Classically, TD manifests as orofacial hyperkinesia involving irregular movements of low frequency and variable amplitude. Prototypical features of TD include repetitive movements of the jaw, lips, and tongue (rabbit syndrome), trunk, and extremities that start during treatment with neuroleptics and persist for ≥ 4 weeks despite discontinuation or medication dose reduction. However, many other conditions cause abnormal movements that resemble TD and should be ruled out, making TD a diagnosis of exclusion. A complete neurologic and pharmacologic patient history should be considered, with awareness of higher-risk groups, such as female patients, older patients, patients with diabetes mellitus, and patients with neurodevelopmental and neurogenerative disorders.
A sensation of extreme inner restlessness describes akathisia, another potential side effect of antipsychotic or antidopaminergic medications. Patients with akathisia tend to experience discomfort when asked to sit still. Unlike TD, akathisia typically occurs within the first few days of treatment with anti-dopaminergic agents. Patients can be assessed for akathisia using the Hillside Akathisia Scale.
Exertion-induced attacks of dystonia affecting the extremities are associated with paroxysmal exertion-induced dyskinesia (PED), which is not typically associated with neuroleptic medications.
Parkinsonism is the generalized slowing of movement without weakness associated with antipsychotics, particularly in older adults, and Parkinson's disease. The antipsychotic medications that cause TD may alternatively cause drug-induced parkinsonism through dopamine blockade.
Learn more about the workup of TD.
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Cite this: Matthew Swan, James Robert Brasic. Fast Five Quiz: How Much Do You Know About Tardive Dyskinesia? - Medscape - Apr 22, 2022.