What is Tardive Dyskinesia?
Tardive dyskinesia (TD) is a group of abnormal movement disorders caused by certain medications blocking dopamine receptors, which help transmit signals in the brain. These disorders cause unusual movements and may include restlessness, stiff or jerky movements, repetitive mouth or facial movements, uncontrolled movements, and other irregular, involuntary movements. Often, these disorders occur after long-term use of antipsychotic drugs, though other medications can also cause tardive dyskinesia.
According to the key mental health reference book, “Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM V)”, tardive dyskinesia is classified as a disorder caused by medication that continues even after you stop taking the drug. To be diagnosed with tardive dyskinesia, the symptoms must last for at least one month after discontinuing the medication.
Tardive dyskinesia is mostly seen in individuals with schizophrenia and bipolar disorder who are treated with antipsychotic medications. However, it can occur in any individual taking specific medications. In some cases, the drugs causing tardive dyskinesia can also induce symptoms similar to Parkinson’s disease. While the exact cause of tardive dyskinesia is still unknown, it is believed that abnormal dopamine transporters could play a role.
What Causes Tardive Dyskinesia?
Tardive dyskinesia is a condition that can occur after long-term use of certain types of medication. This includes medication for mental health conditions known as first and second-generation neuroleptics, certain types of antidepressants, a medication called lithium, and some drugs used to prevent nausea or vomiting.
Particularly, the first-generation neuroleptics, which strongly interact with a part of the brain’s reward system known as dopamine D2 receptors, are more likely to cause tardive dyskinesia. On the other hand, some newer forms of these neuroleptics, called atypical antipsychotics, have a lower risk. This is because they interact less with these dopamine D2 receptors in a region of the brain known as the dorsal striatum, and they also block other receptors called serotonin 5-HT2A/2C receptors. This makes them less likely not only to cause tardive dyskinesia, but also to cause other side effects related to movement.
Moving away from neuroleptics, a drug called metoclopramide can also cause tardive dyskinesia. This is particularly a risk in older people. In addition, certain drugs for allergies and itching (antihistamines), a certain antidepressant called amoxapine, and another antidepressant called fluoxetine can also potentially cause the condition.
Risk Factors and Frequency for Tardive Dyskinesia
Tardive dyskinesia, a movement disorder, is pretty common in patients treated with an older type of psychiatric drugs known as first-generation neuroleptics. About 20% of these patients develop the condition. Other medications can cause tardive dyskinesia too, but we don’t have much data on them. Estimates suggest that between 1% and 10% of patients on these other drugs may get tardive dyskinesia.
There are several factors that can increase a person’s chances of developing this disorder. These include:
- Gender and age: Women, particularly middle-aged to elderly women, are at a higher risk. In fact, up to 30% of post-menopausal women may develop the condition after a year of using certain antipsychotic medications. This suggests that estrogen, which decreases after menopause, may have a protective effect.
- Ethnicity: African Americans seem to develop tardive dyskinesia more often than White individuals when given long-term treatment with dopamine-blocking drugs.
- Duration of exposure and type of drug used: The longer a patient has been on these neuroleptic drugs, the more likely they are to develop tardive dyskinesia. The risk is also higher for those who’ve had extrapyramidal symptoms (movement disorders) and those on first-generation antipsychotics, as opposed to newer versions of these drugs.
- Use of anticholinergic medications: Long-term use of these drugs can also increase the chances of developing tardive dyskinesia.
It’s worth noting that this condition can also affect the elderly more, mostly due to changes in the body and brain that come with aging.
Signs and Symptoms of Tardive Dyskinesia
Before starting treatment with certain medications that target dopamine D2 receptors, doctors need to check for any signs of movement disorders in their patients. One of these disorders is tardive dyskinesia, which is marked by repetitive, involuntary movements. The movements can involve the tongue, neck, face, trunk, and limbs. You might observe actions like lip smacking, sticking out the tongue, around-the-mouth movements, chewing movements, or puffed cheeks. These actions can be challenging to identify in patients with long-term psychosis, but tardive dyskinesia typically appears in patients who have been exposed to drugs that block dopamine D2 receptors for an extended period of time.
The start of tardive dyskinesia can sneak up slowly and start off with very subtle abnormal movements. The signs of this disorder can show up anywhere from 1 to 6 months after starting a medication that targets dopamine receptors. Diagnosing these types of movement disorders, whether they’re short- or long-term, can be tricky if there’s no thorough background. Having a complete background of any movement disorders and history of medications can make it easier to identify tardive dyskinesia.
Negative side effects related to medications that impact dopamine can include:
- Tardive akathisia
- Tardive orofacial dyskinesia
- Tardive dystonia
- Tardive blepharospasm
- Tardive tics
Testing for Tardive Dyskinesia
Tardive dyskinesia is a condition that can be identified and evaluated using various rating scales. The most popular scale used by health professionals is the Abnormal Involuntary Movement Scale (AIMS). It’s best to use the AIMS before starting medications used to manage psychosis and follow up with another screening within a span of three months. Tardive dyskinesia is often noticeable when the patient is resting and may reduce during voluntary movements. For instance, abnormal tongue movements may decrease when the patient is asked to stick out their tongue.
If tardive dyskinesia is detected along with dementia, it might be necessary to evaluate for diseases such as Huntington’s disease, Wilson’s disease, or brain tumors. A diagnosis of tardive dyskinesia, triggered by antipsychotic medications, is only made when the symptoms have lasted for a minimum of one month and the patient has been taking antipsychotic drugs for at least three months. It’s important to distinguish tardive dyskinesia from withdrawal dyskinesias, as the latter usually goes away after the psychotic medication is stopped.
When checking for tardive dyskinesia, certain laboratory tests and imaging may be required. Generally, brain scans like CT and MRI show normal results in patients with tardive dyskinesia. However, these scans can help rule out other conditions like Huntington’s disease, which may show deterioration of a part of the brain called the caudate nucleus, and Fahr syndrome, where there is a build up of calcium in a part of the brain known as the basal ganglia.
Treatment Options for Tardive Dyskinesia
Doctors should try to avoid prescribing drugs known as dopamine receptor antagonists, when possible. This is because these drugs can sometimes cause a condition called tardive dyskinesia, which is a side effect involving involuntary movements. It’s also recommended that long-term use of a type of drugs called first-generation antipsychotics be avoided, as they can also cause tardive dyskinesia.
Treatment options for tardive dyskinesia are limited to date. The American Academy of Neurology only suggests a few, including a drug called clonazepam and an herbal supplement known as ginkgo biloba.
Valbenazine, a drug that alters the activity of certain chemicals in the brain, was approved by the FDA on April 11, 2017, for treating tardive dyskinesia. Results from a trial known as KINECT 3 showed that Valbenazine improved the condition compared to a placebo, a substance with no therapeutic effect.
However, the best approach to managing tardive dyskinesia is to prevent it in the first place, usually by careful selection and use of medications.
What else can Tardive Dyskinesia be?
There are several conditions that could be mistaken for each other due to similar symptoms. These include:
- Chorea – a disorder causing irregular, uncontrolled movements
- Complex seizure – a type of epilepsy that can cause loss of consciousness and uncontrolled movements
- Essential tremor – a nervous system disorder that causes rhythmic shaking
- Tourette syndrome – a neurological disorder characterized by repetitive, stereotyped, involuntary movements and vocalizations called tics
- Tic disorder – a condition where a person has tics – sudden twitches, movements, or sounds that they do in an uncontrollable way
- Wilson disease – a genetic disorder that causes copper to accumulate in the body, leading to neurological symptoms
- Sydenham chorea – a neurological disorder of childhood resulting from infection via Group A beta-hemolytic streptococcus, the bacterium that causes rheumatic fever
What to expect with Tardive Dyskinesia
Tardive dyskinesia is a condition that unfortunately tends to be chronic and ongoing. As of now, there isn’t a solution to completely eliminate tardive dyskinesia. However, there are supportive measures available that can help reduce the severity of the symptoms.
Possible Complications When Diagnosed with Tardive Dyskinesia
Tardive dyskinesia is a condition that worsens over time, leading to immense discomfort and possibly causing embarrassment. Though it’s typically not a threat to life, intense tardive dyskinesia involving the voice box and diaphragm can potentially be deadly.
Common Effects of Tardive Dyskinesia:
- Progressive discomfort
- Potential embarrassment
- Usually not life-threatening
- Severe version affecting voice box and diaphragm can be fatal
Preventing Tardive Dyskinesia
The best way to prevent a condition known as tardive dyskinesia, which causes involuntary, repetitive body movements, is to avoid it in the first place. This is typically achieved by using the smallest dosage that still effectively treats the condition of an antipsychotic medication, and only for a short time if possible. If symptoms of tardive dyskinesia start to appear anyway, the recommended course of action is to lower the dose of the medication or even stop using it altogether. Instead, a medication called clozapine may be used. This is because clozapine has been found to cause tardive dyskinesia less frequently than other antipsychotic drugs, making it a good option for patients who still need to take this type of medication.
