HWN Suggests

The Potential Misdiagnosis of Multifocal Motor Neuropathy as Amyotrophic Lateral Sclerosis

Recognizing the significant overlap in the presentation of MMN and ALS is particularly important given that MMN is treatable, whereas ALS is rapidly fatal and non-treatable. The profound psychosocial impact of an ALS diagnosis is well established and includes grief, depression, anxiety, feelings of hopelessness and other negative, life-altering psychological effects. While MMN can be debilitating, it does not carry the same grave prognosis as ALS and offers the hope of treatment options.

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  Know MMN

Experiencing weakness that started in a hand or foot on one side of your body? It might be a rare disease called MMN.

 Diagnosed With Multifocal Motor Neuropathy (MMN)?

If you receive IVIg every 2-5 weeks to control your Multifocal Motor Neuropathy (MMN), you may be able to participate in a study for MMN*

Articles of Interest

What is Multifocal motor neuropathy (MMN) or MMNCB

MMN is thought to be due to an abnormal immune response, but the underlying cause is not clear. Most people treated with intravenous immune globulin (IVIG) have rapid improvement in weakness, but maintenance IVIG is usually required for sustained improvement.

What is Multifocal Motor Neuropathy?

MMN is a rare nerve disorder with symptoms that are somewhat similar to those of other neuropathies that can impact the limbs. For example, muscle weakness, spasms, and cramping often associated with MMN also are seen in individuals with amyotrophic lateral sclerosis (ALS). Unlike MMN, ALS is rapidly progressive, and causes respiratory muscle weakness. In other people, MMN may be confused with nerve compression conditions including carpal tunnel syndrome.

Resources

ARDA

Find out about a new clinical study in MMN and if you are eligible to participate.

Gammagard

GAMMAGARD LIQUID is indicated as replacement therapy for primary humoral immunodeficiency (PI) in adult and pediatric patients ≥2 years and as a maintenance therapy to improve muscle strength and disability in adult patients with Multifocal Motor Neuropathy (MMN).

Foundation for Peripheral Neuropathy.

With very rare exceptions, MMN does not shorten life, or cause major problems with breathing or swallowing. However, it can cause a great deal of dysfunction and disability and the disorder appears to persist indefinitely and rarely goes into a long-term remission. The disorder is sometimes mistaken for amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease) but unlike ALS, it is treatable. An early and accurate diagnosis allows patients to recover quickly.

Multifocal Motor Neuropathy Awareness

FB site.

Neuropathy Action Foundation

The diagnosis of MMN depends on demonstrating that a patient has a purely motor disorder affecting individual nerves, that there are no UMN signs, that there are no sensory deficits, and that there is evidence of conduction block. These criteria are designed to differentiate the disorder from ALS (purely motor but with UMN signs), the Lewis-Sumner Syndrome variant of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) (similar to MMN but usually with significant sensory loss), and “vasculitis” (a type of multiple mononeuropathy syndrome caused by inflammatory damage to the blood vessels in nerves that also causes sensory and motor symptoms).

PolyNeuro Exchange

MMN is a rare, chronic, progressive neuropathy characterized by muscle weakness in the distal limbs, but minimal or no sensory changes. It is usually asymmetric, with different muscles involved on one side of the body versus the other. MMN is sometimes mistaken for amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease) but unlike ALS, MMN is treatable. A careful nerve conduction study can help lead to an accurate diagnosis.

GBS | CIDP

MMN is associated with increased levels of specific antibodies to GM1, a ganglioside or sugar-containing lipid found in peripheral nerve. Antibodies normally protect individuals from viruses and bacteria, but may under certain circumstances bind to and facilitate an immune attack on the peripheral nerve. These antibodies have been detected with newer assays in almost all of MMN patients. Even if these antibodies do not cause the nerve damage, they may be an important marker for disease and facilitate diagnosis.

NINDS

The disorder is sometimes mistaken for amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease. But unlike ALS, multifocal motor neuropathy is treatable. An early and accurate diagnosis allows individuals to recover quickly.

Physiopedia

Multifocal motor neuropathy (MMN) is a rare disorder that predominantly causes weakness in the distal limbs. The disorder is purely a motor neuropathy that presents asymmetrically and progresses slowly. An electrophysiological characteristic that distinguishes MMN from a motor neuron disease is a conduction block. Axon death occurs due to the lack of conduction which can lead to an entire nerve being affected. The nerves that are typically affected are peripheral nerves and more commonly the radial, ulnar, median and tibial nerves, however; MMN can affect other nerves as well. Since its symptoms are similar to that of Chronic Inflammatory Demyelinating Polyradiculoneuropathy in that they both occur due to a conduction block, it has been said that MMN is likely an immune-mediated neuropathy

StatPearls

Multifocal motor neuropathy (MMN), also called multifocal motor neuropathy with conduction block (MMNCB), is a rare, acquired, motor neuropathy characterized by progressive asymmetric weakness without sensory problems. It typically involves upper limbs more than the lower limbs.