<unk>  <unk> , also known as<unk> -man syndrome (SMS), is a rare neurologic disorder of unclear cause characterized by progressive rigidity and<unk> ness. The<unk> ness primarily affects the truncal muscles and is superimposed by spasms, resulting in postural deformities. Chronic pain, impaired mobility, and lumbar hyperlordosis are common symptoms.<unk>  occurs in about one in a million people and is most commonly found in middle-aged people. A small minority of patients have the paraneoplastic variety of the condition. Variants of the condition, such as<unk> -limb syndrome which primarily affects a specific limb, are often seen.<unk>  was first described in 1956. Diagnostic criteria were proposed in the 1960s and refined two decades later. In the 1990s and 2000s the roles of antibodies in the condition became more clear.<unk>  patients generally have GAD antibodies, which seldom occur in the general population. In addition to blood tests for GAD, electromyography tests can help confirm the condition's presence. Benzodiazepine-class drugs are the most common treatment; they are used for symptom relief from<unk> ness. Other common treatments include baclofen, intravenous immunoglobin and rituximab. There is a limited but encouraging therapeutic experience of hematopoietic stem cell transplantation for<unk> .
Stiff-person syndrome
Parkinson-plus syndrome
Dejerine–Roussy syndrome
Mauriac syndrome
Stiff skin syndrome
Dopamine-responsive dystonia
Huntington's disease-like syndrome
Benign fasciculation syndrome