This condition is characterised by progressive stiffness and painful spasms in the back and limbs, which are often triggered by touch, noise or anxiety, and exacerbated by movement.
This is a progressive condition, but only exceptionally does stiffness increase to the extent that the person will require use of a wheelchair.
About 40% of individuals also have type 1 diabetes (see entry Diabetes Mellitus).
Three types of stiff person syndrome have been described:
- classical person man syndrome - painful spasms and rigidity occur around the back, stomach and sometimes thighs and neck. As the condition progresses, curvature of the lower back can occur. Classical stiff person syndrome is commonly associated with type 1 diabetes
- stiff limb syndrome - the legs, including the feet, are affected by painful spasms and occasionally fixed rigidity. More rarely, the hands can be affected
- jerking stiff person syndrome - otherwise known as progressive encephalomyelitis with rigidity - is the rarest form of SPS. It is a more aggressive form of SPS, which involves many of the above symptoms but also may affect the control of the muscles of the head and eyes. It can lead to progressive disability over a number of months or years.