Cerebral blood flow threshold of ischemic penumbra and infarct core in acute ischemic stroke: a systematic review.
OBJECTIVE
Cerebral blood flow (CBF) reduction below critical thresholds discriminates between irreversible infarct core, penumbra, and benign oligemia (penumbra that recovers spontaneously). Thresholds are based on animal studies, and their diagnostic accuracy in humans has never been established. The purpose of this study was to assess the evidence available on CBF thresholds for infarct core and penumbra in adult stroke patients.


METHODS
Electronic database searching using Medline, Embase and the Cochrane Library, crosschecking of references, and contact with experts and authors of primary studies was used. Studies on adult stroke patients were included if they compared CBF measurements with a diagnostic gold standard (follow-up brain CT/MRI), and reported CBF thresholds. Two reviewers independently extracted the data and assessed study quality.


RESULTS
A meta-analysis could not be carried out because of insufficient data. The optimal reported CBF thresholds varied widely, from 14.1 to 35.0 and from 4.8 to 8.4 mL/100 g per minute for penumbra and infarct core, respectively.


CONCLUSIONS
The use of CBF thresholds in commercial software for imaging methods cannot be recommended without further evaluation.
Institute of Anesthesiology-Intensive Care, University of Brescia, Italy.
Elisabetta
E
Bandera
Marco
M
Botteri
Cosetta
C
Minelli
Alex
A
Sutton
Keith R
KR
Abrams
Nicola
N
Latronico
D000328:Adult; D002560:Cerebrovascular Circulation; D016206:Databases, Bibliographic; D018450:Disease Progression; D006801:Humans; D020521:Stroke / Q000473:pathology / Q000503:physiopathology