Presenting neuropsychological testing profile of autopsy-confirmed frontotemporal lobar degeneration

Longitudinal decline in semantic versus letter fluency, but not their ratio, marks incident Alzheimer's disease in Latinx Spanish-speaking older individuals

OBJECTIVE

To compare longitudinal verbal fluency performance among Latinx Spanish speakers who develop Alzheimer's disease to those who do not develop dementia in absolute number of words produced on each task and their ratio to combine both scores.

METHOD

Participants included 833 Latinx Spanish-speaking older adults from a community-based prospective cohort in Manhattan. We performed growth curve modeling to investigate the trajectories of letter and semantic fluency, and their ratio (i.e., 'semantic index'), between individuals who developed Alzheimer's disease and those who did not (i.e., controls). The semantic index quantifies the proportion of words generated for semantic fluency in relation to the total verbal fluency performance.

RESULTS

Letter fluency performance did not decline in controls; we observed a linear decline in those who developed Alzheimer's disease. Semantic fluency declined in both groups and showed an increased rate of change over time in the incident Alzheimer's disease group; in comparison, the control group had a linear and slower decline. There were no group differences in the longitudinal trajectory (intercept and slope) of the semantic index.

CONCLUSION

A decline in letter fluency and a more rapid and accelerating decline over time in semantic fluency distinguished people who developed Alzheimer's disease from controls. Using the semantic index was not a superior marker of incident Alzheimer's disease compared to examining the two fluency scores individually. Results suggest the differential decline in verbal fluency tasks, when evaluated appropriately, may be useful for early identification of Alzheimer's disease in Latinx Spanish speakers, a historically understudied population.

Neuropsychological Profile in the C9ORF72 Associated Behavioral Variant Frontotemporal Dementia

While the C9ORF72 expansion is a major cause of behavioral variant frontotemporal dementia (bvFTD), little is known of the resultant cognitive profile. Our aim was to characterize the neuropsychological profile of the C9ORF72 associated bvFTD. We contrasted structured neuropsychological assessments of the C9ORF72 expansion carrier bvFTD patients (n = 26) with non-carrier bvFTD patients (n = 47) and those with Alzheimer's disease (AD) (n = 47). As compared to the non-carrier bvFTD patients, the C9ORF72 expansion carriers performed at a higher level in an immediate verbal memory test while showing poorer phonemic verbal fluency. Additionally, the expansion carriers committed more errors in the Stroop test and the Alternating S task relative to the non-carriers. Finally, while the AD patients outperformed both bvFTD patient groups in working memory, their performance was more impaired in episodic memory tasks relative to the bvFTD groups. We conclude that bvFTD patients carrying the C9ORF72 expansion may display more pronounced executive deficits together with less severe verbal memory impairment as compared to their non-carrier bvFTD counterparts. Knowledge of the specific neuropsychological features associated with the C9ORF72 related bvFTD may aid in the early diagnosis of the disease as well as in targeting genetic testing.

The CERAD Neuropsychological Battery in Patients with Frontotemporal Lobar Degeneration

Background/Aims

The diagnosis of frontotemporal lobar degeneration (FTLD) is based on neuropsychological examination in addition to clinical symptoms and brain imaging. There is no simple, validated, cognitive tool available in screening for FTLD. The Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery (CERAD-NB) was originally devised to identify the early cognitive changes related to Alzheimer's disease (AD). Our aim was to investigate the utility of the CERAD-NB in FTLD.

Methods

Patients with FTLD (n = 95) and AD (n = 90) were assessed with the CERAD-NB, Trail Making Test parts A and B and single-letter Phonemic Fluency.

Results

FTLD patients were more severely impaired in the Verbal Fluency subtest in the CERAD-NB and Trail Making Test part A compared to AD patients. In addition, AD patients were more impaired in memory subtests compared to FTLD patients.

Conclusion

The CERAD-NB may be a useful tool in screening for FTLD. Impaired performance in Verbal Fluency with moderately well-preserved Delayed Recall and Memory Tests may help in identifying patients with probable FTLD and discriminating FTLD from AD. Adding the Trail Making Test to the battery might enhance its value as a screening instrument for FTLD.