What is stiff person syndrome?

Answer:
Stiff person syndrome (SPS) is an extremely rare progressive neurological disorder characterized by persistent rigidity and spasms of certain voluntary muscles, especially those of legs and feet.
First answer by Gale Ency of Neuro Dis. Last edit by Gale Ency of Neuro Dis. Contributor trust: 14 [recommend contributor recommended]. Question popularity: 2 [recommend question].