Dear Venugopalan,

To my knowledge all criteria should be satisfied to diagnose the Stiff Person Syndrome (formerly known as the Stiff Man Syndrome). These criteria have been satisfied in the three patients I had to deal with and I believe are common to all patients with SPS.

Currently accepted clinical criteria for the diagnosis of stiff-person syndrome :

(1) insidious onset of muscular rigidity with difficulty turning or bending, with rigidity most prominent in the limbs and axial muscles, especially abdominal and thoracolumbar;

(2) co-contraction of agonist and antagonist muscles, confirmed clinically and electrophysiologically;

(3) episodic spasms superimposed on the underlying rigidity, precipitated by noise, tactile stimuli, or emotional upset;

(4) absence of other neurologic or other diseases that could explain the symptoms

May be you can use this paper:

http://www.ncbi.nlm.nih.gov/pubmed/10507962

Hoping to have been of any help,

Best Regards,

Ilir Alimehmeti