Neural correlates of behavioural symptoms in behavioural variant frontotemporal dementia and Alzheimer's disease: Employment of a visual MRI rating scale

Abstract

Frontotemporal dementia (FTD) patients often present with severe behavioural disturbances and concomitant lack of insight. The underlying neural correlates of these disturbances are mostly attributed to prefrontal cortex dysfunction, but are still poorly understood.ObjectivesThe current study explores whether a simple visual magnetic resonance imaging (MRI) rating scale in combination with the Frontal System Behaviour Scale (FrSBe) can be used to identify the prefrontal correlates of behavioural symptoms in behavioural variant frontotemporal dementia (bvFTD) and Alzheimer's disease (AD).MethodsForty-eight patients with a clinical diagnosis of bvFTD and AD participated in the study. Their behavioural profiles were assessed using the Frontal System Behaviour Scale (FrSBe) and cross-correlated to the atrophy of the sub-regions in the prefrontal cortex using a 5-point visual rating scale of MRI scans.ResultsPatients with bvFTD showed higher incidence of behavioural disturbances than AD with apathy being the most significant. BvFTD patients also showed the highest incidence of atrophy in the orbital frontal cortex and this atrophy was correlated with the apathetic features.ConclusionsEmployment of a simple visual MRI rating scale can be used in combination with a behavioural screening test to identify reliably the behavioural symptoms in bvFTD and AD. These findings will inform the diagnostic accuracy of the neural correlates of behavioural dysfunction in bvFTD in the future.

Social Cognition Deficits Are Pervasive across Both Classical and Overlap Frontotemporal Dementia Syndromes

“…Disinhibition was found in almost the same proportion across all the subtypes. While disinhibited behaviour is considered a typical feature of BvFTD [ 48 , 49 , 50 ], a few studies report disinhibition also with SD, and to a lesser extent in PNFA patients [ 46 , 51 ]. The frequency of disinhibition in overlap syndromes, i.e., FTD-ALS and FTD-PSP, has not been previously reported.…”

Frontostriatal grey matter atrophy in amyotrophic lateral sclerosis A visual rating study

“…This builds upon previous research that showed the OFC was the only area where ALS patients had higher atrophy, 11 and reoccurrence of atrophy in this area in FTD when compared to AD. 9 , 10 Furthermore, this area has been shown to have greater grey matter atrophy in patients with FTD and ALS-FTD. 18 Our findings point to pathological changes in ALS associated with specific regions of the OFC, which likely map onto the ALS-FTD subtypes.…”

“…Previous research using MRI rating scales has shown greater atrophy in the medial prefrontal cortex and orbitofrontal cortex in behavioural variant FTD (bvFTD) patients compared to Alzheimer’s Disease patients and controls. 9 , 10 Further, in terms of the ALS-FTD spectrum, visual atrophy ratings showed that patients with ALS-FTD and bvFTD had higher orbitofrontal cortex, anterior cingulate cortex, motor cortex and anterior temporal lobe atrophy compared to controls. 10 Notably, in this same study, patients with ALS only significantly differed to controls for the orbitofrontal cortex.…”

Mouse models of frontotemporal dementia: A comparison of phenotypes with clinical symptomatology

“…Interestingly, recent studies have elucidated commonalities in the neural substrates of behavioral changes in FTD. For example, both disinhibited (Hornberger et al, 2011) and apathetic (Go et al, 2012) behaviors relate to atrophy in the orbitofrontal cortex, one of the core sites of early pathology (Seeley, 2008).…”