Funktionelle Reorganisation bei Aphasie

Zusammenfassung

Inzwischen liegen einige Studien mit bildgebenden Verfahren zur funktionellen Reorganisation bei Aphasie vor. Diese untersuchen jedoch immer normale sprachliche Funktionen bei Aphasikern, z. B. den Zugriff auf Wortbedeutungen, und nicht aphasische Symptome wie z. B. Paraphasien oder Sprachautomatismen.

Während einige Autoren beobachten, dass geschädigte linkshemisphärische Areale durch homologe Areale der rechten Hemisphäre funktionell unterstützt bzw. ersetzt werden, betonen andere Autoren die Bedeutung der erhaltenen Areale der linken Hemisphäre für einen guten Rückbildungsverlauf. Neuere Studien postulieren einen Rückbildungsverlauf, währenddessen zunächst schwache Aktivierungen in linkshemisphärischen Arealen zu beobachten sind, die im Verlauf zunehmen und sich auf die rechte Hemisphäre ausdehnen und später im Zuge einer Konsolidierung der sprachlichen Leistungen wieder vorwiegend in der linken Hemisphäre zu beobachten sind.

Abstract

Several neuroimaging studies focus on functional reorganisation in aphasia. In these studies aphasic patients were always presented with normal language tasks, e. g. access to lexical meaning. Aphasic symptoms like paraphasias or automatisms, however, have not yet been studied.

While some authors observed activation in the right hemisphere in regions homologue to those which were damaged, others underline the importance of left hemisphere perilesional areas for a good outcome. Recent studies assume different phases of recovery: initially few activations in the left hemisphere, followed by an overall increase including the right hemisphere and finally a decrease and a re-shift to the left hemisphere in connection with consolidation of language abilities.

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