The CBI‐R detects early behavioural impairment in genetic frontotemporal dementia

Abstract

Introduction Behavioural dysfunction is a key feature of genetic frontotemporal dementia (FTD) but validated clinical scales measuring behaviour are lacking at present. Methods We assessed behaviour using the revised version of the Cambridge Behavioural Inventory (CBI‐R) in 733 participants from the Genetic FTD Initiative study: 466 mutation carriers (195 C9orf72, 76 MAPT, 195 GRN) and 267 non‐mutation carriers (controls). All mutation carriers were stratified according to their global CDR plus NACC FTLD score into three groups: asymptomatic (CDR = 0), prodromal (CDR = 0.5) and symptomatic (CDR = 1+). Mixed‐effects models adjusted for age, education, sex and family clustering were used to compare between the groups. Neuroanatomical correlates of the individual domains were assessed within each genetic group. Results CBI‐R total scores were significantly higher in all CDR 1+ mutation carrier groups compared with controls [C9orf72 mean 70.5 (standard deviation 27.8), GRN 56.2 (33.5), MAPT 62.1 (36.9)] as well as their respective CDR 0.5 groups [C9orf72 13.5 (14.4), GRN 13.3 (13.5), MAPT 9.4 (10.4)] and CDR 0 groups [C9orf72 6.0 (7.9), GRN 3.6 (6.0), MAPT 8.5 (13.3)]. The C9orf72 and GRN 0.5 groups scored significantly higher than the controls. The greatest impairment was seen in the Motivation domain for the C9orf72 and GRN symptomatic groups, whilst in the symptomatic MAPTgroup, the highest‐scoring domains were Stereotypic and Motor Behaviours and Memory and Orientation. Neural correlates of each CBI‐R domain largely overlapped across the different mutation carrier groups. Conclusions The CBI‐R detects early behavioural change in genetic FTD, suggesting that it could be a useful measure within future clinical trials.

Measuring Change over Time on Cognitive Screening Measures: An Evaluation of the Psychometric Properties of ACE-III, CBI-R, and EMQ for the Purpose of Dementia Screening

“…Screening measures are designed to provide a probability ratio for the likelihood of a dementia diagnosis. While screening measures, such as ACE-III, CBI-R, and EMQ-R, all have established validity for identifying people with dementia [6][7][8], the extent to which they are able to validly and reliably assess early cognitive change and/or change in cognitive status over time has not been established. For example, there are increased efforts to provide early diagnosis of dementia, and this means that people are being assessed earlier in the course of the disease, sometimes before phenotypical cognitive and/or behavioural difficulties are evident [9].…”