Female doctor talking to male patient looking at iPad device

Multifocal Motor Neuropathy

Multifocal motor neuropathy (MMN) is an immune-mediated demyelinating motor neuropathy that causes slowly progressive asymmetric distal limb weakness, with no objective sensory loss.1,2,3

Signs and symptoms of MMN include weakness in the hands, lower arms, and the lower limbs. Patients may experience cramping, involuntary contractions or twitching, and wasting of affected muscles.1 MMN is commonly misdiagnosed, which can lead to inappropriate treatment and progression of muscle weakness and/or disability.3,4,5,6,7

Human anatomy educational diagram with peripheral nerve highlight

Epidemiology

In the U.S., the prevalence of MMN is approximately 1 to 2 cases per 100,000 people, and the disease can mimic the early symptoms of amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s disease), although it only has a third of the prevalence of ALS.3,8,9,10

First symptoms appear before the age of 50 in almost 80% of patients, with the mean age of onset at 40 years (range 20 to 70 years).3 Men are 2.7 times more likely to be affected by MMN than women.6

Pathophysiology

The exact mechanism of the disease is unknown.3 It is hypothesized that the slowed or faulty nerve conduction in MMN is due to demyelination of the myelin sheath or injury to the nerve itself by:3,13

  • Binding of anti-IgM antibodies to ganglioside-monosialic acid (GM1)
  • Complement protein recruitment
  • Membrane attack complex recruitment
  • Axonal damage

Conduction block (CB) is the characteristic finding in MMN and is believed to be the underlying electrophysiological cause of muscle weakness.4 However, axon loss rather than CB is the most important determinant of permanent weakness and disability.3

Diagnosis

The diagnosis of MMN requires clinical weakness without objective sensory loss and without upper motor neuron signs:5,11

  • In the distribution of ≥2 named nerves due to CB
  • In ≥2 motor nerves outside of common entrapment sites

Normal results are required for sensory nerve conduction studies.5 Laboratory and electrodiagnostic tests may help confirm the diagnosis but may not be definitive:3

  • CB on nerve conduction study: CB is the hallmark electrophysiological finding, however, it may not be detected and is not always necessary for diagnosis3
  • Immunoglobulin M (IgM) antibodies to GM1
    • Present in approximately 50% of patients with MMN3
    • Antibodies against other gangliosides are present in a low percentage of patients and therefore have little diagnostic utility3
  • Cerebrospinal fluid (CSF) protein elevation: Normal or mild elevation (<1 g/L) in approximately 30% of patients3
  • Magnetic resonance imaging (MRI): Abnormal signal on brachial plexus MRI in approximately 40 to 50% of patients, including increased signal intensities in the brachial plexus and ventral rami of the roots on T2-weighted images which correspond to symptom distribution3
  • Nerve biopsy: Primary axonal degeneration and/or myelin pathology (limited studies)3,4,12

Navigating MMN

A differential diagnosis is necessary to differentiate MMN from diseases with similar symptoms, such as ALS and chronic inflammatory demyelinating polyneuropathy (CIDP).3,4,5 Even with an accurate diagnosis, treatment options for MMN are limited and are aimed at modulating the aberrant immune responses.4,11,14,15

The goals of treatment are to:

  • Reverse motor CB15

  • Limit damage to axons to prevent permanent nerve damage8,15

  • Limit damage to myelin sheath and mitigate impaired signal conduction in nerves3,11

  • Improve strength and reduce disability4,7,14

Scientific Congresses and Resources

This is not intended to be a comprehensive resource of all congresses and congress materials across therapeutic and disease areas. Congress materials may include information about investigational use(s) of compounds/products that are not approved for use by the U.S. Food and Drug Administration (FDA) and/or are inconsistent with the Prescribing Information. Takeda does not recommend the use of any Takeda product beyond the approved labeling. Any decisions regarding the usage of a Takeda product beyond the approved labeling are left to the discretion of the healthcare professional. Takeda makes no representations about whether investigational compounds or unapproved uses will be approved by the FDA.

Immunoglobulin National Society (IgNS), 2025

October 16 - 19, 2025 | Link to Event

National conference of IgNS bringing together professionals and practitioners from all disciplines and clinical specialties to advance Ig therapy practice, while providing networking and comprehensive education opportunities.

American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM), 2025

October 29 - November 1, 2025 | Link to Event

Annual meeting dedicated to the advancement of neuromuscular, musculoskeletal, and electrodiagnostic medicine.

American College of Allergy, Asthma & Immunology (ACAAI), 2025

November 6 - 10, 2025 | Link to Event

Global meeting featuring thought leaders from around the world focused on advancing patient care in allergy and immunology.

Annual Meeting American Academy of Allergy Asthma and Immunology (AAAAI), 2026

February 27 - March 2, 2026 | Link to Event

Premier global educational event for allergists and immunologists, with thousands of attendees each year, discussing allergies, asthma, and immune deficiency disorders.

American Academy of Neurology (AAN), 2026

April 18 - 22, 2026 | Link to Event

Each year, the American Academy of Neurology's Annual Meeting offers a robust lineup of diverse learning opportunities covering nearly every topic and subspecialty, helping you stay up to date on the latest trusted science and essential education.

National Home Infusion Association (NHIA), 2026

April 18 - 22, 2026 | Link to Event

Brings together home and alternate site infusion professionals for four days of networking, education, and exhibits. The expo features companies displaying the latest products and services supporting the industry.

Hereditary Angioedema National Summit (HAEA), 2025

July 10 - 13, 2025

This event brings together over 1200 HAE community members, including families, caregivers, healthcare professionals, and pharmaceutical representatives.

Takhzyro® (lanadelumab-flyo)

  • Longitudinal Trend in Attack Outcomes in Patients With Hereditary Angioedema Receiving Long-term Prophylaxis with Lanadelumab: An Observational Study
  • Physician-Reported Attack Rates and Attack Characteristics Among Patients With Hereditary Angioedema Who Extended Dosing With Lanadelumab: An EMPOWER Study Analysis
  • Treatment Outcomes With Lanadelumab by Baseline Hereditary Angioedema Activity: EMPOWER/ENABLE Analysis

Eastern Allergy Conference (EAC), 2025

May 29 - June 1, 2025

Regional annual conference discussing the most current information from top experts in allergy, asthma, and immunology.

Takhzyro® (lanadelumab-flyo)

  • Lanadelumab’s Sustained Effectiveness and Safety for Hereditary Angioedema Long-Term Prophylaxis in Patients From Puerto Rico: Final Results From the EMPOWER Study
  • Understanding the Impact of Long-Term Prophylaxis Switches for Patients With Hereditary Angioedema.

American Thoracic Society (ATS), 2025

May 16 - 21, 2025

International conference showcasing the latest advances in pulmonary disease, critical illness, and sleep disorders for scientists and clinicians at all stages of their careers.

Glassia® [Alpha1- Proteinase Inhibitor (Human)]

  • Application of an Artificial Intelligence Model to Detect Alpha-1 Antitrypsin Deficiency: Characterizing the Study Population
  • Application of an Artificial Intelligence Model to Detect Alpha-1 Antitrypsin Deficiency: Model Performance

Clinical Immunology Society (CIS), 2025

May 1 - 4, 2025

Annual meeting with the goal of providing a stimulating forum with presentations and discussions on the latest advances in clinical immunology, including primary immunodeficiencies and immune dysregulatory diseases.

American Academy of Neurology (AAN), 2025

April 5 - 9, 2025

Annual meeting in neurology promoting high quality patient-centric care in a variety of topics and specialties through various learning formats.

  • Real-World Characteristics and Disease Management for a Virtual Longitudinal Cohort of Patients with Chronic Inflammatory Demyelinating Polyneuropathy

Academy of Managed Care Pharmacy (AMCP), 2025

March 31 - April 3, 2025

Large assembly of pharmacy and healthcare professionals dedicated to the issues of managed care pharmacy, offering immersive education sessions and keynote presentations.

  • Epidemiology, Patient Characteristics, Real-World Treatment Patterns, and Outcomes for Patient with Multifocal Motor Neuropathy (MMN)
  • Disease Severity and Healthcare Resource Utilization for Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Multifocal Motor Neuropathy: Results from an Integrated Database

National Home Infusion Association (NHIA), 2025

March 29 - April 2, 2025

Annual conference ideal for infusion professionals or those seeking opportunities in the industry to come together and explore the latest trends in offering home-based services. 

Annual Meeting American Academy of Allergy Asthma and Immunology (AAAAI), 2025

February 28 - March 3, 2025

Premier global educational event for allergists and immunologists, with thousands of attendees each year, discussing allergies, asthma, and immune deficiency disorders.

Takhzyro® (lanadelumab-flyo)

  • Real-world Episodes of Long-term Prophylaxis for Hereditary Angioedema: A Descriptive Study Using Data From the Consortium of Independent Immunology Clinics
  • Longitudinal Study of Adult Patients With Hereditary Angioedema Receiving Long-term Prophylaxis for 3 Years or Longer With Lanadelumab: Baseline Findings
  • Understanding the Impact of Long-term Prophylaxis Switches for Patients With Hereditary Angioedema

Western Society of Allergy, Asthma and Immunology (WSAAI), 2025

February 9 - 13, 2025

Annual scientific session uniting allergists, immunologists, nurses, and physician assistants aimed at maintaining the highest standard of practice in allergy care.

Takhzyro® (lanadelumab-flyo)

  • Longitudinal Trend in Attack Outcomes in Patients With Hereditary Angioedema Receiving Long-term Prophylaxis With Lanadelumab: An Observational Study
  • Understanding the Impact of Long-term Prophylaxis Treatment Switches on Hereditary Angioedema Attack Characteristics

Cuvitru®[Immune Globulin Subcutaneous (Human)] 20% Solution

  • Clinical characteristics, treatment patterns, and healthcare resource utilization (HCRU) of patients with primary immunodeficiency diseases receiving immunoglobulin subcutaneous (human), 20% solution (Cuvitru) in a large US payer database

International Congress on Neuromuscular Diseases (ICNMD), 2024

October 25 - 29, 2024

This international congress offers attendees an updated view on neuromuscular disorders and networking opportunities to increase their international experience and collaborations.

American College of Allergy, Asthma & Immunology (ACAAI), 2024

October 24 - 28, 2024

Global meeting featuring thought leaders from around the world focused on advancing patient care in allergy and immunology.

Takhzyro® (lanadelumab-flyo)

  • Longitudinal Survey of Adult Patients with Hereditary Angioedema Receiving Long-Term Prophylaxis with Lanadelumab
  • Social Determinants of Health in Hereditary Angioedema and their Impact on Patient Outcomes

Immunoglobulin National Society (IgNS), 2024

October 17 - 20, 2024

National conference of IgNS bringing together professionals and practitioners from all disciplines and clinical specialties to advance Ig therapy practice, while providing networking and comprehensive education opportunities.

  • Real-World Characteristics and Disease Management for a Virtual Longitudinal Cohort of Patients with Chronic Inflammatory Demyelinating Polyneuropathy

The European Society for Immunodeficiencies (ESID), 2024

October 16 - 19, 2024

Biennial meeting that covers the latest discoveries in basic and clinical science covering our expanding field, bringing together internationally renowned scientists and clinicians to present and discuss major developments in diagnosis, clinical management, genetics, and immunobiology of inborn errors of immunity.

  • Cost-Effectiveness Of Next-Generation Sequencing Testing In Patients Eligible For Primary Immunodeficiency Screening In The United States

American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM), 2024

October 15 - 18, 2024

Annual meeting dedicated to the advancement of neuromuscular, musculoskeletal, and electrodiagnostic medicine.

  • Disease Severity and Healthcare Resource Utilization for Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Multifocal Motor Neuropathy: Results from an Integrated Database

Academy of Managed Care Pharmacy Nexus (AMCP Nexus), 2024

October 14 - 17, 2024

Annual event with more than 2,500 members and non-members of the AMCP to engage on the latest innovations and most intentional networking in managed care pharmacy.

Glassia® [Alpha1- Proteinase Inhibitor (Human)]

  • Demographics and Healthcare Resource Utilization in Patients in the United States with Alpha-1 Antitrypsin Deficiency who are Treated with Glassia (Alpha-1 Proteinase Inhibitor)

Additional Resources

Find materials to help foster a deeper understanding of Multifocal Motor Neuropathy (MMN).

Diagnosis of MMN Fact Sheet

An overview of Multifocal Motor Neuropathy (MMN) clinical presentation and diagnostic considerations.

Guideline Recommendations on the Diagnosis of MMN Fact Sheet

An overview of the task force guideline recommendations for diagnosing Multifocal Motor Neuropathy (MMN).

Medications

This resource provides information on Takeda medications available in the Multifocal Motor Neuropathy category and is not intended to represent a complete list of therapeutic options.

Gammagard Liquid®

[Immune Globulin Infusion (Human)] 10%

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