Athetosis is a movement dysfunction. It’s characterized by involuntary writhing movements. These movements may be continuous, slow, and rolling. They may also make maintaining a symmetrical and stable posture difficult.
With athetosis, the same regions of the body are repeatedly affected. These typically include the hands, arms, and feet. The neck, face, tongue, and trunk can be involved, too.
While athetosis may be continuous, it can get worse with attempts to control movement. For example, if a person with the condition tries to type on a computer keyboard, they may have extreme difficulty controlling where their fingers land and how long they remain.
Learning about the symptoms of athetosis and what causes it can help you better understand if the condition is affecting you or someone you love.
Signs and symptoms of athetosis include:
- slow, involuntary, writhing muscle movements
- random and unpredictable changes in muscle movement
- worsening symptoms with attempts at controlled movement
- worsening symptoms with attempts at improved posture
- inability to stand
- difficulty talking
People with athetosis may also experience muscle “overflow.” This occurs when you attempt to control one muscle or muscle group and experience uncontrolled movement in another muscle group. For example, when you attempt to talk, you may see increased muscle activity in the arm.
Athetosis and chorea are very similar. In fact, they can occur together. When they do, they’re jointly called choreoathetosis. Athetosis, with its flowing and writhing movements, is sometimes called slow chorea.
Symptoms of chorea include:
- brief and irregular movements
- dancelike jerking and rhythmic movements
- sudden muscle contractions
- involuntary movements that begin and end abruptly and unpredictably
Chorea primarily affects the face, mouth, trunk, and limbs.
Dystonia is also a movement disorder. It involves involuntary and sustained muscle contractions. This can be twisting, repetitive movements. Like athetosis, dystonia can make maintaining a normal posture difficult.
Symptoms of dystonia include:
- one or more repeated postures
- persistent or intermittent muscle contractions
- abnormal, repetitive movements
- asymmetrical posture
- potential involvement of the trunk, legs, neck, or arms
- involvement of one muscle group or several
Symptoms of dystonia may worsen when you attempt to control muscle movement. “Overflow” is also common with dystonia. Overflow is when you try to use one group of muscles, but another group begins to move involuntarily.
Athetosis is often the result of complications from birth. It can also be a symptom of certain neurological diseases. Rarely, it’s caused by stroke or trauma.
Causes of athetosis include:
Basal ganglia diseases
Damage or diseases in this part of the brain may lead to symptoms of athetosis. The basal ganglia are responsible for smoothing out muscle movements and coordinating changes in posture. When they’re not able to control nerve impulses properly, uncoordinated muscle movements may occur.
If a baby is cut off from air supply during birth, their risk for developing athetosis is higher. Asphyxia, or a lack of sufficient oxygen levels, can damage the brain. It also cuts off the supply of necessary nutrients and increases dopamine levels in the brain. These effects may damage the basal ganglia.
In a newborn, high levels of bilirubin after birth can damage the basal ganglia. Treatment may lower levels of the compound, but the blood-brain barrier that protects adults from toxins in the body isn’t properly formed at this young age. Thus, the bilirubin may be able to penetrate the brain and cause lasting damage.
Cerebral palsy (CP)
CP is caused by abnormal development or damage to the brain. This damage affects a child’s ability to control muscle movement.
CP that’s primarily associated with damage to the basal ganglia is known as athetoid cerebral palsy. This type of CP can be caused by asphyxia and high bilirubin levels.
Drugs that increase levels of dopamine in the brain may damage the basal ganglia and cause symptoms of athetosis.
Athetosis may also occur after a stroke or trauma in adults. Damage to the brain may interfere with neuron movement. This can lead to symptoms of athetosis and other movement disorders.
Athetosis is a symptom of a disorder; it’s rarely a disorder by itself. That’s why your doctor will work to diagnose the underlying cause of the movement issues. Once the cause is identified, the doctor can treat it. That should help eliminate or limit symptoms of athetosis.
To diagnose the underlying cause, your doctor will perform:
- a full medical history
- a physical exam
- blood tests
- brain imaging tests
- gross motor function tests
Each of these tools is designed to help your doctor evaluate your symptoms and rule out possible causes. There are no definitive tests for many of the possible causes of athetosis, so it may take some time before a diagnosis is reached.
Treatment for the movement disorder focuses on the underlying cause. If the condition that leads to the irregular muscle movements is treated, the accompanying symptoms should be reduced or eliminated.
Sometimes, specific treatments may be used to reduce the severity of the movements separate from other treatments. These include:
- anti-dopamine medicines: drugs that suppress the hormone’s effect on the brain
- Botox injections: treatment that may temporarily limit involuntary muscle actions
- occupational therapy: muscle training to regain some control
In most cases, athetosis is a long-term symptom of a chronic condition. As long as the underlying cause exists, the muscle movements will remain.
If the disorder is detected early, doctors can begin to look for an underlying condition. Likewise, you may also begin treatment and occupational therapy. This early intervention is the best way to help manage changes in ability and functions.
People with severe forms of the movement disorder will often require a caregiver. The uncontrolled, writhing muscle movements can make day-to-day activities difficult. This includes walking, standing, sitting, and feeding. However, it’s important to remember that there are services available that can increase independence and assist with home modifications, employment, and transportation.