Right Temporal Lobe Variant of Frontotemporal Dementia: Systematic Review

Frontotemporal dementia corresponds to a heterogenous group of syndromes characterized by progressive changes in behavior and/or language. Approximately 30% of patients with primary progressive aphasia, semantic variant (semantic dementia), present with atrophy in the right cerebral hemisphere, in a rare clinical condition called right temporal variant of frontotemporal dementia (rtvFTD). The objective of the study is to present the main demographic, clinical, neuropsychological, neuroimaging, and pathologic characteristics of rtvFTD patients. A systematic review of the literature was carried out in the PubMed, LILACS, and SCIELO databases between January and March 2022. After the evaluation process, 41 articles were selected, published between 1993 and 2021. We found that rtvFTD presents with severe and progressive prosopagnosia (related to anterior temporal lobe injury) associated with behavioral symptoms-desinibition (51%), apathy (39%), obsessive-compulsive symptoms (37%), changes in eating habits (33%), and depression (28%), which is different from semantic dementia. The most common pathologic pattern is TDP-43, type C. This field of knowledge has few studies (mainly reports and case series) and heterogenous nomenclature, which is a limitation. A multinational longitudinal registry of people with rtvFTD, with standardized assessment and description of symptoms, is necessary to elucidate the characteristics of this entity.