Stereotypical movements and frontotemporal dementia.

Stereotypical movements are characteristic of autism or mental retardation but can also occur in patients with dementia, particularly frontotemporal dementia (FTD). In this study, we administered the Abnormal Involuntary Movement Scale (AIMS) to 18 patients with FTD and to 18 patients with the most common form of dementia, Alzheimer's disease (AD). The AIMS scores were gathered at the initial presentation of patients who had not received antipsychotic medications. Compared to the AD patients, the FTD patients had significantly more stereotypical movements, including frequent rubbing behaviors and some self-injurious acts. All the FTD patients with stereotypical movements had compulsive-like behaviors, suggesting a similar pathophysiologic cause, and most had a decrease in their stereotypical movements with the administration of sertraline, a serotonin selective reuptake inhibitor.