Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content + Print Section ++ For further information, see CMDT Part 24-13: Movement Disorders + Key Features Print Section ++ ++ Essentials of Diagnosis ++ Dystonic movements and postures No other neurologic signs Normal birth and developmental history Investigations (including CT scan or MRI) reveal no cause of dystonia ++ General Considerations ++ May occur sporadically or on a hereditary basis, with autosomal dominant, autosomal recessive, and X-linked recessive modes of transmission One responsible gene is located at 9q34 (and has been named DYT1) Involves a unique mutation consisting of a GAG deletion in the major dominantly inherited disorder and maps to the long arm of the X chromosome in the X-linked recessive form The responsible gene in the autosomal recessive disorder is unknown Symptoms may begin in childhood or later and persist throughout life + Clinical Findings Print Section ++ ++ Symptoms and Signs ++ Onset of abnormal movements and postures in a patient with A normal birth and developmental history No relevant past medical illness No other neurologic signs Dystonic movements of the head and neck Torticollis Blepharospasm Facial grimacing Forced opening or closing of the mouth The limbs may also adopt abnormal but characteristic postures The age at onset influences both the clinical findings and the prognosis Childhood onset A family history of the disorder is usual Initial symptoms commonly in the legs Progression is likely until there is severe disability from generalized dystonia Adult onset A positive family history is unlikely Initial symptoms are often in the arms or axial structures Severe disability does not usually occur, although generalized dystonia may ultimately develop in some patients ++ Differential Diagnosis ++ Perinatal anoxia Birth trauma Neonatal kernicterus Wilson disease Huntington disease Parkinsonism Sequela of encephalitis lethargica Neuroleptic drug therapy Dopa-responsive dystonia + Diagnosis Print Section ++ ++ Imaging Studies ++ Investigations (including MRI or CT imaging) reveal no cause for the abnormal movements + Treatment Print Section ++ ++ Medications ++ Idiopathic torsion dystonia usually responds poorly to drugs Levodopa, diazepam, baclofen, carbamazepine, amantadine, or anticholinergic medication such as trihexyphenidyl or benztropine (in high dosage) occasionally helpful If not, a trial of treatment with tetrabenazine, phenothiazines, or haloperidol may be worthwhile In each case, the dose has to be individualized, depending on response and tolerance However, the doses of tetrabenazine, phenothiazines, or haloperidol required for benefit usually lead to mild parkinsonism ++ Therapeutic Procedures ++ Pallidal deep brain stimulation Helpful for medically refractory dystonia Has a lower morbidity than stereotactic thalamotomy, which is sometimes helpful in patients with predominantly unilateral limb dystonia Potential adverse events include cerebral infection or hemorrhage, broken leads, affective changes, and dysarthria + Outcome Print Section ++ ++ Prognosis ++ A distinct variety of dominantly inherited dystonia, caused by a mutation in gene for GTP cyclohydrolase I on chromosome 14q, is remarkably responsive to levodopa; therefore a levodopa trial is warranted in all patients About one-third of patients eventually become so severely disabled that they are confined to chair or bed, while another one-third are affected only mildly ++ When to Refer ++ All patients should be referred ++ When to Admit ++ Patients requiring surgical treatment should be admitted + Reference Print Section ++ + +Fox MD et al. Brain stimulation for torsion dystonia. JAMA Neurol. 2015 Jun;72(6):713–9. [PubMed: 25894231]