Sheela Kumari R MSc, Presenter: Nothing to Disclose

 The frontal variant FTD is defined by the presence of behavioural manifestations such as apathy, disinhibition and executive disinhibition , but their neuroanatomical correlates are still not clearly defined. 

Patients with a clinical diagnosis of FTD in the SCTIMST Memory Clinic were included in the study. Study was performed after getting approval from the Institutional Ethics Committee. We administered Frontal system behavioural scale (FrSBe) to 20 patients with FTD and 20 normal control (NC) subjects. All the subjects were underwent a high resolution T1 weighted Volumetric Magnetic Resonance Imaging (MRI) sequence in 1.5 Tesla Seimens scanner. Voxel Based Morphometry (VBM) was used to explore the pattern of GM atrophy in apathy and disinhibition profiles as measured by FrSBe. By using VBM, subject brains were segmented into GreyMatter (GM), White Matter (WM) and Cerebrospinalfluid(CSF). Segmented images were then smoothed with an isotropic Guassian kernel of 12 mm Full Width Half Maximum (FWHM). The smoothed images were used to compare the GM density between FTD patients and controls. A two sample t test comparison by setting up a voxel-wise General Linear Model (GLM) was performed between FTD and NC to provide an overall indicator of pattern atrophy in FTD patients. For multiple comparison age, sex and TIV were included as covariates in the design matrix. Apathy and disinhibition scores were entered as disease factors in the design matrix. A level of significance of p<0.001, uncorrected was accepted for the multiple comparison of whole brain analysis.

Compared with a group of controls, FTD patients revealed a wide spread atrophy in the frontal and the anterior temporal lobes. Apathy profile in FTD is correlated with atrophy in right prefrontal cortex, right rectal gyrus, anterior cingulate and right rolandic operculum regions. Disinhibited profile is correlated with atrophy in right Heschl gyrus, right hippocampus , right insula and olfactory regions. 

Atrophy in frontal and temporal regions associated with apathetic and disinhibited profile. The correlation analysis between regional atrophy and corresponding symptoms in FTD was successfully validated by VBM.  

 Our study may help in the better understanding of the neural correlates of this dreaded dementing disease as well as facilitate the understanding of human brain. 

R, S, Neural Correlates of Apathy and Disinhibition in FrontoTemporal Dementia.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017364.html