Multifocal Motor Neuropathy

Not an actual patient.

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

  1. Genetic and Rare Disease Information Center. NIH — Multifocal motor neuropathy. https://rarediseases.info.nih.gov/diseases/11011/multifocal-motor-neuropathy. Accessed February 1, 2023. 
  2. Zivkovic S and Lorenzo N. Multifocal Motor Neuropathy With Conduction Blocks. Medscape. https://emedicine.medscape.com/article/1174021-overview. Accessed February 1, 2023.
  3. Vlam L, van der Pol WL, Cats EA, et al. Nat Rev Neurol. 2012;8(1):48-58. 
  4. Meuth SG and Kleinschnitz C. Eur Neurol. 2010;63(4):193-204. 
  5. Olney RK, Lewis RA, Putnam TD, et al. Muscle Nerve. 2003;27(1):117-121.
  6. Cats E, van der Pol WL, Piepers S, et al. Neurology. 2010;75(9):818-825.
  7. Van den Berg-Vos RM, Franssen H, Visser J, et al. J Neurol. 2001;249(3):330-336.
  8. Katirji B and Koontz D. Disorders of Peripheral Nerves. In: Neurology in Clinical Practice. Elsevier; 2012:1915-2015. 
  9. Nobile-Orazio E, Cappellari A, Priori A. Muscle Nerve. 2005;31(6):663-680. 
  10. International Alliance of ALS/MND Associations. What is ALS/MND? Published 2022. https://www.als-mnd.org/what-is-alsmnd/. Accessed February 1, 2023.
  11. Lawson VH and Arnold WD. Neuropsychiatr Dis Treat. 2014;10:567-576.
  12. Köller H, Kieseier B, Jander S, et al. N Engl J Med. Published online 2005:14.
  13. NIH. NINDS — Peripheral Neuropathy Fact Sheet. https://www.ninds.nih.gov/peripheral-neuropathy-fact-sheet. Accessed February 1, 2023. 
  14. van Schaik I, van den Berg LH, de Haan R, et al. Cochrane Database Syst Rev. 2005;(2).
  15. Hahn AF, Beydoun SR, Lawson V, et al. J Peripher Nerv Syst. 2013;18(4):321-330.

Upcoming & Past Conferences in Allergy & Immunology

  • Upcoming

  • Past

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

February 9 - 13, 2025 | Link to Event

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

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

February 28 - March 3, 2025 | 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), 2025

April 5 - 9, 2025 | Link to Event

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

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)

Southern California Allergy Conference (SCAC), 2024

October 13 - 13, 2024

Annual congress for members of the allergy and immunology community, with a focus on HAE and PID in 2024.

Takhzyro® (lanadelumab-flyo)

  • Lanadelumab Effectiveness and Safety by Disease Activity: EMPOWER/ENABLE Pooled Analysis
  • Understanding treatment switching patterns and continuation rates for patients with hereditary angioedema receiving lanadelumab: analysis of real-world data

American College of Chest Physicians (CHEST), 2024

October 6 - 9, 2024

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.

Neuromuscular Study Group (NMSG), 2024

September 20 - 22, 2024

Annual conference aiming to advance knowledge about the cause(s), pathogenesis, epidemiology, and clinical manifestations of muscle disease and related neuromuscular disorders and to develop and implement strategies to examine promising therapeutic interventions.

  • A Quantitative Study on the Patient Journey and Experience in Patients with CIDP and MMN
  • Plasma Proteomics and Autoantibody Screening: a Tool for Patient Stratification and Monitoring CIDP Treatment Responses

Consortium of Independent Immunology Clinics (CIIC), 2024

September 13 - 14, 2024

Semi-annual conference of key opinion leaders in the Allergy, Asthma, and Immunology space.

Takhzyro® (lanadelumab-flyo)

  • Understanding treatment switching patterns and continuation rates for patients with hereditary angioedema receiving lanadelumab: analysis of real-world data

Bradykinin Symposium

September 5 - 6, 2024

International experts in the field of bradykinin discuss the genetic, molecular, and cellular drivers of angioedema.

  • Comorbid Conditions in Patients With Hereditary Angioedema: Icatibant Outcome Survey

American Association of Nurse Practitioners (AANP), 2024

June 25 - 30, 2024

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

Peripheral Nerve Society (PNS), 2024

June 22 - 25, 2024

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

  • A Quantitative Study on The Patient Journey and Experience in Patients with CIDP and MMN

HyQvia® (Human Immune Globulin 10% with Recombinant Human Hyaluronidase)

  • Hyaluronidase-Facilitated Subcutaneous Immunoglobulin 10% For Chronic Inflammatory Demyelinating Polyradiculoneuropathy: Final Results from a Long-Term Safety and Tolerability Study

Association of Pulmonary Advanced Practice Providers (APAPP), 2024

June 20 - 22, 2024

The Association of Pulmonary Advanced Practice Providers (APAPP) is the first association to focus solely on advanced practice providers (APPs) working in the realm of pulmonary medicine. Join over 200 nurse practitioners and physician associates for in-depth reviews and discussions highlighting the latest developments and current concepts in pulmonary, critical care, and sleep medicine.

  • Overcoming Racial and Ethnic Biases in The Diagnosis of Patients with Alpha-1 Antitrypsin Deficiency in The United States Using a Machine-Learning Model

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

May 31 - June 3, 2024

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

Eastern Allergy Conference (EAC), 2024

May 30 - June 2, 2024

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

American Thoracic Society (ATS), 2024

May 17 - 22, 2024

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

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

May 5 - 8, 2024

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

Clinical Immunology Society (CIS), 2024

May 1 - 4, 2024

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.

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.

Takhzyro® (lanadelumab-flyo)

  • Comparison of Real-World Healthcare Resource Utilization and Costs Among Patients With Hereditary Angioedema on Lanadelumab or Berotralstat Long-Term Prophylaxis

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.

HyQvia® (Human Immune Globulin 10% with Recombinant Human Hyaluronidase)

  • Infusion-related Costs for HyQvia Compared to Hizentra in Chronic Inflammatory Demyelinating Polyradiculoneuropathy
  • Patient-reported outcomes with hyaluronidase-facilitated subcutaneous immunoglobulin 10% maintenance therapy for chronic inflammatory demyelinating polyradiculoneuropathy

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
  • Real-World Treatment Outcomes of Lanadelumab in the Prevention of Hereditary Angioedema Attacks: An Interim Analysis of a Polish Prospective, Multicenter, Observational Study (CHOPIN)
  • Real-World Treatment Patterns and Characteristics of Patients With Hereditary Angioedema Treated With Lanadelumab: Results From a US Retrospective Chart Review Study
  • Long-Term Effectiveness and Safety of Lanadelumab in Patients With Hereditary Angioedema From the United States and Canada: Final Data From the EMPOWER Study
  • Burden of Illness in Adult Patients With Controlled and Poorly Controlled Hereditary Angioedema: Findings From a Multinational Survey
  • Burden of Illness in Female and Male Adult Patients With Hereditary Angioedema: Findings From a Multinational Survey and the HELP OLE Study
  • Lanadelumab Effectiveness and Safety in Adolescent Patients With Hereditary Angioedema Aged 12 to <18 Years: Pooled Results From the Real-World ENABLE and EMPOWER Studies

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

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)]