neurologic disorders
Stiff Person Syndrome
Introduction
Stiff-person syndrome is a CNS disorder that causes progressive muscle stiffness and spasms. (See also Overview of Peripheral Nervous System Disorders .) Stiff-person syndrome (formerly called stiff-man syndrome) affects the central nervous system (CNS) but has neuromuscular manifestations. Most patients with stiff-person syndrome have antibodies against glutamic acid decarboxylase (GAD), the enzyme involved in the production of the inhibitory neurotransmitter GABA (gamma-aminobutyric acid). However, stiff-person syndrome may be Autoimmune Paraneoplastic Idiopathic often occurs with type 1 Diabetes Mellitus (DM) , as well as other autoimmune disorders including . Antiamphiphysin antibodies are often present; anti-GAD are usually not. Paraneoplastic stiff-person syndrome is commonly associated with breast cancer but may also occur in patients with lung, renal, thyroid, or colon cancer or Hodgkin Lymphoma . Clinical manifestations of stiff-person syndrome are similar in all types. Muscle stiffness, rigidity, and spasms progress insidiously in the trunk and abdomen and, to a lesser degree, in the legs and arms. Patients are otherwise normal, and examination detects only muscle hypertrophy and stiffness. Stiff-person syndrome typically progresses, leading to disability and stiffness throughout the body. Diagnosisof stiff person syndrome is based on recognizing the symptoms and is supported by antibody testing, response todiazepam, and results of electromyography (EMG) studies, which show the electrical activity of apparent normal contraction. 