MMN is an immune-mediated demyelinating neuropathy that causes progressive, asymmetric weakness of the distal limbs with no objective sensory loss.1

Whom It Effects

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Differential Diagnosis

Learn more about diagnosis and treatment of MMN:

  • MMN has historically been difficult to diagnose due to its similarity to other related diseases including chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), Lou Gehrig's disease [amyotrophic lateral sclerosis (ALS)], lower motor neuron disease and Lewis-Sumner Syndrome2
  • MMN may also be misdiagnosed as nerve compression (entrapment neuropathy)2

Diagnostic criteria for MMNa

  • Asymmetric weakness of distal arm and/or leg muscles1,3,6,8 a
  • No objective sensory impairment3,8 a
  • Motor nerve conduction block in 2 or more nerves1,2,7,8,9 b
  • Axonal demyelination, damage and/or loss1,2,10
  • Anti-GM1 antibodies (present in over 50% of patients with MMN)1,9
  • Other tests that may be useful to confirm or exclude a diagnosis of MMN include MRI and CSF2

aMMN should be considered when patients present with asymmetric, distal muscle weakness with no objective sensory loss.

bEstablishing diagnosis based on consensus criteria for confirming conduction block may result in underdiagnosis, as conduction block is not always necessary for a diagnosis if other criteria are met

Not all patients exhibit all symptoms.


The importance of a timely diagnosis


In a retrospective case cohort analysis of 47 patients with MMN the mean symptoms duration prior to diagnosis was 6 years.
  • Mean time from symptom onset to diagnosis:
  • 6
  • YEARS
    (range:<1 to 23 years)6
  • Undiagnosed and unmanaged, MMN will progress as patients:
    • Experience spreading muscle weakness, making it more difficult to identify asymmetry3
    • Lose muscle mass due to atrophy3
  • MMN cannot be cured, and disease progression depends on how long patients remain undiagnosed.1,2
  • Axon loss is the most important determinant of permanent weakness and disability2
Prognosis is better with early diagnosis1,2

GAMMAGARD LIQUID is indicated as a maintenance therapy to improve muscle strength and disability in adult patients with Multifocal Motor Neuropathy (MMN).

WARNING: THROMBOSIS, RENAL DYSFUNCTION and ACUTE RENAL FAILURE

  • Thrombosis may occur with immune globulin products, including GAMMAGARD LIQUID. Risk factors may include advanced age, prolonged immobilization, hypercoagulable conditions, history of venous or arterial thrombosis, use of estrogens, indwelling vascular catheters, hyperviscosity, and cardiovascular risk factors. Thrombosis may occur in the absence of known risk factors.
  • Renal dysfunction, acute renal failure, osmotic nephrosis, and death may occur in predisposed patients with immune globulin intravenous (IGIV) products including GAMMAGARD LIQUID. Renal dysfunction and acute failure occur more commonly with IGIV products containing sucrose. GAMMAGARD LIQUID does not contain sucrose.
  • For patients at risk of thrombosis, administer GAMMAGARD LIQUID at the minimum dose and infusion rate practicable. Ensure adequate hydration in patients before administration. Monitor for signs and symptoms of thrombosis and assess blood viscosity in patients at risk of hyperviscosity.
  • GAMMAGARD LIQUID is contraindicated in patients who have a history of anaphylactic or severe systemic hypersensitivity reactions to the administration of human immune globulin. GAMMAGARD LIQUID is contraindicated in IgA-deficient patients with antibodies to IgA and a history of hypersensitivity.
  • HYPERSENSITIVITY: IgA deficient patients with antibodies to IgA are at greater risk of developing potentially severe hypersensitivity and anaphylactic reactions. In case of hypersensitivity, discontinue GAMMAGARD LIQUID infusion immediately and institute appropriate treatment.
  • RENAL DYSFUNCTION/FAILURE: Monitor renal function, including blood urea nitrogen, serum creatinine, and urine output in patients at risk of acute renal failure. Ensure that patients with pre-existing renal insufficiency are not volume depleted. For patients at risk for renal dysfunction or thrombotic events, administer GAMMAGARD LIQUID at the minimum infusion rate practicable.
  • Hyperproteinemia, increased serum viscosity, and hyponatremia may occur in patients receiving GAMMAGARD LIQUID.
  • THROMBOSIS: Thrombosis may occur following treatment with immune globulin products, including GAMMAGARD LIQUID. Monitor for signs and symptoms of thrombosis and assess blood viscosity in patients at risk for hyperviscosity.
  • Aseptic Meningitis Syndrome (AMS) may occur with IGIV treatment, and has been reported with intravenous (IV) use of GAMMAGARD LIQUID. AMS may occur more frequently with high dose (2 g/kg) IGIV treatment and/or rapid infusion of IGIV.
  • Hemolytic anemia can develop subsequent to GAMMAGARD LIQUID treatment due to enhanced RBC sequestration. Risk factors may include: high doses (e.g., ≥2 g/kg cumulative dose), non-O blood group, and underlying inflammation. Monitor patients for clinical signs and symptoms of hemolysis and delayed hemolytic anemia.
  • Transfusion-Related Acute Lung Injury (TRALI): Non-cardiogenic pulmonary edema has been reported in patients following treatment with IGIV products, including GAMMAGARD LIQUID. Monitor patients for pulmonary adverse reactions.
  • GAMMAGARD LIQUID is made from human blood. It may carry a risk of transmitting infectious agents, e.g., viruses, the variant Creutzfeldt-Jakob disease (vCJD) agent, and theoretically, the Creutzfeldt-Jakob disease agent. No confirmed cases of viral transmission or vCJD have been associated with GAMMAGARD LIQUID.
  • Passive transfer of antibodies may transiently impair the immune responses to live attenuated virus vaccines such as mumps, rubella, varicella, and measles. This passive transfer may also yield false positive serological testing results, with the potential for misleading interpretation.

The serious adverse reactions in the MMN (IV administration) clinical trial were pulmonary embolism and blurred vision. The most common adverse reactions observed in ≥ 5% of patients in the clinical trials were:

MMN (IV administration): Headache, chest discomfort, muscle spasms, muscular weakness, nausea, oropharyngeal pain, and pain in extremity.

Please see the accompanying full Prescribing Information, including Boxed Warning.

To report suspected adverse reactions, contact FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

To report suspected adverse reactions, contact Shire Drug Safety at 1-800-999-1785 or .

If you have a medical or clinical question regarding the use of GAMMAGARD LIQUID, please contact Shire Medical Information at 1-866-424-6724 or

References:

  1. Katirji B, Koontz D. Disorders of peripheral nerves. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice. Vol 2. 6th ed. Philadelphia, PA: Saunders Elsevier; 2012:1915-2015.
  2. Vlam L, van der Pol W-L, Cats EA, et al. Multifocal motor neuropathy: diagnosis, pathogenesis and treatment strategies. Nat Rev Neurol. 2012;8(1):48-58.
  3. Shy ME. Peripheral neuropathies. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:2396-2409.
  4. Bastos AF, Orsini M, Machado D, et al. Amyotrophic lateral sclerosis: one or multiple causes? Neurol Int. 2011:3(1);12-16.
  5. Olney RK, Lewis RA, Putnam TD, Campellone JV Jr. Consensus criteria for the diagnosis of multifocal motor neuropathy. Muscle Nerve. 2003;27(1):117-121.
  6. Slee M, Selvan A, Donaghy M. Multifocal motor neuropathy: the diagnostic spectrum and response to treatment. Neurology. 2007;69(17):1680-1687.
  7. Data on file, Baxter Healthcare Corporation. 2011.
  8. Van der Pol W-L, Cats EA, van den Berg LH. Intravenous immunoglobulin treatment in multifocal motor neuropathy.J Clin Immunol. 2010;30(suppl 1):S79-S83
  9. Van Schaik IN, Léger J-M, Nobile_Orazio E, et al. Multifocal motor neuropathy. In: Gilhus NE, Barnes MP, Brainin M, eds. European Handbook of Neurological Management: Volume 1. 2nd ed. West Sussex, England: Blackwell Publishing Ltd; 2011:343-350
  10. Van Asseldonk JTH, Van den Berg LH, Kalmijn S, et al. Axon loss is an important determinant of weakness in multifocal motor neuropathy. J Neurol Neurosurg Psychiatry. 2006;77(6):743-747
The largest
controlled clinical
trail in Multifocal
Motor Neuropathy
to date7
View Study Design