Types of Drug-induced Movement Disorders

Drug-induced Movement Disorders

Drug-induced dystonia, a twisting movement or abnormal posture (or a combination thereof) may manifest as acute or tardive involuntary limb movements, facial grimacing, cervical dystonia, oculogyric crisis, rhythmic tongue protrusion, bulbar speech, trismus, and, rarely, stridor and dyspnea. The acute form typically occurs within 2 to 5 days after initiation of treatment with a DRBD.

The features of idiopathic Parkinson disease comprise the same primary characteristics of drug-induced parkinsonism: rest tremor, bradykinesia, rigidity, and postural instability. Lack of recognition is a primary impediment to treatment, as cessation of the causal agent may lead to resolution symptoms in drug-induced parkinsonism.2 In some patients, however, symptoms may endure for 18 months or even longer and in some, the parkinsonism is permanent.

The stereotypies of classic tardive dyskinesia (i.e., OBLD) are characterized by well-coordinated continual movements of the mouth, tongue, jaw, and cheeks and may include lip smacking, cheek puffing, and tongue thrusting. Jaw movements may be lateral or may resemble chewing motions. The tongue movements may be writhing or twisting (choreoathetoid). In addition to having OBLD, patients treated with antipsychotic drugs may also have trunk movements, which are typically in the form of pelvic thrusting or trunk twisting or choreoathetotic or flicking of the extremities.

Akathisia (literally meaning, an inability to sit) manifests as an inner feeling of restlessness and stereotypic movements, such as marching in place and crossing and uncrossing the legs while sitting. Akathisia is the only drug-induced movement disorder that does not have an idiopathic counterpart.

Neuroleptic malignant syndrome is an abrupt, life-threatening, idiosyncratic response that occurs in approximately 0.2% of patients after they receive a therapeutic dose of a DRBD. The symptoms include hyperthermia (> 38°C), muscle rigidity, and autonomic dysregulation.