Multimodal semantic battery to monitor progressive loss of concepts in the semantic variant of primary progressive aphasia (svPPA): an innovative proposal.

Semantic variant primary progressive aphasia (svPPA) is a rare neurodegenerative disease characterized by a progressive loss of semantic knowledge. Patients with svPPA show anomia, impaired word comprehension, poor object recognition, and difficulties in retrieving semantic information. svPPA is also a unique "natural" model that allows clinicians and cognitive neuroscientists to study the organization of semantic memory because only semantic knowledge is affected in the initial period of the disease, with relative sparing of other cognitive domains. In the clinical practice, semantic memory is commonly tested only with verbal tests. The aim of the present study was to preliminary test a new Multimodal Semantic Battery developed in our laboratory, which comprised 11 subtests designed to assess the semantic knowledge of multiple items via all input modalities. The battery was administered twice, over four years, to a patient diagnosed with svPPA. We found that when extensively tested with multiple tests, in some cases, he was still able to recall semantic features of the items that otherwise would not have emerged with standard semantic tests. These results are discussed for the clinical practice: monitoring semantic memory through all modalities in a practical and reliable way could be useful for both clinicians and experimental researchers to better investigate the breakdown of semantic knowledge.