Manifestations of tardive dyskinesia (TD) can include a variable mixture of orofacial dyskinesia, athetosis, dystonia, chorea, tics, and facial grimacing. The symptoms involve the mouth, tongue, face, trunk, or extremities. Tardive tremor has also been rarely described.
A number of TD variants or subtypes have been described based on the type of involuntary movements that predominate in these conditions, including the following:
- Tardive dystonia
- Tardive akathisia
- Tardive tics
- Tardive myoclonus
- Tardive stereotypy
- Tardive tremor
- Tardive oral pain syndromes
The onset of TD is insidious and typically occurs while the patient is receiving an antipsychotic drug. In addition, it is common for TD to first appear after a reduction in dose, after switching to a less potent antipsychotic drug, or following discontinuation of an antipsychotic drug.
Although once considered a persistent or permanent condition, TD is often reversible.
The diagnosis of TD is based on the presence of dyskinetic or dystonic involuntary movements, a history of at least one month of antipsychotic drug treatment, and the exclusion of other causes of abnormal movements.
TD should be distinguished from other extrapyramidal syndromes, including:
- Wilson disease
- Huntington disease
- Akathisia
- Acute dyskinesia
- Stereotypies associated with chronic schizophrenia, autism, and severe mental retardation
- Spontaneous orofacial dyskinesia
- Meige syndrome
- Blepharospasm
- Oromandibular dystonia