大脳皮質連合野病変の症候学

Understanding the Neuropsychological Symptoms Associated with Cortical Dysfunction

大脳皮質連合野の病変は，認知や行動に関わる神経心理学的症候をきたす。神経心理学的症候と病巣部位との関係は緩やかなもので，多くの要因により変化する。近年，対象とする疾患が脳血管障害をはじめとする局所脳損傷から神経変性疾患に広がってきたことを受けて，捉えられる症候にも変化がみられる。大脳皮質連合野の症候を整理していくためには，神経科学的知見を取り入れつつ，疾患ごとの病態を考慮した検討が必要と考えられる。

Abstract

Damage to association cortices can result in a variety of cognitive and behavioral symptoms. Superficially, the relationship between lesion sites and the corresponding symptoms seems constant. However, some degree of dissociation of symptoms among patients with different etiologies appears to be the rule rather than the exception, even when the lesion locations appear similar in neuroimaging studies. Examinations of patients with primary progressive aphasia (PPA) have challenged the classic language model that is based on observations mainly made in patients with cerebrovascular diseases. The neuropsychological findings of patients with semantic variant PPA and neuroimaging evidence in healthy subjects converge to indicate that the anterior temporal lobe is an important component of language and semantic networks. Recent findings, however, have demonstrated that atrophy and dysfunction in patients with semantic variant PPA involve a number of regions in addition to the anterior temporal lobe. This indicated that specifically linking language deficits to the anterior temporal lobe is difficult. An understanding the pathophysiological processes is require to comprehend the symptoms of cortical dysfunction, especially in the association cortices.