Tardive Syndrome (TS) Drug induced movement disorders

Tardive Syndrome (TS) Drug induced movement disorders

Tardive syndromes are a group of hyperkinetic and hypokinetic movement disorders that occur after some delay following exposure to dopamine receptor blocking agents such as antipsychotic and anti-emetic drugs.

Dopamine receptor-blocking antipsychotics, first introduced into clinical practice in 1952, were hailed as a panacea in the treatment of a number of psychiatric disorders. However, within 5 years, this notion was to be shattered by the recognition of both acute and chronic drug-induced movement disorders which can accompany their administration. Tardive syndromes, denoting the delayed onset of movement disorders following administration of dopamine receptor-blocking (and also other) drugs, have diverse manifestations ranging from the classic oro-bucco-lingual dyskinesia, through dystonic craniocervical and trunk posturing, to abnormal breathing patterns. Although tardive syndromes have been an important part of movement disorder clinical practice for over 60 years, their pathophysiologic basis remains poorly understood and the optimal treatment approach remains unclear.

Tardive syndrome (TS) is a group of movement disorders caused by the long-term use of dopamine receptor blocking agents. The phenotypic presentation of TS is diverse, ranging from the most well-characterized symptom of tardive dyskinesia to other symptoms, including dystonia, akathisia, myoclonus, parkinsonism, tremor, and tics. These tardive symptoms are distinct not only in their phenomenology but also in their clinical outcomes. However, our knowledge of the pathophysiology and management of TS is almost exclusively based on tardive dyskinesia. First-generation antipsychotics have a higher risk of inducing TS and have largely been replaced by second-generation antipsychotics with a lower risk of TS. However, patients with off-label use of second-generation antipsychotics are still at risk of developing TS. Thus, the management of TS remains a challenging and important issue for physicians. In this review, we update the information on the epidemiology, phenomenology, and treatment of TS from the perspective of the specific form of TS.

The severity of Tardive Syndrome ranges from mild to disabling or even life-threatening. There is a wide range of recognized tardive phenomenologies that may occur in isolation or in combination with each other. These phenomenologies include stereotypy, dystonia, chorea, akathisia, myoclonus, tremor, tics, gait disorders, parkinsonism, ocular deviations, respiratory dyskinesia, and a variety of sensory symptoms. Recognition of the various tardive phenomenologies may not only lead to early diagnosis but also to appropriate therapeutic intervention.

TS is diverse not only in its phenomenology but also in its clinical outcomes. The pathophysiology of the syndrome is still unclear and warrants further research. Future studies including patients with well-classified phenomenology may provide additional insights into the understanding of the disorder as well as treatment.