Stroke location and brain function in an embolic rabbit stroke model.
OBJECTIVE
Current rabbit stroke models often depend on symptoms as endpoints for embolization and produce wide variation in location, size, and severity of strokes. In a further refinement of an angiographic embolic stroke model, localized infarctions were correlated to neurologic deficits with the goal to create a rabbit model for long-term studies of therapies after stroke.


METHODS
New Zealand White rabbits (4-5 kg; N = 71) had selective internal carotid artery (ICA) angiography and a single clot was injected. At 24 hours, neurologic assessment score (NAS) was measured on an 11-point scale (0, normal; 10, dead). Brains were removed and stained to identify stroke areas. All animals with single strokes (n = 31) were analyzed by specific brain structure involvement, and NAS values were correlated.


RESULTS
Stroke incidence differed by location, with cortex, subcortical, and basal ganglia regions highest. The middle cerebral artery (MCA), at 52%, and anterior cerebral artery (ACA), at 29%, were most commonly involved, with the largest stroke volumes in the ACA distribution. Brainstem and cerebellum strokes had disproportionately severe neurologic deficits, scoring 2.25 +/- 1.0 on the NAS, which represented a significant (P < .02) difference versus cortex (0.5 +/- 0.2), subcortical (1.3 +/- 0.4), and basal ganglia (0.5 +/- 0.3), all in the frontal or parietal regions.


CONCLUSIONS
MCA and ACA distributions included 81% of strokes. These sites were relatively silent (potentially allowing longer-term survival studies) whereas others in the posterior circulation produced disproportionately severe symptoms. Symptoms were not reliable indicators of stroke occurrence, and other endpoints such as imaging may be required. These are important steps toward refinement of the rabbit stroke model.
Brown
Aliza T
AT
Department of Radiology, University of Arkansas for Medical Sciences, M1/269, 4301 West Markham Street, Mail Slot 556, Little Rock, AR 72205, USA.
Skinner
Robert D
RD
Flores
Rene
R
Hennings
Leah
L
Borrelli
Michael J
MJ
Lowery
John
J
Culp
William C
WC
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004195:Disease Models, Animal; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*; D011817:Rabbits; D011859:Radiography; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology*