Multifocal Motor Neuropathy (MMN)

Multifocal motor neuropathy (MMN) is a rare chronic disorder in which the immune system attacks specific motor nerves, causing slow progressive weakness without significant sensory loss. It is often confused with ALS but responds well to immune therapy.

Table of Contents

Quick Facts

  • ICD-10: G61.81
  • Treatment: IVIG

Symptoms

  • Slowly progressive asymmetric weakness, often starting in the hands
  • Muscle cramping and twitching
  • Normal sensation
  • Specific nerve distributions (not whole limbs)

Diagnosis

  • Nerve conduction studies showing characteristic conduction blocks
  • Anti-GM1 antibodies in some patients
  • Distinguish from ALS (no upper motor neuron signs, no sensory involvement)

Treatment

  • Intravenous immunoglobulin (IVIG) — mainstay
  • Subcutaneous immunoglobulin as alternative
  • Immunosuppressants in selected cases

Related Conditions

Peripheral Neuropathy

Different neuropathy

 Guillain-Barre Syndrome

Different immune neuropathy
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. If you are experiencing a medical emergency, call your local emergency number immediately.

References

  • GBS/CIDP Foundation International. Patient Resources.