Brain atrophy in frontotemporal dementia

Objective-To evaluate the pattern of regional brain atrophy in patients with frontotemporal dementia by comparing it with that in patients with Alzheimer's disease and normal controls. Methods-Fourteen patients with frontotemporal dementia, 13 with moderate, and 33 with mild Alzheimer's disease, and 31 controls were studied. Atrophy was evaluated with linear measures in the anterior brain, medial temporal lobe, and hippocampal formation regions using MRI. Results-Patients with frontotemporal dementia had greater atrophy in the anterior brain regions than patients with Alzheimer's disease or controls. Atrophy of the hippocampal formation, which best discriminates Alzheimer's disease from controls, was present also in patients with frontotemporal dementia. By contrast, atrophy of the medial temporal lobe, which is also present in Alzheimer's disease, was absent in frontotemporal dementia. Conclusion-A pattern of atrophy in the frontal lobes and hippocampal formation with sparing of the medial temporal lobe might be distinctive of frontotemporal dementia. Hippocampal involvement might not be specific for Alzheimer's disease and specific patterns of atrophy might be distinctive of some forms of degenerative dementia.