Athetosis

Atetosis is a movement disorder characterized by slow, continuous, involuntary, writhing movements that are often irregular and more pronounced in the hands, feet, face, and tongue. These movements may flow into abnormal postures and can be triggered or intensified by voluntary activity or emotional states. Athetosis is classically seen as part of dyskinetic cerebral palsy, which results from early brain injury affecting the basal ganglia and related circuits.

Cause and pathophysiology: Athetosis most commonly arises from damage to the basal ganglia, particularly the caudate nucleus and putamen, or from perinatal brain injury such as hypoxic-ischemic events. It can be associated with kernicterus in infancy, though advances in neonatal care have reduced its incidence. The underlying pathophysiology involves disruption of motor circuits that regulate movement, leading to an excess of involuntary, slow, writhing activity and abnormal posturing.

Clinical features: In addition to limb movements, athetosis can affect the orofacial region, causing problems with feeding, speech, and swallowing. Movements are continuous and intertwine with dystonia and sometimes chorea, making clinical presentation described as choreoathetosis. The condition is usually non-progressive in terms of the underlying brain injury (as in cerebral palsy), but the motor manifestations persist and can change in severity with age and environment.

Diagnosis: Diagnosis is clinical, based on characteristic movement patterns and history of early brain injury. Neuroimaging, especially MRI, helps identify basal ganglia injury or other perinatal brain insults. Other tests are typically aimed at ruling out secondary causes.

Treatment and prognosis: There is no cure. Management focuses on improving function and reducing disability through physical and occupational therapy, assistive devices, and supportive care. Pharmacologic options include anticholinergics, benzodiazepines, baclofen, and in some cases tetrabenazine or botulinum toxin for focal symptoms. Deep brain stimulation of the GPi may be considered for severe, disabling cases. The prognosis depends on the extent of early brain injury and coexisting disabilities; movements may remain persistent but functional goals can be achieved with multidisciplinary care.