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

Epidemiology

In the U.S., the prevalence of MMN is approximately 1 to 2 per 100,000, 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

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 conduction block (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 ganglioside-monosialic acid (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

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 GM1 gangliosides
  • Complement protein recruitment
  • Membrane attack complex recruitment
  • Axonal damage

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

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

Upcoming & Past Conferences in Allergy & Immunology

  • Upcoming

  • Past

Clinical Immunology Society (CIS), 2024

May 1 - 4, 2024 | Link to Event

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.

Professional Society for Health Economics and Outcomes Research (ISPOR), 2024

May 5 - 8, 2024 | Link to Event

Leading global conference discussing how to establish, incentivize, and share value sustainable for health systems, patients, and technology developers.

American Thoracic Society (ATS), 2024

May 17 - 22, 2024 | Link to Event

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

Eastern Allergy Conference (EAC), 2024

May 30 - June 2, 2024 | Link to Event

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

European Academy of Allergy & Clinical Immunology (EAACI), 2024

May 31 - June 3, 2024 | Link to Event

The flagship meeting of the EAACI and the world’s largest congress specializing in the field of allergy and clinical immunology.

Peripheral Nerve Society (PNS), 2024

June 22 - 25, 2024 | Link to Event

The largest peripheral nerve meeting globally, offering the latest international research across specialties in peripheral neuropathy.

American Association of Nurse Practitioners (AANP), 2024

June 25 - 30, 2024 | Link to Event

A national conference offering exclusive continuing education, legislative policy updates, hands-on workshops, lively exhibitors, and networking opportunities for the nurse practitioner community.

Academy of Managed Care Pharmacy (AMCP), 2024

April 15 - 18, 2024

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

American Academy of Neurology (AAN), 2024

April 13 - 18, 2024

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

National Home Infusion Association (NHIA), 2024

March 23 - 27, 2024

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.

Hereditary Angioedema International (HAEi), 2024

March 15 - 17, 2024

Every second year HAEi gathers HAE patients, caregivers, healthcare professionals, and industry representatives with a sole focus of sharing experience and knowledge on HAE topics.

Annual Meeting American Academy of Allergy Asthma and Immunology (AAAAI), 2024

February 23 - 26, 2024

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

  • Patient-Reported Outcomes Among Patients With Hereditary Angioedema Within Underrepresented Racial or Ethnic Groups

Takhzyro® (lanadelumab-flyo)

  • Real-World Treatment Outcomes in Patients With Hereditary Angioedema Receiving Lanadelumab or Other Long-Term Prophylaxis
  • Understanding the Impact of Long-Term Prophylaxis Switches for Patients With Hereditary Angioedema

Western Society of Allergy, Asthma and Immunology (WSAAI), 2024

February 4 - 8, 2024

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

  • Understanding Social Determinants of Health and Outcomes in Patients With Hereditary Angioedema in the United States
  • Quality of Life Among Patients With Hereditary Angioedema Within Underrepresented Racial or Ethnic Groups

Takhzyro® (lanadelumab-flyo)

  • Real-World Quality of Life in Patients With HAE Receiving Lanadelumab or Other Long-Term Prophylaxis

American College of Allergy, Asthma & Immunology (ACAAI), 2023

November 9 - 13, 2023

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

  • Healthcare Experiences Prior to Hereditary Angioedema Diagnosis in Underrepresented Racial/Ethnic Groups in the United States
  • Perspectives of Medical Care Among Patients With Hereditary Angioedema Within Underrepresented Racial or Ethnic Groups

Takhzyro® (lanadelumab-flyo)

  • Real-World Outcomes in Patients With HAE Receiving Lanadelumab Long-Term Prophylaxis for 3 Years or Longer
  • Real-World Quality of Life in Patients With HAE Receiving Lanadelumab or Other Long-Term Prophylaxis

Academy of Managed Care Pharmacy Nexus (AMCP Nexus), 2023

October 16 - 19, 2023

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.

  • Healthcare Resource Use Among Individuals With Chronic Obstructive Pulmonary Disease With and Without Alpha-1 Antitrypsin Deficiency in a United States Medicare Advantage Population
  • Characteristics, Healthcare Resource Utilization, and Costs Among Patients With Multifocal Motor Neuropathy: a United States Claims Database Cohort Study

Takhzyro® (lanadelumab-flyo)

  • A Cost Model Comparing Long-Term Prophylaxis Options for Hereditary Angioedema: Lanadelumab and Berotralstat
  • Characteristics of Patients With Hereditary Angioedema on Long-Term Prophylaxis With Lanadelumab Who Did and Did Not Down-Titrate Lanadelumab During 18 Months of Treatment Persistence

ID Week, 2023

October 11 - 15, 2023

The joint annual meeting of leading global societies dedicated to infectious disease research and advances.

American College of Chest Physicians (CHEST), 2023

October 8 - 11, 2023

Annual meeting offering the most up-to-date education in pulmonary, sleep, and critical care medicine through simulation sessions and original research presentations with clinical relevance to practitioners.

Immunoglobulin National Society (IgNS), 2023

October 5 - 8, 2023

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.

Aspen Allergy Conference (AAC), 2023

July 30 - August 3, 2023

Annual conference that invites state-of-the-art speakers from around the world to discuss basic science and clinical topics on allergy, asthma, and immunology.

European Academy of Allergy & Clinical Immunology (EAACI), 2023

June 9 - 11, 2023

The flagship meeting of the EAACI and the world’s largest congress specializing in the field of allergy and clinical immunology.

Takhzyro® (lanadelumab-flyo)

  • Clinical Outcomes and Quality of Life in Patients With HAE Receiving Lanadelumab Long-Term Prophylaxis: Interim Analysis of 3-Year Real-World Data

American Society of Clinical Oncology (ASCO), 2023

June 2 - 6, 2023

Annual meeting providing a forum for oncology professionals, patient advocates, and industry representatives to learn about and discuss the important issues in cancer care across a variety of disease sites, treatment approaches, and disciplines.

Eastern Allergy Conference (EAC), 2023

June 1 - 4, 2023

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

American Thoracic Society (ATS), 2023

May 19 - 24, 2023

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

  • Machine-learning Model Identifies Patients With Alpha-1 Antitrypsin Deficiency (AATD): Expert Validation and Comparison of Journeys For Patients With AATD Versus Chronic Obstructive Pulmonary Disease
  • Machine-learning Model Identifies Patients With High Probability of Alpha-1 Antitrypsin Deficiency Across the United States
  • Survey of Diagnostic Journey, Treatment Experience, and Impact on Daily Living of Patients with Alpha-1 Antitrypsin Deficiency

Clinical Immunology Society (CIS), 2023

May 18 - 21, 2023

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.

  • Patterns of IgG Testing and Rates of Hypogammaglobulinemia in Patients With Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

Professional Society for Health Economics and Outcomes Research (ISPOR), 2023

May 7 - 10, 2023

Leading global conference discussing how to establish, incentivize, and share value sustainable for health systems, patients, and technology developers.

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).

Medication Resources

Gammagard Liquid®

[Immune Globulin Infusion(Human)]