Language and behavior domains enhance the value of the clinical dementia rating scale

Abstract

Background: The 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).

Objective: To 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.

Methods: Two 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.

Results: There 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.

Conclusions: The 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.

Figure. The BEHAV and LANG domains of the augmented CDR and their descriptions in the Manual. From Uniform Data Set, NACC

Behavior, Comportment and Personality Domain: This item should be completed by a clinician or other trained health professional who is skilled in the assessment of FTLD, based on informant report and a review of the subject's cognitive functional and behavioral status. This domain is intended to assess changes in personality, aberrant behaviors and changes in interpersonal relationships from a prior customary level. The kinds of specific issues that might fall under these rubrics include: loss of insight, disinhibition, apathy, social withdrawal and disengagement, emotional lability, easy distractability, reduced empathy for the feelings of others, impulsivity and changes in eating habits and table manners. A key element of each of these is the degree to which these behaviors affect interpersonal relationships. Language Domain: This item should be completed by a clinician well versed in aphasia and aphasic disorders, based on information derived from the informant and also from clinical assessment of the patient's language functions in the course of the clinical interview and the mental status examination. This domain is intended to assess changes in language from a prior level of skill. The components of language that are primarily of interest include: spontaneous speech, auditory comprehension, object naming, reading and writing. Semantic, grammatical, and phonemic components should be reviewed. Using these in combination, the goal is to assess the subject's ability to generate and comprehend various forms of communication. The rate of speech output, also known as “fluency”, is also taken into account.