Need info about stiff persons syndrome please?

Stiff Man syndrome: Stiff person syndrome (sps) (or stiff-man syndrome; also known as moersch-woltman condition) is a rare neurologic disorder of unknown etiology characterized by progressive rigidity and stiffness, primarily of the axial musculature, that is superimposed by spasms, resulting in postural deformities. There are also sub-variants: stiff baby syndrome and stiff limb syndrome.