Evaluating the Role of Pendrin in Zebrafish Inner Ear Development

4:45PM Claire Cordella Language-based strategies for subtyping of patients with primary progressive aphasia PI: Brad Dickerson, Massachusetts General Hospital A subset of the Cambridge Semantic Battery (CSB) testing category comprehension was administered to thirty-six subjects with a diagnosis of primary progressive aphasia (PPA). Subjects’ diagnoses were of three subtypes: agrammatic PPA, logopenic PPA and semantic PPA. The goal of the research was to determine the effectiveness of the CSB subtest in identifying language deficits in the subject group as a whole and differentiating between subjects with different subtype diagnoses (i.e. agrammatic v. logopenic v. semantic). Preliminary statistical analyses revealed significantly lower scores on the CSB for subjects with semantic PPA, as compared to those with either agrammatic or logopenic PPA. Logopenics scored lower than did agrammatics, but differences between these two subgroups were not significant. Data was further broken down based on the animacy condition of the target item (i.e. animate v. inanimate), and similar patterns of significance emerged, showing impaired performance among semantic PPA subjects. The relative gap between animateand inanimate-type scores was also greatest for semantic subtype patients, who had comparatively more difficulty in the animacy condition. These results are interpreted in light of current clinical thought, which assigns impairments related to object recognition and/or naming as diagnostic hallmarks of semantic PPA. The results reinforce the general utility of the CSB in revealing deficits in semantic category comprehension associated with semantic PPA, but demonstrate also its failure to reliably differentiate between the logopenic and agrammatic variants of PPA. Results thus reinforce the clinical necessity of a comprehensive battery of diagnostic language tasks which, taken together, may help to enable the subtyping of PPA subjects. Toward that end, an existing subtyping schema which relies on both language testing and subjective clinician ratings is tested and briefly discussed, with promising results.