Tardive dyskinesia shares features with other movement disorders, such as Tourette syndrome and drug-induced Parkinsonism. But differences in presentation, treatment, and underlying causes set these conditions apart as separate diagnoses.

Tardive dyskinesia (TD) is an involuntary movement disorder that develops as a side-effect of 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. 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 more frequently than girls. Its exact causes are unknown, but genetics, changes in brain function and structure, and environmental factors are thought to play a role.

TD is specifically caused by the use of dopamine receptor antagonists, medications that block dopamine receptors in the body. It affects women more than men and is more common with age.

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.

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 also has childhood onset. But it features only motor or vocal tics — not both, like in Tourette syndrome.

TD remains a diagnosis separate from these tic disorders for the same reasons it’s separate from Tourette syndrome.

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 was once considered synonymous with TDS due to the variety of symptoms possible in its presentation. TD can include symptoms such as tics and tremors, for example, as well as other nonspecific involuntary movements.

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.

Despite differences in symptoms, TD and TDS share underlying causes and treatment approaches.

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. In fact, Parkinson’s disease is the leading cause of Parkinsonism.

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

Parkinsonism, however, is also associated with slowed or delayed movements, unlike the quick, rapid movements often seen in TD.

Symptom onset in Parkinsonism is widely varied and depends on the underlying condition causing the syndrome. Onset can be immediate, such as in brain injury, or may develop slowly in neurodegenerative conditions.

TD symptom development is always delayed. It occurs after long-term medication use.

Causes

Many different conditions can cause Parkinsonism, but it can also be caused by medication use like TD. This form of Parkinsonism is called drug-induced Parkinsonism, or DIP.

According to a 2018 review, DIP symptom onset is often much sooner than TD, occurring within hours or weeks of starting a medication. TD’s onset is more delayed, often taking several months or longer to emerge.

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.

Causes

Like many movement disorders, the exact causes of dystonia aren’t fully understood. Its symptoms stem from dysfunction in the basal ganglia of the brain, an area involved in movement and coordination control.

Brain damage, genetics, and other environmental factors may be involved, but many people have no identifiable cause of dystonia.

Tardive dystonia falls under the category of tardive syndromes. Some consider it a form of TD, but it’s differentiated by the severity of involuntary movements.

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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