Activity in the peri-infarct rim in relation to recovery from stroke.
OBJECTIVE
In the rim of tissue surrounding a cortical infarct, animal studies have described an increase in a number of growth-related processes that likely contribute to behavioral recovery. The current study hypothesized that in patients with good outcome after stroke, brain activation in peri-infarct tissue would be greater than normal.


METHODS
In 15 patients with good recovery chronically after ischemic cortical stroke, activation within peri-infarct brain tissue was directly compared with activation within the same brain tissue of 13 control subjects.


RESULTS
Although most patients did show activation within peri-infarct tissues, their activation compared with controls was reduced rather than increased. Evaluation of the T2*-weighted images underlying functional MRI mapping disclosed a significant gradient of increased T2* signal in peri-infarct tissues, likely attributable to tissue changes such as gliosis.


CONCLUSIONS
Among well-recovered stroke patients, cortical activation is present in the area surrounding a cortical infarct but is smaller than normal. A baseline derangement of the T2*-weighted signal underlying functional MRI (fMRI) is also present in this area, which might influence interpretation of fMRI findings. The relationship between increased tissue T2* signal and fMRI activation is not known and requires further study.
Cramer
Steven C
SC
Department of Neurology, University of Washington, Seattle, USA. scramer@uci.edu
Shah
Rajendra
R
Juranek
Jenifer
J
Crafton
Kit R
KR
Le
Vu
V
D000368:Aged; D001921:Brain / Q000473:pathology; D002545:Brain Ischemia / Q000473:pathology; D002544:Cerebral Infarction / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology; D009474:Neurons / Q000378:metabolism; D020521:Stroke / Q000473:pathology* / Q000628:therapy*