Multifocal motor neuropathy is a progressively worsening nerve disease that affects the nerves to the muscles and thus causes weakness and cramping in muscles. The muscles can also have twitching and wasting. Different muscles can be affected in each of the limbs. This disorder is believed to be an autoimmune-based process.
Men are more often affected with multifocal motor neuropathy than women. Symptoms usually appear before age 45.
The disorder is sometimes mistaken for amyotrophic laterial sclerosis (ALS, or Lou Gehrig's disease), but unlike ALS, it is treatable. Nevertheless, definitive diagnosis is often difficult, and many MMN patients labor for months or years under an ALS diagnosis before finally getting a determination of MMN.
An early and accurate diagnosis allows patients to recover quickly.
Treatment for multifocal motor neuropathy varies. Some individuals experience only mild, modest symptoms and require no treatment. For others, treatment generally consists of intravenous immunoglobulin or immunosuppressive therapy.
While MMN usually involves no pain (except for muscle cramps) and is rarely fatal, it can lead to significant disability, with loss of function in hands affecting ability to work and perform everyday tasks, and foot drop leading to inability to stand and walk. Many of those affected end up using aids like canes and walkers.