Abstract Details

Title Multimodal Imaging and Perceptual Features in Two Patient with Anterior Versus Posterior Primary Progressive Prosopagnosia

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P11 - Poster Session 11 (11:45 AM-12:45 PM)

Poster/Presentation
Number 3-005

Background Prosopagnosia is common with right temporal lesions, often in the fusiform gyrus when caused by vascular pathology. When caused by frontotemporal dementia, the lesion typically begins in the temporal tip. We contrasted neuropsychological findings and multimodal imaging in two patients with the right temporal variant of frontotemporal dementia (RTVFTD), one starting at the temporal tip and another at the posterior extent of the fusiform gyrus.

Objective To report the neuroimaging features and neuropsychological presentation of two patients with primary progressive prosopagnosia with different anatomical involvement along the right temporal lobe.

Design/Methods Two RTVFTD amyloid-negative patients underwent MRI and PET using ¹¹C-PBR28, an inflammation tracer, and ¹⁸F-flortaucipir. V_T values for ¹¹C-PBR28 were calculated with the Logan plot and a metabolite-corrected arterial input function. For ¹⁸F-flortaucipir, the SUV ratio over the cerebellar gray matter was calculated for t = 80-100 min. Patients had a detailed neuropsychological assessment, including an extensive facial and object recognition battery.

Results Atrophy, ¹¹C-PBR28 uptake and ¹⁸F-flortaucipir uptake involved a similar region, but differently localized in each patient, the pole in one and the fusiform gyrus in the other. Both patients had prosopagnosia and difficulty with naming tasks. However, the patient with the anterior lesion showed associative prosopagnosia, with mostly intact perceptual abilities, but impaired performance on naming and associative tasks, while the patient with the posterior lesion showed the opposite pattern, suggestive of a severe apperceptive prosopagnosia.

Conclusions Although prosopagnosia from ischemic and other lesions in the right posterior temporo-occipital region is common, primary progressive prosopagnosia in the absence of amyloid has been described mostly with involvement of the right anterior temporal region. As exemplified by our second patient, it can also happen with posterior temporal involvement and in this case the prosopagnosia, of an apperceptive nature, can be even more severe than when the temporal tip is affected.

Authors/Disclosures
Kathleen Bradbury (Houston Methodist Hospital) PRESENTER	Ms. Bradbury has nothing to disclose.
	No disclosure on file
Johanna Appleton (Houston Methodist)	No disclosure on file
Quentin Funk	No disclosure on file
	No disclosure on file
Joseph C. Masdeu, MD, PhD, FAAN (Houston Methodist Neurological Institute)	Dr. Masdeu has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Biogen. The institution of Dr. Masdeu has received research support from NIH. The institution of Dr. Masdeu has received research support from Moody Foundation. The institution of Dr. Masdeu has received research support from Biogen. The institution of Dr. Masdeu has received research support from Eli Lilly. The institution of Dr. Masdeu has received research support from Eisai. The institution of Dr. Masdeu has received research support from Novartis. Dr. Masdeu has received publishing royalties from a publication relating to health care. Dr. Masdeu has received personal compensation in the range of $100,000-$499,999 for serving as a Director, Nantz Nal Alzheimer Center with HOUSTON METHODIST NEUROLOGICAL INSTITUTE.
Belen Pascual, PhD (Houston Methodist Hospital)	The institution of Prof. Pascual has received research support from NIH. The institution of Prof. Pascual has received research support from NIH.