Patients with<unk>  <unk>  suffer progressive stiffness in their truncal muscles (torso muscles), which become rigid and stiff because the lumbar and abdominal muscles engage in constant contractions. Initially, stiffness occurs in the thoracolumbar paraspinal and abdominal muscles. It later affects the proximal leg and abdominal wall muscles. The stiffness leads to a change in posture, and patients develop a rigid gait. Persistent lumbar hyperlordosis often occurs as it progresses. The muscle stiffness initially fluctuates, sometimes for days or weeks, but eventually begins to consistently impair mobility. As the disease progresses, patients sometimes become unable to walk or bend. Chronic pain is common and worsens over time but sometimes acute pain occurs as well. Stress, cold weather, and infections lead to an increase in symptoms, and sleep decreases them.<unk>  patients suffer superimposed spasms and extreme sensitivity to touch and sound. These spasms primarily occur in the proximal limb and axial muscles. There are co-contractions of agonist and antagonist muscles. Spasms usually last for minutes and can recur over hours. Attacks of spasms are unpredictable and are often caused by fast movements, emotional distress, or sudden sounds or touches. In rare cases, facial muscles, hands, feet, and the chest can be affected and unusual eye movements and vertigo occur. There are brisk stretch reflexes and clonus occurs in patients. Late in the disease's progression, hypnagogic myoclonus can occur. Tachycardia and hypertension are sometimes also present. Because of the spasms, patients may become increasingly fearful, require assistance, and lose the ability to work, leading to depression, anxiety, and phobias, including agoraphobia and dromophobia. Most patients are psychologically normal and respond reasonably to their situations. Paraneoplastic<unk>  tends to affect the neck and arms more than other variations. It progresses very quickly, is more painful, and is more likely to include distal pain than classic<unk> . Patients with paraneoplastic<unk>  generally lack other autoimmune issues but may have other paraneoplastic conditions. Stiff-limb syndrome is a variant of<unk> . This syndrome develops into full<unk>  about 25% of the time. Stiffness and spasms are usually limited to the legs and hyperlordoisis generally does not occur. The stiffness begins in one limb and remains most prominent there. Sphincter and brainstem issues often occur with stiff-limb syndrome. Progressive encephalomyelitis with rigidity, another variant of the condition, includes symptoms of<unk>  with brainstem issues and autonomic disturbances. It involves polio-encephalomyelitis in the spine and brainstem. There is cerebellar and brainstem involvement. In some cases, the limbic system is affected, as well. Most patients have upper motoneuron issues and autonomic disturbances. Jerking<unk>  is another subtype of the condition. It begins like classical<unk>  and progresses for several years; up to 14 in some cases. It is then distinguished by the development of myoclonus as well as seizures and ataxia in some cases.
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