Antipsychotic medication can disrupt the function of extrapyramidal neurons. This can result in disfiguring side effects, such as tardive dyskinesia, a syndrome characterized by tremors in the extremities and facial muscles. The atypical antipsychotics, a new class of medication, have now become popular because they produce fewer extrapyramidal side effects (e.g., restlessness, tremor, and muscular stiffness).