Stiff Man Syndrome

Stiff Man Syndrome

Stiff man syndrome is a neurological disorder that causes severe muscle stiffness and painful spasms. This condition is typically characterized by autoantibodies against the enzyme glutamic acid decarboxylase, which can be detected in the serum of patients with this condition. Many patients also have systemic autoimmune diseases, such as diabetes mellitus. Therefore, the stiff-man syndrome may be an autoimmune disorder.

Stiff-limb variant

The stiff-limb variant of the stiff-man syndrome has been considered a separate disorder from the more common stiff-man syndrome. It is characterized by muscle rigidity and spasm. It is a progressive form of encephalomyelitis. There are a variety of causes for this syndrome.

This neurological disorder is characterized by progressive limb rigidity accompanied by painful spasms. The disease is usually insidious in onset and becomes increasingly severe over time. Eventually, it can lead to permanent disability and mortality.

Autoimmune form of stiff-person syndrome

Stiff Person Syndrome (SPS) is a rare autoimmune movement disorder that affects the central nervous system. Its symptoms include muscle stiffness, spasm, and increased response to startling. There are three recognized forms of SPS: the autoimmune form, which affects approximately 60% of sufferers, and the non-autoimmune form, which affects less than 1% of sufferers. In the autoimmune condition, antibodies to glutamic acid decarboxylase and amphiphysin are present. The two proteins target motor neurons and interneurons in the spinal cord.

Stiff person syndrome is a progressive neurological disorder with symptoms that may appear suddenly or last for many years. It occurs due to the body's immune system attacking healthy cells. The disease begins in the trunk muscles but can eventually affect any body part. This disorder is often accompanied by pain and can be triggered by noise or emotional stress.


Stiff man syndrome is a rare neurological condition characterized by muscle stiffness and painful spasms. It is usually associated with 70% serum autoantibodies to glutamic acid decarboxylase. In addition, patients with this condition often have other underlying autoimmune disorders, such as insulin-dependent diabetes mellitus.

Stiffness and spasms may be predominant symptoms of some neurological diseases. Examples include:

  • Multiple sclerosis.
  • Spinal cord and brain stem tumours.
  • Paraneoplastic diseases.
  • Circulatory diseases of the spinal cord.

A careful clinical and neurophysiological examination is required to differentiate SMS from other causes of limb stiffness. In addition, an MRI of the brain and spinal cord may be needed to confirm the diagnosis.


Treatment for the stiff-man syndrome is usually based on its underlying cause. The disorder is characterized by paraspinal rigidity, abdominal rigidity, lumbar hyperlordosis, and spasms. In addition, the disease is characterized by a normal sensory examination and motor unit activity. The stiffness is most often in the lower extremities but can also involve the calf and foot muscles. Seizures are not common.

Stiff person syndrome is a neurological disorder caused by circulating antibodies against glutamic acid decarboxylase (GAD), which is responsible for synthesizing g-aminobutyric acid. These reduced GABA levels may account for stiffness and unexpected spasms in patients with the disorder.