The Use of Somatosensory Evoked Potential Monitoring to Produce a Canine Model of Uniform, Moderately Severe Stroke with Permanent Arterial Occlusion

Abstract

To develop a reliable canine model of cerebral infarction of moderate size, we compared infarctions caused by permanent occlusion of the following vessels in 42 dogs: 1) the middle cerebral artery (MCA), 2) the MCA and azygous anterior cerebral artery (ACA), 3) the MCA, azygous ACA, and posterior cerebral artery (PCA), and 4) sham-operated controls. The infarction volume was determined at 6 hours in half the animals and at 6 days in the others. Studies of somatosensory evoked potentials (SSEPs) and regional cerebral blood flow (rCBF) were performed before and after arterial occlusion, and good correlation was observed between the decrease in amplitude of the SSEPs and the decrease in rCBF observed after arterial occlusion. Only the groups in which the MCA and azygous ACA were occluded showed moderate infarctions of relatively consistent size. Analysis involving all groups revealed that the animals with SSEP amplitude preserved after vessel occlusion had only small infarctions; thus, preservation of SSEP amplitude after occlusion of the MCA and azygous ACA could in the future be used prospectively as a rejection criterion to improve the uniformity of infarction size. Conversely, animals with loss of SSEP amplitude after vessel occlusion had infarctions of moderate to large size; thus, loss of SSEP amplitude after MCA occlusion alone could in the future be used prospectively as a rejection criterion. When these rejection criteria were retrospectively applied to the groups in which both the MCA and azygous ACA were occluded, the resulting mean infarction volumes +/- 1 SEM) for the acute and chronic subgroups were 20.3 +/- 2.8% and 38.2 +/- 4.5% of the hemisphere, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in superoxide dismutase, glutathione peroxidase and catalase activities in experimental cerebral ischemia-reperfusion

“…It is because the change in SSEP amplitude correlates so well with CBF. When the attenuation of the SSEP amplitude is reversible one can predict a penumbral ischemia development [12,27]. To control the efficiency of the surgical procedure in producing the penumbra like conditions we used SSEP as a feedback parameter.…”

“…Amplitude changes were accepted as the indicator of the ischemia. At the end of 10 min of ischemia rats with a decrease of N1-P1 amplitudes less then 50% [18,27] of preischemic values were excluded from the study.…”

“…SSEPs recordings analyses at 5 min of CCA occlusion showed a slight decrease in N1-P1 waves (first negative peak and first positive peak) amplitude from the preischemic baseline values. The analyses of the 10 min SSEPs amplitudes showed that animals with four vessel occlusion had 42±3.4% of preischemic baseline values [27].…”

Large animals in neurointerventional research: A systematic review on models, techniques and their application in endovascular procedures for stroke, aneurysms and vascular malformations

“…Large animal strains are often outbred, increasing the likelihood of such variances. For instance, collateral vasculature or tortuous blood vessels as observed in pigs, 76 dogs, 75 and cats 139 can cause challenges in experimental interventions. Moreover, some species-specific anatomic prerequisites must be taken into consideration, the most prominent one being the RM.…”