Multifocal Motor Neuropathy (MMN)

Understanding Multifocal Motor Neuropathy (MMN)

Multifocal Motor Neuropathy (MMN) is a rare, chronic autoimmune neurological disorder that primarily affects the motor nerves, resulting in progressive muscle weakness. Unlike many other neuropathies, MMN does not typically cause sensory loss or pain. Instead, it leads to asymmetric weakness, most often impacting the hands and arms. The disorder is caused by the immune system mistakenly attacking the motor nerves, creating nerve conduction blocks that hinder normal muscle movement. Although MMN is sometimes misdiagnosed as amyotrophic lateral sclerosis (ALS), it is a treatable condition.

Common Signs and Symptoms of MMN:

• Asymmetric Muscle Weakness: Gradual and uneven loss of strength, particularly in the hands and arms.
• Difficulty with Fine Motor Skills: Challenges with tasks such as writing, buttoning clothing, or handling small objects.
• Muscle Atrophy: Over time, the affected muscles may shrink due to disuse.
• Clumsiness: Increased tendency to drop objects or struggle with coordinated movements.
• Preserved Sensation: Typically, there is little to no sensory loss or pain associated with the condition.

This information is provided as a resource and is not intended to diagnose a condition or prescribe treatment. Please discuss any symptoms you may exhibit with your physician.