Symptoms
Muscle stiffness is the most common symptom of stiff person syndrome. In the early stage, patients might have limb stiffness, trunk stiffness, posture issues due to rigid back muscles, excessive sweating, sensory problems, walking issues, and painful muscle spasms. Spasms caused by stiff person syndrome can be extremely strong and could lead to a sudden fall. In some cases, the force may be so strong that it can break bones. Symptoms tend to become worse when you are upset or anxious. Other possible triggers include loud noises, sudden touches, or unexpected movements. Physical signs can also cause mental problems in people with the disorder. A decrease in brain neurotransmitters can trigger anxiety or depression.
Muscle stiffness could spread to other body parts, especially the face. The condition can also increase the risk for some forms of cancer as amphiphysin antibodies are produced. These include lung cancer, colon cancer, and breast cancer. Some cases might develop other autoimmune conditions, including vitiligo, pernicious anemia, thyroid issues, and diabetes. [3]
