Automatic MRI Quantifying Methods in Behavioral-Variant Frontotemporal Dementia Diagnosis.

AIMS: We assessed the value of automated MRI quantification methods in the differential diagnosis of behavioral-variant frontotemporal dementia (bvFTD) from Alzheimer disease (AD), Lewy body dementia (LBD), and subjective memory complaints (SMC). We also examined the role of the C9ORF72-related genetic status in the differentiation sensitivity. METHODS: The MRI scans of 50 patients with bvFTD (17 C9ORF72 expansion carriers) were analyzed using 6 quantification methods as follows: voxel-based morphometry (VBM), tensor-based morphometry, volumetry (VOL), manifold learning, grading, and white-matter hyperintensities. Each patient was then individually compared to an independent reference group in order to attain diagnostic suggestions. RESULTS: Only VBM and VOL showed utility in correctly identifying bvFTD from our set of data. The overall classification sensitivity of bvFTD with VOL + VBM achieved a total sensitivity of 60%. Using VOL + VBM, 32% were misclassified as having LBD. There was a trend of higher values for classification sensitivity of the C9ORF72 expansion carriers than noncarriers. CONCLUSION: VOL, VBM, and their combination are effective in differential diagnostics between bvFTD and AD or SMC. However, MRI atrophy profiles for bvFTD and LBD are too similar for a reliable differentiation with the quantification methods tested in this study.

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.