Trung dystonias thuốc gây ra tardive dystonias chống loạn thần thuốc ngăn chặn thụ thể dopamine điển hình cũ và mới hơn các loại thuốc không điển hình Anxiolytic: buspirone thuốc chống trầm cảm đại lý: | CLINICAL CASES 33 Table 3-1 DIFFERENTIAL DIAGNOSIS OF DYSTONIA Secondary dystonias Drug-induced tardive dystonias Antipsychotic drugs dopamine receptor-blocking older typical and newer atypical drugs Anxiolytic drug buspirone Antidepressant agents selective serotonin-reuptake inhibitors Dopaminergic drugs levodopa and dopamine agonists Antiemetic drugs metoclopramide Antiseizure drugs phenytoin carbamazepine gabapentin Cerebral palsy Wilson disease Mitochondrial encephalopathies Neuroacanthocytosis Pantothenate kinase-associated neurodegeneration Hallervorden-Spatz disease Fahr disease APPROACH TO DYSTONIA Definitions Dystonia Sustained muscle contractions cause twisting and repetitive movements or abnormal postures. Myoclonus Sudden involuntary jerking of a muscle or group of muscles. Opisthotonos Great rigid spasm of the body with the back fully arched and the heels and head bent back. Clinical Approach Dystonia is classified according to etiology as idiopathic or symptomatic. Primary dystonia is defined as a condition with no etiology that can be identified and dystonia is the sole or major symptom. Primary dystonias are further subdivided by criteria such as age of onset distribution of affected body parts presence of diurnal variation of symptoms responsiveness to drugs and genetic markers. Secondary dystonia refers to dystonia in the context of a neurologic disease in which dystonia is only one of several symptoms or in which dystonia is the result of an environmental insult. There are at least 15 genetic causes of dystonia. Generalized dystonia tends to have its onset in childhood. A three base-pair guanine-adenine-guanine GAG deletion in exon 5 of DYT1 TOR1A is the most frequent cause of early onset generalized dystonia starting in a limb and is known as DYT-1 dystonia. However there is a large phenotypic variability even within families with an identical mutation. Primary generalized torsion dystonia is a progressive disabling disorder that usually begins
