Right Temporal Degeneration and Conceptual Loss of Emotions: Semantic-variant Frontotemporal Dementia? (2217)

Objective: Describe the early symptoms and propose a unifying nomenclature and criteria for right-predominant temporal lobe degeneration. Background: To date, the clinical profile of right-predominant temporal lobe neurodegeneration remains elusive. We performed an in-depth analysis of 19 patients with right temporal variant and an autopsy diagnosis of frontemporal lobar degeneration (FTLD)[FTLD-TDP type-C (n=13); FTLD-TDP type-A due to progranulin mutation (n=2); Pick’s disease(n=4)]. Design/Methods: We evaluated the clinical and behavioral profile of an autopsy confirmed series of patients given any of the following diagnoses during life: Right-temporal semantic-variant primary progressive aphasia (svPPA), right-temporal behavioral-variant frontotemporal dementia (bvFTD), or right semantic dementia (SD). Voxel-based morphometry was used to assess gray matter atrophy. Results: The most common first, second and third symptoms were loss of empathy (68%, n=13/19), loss of person, object and language-related knowledge (63%, n=12/19) and compulsive behavior (42%, n=8), respectively. Neuropsychological testing revealed impairment in executive and memory domains (Trails and CVLT −3.7 and −2.9 SD below the mean (btm), respectively). Semantic and verbal fluencies were −3SD and −2SD btm, respectively). Naming on BNT was (−12SD btm), comprehension on PPVT was (−12SD btm), non-verbal semantics on Pyramid and Palm Trees-Pictures was (−22SD btm), famous faces naming and familiarity were (−3.8SD and −3.4SD btm, respectively). Affect matching on CATS was (−3.8SD btm). Visuospatial systems were spared; Benson figure copy (−1SD), VOSP (0.2SD) btm. Impaired emotional and cognitive empathy on IRI-EC and PT (−2.4SD and −2.8SD btm, respectively), decreased warmth on IAS at (−17SD btm), and difficulty understanding complex emotions and social cues on TASIT-EE, SI-M for Sincere and Sarcastic were (−0.7SD, −0.1 and −9 SD btm, respectively). Early in the disease course, patients did not fulfill the current diagnostic criteria for either bvFTD or svPPA but showed a combination of features spanning both and had loss of person-specific knowledge. Conclusions: Right temporal lobe degeneration presents with distinct early clinical and neuroimaging findings and has high clinical-pathological predictive specificity. A unified nomenclature and diagnostic criteria could help with early diagnosis. Disclosure: Dr. Younes has nothing to disclose. Dr. Montembeault has nothing to disclose. Dr. Borghesani has nothing to disclose. Dr. Welch has nothing to disclose. Dr. Spina has nothing to disclose. Dr. Grinberg has nothing to disclose. Dr. Seeley has nothing to disclose. Dr. Miller has nothing to disclose. Dr. Miller has nothing to disclose. Dr. Gorno Tempini has nothing to disclose.