Stiff Person Syndrome (SPS) is an autoimmune disorder of the nervous system.
According to health experts, it often results in progressive, severe muscle stiffness and spasms of the lower part of the body and back.
The online medical site Mayo Clinic says the condition more commonly affects women, usually starting in the 40s or 50s.
Johns Hopkins Medicine on the other hand notes that people who have stiff person syndrome can experience severe muscle spasms and other unpleasant symptoms that can worsen without treatment.
However, some people experience other symptoms such as an unsteady gait, double vision or slurred speech, it says.
