ABC Medical Center > Diseases > Neuromyotonia

What is neuromyotonia?

12 December 2025

This is a low-incidence, autoimmune neurological condition that causes continuous neuromuscular spasms, even during sleep, which are difficult to control, primarily affecting the arms and legs.

Neuromyotonia, also called Isaacs’ syndrome, continuous muscle fiber activity syndrome, or continuous motor activity syndrome, typically appears between the ages of 20 and 65 with abnormal impulses in the nerve cells outside the brain and spinal cord that are responsible for controlling muscle movement. It occurs when immune system agents that fight cancer also attack parts of the brain, spinal cord, muscles, or peripheral nerves.

The cause of neuromyotonia is currently unknown, but clinical research points to hereditary factors and the presence of certain types of cancer as possible culprits, in addition to connective tissue disorders, Hashimoto’s disease, and vitamin B12 deficiency.

Signs and symptoms Neuromyotonia

The symptoms often worsen over time and include:

  • Alterations in heart rate.
  • Episodes of cramps.
  • Muscle contractures.
  • Muscle weakness.
  • Swallowing problems (dysphagia).
  • Digestive disorders.
  • Spasms.
  • Slow movements.
  • Respiratory problems.
  • Progressive stiffness.
  • Sweating.
  • Speech disorders.
  • Elevated temperature.

Diagnosis and treatment Neuromyotonia

The specialist will analyze the symptoms and clinical history, then perform a physical examination and order tests to help confirm the diagnosis, such as:

  • Laboratory tests.
  • Magnetic resonance imaging (MRI).
  • Computed tomography (CT scan).

Currently, there is no cure for neuromyotonia. Therefore, treatment focuses on controlling the symptoms to improve the person’s quality of life, using:

  • Stabilizing drugs.
  • Oral corticosteroids.
  • Non-steroidal immunosuppressants.
  • In more severe cases, intravenous immunoglobulin administration or plasma exchange (plasmapheresis) may be required.

At the Neurology Center, a group of highly trained and certified doctors in various neurological specialties are ready to assist you with the quality and warmth that characterizes us.

Related centers and departments Neuromyotonia

Neurology Center
High Specialty Surgery Center
Radiology and Molecular Imaging
Clinical Laboratory

Fuentes:

  • neurologia.com
  • neurology.org
  • orpha.net
  • elsevier.es
  • cun.es
  • nih.gov
  • mayoclinic.org
  • medigraphic.com
  • Gómez-Fernández L, Maragoto-Rizo C, Jiménez-Gil FJ. Síndromes de actividad continua de las fibras musculares originados en el sistema nervioso. Rev Mex Neurociencias. 2013;14(6):349-355.

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