[Language Symptoms of Alzheimer's Disease].

Alzheimer's disease (AD) is a neurodegenerative disorder mainly characterized by progressive memory disturbance. Language symptoms are considered to be less disease specific and therefore did not attract many researchers, interest until recently. Typical patients with AD present amnesic aphasia in the early disease stage followed by transcortical sensory aphasia; however, their language symptoms are varied. Recently, the concept of logopenic variant of primary progressive aphasia (PPA) has been developed, which is reported to have Alzheimer's neuropathology. Clinicians should verify patients' language abilities, as language can be the key to reveal their true cognitive functions.