Citations

BackgroundThe six domain standard Clinical Dementia Rating Scale (CDRstd) has been successful for staging patients with the clinical syndrome of probable Alzheimer's disease (AD). The CDRstd does not specifically address language dysfunction or alteration in personality and social behaviors which are prominent in behavioral variant frontotemporal dementia (bvFTD) and primary progressive aphasia (PPA).ObjectiveTo determine the value of adding domains of Language (LANG), and Behavior, Comportment, and Personality (BEHAV) to the CDRstd for the evaluation of patients with bvFTD and PPA.MethodsTwo new domains, LANG and BEHAV, were constructed to parallel the six domains sampled in the CDRstd. Clinical and neuropsychological test data were obtained from the National Alzheimer's Coordinating Center. The dataset contained information on 2550 probable AD, 88 vascular dementia, 281 dementia with Lewy body, 234 bvFTD, and 137 PPA patients.ResultsThere were 76.5% of bvFTD and 99.3% of PPA patients with abnormal ratings (>0) on the LANG domain; 90.2% of bvFTD and 63.5% of PPA had abnormal ratings on the BEHAV domain. In patients with a CDRstd sum of boxes score of <4, 53.7% of bvFTD had BEHAV domain and 78.6% of PPA patients had LANG domain scores >1. Among probable AD patients, 3.7% had LANG ratings that were ≥1 and 3.8% had BEHAV ratings that were ≥1. Logistic regression analyses showed that adding either the LANG or BEHAV domains to the CDRstd sum of boxes score significantly improved the discrimination between probable AD, bvFTD, and PPA.ConclusionsThe new LANG and BEHAV domains add value to the CDRstd for the characterization of the nonamnestic symptoms that are prominent in patients with bvFTD and PPA but that also occur in those with probable AD.

The demand for rapidly administered, sensitive, and reliable cognitive assessments that are specifically designed for identifying individuals in the earliest stages of cognitive decline (and to measure subtle change over time) has escalated as the emphasis in Alzheimer's disease clinical research has shifted from clinical diagnosis and treatment toward the goal of developing presymptomatic neuroprotective therapies. To meet these changing clinical requirements, cognitive measures or tailored batteries of tests must be validated and determined to be fit‐for‐use for the discrimination between cognitively healthy individuals and persons who are experiencing very subtle cognitive changes that likely signal the emergence of early mild cognitive impairment. We sought to collect and review data systematically from a wide variety of (mostly computer‐administered) cognitive measures, all of which are currently marketed or distributed with the claims that these instruments are sensitive and reliable for the early identification of disease or, if untested for this purpose, are promising tools based on other variables. The survey responses for 16 measures/batteries are presented in brief in this review; full survey responses and summary tables are archived and publicly available on the Campaign to Prevent Alzheimer's Disease by 2020 Web site (http://pad2020.org). A decision tree diagram highlighting critical decision points for selecting measures to meet varying clinical trials requirements has also been provided. Ultimately, the survey questionnaire, framework, and decision guidelines provided in this review should remain as useful aids for the evaluation of any new or updated sets of instruments in the years to come.