%0 Journal Article %J J Alzheimers Dis %D 2018 %T Patterns of Neuropsychological Dysfunction and Cortical Volume Changes in Logopenic Aphasia. %A Owens, Tyler E %A Machulda, Mary M %A Duffy, Joseph R %A Strand, Edythe A %A Clark, Heather M %A Boland, Sarah %A Martin, Peter R %A Lowe, Val J %A Jack, Clifford R %A Whitwell, Jennifer L %A Josephs, Keith A %X

BACKGROUND: Neuropsychological assessment can add essential information to the characterization of individuals presenting with the logopenic variant of primary progressive aphasia (lvPPA).

OBJECTIVE: This study examined the neuropsychological characteristics of lvPPA patients. We also examined differences in regional and whole brain atrophy based on neuropsychological profiles.

METHODS: We conducted a hierarchical cluster analysis on memory, executive functioning, and visuospatial neuropsychological test data for 56 individuals with lvPPA. We then compared resultant clusters to left middle temporal, inferior parietal, and superior parietal regions-of-interest using multivariate analysis of covariance. We also performed voxel-level analyses.

RESULTS: We identified three clusters characterized as lvPPA with no neurocognitive impairment (n = 5), lvPPA with mild neurocognitive deficits (n = 23), and lvPPA with marked cognitive deficits (n = 28). WAB-AQ was associated with left middle temporal volume. Superior parietal volumes were smaller for the lvPPA group with marked cognitive symptoms compared to the less severe groups. Voxel-level analyses showed greater atrophy in temporal, parietal, lateral occipital, and frontal regions, left worse than right. Age, disease duration, gender, WAB-AQ, and PiB-PET did not account for differences between groups.

CONCLUSIONS: LvPPA patients without cognitive deficits in other domains were relatively uncommon while 50% of our sample exhibited pronounced neurocognitive deficits outside the language domain. Pronounced cognitive deficits in lvPPA are associated with widespread atrophy, left worse than right. Our study underscores the importance of examining neuropsychological function in addition to language in patients with lvPPA.

%B J Alzheimers Dis %V 66 %P 1015-1025 %8 2018 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/30372673?dopt=Abstract %R 10.3233/JAD-171175 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Regional Distribution, Asymmetry, and Clinical Correlates of Tau Uptake on [18F]AV-1451 PET in Atypical Alzheimer's Disease. %A Tetzloff, Katerina A %A Graff-Radford, Jonathan %A Martin, Peter R %A Tosakulwong, Nirubol %A Machulda, Mary M %A Duffy, Joseph R %A Clark, Heather M %A Senjem, Matthew L %A Schwarz, Christopher G %A Spychalla, Anthony J %A Drubach, Daniel A %A Jack, Clifford R %A Lowe, Val J %A Josephs, Keith A %A Whitwell, Jennifer L %X

BACKGROUND: Despite common pathology, Alzheimer's disease (AD) can have multiple clinical presentations which pathological studies suggest result from differences in the regional distribution of tau pathology. Positron emission tomography (PET) ligands are now available that can detect tau proteins in vivo and hence can be used to investigate the biological mechanisms underlying atypical AD.

OBJECTIVE: To assess regional patterns of tau uptake on PET imaging in two atypical AD variants, posterior cortical atrophy (PCA) and logopenic progressive aphasia (lvPPA).

METHODS: Eighteen PCA and 19 lvPPA subjects that showed amyloid-β deposition on PET underwent tau-PET imaging with [18F]AV-1451. Group comparisons of tau uptake in PCA and lvPPA were performed using voxel-level and regional-level analyses. We also assessed the degree of lobar tau asymmetry and correlated regional tau uptake to age and performance on clinical evaluations.

RESULTS: Both syndromes showed diffuse tau uptake throughout all cortical regions, although PCA showed greater uptake in occipital regions compared to lvPPA, and lvPPA showed greater uptake in left frontal and temporal regions compared to PCA. While lvPPA showed predominant left-asymmetric tau deposition, PCA was more bilateral. Younger subjects showed greater tau uptake bilaterally in frontal and parietal lobes than older subjects, and sentence repetition, Boston naming test, simultanagnosia, and visuoperceptual function showed specific regional tau correlates.

CONCLUSION: Tau deposition is closely related to clinical presentation in atypical AD with age playing a role in determining the degree of cortical tau deposition.

%B J Alzheimers Dis %V 62 %P 1713-1724 %8 2018 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/29614676?dopt=Abstract %R 10.3233/JAD-170740