Stiff-person syndrome (SPS) is an autoimmune disease classically characterized by progressive muscular stiffness and lower back pain with sudden episodes of muscular spasm and, in certain cases, dysautonomia.() In general, the disease is diagnosed based on the presence of high anti-glutamic acid decarboxylase (anti-GAD) antibody titers both in the serum and cerebrospinal fluid (CSF), axial muscle stiffness in the special abdominal and thoracolumbar paraspinal fluid leading to hyperlordosis, painful spasms with well-defined triggers, electromyographic evidence of continuous motor unit activity, […]