Contributions of Neuroimaging to Understanding Language Deficits in Acute Stroke.
Rajani Sebastian, Bonnie L Breining
PMID 29359306WHAT IT FOUND
Diffusion and perfusion MRI in acute stroke can show language-area dysfunction even before visible infarct, and fMRI shows activation shifting during recovery.
These findings help explain deficits and prognosis. They do not yet guide speech therapy.
Key findings
01Perfusion MRI abnormalities in Wernicke's area correlated with word comprehension errors even without visible infarct, and perfusion measures were more closely related to cognitive performance than diffusion measures.
02In a small longitudinal fMRI study of 14 people with aphasia, language recovery was associated with activation shifting from right to left hemisphere.
03Resting-state connectivity between language regions improved only in participants who recovered naming, and connectivity appeared more important than activation alone.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
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What it does not show
This is a narrative review, not a systematic review, so the studies it cites were selected by the authors and may not represent all evidence. Most imaging findings come from small studies, and many DTI and fMRI studies focus on chronic stroke rather than acute care. DWI and PWI mismatch is not universal; some patients have similar DWI and PWI abnormalities or DWI lesion reversal, so scans do not always predict salvageable tissue or recovery. fMRI in stroke is limited by neurovascular coupling changes, head motion, scanner noise, and the need to choose tasks that patients can perform. The review does not report a new patient sample, randomisation, blinding, or a pre-registered primary outcome.
Declared interests
The supplied text does not include an author conflict statement; the publication types list NIH extramural research support.
The easy way to misread this
Do not read these imaging findings as proof that scans should direct aphasia therapy. The review is about mechanisms and small studies, and it says DTI has not made much impact on treatment and diagnosis during the acute phase.