An experimental study of the biomechanics of the middle cerebral artery in acute cerebral infarction

Local cerebrovascular paralysis was found in most cases of cerebral infaction. The extent and severity of vascular paralysis and its effect on contraction-relaxation function of vessels were dependent on the developmental rapidity and duration of vascular

Predictors of short-term outcome in patients with acute middle cerebral artery occlusion: unsuitability of fluid-attenuated inversion recovery vascular hyperintensity scores

Fluid-attenuated inversion recovery （FLAIR） vascular hyperintensity （FVH） is used to assess leptomeningeal collateral circulation, but clinical outcomes of patients with FVH can be very different. The aim of the present study was to assess a FVH score and explore its relationship with clinical outcomes. Patients with acute ischemic stroke due to middle cerebral artery M1 occlusion underwent magnetic resonance imaging and were followed up at 10 days （National Institutes of Health Stroke Scale） and 90 days （modified Rankin Scale） to determine short-term clinical outcomes. Effective collateral circulation indirectly improved recovery of neurological function and short-term clinical outcome by extending the size of the pial penumbra and reducing infarct lesions. FVH score showed no correlation with 90-day functional clinical outcome and was not sufficient as an independent predictor of short-term clinical outcome.

Is decompressive craniectomy for malignant middle cerebral artery infarction of any worth?

Objective: Malignant middle cerebral artery (MCA) infarction is characterized by mortality rate of up to 80%. The aim of this study was to determine the value of decompressive craniectomy in patients presenting malignant MCA infarction compared with those receiving medical treatment alone. Methods: Patients with malignant MCA infarction treated in our hospital between January 1996 and March 2004 were included in this retrospective analysis. The National Institute of Health Stroke Scale (NIHSS)was used to assess neurological status on admission and at one week after surgery. All patients were followed up for assessment of functional outcome by the Barthel index (BI) and modified Rankin Scale (RS) at 3 months after infarction. Results: Ten out of 24patients underwent decompressive craniectomy. The mean interval between stroke onset and surgery was 62.10 h. The mortality was 10.0% compared with 64.2% in patients who received medical treatment alone (P<0.001). The mean NIHSS score before surgery was 26.0 and 15.4 after surgery (P<0.001). At follow up, patients who underwent surgery had significantly better outcome with mean BI of 53.3, RS of 3.3 as compared to only 16.0 and 4.60 in medically treated patients. Speech function also improved in patients with dominant hemispherical infarction. Conclusion: Decompressive craniectomy in patients with malignant MCA infarction improves both survival rates and functional outcomes compared with medical treatment alone. A randomized controlled trial is required to substantiate those findings.

Different effects of mechanical embolus removal and intra-arterial thrombolysis on neural functional recovery in patients with acute middle cerebral artery occlusion

Objective:To study the different effects of mechanical embolus removal and intra-arterial thrombolysis on neural functional recovery in patients with acute middle cerebral artery occlusion.Methods: Patients with acute middle cerebral artery occlusion who were treated in the First Hospital of Yulin between September 2013 and October 2017 were selected and retrospectively studied, and the differences in reperfusion therapies in history data were referred to divide them into study group A and study group B who underwent mechanical embolus removal and intra-arterial thrombolysis respectively. The levels of neurocyte damage markers, apoptosis markers and stress markers in serum as well as the expression of Wnt pathway molecules in peripheral blood were determined before treatment and 24 h after treatment.Results: Compared with those of same group before treatment, serum NSE, S100B, VILIP1, sFas, sFasL, ET-1 and MDA levels as well as peripheral blood GSK3β, LC3-II and Beclin1 expression intensity of both groups were decreasing whereas serum BDNF, NTF, sLivin and SOD levels as well as peripheral bloodβ-catenin and mTOR expression intensity were increasing, and serum NSE, S100B, VILIP1, sFas, sFasL, ET-1 and MDA levels as well as peripheral blood GSK3β, LC3-II and Beclin1 expression intensity of study group A after treatment were lower than those of study group B whereas serum BDNF, NTF, sLivin and SOD levels as well as peripheral bloodβ-catenin and mTOR expression intensity were higher than those of study group B.Conclusion: Mechanical embolus removal for acute middle cerebral artery occlusion can be more effective than intra-arterial thrombolysis to reduce the nerve function damage as well as the corresponding oxidative stress and apoptosis.

Therapeutic effects of different durations of acupuncture on rats with middle cerebral artery occlusion

Acupuncture is regarded as an effective therapy for cerebral ischemia. Different acupuncture ma- nipulations and durations may result in different therapeutic effects. In the present study, the Neig uan （PC6） acupoint of rats with occluded middle cerebral arteries was needled at a fixed frequency （3 Hz） with different durations, i.e., 5, 60 and 180 seconds under a twisting-rotating acupuncture method. Results showed that different durations of acupuncture had different therapeutic effects, with 60 seconds yielding a better therapeutic effect than the other two groups. This duration of treatment demonstrated rapid cerebral blood flow, encouraging recovery of neurological function, and small cerebral infarct volume. Experimental findings indicated that under 3 Hz frequency, the treatment of needling Neiguan for 60 seconds is effective for ischemic stroke.

Modified constraint-induced movement therapy alters synaptic plasticity of rat contralateral hippocampus following middle cerebral artery occlusion

Modified constraint-induced movement therapy is an effective treatment for neurological and motor impairments in patients with stroke by increasing the use of their affected limb and limiting the contralateral limb.However,the molecular mechanism underlying its efficacy remains unclear.In this study,a middle cerebral artery occlusion(MCAO)rat model was produced by the suture method.Rats received modified constraint-induced movement therapy 1 hour a day for 14 consecutive days,starting from the 7^th day after middle cerebral artery occlusion.Day 1 of treatment lasted for 10 minutes at 2r/min,day 2 for 20 minutes at 2 r/min,and from day 3 onward for 20 minutes at 4 r/min.CatWalk gait analysis,adhesive removal test,and Y-maze test were used to investigate motor function,sensory function as well as cognitive function in rodent animals from the 1st day before MCAO to the 21^st day after MCAO.On the 21^st day after MCAO,the neurotransmitter receptor-related genes from both contralateral and ipsilateral hippocampi were tested by micro-array and then verified by western blot assay.The glutamate related receptor was shown by transmission electron microscopy and the glutamate content was determined by high-performance liquid chromatography.The results of behavior tests showed that modified constraint-induced movement therapy promoted motor and sensory functional recovery in the middle cerebral artery-occluded rats,but had no effect on cognitive function.The modified constraint-induced movement therapy upregulated the expression of glutamate ionotropic receptor AMPA type subunit 3(Gria3)in the hippocampus and downregulated the expression of the beta3-adrenergic receptor gene Adrb3 and arginine vasopressin receptor 1 A,Avprla in the middle cerebral artery-occluded rats.In the ipsilateral hippocampus,only Adra2 a was downregulated,and there was no significant change in Gria3.Transmission electron microscopy revealed a denser distribution the more distribution of postsynaptic glutamate receptor 2/3,which is an a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor,within 240 nm of the postsynaptic density in the contralateral cornu ammonis 3 region.The size and distribution of the synaptic vesicles within 100 nm of the presynaptic active zone were unchanged.Western blot analysis showed that modified constraint-induced movement therapy also increased the expression of glutamate receptor 2/3 and brain-derived neurotrophic factor in the hippocampus of rats with middle cerebral artery occlusion,but had no effect on Synapsin I levels.Besides,we also found modified constraint-induced movement therapy effectively reduced glutamate content in the contralateral hippocampus.This study demonstrated that modified constraint-induced movement therapy is an effective rehabilitation therapy in middle cerebral artery-occluded rats,and suggests that these positive effects occur via the upregulation of the postsynaptic membrane a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor expression.This study was approved by the Institutional Animal Care and Use Committee of Fudan University,China(approval No.201802173 S)on March 3,2018.

An enriched environment promotes synaptic plasticity and cognitive recovery after permanent middle cerebral artery occlusion in mice

Cerebral ischemia activates an endogenous repair program that induces plastic changes in neurons. In this study, we investigated the effects of environmental enrichment on spatial learning and memory as well as on synaptic remodeling in a mouse model of chronic cerebral ischemia, produced by subjecting adult male C57 BL/6 mice to permanent left middle cerebral artery occlusion. Three days postoperatively, mice were randomly assigned to the environmental enrichment and standard housing groups. Mice in the standard housing group were housed and fed a standard diet. Mice in the environmental enrichment group were housed in a cage with various toys and fed a standard diet. Then, 28 days postoperatively, spatial learning and memory were tested using the Morris water maze. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 in the hippocampus were analyzed by western blot assay. The number of synapses was evaluated by electron microscopy. In the water maze test, mice in the environmental enrichment group had a shorter escape latency, traveled markedly longer distances, spent more time in the correct quadrant(northeast zone), and had a higher frequency of crossings compared with the standard housing group. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 were substantially upregulated in the hippocampus in the environmental enrichment group compared with the standard housing group. Furthermore, electron microscopy revealed that environmental enrichment increased the number of synapses in the hippocampal CA1 region. Collectively, these findings suggest that environmental enrichment ameliorates the spatial learning and memory impairment induced by permanent middle cerebral artery occlusion. Environmental enrichment in mice with cerebral ischemia likely promotes cognitive recovery by inducing plastic changes in synapses.

Screen-imaging guidance using a modified portable video macroscope for middle cerebral artery occlusion

The use of operating microscopes is limited by the focal length.Surgeons using these instruments cannot simultaneously view and access the surgical field and must choose one or the other.The longer focal length （more than 1 000 mm） of an operating telescope permits a position away from the operating field,above the surgeon and out of the field of view.This gives the telescope an advantage over an operating microscope.We developed a telescopic system using screen-imaging guidance and a modified portable video macroscope constructed from a Computar MLH-10 × macro lens,a DFK-21AU04 USB CCD Camera and a Dell laptop computer as monitor screen.This system was used to establish a middle cerebral artery occlusion model in rats.Results showed that magnification of the modified portable video macroscope was appropriate （5-20 ×） even though the Computar MLH-10 × macro lens was placed 800 mm away from the operating field rather than at the specified working distance of 152.4 mm with a zoom of 1-40 ×.The screen-imaging telescopic technique was clear,life-like,stereoscopic and matched the actual operation.Screen-imaging guidance led to an accurate,smooth,minimally invasive and comparatively easy surgical procedure.Success rate of the model establishment evaluated by neurological function using the modified neurological score system was 74.07%.There was no significant difference in model establishment time,sensorimotor deficit and infarct volume percentage.Our findings indicate that the telescopic lens is effective in the screen surgical operation mode referred to as ＂long distance observation and short distance operation＂ and that screen-imaging guidance using an modified portable video macroscope can be utilized for the establishment of a middle cerebral artery occlusion model and micro-neurosurgery.

Effect of Fujian tablet on the expression of Nogo-A mRNA in the cervical spinal cord of middle cerebral artery occlusion model rats

Inhibiting the expression of Nogo-A in cervical spinal cord by use of interaction of antigen and antibody can help the remodeling of corticospinal projection of focal cerebral ischemia model rats to facilitate neurological recovery, which provides a new possible mechanism for drugs to promote neurological recovery. However, the effects of drugs on the expression of Nogo-A in cervical spinal cord are still unclear. OBJECTIVE： To observe the effect of Fujian tablet on the expression of Nogo-A mRNA in cervical spinal cords of middle cerebral artery occlusion （MCAO） rats, and to investigate the possible regulatory effect of Fujian tablet on the regenerated microenvironment of spinal conduction bundle. DESIGN： A randomized and controlled trial taking Wistar rats as experimental animals. SETTING： Department of Neurology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine. MATERIALS： This experiment was carried out in the laboratory of Shandong Academy of Medical Science between June 2005 and July 2006. A total of 40 healthy male Wistar rats, aged 12 weeks, weighing 250 - 300 g, were provided by the Experimental Animal Center of Shandong University. Fujian tablets （main components： Heshouwu, Yinyanghuo, etc） were provided by office of Pharmaceutics of Shandong University of traditional Chinese medicine. Nogo-A detection kit was provided by Wuhan Boster Biotechnology Co.,Ltd., and batch number was 040309009. This experiment was approved by Local Animal Ethics Committee. METHODS： Forty male rats were randomly divided into 4 groups, with 10 in each： normal group, sham-operation group, model group and administration group. Rats in the administration group and model group were subjected to MCAO. Rats in the sham-operation group underwent the same craniotomy, and their middle cerebral arteries （MCA） were not occluded. Rats in the normal group were untouched. Rats in administration group were intragastrically administrated with the solution of Fujian tablet at a dose of 9 g/kg and others were given equal dosage of normal saline two days later. The treatments were done once a day and the course totaled 2 weeks. MAIN OUTCOME MEASURES： The expression of Nogo-A mRNA in slices of cervical spinal cords. RESULTS： Forty rats were involved in the final analysis. The expression of Nogo-A mRNA in the cervical spinal cord of rats in the administration group and model group was significantly decreased as compared with that in the normal group （P 〈 0.01 and P 〈 0.05, respectively）. The expression of Nogo-A mRNA in the administration group was also significantly weaker than that in the model group （P 〈 0.05 ） . CONCLUSION： Fujian tablet can inhibit the expression of Nogo-A mRNA in cervical spinal cords of MCAO rats, which facilitates regeneration and remodeling of cervical spinal cords.

In vivo tracking of human adipose-derived stem cells labeled with ferumoxytol in rats with middle cerebral artery occlusion by magnetic resonance imaging

Ferumoxytol, an iron replacement product, is a new type of superparamagnetic iron oxide ap- proved by the US Food and Drug Administration. Herein, we assessed the feasibility of tracking transplanted human adipose-derived stem cells labeled with ferumoxytol in middle cerebral artery occlusion-injured rats by 3.0 T MRI in vivo. 1 × 104 human adipose-derived stem cells labeled with ferumoxytol-heparin-protamine were transplanted into the brains of rats with middle cerebral artery occlusion. Neurologic impairment was scored at 1, 7, 14, and 28 days after transplantation. T2-weighted imaging and enhanced susceptibility-weighted angiography were used to observe transplanted cells. Results of imaging tests were compared with results of Prussian blue staining. The modified neurologic impairment scores were significantly lower in rats transplanted with cells at all time points except I day post-transplantation compared with rats without transplantation. Regions with hypointense signals on T2-weighted and enhanced susceptibility-weighted angiography images corresponded with areas stained by Prussian blue, suggesting the presence of superparamagnetic iron oxide particles within the engrafted cells. Enhanced susceptibility-weighted angiography image exhibited better sensitivity and contrast in tracing ferumoxytol-heparin-protamine-labeled human adipose-derived stem ceils compared with T2-weighted imaging in routine MRI.

Motor outcomes of patients with a complete middle cerebral artery territory infarct

Detailed knowledge of motor outcomes enables to establish proper goals and rehabilitation strate-gies for stroke patients. Several previous studies have reported functional or motor outcomes in patients with a middle cerebral artery territory infarct. However, little is known about motor outcome in patients with a complete middle cerebral artery territory infarct. In this study, we investigated the motor outcomes in 23 patients with a complete middle cerebral artery territory infarct. All of these patients received comprehensive rehabilitative management, including movement therapy and neuromuscular electrical stimulation of the affected finger extensors and ankle dorsiflexors, for more than 3 months. Motor outcomes were measured at 6 months after stroke onset using the Medical Research Council, Motricity Index, the modified Brunnstrom Classification, and Functional Ambula-tion Category scores. The motor function of the lower extremities was found to be better than that of the upper extremities. After receiving rehabilitation treatments for 3–6 months, about 70% of these patients were able to walk independently （Functional Ambulation Category scores 3）, but no pa-tient achieved functional hand recovery.

Apparent diffusion coefficient evaluation for secondary changes in the cerebellum of rats after middle cerebral artery occlusion

Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffu- sion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially in- creased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion co- efficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3-24 hours after infarction. Apparent diffusion coefficient values at remote regions （cerebellum） varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis.

INTRANASAL DELIVERY OF NERVE GROWTH FACTOR TO PROTECT THE CENTRAL NERVOUS SYSTEM AGAINST ACUTE CEREBRAL INFARCTION

Objective To confirmed reliability and feasibility of intranasal nerve growth factor (NGF) bypassing the blood-brain barrier and its potential neuroprotective effects on acute cerebral ischemia. Methods (1) To assay NGF concentrations in different brain regions after middle cerebral artery occlusion (MCAO).Rats were randomly divided into intranasal (IN) NGF, intravenous (IV) NGF, and untreated group (n= 4). The concentra-tions of NGF of different brain regions in the three groups after MCAO were measured by ELISA. (2) To observe neuro-protective action of NGF on focal cerebral ischemic damage. Rats were randomly assigned to 4 groups: IN vehicle, IN NGF, IV vehicle, IV NGF (n= 8). Treatment was initiated 30 minutes after onset of MCAO and given again 24 hours later. Three neurologic behavioral tests were performed 24 and 48 hours following onset of MCAO. Corrected infarct volumes were determined 48 hours after onset of MCAO. Results The olfactory bulb in IN NGF group obtained the highest concentration (3252 pg/g) of NGF among all regions, followed by the hippocampus. The NGF concentrations in the olfactory bulb and hippocampus in IN NGF group were markedly higher than that in IV NGF and control groups. The infarct volume in IN NGF group was markedly reduced by 38.8% compared with IN vehicle group. IN NGF group vestibulum function markedly improved compared with IN vehicle group at 24 and 48 hours after onset of MCAO (P 24 h = 0.02 and P 48 h = 0.04, respectively). Conclusion Intranasal NGF could pass through the blood-brain barrier, reach the central nervous system, reduce infarct volume, and improve neurologic function in rats following MCAO. Intranasal delivery of NGF may be a promising treat-ment for stroke.

Effects of Echinacoside on Histio-central Levels of Active Mass in Middle Cerebral Artery Occlusion Rats

Objective To investigate the effects of echinacoside on the extracellular striatal levels of norepinephrine（NE）,dopamine（DA）,homovanillic acid（HVA）,3,4-dihydroxyphenylethanoid acid（DOPAC）,5-hydroxyindoleacetic acid（HIAA）,and 5-hydroxytryptamine（5-HT） in middle cerebral artery occlusion（MCAO rats.Methods The middle cerebral artery was occluded in male Sprague-Dawley rats.Three days later microdialysis probes were placed into the right striatum of MCAO rat brains and the brains were perfused with Ringer＇s solution at a rate of 1.5 μL/min.Cerebral microdialysates were collected every 30 minutes from awake and freely moving rats before assaying for NE,DA,HVA,DOPAC,HIAA,and 5-HT levels by reverse phase HPLC with electrochemistry.Results Three days after MCAO,the extracellular striatal levels of NE,DA,DOPAC,HIAA,HVA,and 5-HT of the MCAO rats increased significantly（at least P0.05 vs.control）.However,simultaneous treatment with echinacoside（30.0 or 15.0 mg/kg） attenuated these increases（at least P0.05 vs.non-treated model rats）.Conclusion These results imply that echinacoside may protect striatal dopa minergic neurons from the injury induced by MCAO and may help prevent and treat cerebral ischemic diseases.

Bilateral cerebral infarction in diabetic ketoacidosis and bilateral internal carotid artery occlusion:A case report and review of literature

BACKGROUND Diabetic ketoacidosis(DKA)is a serious complication of type 1 diabetes mellitus(T1DM).Very rarely does DKA lead to cerebral edema,and it is even rarer for it to result in cerebral infarction.Bilateral internal carotid artery occlusion(BICAO)is also rare and can cause fatal stroke.Moreover,case reports about acute cerebral infarction throughout both internal carotid arteries with simultaneous BICAO are very scarce.In this study,we present a patient with BICAO,T1DM,hypertension,and hyperlipidemia,who had a catastrophic bilateral cerebral infarction after a DKA episode.We briefly introduce BICAO and the mechanisms by which DKA results in cerebral infarction.CASE SUMMARY A 41-year-old woman presented with ischemic stroke that took place 3 mo prior over the left corona radiata,bilateral frontal lobe,and parietal lobe with right hemiplegia and Broca’s aphasia.She had a history of hypertension for 5 years,hyperlipidemia for 4 years,hyperthyroidism for 3 years,and T1DM for 31 years.The first brain magnetic resonance imaging not only revealed the aforementioned ischemic lesions but also bilateral internal carotid artery occlusion.She was admitted to our ward for rehabilitation due to prior stroke sequalae.DKA took place on hospital day 2.On hospital day 6,she had a new massive infarction over the bilateral anterior cerebral artery and middle cerebral artery territory.After weeks of aggressive treatment,she remained in a coma and on mechanical ventilation due to respiratory failure.After discussion with her family,compassionate extubation was performed on hospital day 29 and she died.CONCLUSION DKA can lead to cerebral infarction due to several mechanisms.In people with existing BICAO and several stroke risk factors such as hypertension, T1DM,hyperlipidemia, DKA has the potential to cause more serious ischemic strokes.

Neuroprotective effect of Longshengzhi capsule following permanent middle cerebral artery occlusion in rats

Objective:Longshengzhi capsule(LSZC)is an optimized preparation based on the traditional Chinese Medicine formula Buyanghuanwu Decoction(BYHWD),and is approved by the China Food and Drug Administration for treating stroke-induced disability and vascular diseases.Herein,we examined the pharmacodynamics,anti-apoptotic and anti-oxidant actions,and potential mechanisms of action of LSZC following stroke in rats.Methods:Permanent middle cerebral artery occlusion(MCAO)was used as an ischemic stroke model.LSZC was administered intragastrically.We examined the survival rate,bodyweight,and neurological deficits in stroke rats.Brain infarct size was determined by 2,3,5-triphenyltetrazolium chloride staining.Brain pathology was examined using hematoxylin and eosin staining,Nissl staining,and TdT-mediated dUTP Nick-End Labeling staining.Malondialdehyde,catalase,superoxide dismutase,and glutathione levels were examined by commercial kits.Expression of Nrf2,heme oxygenase-1,Bax,Bcl-2,cleaved caspase-3,and caspase-3 proteins in brain tissue was measured by Western blot.Results:LSZC markedly improved the survival rate and bodyweight,and reduced infarct volume and neurological deficit scores,in MCAO stroke rats.LSZC also significantly attenuated oxidative stress,as indicated by decreased expression of malondialdehyde,and upregulation of Nrf2,heme oxygenase-1,catalase,superoxide dismutase,and glutathione.Moreover,LSZC significantly decreased apoptosis,including a decrease in Bax and cleaved caspase-3 expression,and an increase in Bcl-2,as well as a reduction in numbers of apoptotic neurons.Conclusion:LSZC treatment is neuroprotective against ischemic stroke,potentially via reducing oxidative stress and apoptosis.The Nrf2 and apoptotic signaling pathways may play important roles in the antioxidant and anti-apoptotic actions of LSZC.

Neuroprotective effect of high-dose hyperbaric oxygenation on rats with acute cerebral infarction in super-early stage:Curative comparison between 9-hour and 18-hour therapeutic protocols

BACKGROUND： Previously, only single short-time low-dose hyperbaric oxygenation （HBO） protocol was administrated to treat acute ischemic stroke in early stage and the conflicting results were obtained. There are few studies to report the outcome of administering long-time （can cover all the natural pathologic progression period） high-dose HBO to treat the disease. OBJECTIVE： To evaluate the therapeutic effect between two kinds of high-dose hyperbaric oxygenation on super-early stage of acute permanent middle cerebral artery occlusion （MCAO） in rats. DESIGN： A randomized controlled experimental study. SETTING： Beijing Tiantan Hospital, Capital Medical University; Beijing Research Institute of Neurosurgery. MATERIALS： Seventy-four male SD rats, aged 2.5 months old, weighing （ 280 ＋ 20） g, were provided by the Animal Institute, Chinese Academy of Medical Sciences. Hyperbaric oxygenation device was hyperbaric air cabin in which there was a self-made pure oxygen animal experimental cabin （made in China）. METHODS： This experiment was carried out in the municipal laboratory of Beijing Tiantan Hospital affiliated to Capital Medical University and Beijing Research Institute of Neurosurgery. ① Experimental intervention： All the rats were developed into models of permanent MCAO by suture embolism. Then, they were randomly divided into two HBO groups （9 hours and 18 hours） and control group, with 24 rats in each as well as 3-hour ultrastructure control group, with 2 rats. After being modeled for 3 hours, rats in the two HBO groups stayed in the hyperbaric cabin for 9 hours and 18 hours, separately. Rats in the 9-hour HBO group inhaled pure oxygen at hours 1, 3, 5, 7 and 9, and hyperbaric air at hours 2, 4, 6 and 8. Rats in the 18-hour HBO group inhaled pure oxygen at hours l, 3, 5, 7, 9, 11, 13, 15 and 17, and hyperbaric air at hours 2, 4, 6, 8, l0 12, 14, 16 and 18. After being created into models, rats in the control group and 3-hour ultrastructure control group breathed room air. ② Experimental evaluation： Neurologic functions of rat models in the 9-hour and 18-hour HBO groups as well as control group were scored by Bederson and Garica two neurological grading systems at hours 14 and 28 and on day 5; Infarct volume of rat models in the two HBO groups and control group was measured at hour 24 and on day 5 with NIH image processing software Image J; The pathological changes of brain tissue in the brain infarct region and its opposite region of rat models in the two HBO groups and 3-hour ultrastructure control group were observed with a Philips EM 208S transmission electron microscope. MAIN OUTCOME MEASURES： ① Neurobehavioral outcome. ② Rat brain infarct volume. ③ Ultrastructure of brain tissue in the ischemic penumbra of infarct models at the different time points RESULTS： ① Neurobehavioral outcome： After treatment, Garica score in the 9-hour and 18-hour HBO groups was significantly higher than that in the control group （P 〈 0.01）. Bederson score on day 5 after modeling in the 9-hour and 18-hour HBO groups was significantly lower than that in the control group （P 〈 0.01）. ② Cerebral infarct volume： Cerebral infarct volume in the 9-hour and 18-hour HBO groups was significantly smaller than that in the control group at hour 24 and on day 5 after modeling （P 〈 0.01）. In the 18-hour HBO group, infarct volume on day 5 after modeling was significantly larger than that at hour 24 after modeling （P 〈 0.05）. ③In the 3-hour ultrastructure control group, astrocyte edema and neuron damage around the capillary in the infarct cerebral tissue significantly relieved in the rats which were subjected to HBO. CONCLUSION： High dose of HBO is highly efficient in reducing infarct volume and improving neurobehavioral outcome of rats with acute cerebral infarction, and also has an important role in inhibiting the pathological progression of ischemic brain tissue after cerebral infarction.

Occlusion of the middle cerebral artery Guidance by screen imaging using an EDA-H portable medium-soft electronic endoscope

The present study aimed to verify the practicability of performing screen-based surgical operations under the guidance of a real-time viewing and recording system （RTVRS） using a portable medium-soft electronic endoscope （pmsEE）. The middle cerebral artery in rats was occluded under screen-imaging guidance using a pmsEE RTVRS to reproduce an animal model of human cerebral infarction. The screen imaging of the pmsEE RTVRS was clear, life-like, stereoscopic and synchronous with the actual operation. Screen-imaging guidance led to an accurate, smooth, minimally invasive and comparatively easy surgical procedure. The surgical success rate, time of model establishment, neurological function scores, and infarct volume were similar to those using an operating microscope. These results indicate that the self-designed pmsEE RTVRS could be utilized for portable endoscopic screen-based surgical operations.

Middle cerebral artery occlusion methods in rat versus mouse model of transient focal cerebral ischemic stroke

Experimental stroke research commonly employs focal cerebral ischemic rat models （Bederson et al., 1986a; Longa et al., 1989）. In human patients, ischemic stroke typically results from thrombotic or embolic occlusion of a major cerebral artery, usually the mid- dle cerebral artery （MCA）. Experimental focal cerebral ischemia models have been employed to mimic human stroke （Durukan and Tatlisumak, 2007）. Rodent models of focal cerebral ischemia that do not require craniotomy have been developed using intraluminal suture occlusion of the MCA （MCA occlusion, MCAO） （Rosamond et al., 2008）. Furthermore, mouse MCAO models have been wide- ly used and extended to genetic studies of cell death or recovery mechanisms （Liu and McCullough, 2011）. Genetically engineered mouse stroke models are particularly useful for evaluation of isch- emic pathophysiology and the design of new prophylactic, neuro- protective, and therapeutic agents and interventions （Armstead et al., 2010）. During the past two decades, MCAO surgical techniques have been developed that do not reveal surgical techniques for mouse MCAO model engineering. Therefore, we compared MCAO surgical methods in rats and mice.

Combined surgical and interventional treatment of tandem carotid artery and middle cerebral artery embolus: A case report

BACKGROUND The 2018 American Heart Association/American Stroke Association guidelines for early management of acute ischemic stroke recommend the use of retrievable stents for mechanical thrombectomy in patients with acute internal carotid artery or middle cerebral artery M1 occlusion that can be treated within 6 h from onset.For cases of carotid artery with ipsilateral middle cerebral artery tandem embolization, the operation is more complicated and challenging. We here report a case of a tandem embolism, and the anatomy of the aortic arch was complex.Direct carotid artery incision and thrombectomy can not only prevent the escape of the carotid embolus but also save time during establishment of the thrombectomy access.CASE SUMMARY The patient was a 70-year-old man. He was admitted to hospital due to sudden inability to speak and inability to move his right limb for 3 h. Imaging confirmed a diagnosis of a tandem embolism in the left carotid artery with left M1 occlusion.Carotid artery incision thrombectomy combined with stent thrombectomy was performed. The operation was successful, and 24 h later the patient was conscious and mentally competent but had motor aphasia. His bilateral limb muscle strength level was 5, and his neurologic severity scores score was 2.CONCLUSION Carotid artery incision thrombectomy combined with stenting for carotid artery plus cerebral artery tandem embolization is clinically feasible. For patients with a complicated aortic arch and an extremely tortuous carotid artery, carotid artery incision can be chosen to establish the interventional path.