A reader asks an expert about differential features distinguishing between early stages of tardive dyskinesia and motor tics.
Could you tell me about the differential features distinguishing between early stages of tardive dyskinesia (TD) and motor tics (particularly if the "tic" is NOT a simple repetitive movement)?DR BUCKLEY: This is a great question! The reality is that it can be extremely difficult to distinguish early and correspondingly mild TD from other motor expressions and disorders, both normal and abnormal (like tics). Age is a key consideration, since tics are more common in kids. Abnormal involuntary movements increase with age, with elderly people having abnormal involuntary movements as part of either dementing, neurologic, or other organic brain conditions--irrespective of whether these patients have been exposed to antipsychoitc medications.
It is important to evaluate potentially abnormal involuntary movements in the context of other clinical information. Thus, if the patient has a psychotic disorder and is/has been on antipsychotic medications, then that is a key consideration. Dosage and type of medicine are also important to take into account as well, since some antipsychotics (older more than new) are more apt to induce abnormal involuntary movements.
In the final analysis, these abnormal involuntary movements need to be carefully recorded and then reevaluated over time. That way, we can learn more about the likely cause and pattern of the motor effects. Obviously, if the clinician suspects that these abnormal involuntary movements are TD due to medications, then consideration of stopping the medicine and/or switching to a different one is another important aspect of the initial evaluation and management.
Click here for more info on TD and to download the AIMS (Abnormal Involuntary Movement Scale).