Cerebral blood volume alterations in the perilesional areas in the rat brain after traumatic brain injury--comparison with behavioral outcome.
In the traumatic brain injury (TBI) the initial impact causes both primary injury, and launches secondary injury cascades. One consequence, and a factor that may contribute to these secondary changes and functional outcome, is altered hemodynamics. The relative cerebral blood volume (CBV) changes in rat brain after severe controlled cortical impact injury were characterized to assess their interrelations with motor function impairment. Magnetic resonance imaging (MRI) was performed 1, 2, 4 h, and 1, 2, 3, 4, 7, and 14 days after TBI to quantify CBV and water diffusion. Neuroscore test was conducted before, and 2, 7, and 14 days after the TBI. We found distinct temporal profile of CBV in the perilesional area, hippocampus, and in the primary lesion. In all regions, the first response was drop of CBV. Perifocal CBV was reduced for over 4 days thereafter gradually recovering. After the initial drop, the hippocampal CBV was increased for 2 weeks. Neuroscore demonstrated severely impaired motor functions 2 days after injury (33% decrease), which then slowly recovered in 2 weeks. This recovery parallelled the recovery of perifocal CBV. CBV MRI can detect cerebrovascular pathophysiology after TBI in the vulnerable perilesional area, which seems to potentially associate with time course of sensory-motor deficit.
Biomedical NMR Group, Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland. riikka.immonen@uku.fi
Riikka
R
Immonen
Taneli
T
Heikkinen
Leena
L
Tähtivaara
Antti
A
Nurmi
Taina-Kaisa
TK
Stenius
Jukka
J
Puoliväli
Tinka
T
Tuinstra
Amie L
AL
Phinney
Bernard
B
Van Vliet
Juha
J
Yrjänheikki
Olli
O
Gröhn
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001810:Blood Volume / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000502:physiology; D001930:Brain Injuries / Q000473:pathology / Q000503:physiopathology; D002196:Capillaries / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology; D012039:Regional Blood Flow