Myasthenia Gravis - New Diagnosis

VERSION: 1.0 CREATED: January 27, 2026 REVISED: January 27, 2026 STATUS: Initial creation

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DIAGNOSIS: Myasthenia Gravis - New Diagnosis

ICD-10: G70.0 (Myasthenia gravis), G70.00 (MG without exacerbation), G70.01 (MG with exacerbation)

CPT CODES: 85025 (CBC with differential), 80053 (CMP), 84443 (TSH), 84439 (Free T4), 85652 (ESR), 86140 (CRP), 86235 (AChR binding antibody), 82947 (Blood glucose), 83036 (HbA1c), 81003 (Urinalysis), 83735 (Magnesium), 84100 (Phosphorus), 85610 (PT/INR), 80074 (Hepatitis B surface antigen), 82306 (Vitamin D (25-OH)), 87389 (HIV), 86334 (SPEP with immunofixation), 71260 (CT chest with contrast), 71046 (Chest X-ray (PA and lateral)), 95937 (Repetitive nerve stimulation (RNS)), 95872 (Single-fiber EMG (SFEMG)), 96365 (Methylprednisolone IV (pulse therapy)), 36514 (Plasmapheresis (PLEX) - rescue)

SYNONYMS: Myasthenia gravis, MG, new MG diagnosis, ocular myasthenia, generalized myasthenia, anti-AChR MG, anti-MuSK MG, seronegative MG, autoimmune neuromuscular junction disorder, fatigable weakness

SCOPE: Initial diagnostic workup and management of suspected or newly confirmed myasthenia gravis. Covers antibody testing, electrodiagnostic studies, thymoma screening, acute stabilization, and long-term immunotherapy initiation. For myasthenic crisis with respiratory failure, use "Myasthenic Crisis" template. For established MG on maintenance therapy, use "MG - Maintenance" template.

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PRIORITY KEY: STAT = Immediate | URGENT = Within hours | ROUTINE = Standard | EXT = Extended/atypical cases | - = Not applicable to this setting

═══════════════════════════════════════════════════════════ SECTION A: ACTION ITEMS ═══════════════════════════════════════════════════════════

1. LABORATORY WORKUP

1A. Essential/Core Labs

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
CBC with differential (CPT 85025)	STAT	STAT	ROUTINE	STAT	Baseline before immunotherapy; infection screen	Normal
CMP (CPT 80053)	STAT	STAT	ROUTINE	STAT	Renal/hepatic function baseline; electrolytes	Normal
TSH (CPT 84443)	URGENT	ROUTINE	ROUTINE	URGENT	Thyroid disease co-occurs in 10-15% of MG; autoimmune overlap	Normal
Free T4 (CPT 84439)	URGENT	ROUTINE	ROUTINE	URGENT	Thyroid function; Graves disease association	Normal
ESR (CPT 85652)	URGENT	ROUTINE	ROUTINE	URGENT	Inflammatory/autoimmune screen	Normal (<20 mm/hr)
CRP (CPT 86140)	URGENT	ROUTINE	ROUTINE	URGENT	Inflammatory marker; infection screen	Normal
AChR binding antibody (CPT 86235)	URGENT	URGENT	ROUTINE	URGENT	Primary diagnostic test; positive in ~85% generalized MG, ~50% ocular MG	Negative (<0.02 nmol/L)
AChR blocking antibody (CPT 86235)	URGENT	URGENT	ROUTINE	URGENT	Complements binding antibody; increases sensitivity	Negative
AChR modulating antibody (CPT 86235)	URGENT	URGENT	ROUTINE	URGENT	Complements binding/blocking; increases sensitivity to ~95% in generalized MG	Negative
Blood glucose (CPT 82947)	STAT	STAT	ROUTINE	STAT	Pre-steroid baseline	Normal
HbA1c (CPT 83036)	-	ROUTINE	ROUTINE	-	Glycemic status before corticosteroid initiation	<5.7%
Urinalysis (CPT 81003)	STAT	STAT	ROUTINE	STAT	Infection screen; baseline	Negative
LDH	-	ROUTINE	ROUTINE	-	Baseline; monitor for hemolysis on complement inhibitors	Normal
Magnesium (CPT 83735)	STAT	STAT	ROUTINE	STAT	Hypomagnesemia worsens NMJ transmission	Normal (1.7-2.2 mg/dL)
Phosphorus (CPT 84100)	STAT	STAT	ROUTINE	STAT	Baseline electrolyte panel	Normal
PT/INR (CPT 85610)	STAT	STAT	-	STAT	Coagulation baseline before procedures	Normal
Hepatitis B surface antigen (CPT 80074)	-	ROUTINE	ROUTINE	-	Screen before rituximab/immunosuppression (reactivation risk)	Negative

1B. Extended Workup (Second-line)

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
MuSK antibody (anti-MuSK IgG) (CPT 86235)	URGENT	URGENT	ROUTINE	URGENT	Positive in ~40% of AChR-seronegative MG; distinct phenotype (bulbar, facial, neck weakness)	Negative
LRP4 antibody	-	ROUTINE	ROUTINE	-	Positive in ~2-50% of double-seronegative MG; newer assay	Negative
Anti-striated muscle antibody (anti-SM)	-	ROUTINE	ROUTINE	-	Associated with thymoma in MG patients <40 years; screening marker	Negative
Anti-titin antibody	-	ROUTINE	ROUTINE	-	Associated with thymoma (especially in young-onset MG); late-onset MG marker	Negative
Anti-RyR (ryanodine receptor) antibody	-	ROUTINE	ROUTINE	-	Associated with thymoma and severe MG	Negative
ANA (CPT 86235)	-	ROUTINE	ROUTINE	-	Autoimmune overlap screen (SLE, Sjogren)	Negative or low titer
Anti-TPO antibody	-	ROUTINE	ROUTINE	-	Autoimmune thyroiditis co-occurrence (Hashimoto/Graves)	Negative
Vitamin D (25-OH) (CPT 82306)	-	ROUTINE	ROUTINE	-	Immune modulation; deficiency common	>30 ng/mL
Hepatitis B core antibody	-	ROUTINE	ROUTINE	-	Screen for prior HBV before rituximab	Negative
Hepatitis C antibody (CPT 80074)	-	ROUTINE	ROUTINE	-	Screen before immunosuppression	Negative
HIV (CPT 87389)	-	ROUTINE	ROUTINE	-	Screen before immunosuppression	Negative
Quantitative immunoglobulins (IgG, IgA, IgM)	-	ROUTINE	ROUTINE	-	Baseline before IVIG; monitor on rituximab/immunosuppression	Normal
SPEP with immunofixation (CPT 86334)	-	ROUTINE	EXT	-	Paraproteinemic neuropathy/NMJ screen in atypical cases	Normal
Complement C3, C4	-	ROUTINE	ROUTINE	-	Baseline before complement inhibitor therapy	Normal
Reticulocyte count	-	ROUTINE	ROUTINE	-	Baseline before complement inhibitors (hemolysis monitoring)	Normal
Haptoglobin	-	ROUTINE	ROUTINE	-	Baseline for hemolysis monitoring on complement inhibitors	Normal
TB test (QuantiFERON-Gold or PPD)	-	ROUTINE	ROUTINE	-	Screen before immunosuppression	Negative

1C. Rare/Specialized (Refractory or Atypical)

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
Agrin antibody	-	EXT	EXT	-	Novel antibody target in seronegative MG	Negative
Cortactin antibody	-	EXT	EXT	-	Identified in some seronegative MG	Negative
ColQ antibody	-	EXT	EXT	-	Congenital myasthenic syndrome screen	Negative
Genetic testing (CMS gene panel)	-	-	EXT	-	Congenital myasthenic syndromes (CHRNE, DOK7, RAPSN, etc.) if onset <2 years or seronegative/atypical	Depends on gene
Paraneoplastic antibody panel (ANNA-1, VGCC, GAD65)	-	EXT	EXT	-	LEMS or overlap paraneoplastic syndrome	Negative
VGCC antibody (P/Q-type)	-	EXT	EXT	-	Lambert-Eaton myasthenic syndrome screen	Negative (<0.02 nmol/L)
SOX1 antibody	-	EXT	EXT	-	Associated with SCLC in LEMS	Negative
Acetylcholine receptor ganglionic antibody	-	EXT	EXT	-	Autonomic neuropathy overlap	Negative
Muscle biopsy	-	EXT	EXT	-	Myopathy screen if diagnosis unclear	Normal NMJ architecture
Anti-Kv1.4 antibody	-	EXT	EXT	-	Associated with myocarditis and severe MG phenotype (Japan)	Negative
CT-guided thymoma biopsy	-	EXT	EXT	-	If anterior mediastinal mass is atypical; tissue diagnosis	Depends on pathology

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2. DIAGNOSTIC IMAGING & STUDIES

2A. Essential/First-line

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
CT chest with contrast (CPT 71260)	URGENT	URGENT	ROUTINE	URGENT	Within 24-48h of diagnosis	No thymoma or thymic hyperplasia	Contrast allergy, renal insufficiency
MRI chest with contrast (preferred over CT if available)	-	ROUTINE	ROUTINE	-	Within 1-2 weeks	No thymoma; thymic hyperplasia characterization	Gadolinium allergy, GFR <30, pacemaker
Chest X-ray (PA and lateral) (CPT 71046)	STAT	STAT	ROUTINE	STAT	Immediate	No mediastinal mass; baseline pulmonary status	None significant
Portable chest X-ray (CPT 71046)	STAT	-	-	STAT	If unable to go to radiology	Pulmonary status; mediastinal widening	None significant

2B. Electrodiagnostic & Specialized Studies

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
Repetitive nerve stimulation (RNS) (CPT 95937)	-	URGENT	ROUTINE	-	During workup; stop pyridostigmine 12h prior if possible	Decremental response >10% at 2-3 Hz in proximal and distal muscles	Pacemaker (relative); recent botulinum toxin
Single-fiber EMG (SFEMG) (CPT 95872)	-	ROUTINE	ROUTINE	-	If RNS negative but clinical suspicion remains; most sensitive test (95-99%)	Increased jitter and blocking	Same as RNS; requires experienced electromyographer
Standard EMG/NCS (CPT 95886, 95907-95913)	-	ROUTINE	ROUTINE	-	If diagnosis unclear; rule out neuropathy/myopathy	Normal (unless concurrent condition)	None significant
Ice pack test (ocular MG)	URGENT	URGENT	ROUTINE	-	At bedside; apply ice to closed eyelid for 2 minutes	Improvement of ptosis by ≥2 mm (sensitivity ~80% for ocular MG)	Patient intolerance
Rest test (ocular MG)	URGENT	URGENT	ROUTINE	-	At bedside; rest with eyes closed for 2-5 minutes	Improvement of ptosis or diplopia	None
Sleep test (ocular MG)	-	ROUTINE	ROUTINE	-	At bedside; 30-minute nap then reassess	Improvement of ptosis/diplopia after rest	None

2C. Bedside Clinical Tests

Test	ED	HOSP	OPD	ICU	Timing	Target Finding	Notes
Sustained upgaze (2 minutes)	STAT	STAT	ROUTINE	STAT	Initial exam	No fatigable ptosis	Positive = ptosis develops or worsens with sustained upgaze
Repeated deltoid abduction (15-20 reps)	STAT	STAT	ROUTINE	STAT	Initial exam	No fatigable weakness	Positive = progressive weakness with repetitive testing
Cogan lid twitch sign	STAT	STAT	ROUTINE	STAT	Initial exam	No lid twitch	Have patient look down 15 sec, then look up: positive = brief upward overshoot of lid
Curtain sign (orbicularis oculi)	STAT	STAT	ROUTINE	STAT	Initial exam	No contralateral lid opening	While examiner holds one ptotic lid open, the other droops further
Peek sign	STAT	STAT	ROUTINE	STAT	Initial exam	Sustained eye closure	Patient gently closes eyes for 30 sec: positive = sclera becomes visible (orbicularis weakness)
Forced vital capacity (FVC)	STAT	STAT	-	STAT	At presentation and serially	>20 mL/kg (>1.5 L)	Critical: <15 mL/kg or <1 L = impending respiratory failure
Negative inspiratory force (NIF/MIP)	STAT	STAT	-	STAT	At presentation and serially	More negative than -40 cm H2O	Critical: weaker than -20 cm H2O = consider intubation

Note: Edrophonium (Tensilon) test rarely performed due to cardiac risks and availability issues; ice pack test preferred as bedside diagnostic.

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3. TREATMENT

3A. Cholinesterase Inhibitors (Symptomatic)

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Pyridostigmine (Mestinon) IR	-	-	30 mg :: - :: TID :: Start 30 mg TID; increase by 30 mg per dose every 2-3 days; usual effective dose 60 mg q4-6h while awake; max 120 mg per dose (max ~960 mg/day, rarely needed)	Mechanical GI/GU obstruction; uncontrolled asthma	Cholinergic side effects: diarrhea, cramping, salivation, bradycardia; cholinergic crisis if overdosed (weakness + muscarinic symptoms)	URGENT	URGENT	ROUTINE	URGENT
Pyridostigmine (Mestinon) SR (Timespan)	-	-	180 mg :: - :: qHS :: 180 mg qHS (sustained release); may give once or twice daily; do NOT crush	Same as IR	Same; useful for nocturnal/morning weakness; erratic absorption - use sparingly	-	ROUTINE	ROUTINE	-
Pyridostigmine liquid (60 mg/5 mL)	-	-	N/A :: - :: per protocol :: Same dosing as IR; useful for patients with dysphagia	Same as IR	Same; easier to swallow	URGENT	URGENT	ROUTINE	URGENT
Neostigmine IV (if NPO or intubated)	IV	-	0.5-2.5 mg :: IV :: - :: 0.5-2.5 mg IV/IM q1-3h; 1 mg IV neostigmine ≈ 30 mg oral pyridostigmine	Same; cardiac monitoring required	Continuous cardiac monitoring; have atropine at bedside for bradycardia	-	URGENT	-	URGENT
Glycopyrrolate (for cholinergic side effects)	IV	-	1-2 mg :: IV :: BID :: 1-2 mg PO BID-TID or 0.1-0.2 mg IV PRN	Narrow-angle glaucoma; obstructive uropathy	Does NOT cross BBB (preferred over atropine for peripheral muscarinic side effects)	-	ROUTINE	ROUTINE	-
Atropine (for cholinergic side effects/emergency)	IV	-	0.5-1 mg :: IV :: PRN :: 0.5-1 mg IV PRN for symptomatic bradycardia from pyridostigmine	Tachycardia; thyrotoxicosis	HR monitoring; crosses BBB (may cause confusion)	STAT	STAT	-	STAT
Pyridostigmine dose reduction/hold	-	-	N/A :: - :: per protocol :: Hold or reduce if cholinergic crisis suspected (worsening weakness + excessive secretions)	N/A	Distinguish cholinergic crisis (excess pyridostigmine) from myasthenic crisis (undertreated MG)	-	URGENT	ROUTINE	URGENT

Note: MuSK-positive MG often responds poorly to pyridostigmine and may worsen; use cautiously and consider early immunotherapy.

3B. Corticosteroids (Immunosuppression - Induction)

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Prednisone (gradual escalation - PREFERRED for outpatient)	PO	-	10-20 mg :: PO :: daily :: Start 10-20 mg daily; increase by 5-10 mg every 3-5 days to target 0.5-1 mg/kg/day (typically 40-60 mg daily); maintain 4-8 weeks then taper by 5-10 mg/month	Active untreated infection; uncontrolled diabetes; psychosis history	Glucose (q6h inpatient, weekly outpatient); BP; mood/sleep; weight; bone density at baseline; GI prophylaxis	-	ROUTINE	ROUTINE	-
Prednisone (rapid escalation - INPATIENT preferred)	PO	-	40-60 mg :: PO :: daily :: Start 40-60 mg daily (0.75-1 mg/kg/day); CAUTION: may cause initial transient worsening in first 1-2 weeks	Same as above	Same; MONITOR CLOSELY for steroid-induced exacerbation; consider concurrent IVIG/PLEX for protection	-	URGENT	-	URGENT
Methylprednisolone IV (pulse therapy) (CPT 96365)	IV	-	1000 mg :: IV :: daily :: 1000 mg IV daily × 3-5 days; transition to oral prednisone taper	Active untreated infection; uncontrolled diabetes; psychosis	Glucose q6h (target <180); BP; mood; cardiac monitoring; GI prophylaxis	STAT	STAT	-	STAT
Omeprazole (GI prophylaxis during steroids)	PO	-	20-40 mg :: PO :: daily :: 20-40 mg daily while on steroids	PPI allergy	None routine	STAT	STAT	ROUTINE	STAT
Insulin sliding scale (steroid-induced hyperglycemia)	-	-	180 mg :: - :: - :: Per protocol if glucose >180 mg/dL	Hypoglycemia risk	Glucose q6h	STAT	STAT	-	STAT
Calcium carbonate + Vitamin D (bone protection)	-	-	1000-1200 mg :: PO :: daily :: Calcium 1000-1200 mg + Vitamin D 1000-2000 IU daily while on chronic steroids	Hypercalcemia; hyperparathyroidism	Serum calcium; consider DEXA if anticipated steroid course >3 months	-	ROUTINE	ROUTINE	-
Bisphosphonate (bone protection if chronic steroids)	PO	-	70 mg :: PO :: - :: Alendronate 70 mg PO weekly OR risedronate 35 mg PO weekly; start if steroids expected >3 months	GFR <35; esophageal disorders; inability to remain upright 30 min	DEXA at baseline; renal function; dental exam (ONJ risk)	-	-	ROUTINE	-
Trimethoprim-sulfamethoxazole (PCP prophylaxis)	PO	-	800 mg :: PO :: daily :: 1 DS tablet (160/800 mg) daily or 3 times per week if prednisone ≥20 mg for ≥4 weeks	Sulfonamide allergy; severe renal impairment	CBC; renal function; use dapsone or atovaquone if allergic	-	ROUTINE	ROUTINE	-
Prednisone taper	-	-	5-10 mg :: - :: Once :: Once stable on target dose for 4-8 weeks: decrease by 5-10 mg every 2-4 weeks until 20 mg, then decrease by 2.5-5 mg monthly; target lowest effective dose or off	Do NOT stop abruptly if >2 weeks of therapy	Adrenal insufficiency symptoms; disease flare; cortisol level if concerns	-	ROUTINE	ROUTINE	-

Note: Steroid-induced transient worsening occurs in ~50% of patients within first 2 weeks of high-dose initiation. Consider starting steroids in-hospital for patients with moderate-severe generalized MG or bulbar symptoms, or provide "bridge" therapy with IVIG/PLEX.

3C. Steroid-Sparing Immunosuppressive Agents

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Mycophenolate mofetil (CellCept)	-	-	500 mg :: PO :: BID :: Start 500 mg BID; increase to 1000 mg BID after 2 weeks; target 2000-3000 mg/day in divided doses; onset 6-12 months	Pregnancy (Category D - teratogenic); concurrent azathioprine	CBC q2 weeks × 3 months, then monthly; LFTs; GI side effects (diarrhea, nausea); lymphopenia; REMS pregnancy prevention	-	ROUTINE	ROUTINE	-
Azathioprine (Imuran)	PO	-	50 mg :: PO :: daily :: Start 50 mg daily; increase by 50 mg every 1-2 weeks to target 2-3 mg/kg/day (typically 150-250 mg/day); onset 6-18 months	TPMT deficiency (check before starting); concurrent allopurinol (reduce dose by 75%); pregnancy (relative)	TPMT genotype/activity BEFORE starting; CBC q1-2 weeks during titration, then monthly; LFTs; amylase/lipase if abdominal pain; lymphocyte count target 600-1000	-	ROUTINE	ROUTINE	-
Tacrolimus (Prograf)	PO	-	1 mg :: PO :: BID :: Start 1 mg BID; titrate to trough level 5-10 ng/mL; onset 3-6 months (faster than MMF/AZA)	Uncontrolled hypertension; renal impairment	Trough levels; renal function q2 weeks then monthly; electrolytes (K, Mg); glucose; BP; tremor; nephrotoxicity	-	-	ROUTINE	-
Cyclosporine (Sandimmune/Neoral)	PO	-	2-3 mg/kg :: PO :: - :: Start 2-3 mg/kg/day in 2 divided doses; target trough 100-150 ng/mL; onset 2-6 months	Uncontrolled hypertension; renal impairment; concurrent nephrotoxic drugs	Trough levels; renal function; BP; electrolytes (K, Mg); lipids; gingival hyperplasia; hirsutism	-	-	ROUTINE	-
Methotrexate	SC	-	10-20 mg :: SC :: daily :: 10-20 mg PO or SC once weekly with folic acid 1 mg daily (except methotrexate day); onset 6-12 months	Pregnancy (Category X); hepatic disease; renal impairment (CrCl <30); concurrent trimethoprim	CBC q4 weeks; LFTs q8-12 weeks; renal function; pulmonary toxicity screen; folic acid supplementation mandatory	-	-	EXT	-
Cyclophosphamide (refractory/severe)	IV	-	500-1000 mg :: IV :: monthly :: Pulse IV: 500-1000 mg/m² monthly × 6 months; OR oral 1-2 mg/kg/day; reserved for refractory MG	Pregnancy; active infection; bone marrow suppression	CBC weekly during treatment; urinalysis (hemorrhagic cystitis - MESNA with IV dosing); fertility counseling; malignancy risk	-	EXT	EXT	EXT
IVIG (maintenance immunomodulation)	PO	-	1-2 g/kg :: PO :: - :: 1-2 g/kg divided over 2-5 days, then 0.4-1 g/kg every 4 weeks as maintenance	IgA deficiency (check IgA level first); recent thrombotic event; renal failure	Pre-infusion: IgA level, renal function, CBC; during: vital signs q15 min first hour; headache; aseptic meningitis; thrombosis risk; renal function	-	ROUTINE	ROUTINE	ROUTINE

3D. Biologics, Complement Inhibitors & Rescue Therapies

Treatment	Route	Indication	Dosing	Pre-Treatment Requirements	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Rituximab (Rituxan) (CPT 96365)	IV	-	375 mg :: IV :: - :: 375 mg/m² IV weekly × 4 weeks; OR 1000 mg IV × 2 doses 14 days apart; re-dose when CD19/CD20 recover or clinical worsening; onset 3-6 months	-	Active Hepatitis B; active infection; severe immunodeficiency	HBV serology before; CD19/CD20 counts q3-6 months; immunoglobulins q6 months; PML risk (very rare); infusion reactions (premedicate with acetaminophen, diphenhydramine, methylprednisolone)	-	ROUTINE	ROUTINE	-
Eculizumab (Soliris) (CPT 96365)	IV	-	900 mg :: IV :: - :: 900 mg IV weekly × 4 weeks, then 1200 mg IV at week 5, then 1200 mg IV every 2 weeks; for AChR-positive generalized MG	-	Unresolved Neisseria meningitidis infection; unvaccinated against meningococcus	Meningococcal vaccine ≥2 weeks before; REMS program; CBC; LDH/reticulocyte (hemolysis on discontinuation); signs of meningococcal infection; ciprofloxacin prophylaxis recommended	-	ROUTINE	ROUTINE	-
Ravulizumab (Ultomiris)	IV	-	N/A :: IV :: q8wk :: Weight-based loading dose IV, then maintenance every 8 weeks; for AChR-positive generalized MG	-	Same as eculizumab	Same as eculizumab; less frequent dosing advantage	-	ROUTINE	ROUTINE	-
Zilucoplan (Zilbrysq)	SC	-	0.3 mg/kg :: SC :: daily :: 0.3 mg/kg SC daily (self-administered); for AChR-positive generalized MG	-	Same as eculizumab	Same meningococcal vaccination required; injection site reactions; LDH; reticulocyte count	-	-	ROUTINE	-
Efgartigimod (Vyvgart) (CPT 96365)	IV	-	10 mg/kg :: IV :: - :: 10 mg/kg IV weekly × 4 weeks per cycle; may repeat based on clinical response; for AChR-positive generalized MG	-	Active infection; concurrent IgG-dependent therapies	IgG levels (expect ~70% reduction); infection monitoring; no meningococcal vaccine required	-	ROUTINE	ROUTINE	-
Efgartigimod/hyaluronidase SC (Vyvgart Hytrulo)	SC	-	1008 mg :: SC :: - :: 1008 mg efgartigimod + 11,200 units hyaluronidase SC weekly × 4 weeks per cycle	-	Same as IV efgartigimod	Same; injection site reactions; self-administered option	-	-	ROUTINE	-
Rozanolixizumab (Rystiggo)	SC	-	N/A :: SC :: weekly :: Weight-based SC weekly × 6 weeks per cycle; for AChR-positive generalized MG	-	Active infection	IgG levels; headache common; pyrexia; infection monitoring	-	ROUTINE	ROUTINE	-
Plasmapheresis (PLEX) - rescue (CPT 36514)	-	-	N/A :: - :: once :: 5-7 exchanges over 10-14 days; exchange 1-1.5 plasma volumes per session	-	Hemodynamic instability; sepsis; line contraindication; heparin allergy	BP during exchange; electrolytes (Ca, K, Mg); coagulation studies; fibrinogen; line site infection; hypotension	STAT	STAT	-	STAT
IVIG (rescue therapy)	PO	-	2 g/kg :: PO :: daily x 5 days :: 2 g/kg divided over 2-5 days (e.g., 0.4 g/kg/day × 5 days)	-	IgA deficiency; renal failure; recent thrombotic event	Pre-infusion IgA level; renal function; vital signs; headache (aseptic meningitis); thrombosis risk	STAT	STAT	-	STAT

Note: Complement inhibitors (eculizumab, ravulizumab, zilucoplan) and FcRn inhibitors (efgartigimod, rozanolixizumab) are FDA-approved for AChR antibody-positive generalized MG. They are NOT indicated for MuSK-positive or seronegative MG. Rituximab is first-line for MuSK-positive MG (excellent response rates).

3E. Surgical Treatment

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Thymectomy (VATS or robotic-assisted)	-	AChR-positive generalized MG, age 18-65 (MGTX trial); any age with thymoma; consider in AChR-positive ocular MG with suboptimal response	-	MuSK-positive MG (no proven benefit); medically unstable; uncontrolled MG (optimize first)	MGTX trial: thymectomy + prednisone superior to prednisone alone at 3 years; optimize MG before surgery (FVC >2L, no bulbar crisis); post-op ICU monitoring recommended	-	ROUTINE	ROUTINE	-
Thymectomy (median sternotomy)	-	Thymoma requiring complete resection; invasive thymoma	-	Same as above	More invasive; complete thymoma staging with Masaoka classification; consider neoadjuvant chemotherapy for advanced thymoma	-	ROUTINE	-	-
Extended thymectomy	-	Thymoma with suspected extra-thymic extension	-	Same as above	Includes removal of all anterior mediastinal fat; en bloc resection	-	ROUTINE	-	-

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4. OTHER RECOMMENDATIONS

4A. Referrals & Consults

Recommendation	ED	HOSP	OPD	ICU	Indication
Neuromuscular specialist/MG specialist referral	URGENT	URGENT	ROUTINE	URGENT	All new MG diagnoses for treatment planning and long-term management
Thoracic surgery referral	-	ROUTINE	ROUTINE	-	Thymoma present; AChR-positive generalized MG for thymectomy discussion
Pulmonology referral	-	ROUTINE	ROUTINE	URGENT	Respiratory compromise; pre-thymectomy pulmonary evaluation; chronic respiratory monitoring
Speech-language pathology (swallow evaluation)	-	URGENT	ROUTINE	URGENT	Bulbar symptoms: dysphagia, dysarthria, nasal speech; aspiration risk
Occupational therapy	-	ROUTINE	ROUTINE	-	ADL impairment; energy conservation; adaptive equipment
Physical therapy	-	ROUTINE	ROUTINE	ROUTINE	Generalized weakness; deconditioning; fall prevention; exercise prescription
Ophthalmology/Neuro-ophthalmology	-	ROUTINE	ROUTINE	-	Ocular MG; diplopia management; prism evaluation
Rheumatology referral	-	-	ROUTINE	-	Concurrent autoimmune disease (lupus, RA, thyroid disease)
Endocrinology referral	-	-	ROUTINE	-	Steroid-induced diabetes; thyroid disease management; osteoporosis
Psychiatry/Psychology referral	-	ROUTINE	ROUTINE	-	Depression; anxiety; adjustment to chronic diagnosis; steroid-induced psychiatric symptoms
Social work consult	-	ROUTINE	ROUTINE	-	Insurance navigation (biologic cost); disability evaluation; MG support resources
Respiratory therapy	STAT	STAT	-	STAT	FVC/NIF monitoring; ventilator management; BiPAP/CPAP evaluation
Nutrition/Dietetics	-	ROUTINE	ROUTINE	-	Dysphagia diet modification; weight management on steroids; nutritional optimization
Anesthesiology consultation (pre-thymectomy)	-	ROUTINE	ROUTINE	-	Pre-operative assessment; avoidance of neuromuscular blocking agents; post-op ventilation planning
Infusion center coordination	-	ROUTINE	ROUTINE	-	IVIG scheduling; rituximab infusion; complement inhibitor infusions
Pain management referral	-	-	EXT	-	Chronic pain from sustained muscle weakness or comorbid conditions
Palliative care (refractory cases)	-	-	EXT	-	Severely refractory MG with significant symptom burden; goals of care discussion
MG Foundation / Patient advocacy	-	-	ROUTINE	-	Patient support groups; educational materials; myasthenia.org referral

4B. Patient Instructions

Recommendation	ED	HOSP	OPD
Return to ED immediately if difficulty breathing, swallowing, or speaking	✓	✓	✓
Return to ED if new severe weakness, double vision worsening acutely, or unable to hold head up	✓	✓	✓
Take pyridostigmine 30-60 minutes BEFORE meals to help with chewing and swallowing	✓	✓	✓
Do NOT take pyridostigmine more frequently than prescribed (cholinergic crisis risk)	✓	✓	✓
Report excessive salivation, diarrhea, cramping, or muscle twitching (cholinergic side effects)	✓	✓	✓
Carry MG medical alert identification at all times	✓	✓	✓
Provide MG medication list to ALL healthcare providers (emergency, dental, surgical)	✓	✓	✓
Avoid extreme heat, hot baths/saunas (may worsen weakness)	-	✓	✓
Plan activities for times of best strength (usually morning after pyridostigmine)	-	✓	✓
Rest before meals if dysphagia present; eat smaller, more frequent meals	-	✓	✓
Do NOT stop prednisone or immunosuppressant abruptly (adrenal crisis/flare risk)	-	✓	✓
Avoid alcohol (potentiates weakness and interacts with medications)	-	✓	✓
Report any signs of infection immediately (fever, cough, dysuria) especially if on immunosuppression	-	✓	✓
Contact neurologist before taking any new medications (many drugs worsen MG)	-	✓	✓
Do NOT use over-the-counter magnesium-containing products without physician approval	-	✓	✓
Keep emergency contact numbers for MG specialist readily available	✓	✓	✓
Understand the difference between myasthenic crisis and cholinergic crisis	-	✓	✓
Monitor and report progressive difficulty climbing stairs, rising from chairs, or lifting arms above head	-	✓	✓

4C. Medications to Avoid in Myasthenia Gravis

Medication/Class	Risk Level	Details	Safe Alternative (if applicable)
ANTIBIOTICS
Aminoglycosides (gentamicin, tobramycin, amikacin, streptomycin)	HIGH	Impair presynaptic ACh release AND postsynaptic receptor function; can precipitate crisis	Use non-aminoglycoside antibiotics based on culture sensitivity
Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin)	HIGH	NMJ blocking effect; FDA black box warning for MG exacerbation	Beta-lactams, cephalosporins (generally safe)
Macrolides (azithromycin, erythromycin, clarithromycin)	MODERATE	Reports of MG worsening; telithromycin (CONTRAINDICATED - fatal cases)	Penicillins, cephalosporins
Tetracyclines (doxycycline, minocycline)	LOW-MODERATE	Rare reports of worsening; use with caution	Amoxicillin for common infections
Polymyxins (colistin)	HIGH	Strong NMJ blocking effect	Alternative per culture sensitivity
CARDIOVASCULAR
Beta-blockers (propranolol, metoprolol, atenolol)	MODERATE	May worsen weakness; impair NMJ transmission	ACE inhibitors, ARBs, CCBs (amlodipine)
Calcium channel blockers (verapamil, diltiazem)	MODERATE	Impair presynaptic calcium-dependent ACh release	Amlodipine (lower risk); ACE inhibitors
Procainamide	HIGH	NMJ blocking effect; may induce MG antibodies	Amiodarone (use cautiously)
Quinidine	HIGH	NMJ blocking effect; can precipitate crisis	Consult cardiology for alternatives
Lidocaine (IV)	MODERATE	High-dose IV may worsen NMJ transmission	Local/low-dose generally safe
Magnesium sulfate IV	HIGH	Inhibits presynaptic ACh release; can precipitate crisis	Avoid except life-threatening hypomagnesemia or eclampsia; ICU monitoring required
NEUROPSYCHIATRIC
D-penicillamine	HIGH	Can induce MG autoantibodies; CONTRAINDICATED	Trientine for Wilson disease
Phenytoin	MODERATE	May worsen NMJ transmission; case reports of MG exacerbation	Levetiracetam, lacosamide, valproate
Botulinum toxin	HIGH	Blocks presynaptic ACh release; CONTRAINDICATED in MG (systemic weakness risk)	Physical therapy; oral medications
Chlorpromazine, haloperidol	MODERATE	Reports of MG worsening	Atypical antipsychotics (quetiapine - use cautiously)
Lithium	MODERATE	May worsen NMJ transmission	Valproate, lamotrigine for mood stabilization
Benzodiazepines (high dose)	MODERATE	Respiratory depression; muscle relaxation compounds weakness	Low-dose short-acting with monitoring; melatonin for insomnia
ANESTHETIC/SURGICAL
Succinylcholine	HIGH	Unpredictable response: resistance (need higher dose) in chronic MG; prolonged block risk	Non-depolarizing agents at reduced dose with monitoring (rocuronium with sugammadex reversal)
Non-depolarizing NM blockers (vecuronium, pancuronium, rocuronium)	HIGH	Exaggerated and prolonged response; use 1/3 to 1/2 normal dose if necessary	Sugammadex for reversal of rocuronium; monitor with TOF
Volatile anesthetics (isoflurane, sevoflurane, desflurane)	MODERATE	May potentiate NMJ blockade; use reduced doses	TIVA (total intravenous anesthesia) considered safer
IMMUNE/CHECKPOINT
Immune checkpoint inhibitors (nivolumab, pembrolizumab, ipilimumab)	HIGH	Can trigger de novo MG or cause fatal exacerbation of pre-existing MG	CONTRAINDICATED in known MG; if must use for malignancy, extreme caution with close monitoring
Interferon-alpha	MODERATE	Can unmask or worsen autoimmune MG	Avoid if possible
OTHER
Quinine/tonic water	MODERATE	NMJ blocking effect	Avoid quinine-containing beverages
Statins (atorvastatin, simvastatin, rosuvastatin)	LOW	Rare myopathy; rare MG exacerbation reports; generally safe with monitoring	Continue if indicated; monitor for worsening
Iodinated contrast agents	LOW	Rare reports of transient worsening	Use with monitoring; pre-hydrate
Penicillamine	HIGH	Induces autoimmune MG; CONTRAINDICATED	Trientine

Note: This list is not exhaustive. ALWAYS check individual medications for MG safety before prescribing. When in doubt, consult neuromuscular specialist or pharmacist. Many drugs have case reports of MG exacerbation - use clinical judgment.

4D. Vaccinations

Recommendation	ED	HOSP	OPD	ICU	Notes
Meningococcal ACWY vaccine (Menactra or MenQuadfi)	-	URGENT	ROUTINE	-	REQUIRED ≥2 weeks before complement inhibitor therapy (eculizumab, ravulizumab, zilucoplan)
Meningococcal B vaccine (Bexsero or Trumenba)	-	URGENT	ROUTINE	-	REQUIRED ≥2 weeks before complement inhibitor therapy; 2-dose series
Influenza vaccine (inactivated)	-	ROUTINE	ROUTINE	-	Annually; safe in MG; use inactivated form (not live nasal spray)
Pneumococcal vaccines (PCV20 or PCV15 + PPSV23)	-	ROUTINE	ROUTINE	-	Recommended before immunosuppression; per CDC schedule
COVID-19 vaccine (mRNA)	-	ROUTINE	ROUTINE	-	Recommended; rare reports of MG flare but benefits outweigh risks; monitor 2-4 weeks post-vaccination
Hepatitis B vaccine	-	ROUTINE	ROUTINE	-	If seronegative and starting rituximab/immunosuppression
Shingles vaccine (Shingrix - recombinant, non-live)	-	-	ROUTINE	-	Age ≥50 or immunosuppressed; Shingrix is NOT a live vaccine (safe on immunosuppression)
AVOID all LIVE vaccines during immunosuppression	-	✓	✓	-	No MMR, varicella, live zoster (Zostavax), live influenza (FluMist), yellow fever, oral typhoid while on immunosuppressive therapy
Complete vaccinations BEFORE starting immunosuppression when possible	-	✓	✓	-	Ideally 4-6 weeks before rituximab, mycophenolate, or other immunosuppressants
VZV IgG titer (check before immunosuppression)	-	ROUTINE	ROUTINE	-	If non-immune: vaccinate with Varivax (live) before starting immunosuppression; wait 4 weeks after vaccination

4E. Pregnancy Considerations

Recommendation	ED	HOSP	OPD	ICU	Notes
MG course in pregnancy is unpredictable: 1/3 improve, 1/3 worsen, 1/3 unchanged	✓	✓	✓	✓	Highest risk of exacerbation in first trimester and postpartum
Pyridostigmine is safe in pregnancy (Category B equivalent)	✓	✓	✓	✓	Continue as needed; IV neostigmine safe in labor
Prednisone is relatively safe in pregnancy	-	✓	✓	-	Use lowest effective dose; monitor for gestational diabetes; prednisone preferred (metabolized by placenta)
Azathioprine may be continued in pregnancy if necessary	-	✓	✓	-	Benefits may outweigh risks; discuss with maternal-fetal medicine
Mycophenolate is CONTRAINDICATED in pregnancy (Category D/X)	✓	✓	✓	✓	Teratogenic; must be stopped ≥6 weeks before conception; REMS pregnancy prevention program
Methotrexate is CONTRAINDICATED in pregnancy (Category X)	✓	✓	✓	✓	Teratogenic/abortifacient; stop ≥3 months before conception
Rituximab: stop ≥12 months before conception	-	-	✓	-	B-cell depletion risk to neonate; limited data
Complement/FcRn inhibitors: insufficient pregnancy data	-	✓	✓	-	Discuss risks/benefits with MG specialist and MFM
IVIG is safe in pregnancy	-	✓	✓	✓	Preferred rescue therapy if needed during pregnancy
PLEX is safe in pregnancy	-	✓	-	✓	Preferred rescue therapy; monitor for hypotension
Monitor neonate for transient neonatal MG	✓	✓	✓	✓	Occurs in 10-20% of babies born to MG mothers; maternal AChR antibodies cross placenta; self-limited (resolves within weeks); NICU alert
Avoid magnesium sulfate for eclampsia in MG	✓	✓	✓	✓	Magnesium blocks NMJ; may precipitate crisis; use alternative tocolytics/anticonvulsants (levetiracetam)
Breastfeeding generally safe on pyridostigmine and prednisone	-	✓	✓	-	Avoid breastfeeding on mycophenolate, methotrexate, cyclophosphamide
Plan delivery at facility with NICU and neurology support	-	✓	✓	-	Vaginal delivery preferred; cesarean only for obstetric indications; regional anesthesia preferred over general
Maternal-fetal medicine co-management for all MG pregnancies	-	✓	✓	-	Pre-conception counseling recommended; multidisciplinary approach

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═══════════════════════════════════════════════════════════ SECTION B: REFERENCE (Expand as Needed) ═══════════════════════════════════════════════════════════

5. DIFFERENTIAL DIAGNOSIS

Alternative Diagnosis	Key Distinguishing Features	Tests to Differentiate
Lambert-Eaton Myasthenic Syndrome (LEMS)	Proximal weakness with improvement after exertion (facilitation); autonomic dysfunction; dry mouth; associated with SCLC; depressed reflexes that improve post-exercise	VGCC antibody (P/Q-type); incremental response on RNS at 50 Hz; CT chest for malignancy
Botulism	Acute onset descending paralysis; dilated/fixed pupils; recent ingestion of canned food or wound; autonomic dysfunction; no prior NMJ disease	Stool/serum botulinum toxin assay; EMG: BSAP pattern; incremental response on high-frequency RNS
Congenital Myasthenic Syndromes (CMS)	Childhood onset; family history; seronegative; variable inheritance patterns; specific gene mutations	Genetic testing (CMS gene panel: CHRNE, DOK7, RAPSN, CHAT, COLQ); no autoantibodies
Thyroid ophthalmopathy (Graves)	Proptosis; restrictive (not fatigable) diplopia; lid lag; thyroid dysfunction; MRI shows enlarged EOMs	TSH, free T4, TSI, orbital MRI showing EOM enlargement (not NMJ issue)
Progressive external ophthalmoplegia (PEO)	Slowly progressive bilateral ptosis and ophthalmoparesis; non-fatigable; no diurnal variation; may have pigmentary retinopathy	Muscle biopsy (ragged red fibers, COX-negative); mitochondrial DNA analysis
Oculopharyngeal muscular dystrophy (OPMD)	Late-onset (>40) progressive ptosis and dysphagia; autosomal dominant; no fatigability; specific ethnic prevalence (French-Canadian, Bukharan Jewish)	Genetic testing (PABPN1 gene, GCN trinucleotide repeat); CK may be mildly elevated
Motor neuron disease (ALS/PBP)	Progressive weakness without fatigability; fasciculations; UMN signs (hyperreflexia, Babinski); no sensory loss; bulbar onset may mimic MG	EMG/NCS: active denervation, fasciculations; normal RNS; no antibodies
Inflammatory myopathy (PM/DM/IBM)	Proximal weakness without fatigability; elevated CK; skin findings in DM; no ptosis/diplopia (usually); IBM with grip/quad weakness	CK; myositis antibody panel; EMG: myopathic pattern; muscle biopsy
Brainstem stroke	Acute onset; cranial nerve palsies without fatigability; other focal neurological signs; vascular risk factors	Brain MRI with DWI; MRA; CTA
Miller Fisher syndrome (GBS variant)	Acute ophthalmoplegia, ataxia, areflexia; post-infectious; no fatigability	Anti-GQ1b antibody; CSF albuminocytologic dissociation; NCS (reduced SNAPs)
Myotonic dystrophy	Ptosis and facial weakness; myotonia (delayed relaxation); distal > proximal weakness; cataracts; cardiac conduction abnormalities	Genetic testing (DMPK CTG repeat for DM1, CNBP CCTG repeat for DM2); EMG: myotonic discharges
Chronic inflammatory demyelinating polyneuropathy (CIDP)	Progressive proximal and distal weakness; hyporeflexia/areflexia; sensory involvement; elevated CSF protein	NCS: demyelinating pattern; CSF protein; nerve biopsy
Sarcoidosis (neuromuscular)	Granulomatous myopathy or cranial neuropathy; systemic involvement (lungs, skin, eyes); elevated ACE	ACE level; chest CT; biopsy (non-caseating granulomas); gallium scan
Drug-induced MG	Temporal correlation with offending drug (D-penicillamine, checkpoint inhibitors, statins); antibodies may be present	Drug history; antibody testing; improvement after drug withdrawal

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6. MONITORING PARAMETERS

6A. Acute Monitoring (ED / Inpatient / ICU)

Parameter	Frequency	Target/Threshold	Action if Abnormal
Forced vital capacity (FVC)	Q4-6h in acute; Q shift if stable	>20 mL/kg (>1.5 L)	If <15 mL/kg or <1 L: impending respiratory failure, prepare for intubation; ICU transfer
Negative inspiratory force (NIF/MIP)	Q4-6h in acute; Q shift if stable	More negative than -40 cm H2O	If weaker than -20 cm H2O: intubate; -20 to -30 = ICU monitoring
Peak expiratory flow (PEF)	Q4-6h in acute	>200 L/min	Declining PEF = weakening respiratory muscles
Oxygen saturation (SpO2)	Continuous in acute	>94%	Supplemental O2; BiPAP; intubation if declining
Swallow function assessment	Daily; each meal if bulbar symptoms	Safe oral intake	NPO if aspiration risk; NG tube or modified diet; SLP consult
Neurologic exam (MG-specific)	Q shift inpatient; BID in ICU	Stable or improving strength	If worsening: reassess pyridostigmine dose; consider IVIG/PLEX; check for cholinergic crisis
Blood glucose	Q6h during IV/high-dose steroids	<180 mg/dL	Insulin sliding scale; endocrine consult if persistent >250
Blood pressure	Q shift during steroids	<160/100 mmHg	Antihypertensives PRN
Temperature	Q shift	Afebrile	Infection workup if febrile (infection is leading MG crisis trigger)
Electrolytes (K, Mg, Ca, Phos)	Daily while acute	Normal ranges	Replace aggressively; hypokalemia and hypomagnesemia worsen NMJ transmission
I/O and daily weight	Daily (inpatient)	Euvolemic	Adjust fluids; diuretics if overload
Cardiac monitoring	Continuous if on neostigmine IV; during PLEX	Normal rhythm	Atropine for bradycardia; PLEX can cause electrolyte-mediated arrhythmias
Mood and sleep assessment	Daily during steroids	No psychosis, mania, severe insomnia	Psychiatry consult; consider dose adjustment
Aspiration precautions	Throughout admission if bulbar symptoms	No aspiration events	HOB elevated; thickened liquids; SLP-guided diet

6B. Chronic/Outpatient Monitoring

Parameter	Frequency	Target/Threshold	Action if Abnormal
MG-ADL score	Each clinic visit	Minimal symptom score (goal <6)	Escalate therapy if increasing; assess adherence
QMG score (Quantitative MG Score)	Each clinic visit or q3 months	Improvement ≥3.5 points = clinically meaningful	Treatment escalation if not meeting goals
FVC (office spirometry)	Each visit initially; q3-6 months when stable	>80% predicted	Pulmonology referral if declining; assess respiratory muscle involvement
CBC with differential	Q2-4 weeks during AZA/MMF titration; then q3 months	WBC >3000; ANC >1500; lymphocytes 600-1000 (on AZA)	Hold/reduce immunosuppressant if cytopenic; G-CSF if severe neutropenia
LFTs	Q2-4 weeks during AZA/MMF/MTX titration; then q3 months	AST/ALT <3× ULN	Reduce or hold offending agent; hepatology referral if persistent
Renal function (BUN/Cr)	Q3 months on tacrolimus/cyclosporine; q6 months otherwise	Normal eGFR	Dose adjustment; avoid nephrotoxins
Fasting glucose / HbA1c	Q3 months while on steroids	HbA1c <7%	Endocrinology referral; steroid dose reduction; oral hypoglycemic or insulin
DEXA scan (bone density)	Baseline if starting chronic steroids; repeat q2 years	T-score > -1.0	Bisphosphonate; calcium/vitamin D; endocrinology referral
Ophthalmologic exam	Annually if on chronic steroids; q6 months first year on steroids	No cataracts or glaucoma	Ophthalmology referral for cataracts (steroid-induced); IOP monitoring
CD19/CD20 B-cell counts (if on rituximab)	Q3-6 months	Depleted B-cells (therapeutic); monitor for recovery	Redose rituximab when B-cells recover and symptoms worsen
Immunoglobulin levels (IgG, IgA, IgM)	Q6 months if on rituximab/chronic immunosuppression	IgG >400 mg/dL	IVIG replacement if symptomatic hypogammaglobulinemia with recurrent infections
IgG level (if on FcRn inhibitor)	Before each treatment cycle	~70% reduction expected during treatment	Guide retreatment timing; monitor for infection
Tacrolimus/cyclosporine trough level	Q1-2 weeks during titration; then q1-3 months	Tacrolimus 5-10 ng/mL; cyclosporine 100-150 ng/mL	Dose adjustment based on level and clinical response
CT chest (thymoma surveillance)	Annually × 5 years after thymectomy for thymoma; if not resected: q6-12 months	No recurrence or growth	Thoracic surgery referral for recurrence; consider radiation/chemotherapy
LDH, reticulocyte count, haptoglobin (if on complement inhibitor)	Q2-4 weeks initially; then q3 months	No hemolysis	If discontinuing complement inhibitor: monitor closely for rebound hemolysis
Meningococcal infection surveillance (if on complement inhibitor)	Each visit; patient education	No signs of meningococcal disease	Emergency evaluation for fever, headache, neck stiffness, rash; ensure vaccination current; ciprofloxacin prophylaxis
Vitamin D level	Annually	>30 ng/mL	Supplement 2000-5000 IU daily
Thyroid function (TSH)	Annually (autoimmune overlap)	Normal	Endocrinology referral if abnormal

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7. DISPOSITION CRITERIA

Disposition	Criteria
Discharge home	Mild symptoms (ocular only or mild generalized); FVC >60% predicted and stable; adequate oral intake; pyridostigmine optimized; reliable follow-up within 1-2 weeks; understands return precautions; crisis action plan reviewed
Admit to floor (general neurology)	Moderate generalized weakness; FVC 40-60% predicted and stable; dysphagia requiring diet modification but tolerating PO; new diagnosis requiring expedited workup; steroid initiation with concern for transient worsening; IVIG infusion
Admit to step-down/telemetry	FVC 30-40% predicted or declining trend; moderate bulbar symptoms; starting PLEX; significant comorbidities requiring closer monitoring; recent cholinergic vs myasthenic crisis distinction unclear
Admit to ICU	FVC <30% predicted or <1 L; NIF weaker than -25 cm H2O; progressive respiratory failure; impending intubation; active myasthenic crisis; severe bulbar dysfunction with aspiration; hemodynamic instability during PLEX
Transfer to higher level	PLEX needed but unavailable; neuromuscular specialist not available; ICU capability needed but not present; thymectomy needed at specialized center
Discharge from hospital	FVC >50% predicted and improving; adequate oral intake; stable on oral medications; immunotherapy plan established; outpatient follow-up scheduled within 1-2 weeks; patient and family educated on crisis recognition

MGFA Clinical Classification

Class	Description
Class I	Any ocular muscle weakness; may have weakness of eye closure; all other muscle strength is normal
Class II	Mild weakness affecting muscles other than ocular; may also have ocular weakness of any severity
Class IIa	Predominantly affecting limb, axial muscles, or both; may also have lesser involvement of oropharyngeal muscles
Class IIb	Predominantly affecting oropharyngeal, respiratory muscles, or both; may also have lesser or equal involvement of limb, axial muscles, or both
Class III	Moderate weakness affecting muscles other than ocular; may also have ocular weakness of any severity
Class IIIa	Predominantly affecting limb, axial muscles, or both; may also have lesser involvement of oropharyngeal muscles
Class IIIb	Predominantly affecting oropharyngeal, respiratory muscles, or both; may also have lesser or equal involvement of limb, axial muscles, or both
Class IV	Severe weakness affecting muscles other than ocular; may also have ocular weakness of any severity
Class IVa	Predominantly affecting limb, axial muscles, or both; may also have lesser involvement of oropharyngeal muscles
Class IVb	Predominantly affecting oropharyngeal, respiratory muscles, or both; may also have lesser or equal involvement of limb, axial muscles, or both
Class V	Defined by intubation, with or without mechanical ventilation, except when employed during routine postoperative management (intubation for management of airway = Class V)

MG-ADL (Activities of Daily Living) Score

Domain	0	1	2	3
Talking	Normal	Intermittent slurring or nasal speech	Constant slurring or nasal but can be understood	Difficult to understand speech
Chewing	Normal	Fatigue with solid food	Fatigue with soft food	Gastric tube
Swallowing	Normal	Rare episode of choking	Frequent choking necessitating diet changes	Gastric tube
Breathing	Normal	Shortness of breath with exertion	Shortness of breath at rest	Ventilator dependent
Ability to brush teeth or comb hair	Normal	Extra effort but no rest needed	Rest periods needed	Cannot do one of these functions
Ability to arise from chair	Normal	Mild, sometimes uses arms	Moderate, sometimes fails on first attempt	Severe, requires assistance
Double vision	None	Occurs but not daily	Daily but not constant	Constant
Eyelid droop	None	Occurs but not daily	Daily but not constant	Constant

Total MG-ADL Score: 0-24. Score ≥6 generally indicates suboptimal control. Improvement ≥2 points = clinically meaningful. Validated for treatment response monitoring.

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8. EVIDENCE & REFERENCES

Recommendation	Evidence Level	Source
AChR antibody testing for MG diagnosis	Class I	Gilhus NE et al. Nat Rev Dis Primers 2019
AChR binding + blocking + modulating antibodies increases sensitivity to ~95%	Class II	Howard JF. Clinical Overview of MG. UpToDate 2024
MuSK antibody testing in seronegative MG	Class I	Hoch W et al. Nat Med 2001; Evoli A et al. Brain 2003
LRP4 antibody in double-seronegative MG	Class II	Higuchi O et al. Ann Neurol 2011; Zisimopoulou P et al. J Autoimmun 2014
RNS: ≥10% decrement diagnostic criterion	Class I, Level A	AANEM Practice Parameter 2001; Sanders DB et al.
SFEMG most sensitive diagnostic test (95-99%)	Class I, Level A	Sanders DB, Stalberg EV. Muscle Nerve 1996
Ice pack test for ocular MG (~80% sensitivity)	Class II, Level B	Cubero E et al. Neurology 2000
CT chest for thymoma screening in all MG patients	Class I, Level A	Gilhus NE et al. Nat Rev Dis Primers 2019; AAN Guidelines
Pyridostigmine as first-line symptomatic therapy	Class I, Level A	Mehndiratta MM et al. Cochrane 2011
MuSK-MG often refractory to pyridostigmine	Class II	Evoli A et al. Brain 2003; Guptill JT et al. 2011
Prednisone for MG immunosuppression	Class I, Level A	Palace J et al. Neurology 1998
Steroid-induced transient worsening in ~50% of MG patients	Class II	Bae JS et al. Muscle Nerve 2006
Mycophenolate mofetil as steroid-sparing agent	Class I (negative RCTs but widely used)	Sanders DB et al. Neurology 2008; MG Study Group (note: RCTs were short-duration)
Azathioprine as steroid-sparing agent	Class I, Level B	Palace J et al. Neurology 1998
TPMT testing before azathioprine	Class I, Level A	Pharmacogenomics guidelines; FDA labeling
Rituximab for MuSK-positive MG	Class II (observational)	Diaz-Manera J et al. Neurology 2012; Hehir MK et al. Neurology 2017
Rituximab for AChR-positive refractory MG	Class II	Tandan R et al. (BeatMG trial) Lancet Neurol 2023
Eculizumab for AChR-positive generalized MG	Class I (REGAIN trial)	Howard JF et al. Lancet Neurol 2017
Ravulizumab for AChR-positive generalized MG	Class I (CHAMPION-MG)	Vu T et al. NEJM Evidence 2022
Zilucoplan for AChR-positive generalized MG	Class I (RAISE trial)	Howard JF et al. Lancet Neurol 2023
Efgartigimod for AChR-positive generalized MG	Class I (ADAPT trial)	Howard JF et al. Lancet Neurol 2021
Rozanolixizumab for AChR-positive generalized MG	Class I (MycarinG trial)	Bril V et al. Lancet Neurol 2023
IVIG for MG acute exacerbation and maintenance	Class I, Level A	Gajdos P et al. Cochrane 2012
PLEX for myasthenic crisis	Class I, Level A	Gajdos P et al. Cochrane 2012
IVIG equivalent to PLEX for MG exacerbation	Class I	Barth D et al. Neurology 2011
Thymectomy for non-thymomatous AChR-positive MG	Class I (MGTX trial)	Wolfe GI et al. NEJM 2016
MGTX trial: thymectomy + prednisone superior at 3 years	Class I	Wolfe GI et al. NEJM 2016; 5-year extension data 2019
Medications to avoid in MG (comprehensive review)	Class II-III	Gilhus NE. NEJM 2016; Sheikh S et al. Muscle Nerve 2021
FVC <15 mL/kg predicts need for intubation	Class II, Level B	Thomas CE et al. Neurology 1997
NIF weaker than -20 cm H2O: intubation threshold	Class II, Level B	Thomas CE et al. Neurology 1997
MG-ADL as validated outcome measure	Class I	Wolfe GI et al. Neurology 1999
QMG score as validated outcome measure	Class I	Barohn RJ et al. Ann NY Acad Sci 1998
MGFA Clinical Classification system	Consensus	Jaretzki A et al. Neurology 2000
Meningococcal vaccination before complement inhibitors	FDA requirement	FDA REMS for eculizumab/ravulizumab/zilucoplan
Pregnancy management in MG	Class II-III	Norwood F et al. J Neurol Neurosurg Psychiatry 2014; Batocchi AP et al. Neurology 1999
Transient neonatal MG in 10-20% of births	Class II	Hoff JM et al. Neurology 2003

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CHANGE LOG

v1.0 (January 27, 2026) - Initial creation - Section 1: 46 laboratory tests across 3 tiers (17 core, 18 extended, 11 rare/specialized) - AChR binding/blocking/modulating antibodies as core - MuSK, LRP4, anti-striated muscle, anti-titin, anti-RyR as extended - VGCC, paraneoplastic panel, CMS genetics as rare - Section 2: Imaging and studies across 3 tiers plus bedside tests - CT/MRI chest for thymoma screening - RNS and SFEMG as electrodiagnostic studies - Ice pack test, rest test, bedside fatigability tests - FVC and NIF monitoring protocols - Section 3: Treatment across 5 subsections - 3A: Cholinesterase inhibitors (7 items including pyridostigmine IR/SR/liquid, neostigmine IV) - 3B: Corticosteroids (9 items including gradual/rapid escalation, pulse therapy, bone/GI protection, PCP prophylaxis) - 3C: Steroid-sparing agents (7 items: mycophenolate, azathioprine, tacrolimus, cyclosporine, methotrexate, cyclophosphamide, maintenance IVIG) - 3D: Biologics and rescue (10 items: rituximab, eculizumab, ravulizumab, zilucoplan, efgartigimod IV/SC, rozanolixizumab, PLEX, IVIG rescue) - 3E: Surgical treatment (3 items: VATS/robotic thymectomy, sternotomy, extended thymectomy) - Section 4: Recommendations across 5 subsections - 4A: 18 referrals including MG Foundation/patient advocacy - 4B: 18 patient instructions - 4C: 28 medications to avoid organized by drug class - 4D: 10 vaccination items including meningococcal requirements - 4E: 15 pregnancy considerations - Section 5: 14 differential diagnoses - Section 6: Monitoring parameters - 6A: 14 acute monitoring parameters with FVC/NIF thresholds - 6B: 18 chronic monitoring parameters - Section 7: Disposition criteria (6 levels), MGFA Classification (11 classes/subclasses), MG-ADL score (8 domains) - Section 8: 37 evidence citations