Abstract
Language and speech symptoms associated with common type of Alzheimerʼs disease (AD) are reflected by the underlying pathological process, usually presenting as anomic aphasia evolving to transcortical sensory aphasia.
There are subtypes of AD which show various language symptoms with relatively preserved other cognitive functions. Besides the logopenic progressive aphasia (LPA) that is one of three variants of primary progressive aphasia, there may be other types of aphasic AD, presenting as (1) anomia with agraphia for Kanji, (2) transcortical sensory aphasia, (3) Gogi aphasia-like symptoms which resemble semantic dementia (SD) . Type (1) or (2) is associated with predominant degeneration in the left hemisphere with similar distribution pattern observed in common type of AD. Type (3) is associated with left temporal lobe atrophy, and so possibility of misdiagnosing as SD is high. Careful xamination of language and dementia symptoms, however, would lead to the precise diagnosis of AD.
Linguistic profiles in the cases with LPA are various in terms of the severity of each symptom that constitute the diagnostic criteria of this syndrome. Therefore, LPA might not be a discrete homogeneous syndrome. Severe disturbance in verbal short-term memory, however, would be the most important symptom in the sense that degenerative aphasia develops a characteristic clinical teature of system degeneration.
