What is Chorea?
Chorea is a medical condition and a type of movement disorder, which results in unpredictable and involuntary movements of the body without any specific pattern. This can be as mild as just a jerk to as worse as wild involuntary movements of the arms and legs. Symptoms of chorea range from minor movements, such as fidgeting to more severe and profound uncontrolled movements of the arms and legs.
Treatment for Chorea comprises of treating the underlying condition which is causing chorea.
What Causes Chorea?
A number of medical conditions can cause chorea. Some of them are temporary and some are chronic. A thorough medical history is required to determine the exact cause. Some of the causes of Chorea include:
- Immune disorders, such as SLE or systemic lupus erythematosus can cause Chorea.
- Genetic disorders, such as Huntington's disease.
- Sydenham's chorea occurs from rheumatic fever which is an infection-related medical condition.
- Certain medications, such as neuroleptics and levodopa can cause chorea.
- Pregnancy can also cause chorea, also known as chorea gravidarum.
- Hypoglycemia and other such endocrine or metabolic disorders can also cause chorea.
What are the Risk Factors for Chorea?
- Risk factors for chorea are related to the individual risk for the disease, which causes chorea.
- Patients who have a previous history of rheumatic fever are more prone to develop chorea.
- Pregnant women are more likely to develop chorea, also known as chorea gravidarum.
- Patients who have Huntington's disease, which is a hereditary disorder, are more likely to develop chorea.
- Rheumatic Fever: This is by far the most common cause of Chorea and if an individual suffers from this is more likely to suffer from Chorea than others.
- Family History: An individual with a family history of Chorea has about 60% chances of developing this disease as well.
- Genetic Conditions: Certain genetic factors are also responsible for development of Chorea. Genetic mutations which result in development of Huntington Disease predispose the individual to development of Chorea.
Types of Chorea
According to research, chorea is one of the three types of hyperkinetic disorder. Chorea is a type which causes involuntary rapid movements. Ballismus or choreoballismus is another type which causes a more severe type of jerking movements, which are potentially dangerous as they can cause injury. Athetosis, also known as choreoathetosis, is a type of Chorea which causes slow and writhing movements of the body.
What are the Signs & Symptoms of Chorea?
Symptoms of and the severity of chorea depends on the underlying condition causing it. A grip known as the "milkmaid" grip is one of the common symptom of chorea. Patient looks as if he/she is holding an eating utensil; however, the thumb is pointing upwards. Involuntary sticking out of the tongue is another symptom. The movements of the chorea can be slow or fast. A patient may appear to have writhing movements like in pain and appears to have no control over his/her body.
Symptoms of chorea depend on the underlying cause such as:
Symptoms of Chorea Caused Due To Neuroacanthocytosis
This is a genetic disorder which affects the functioning of the brain. Chorea for this condition often starts as tongue or lip biting because of the involuntary sticking out of the tongue.
Symptoms of Chorea Caused due to Huntington's Disease
When patients with Huntington's disease experience the initial chorea symptoms, they mistakenly think of it as nervousness or clumsiness. Chorea is a common symptom in patients with adult-onset Huntington's disease and is less common in patients who have Huntington's as children or have juvenile Huntington's disease. Gradually there is worsening of the symptoms affecting arms and legs.
Symptoms of Chorea Caused due to Sydenham's Chorea
Rheumatic fever causes Sydenham's chorea. Patients suffering from this type of chorea commonly have the milkmaid grip. Developing "harlequin tongue" is another common symptom where the patient constantly tries to stick the tongue out, however, the tongue pops in and out instead.
Investigations to Diagnose Chorea
A thorough medical history and physical exam is conducted so as to diagnose Chorea. The doctor will ask certain questions such as:
- When did you start experiencing the symptoms?
- What worsens or alleviates the symptoms? (As the chorea symptoms tend to worsen when the patient is under stress.)
- What medications are you taking currently?
- Is there a family history of Huntington's disease or hyperthyroidism?
There are some laboratory tests which can indicate chorea, such as:
- A low level of copper indicates Wilson disease, which is a genetic disorder that causes chorea.
- If the blood test shows spiky red blood cells or erythrocytes, then it indicates neuroacanthocytosis.
- Blood test to check for thyroid or parathyroid hormones can indicate endocrine or metabolic-related chorea.
- Imaging studies can be done to check the brain activity and these include MRI or CT scan of the brain. This can help in diagnosing Huntington's disease which causes chorea.
How is Chorea Treated?
Treatment for chorea depends upon the type of chorea which the patient has. Antibiotics are given for treating Sydenham's chorea. There is no cure for Chorea from Parkinson's disease. Treating the underlying condition helps in treating and alleviating the chorea symptoms.
Medications to Treat Chorea
Majority of the medications for treating chorea affect dopamine, which is a brain chemical or a neurotransmitter which controls thinking, movement, pleasure etc. Dopamine levels are associated with many movement disorders, such as Parkinson's disease and restless legs syndrome. There are some medicines, which block the receptors of the dopamine so that the body cannot use this neurotransmitter. These medicines come under the "antipsychotic" category and help in reducing chorea. These medications include: Fluphenazine, haloperidol, olanzapine, quetiapine, risperidone. Other medicines which decrease the amount of dopamine in the brain include reserpine and tetrabenazine. Benzodiazepines, such as clonazepam, also help in relieving the symptoms of chorea. Anticonvulsants are that class of medication, which reduces chorea's spontaneous movements.
Home Care for Chorea
Chorea tends to increase the risk of falls in a patient. Home care measures, such as installing hand rails, non-slippery surfaces on the stairs and in bathrooms help in preventing falls and injury.
Surgery for Chorea
Surgical procedures, which can help in treating chorea, include deep brain stimulation where electrodes are implanted in the brain to help regulate the nerve impulses. This procedure is recommended if the chorea is not responding to medications. It does not cure chorea, but helps in alleviating the symptoms.
Prognosis for Chorea
The prognosis of chorea depends on the underlying condition causing it. Sydenham's chorea can be cured by antibiotics, whereas, there is no cure for Huntington's disease. Women suffering from chorea gravidarum usually stop having symptoms around after six weeks after giving birth. Chorea resulting from endocrine or metabolic disorders subsides after the imbalance is treated.