Guillain-Barré syndrome

1. History

• Key HPI: Ask about progressive weakness — onset, distribution (legs → arms → face), and rate of progression. Characterize numbness, tingling, paresthesias, and pain (often prominent, especially back/thigh pain early on). [2][4]
• Antecedent illness: Up to 76% report a preceding infection within 4 weeks — upper respiratory tract infection (35%), gastroenteritis (27%), or other viral illness. Specifically ask about diarrhea (Campylobacter), URI symptoms, and recent vaccinations or surgery. [1-2]
• Timing: Symptoms typically begin 1–6 weeks after the triggering event and progress over days to 4 weeks. [1-2]
• Functional impact: Can the patient walk unaided? Climb stairs? Swallow? Cough effectively? These determine treatment urgency. [5]
• Associated symptoms: Difficulty swallowing, facial droop (bilateral), diplopia, shortness of breath, urinary retention, constipation, orthostatic dizziness. [5-6]

2. Alarm Features

• Respiratory compromise: Dyspnea, inability to count to 20 in one breath, use of accessory muscles, paradoxical breathing — ~25% require mechanical ventilation. [2][7]
• Bulbar weakness: Dysphagia, drooling, weak cough → aspiration risk. [8]
• Rapid progression: Onset to inability to walk in <7 days predicts higher ventilation risk. [1][8]
• Autonomic instability: Labile blood pressure (swings >85 mmHg systolic), tachycardia/bradycardia, cardiac arrhythmias — can cause sudden cardiac arrest. [2][5]
• Bilateral facial weakness combined with limb weakness and areflexia. [8]

3. Medications

• Disease-modifying treatment:
  • IVIG: 0.4 g/kg/day × 5 days (total 2 g/kg) — preferred in most centers for convenience. [2][5]
  • Plasma exchange (PLEX): 5 sessions over 2 weeks, total exchange of ~5 plasma volumes. [2][5]
  • Both are equally effective and should be started within 2 weeks of symptom onset in nonambulant patients. [7]
• Corticosteroids alone are NOT effective and are not recommended for idiopathic GBS. Exception: ICI-related GBS, where IV methylprednisolone 1 g/day × 5 days may be added. [4-5][7]
• Do NOT combine PLEX followed by IVIG (or vice versa) — no added benefit, and PLEX after IVIG removes the immunoglobulin. [1][7]
• Pain management: Gabapentin, pregabalin, or carbamazepine for neuropathic pain; NSAIDs for nociceptive pain. Avoid opioids when possible (respiratory depression risk, ileus). [4-5][9]
• Use vasoactive medications and morphine derivatives with caution due to autonomic lability. [5]
• DVT prophylaxis: Subcutaneous heparin + compression stockings in nonambulant patients. [2]

4. Diet

• Assess swallowing function early — patients with bulbar weakness are at high aspiration risk and may require NPO status with nasogastric tube feeding. [2]
• Ensure adequate nutrition; prolonged ICU stays lead to catabolic state.
• Monitor for ileus (autonomic dysfunction) — may require bowel regimen and parenteral nutrition in severe cases. [5][10]
• No specific dietary triggers or restrictions for GBS itself.

5. Review of Systems

• Neurologic: Weakness pattern (ascending vs. descending), numbness/tingling, facial droop, diplopia, difficulty speaking/swallowing.
• Respiratory: Dyspnea, orthopnea, weak cough, inability to take deep breaths.
• Cardiovascular: Palpitations, lightheadedness, syncope (autonomic dysfunction).
• GI: Constipation, abdominal distension (ileus), nausea.
• GU: Urinary retention or incontinence.
• Pain: Back pain, limb pain, paresthesias — pain is present in >50% and may precede weakness. [9]

6. Collateral History and Family History

• Confirm timeline of symptom onset and progression from family/witnesses.
• Ask about recent travel (exposure to endemic infections like Zika, dengue). [1]
• Recent illness contacts, food exposures (undercooked poultry → Campylobacter). [2]
• Family history: GBS is not hereditary, but ask about autoimmune conditions and prior episodes of weakness.
• Prior GBS episodes (recurrence rate ~2–5%) — if recurrent, consider acute-onset CIDP. [11]

7. Risk Factors

• Preceding infections (strongest risk factor):
  • Campylobacter jejuni (most common, ~30%) — associated with axonal variants. [1-2]
  • Cytomegalovirus (~10%), Epstein-Barr virus, Mycoplasma pneumoniae, Zika virus, influenza, SARS-CoV-2. [1-2]
• Vaccinations: Very rare association; 1976 swine flu vaccine had highest risk (~1/100,000). Current influenza vaccines carry risk <1 per million. Ad26.COV2.S (Janssen) COVID vaccine showed a signal. [1][12-13]
• Surgery and immune checkpoint inhibitor therapy. [1]
• Demographics: Slightly more common in males (M:F ~1.78:1); incidence increases 20% per decade of age. [2]
• Comorbidities: Underlying autoimmune disease, recent surgical trauma. [14]

8. Differential Diagnosis

• Cannot-miss diagnoses:
  • Spinal cord compression/transverse myelitis — upper motor neuron signs, sensory level, urinary retention prominent early. [2]
  • Botulism — descending paralysis, pupil involvement, no sensory symptoms.
  • Myasthenia gravis — fluctuating weakness, fatigability, preserved reflexes.
  • Stroke (brainstem) — asymmetric, upper motor neuron signs. [15]
• Important mimics:
  • Hypokalemia — commonly overlooked; check electrolytes early. [2]
  • Acute myopathy/rhabdomyolysis — preserved reflexes, elevated CK.
  • Poliomyelitis/acute flaccid myelitis — asymmetric, pure motor, CSF pleocytosis.
  • Tick paralysis — ascending paralysis, search for tick.
  • Critical illness polyneuropathy — ICU setting.
  • Toxic neuropathies (heavy metals, organophosphates), porphyria, Lyme disease, diphtheria, vasculitis. [2][16]
• Distinguishing features of GBS: Symmetric ascending weakness + areflexia + distal paresthesias + antecedent illness + albuminocytological dissociation. [2][5]

9. Past Medical History

• Prior episodes of GBS or CIDP (if progression >8 weeks, reconsider acute-onset CIDP). [11]
• History of autoimmune diseases.
• Recent surgeries or immunizations.
• Immunocompromised state (HIV — can present with GBS but CSF may show pleocytosis).
• Chronic illnesses affecting respiratory reserve (COPD, obesity) — lower threshold for ICU monitoring.

10. Physical Exam

• Vital signs: Heart rate and blood pressure lability (autonomic dysfunction); respiratory rate, oxygen saturation. [5]
• Motor: Symmetric weakness — grade with MRC sum score (0–60). Typically proximal and distal, legs > arms initially. Check neck flexion strength. [5][8]
• Reflexes: Areflexia or hyporeflexia is the hallmark. Note: AMAN variant may have preserved or even brisk reflexes. [17]
• Sensory: Distal paresthesias, stocking-glove sensory loss; sensory exam may be normal in pure motor variants.
• Cranial nerves: Bilateral facial weakness (~50%), bulbar weakness (CN IX/X — gag reflex, palatal elevation, voice quality), ophthalmoplegia (Miller Fisher variant). [1]
• Respiratory: Count to 20 in one breath, assess cough strength, look for paradoxical abdominal breathing.
• Focused maneuvers: Single-breath count test, neck flexion against resistance (early predictor of respiratory failure). [8]

11. Lab Studies

• Lumbar puncture/CSF analysis: Classic finding is albuminocytological dissociation (elevated protein, normal WBC <10 cells/μL). CSF protein is often normal in the first week but elevated in >90% by week 2. Pleocytosis should raise concern for HIV, Lyme, CMV, or leptomeningeal disease. [2][5]
• Basic labs: CBC, CMP (rule out hypokalemia, hyponatremia/SIADH), CK (normal in GBS; elevated suggests myopathy), LFTs, ESR/CRP.
• Infectious workup: Campylobacter serology, CMV/EBV titers, Mycoplasma, HIV, Lyme (if endemic area).
• Anti-ganglioside antibodies: Anti-GM1 (AMAN), anti-GQ1b (Miller Fisher syndrome) — helpful but not required for diagnosis. [4][18]
• Pulmonary function: Serial NIF (negative inspiratory force) and FVC (forced vital capacity) — the most critical monitoring parameters. [4-5]

12. Imaging

• MRI spine with and without contrast: First-line to rule out compressive myelopathy or other structural lesions. May show cauda equina/nerve root enhancement (supportive but not specific for GBS). [4][11]
• MRI brain: Consider if Miller Fisher syndrome or Bickerstaff brainstem encephalitis is suspected. [11]
• Chest X-ray: Baseline and if respiratory compromise suspected (atelectasis, aspiration).
• Imaging is not required for diagnosis in classic presentations but is important to exclude mimics. [11]

13. Special Tests

• Nerve conduction studies (NCS)/EMG: Confirms peripheral neuropathy and classifies subtype (AIDP vs. AMAN vs. AMSAN). May be normal in the first few days — repeat at 2 weeks if initially equivocal. Findings include prolonged distal latencies, slowed conduction velocities, conduction block (AIDP), or reduced CMAP amplitudes (axonal). [1][15]
• Pulmonary function tests: Serial FVC and NIF every 2–4 hours during progressive phase. FVC <20 mL/kg → consider ICU; FVC <15 mL/kg → intubation criteria. [2]
• Prognostic scoring systems:
  • EGRIS (Erasmus GBS Respiratory Insufficiency Score): Predicts need for mechanical ventilation based on days from onset, MRC sum score, and facial/bulbar weakness. [1][19]
  • mEGOS (modified Erasmus GBS Outcome Score): Predicts ability to walk independently at 6 months. [1]
• Brighton Collaboration criteria: Standardized diagnostic certainty levels (1–4). [1]

14. ECG

• Obtain ECG on all patients — autonomic dysfunction causes cardiac complications in ~50%. [20]
• Findings to watch for:
  • Sinus tachycardia (most common). [20-21]
  • Sinus bradycardia → can progress to asystole (may require temporary pacemaker). [2][22]
  • ST-T wave changes, QT prolongation.
  • Blood pressure swings >85 mmHg systolic day-to-day may precede severe bradycardia. [2]
• Continuous cardiac monitoring is recommended during the acute progressive phase, especially in patients with severe weakness or autonomic symptoms. [5]

15. Assessment

• GBS is a clinical diagnosis supported by CSF and electrodiagnostic findings. Only 25–30% are diagnosed on the initial healthcare visit. [23]
• Severity stratification: Use the GBS disability scale (0 = healthy, 6 = dead). Patients scoring ≥3 (unable to walk unaided) require immunotherapy. [5]
• Subtypes: AIDP (most common in Western countries), AMAN (common in Asia, associated with Campylobacter), AMSAN, Miller Fisher syndrome (ophthalmoplegia + ataxia + areflexia). [1]
• Atypical presentations to recognize: Paraparetic GBS (legs only), pharyngeal-cervical-brachial variant, facial diplegia with paresthesias, pure sensory variant, autonomic-predominant. [1]
• Complications: Respiratory failure (~25%), autonomic instability (~20% serious), DVT/PE, aspiration pneumonia, neuropathic pain, SIADH, PRES. [1-2][10]

16. Treatment Plan

17. Disposition

• All suspected GBS patients should be admitted for monitoring until no further progression is confirmed. [2]
• ICU admission criteria: Rapidly progressive weakness, FVC <20 mL/kg, bulbar dysfunction, autonomic instability, need for or anticipated need for mechanical ventilation. [1-2]
• Step-down/floor: Stable patients past nadir with adequate respiratory function and no autonomic instability.
• Neurology consultation: Mandatory for all suspected cases. [4][23]
• Discharge criteria: Stable or improving strength, adequate respiratory function (FVC >25 mL/kg), able to swallow safely, pain controlled, rehabilitation plan in place.
• Consider acute-onset CIDP if progression continues beyond 8 weeks or if there are ≥3 treatment-related fluctuations. [11]

18. Follow Up / Return Precautions

• Follow-up: Neurology follow-up within 1–2 weeks of discharge; repeat NCS at 4–6 weeks to assess recovery trajectory and confirm subtype. [1]
• Rehabilitation: Most patients benefit from inpatient or outpatient rehabilitation. Recovery typically takes weeks to months; some patients improve for up to 1–2 years. [1]
• Return precautions — instruct patients/families to return immediately for:
  • Worsening weakness or new difficulty walking.
  • Difficulty breathing, swallowing, or speaking.
  • Dizziness, fainting, or palpitations.
  • Treatment-related fluctuation (secondary deterioration after initial improvement, occurs in ~10%). [1][5]
• Expected course: 77% walk independently at 6 months, 81% at 12 months. Residual fatigue is common (~67%). Neuropathic pain may persist. [1][7][24]
• Vaccination counseling: Future vaccinations are generally safe; the risk of GBS from natural infection exceeds the risk from vaccination. Shared decision-making is appropriate for influenza vaccination in patients with prior GBS. [1][13]