Drug-induced tardive motor syndromes

Drug-induced tardive motor syndromes (TMS) is a group of disorders, characterized by involuntary movements of the tongue, face, lips, trunk and extremities, occurring after long-term exposure to a variety of pharmacological agents, mostly neuroleptics. The diagnosis of TMS requires exposure to dopamine receptor blocking agents for a period at least of 3 months, although for people over 60 years old the necessary exposure period is limited to 1 month. The exact pathophysiology still remains obscure. The aim of this article is to review the phenomenology, epidemiology and treatment options of the TMS, as clinically distinct movement disorders. TMS include tardive dyskinesia, which is the most common movement disorder, tardive dystonia, tardive akathisia, tardive Tourettism, tardive tremor and tardive myoclonus as well as some specific syndromes less often presented such as Pisa, Meige and Rabbit syndromes. Prevention remains the cornerstone in good clinical practice. Preventive approach requires thorough diagnostic process with frequent reviews in order to determine the necessity of use and dosing of neuroleptic treatment. Clinical vigilance for early detection of signs of TMS as well as recording of early extrapyramidal side-effects in the patient's history is needed, as these may predict the occurrence of TMS. In case of occurrence of TMS, gradual discontinuation of the offending agent is required. Therapeutic interventions include the administration of the following agents: atypical antipsychotics (mainly clozapine), benzodiazepines, vitamin E, reserpine, tetrabenazine, anticholinergics, botulinum toxin A. The early management of TMS is crucial for the patients' better clinical outcome and improved quality of life.