Progressive symptoms reaching maximum within 4 weeks.

Begins in legs → spreads upward to arms → facial muscles in severe cases.

Weakness is usually bilateral and roughly symmetrical.

Deep tendon reflexes reduced or absent early.

• Paresthesia (tingling) in feet and hands

• Mild sensory loss, but motor deficits more prominent

• Fluctuating BP

• Postural hypotension

• Arrhythmias

• Sweating abnormalities

• Urinary retention (sometimes)

• Facial weakness (bilateral facial palsy common)

• Difficulty swallowing (bulbar involvement)

May progress to respiratory failure – danger sign.

Muscle pain, radicular back pain, body aches common.

Unsteady gait due to weakness + sensory ataxia.

• Miller Fisher variant – ophthalmoplegia, ataxia, areflexia

• AMAN/AMSAN – more severe motor weakness, rapid decline

Weakness spreads to respiratory muscles → reduced vital capacity → need for ICU and mechanical ventilation.

Occurs in ~25% of hospitalized GBS patients.

• Wide BP fluctuations (labile hypertension/hypotension)

• Cardiac arrhythmias (bradycardia, tachycardia, heart block)

• Sweating abnormalities

• Urinary retention / overflow incontinence

Can be sudden and life-threatening.

• Neuropathic pain (burning, shooting)

• Deep aching pain in back and legs

Pain may precede weakness.

• Dysphagia

• Risk of aspiration pneumonia

• Facial weakness affecting airway protection

Immobilization → DVT and pulmonary embolism unless prophylaxis given.

• Pneumonia (due to poor cough/ventilation)

• UTI (due to urinary retention or catheter use)

• Ventilator-associated infections in intubated patients

Syndrome of inappropriate antidiuretic hormone secretion → hyponatremia.

Due to prolonged immobility.

Even after recovery, many patients have prolonged fatigue, distal weakness, or neuropathic symptoms.

AMAN/AMSAN variants may have slow or incomplete recovery due to axonal loss.

Anxiety, depression, insomnia from sudden paralysis and ICU stay.

GBS causes rapidly progressive ascending weakness; other acute neuromuscular disorders can mimic it.

Different GBS subtypes may resemble each other early and require electrophysiology for differentiation.

• Often has a sensory level

• Early bowel/bladder involvement

• UMN signs (hyperreflexia, spasticity) — NOT typical of GBS

• Back pain prominent

• Hyperreflexia, Babinski positive

• Emergency MRI needed if suspected

• Rapidly ascending flaccid paralysis

• Areflexia similar to GBS

• Improves dramatically after tick removal

• Descending paralysis (opposite of GBS)

• Pupillary dilation, blurred vision, dry mouth

• No sensory symptoms

• Fluctuating fatigable weakness

• Ocular, bulbar symptoms prominent

• Reflexes preserved

• Proximal weakness

• Hyporeflexia but improves after brief exercise

• Often associated with malignancy

• Abdominal pain + neuropathy

• Autonomic symptoms prominent

• History of pharyngeal illness

• Palatal paralysis early

• Slower progression than GBS

• Heavy metals

• Chemotherapy drugs

• Organophosphate poisoning

• May mimic GBS during acute seroconversion

• CSF pleocytosis more common

• Painful, asymmetric, multifocal

• Often mononeuritis multiplex

• Occurs in ICU patients

• Difficulty weaning from ventilator

• No classic ascending pattern

• Give-way weakness

• Preserved reflexes

• Inconsistent exam findings

GBS is most commonly triggered by an abnormal autoimmune response following an infection.

• Campylobacter jejuni — strongest association; lipooligosaccharides mimic gangliosides (GM1, GD1a).

• Cytomegalovirus (CMV).

• Epstein–Barr virus (EBV).

• Influenza virus.

• Mycoplasma pneumoniae.

• Zika virus.

• SARS-CoV-2 (COVID-19) — reported association in some outbreaks.

Historical links (e.g., 1976 influenza vaccine), but modern vaccines have extremely low risk; benefits outweigh risks.

Pathogen antigens resemble peripheral nerve gangliosides → immune system produces cross-reactive antibodies → complement activation → demyelination and/or axonal injury.

• Anti-GM1

• Anti-GD1a

• Anti-GT1a

• Anti-GQ1b (characteristic of Miller Fisher variant)

• AMSAN (Acute motor-sensory axonal neuropathy) — more severe axonal variant; often infection-related.

• Miller Fisher Syndrome (MFS) — linked to **anti-GQ1b antibodies**; ophthalmoplegia.

• Viral outbreaks (e.g., Zika-related surges)

• Older age increases severity

• Slight male predominance

GBS is generally sporadic; no familial pattern.

Nerve conduction study (NCS) shows demyelination: slowed conduction velocity, prolonged distal latencies, conduction block. Helps differentiate subtypes (AIDP vs AMAN/AMSAN).*

Blood tests (rule out mimics)

CBC, ESR/CRP, electrolytes, HbA1c, LFT/RFT, B12, thyroid profile to exclude metabolic or inflammatory neuropathies.

Infection workup when history suggests

Stool PCR/serology for Campylobacter jejuni, viral serology (CMV, EBV, HIV, Zika), respiratory PCR if recent illness.

Respiratory monitoring

Serial FVC, NIF (negative inspiratory force). Detects early respiratory compromise.

Autonomic monitoring

Continuous BP and ECG monitoring to detect arrhythmias, BP fluctuations.

MRI spine (if needed)

May show enhancement of spinal nerve roots, cauda equina. Used mainly to rule out spinal cord compression.

NCS patterns useful for subtype identification

AIDP → demyelinating features.

AMAN/AMSAN → reduced CMAP amplitudes with minimal demyelination.

MFS → normal limbs but absent H-reflex ± abnormal oculomotor nerves.

Characteristic demyelinating features (AIDP)

• Reduced CMAP amplitudes if secondary axonal loss begins

• Sensory nerve action potentials (SNAPs) often preserved early

• Absent H-reflexes in most patients

Axonal variants (AMAN / AMSAN)

• Normal conduction velocity and latency

• Severely reduced CMAP amplitudes early

• Normal sensory responses in AMAN

• Reduced SNAPs in AMSAN

• No conduction block (distinguishes from AIDP)

• F-waves often absent due to axonal involvement

Early changes (first few days)

• H-reflex absent before other abnormalities appear

• Mild slowing or normal NCS early → repeat after 7–14 days improves diagnostic clarity

Typical electrophysiologic pattern in AIDP

• Motor conduction velocity < 70% of lower limit

• Distal latency > 130% of upper limit

• CMAP amplitude > 20% drop on proximal stimulation → conduction block

Miller–Fisher Syndrome (MFS)

• Often normal motor conduction studies

• Reduced or absent sensory nerve action potentials

• Absent H-reflex is highly sensitive

• EMG usually normal

When to repeat NCS/EMG

• If initial test is normal but clinical suspicion is high

• Best diagnostic yield between 7–14 days from symptom onset

• Helps distinguish CIDP evolution from GBS if symptoms progress beyond 8 weeks

GBS is caused by an abnormal immune response that mistakenly targets components of the peripheral nervous system.

Antigens of preceding infections (e.g., C. jejuni, CMV, EBV, Zika, influenza, Mycoplasma) resemble gangliosides on peripheral nerves → antibodies cross-react → immune attack.

Cross-reactive antibodies bind to gangliosides on Schwann cells or axolemma → activate complement → membrane attack complex (MAC) formation → segmental demyelination and/or axonal damage.

Activated macrophages penetrate the basal lamina of Schwann cells → strip myelin in a patchy, segmental pattern → slowed or blocked nerve conduction.

Inflammation disrupts Na⁺ channel clusters → conduction failure → acute flaccid paralysis.

• **AIDP** – autoimmune T-cell & macrophage–mediated demyelination.

• **AMAN** – antibody-mediated attack on axolemma (GM1, GD1a) → pure motor axonal injury.

• **AMSAN** – similar to AMAN but sensory axons also affected.

• **Miller–Fisher Syndrome** – anti-GQ1b antibodies → affects cranial nerves → ophthalmoplegia.

Inflammation increases permeability, allowing immune cells & antibodies to reach nerve roots and peripheral nerves.

• Conduction block

• Slowed nerve conduction velocity

• Muscle weakness and areflexia

• Autonomic dysfunction in severe cases

GBS affects peripheral roots and nerves; the brain and spinal cord remain structurally normal.

Immune-mediated demyelination of peripheral nerves and nerve roots with secondary axonal damage.

Segmental demyelination, onion-bulb formations from Schwann-cell proliferation, macrophage-mediated myelin stripping.

IgG4 autoantibodies disrupt axo-glial junctions → detachment of paranodal loops → conduction block without inflammation.

Endoneurial and perivascular T-cell and macrophage infiltration in classic CIDP.

Present in classic CIDP, but absent in IgG4-mediated forms.

Seen in chronic disease due to repeated cycles of demyelination and remyelination.

Occurs late and determines long-term disability.

CIDP is autoimmune and idiopathic in most patients; no vaccine or direct preventive measure exists.

Early recognition of relapse, prompt treatment, and regular follow-up reduce long-term disability.

Monitor blood sugar with steroids, avoid infections during immunosuppressive therapy, screen before rituximab.

Good infection control, managing chronic diseases (diabetes, HIV, hepatitis), and avoiding neurotoxic drugs if possible.

Physiotherapy, gait training, orthotic support, fall-prevention, and muscle-strength preservation.

Patients with known autoantibody-positive paranodal CIDP require closer monitoring as relapses may be more sudden.

Teach early danger signs—new limb weakness, falls, breathing difficulty, loss of bladder/bowel control.

GBS is acute immune activation; CIDP involves ongoing or relapsing immune activity targeting myelin.

IgG4 does not activate complement → little inflammation → poor response to IVIG/steroids but good response to rituximab.

Large-fiber sensory demyelination causes proprioceptive loss → sensory ataxia.

Demyelination slows conduction across reflex arcs → hyporeflexia/areflexia even before strength loss is severe.

Delayed treatment → irreversible axonal loss → permanent disability.

Motor-predominant CIDP with wasting may resemble ALS but conduction studies reveal demyelination.

Autoimmune activity persists; maintenance therapy is often needed.

Albuminocytologic dissociation → breakdown of blood-nerve barrier increases protein leakage but no inflammation in CSF.

NCS and clinical criteria are usually sufficient; biopsy reserved for unclear or atypical presentations.

Symmetric sensorimotor weakness progressing over ≥8 weeks; good response to IVIG or steroids.

Slower onset version mimicking acute GBS but evolving chronically.

Mainly distal sensory loss; often associated with IgM anti-MAG antibodies.

Asymmetric involvement; affects individual nerves; may mimic mononeuritis multiplex.

Weakness > sensory symptoms; may resemble motor neuropathies.

Profound sensory ataxia with minimal weakness.

IgG4 antibodies against NF155, NF186, CNTN1, CASPR1; poor response to IVIG but respond to rituximab.

Pure sensory CIDP variant with normal nerve conduction but abnormal somatosensory evoked potentials.

Periods of relapse and partial recovery; requires maintenance therapy.

Slow continuous decline without clear relapse pattern.

Bilateral, relatively symmetric weakness—starting in legs → ascending pattern.

Deep tendon reflexes markedly reduced or absent in involved limbs.

Weakness usually begins distally in legs → spreads proximally → may involve arms, facial, bulbar, and respiratory muscles.

• Facial diplegia (bilateral facial weakness)

• Dysphagia

• Dysarthria

• Ophthalmoplegia (especially in Miller–Fisher variant)

• Decreased vibration sense

• Distal paresthesias

• Reduced proprioception in some cases

• Tachycardia or bradycardia

• Labile blood pressure

• Arrhythmias

• Urinary retention

• Ileus or constipation

Weak diaphragm + accessory muscles → ↓ vital capacity → impending respiratory failure.

Steppage gait due to foot drop; inability to walk independently in progressive stages.

Paraspinal or proximal limb tenderness (due to nerve root inflammation).

Sensory ataxia with preserved motor strength → unsteady gait.

It typically presents with rapidly progressive, symmetrical weakness beginning in the legs and ascending upward, often accompanied by sensory symptoms and areflexia.

GBS is classically a **post-infectious autoimmune disorder**, where the immune system mistakenly targets peripheral nerve myelin or axons through molecular mimicry.

Most patients develop symptoms **1–3 weeks after a preceding infection** such as Campylobacter jejuni, CMV, EBV, Mycoplasma, influenza, or other respiratory/GI pathogens.

The disease progresses for up to 4 weeks, followed by a plateau phase and gradual recovery.

Timely diagnosis and management are essential because **respiratory muscle involvement** can lead to respiratory failure requiring ventilatory support.

Although potentially life-threatening, **the majority of patients recover**, especially with early IVIG or plasmapheresis.

References

PDF

wiki

Dr Sankaran • 2025-11-27 23:48:47

Georges Charles Guillain

Dr Sankaran • 2025-11-27 23:48:24

Campylobacter jejuni

Dr Sankaran • 2025-11-27 23:46:56

Weakness typically begins in the legs → ascends upwards over days to weeks.

Tingling, numbness, “pins and needles” in feet and hands; often the earliest symptom.

Unsteady gait, frequent falls, inability to climb stairs or rise from sitting.

Deep aching pain in the lower back or thighs; common early sign.

• Facial weakness (bilateral facial palsy).

• Difficulty swallowing.

• Diplopia.

• Dysarthria.

Shortness of breath, weak cough, orthopnea — due to diaphragmatic weakness.

• Palpitations

• Postural dizziness

• Sweating abnormalities

• Urinary retention

• Constipation

Pain, paresthesias > objective sensory loss.

Symptoms worsen over 2–4 weeks (unlike CIDP which progresses >8 weeks).

• MFS – ophthalmoplegia, ataxia, areflexia.

• AMAN – pure motor weakness without sensory loss.

All suspected GBS patients must be monitored in a hospital (preferably ICU/HDU) due to risk of respiratory failure and autonomic instability.

Start immediately if:

• Unable to walk independently for ≥10 meters

• Rapid progression

• Significant bulbar or respiratory involvement

• Rapidly worsening autonomic instability

• Intravenous immunoglobulin (IVIG) 0.4 g/kg/day × 5 days

• Plasma exchange (PLEX) 4–6 exchanges over 7–10 days

Both are equally effective — **do NOT combine** (no added benefit).

• Hemodynamic instability

• Elderly or frail

• Easier administration

• Poor venous access

• Slightly better in children

• Very rapid progression

• High antibody burden (e.g., axonal variants)

• When IVIG contraindicated (renal failure, IgA deficiency)

• Serial vital capacity: intubate if VC < 15 mL/kg

• Watch for: weak cough, difficulty clearing secretions

• Early ICU transfer for impending failure

• Treat arrhythmias, BP swings, urinary retention

• Avoid drugs causing bradycardia or hypotension

• Cardiac monitoring in moderate–severe cases

• Neuropathic pain common

• Use: gabapentin, pregabalin, carbamazepine, tramadol

• Avoid heavy opioids if possible

• Enoxaparin or mechanical prophylaxis due to immobility

• Physiotherapy as soon as medically safe

• Prevent contractures and pressure ulcers

• Speech therapy for bulbar involvement

• Early nutritional support (NG/PEG if needed)

• Do NOT give corticosteroids (ineffective in GBS)

• Do NOT combine IVIG + PLEX

• Do NOT delay treatment waiting for EMG/LP reports

• FVC every 4–6 hours in early phase

• Continuous cardiac monitoring

• Pain and autonomic symptoms daily

• Electrophysiology if diagnosis uncertain

• Majority improve within weeks

• Recovery may take months

• Axonal forms (AMAN/AMSAN) have slower recovery

• 8–10% worsen again after initial improvement

• May require repeat IVIG course or PLEX

• Strength recovery exercises

• Occupational therapy

• Assistive devices for walking

• Psychological support due to prolonged recovery period