Stiff Man syndrome
What are the symptoms?
This condition is characterised by progressive stiffness and painful spasms in the back and lower limbs which are often triggered by touch, noise or anxiety. The unpredictable onset and nature of the symptoms associated with SMS may be experienced as frightening. Where the limbs are predominately involved, the condition is also known as Stiff Limb syndrome.
This is a progressive condition, and stiffness may increase to the extent that the individual becomes a wheelchair user. Both the rigidity and the frequency of spasms may be relieved by sleep, general anaesthesia, nerve block and peripheral nerve block. About forty per cent of individuals also have Type 1 diabetes (see entry, Diabetes Mellitus) which is an autoimmune disease.
Three types of Stiff Man syndrome have been described:
Some individuals with Stiff Man syndrome/Stiff Limb syndrome show an immune response to an enzyme called glutamic acid decarboxylase (GAD). Individuals with classic Type 1 Diabetes show a similar immune response. GAD is an important enzyme in the formation of a chemical messenger in the brain and spinal cord and also in the transmission of insulin. When a patient is developing SMS or Type 1 Diabetes, antibodies to GAD are produced which leads to its destruction, thus interrupting transmission.
Background
| How is it diagnosed? ![]()