Guillain-Barré Syndrome — AMAN (acute motor axonal)
Encounter flow
12/12 authoredCanonical 12-phase frame with authored status for this dossier.
Frame
Confirm AMAN — pure motor ascending areflexic weakness + preceding Campylobacter + axonal NCS pattern (Brighton 2011 PMID 24163275; van Doorn 2011 PMID 25023340)
AMAN-compatible pattern; cord compression excluded
Patient inputs (13)
Anti-GM1 / GD1a in ~60-80% AMAN; supports diagnosis (Yuki 2007 PMID 22694000)
Reduced CMAP without slowing + preserved sensory NCS confirms AMAN (van Doorn 2011 PMID 25023340)
Age + geographic/ethnic context informs AMAN likelihood (van Doorn 2011 PMID 25023340)
Campylobacter gastroenteritis 1-3 wk prior strong AMAN risk factor (Yuki 2007 PMID 22694000)
Pure motor pattern (preserved sensation) pivots AMAN from AIDP (van Doorn 2011)
Albumino-cytologic dissociation — present in ~50% wk 1, 75% wk 2 (AAN 2012)
IgA deficiency screen before IVIG (anaphylaxis risk) (EAN/PNS 2023)
Exclude transverse myelitis / cord compression (NICE 2024)
20-30-40 rule — FVC <20 mL/kg or NIF magnitude <30 cmH2O triggers elective intubation (AAN 2012)
Autonomic — paroxysmal tachy/brady (IGOS Doets 2018)
Autonomic BP swings (IGOS Doets 2018)
MRC sum 0-60 quantifies severity + tracks progression (AAN 2012)
Stool Campylobacter culture / PCR — confirms preceding infection (Yuki 2007)
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Severity triggers (7)
- informationallife_threateningrapidly_progressive_quadriparesisAMAN often more rapid than AIDP — quadriparesis within 24-48 h; high EGRIS risk → immediate ICU (IGOS Doets 2018 PMID 30247567; Walgaard 2009 PMID 20517939)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalseverepure_motor_axonal_NCSAMAN signature: reduced CMAP without slowing + preserved sensory NCS = pure motor axonal pattern; pivots away from AIDP demyelinating (van Doorn 2011 PMID 25023340)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalseverepost_campylobacterPreceding Campylobacter jejuni gastroenteritis 1-3 wk prior — strong AMAN risk; molecular mimicry between LOS and GM1/GD1a gangliosides (Yuki 2007 PMID 22694000)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereanti-GM1_GD1a_positiveAnti-GM1 and/or anti-GD1a antibodies positive — supports AMAN diagnosis (~60-80% positivity in AMAN) (Yuki 2007 PMID 22694000)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalseverepediatric_aman_highPediatric AMAN — high prevalence in Asian children especially during Campylobacter outbreaks (van Doorn 2011 PMID 25023340)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalmoderateslower_recovery_axonalAMAN slower long-term recovery than AIDP due to axonal regeneration time (~1 mm/day); extended rehab + IRF preferred over SNF (Walgaard 2011 PMID 21403108)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalmoderatepreserved_sensation_pivotAMAN signature: PRESERVED sensation despite areflexic ascending weakness — key clinical pivot from AIDP glove-and-stocking (van Doorn 2011 PMID 25023340)Trigger could not be auto-evaluated — needs clinician judgement.
Workflow calculators
Run this disease's risk and dosing calculators inline.
Recommended regimen
AMAN — IVIG/PLEX (same dose as AIDP) + extended rehab planning (Hughes Cochrane 2014 PMID 25238327; van Doorn 2011)- ivigfirst linepooled_human_IgG0.4 g/kg/d × 5 d (total 2 g/kg) • IV • daily × 5 d (max: 2 g/kg cumulative)triggers: aman_brighton_1_3, non_ambulatory_or_progressiveHughes Cochrane 2014 PMID 25238327 — IVIG and PLEX equivalent in AMAN; check IgA pre-IVIG (EAN/PNS 2023)rxcui 1426680
- plasmapheresis (PLEX)first lineapheresis5 sessions over 7-10 d (q48h) • IV • 5 sessions q48htriggers: iga_deficient, ivig_unavailable, rapidly_progressiveRaphael Cochrane PMID 22786475 — equivalent; do NOT combine
outpatient playbook — drug actions (1)
- 1. gabapentin / pregabalin taperPer pain response • PO • tapertrigger: Pain resolvingNICE 2024
Auto-drafted A&P note
outpatientSubjective
- Possible entry pathways: Pure motor ascending symmetric weakness with PRESERVED sensation; areflexia (van Doorn 2011 PMID 25023340); Preceding Campylobacter jejuni gastroenteritis (diarrhea) 1-3 wk prior — strong AMAN association (Yuki 2007 PMID 22694000); NCS pure motor axonal pattern: reduced CMAP amplitudes WITHOUT slowing; preserved sensory NCS (van Doorn 2011 PMID 25023340).
Objective
- No vitals, labs, or imaging entered for this encounter.
Assessment
**Guillain-Barré Syndrome — AMAN (acute motor axonal)** (neuro.gbs-aman.v1). Phenotype framing: AMAN (this engine) vs AIDP (route gbs-aidp; demyelinating + sensory) vs MFS (route gbs-miller-fisher) vs AMSAN (encoded in parent severity) vs botulism vs tick paralysis (van Doorn 2011) Scope: Confirm AMAN — pure motor ascending areflexic weakness + preceding Campylobacter + axonal NCS pattern (Brighton 2011 PMID 24163275; van Doorn 2011 PMID 25023340) No severity triggers fired against current inputs.
Plan
Regimen axis: **AMAN — IVIG/PLEX (same dose as AIDP) + extended rehab planning (Hughes Cochrane 2014 PMID 25238327; van Doorn 2011)** — step "Step 1 — Acute immunomodulation (within 2-4 wk of onset)". 1. ivig 0.4 g/kg/d × 5 d (total 2 g/kg) IV daily × 5 d (pooled_human_IgG, first line) — Hughes Cochrane 2014 PMID 25238327 — IVIG and PLEX equivalent in AMAN; check IgA pre-IVIG (EAN/PNS 2023) 2. plasmapheresis (PLEX) 5 sessions over 7-10 d (q48h) IV 5 sessions q48h (apheresis, first line) — Raphael Cochrane PMID 22786475 — equivalent; do NOT combine Setting playbook (outpatient) — Post-acute AMAN — extended rehab (axonal loss → slower recovery); residual disability monitoring; CIDP surveillance; vaccine-delay advice (van Doorn 2011 PMID 25023340) 3. gabapentin / pregabalin taper Per pain response PO taper — Pain resolving (NICE 2024) Non-pharmacologic actions: - Continued PT/OT — likely longer course than AIDP (NICE 2024) - Vaccine timing discussion with neurology (NICE 2024) - Driving + return-to-work assessment (NICE 2024) AVOID / contraindication checks: - No_steroids_alone_for_GBS_AMAN (Hughes Cochrane 2014) - Check_IgA_before_IVIG (EAN/PNS 2023) - Avoid_succinylcholine_use_rocuronium_with_sugammadex (AAN 2012) - DVT_prophylaxis_high_immobility_risk (EAN/PNS 2023) - Do_not_combine_IVIG_and_PLEX (Hughes Cochrane 2014) - Extended_rehab_for_AMAN_axonal_loss (van Doorn 2011)
Monitoring
Regimen monitoring: - FVC NIF q4-6h during progression (AAN 2012) - continuous ECG for autonomic arrhythmias (IGOS Doets 2018) - BP q1-2h during unstable phase (IGOS Doets 2018) - MRC sum score daily (AAN 2012) - IVIG AE TRALI aseptic meningitis thrombosis (EAN/PNS 2023) - extended rehab trajectory AMAN (Walgaard 2011 PMID 21403108) Setting (outpatient) monitoring: - Functional recovery at 6 wk, 3 mo, 6 mo, 1 yr, 2 yr (NICE 2024) - CIDP red-flag watch (van Doorn 2011) Follow-up plan: Neuro rehab (often longer than AIDP due to axonal loss), CIDP surveillance, psychology (NICE 2024) - Close-out criterion: Extended rehab + neurology follow-up scheduled Monitoring phase: q4-6h FVC/NIF, continuous ECG, MRC + disability score; AMAN has slower recovery — extended rehab planning (Walgaard 2011 PMID 21403108)
Disposition
Current setting: outpatient — Post-acute AMAN — extended rehab (axonal loss → slower recovery); residual disability monitoring; CIDP surveillance; vaccine-delay advice (van Doorn 2011 PMID 25023340) Disposition criteria: - Routine follow-up; annual neuromuscular review with extended baseline (NICE 2024) Escalation triggers (move to higher acuity): - Worsening / new weakness >8 wk → CIDP workup (van Doorn 2011)
Earlier-Return Triggers
Return-precaution thresholds (watch for): - [LIFE_THREATENING] AMAN often more rapid than AIDP — quadriparesis within 24-48 h; high EGRIS risk → immediate ICU (IGOS Doets 2018 PMID 30247567; Walgaard 2009 PMID 20517939) - [SEVERE] AMAN signature: reduced CMAP without slowing + preserved sensory NCS = pure motor axonal pattern; pivots away from AIDP demyelinating (van Doorn 2011 PMID 25023340) - [SEVERE] Preceding Campylobacter jejuni gastroenteritis 1-3 wk prior — strong AMAN risk; molecular mimicry between LOS and GM1/GD1a gangliosides (Yuki 2007 PMID 22694000)
Citations
- 2023 EAN/PNS GBS Guideline + Hughes Cochrane 2014 + Yuki 2007 (Campylobacter molecular mimicry) [PMID:25238327](https://pubmed.ncbi.nlm.nih.gov/25238327/) - Cited evidence (PMID 22786475) [PMID:22786475](https://pubmed.ncbi.nlm.nih.gov/22786475/) - Cited evidence (PMID 25023340) [PMID:25023340](https://pubmed.ncbi.nlm.nih.gov/25023340/) - Cited evidence (PMID 24163275) [PMID:24163275](https://pubmed.ncbi.nlm.nih.gov/24163275/) - Cited evidence (PMID 20517939) [PMID:20517939](https://pubmed.ncbi.nlm.nih.gov/20517939/) Last reconciled with current guidelines: 2026-05-22.
- 2023 EAN/PNS GBS Guideline + Hughes Cochrane 2014 + Yuki 2007 (Campylobacter molecular mimicry) — PMID:25238327
- Cited evidence (PMID 22786475) — PMID:22786475
- Cited evidence (PMID 25023340) — PMID:25023340
- Cited evidence (PMID 24163275) — PMID:24163275
- Cited evidence (PMID 20517939) — PMID:20517939