Dystonia Causes and Classification

Primary Causes of Dystonia

Dystonia can be caused by genetic mutations, with primary genetic forms being the most common cause of isolated dystonia, according to the American Academy of Neurology 1
Mutations in the PRRT2 gene are a major cause of paroxysmal kinesigenic dyskinesia (PKD), a form of dystonia, as reported by the National Institute of Neurological Disorders and Stroke 1
Genetic dystonias can be inherited in autosomal dominant patterns with incomplete penetrance (60-90%), as stated by the American College of Medical Genetics 1

Pure/isolated dystonia presents only with dystonic movements without other neurological symptoms, according to the International Parkinson and Movement Disorder Society 1
Complicated/combined dystonia presents with dystonia plus additional neurological symptoms such as benign familial infantile epilepsy, as reported by the American Academy of Child and Adolescent Psychiatry 2
Complicated/combined dystonia can also present with febrile convulsion, migraine or hemiplegic migraine, episodic ataxia, developmental delay, intellectual deficit, language dysfunction, and autism, as stated by the American Academy of Neurology 1, 2, 3, 4

Antipsychotic medications, particularly first-generation/typical antipsychotics, can cause dystonia, as reported by the American Academy of Pediatrics 5, 6
Acute dystonia occurs in the first few doses or after dose increases of antipsychotic medications, according to the National Institute of Mental Health 6
Risk factors for medication-induced dystonia include young age, male gender, and use of high-potency agents, as stated by the American Academy of Child and Adolescent Psychiatry 2

Wilson's disease can cause dystonia, characterized by copper accumulation, as reported by the European Association for the Study of the Liver 7
Parkinson's disease and parkinsonism can also cause dystonia, according to the International Parkinson and Movement Disorder Society 4, 8
Spasmodic dysphonia is a form of laryngeal dystonia, as stated by the American Academy of Otolaryngology-Head and Neck Surgery 4, 8

Cerebrovascular disease/stroke can cause dystonia, as reported by the American Heart Association 9
Metabolic disorders, such as hyperthyroidism, calcium-phosphate metabolism disorders, and glucose metabolism disorders, can also cause dystonia, according to the Endocrine Society 1
Brain trauma and gastroesophageal reflux (Sandifer syndrome) can cause dystonia in young children, as stated by the American Academy of Pediatrics 3, 9

Musculoskeletal tension with excessive recruitment in affected muscles (as in muscle tension dysphonia) is a key mechanism in dystonia, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 4, 8

Dystonia can manifest as dystonic movements, chorea, ballism, or mixed forms, according to the International Parkinson and Movement Disorder Society 1
Distribution of dystonia can be focal, segmental, multifocal, or generalized, as stated by the American Academy of Neurology 2