dystonias

Dystonias are a group of movement disorders characterized by sustained or intermittent muscle contractions that cause abnormal postures or twisting movements. These contractions can affect a single body part (focal dystonia), adjacent regions (segmental dystonia), multiple regions across the body (generalized dystonia), or noncontiguous areas (multifocal dystonia). Symptoms may be task-specific, worsened by voluntary movement or stress, and may include pain or fatigue. Many patients experience sensory tricks that temporarily reduce symptoms.

Pathophysiology is not fully understood but is thought to involve dysfunction in the brain’s motor circuits, particularly the basal ganglia and their connections. Dystonias arise from a combination of genetic and environmental factors. Primary (idiopathic) dystonias often run in families and are linked to genetic mutations, while secondary dystonias result from brain injury, stroke, infections, or exposure to certain medications (notably dopamine-blocking or dopamine-depleting drugs). Docal presentations include focal forms such as cervical dystonia, blepharospasm, oromandibular dystonia, and writer’s or musician’s dystonia, as well as generalized forms that begin in childhood or adolescence and may progress.

Diagnosis is clinical, based on history and neurological examination, with imaging and laboratory studies used to exclude other conditions or identify treatable causes. Genetic testing may support a diagnosis in familial cases.

Treatment aims to reduce symptoms and improve function. Botulinum toxin injections are first-line for focal dystonias. Oral medications such as anticholinergics, baclofen, or tetrabenazine may help some patients. Deep brain stimulation of the globus pallidus internus is considered for refractory generalized dystonia or focal dystonia causing substantial disability. Rehabilitation and physical therapy are important, and management of underlying conditions is essential (for example, treating Wilson’s disease).

Prognosis varies by type and severity but many patients experience chronic symptoms that can be improved with appropriate therapy and multidisciplinary care.