What is tardive dyskinesia?

What is Tardive Dyskinesia

Tardive dyskinesia (TD) is an involuntary movement disorder typically affecting the orofacial region but potentially involving any body part, associated with long-term use of dopamine receptor-blocking agents (antipsychotics and certain other medications). 1

Clinical Characteristics

TD manifests as abnormal, involuntary, irregular, repetitive movements that are purposeless in nature:

• Orofacial involvement is most common, including involuntary movements of the tongue, face, mouth, or jaw 2
• Limb and truncal movements may occur, often appearing choreoathetotic (writhing, dance-like) in character 2, 3
• Symptoms include facial grimacing, rhythmic tongue protrusion, lip smacking, and involuntary movements of extremities 2

Subtypes and Related Conditions

Beyond classic TD, related tardive syndromes include:

• Tardive dystonia: characterized by slow movements along the body's long axis culminating in spasms, potentially including facial spasms 4
• Tardive akathisia: motor restlessness with feelings of anxiety, agitation, inability to sit still, pacing, and foot tapping 3

Causative Agents

TD develops from exposure to dopamine receptor-blocking medications:

• Antipsychotics (both typical and atypical, though typical agents carry higher risk) are the primary culprits 1
• Metoclopramide carries an FDA black box warning for TD risk, particularly with use exceeding 12 weeks 2
• Other medications with antidopaminergic activity used for nausea or gastrointestinal dysfunction can cause TD with extended use 3

Critical Features

The disorder is often irreversible, making prevention paramount 1, 2:

• TD may persist even after medication discontinuation 1
• The risk of permanence increases with duration of exposure 5
• In some patients, symptoms may lessen or resolve after stopping the offending agent, but there is no guarantee 2

Prevalence and Risk Factors

• Overall prevalence: approximately 20% of neuroleptic-treated patients develop TD 3
• High-risk populations include the elderly (substantially higher rates), women, patients with affective disorders, and those with diabetes 3, 5
• Youth are particularly vulnerable: up to 50% of youth receiving neuroleptics may experience some form of tardive or withdrawal dyskinesia 4, 1
• Total drug exposure is positively correlated with TD risk 3

Diagnostic Criteria

TD diagnosis requires:

• Development during exposure to or withdrawal from neuroleptics 6
• History of neuroleptic use for at least 3 months (or 1 month in patients ≥60 years old) 6
• Presence of characteristic involuntary movements that are out of the patient's control 5

Pathophysiology

While the exact mechanisms remain incompletely understood, altered dopaminergic function likely plays a central role in TD pathogenesis 3, 6.