How can I distinguish tardive dyskinesia from chorea?

Tardive dyskinesia (TD) is a movement disorder resulting from ongoing use of dopamine receptor blocking agents (DRBAs) – ie, antipsychotics – leading to involuntary movements that are usually repetitive and frequently involving the face and mouth. Chorea can also involve the face and oral region but typically is not limited to those areas. Choreiform movements are less patterned, more rapid, and more unpredictable than TD.

Specific Symptoms

More specific TD symptoms may include chewing movements, tongue protrusion, lip smacking, grimacing, and/or lip pursing, and in some cases, may involve repetitive movements of the limbs, trunk, and head, according to Danielle Thordarson, MD, a neurologist at the Movement Disorders Clinic at UCLA’s David Geffen School of Medicine.

“TD typically emerges after prolonged treatment with DRBAs, hence the name tardive, though less frequently short-term use can cause TD. The symptoms tend to persist and remain permanent; however, it is thought that stopping the causative drug earlier increases the likelihood of symptoms diminishing over time,” she explained. “Alternatively, acute to subacute extrapyramidal side effects caused by DRBAs including akathisia, drug-induced Parkinsonism, and dystonia reliably resolve with discontinuation of the offending medication.”

Chorea involuntary movements tend to flow from one body part to another. “The condition is a descriptive term for a movement that can be caused by a number of different mechanisms, including neurodegenerative processes (such as Huntington's disease), autoimmune conditions, postinfectious causes, paraneoplastic syndromes, vascular/stroke, or it can be drug-induced,” said Dr. Thoradarson. When drug-induced, dopaminergic or antidopaminergic drugs, anticonvulsants, or other medications may be involved.

Clinical Considerations for Differential Diagnosis

When it comes to diagnosing, there are a few clinical considerations that can help differentiate the two conditions.

In addition to reviewing the patient's full medication history, consider that “TD most commonly results from dopamine blockade from antipsychotic medications, but it is important to consider that TD can result from other medications with dopamine blocking properties as well, such as metoclopramide, chlorpromazine, and amoxapine,” said Dr. Thoradarson.

“If the patient has not had any exposure to dopamine blocking agents at any point,” noted Dr. Thoradarson, then “they cannot have tardive dyskinesia,” she emphasized. If they have had such medications, clinicians can assess the characteristics of the patient’s movements.

“Chorea is a description of a phenomenology or type of movement, whereas tardive dyskinesia is a specific diagnosis…. While tardive dyskinesia and chorea can have overlapping features, TD is typically repetitive and stereotyped, whereas chorea should be less predictable,” she explained.

In ambiguous cases, Dr. Thoradarson recommends referral to neurologist or a movement disorder specialist. “Making note of symptom acuity and recent medication changes will aid in interim management while awaiting consultation.”