Citations

AbstractIntroductionConventional Z‐scores are generated by subtracting the mean and dividing by the standard deviation. More recent methods linearly correct for age, sex, and education, so that these “adjusted” Z‐scores better represent whether an individual's cognitive performance is abnormal. Extreme negative Z‐scores for individuals relative to this normative distribution are considered indicative of cognitive deficiency.MethodsIn this article, we consider nonlinear shape constrained additive models accounting for age, sex, and education (correcting for nonlinearity). Additional shape constrained additive models account for varying standard deviation of the cognitive scores with age (correcting for heterogeneity of variance).ResultsCorrected Z‐scores based on nonlinear shape constrained additive models provide improved adjustment for age, sex, and education, as indicated by higher adjusted‐R2.DiscussionNonlinearly corrected Z‐scores with respect to age, sex, and education with age‐varying residual standard deviation allow for improved detection of non‐normative extreme cognitive scores.

AbstractIntroductionThe Advancing Research and Treatment in Frontotemporal Lobar Degeneration and Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects longitudinal studies were designed to describe the natural history of familial‐frontotemporal lobar degeneration due to autosomal dominant mutations.MethodsWe examined cognitive performance, behavioral ratings, and brain volumes from the first time point in 320 MAPT, GRN, and C9orf72 family members, including 102 non–mutation carriers, 103 asymptomatic carriers, 43 mildly/questionably symptomatic carriers, and 72 carriers with dementia.ResultsAsymptomatic carriers showed similar scores on all clinical measures compared with noncarriers but reduced frontal and temporal volumes. Those with mild/questionable impairment showed decreased verbal recall, fluency, and Trail Making Test performance and impaired mood and self‐monitoring. Dementia was associated with impairment in all measures. All MAPT carriers with dementia showed temporal atrophy, but otherwise, there was no single cognitive test or brain region that was abnormal in all subjects.DiscussionImaging changes appear to precede clinical changes in familial‐frontotemporal lobar degeneration, but specific early clinical and imaging changes vary across individuals.

AbstractIntroductionBehavior/Comportment/Personality (BEHAV) and Language (LANG) domains were added to the Clinical Dementia Rating (CDR®) for improving evaluation of patients with frontotemporal lobar degeneration (FTLD) (CDR® plus NACC FTLD).MethodsWe analyzed the CDR® plus NACC FTLD among participants from the baseline visit of the Advancing Research and Treatment for Frontotemporal Lobar Degeneration/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects Consortium.ResultsThe CDR® plus NACC FTLD was able to detect early symptoms in the mildly impaired participants who were rated as CDR® sum of boxes (CDR®‐SB) = 0. The CDR®‐SB was not sensitive, particularly in participants with mild nonfluent/agrammatic primary progressive aphasia. Participants with familial and sporadic behavioral variant FTD exhibited similar CDR® plus NACC FTLD profiles except that language impairment was more frequent in participants with mild sporadic behavioral variant FTD. Adding the BEHAV and/or LANG domains to the CDR®‐SB significantly enhanced discriminatory power in differentiating among the FTLD spectrum disorders.DiscussionThe BEHAV and LANG domains enable the CDR® plus NACC FTLD to capture early symptomatology of FTLD.