Neuropsychiatric and behavioral symptom clusters in frontotemporal dementia.

Background: Non-Alzheimer's disease dementias, including frontotemporal dementia (FTD) can be difficult to characterize due to the predominance of distinct behavioral and neuropsychiatric symptoms. Widely used measurement tools lack structure and objectivity.

Objective: The purpose of this study was to use systematic direct observation of neuropsychiatric and behavioral symptoms, via the Neurobehavioral Rating Scale (NBRS), to characterize clusters of behavioral and neuropsychiatric symptoms in FTD and examine how selected symptom clusters correlate with structural neuroimaging.

Methods: We performed a factor analysis on the NBRS data from 172 patients with FTD and examined the neural correlates of the selected symptom clusters in a subsample of 67 patients.

Results: Six factors accounted for 56% of total variance across NBRS item scores: Apathy/Blunting, Agitation/Disinhibition, Cognitive/Language, Planning/Insight, Anxiety/Lability, and Psychosis. Symptom clusters showed significant associations with specific regions of cortical thinning: Agitation/Disinhibition with bilateral frontal regions, and Cognition/Language with the left bank of the superior temporal sulcus and supramarginal regions.

Conclusions: The selected symptom clusters associated with known regions of atrophy in FTD. The NBRS is an effective observational measure that may extend characterization and understanding of FTD.