What Is Athetosis?

Athetosis is a type of involuntary movement that can occur with medical conditions. It is characterized as slow writhing movements of the extremities. While it can be used to describe movement patterns, athetosis also refers to athetoid cerebral palsy, also known as dyskinetic cerebral palsy.

If you or your child has athetosis, you may need to undergo diagnostic tests so your healthcare providers can determine the cause and prescribe therapy for you. The condition is not curable, but some interventions can reduce it and make it more tolerable. 

Symptoms

Athetosis can begin at any age, and it generally does not improve on its own. It can increase in severity and may become more frequent over time. Athetosis can affect one or more limbs and can occur intermittently, without a consistent pattern, or almost constantly. 

The movements are involuntary, are not rhythmic, and can put the body into uncomfortable, twisted positions. They can appear as slow, fluid, rotating motions, usually involving the distal extremities, including the arms below the elbows, the hands, fingers, and feet. Athetosis can also involve the neck.

Athetosis is not the same as muscle weakness, tremors, or spasms—although it can be associated with diminished motor control, as well as other involuntary movements.

Often, the limbs affected by athetotic movements can be rigid when at rest. Chorea—an involuntary, abrupt, jerking movement of the extremities—often accompanies athetosis.

Causes

Athetosis is a symptom of an underlying disorder, and several conditions can cause athetosis, including:

• Cerebral palsy: Athetoid cerebral palsy and mixed cerebral palsy are the most common causes of athetosis. These lifelong congenital conditions are characterized by diminished motor control, often with other effects, such as diminished cognitive abilities.
• Neurological disease, brain damage, or stroke: Sometimes a brain injury, tumor, or stroke can lead to athetosis if certain parts of the brain that mediate voluntary movement are affected.
• Medications: Some of the medications used in the treatment of Parkinson’s disease or psychiatric disorders can cause athetosis as a side effect.
• Huntington’s disease: This hereditary condition involves symptoms of dementia and involuntary movements, including athetosis, beginning during adulthood.
• Metabolic disorders: A few metabolic conditions have been associated with athetosis, including Wilson’s disease, which causes an accumulation of copper in the brain and other parts of the body.

Pathophysiology 

Athetosis occurs due to dysfunction in the basal ganglia, an area of the brain involved with voluntary motor control. The basal ganglia includes the caudate, globus pallidus, putamen, and parts of the midbrain.

Most commonly, athetosis results from basal ganglia damage due to developmental brain malformation or oxygen deprivation during fetal development (which results in athetotic cerebral palsy). This area also can be impaired due to problems that develop during adulthood.

A number of other symptoms, including chorea and hemiballismus (sudden involuntary jerking of one side of the body), can also develop when these structures are impaired, which may lead to the combination of symptoms that often occur with athetosis.

Diagnosis

Your healthcare provider would identify whether you have athetosis based on an observation of your movements. Sometimes athetosis develops after a condition, such as cerebral palsy, has already been diagnosed. It can, however, be one of the early symptoms of a neurological disorder.

The diagnosis is based on the age when the symptoms started, as well as other factors, such as medical history and other symptoms. 

As part of your evaluation for athetosis, your healthcare provider would perform a comprehensive neurological examination, which can identify signs of your underlying condition. 

Additionally, you might have diagnostic tests.

• For athetosis beginning before age 2, cerebral palsy or metabolic disorders would be considered as a potential cause. Magnetic resonance imaging (MRI) may be ordered to identify malformations or other changes in the brain.
• Adults who may have sustained a stroke or another form of brain damage may have a brain imaging study to identify a potential causative lesion.
• Adults who have a risk of Huntington’s disease might have a genetic test to determine if that could be the cause. 

Treatment

While athetosis isn’t curable, there are treatments that can help reduce it. Underlying conditions are usually treated to control other associated symptoms as well.

Treatments used for controlling athetosis generally involve physical therapy and occupational therapy, which can help improve muscle control and the ability to carry out activities of daily living.

Music therapy may also be beneficial for reducing movement problems and improving balance in cerebral palsy, including athetosis.

Medical interventions include:

• Medications, including muscle relaxants and anti-epileptic drugs (AEDs), are used to reduce muscle tone.
• Injections of botulinum toxin can help weaken the muscle, reducing the movements that the muscle can make.
• Deep brain stimulation (DBS) is a procedure that has been examined as a potential treatment for athetosis. This treatment involves surgical implantation of a stimulator near the globus pallidus. It has shown some beneficial effects, but it is unclear whether the procedure offers lasting benefits or improved quality of life.

Coping

Living with athetosis can be challenging. It is important that you speak with your healthcare provider and physical therapist about this symptom.

You may be able to use devices designed for people who have athetosis. For example, an electric wheelchair designed with a special grip to accommodate people who have athetosis can help improve your ability to get around.

A Word From Verywell 

Athetosis can be one of the more uncomfortable symptoms of cerebral palsy and some other conditions. Managing athetosis involves a number of strategies.

This movement problem generally occurs along with other symptoms, and the overall impact of athetosis may be reduced when other effects are managed.