Subcortical lesions after transient thread occlusion in the rat: T2-weighted magnetic resonance imaging findings without corresponding sensorimotor deficits.
OBJECTIVE
To investigate infarct evolution and functional consequences of exclusive subcortical or cortico-subcortical strokes, transient middle cerebral artery occlusion (MCAO) was conducted in Wistar rats.


METHODS
MCAO was induced in male Wistar rats (260-300 g) for 60 minutes. Lesion volumes and absolute T2 times on magnetic resonance imaging (MRI) were assessed 1 and 14 days after MCAO using a 4.7-T MRI animal scanner in conjunction with functional testing (adhesive tape removal, cylinder test, and ledged beam walking).


RESULTS
Functional test scores were not distinguishable between sham-operated animals (N = 5) and those with exclusive caudoputaminal infarct (N = 8; group cp), but showed significant deficits in animals with cortico-subcortical infarction (N = 10; group cp+). The cp group had lower absolute T2 times and a more pronounced reduction in T2 lesion volume over time than the subcortical component in the cp+ group. There was no correlation of T2 lesion size or absolute T2 times and functional impairment in either group.


CONCLUSIONS
When judged from functional tests alone, subcortical ischemic lesions may not be diagnosed reliably. Furthermore, T2-weighted (T2-w) MRI does not well anticipate functional deficits in primarily striatal lesions.
Wegener
Susanne
S
Max-Planck-Institute for Neurological Research, Cologne, Germany. wegener@mpin-koeln.mpg.de
Weber
Ralph
R
Ramos-Cabrer
Pedro
P
Uhlenkueken
Ulla
U
Wiedermann
Dirk
D
Kandal
Korinna
K
Villringer
Arno
A
Hoehn
Mathias
M
D000818:Animals; D004195:Disease Models, Animal; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis* / Q000503:physiopathology; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017208:Rats, Wistar