Imaging short- and long-term training success in chronic aphasia.
BACKGROUND
To date, functional imaging studies of treatment-induced recovery from chronic aphasia only assessed short-term treatment effects after intensive language training. In the present study, we show with functional magnetic resonance imaging (fMRI), that different brain regions may be involved in immediate versus long-term success of intensive language training in chronic post-stroke aphasia patients.


RESULTS
Eight patients were trained daily for three hours over a period of two weeks in naming of concrete objects. Prior to, immediately after, and eight months after training, patients overtly named trained and untrained objects during event-related fMRI. On average the patients improved from zero (at baseline) to 64.4% correct naming responses immediately after training, and treatment success remained highly stable at follow-up. Regression analyses showed that the degree of short-term treatment success was predicted by increased activity (compared to the pretraining scan) bilaterally in the hippocampal formation, the right precuneus and cingulate gyrus, and bilaterally in the fusiform gyri. A different picture emerged for long-term training success, which was best predicted by activity increases in the right-sided Wernicke's homologue and to a lesser degree in perilesional temporal areas.


CONCLUSIONS
The results show for the first time that treatment-induced language recovery in the chronic stage after stroke is a dynamic process. Initially, brain regions involved in memory encoding, attention, and multimodal integration mediated treatment success. In contrast, long-term treatment success was predicted mainly by activity increases in the so-called 'classical' language regions. The results suggest that besides perilesional and homologue language-associated regions, functional integrity of domain-unspecific memory structures may be a prerequisite for successful (intensive) language interventions.
Menke
Ricarda
R
Department of Neurology, University of Münster, Münster, Germany.
Meinzer
Marcus
M
Kugel
Harald
H
Deppe
Michael
M
Baumgärtner
Annette
A
Schiffbauer
Hagen
H
Thomas
Marion
M
Kramer
Kira
K
Lohmann
Hubertus
H
Flöel
Agnes
A
Knecht
Stefan
S
Breitenstein
Caterina
C
D000328:Adult; D000368:Aged; D000849:Anomia / Q000503:physiopathology / Q000628:therapy; D001037:Aphasia / Q000503:physiopathology / Q000628:therapy*; D001931:Brain Mapping; D002908:Chronic Disease; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007808:Language Therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011597:Psychomotor Performance / Q000502:physiology; D020127:Recovery of Function; D012044:Regression Analysis; D013702:Temporal Lobe / Q000503:physiopathology*; D016896:Treatment Outcome; D014825:Vocabulary