Longitudinal Patterns Of Brain Atrophy In Frontotemporal Lobar Degeneration Clinical Syndromes Compared With Alzheimer’s Disease (P4.018)

OBJECTIVE: To investigate grey (GM) and white matter (WM) volume contraction in patients with frontotemporal lobar degeneration (FTD) syndromes and Alzheimer’s disease (AD) using tensor based morphometry (TBM). BACKGROUND: Structural MRI is known to provide relevant information for the phenotypic characterization and diagnosis of FTD syndromes and can aid the differential diagnosis with AD. DESIGN/METHODS: T1-weighted MRI scans were obtained at baseline and follow-up (range interval: 12-36 months) from 7 patients with probable behavioural variant of frontotemporal dementia (bvFTD, age:60±7 ; CDR-SB:4±3), 7 patients with semantic variant of primary progressive aphasia (SV; age:65±8; CDR-SB:3±2), and 13 patients with probable AD (age:69±7; CDR-SB:5±1). TBM was used for image processing and statistical analysis. RESULTS: BvFTD patients showed a progression of GM atrophy in the orbitofrontal cortex, thalamus, middle and posterior cingulum, and angular gyrus bilaterally, and WM atrophy in the genu of the corpus callosum, posterior parahippocampal regions, brainstem and regions in the vicinity of the primary motor cortices. SV patients showed a progression of GM atrophy in the parahippocampal gyrus, posterior cingulum and thalamus bilaterally, and WM atrophy progression in the splenium of the corpus callosum and midbrain bilaterally. AD patients showed a progression of GM atrophy in the frontal gyrus, anterior and posterior cingulum, and hippocampus bilaterally, and WM atrophy in the entire corpus callosum and regions in the vicinity of the precentral gyri. CONCLUSIONS: Structural MRI is able to detect longitudinal changes in patients with FTD clinical syndromes and AD. The spread of atrophy (posteriorly in FTD and anteriorly in AD) is consistent with the evolution of cognitive deficits in these syndromes. Furthermore, in all patients WM atrophy progression involved the motor system. These patterns provide information about disease evolution in the FTD syndromes and AD that is of both clinical and neurobiological relevance. Study Supported by: Italian Ministry of Health (Grant #GR-2010-2303035).