A 50 year old woman with schizophrenia who has been taking a antipsychotic drug for the past 3 years has begun to show involuntary chewing and lip-smacking movements. Which can be the most likely possibility?
## **Core Concept**
The question tests understanding of a common side effect associated with long-term use of antipsychotic medications, specifically **tardive dyskinesia**. Tardive dyskinesia is a neurological disorder characterized by involuntary, repetitive body movements that can occur in patients taking neuroleptic drugs for an extended period.
## **Why the Correct Answer is Right**
Tardive dyskinesia often presents with **orofacial movements** such as lip smacking, puckering, and tongue protrusion, which match the symptoms described in the question. This condition is a result of chronic blockade of dopamine receptors in the brain, particularly D2 receptors, which are involved in the regulation of movement. The symptoms of tardive dyskinesia can be irreversible and are a significant concern in the long-term management of patients with schizophrenia.
## **Why Each Wrong Option is Incorrect**
- **Option A:** While extrapyramidal side effects (EPS) such as dystonia, parkinsonism, and akathisia can occur with antipsychotic use, they typically present early in treatment and have different symptomatology than tardive dyskinesia.
- **Option B:** Neuroleptic malignant syndrome (NMS) is a life-threatening neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic medication. It presents with fever, muscle rigidity, autonomic dysfunction, and altered mental status, not with involuntary chewing and lip-smacking movements.
- **Option C:** Akathisia is a type of EPS characterized by subjective feelings of restlessness and an urge to move, often manifesting as pacing or fidgeting. It does not typically present with the specific orofacial movements described.
## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that **tardive dyskinesia** is often **irreversible** and its management may involve changing the antipsychotic medication or using valbenazine or deutetrabenazine, which are specifically approved for the treatment of tardive dyskinesia. Early recognition and intervention are crucial.
## **Correct Answer:** D. Tardive dyskinesia.