Myasthenia Gravis Activities of Daily Living (MG-ADL)

Why use it

MG-ADL provides a validated, efficient, patient-reported assessment of MG symptom burden that captures both bulbar and limb domains without requiring a neurological examination. It takes under 5 minutes to complete and is sensitive to treatment-related change, making it ideal for both clinical practice monitoring and clinical trial endpoints. The 2-point MCID is well established, allowing clinicians to determine whether observed changes represent meaningful improvement. As a patient-reported tool, it captures symptom experiences that may not be apparent on examination.

About

The Myasthenia Gravis Activities of Daily Living (MG-ADL) scale is a validated, patient-reported outcome measure developed by Wolfe and colleagues and published in Neurology in 1999. It was designed to quantify the impact of myasthenia gravis (MG) on key functional activities of daily living in a brief, practical format suitable for routine clinical use. The MG-ADL comprises 8 items assessing the most clinically relevant symptom domains of MG: talking, chewing, swallowing, breathing, hygiene (brushing teeth/combing hair), arising from a chair, double vision (diplopia), and eyelid drooping (ptosis). Each item is scored on a 4-point scale (0–3), generating a total score of 0 to 24. MG-ADL has become the most widely used patient-reported endpoint in MG clinical trials, endorsed by the Myasthenia Gravis Foundation of America (MGFA) as a standard outcome measure. The scale correlates well with the Quantitative MG (QMG) Score and MGFA Clinical Classification. MG-ADL is sensitive to treatment change and is used in pivotal trials of eculizumab (REGAIN), efgartigimod (ADAPT), rozanolixizumab, and other novel MG therapies as a primary or key secondary endpoint. A minimal clinically important difference (MCID) of 2 points has been established for the MG-ADL.

When to use

• Baseline functional assessment at MG diagnosis to establish symptom severity
• Serial monitoring during treatment to assess response — administer at each clinic visit
• Before and after initiation or dose adjustment of immunosuppressive therapy (pyridostigmine, prednisone, azathioprine, mycophenolate, rituximab, eculizumab, efgartigimod)
• Screening for myasthenic crisis risk — rapidly increasing MG-ADL, particularly Item 4 (breathing), warrants urgent evaluation
• Clinical trial enrollment, randomization, and primary endpoint assessment in MG trials
• Post-thymectomy monitoring to track functional improvement
• Assessment before and after IVIG or plasma exchange courses

Formula

Pearls & pitfalls

• Item 4 (Breathing) is the most critical individual item — a score of 2 (dyspnea at rest) or 3 (ventilator-dependent) requires immediate respiratory assessment regardless of total score. Forced vital capacity (FVC) and negative inspiratory force (NIF) should be measured urgently.
• The MCID for MG-ADL is 2 points — a change of ≥2 from baseline represents a clinically meaningful treatment response in randomized controlled trials.
• MG-ADL correlates well with the QMG (Quantitative MG) score (r=0.73 in the original validation study) and is superior to QMG for assessing patient-reported functional impact.
• Ocular MG (ptosis + diplopia without other involvement) often produces low MG-ADL scores that do not reflect the significant quality-of-life impact of visual symptoms — MG-QOL15 may better capture this population.
• The MGFA Task Force recommends the MG-ADL as a minimal dataset for all MG clinical encounters and recommends administering it before the physician examination to minimize examiner influence.
• In the REGAIN trial (eculizumab), a mean reduction in MG-ADL of 4.2 points vs 2.3 for placebo (p<0.001) established eculizumab efficacy for AChR antibody-positive generalized MG.
• In the ADAPT trial (efgartigimod), MG-ADL responder rate (≥2-point reduction) was 68% vs 30% for placebo, establishing efgartigimod as an effective FcRn inhibitor for generalized MG.
• Worsening of MG-ADL despite stable therapy should prompt evaluation for precipitants: infection, new medications (beta-blockers, aminoglycosides, fluoroquinolones, magnesium), thyroid disease, and thymoma recurrence.
• Post-intervention status (PIS) categories defined by MGFA — complete stable remission, pharmacological remission, minimal manifestations — can be mapped alongside MG-ADL for a comprehensive outcome assessment.

Next steps

MG-ADL 0–4 (Minimal/Mild): Mild symptomatic impact. Optimize cholinesterase inhibitor dosing (pyridostigmine). Consider immunosuppressive therapy if symptoms are persistent or impacting quality of life. Monitor every 3–6 months. MG-ADL 5–9 (Moderate): Significant functional impairment. Immunosuppressive therapy is indicated (corticosteroids ± steroid-sparing agent: azathioprine 2–3 mg/kg/day or mycophenolate 1–1.5 g BID). Re-evaluate response at 4–8 weeks. Consider specialist MG center referral. MG-ADL 10–14 (Severe): Severe impairment affecting major ADLs. Consider escalation to biologic therapy: eculizumab (FDA-approved for AChR antibody-positive generalized MG), efgartigimod alpha (anti-FcRn), rozanolixizumab. Assess dysphagia and aspiration risk. Evaluate respiratory function. MG-ADL ≥15 (Critical): Very severe. Assess for impending myasthenic crisis (Item 4 score ≥2 is an alarm sign). Consider hospitalization, IVIG 2 g/kg or plasma exchange (5 exchanges). Evaluate ICU-level monitoring. Item 4 ≥2: urgent respiratory function assessment (FVC, NIF).

Evidence

Wolfe GI et al. Myasthenia gravis activities of daily living profile. Neurology. 1999;52(7):1487-1489. PMID:10227640. Original validation in 40 patients. Correlation with QMG r=0.73. Sensitivity to change demonstrated in treatment response studies. Burns TM et al. Construction of an efficient evaluative instrument for myasthenia gravis. Muscle Nerve. 2008;37(4):473-480. MCID established as 2 points in multiple randomized controlled trials. Used as primary endpoint in REGAIN (eculizumab), ADAPT (efgartigimod), BeatMG (rituximab), and multiple other MG trials.

References

1. Wolfe GI et al. Myasthenia gravis activities of daily living profile. Neurology. 1999;52(7):1487-1489. — link
2. Burns TM et al. Construction of an efficient evaluative instrument for myasthenia gravis: the MG Composite. Muscle Nerve. 2008;37(4):473-480. — link
3. Howard JF et al. Safety and efficacy of eculizumab in anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis (REGAIN). Lancet Neurol. 2017;16(12):976-986. — link
4. Howard JF et al. Efgartigimod for the treatment of generalized myasthenia gravis (ADAPT). Lancet Neurol. 2021;20(7):526-536. — link
5. Narayanaswami P et al. International consensus guidance for management of myasthenia gravis: 2020 update. Neurology. 2021;96(3):114-122. — link