Cortical Morphometric Subclassification of Frontotemporal Lobar Degeneration

Abstract

BACKGROUND AND PURPOSE:Frontotemporal lobar degeneration (FTLD) is a primary neurodegenerative disease comprising 3 clinical subtypes: frontotemporal dementia (FTD), semantic dementia (SD), and progressive nonfluent aphasia (PNFA). The subdivision is primarily based on the characteristic clinical symptoms displayed by each subtype. We hypothesized that these symptoms would be correlated to characteristic patterns of brain atrophy, which could be indentified and used for subclassification of subjects with FTLD.

Putaminal Volume in Frontotemporal Lobar Degeneration and Alzheimer Disease: Differential Volumes in Dementia Subtypes and Controls

“…Putaminal atrophy on MR imaging may be potentially useful in clinical subtyping of FTLD, in combination with patterns of atrophy in other cortical and subcortical regions. 1,35 These results contrast with our previous study of bilateral caudate volume in FTLD, in which a clear gradient of atrophy, with volumes of controls ϭ AD Ͼ SD Ͼ PNFA Ͼ FTD, was consistent with the expected frontostriatal dysfunction in each subtype of FTLD and for AD and controls. Thus, the putamen seems less clearly implicated as a substrate in frontostriatal circuit dysfunction in FTLD.…”

Gray Matter Atrophy in Behavioral Variant Frontotemporal Dementia: A Meta-Analysis of Voxel-Based Morphometry Studies

“…Pathologically, bvFTD is associated with frontotemporal lobar degeneration [7] and is clinically characterized by progressive changes in personality, social comportment, and cognition [5,8]. Brain imaging techniques, such as positron emission tomography (PET) [9,10], functional MRI [11], structural regions of interest [12,13], and VBM technique [14,15], have long been used to understand the neuroanatomy and neuropathophysiology of this disease. Even brain imaging criteria has been proposed along with the clinical criteria that bvFTD is characterized by bilateral impairment in the frontal and/or temporal brain regions [16,17].…”

A Comparison Between Volumetric Data Generated by Voxel-Based Morphometry and Manual Parcellation of Multimodal Regions of the Frontal Lobe

“…Participants have been previously described. [19][20][21][22][23] All participants went through the standard investigation procedure at the memory clinic. Clinical diagnoses were determined at a multidisciplinary consensus conference with physicians, neuropsychologists, speech-language pathologists, and nurses.…”

“…However, in this study, we were not able to find significant atrophy in the anterior cingulate in FTD. 19 We hypothesized that the anatomic variability of this region caused a larger difference in volume than a potential reduction of volume caused by atrophy.…”

“…The masks were drawn for the 5 regions previously measured by manual tracing. 19 8) The regional masks were applied to the smoothed gray matter (sigma ϭ 2 mm) data of each subject with AFNI (open source software for neuroimaging data analysis, http://afni.nimh.nih.gov/) to obtain the mean attenuation of gray matter in the masked regions.…”