Disinhibition in Frontotemporal Dementia and Alzheimer’s Disease: A Neuropsychological and Behavioural Investigation

Abstract

Objective:Cognitive tests of inhibitory control show variable results for the differential diagnosis between behavioural variant of Frontotemporal Dementia (bvFTD) and Alzheimer’s disease (AD). We compared the diagnostic accuracies of tests of inhibitory control and of a behavioural questionnaire, to distinguish bvFTD from AD.Methods:Three groups of participants were enrolled: 27 bvFTD patients, 25 AD patients, and 24 healthy controls. Groups were matched for gender, education, and socio-economic level. Participants underwent a comprehensive neuropsychological assessment of inhibitory control, including Hayling Test, Stroop, the Five Digits Test (FDT) and the Delay Discounting Task (DDT). Caregivers completed the Barratt Impulsiveness Scale 11th version (BIS-11).Results:bvFTD and AD groups showed no difference in the tasks of inhibitory control, while the caregiver questionnaire revealed that bvFTD patients were significantly more impulsive (BIS-11: bvFTD 76.1+9.5, AD 62.9+13, p < .001).Conclusions:Neuropsychological tests of inhibitory control failed to distinguish bvFTD from AD. On the contrary, impulsivity caregiver-completed questionnaire provided good distinction between bvFTD and AD. These results highlight the current limits of cognitive measures of inhibitory control for the differential diagnosis between bvFTD and AD, whereas questionnaire information appears more reliable and in line with clinical diagnostics.

Relationship between elevated impulsivity and cognitive declines in elderly community-dwelling individuals

“…Impulsivity is typically defined as a predisposition toward rapid, unplanned actions responding to internal or external stimuli without regard for the consequences they might bring to oneself or to the others 5 . Impulsivity is also recognized as an intermediate phenotype of various behavioral abnormalities, as well as a phenotype that sometimes accompanies the progression of various types of dementia, including frontotemporal dementia (FTD) [6][7][8] and Alzheimer's disease (AD) [9][10][11][12] . With the progression of dementia, cognitive functions decline in a variety of domains, and behavioral and psychological symptoms of dementia (BPSD), including impaired impulse control, are exhibited [11][12][13][14] .…”

Cognitive and behavioural inhibition deficits in neurodegenerative dementias

“…In summary, disinhibition is frequent in both bvFTD and AD, with greater social disinhibition in bvFTD and comparable generalised impulsivity in both diseases ( Paholpak et al., 2016 ). However, using the Barratt Impulsiveness Scale (BIS-11), Mariano et al (2020) showed higher scores of impulsive behaviour in bvFTD patients than in AD patients and controls, but not with neuropsychological tests. Dealing with these behaviours is a hard and heavy challenge for caregivers, with cases of personal neglect or reduced self-care (Diogenes syndrome) ( Finney & Mendez, 2017 ), sexists comments, overt aggression, and in more extreme situations, they can result in criminal charges or pathological gambling ( Tondo et al., 2017 ).…”

Language in Behavioral Variant Frontotemporal Dementia: Another Stone to Be Turned in Latin America

“…LA bvFTD patients have impaired phonemic fluency relative to healthy controls ( 56 – 58 , 60 , 68 – 70 , 72 , 74 , 75 ). This has been observed for both Spanish-speaking ( 57 , 60 , 74 , 75 ) and Portuguese-speaking ( 68 , 72 ) cohorts, across different age groups (mean age varying from 64.4 to 70.2 years old) and education levels (years of education ranging from 10.8 to 16.0 years). Non-significant differences were reported by Torralva et al ( 62 ), although these results came from a smaller sample with higher MMSE scores than those reported in other studies.…”