ABC Medical Center > Diseases > Stiff Person Syndrome

What is stiff person syndrome?

12 December 2025

It is an autoimmune neurological disease that affects the central nervous system, especially the cerebellum and spinal cord, causing muscle rigidity and spasms in the abdomen, trunk, arms, and legs, which leads to generalized disability.

Stiff person syndrome (SPS) occurs most frequently in women between 30 and 60 years of age. Clinical studies suggest that its onset may be due to an immune system reaction that mistakenly attacks nerve cells in the spinal cord that control muscle movement. However, the true cause is still unknown, but it is also linked to genetic factors and the presence of other conditions, such as:

  • Anemia.
  • Breast cancer.
  • Lung cancer.
  • Kidney cancer.
  • Colon cancer.
  • Type 1 diabetes.
  • Hodgkin’s lymphoma.
  • Thyroiditis.
  • Vitiligo.

It is important to mention that people with stiff person syndrome have antibodies that attack the enzyme glutamic acid decarboxylase (GAD), which is responsible for producing neurotransmitters that help prevent nerves from overstimulating muscles. When a lower amount of this enzyme is produced, the nerves overstimulate the muscles, causing them to become tense and rigid.

Signs and symptoms Stiff Person Syndrome

  • Epileptic seizures.
  • Difficulty walking or standing up.
  • Muscle rigidity.
  • Spasms.
  • Cerebral palsy (Note: this is often listed in relation to the resulting movement issues, though the conditions are distinct).
  • Abnormal postures.
  • Anxiety.
  • Depression.

Diagnosis and treatment Stiff Person Syndrome

After the specialist analyzes your symptoms and clinical history, they will perform a physical examination and request the following tests to confirm the diagnosis, including:

  • Electromyography (EMG).
  • Blood tests.
  • Lumbar puncture (spinal tap).

The treatment primarily focuses on alleviating the symptoms through:

  • Anticonvulsants.
  • Sedatives.
  • Muscle relaxants.
  • Corticosteroids.
  • Immunoglobulin (IVIg).
  • Plasmapheresis (plasma exchange).
  • Physical therapy.
  • Occupational therapy.

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

Related centers and departments Stiff Person Syndrome

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

Fuentes:

  • neurologia.com
  • neurology.org
  • elsevier.es
  • aarp.org
  • nih.gov
  • topdoctors.mx
  • msdmanuals.com
  • medigraphic.com
  • Gómez VN, Olivera LIR, Pardo NA, et al. Síndrome de la persona rígida. Rev cubana med. 2018;57(1):55-60.
  • Cabrera EES, Enríquez CG. Síndrome de la persona rígida. Caso clínico y revisión de la literatura. Rev Mex Neuroci. 2017;18(4):86-94.
  • Serra VMÁ, Milán GE, García VM, et al. El Síndrome del Hombre rígido o Síndrome de la persona rígida. Presentación de un caso. Revista Habanera de Ciencias Médicas. 2014;13(5):719-727.

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