Language Networks Imaging in Primary Progressive Aphasia in a Latin Population

CALANDRI I, AMENGUAL A, CHAVES H, ROLLAN C, FAREZ M, SABE L, MEDINA C, ZANUSO P, CAMPOS J, COHEN J, CALVAR J SEVLEVER G, ALLEGRI R.

Congreso; Annual Meeting of the American Academy of Neurology; 2014

American Academy of Neurology

OBJECTIVE:To evaluate DTI-based tractography potential value in the diagnosis of variants of PPA and confirm the reliability of previous findings in other populationsBACKGROUND:Primary progressive aphasia (PPA) is a disorder of declining language due to a neurodegeneration disease. Three main variants have been described: Non-fluent/Agrammatic (NV), Semantic (SV) and Logopenic (LV). Each one is related to the involvement of specific components of the language network, conferring them differential clinical features and patterns of brain atrophy. Few previous studies, conducted in an American population, have used DTI techniques to quantify the commitment of the white matter and connectivity in this entityDESIGN/METHODS:A case-control study where 17 subjects with PPA (NV n=6, LV n=4 and SV n=7) were identified and matched by age and gender to 6 controls. We used DTI-based tractography to evaluate inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and uncinate fasciculus (UF) bilaterally, and compared fractional anisotropy (FA) and mean difussivity (MD)RESULTS:Compare with controls, SV patients had significantly lower FA of Left ILF compared (p<0.006) and significantly higher MD in rigth (p<0.007) and left UF (p<0.002), we found significant differences in left ILF (p<0.001) also.In NV we found significantly lower FA in comparison with controls for the left UF (p<0.013)CONCLUSIONS:Our results show that, in the patients we analyzed, SV group had greater white matter alterations. This finding is consistent with the results reported in the literature. Remarkably, this study was conducted in an emerging economy with free public access image processing tools. Its growing accessibility makes tractography a tool that moves away from the research field to become, in the future, a useful clinical tool in the study of patients with dementia