Stiff person syndrome is a very rare (affecting only 1 in 1,000,000) neurological disorder causing progressive stiffness and rigidity in the muscles of the torso and upper legs. The disease usually starts in the 40’s and is characterized by muscle spams primarily affecting the abdominal and lower back muscles and the condition gradually worsens over lifetime . These spasms often cause a condition called hyperlordosis which is when the lower back is pushed far more forward than normal, illustrated by the above picture. Additionally, the condition can include the hips, shoulder, arms and face. Symptoms can be exacerbated by stress, infection and cold weather, and sleep often decreases them.
Stiff person syndrome affects women twice as much as it does men and has an autoimmune as well as genetic basis. a majority of SPS patients have large amounts of antibodies against glutamate decarboxylase or GAD. Many people with SPS also have type 1 diabetes, as well as the DQB1* 0201 allele, a gene shared by those with SPS and diabetes.
SPS was described first in 1956 by Moersch and Woltman based on only 14 cases they had observed over three decades. The disease had previously been thought to be a psychogenic problem. Treatment includes benzodiazepines, corticosteroids, immunoglobulin and plasma exchange.