Utility of the Japanese version of the Clinical Dementia Rating? plus National Alzheimer's Coordinating Centre Behaviour and Language Domains for sporadic cases of frontotemporal dementia in Japan

Background: We aimed to validate the Clinical Dementia Rating (CDR (R)) dementia staging instrument plus the National Alzheimer's Coordinating Centre Behaviour and Language Domains (CDR (R) plus NACC FTLD) for use in clinical settings in Japan and in the Japanese language.Methods: This prospective observational study enrolled 29 patients with frontotemporal dementia (FTD) and 21 patients with Alzheimer's disease (AD) dementia from the Departments of Psychiatry at Osaka University Hospital and Asakayama General Hospital and the Brain Function Centre at Nippon Life Hospital. CDR (R) plus NACC FTLD, CDR (R), Mini-Mental State Examination (MMSE), Western Aphasia Battery (WAB), Neuropsychiatric Inventory-plus (NPI-plus), Stereotypy Rating Inventory (SRI), and frontal behavioural symptom scores obtained from items of NPI-plus and SRI, were conducted to assess inter- and intra-rater reliability, validity, and responsiveness. We performed receiver operating characteristic (ROC) curve analysis to evaluate the discriminating power of the Behaviour/Comportment/Personality (BEHAV) and Language (LANG) domains of the CDR (R) plus NACC FTLD and the MEMORY domain of the CDR (R) in patients AD dementia and FTD.Results: The CDR (R) plus NACC FTLD showed good inter- and intra-rater reliabilities. In patients with FTD, the BEHAV domain of the CDR (R) plus NACC FTLD was significantly correlated with all clinical measures except for the SRI total score, while the LANG domain of the CDR (R) plus NACC FTLD was significantly correlated with the MMSE and the WAB-Aphasia quotient. In addition, the CDR (R) plus NACC FTLD sum of boxes significantly changed after 6 months and after 1 year. ROC curve analysis showed that the BEHAV and LANG domains of the CDR (R) plus NACC FTLD distinguished between patients with AD dementia and FTD better than the MEMORY domain of the CDR (R).Conclusions: This study validated the Japanese version of the CDR (R) plus NACC FTLD with good reliability, validity, and responsiveness.