What is a core symptom of the language disturbance in Semantic dementia

• Published in: Higher Brain Function Research Vol. 35; no. 3; pp. 304 - 311
• Main Authors: Ikeda, Manabu, Ichimi, Naoko, Hashimoto, Mamoru
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Society for Higher Brain Function 30.09.2016
• Subjects: semantic dementia, Gogi aphasia, verbal semantic memory disturbance, idiom, metaphor
• ISSN: 1348-4818; 1880-6554
• DOI: 10.2496/hbfr.35.304

In the present study, we investigated the clinical characteristics of verbal semantic memory impairment in Semantic dementia through the comprehension of idiomatic phrase. The subjects were seven SD patients with mild to moderate word meaning (Gogi) aphasia. All subjects showed a severe difficulty in understanding the meaning of idiomatic phrases. Because idiom has a meaning in itself and consists of nothing but language, idiom could be considered as a kind of verbal semantic memory. Therefore, the present result suggested that SD had profound deficit of verbal semantic memory even in the early stage. Secondly, a patient with SD was evaluated his ability to comprehend two types of word meaning, one is the concrete meaning and the other is the figurative meaning which has been derived from the concrete meaning. The patient could comprehend the concrete word meanings but could not comprehend words used as a metaphor at all. Thus we suppose the deteriorated process of language in SD as follows: first, deficits of word meaning as a metaphor, second the loss of concrete word meaning, and development to Gogi aphasia.