Inverse mismatch and lesion growth in small subcortical ischaemic stroke.
OBJECTIVE
Infarction typically develops within the borders of an initial hypoperfused tissue. We prospectively investigated whether in small subcortical stroke patients infarct growth can occur beyond the margins of the affected vascular territories.


METHODS
In 19 consecutive patients, stroke MRI was performed within 14 h after ictus, and at days 2 and 6 (± 1). Size of diffusion and perfusion disturbances were determined. Infarct volume measured on T2-weighted images on day 6 was considered as imaging endpoint.


RESULTS
At the initial examination, the mean diffusion lesion [apparent diffusion coefficient (ADC) lesion size, 1.82 ± 1.2 ml] was larger (p = 0.0002) than the perfusion lesion [mean transit time (MTT) lesion size, 0.72 ± 0.69 ml]. Such an "inverse mismatch" (ADC lesion > MTT lesion) was present in 14/19 patients at baseline and in all patients on day 2. Final lesion volume at day 6 was 3.2 ± 1.6 ml which was larger than the initial perfusion deficit (p = 0.02).


CONCLUSIONS
In small subcortical ischaemic stroke "inverse mismatch" is frequent and infarction develops beyond the initial perfusion disturbance. This indicates that cytotoxic processes probably triggered by the infarct core are a dominant mechanism for lesion growth. Areas with normal perfusion but which are threatened by cytotoxic damage developing over several days seem prime targets for neuroprotective therapy.
Fiebach
Jochen B
JB
Department of Neurology, Center for Stroke Research Berlin & Berlin NeuroImaging Center, Charité Universitätsmedizin Berlin, Berlin, Germany. jochen.fiebach@charite.de
Hopt
Alexander
A
Vucic
Tomislav
T
Brunecker
Peter
P
Nolte
Christian H
CH
Doege
Claudia
C
Villringer
Kersten
K
Jungehulsing
Gerhard J
GJ
Kunze
Claudia
C
Wegener
Susanne
S
Villringer
Arno
A
D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000473:pathology*