Rigid Man Syndrome

Rigid man syndrome is a rare autoimmune movement disorder affecting the central nervous system (brain and spinal cord). Most often, the disease begins with a feeling of stiffness in the lumbar spine and limbs, painful muscle spasms that occur spontaneously or are provoked by a loud sound, emotional stress or physical touch.

The syndrome of a rigid person is extremely rare. The prevalence is estimated at about 1:1,000,000. It is more common in women. Symptoms can occur at any age, but usually develop between the ages of 30 and 60.

Often the syndrome of a rigid person is associated with other autoimmune diseases: diabetes mellitus, autoimmune thyroiditis, vitiligo and pernicious anemia. It can also be associated with some types of cancer, including breast, lung, kidney, thyroid, colon, and Hodgkin's lymphoma.

Mechanisms of disease development

Rigid man syndrome is an autoimmune disease, that is, a condition in which the body's immune system attacks healthy cells. Most patients with rigid man syndrome produce antibodies that attack the enzyme glutamic acid decarboxylase (anti-GAD antibodies). This enzyme is necessary for the synthesis of inhibitory neurotransmitter - gamma-aminobutyric acid (GABA). One of the functions of GABA is to control muscle movement. It is believed that the immune system of patients with rigid man syndrome mistakenly attacks the GAD enzyme, resulting in a decrease in the amount of GABA, which leads to the main complaints of stiffness and painful muscle spasms.

In rare cases, antibodies to another protein, amphiphysin, are detected. This protein is found in nerve synapses and provides communication between neurons. Also, anti-GlyR, anti-DPPX, anti-GABAa, anti-Gephyrin antibodies can be associated with rigid man syndrome.


Usually, the symptoms of the disease develop over several months or years. In most patients, the first complaints are painful spasms, stiffness of the muscles of the back and limbs.

Initially, stiffness may have a periodic character, but over time it becomes permanent. As stiffness increased, some people developed a slouch.

Painful muscle spasms can last for several seconds, minutes, and sometimes several hours. Cramps can occur for no reason or be caused by an unexpected loud sound, physical touch, cold, or emotional stress. Muscle spasms can be felt throughout the body or only in a certain area.

A positive effect in the form of a decrease in the number of spasms is provided by sleeping and taking certain medications.

It is worth noting that some patients with anti-GAD antibodies may have additional clinical manifestations in the form of epileptic seizures, cerebellar ataxia (impaired coordination of movements), limbic encephalitis (impaired memory, consciousness, signs of mental disorder and epilepsy), myoclonus (short-term muscle contraction) and impaired eye movement.

Diagnostic methods

Based on complaints, medical history and neurological examination, the neurologist determines the indications for the following diagnostic tests that are necessary to confirm the diagnosis:

  • Blood test. Anti-GAD and antibodies to amphiphysin are examined in the blood. In 60-80% of patients with rigid man syndrome, high titers of anti-GAD antibodies are determined.
  • Needle electromyography (iEMG). An invasive research method that uses a needle electrode to assess the electrical activity of muscles at rest and under stress. With the syndrome of a rigid person, constant motor activity of muscle units is recorded.
  • Lumbar puncture (spinal puncture). During the puncture, cerebrospinal fluid (cerebrospinal fluid) is taken from the spinal canal to check for anti-GAD antibodies, as well as to evaluate other parameters for differential diagnosis.

Treatment options

The goal of therapy is to relieve symptoms and improve quality of life. There are two main areas of therapy for rigid man syndrome: symptomatic and pathogenetic.

Symptomatic therapy includes drugs from the group of benzodiazepines, centrally acting muscle relaxants, anticonvulsants, which are prescribed to reduce muscle stiffness and painful spasms.

  Pathogenetic therapy is aimed at reducing the negative effects of autoantibodies. Treatment options include high-dose intravenous immunoglobulin (IVIG), plasmapheresis, rituximab, and tacrolimus. Therapy should be prescribed and adjusted individually for each patient, depending on the symptoms and severity of the condition.

To consult a neurologist, conduct electromyography and prescribe therapy, you can contact the Center of Neuromuscular Pathology MCSC named after A.S. Loginov.

Conducting a comprehensive examination and receiving pathogenetic treatment is possible during hospitalization in the neurological department of the MCSC named after A.S. Loginov.

Make an appointment for a consultation at the Central Medical Center : +7 (495) 304-30-39

GBUZ Moscow Clinical Scientific Center named after Loginov MHD