 1, 2

Respiratory Monitoring

• Measure vital capacity, negative inspiratory force (NIF), and maximum inspiratory/expiratory pressures at presentation and serially 2
• Apply the "20/30/40 rule": 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
• Single breath count ≤19 predicts need for mechanical ventilation 2
• Approximately 20% of patients develop respiratory failure requiring mechanical ventilation, which can occur rapidly and sometimes without obvious dyspnea 2, 3

Cardiovascular and Autonomic Monitoring

• Perform electrocardiography and continuously monitor heart rate and blood pressure for arrhythmias and blood pressure instability 2
• Monitor for dysautonomia including blood pressure/heart rate instability, pupillary dysfunction, and bowel/bladder dysfunction 1, 4

Neurological Examination

• Grade muscle strength using Medical Research Council scale in neck, arms, and legs 2
• Assess functional disability using GBS disability scale 2
• Test swallowing and coughing ability to identify aspiration risk 2
• Assess for facial weakness and ophthalmoplegia 2
• Check for corneal reflex in patients with facial palsy to prevent corneal ulceration 2
• Look for bilateral ascending weakness typically starting in the legs and progressing to arms and cranial muscles 4
• Document diminished or absent reflexes, which are present in most patients at presentation and almost all at nadir 4

Diagnostic Workup

Laboratory Investigations

Order complete blood count, glucose, electrolytes, kidney function, and liver enzymes to exclude metabolic or electrolyte dysfunction as causes of weakness. 1, 2

• Measure serum creatine kinase (CK)—elevation suggests muscle involvement and may indicate the acute motor axonal neuropathy (AMAN) variant 2
• Discontinue statins if present, as they can cause elevated CK 2

Cerebrospinal Fluid Analysis

Perform lumbar puncture to look for albumino-cytological dissociation (elevated protein with normal cell count), but do not dismiss GBS based on normal CSF protein in the first week. 1, 2, 5

• CSF protein elevation may not appear until the end of the first week and can persist until the third week 6
• Also analyze CSF for cell count and differential, cytology for malignant cells, glucose, and viral/bacterial cultures 2
• Marked CSF pleocytosis should prompt reconsideration of the diagnosis 1

Electrodiagnostic Studies

Obtain nerve conduction studies and EMG to support diagnosis and classify the neuropathy pattern. 1, 2, 5

• Look for sensorimotor polyradiculoneuropathy with reduced conduction velocities, reduced amplitudes, temporal dispersion, or conduction blocks 2
• "Sural sparing pattern" (normal sural sensory nerve action potential with abnormal median/ulnar responses) is typical for GBS 1, 2
• Electrodiagnostic measurements might be normal when performed early (within 1 week); repeat testing in 2-3 weeks if clinical suspicion remains high 2
• The pattern helps distinguish between AIDP (demyelinating), AMAN (motor axonal), and AMSAN (sensory-motor axonal) subtypes 2

Additional Testing

• 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 with ataxia and ophthalmoplegia) 2, 5
• Screen for reversible neuropathy causes: HbA1c, vitamin B12, TSH, vitamin B6, folate 2

Red Flags for Alternative Diagnoses

• Marked persistent asymmetry 1
• Bladder dysfunction at onset 1
• Marked CSF pleocytosis 1
• Progression continuing after 8 weeks from onset (consider acute-onset CIDP) 2, 5

First-Line Immunotherapy

Initiate intravenous immunoglobulin (IVIg) 0.4 g/kg/day for 5 consecutive days (total dose 2 g/kg) in patients unable to walk unaided within 2-4 weeks of symptom onset. 2, 3, 5

Alternative Treatment

• Plasma exchange 200-250 mL/kg over 4-5 sessions is equally effective 2, 3, 5
• For patients requiring mechanical ventilation, 4 sessions are sufficient 2

What NOT to Do

Corticosteroids alone are NOT recommended for idiopathic GBS. 2, 5, 7

• Sequential use of plasma exchange followed by IVIg (or vice-versa) has not shown benefit 2, 5
• Do not wait for antibody test results before starting treatment 1

Exception: Immune Checkpoint Inhibitor-Related GBS

• Permanently discontinue the immune checkpoint inhibitor 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 adjunct 1, 2

Admission Criteria and Level of Care

Grade 2 (Moderate Disease)

Patients with some limitation of daily activities require neurology consultation and close monitoring. 1, 2

Grade 3-4 (Severe Disease)

Admit to an inpatient unit capable of rapid transfer to ICU-level monitoring for patients with severe weakness limiting self-care, dysphagia, facial or respiratory muscle weakness, or rapidly progressive symptoms. 2, 3

• Even patients with moderate symptoms require neurology consultation and close monitoring 2
• All grades of GBS warrant workup and intervention given potential for progressive disease leading to respiratory compromise 2

Supportive Care

Pain Management

Use gabapentinoids (gabapentin or pregabalin) or duloxetine for neuropathic pain—these are preferred over opioids. 2, 5

• Gabapentin can be started concurrently with IVIg without drug interaction 2
• Tricyclic antidepressants or carbamazepine are alternative options 2, 5
• Pain affects approximately two-thirds of patients and can be muscular, radicular, or neuropathic 1, 4

Medications to Avoid

Avoid drugs that impair neuromuscular transmission: β-blockers, IV magnesium, fluoroquinolones, aminoglycosides, and macrolides. 2

Standard Preventive Measures

• Daily neurologic evaluation 2
• Treatment of constipation/ileus 2
• Pressure ulcer prevention 2
• Deep vein thrombosis prophylaxis 2
• Hospital-acquired infection prevention 2

Psychological Support

• Recognize that patients with GBS, even those with complete paralysis, usually have intact consciousness, vision, and hearing 2
• Screen for anxiety, depression, and hallucinations, which are frequent complications 2
• Be mindful of what is said at bedside and explain procedures to reduce anxiety 2

Treatment Response and Fluctuations

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. 2, 3, 8

Treatment-Related Fluctuations (TRFs)

• Occur in 6-10% of patients, defined as disease progression within 2 months following initial treatment-induced improvement or stabilization 2, 3, 5
• Repeating a full course of IVIg or plasma exchange is common practice for TRFs, although high-quality evidence is lacking 2, 5

When to Reconsider the Diagnosis

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

Prognosis and Long-Term Management

Expected Outcomes

• 80% of patients regain independent walking ability at 6 months 2, 5
• Recovery can continue for more than 3 years, with improvement possible even more than 5 years after onset 2, 5
• Mortality is 3-10%, primarily from cardiovascular and respiratory complications 2, 4, 5
• Advanced age and severe disease at onset are risk factors for poor outcome 2, 5

Prognostic Tools

• Use the modified Erasmus GBS outcome score (mEGOS) to predict probability of regaining walking ability 2, 5
• Use the modified Erasmus GBS Respiratory Insufficiency Score (mEGRIS) to assess risk of requiring artificial ventilation 5

Rehabilitation

Arrange a rehabilitation program with physiotherapist, occupational therapist, and rehabilitation specialist as a crucial step toward recovery. 2

• Exercise programs (range-of-motion, stationary cycling, walking, strength training) improve physical fitness, walking ability, and independence in activities of daily living 2
• Fatigue is reported in 60-80% of survivors and is a major disabling symptom 2
• Severe pain affects at least one-third of patients at 1 year and may persist for more than a decade 2

Recurrence and Vaccination

• Recurrence is rare (2-5% of patients) but higher than the background lifetime risk (0.1%) 2, 4
• Prior GBS is not an absolute contraindication to vaccination; however, vaccination within one year of a GBS episode should be discussed with specialists 2

Common Pitfalls to Avoid

• Do not dismiss GBS based on normal CSF protein in the first week 1, 2
• Do not dismiss GBS based on absent sural sparing in the first week—repeat testing in 2-3 weeks if clinical suspicion remains high 2
• Do not delay gabapentin initiation waiting for IVIg to "work first"—pain control should begin immediately 2
• Bilateral simultaneous facial weakness is extremely rare in Bell's palsy and should immediately raise suspicion for GBS 2
• Recognize that weakness spreading from legs to arms represents typical disease progression, not treatment failure, if occurring within the expected 2-4 week progressive phase 3