[Aphasia in practice--recent progress].

In terms of practical view, the type of aphasia can be classified by four elementary symptoms: anarthria (apraxia of speech), phonemic paraphasia, word comprehension impairment, word finding difficulty. Each elementary symptom has been established by causative lesion: anarthria for lowed posterior part of the left precentral gyrus, phonemic paraphasia for the left marginal gyrus and underlying white matter, word comprehension impairment for the left middle frontal gyrus or the posterior part of superior and middle temporal gyrus (the area called Wernickle's area), word finding difficulty for the left inferior frontal gyrus or the left angular gyrus or the left posterior part of the inferior temporal gyrus. In addition to ordinary estimation of language some devised examination enables distinction of the symptoms due to frontal lesion and the symptom due to the posterior lesion. This methods taking advantage of the symptoms related apahasia is also useful for making diagnosis and knowing prognosis of progressive aphasia.