The Effect of Arachidonic Acid Infused into the Feline Brain White Matters on Somatosensory Evoked Potentials.
- Author:
Kwan PARK
;
Duck Young CHOI
;
Young Seob CHUNG
;
Kyu Chang WANG
;
Byung Kyu CHO
;
Kil Soo CHOI
- Publication Type:Original Article
- Keywords:
Arachidonic acid;
Infusion brain edema;
Somatosensory evoked potential;
Central conduction time;
Regional cerebral blood flow;
Water content
- MeSH:
Adult;
Animals;
Arachidonic Acid*;
Brain Edema;
Brain*;
Cats;
Edema;
Evoked Potentials, Somatosensory*;
Freeze Drying;
Humans;
Hydrogen;
Magnetic Resonance Imaging;
Median Nerve;
Neurologic Manifestations;
Vacuum
- From:Journal of Korean Neurosurgical Society
1991;20(1-3):91-107
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
To elucidate the funcion of arachidonic acid as a secondary brain edema facotr, the infusion edema model was constucted using adult cats with studies of somatosensory evoked potentials, regional cerebral blood flow of white matters, brain water contents, magentic resonance images and histological findings. Among 50 cats, 6 cats were used as sham poerated group without infustion and in 45 cats solutions of various concentrations of arachidonic acid and physiologic saline were infused into the left and right frontal white maters respectively. According to the different concentrations of arachidonic acid, three groups were named as group A(0.1mg/ml), group B(1mg/ml), group C(10mg/ml). During 4 hours of slow infusion of the infusates(average 0.5ml in each side totally) central conduction time(CCT) was measured every an hour with contralateral median nerve stimulation bilaterally and cerebral blood flow(CBF) of white matter was measured by hydrogen clearance method every 2 hours. Finally the cats were sacrificed and specimens of edematous white matter obtained bilaterally at the coresponding points. Water contents were measured with vacuum freeze drying method. T2-weighted magnectic resonance images(MRI) and light microscopic studies were performed in a cat of each groups. The results were as followed ; 1) MRI and histologic findings showed that the infusion brain edema technique was efective in inducing interstitial edema, but the differences in the degree of edema formation between the right and the left sides were not siginificant in all groups. 2) There were no statistically significant difference between the water contents of the right and that of left in all groups. 3) Either infusion of arachidonic acid or physiologic saline in the white matter did not change regional white matter CBF in all groups. 4) The I-N1 interpeak latency was labelled as central conduction time(CT), and the baseline CCT was 5.83+/-0.52msec. 5) The differences of CCT between infusion group and noninfusion group were statistically significant in group C at 2, 3, 4hours(p>0.01) and the differerences of cct between arachidonic acid and physiologic saline infustion sites were statistically significant in group B at 4 hors, group C at 1 hour(p>0.05) and group C at 2, 3, 4hours(p>0.01) after eginning of infusion and the differences increased with time in group C(p>0.01). The results indicate that arachidonic acid does not have edemogenic properties during 4 hours infusion but may induce neurologic dysfunction as to increase the CCT in somatosensory evoked potential studies if it exists in the edema fluid of brain white matter.
