Tardive dyskinesia shares features with other movement disorders, such as Tourette syndrome and drug-induced Parkinsonism. But a diagnostic evaluation can reveal which condition is causing the symptoms.
Tardive dyskinesia (TD) is an involuntary movement disorder that develops as a side-effect of repeated or long-term medication use. It’s associated with medications that block dopamine receptors, like antipsychotics and some gastrointestinal medications.
Over time, prolonged use of these medications can cause chemical imbalances in areas of the brain responsible for motor function.
Because TD and other movement disorders can share a variety of symptoms, it can be challenging to tell them all apart. But differences in presentation, treatment, and underlying causes set these conditions apart as separate diagnoses.
A diagnostic evaluation includes a comprehensive medical evaluation, taking a medical history, physical examination and diagnostic testing. This can reveal which condition is causing the symptoms.
Understanding the difference between TD and similar conditions can help you gain insight into the condition and why you’ve received this diagnosis.
Tourette syndrome is classified as a tic disorder, a condition characterized by the presence of uncontrollable, rapid, and repetitive movements and sounds known as “tics.”
It features simple tics (brief, repetitive sounds or movements in small muscle groups) and complex tics (coordinated sounds and movements) that chain together through different parts of the body.
Symptoms
Both Tourette syndrome and TD can involve tics. In Tourette syndrome, tics are a primary diagnostic feature. In TD, tics are one possible way involuntary movements present.
Tics in TD are also likely to be limited to the face, head, and neck, though the limbs may be affected as well.
Causes
Tourette syndrome is a condition that emerges in childhood, affecting boys
TD is by definition, a medication side effect, and most often associated with antipsychotics and antidepressants, but can also be caused by other medication types, such as antihistamines, anti seizure medications, and others.
TD
Treatment
There’s no cure for Tourette syndrome or TD, but treatment may help improve symptoms in each condition.
Tourette syndrome is treated with a variety of medications, including medications that block dopamine, which are the same types of medications most that most commonly cause TD as a side effect.
Because of this, it can be very confusing for people who are being treated for Tourette syndrome to understand whether they are experiencing a medication side effect of TD or whether their Tourette syndrome is not being adequately treated.
Close monitoring of the symptoms by your medical team is crucial to determine the difference.
The primary treatment for TD is the discontinuation of medications that caused the condition. Medications, such as deutetrabenazine (Austedo), can help with symptoms of TD.
Supportive therapies, such as deep brain stimulation (DBS), physical therapy, and Ginkgo biloba supplementation, may also be considered.
Other tic disorders include transient tic disorder and chronic motor or vocal tic disorder.
In transient tic disorder, aka provisional tic disorder, tics typically develop in childhood and resolve within 12 months with no treatment.
Chronic motor or vocal tic disorder, like Tourette’s syndrome, has childhood onset and is not a medication side effect. In contrast, TD, usually starts during adulthood and it is always a medication side effect.
Tardive syndromes (TDS) are movement disorders caused by the use of dopamine receptor-blocking medications. The word “tardive” in their names implies a universal delayed onset of symptoms.
TDS includes:
- Tardive stereotypy: Purposeful, rhythmic movements of the head, neck, torso, pelvis, and limbs.
- Tardive akathisia: Restlessness or the compulsion to move that typically affects the legs or trunk of the body.
- Tardive dystonia: Constant or recurring muscle contractions in the face, neck, trunk, and arms. It often causes unusual, twisted posture.
- Tardive tics: Repetitive, brief motor movements or vocalizations often accompanied by urges to perform that specific movement or sound.
- Tardive myoclonus: Quick, jerking movements that can affect any muscle. Especially noticeable in the arms, legs, and fingers.
- Tardive tremor: Characterized by shaking movements that typically affect the hands and arms but can be seen in any area of the body.
- Tardive gait: Unusual walking movements.
- Tardive dyskinesia: Random, repetitive muscle movements primarily of the face but can also be seen in the arms, legs, fingers, toes, and pelvis.
Tardive dyskinesia
However, many experts have moved away from using TD as a broad diagnosis, calling it “classic tardive dyskinesia” instead. This refers specifically to involuntary, complex movements of the face and mouth with some limb, trunk, and pelvic involvement.
Mixed definitions of TD still exist across current literature, contributing to some ambiguity in its classification.
Other TDS are specific in their symptoms. Tardive tics, for example, only involve tics. Similarly, tardive tremor only involves shaking movements. Regardless of the uncertainty in defining TD symptoms, other TDS are more distinct.
Parkinsonism is a motor syndrome, a collection of related symptoms affecting muscle movement and flexibility. It gets its name from the similarity of its symptoms to those with Parkinson’s disease.
Symptoms
Both Parkinsonism and TD, especially TD under its broad definition, can feature repetitive and unusual muscle movements, such as:
- tremors
- muscle rigidity
- disrupted gait
Symptom onset in Parkinsonism is widely varied and depends on the underlying condition causing the syndrome. Onset can be immediate, such as in stroke, or may develop slowly in neurodegenerative conditions.
TD symptom development is usually delayed. It often occurs after long-term medication use.
Causes
Many different conditions can cause Parkinsonism, but it can also be caused by medication use. This form of Parkinsonism is called drug-induced Parkinsonism, or DIP.
DIP is usually caused by medications that are used to treat mental health disorders, especially antipsychotics, but also potentially from medications that are used to treat depression or anxiety.
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Treatment
Some forms of Parkinsonism can be cured. DIP, for example, usually resolves once the responsible medication is discontinued.
TD does not go away after medication stoppage. According to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR), a defining feature of TD is that symptoms persist longer than 4 weeks after drug discontinuation.
Dystonia is a neurological disorder as well as a feature in other conditions. Its symptoms include involuntary muscle contractions that torque the body and its parts into unusual positions and movements.
Symptoms
Dystonia can affect any part of the body. TD primarily affects the face, particularly the mouth area, though it can be seen in the limbs, trunk, or pelvis.
Dystonia symptoms stem from dysfunction in the basal ganglia of the brain, an area involved in movement and coordination control.
Causes
Like many movement disorders, the trigger for dystonia isn’t always identified.
Dystonia is often caused by conditions such as cerebral palsy, multiple sclerosis, or stroke. Brain damage, genetics, and other environmental factors may be involved.
Treatment
There’s no cure for dystonia or TD. Both involve supportive care that aims to manage symptoms, such as DBS and botulinum toxin (Botox) injections.
Medications can also be used to treat both TD and dystonia.
Tardive dyskinesia is a movement disorder caused by the long-term use of certain medications. It shares a variety of symptoms with other movement disorders, such as Parkinsonism and Tourette syndrome.
Some ambiguity exists in the definition of TD, but it remains a separate diagnosis from other similar conditions based on differences in symptoms’ presentation, underlying causes, and treatment options.
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