Stiff Person Syndrome with Pyramidal Signs.

Stiff person syndrome (SPS) is a rare disorder characterized by continuous muscle activity causing severe rigidity and episodic spasms in axial and limb muscles (1). According to the diagnostic criteria, normal motor and sensory examination is the rule. Hyperactive deep tendon reflexes may be observed, but extensor plantar reflexes are rare (1,2,3,4). Here, by presenting this case with atypical features like pyramidal signs, we aimed to review the clinical and electrophysiological signs of this rare syndrome.