Diagnosis of SPS was confirmed according to the criteria: a prodrome of episodic aching stiffness of axial muscles; progression to include stiffness of proximal limbs; painful spasms elicited by triggers; increased lumbar lordosis; normal sensation, motor function, and intellect; continuous motor-unit activity on electromyogram abolished by benzodiazepines; high-titer glutamic acid decarboxylase (GAD) antibodies.[7]. Here, GAD1 is linked to stiff-person syndrome.