Athetosis is a neurological condition characterized by involuntary, slow, writhing movements. It is not a disease itself, but rather a symptom of underlying brain issues. The term “athetosis” originates from a Greek word meaning “without position or place.” It is recognized as a hyperkinetic movement disorder.
Characteristics of Athetosis
Athetosis manifests as movements particularly noticeable in the distal parts of the limbs like the fingers and toes. These movements are often described as worm-like and can affect the hands, legs, and trunk. The involuntary motions are typically unpredictable, fluctuating in intensity, and may worsen when a person attempts to control their movements or maintain a specific posture.
Beyond the limbs, athetosis can involve the face, neck, and tongue, leading to challenges with everyday activities. This can result in grimacing, difficulties with speech (dysarthria), and problems swallowing (dysphagia). Unsteadiness is also common. While athetosis involves continuous, flowing movements, it differs from chorea, which presents with more jerky, rapid, and irregular motions. It also differs from dystonia, characterized by sustained muscle contractions leading to twisting postures. However, athetosis and chorea can sometimes occur together, a condition known as choreoathetosis.
Underlying Causes
Athetosis primarily stems from damage to specific areas of the brain, particularly the basal ganglia. The basal ganglia, located deep within the brain, are responsible for smoothing out muscle movements and coordinating postural changes. When these areas are damaged, nerve impulses lose proper control, resulting in uncoordinated muscle movements.
A common cause of athetosis, especially in children, is dyskinetic cerebral palsy. This type of cerebral palsy often results from brain injury that occurs around the time of birth. Another cause in newborns is kernicterus, a severe form of jaundice where high levels of bilirubin can become toxic to the brain. Lack of oxygen or blood flow to the brain, known as anoxia or stroke, can also lead to subsequent athetosis, particularly in adults. Less commonly, certain neurodegenerative conditions like Huntington’s disease or metabolic disorders such as Wilson’s disease can also cause athetosis.
Diagnosis
The diagnosis of athetosis primarily relies on a thorough neurological examination and careful observation of the characteristic involuntary movements. A medical professional will assess the type, distribution, and severity of the movements. Gathering a detailed patient history is also important, which includes information about birth complications for children or any past medical events like strokes or head injuries.
While athetosis is diagnosed clinically, brain imaging, such as an MRI, is often performed. These imaging tests do not directly diagnose athetosis but are used to identify the underlying brain damage or abnormalities responsible for the movements. Blood tests may also be conducted to rule out metabolic or genetic conditions that could be contributing factors. The diagnostic process also involves differentiating athetosis from other movement disorders that might present with similar symptoms.
Management Approaches
Managing athetosis typically involves a multidisciplinary approach focused on alleviating symptoms, improving function, and enhancing quality of life, as there is currently no cure. Therapeutic interventions are a primary part of this management. Physical therapy helps improve range of motion, muscle strength, and balance, while occupational therapy assists with daily living activities and suggests adaptive equipment. Speech therapy addresses communication difficulties and swallowing problems caused by facial and oral muscle involvement.
Medications can help reduce the severity of involuntary movements, though effectiveness varies. Examples include muscle relaxants, anticholinergics, or drugs that influence neurotransmitters like dopamine. Botulinum toxin injections may be considered for specific severely affected muscles to reduce contractions.
Assistive devices, such as braces, walkers, specialized seating, or communication aids, can significantly improve independence and functional abilities. Surgical options, such as deep brain stimulation, are generally considered only in severe cases where other treatments have not been effective. An individualized treatment plan, tailored to each person’s specific needs, is important for effective management.