What Is Tardive Dystonia?
As the name suggests, dystonia is a state of abnormal muscle tone. Tardive dystonia is a type of dyskinesia which is a neurological syndrome characterized by involuntary muscle movement due to long-term use of drugs used to treat psychiatric and gastrointestinal disorders that block the dopamine receptor in the area of the brain called the striatum, resulting in muscle spasms. It is most likely to be seen in patients with schizophrenia and other neuropsychiatric disorders. For some unknown reason, not every person on the antipsychotic drug is expected to have the symptoms of dystonia, but once a person presents with the symptoms, they might continue to display these symptoms throughout their life. Tardive dystonia is a severe form of dyskinesia that is characterized by slow twisting movements of the neck and extremities.
What Is the Etiology of the Disease?
The disorder is mainly caused by antipsychotic drugs that block dopamine receptors, followed by drugs used in the treatment of gastrointestinal conditions.
Below mentioned are a few medications that have the potential to develop dystonia or dyskinesia when used for long durations.
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Chlorpromazine.
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Fluphenazine.
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Haloperidol.
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Perphenazine.
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Prochlorperazine.
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Thioridazine.
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Trifluoperazine.
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Metoclopramide.
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Prochlorperazine.
TD develops mostly on long-term use of any of the above-mentioned medications but in some cases, it is found to occur even after a short span of treatment.
What Does Tardive Dystonia Look Like?
A person with TD presents with involuntary slow jerking movements of various long muscles of the neck, face, and extremities. Early symptoms of TD are presented as slurred speech due to involuntary movement of the tongue, continuous blinking of the eye, cramping of the legs, and involuntary movements of the neck.
A person with tardive dystonia presents with the following symptoms:
1. Orofacial Dyskinesia
This is one of the most common and characteristic features of patients with dystonia. It presents as:
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Rapid blinking of the eye.
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Protruded tongue that is involuntary.
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Smack lips, fish-like movements of lips.
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Shaky, jerky neck.
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Facial grimacing.
2. Dyskinesia of the Limbs
It is found in some patients and presents as:
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Swinging side to side.
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Tremors in the hands and fingers.
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Unwitting tapping of the feet.
The speed and intensity of the movements can vary depending on the course, doses, and duration of the drugs taken.
Due to the above symptoms, it is difficult for a person to carry out regular chores efficiently.
How Is Tardive Dystonia Diagnosed?
To be diagnosed with tardive dystonia, a person must present the following symptoms:
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A person must have dystonic movements.
- Muscle spasms that cause repetitive movements or irregular posture.
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A state of abnormal muscle tone must develop during or within 3 months of having antipsychotic medication.
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Any other neurological sign should be absent.
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The patient should report negative family history as it helps to confirm a diagnosis that dystonia is caused by antipsychotic drugs.
The diagnosis of the disease is difficult as a person might present with the symptoms months or years during or after treatment; this uncertain duration of onset makes the diagnosis tedious. Various tests can help a physician to confirm the diagnosis and differentiate TD from other dystonia, which is as follows:
1. Abnormal Involuntary Movement Scale (AIMS):
It is a physical exam that your physician can ask you to undergo as it helps in rating any abnormal involuntary muscle movements. A visit to the physician at least once a year is a must for a person on any medication with the potential risk of developing TD to prevent further complications.
2. Blood Test:
A physician can carry out blood tests to confirm the diagnosis and rule out other disorders with similar symptoms like cerebral palsy, Huntington’s disease, etc.
3) Image scanning of the brain.
What Neurological Conditions Can Tardive Dystonia Be Confused With?
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Huntington’s disease/ Huntington’s chorea.
Is There Any Cure for TD?
Tardive dystonia is difficult to diagnose as the duration of onset is not determined.
The treatment, first and foremost, aims at controlling involuntary movements and preventing the progress of the disease.
When a person reports involuntary muscle movement, the following steps are taken to determine the disorder and treat it accordingly:
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It is evaluated if a person is on any potential drug causing involuntary movements like antipsychotic drugs.
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If the person is on medications, the doses are reduced or discontinued after evaluating the need and consequences.
There is no definitive treatment available for the disorder, but available treatment options aim at minimizing or controlling the symptoms. It includes supplements like melatonin, vitamin B6, and vitamin E. These supplements help control involuntary movements but should never be taken without consulting your physician as they might interact with the ongoing prescription and cause undue reactions.
Following are the FDA-approved medications to treat tardive dystonia.
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Deutetrabenazine.
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Valbenazine.
These medications regulate the dopamine flow in the brain, which helps control involuntary muscle movement. It has been found that the potential side effects of these drugs include drowsiness. Deutetrabenazine has been reported to cause depression in patients with Huntington’s disease.
Conclusion:
Tardive dystonia is a disorder caused due to prolonged use of antipsychotic drugs that presents as involuntary muscle movement of the neck, tongue, mouth, and sometimes the extremities. The symptoms of the disease resemble other neurological disorders like Huntington’s disease/ Huntington’s chorea, cerebral palsy, and Tourette syndrome. It can be diagnosed and differentiated from other dystonias by abnormal involuntary movement scales, blood tests, and brain imaging. The treatment of the disease mainly aims at controlling the symptoms of the disorder. Vitamin supplements may also be added to the treatment regimen. When dystonia is diagnosed at the onset of treatment, a physician decides to either reduce the dose or discontinue the medications causing involuntary movements.
