KUSAKA Yasuko Tohoku University Hospital, Research Associate, 医学部附属病院, 助手 (00292219)
SAITO Tsutomu Tohoku University, Institute of Fluid Science, Associate Professor, 流体科学研究所, 助教授 (00302224)
TAKAYAMA Kazuyoshi Tohoku University, Institute of Fluid Science, Professor, 流体科学研究所, 教授 (40006193)
|Budget Amount *help
¥12,700,000 (Direct Cost: ¥12,700,000)
Fiscal Year 2002: ¥5,600,000 (Direct Cost: ¥5,600,000)
Fiscal Year 2001: ¥7,100,000 (Direct Cost: ¥7,100,000)
Although various mechanism for traumatic brain injuries (TBI) have been proposed, much of them still hypothesis due to difficulties in elucidating their dynamic process. Therefore, we have investigated the mechanism of traumatic injury, especially the effect of shapes aid structure of skull, using the methodology of investigating shock waves, which is also a phenomena considered to be involved in the occurrence of TBI and accompanying much energy in very short period of time. The effect of shock wave on brain was also investigated in animal experiments.
Traumatic impact generated by bullet at 20 m/s was exposed on a cranium model made of acryl cylinder, 10% gelatin, teflon, water, which are mimicking skull, brain, dura, and CSF respectively, and the phenomenon within 1 ms after the impact was visualized by high-speed photography and holography. After the impact, two kinds of waves were observed (one starting from the margin toward center, and one starting at the impact point and propaga
ting parallel toward the direction of impact). Although there needs modification in experimental set up to visualize covitation and morphological lens effect of the skull which might be involved for the occurrence of coup and contra-coup injury, we could observe the tendency for the second wave to generate injury.
For the investigation of shock wave-induced brain injury, we have produced compact type shock wave generator to expose limited area of brain on shock waves (under request for patent). Using it, pressure dependent TBI were investigated histologically. The pressure threshold for the brain damage was 1 MPa. Interestingly, when shock waves were exposed on brain via skull, the animal exhibited transient paresis, but showed no evidence of histological evaluation. Therefore, we have considered this as new concussion model. Using present shock wave source and by comparing the histology and electrophysiological findings of the animal model, the role of shock waves during TBI can be clarified in the future. Less