Deformation-based morphometry reveals brain atrophy in frontotemporal dementia.

OBJECTIVE: To compare deformation-based maps of local anatomical size between subjects with frontotemporal dementia (FTD) and healthy subjects to identify regions of the brain involved in FTD.
DESIGN: Structural magnetic resonance images were obtained from 22 subjects with FTD and 22 cognitively normal, age-matched controls. We applied deformation-based morphometry and compared anatomy between groups using an analysis of covariance model that included a categorical variable denoting group membership and covaried for head size.
SETTING: University of California, San Francisco, Memory and Aging Center, and the San Francisco Veterans Affairs Medical Center. PATIENTS: Twenty-two subjects with FTD and 22 cognitively normal, age-matched controls.
INTERVENTIONS: Neurological, neuropsychological, and functional evaluations and magnetic resonance imaging. MAIN OUTCOME MEASURE: Deformation maps of local anatomical size.
RESULTS: Patients with FTD showed extensive, significant atrophy of the frontal lobes, affecting both gray matter and white matter. Atrophy of similar magnitude but less significance was observed in the anterior temporal lobes. The subcortical and midbrain regions, particularly the thalamus, pons, and superior and inferior colliculi, showed strongly significant atrophy of smaller magnitude.
CONCLUSIONS: We confirmed frontal and anterior temporal gray matter atrophy in FTD. The observed white matter loss, thalamic involvement, and midbrain atrophy are consistent with pathological findings in late-stage FTD. Dysfunction of ventral-frontal-brainstem circuitry may underlie some of the unique clinical features of FTD.