Branch Of Middle Cerebral Artery Research Articles

Factors predicting poor outcome at discharge in stroke patients with middle cerebral artery branch occlusion

ObjectivesTo better determine the usefulness of mechanical thrombectomy for stroke patients with middle cerebral artery (MCA) branch occlusion, we investigated predictive factors related to poor outcome in acute, MCA branch occlusion stroke patients who had not undergone mechanical thrombectomy. Patients and methodsWe retrospectively evaluated 204 consecutive acute stroke patients with MCA branch (M2-M4) occlusion. Two groups, based on activity of daily living scores at discharge, were compared: a dependent outcome group (mRS 3–6; n = 109) and an independent outcome group (mRS 0–2; n = 95), and the factors related to dependent outcomes at discharge determined. ResultsThe dependent group was older, had higher National Institutes of Health Stroke Scale (NIHSS) scores on admission, higher serum D-dimer and brain natriuretic peptide levels, and lower Alberta Stroke Program Early CT scores (ASPECTS) and rates of intravenous thrombolysis than the independent group. In multivariate analysis, age (OR 1.06; 95%CI 1.03–1.10), admission NIHSS score (OR 1.12; 95%CI 1.05–1.19), ASPECTS (OR 0.56; 95%CI 0.40–0.79), and intravenous thrombolysis (OR 0.22; 95%CI 0.08–0.57) were related to dependent outcomes. Decision curve analysis demonstrated that admission NIHSS scores were better predictors of dependency for threshold probabilities from 0.25 to 0.46. The optimal cutoff scores for predicting dependency were ≥8 (sensitivity 0.76, specificity 0.62) for the admission NIHSS score. ConclusionsAdmission NIHSS scores might be useful predictors of dependent outcomes at discharge in acute ischemic stroke patients with MCA branch occlusion.

A murine photothrombotic stroke model with an increased fibrin content and improved responses to tPA-lytic treatment

The Rose Bengal (RB) dye-based photothrombotic stroke (PTS) model has many methodological advantages including consistent location and size of infarct, low mortality, and relatively simple surgical procedures. However, the standard PTS has the caveat of poor responses to tissue-type plasminogen activator (tPA)-mediated lytic treatment, likely as a result of the platelet-rich, fibrin-poor content of the blood clots. Here we tested whether the admixture of thrombin (80 U/kg) and RB dye (50 mg/kg) in the proximal middle cerebral artery (MCA)-targeted PTS will modify the clot composition and elevate the responsiveness to tPA-lytic treatment (Alteplase, 10 mg/kg). Indeed, intravital imaging, immunostaining, and immunoblot analyses showed less-compacted platelet aggregates with a higher fibrin content in the modified thrombin (T) plus RB photothrombotic stroke (T+RB-PTS) model compared with the standard RB-PTS-induced clots. Both RB-PTS and T+RB-PTS showed steady recovery of cerebral blood flow (CBF) in the ischemic border from 1 day after infarction, but without recanalization of the proximal MCA branch. Intravital imaging showed high potency of restoring the blood flow by tPA after single vessel-targeted T+RB-PTS. Further, although intravenous tPA failed to restore CBF or attenuate infarction in RB-PTS, it conferred 25% recovery of CBF and 55% reduction of the infarct size in T+RB-PTS (P < .05) if tPA was administered within 2 hours postphotoactivation. These results suggest that T+RB-PTS produces mixed platelet:fibrin clots closer to the clinical thrombus composition and enhanced the sensitivity to tPA-lytic treatment. As such, the modified photothrombosis may be a useful tool to develop more effective thrombolytic therapies of cerebral ischemia.

Ghost Aneurysms in Acute Subdural Hematomas: A Report of Two Cases

Acute subdural hematoma (aSDH) is a common pathology encountered in neurosurgery. Although most cases are associated with trauma and injuries to draining veins, traumatic aSDH from injury to arteries or spontaneous aSDH because of a ruptured intracranial aneurysm can occur. For some patients without a clear clinical history, it can be difficult to distinguish between these etiologies purely based on radiography. The objective of this research was to describe a case series in which imaging was suggestive of the presence of distal cortical intracranial aneurysm associated with aSDH, but operative management demonstrated no evidence of aneurysm. We retrospectively reviewed 2 patients known to have aSDH with suspicion for associated aneurysm between May 2019 and September 2019 at our institution. Data collected included demographic, clinical, and operative course, including age, gender, past medical history, presenting symptoms, and pre and postoperative imaging. In 2 patients presenting with aSDH with preoperative radiographic imaging suggesting distal middle cerebral artery aneurysms, surgical exploration revealed no aneurysm. In both cases, noniatrogenic active arterial bleeding from an injured cortical middle cerebral artery branch was identified. Although there are prior reports of arterial aSDH, to our knowledge, this is the first to describe the radiographic "ghost aneurysm" sign. It is important for clinicians to be aware of this potential misleading radiographic sign, which indicates active extravasation into a spherical cast of clot.

Isolated Insular Stroke: Clinical Presentation

The symptoms related to insular ischemia have been the object of several studies in patients affected by stroke, although they are often accompanied by other ischemic alteration of adjacent brain structures supplied by the middle cerebral artery (MCA). The insula is vulnerable because of an ischemia due to thromboembolic vascular occlusion of the M1 MCA segment and the 2 main MCA branches (M2), mainly when they abruptly arise from the principal stem at a right angle. This topographical and anatomical peculiarity could enable an embolic formation, especially due to atrial fibrillation (AF), to occlude the transition pathway between M1 and M2, while the proximal origin of vascular supply protects the insula from ischemia due to hemodynamic factors. The aim of the study is to characterize the clinical aspects of acute ischemic strokes as a first event in the insular territory with specific attention to atypical manifestation. We have considered 233 patients with a first event stroke involving the insular territory and 13 cases of isolated insular stroke (IIS), from the stroke registry of the Policlinico “G.Martino”, University of Messina, between the February 10, 2014 and the February 7, 2018. IIS patients showed CT/MRI lesions restricted to the insular region. Exclusion criteria were coexisting neurological diseases, structural brain lesions, extension to the subinsular area >50% of the total infarct volume. We identified 13 IIS patients (mean age 74 years), with an isolated symptom or a combination of typical and atypical aspects. Furthermore, we observed high frequency detection of cardiac disturbances. To our knowledge, just a few previous studies have described IIS; their incidence is still not well defined. IIS manifested with a combination of deficits including motor, somatosensory, speaking, coordination, autonomic and cognitive disturbances. After an ischemic stroke, AF manifestation could follow briefly the major event and its duration could be very short, as an autonomic dysfunction due to an insular infarction. This clinical condition requires a continuous cardiac monitoring for this dangerous occurrence.

Study of pattern of origin of central branches of middle cerebral artery by using 64-slice computed tomography angiography

Background and Aims: Middle cerebral artery (MCA), a branch of the internal carotid artery, is the most commonly affected vessel in cerebrovascular diseases. Various studies have reported for variations in the origin pattern of MCA. The detection of these variations is of clinical relevance for the clinicians for planning their line of treatment. The present study was performed to identify the variations using 64-slice computed tomography (CT) angiography. Materials and Methods: The present study was performed in 45 participants (32 males and 13 females). MCA was identified and observed for a different pattern of origin of the central (perforating) branches using 64-slice CT angiography. Results: The observations revealed that the M1 segment of MCA showed single, dual, or multiple origins of central branches. Single central branch of MCA originated in 8.88% of cases, double branches were observed in 11.11% of cases, whereas the multiple branches were found in 66.67% of cases and mix pattern was observed in 13.3% of cases. These central branches coursed through the anterior perforating substance to reach the basal area of the subcortical zone. Conclusions: The present study revealed the variations in origin of the central branches of MCA using 64-slice CT angiography and the knowledge of radiological identification of these variations can be of use for radiologists and neurosurgeons dealing with cerebrovascular diseases.

Telemedicine-Guided Stroke Thrombolysis in a COVID-19 Patient Admitted in a Field Hospital

Telemedicine might be crucial during the current pandemic, helping in re-structuring the health system. This paper is a case report of a COVID-19 patient admitted to a field hospital who presented an infection-triggered ischemic stroke. She was examined by allocated general practitioners and had a life-threatening situation. The correct application of treatment guidelines is a challenge in this scenario and the feasibility of telemedicine-guided treatment is still uncertain. This report aims to demonstrate the effectiveness of teleconsultation in an emergency. There was a retrospective data compilation from the patient's medical record and subsequent exposure of the main findings. The patient presented typical viral pneumonitis on chest CT scan, she was on supportive treatment and presented acute neurological deficit on the tenth day after respiratory manifestation. Immediate skull CT scan did not show blood and there was stippling in sylvian branches of a left middle cerebral artery. There was telemedicine-guided confirmation of the diagnosis, tomographic interpretation, decision-making, and thrombolytic administration. There is a demonstration of the feasibility of teleconsultation in a time-effective manner, reinforcing the need to expand the telemedicine program in multiple scenarios.

Spatiotemporal dynamics of pial collateral blood flow following permanent middle cerebral artery occlusion in a rat model of sensory-based protection: a Doppler optical coherence tomography study.

.There is a growing recognition regarding the importance of pial collateral flow in the protection from impending ischemic stroke both in preclinical and clinical studies. Collateral flow is also a major player in sensory stimulation-based protection from impending ischemic stroke. Doppler optical coherence tomography has been employed to image spatiotemporal patterns of collateral flow within the dorsal branches of the middle cerebral artery (MCA) as it provides a powerful tool for quantitative in vivo flow parameters imaging (velocity, flux, direction of flow, and radius of imaged branches). It was employed prior to and following dorsal permanent MCA occlusion (pMCAo) in rat models of treatment by protective sensory stimulation, untreated controls, or sham surgery controls. Unexpectedly, following pMCAo in the majority of subjects, some MCA branches continued to show anterograde blood flow patterns over time despite severing of the MCA. Further, in the presence of protective sensory stimulation, the anterograde velocity and flux were stronger and lasted longer than in retrograde flow branches, even within different branches of single subjects, but stimulated retrograde branches showed stronger flow parameters at 24 h. Our study suggests that the spatiotemporal patterns of collateral-based dorsal MCA flow are dynamic and provide a detailed description on the differential effects of protective sensory stimulation.

Operculoinsular cortectomy for refractory epilepsy. Part 2: Is it safe?

Operculoinsular cortectomy (also termed operculoinsulectomy) is increasingly recognized as a therapeutic option for perisylvian refractory epilepsy. However, most neurosurgeons are reluctant to perform the technique because of previously experienced or feared neurological complications. The goal of this study was to quantify the incidence of basic neurological complications (loss of primary nonneuropsychological functions) associated with operculoinsular cortectomies for refractory epilepsy, and to identify factors predicting these complications. Clinical, imaging, and surgical data of all patients investigated and surgically treated by our team for refractory epilepsy requiring an operculoinsular cortectomy were retrospectively reviewed. Patients with tumors and encephalitis were excluded. Logistic regression analysis was used for uni- and multivariate statistical analyses. Forty-four operculoinsular cortectomies were performed in 43 patients. Although postoperative neurological deficits were frequent (54.5% of procedures), only 3 procedures were associated with a permanent significant neurological deficit. Out of the 3 permanent deficits, only 1 (2.3%; a sensorimotor hemisyndrome) was related to the technique of operculoinsular cortectomy (injury to a middle cerebral artery branch), while the other 2 (arm hypoesthesia and hemianopia) were attributed to cortical resection beyond the operculoinsular area. With multivariate analysis, a postoperative neurological deficit was associated with preoperative insular hypometabolism on PET scan. Postoperative motor deficit (29.6% of procedures) was correlated with fewer years of neurosurgical experience and frontal operculectomies, but not with corona radiata ischemic lesions. Ischemic lesions in the posterior two-thirds of the corona radiata (40.9% of procedures) were associated with parietal operculectomies, but not with posterior insulectomies. Operculoinsular cortectomy for refractory epilepsy is a relatively safe therapeutic option but temporary neurological deficits after surgery are frequent. This study highlights the role of frontal/parietal opercula resections in postoperative complications. Corona radiata ischemic lesions are not clearly related to motor deficits. There were no obvious permanent neurological consequences of losing a part of an epileptic insula, including on the dominant side for language. A low complication rate can be achieved if the following conditions are met: 1) microsurgical technique is applied to spare cortical branches of the middle cerebral artery; 2) the resection of an opercula is done only if the opercula is part of the epileptic focus; and 3) the neurosurgeon involved has proper training and experience.

Cerebral glucose metabolism changes in chronic ischemia patients following subcranial-intracranial bypass.

The use of the internal maxillary artery (IMA) in intracranial artery bypass or subcranial-intracranial (SC-IC) bypass has recently been described as an alternative to traditional bypass. This study explores cerebral glucose metabolism characteristics of SC-IC bypass. Ten crescendo transient ischemic attack (TIA) patients with chronic occlusion of the middle cerebral artery (MCA) received bypass surgery of IMA with the radial artery graft (RAG) to the branch of MCA. The graft's flow volume (FV) was measured by operative intraoperative duplex ultrasonography. Positron emission tomography (PET)/computed tomography (CT) was used to calculate the preoperational and postoperational average of the standard uptake value (SUVavg) of the 18-fluoro-2-deoxy-D-glucose (18F-FDG) in the region of interest (ROI). The asymmetric index (AI) is recommended to reflect the SUVavg changes, and subsequently, cerebral glucose metabolism changes are supposedly clarified. Patent IMA-RAG-MCA bypass in ten chronic ischemia patients was confirmed by angiography after surgery. The intraoperative FV measurement value was 65.64 ± 10.52 (58.11-73.17) ml/min. Before the operation, the SUVavg of the ROI in the ischemic hemisphere (4.76 ± 2.35 (3.08-6.04)) clearly decreased compared to the one (5.99 ± 2.63 (4.11-7.87)) in the contralateral mirror region (P = 0.003). The result of AI of preoperation minus AI of postoperation was more than 10% (P = 0.031), which indicated suspicious significant changes in cerebral metabolism. All symptoms of study patients having crescendo ischemia were resolved in 1month after the operation. In the cerebral hypoperfusion territory, uptake of 18F-FDG deceased. Improving the flow volume via SC-IC bypass makes available an elevated uptake of 18F-FDG.

Neuroangiography patterns of the middle cerebral artery: Study of 554 cerebral angiography results

The middle cerebral artery (MCA) is the largest and most complex of cerebral arteries because the cerebral neocortex is significantly developed in humans [1,2]. The MCA covers a large part of the cerebral hemispheres; therefore, it is exposed during surgical intervention in that area. Aspects of the cerebral branches tend to vary, and different branching patterns can be described. In the past, surgical interest in the MCA has been directed at avoiding damage to its branches during surgery performed within its territory. Microsurgical techniques have made reconstruction and bypass to the MCA, surgical approaches to MCA aneurysms and resection of arteriovenous malformations (AVMs) related to MCA branches common procedures in vascular neurosurgery. The vascular territory of the MCA includes some of the most eloquent cortical areas for motor and sensory functions. That territory encompasses the receptive and expressive components of language, abstract thought and other faculties of higher cognitive functioning. Moreover, the perforating branches of the proximal MCA supply the basal ganglia and important descending and corticospinal tracts. Anatomical variations of the MCA have to be recognised when planning interventions in order to avoid damage or occlusion of the perforating vessels that arise from the MCA and to assess their contribution to the perfusion of the deep MCA territory. Descriptions of the origins and possible common trunks of the MCA branches are still lacking in the literature. While bifurcation and trifurcation types of MCA branching are usually described, most studies fail to mention the different subtypes. Moreover, there is still some confusion about the criteria used to determine the different branching subtypes. Thus, the present study aimed to review the neuroangiography patterns of the MCA.

Mechanical Thrombectomy in Distal Vessels: Revascularization Rates, Complications, and Functional Outcome

Pivotal trials have shown the tremendous efficacy of mechanical thrombectomy in proximal occlusions. However distal occlusions involving second-order branches of the middle cerebral artery and beyond, anterior cerebral and posterior cerebral arteries were not represented. In this study, we investigated the feasibility and safety of distal circulation mechanical thrombectomy. A retrospective review of patients presenting with distal circulation acute ischemic stroke who underwent mechanical thrombectomy 2010 and2018. Of 453 patients who underwent mechanical thrombectomy for acute ischemic stroke, 76 had a distal occlusion. The mean National Institute Health Stroke Scale on admission was 12. Vessels involved included second-order branches of the middle cerebral artery (89%), third- and fourth-order branches of the middle cerebral artery (5%), second-order branch of the anterior cerebral artery (3%), and posterior cerebral artery (3%). Most procedures required 1 pass to recanalize the vessel (55%, n= 42). Thrombolysis in Cerebral Infarction score ≥IIb was achieved in 89% of subjects. Mortality rate was 8% and independent functional outcome of m Rankin score ≤2 at 3 months was seen in 64.7% with clinical follow-up. On multivariate analysis, distal circulation had a significantly shorter length of stay by about 2 days, compared with proximal circulation. Subjects with proximal occlusion were more than 5 times more likely to have a good Thrombolysis in Cerebral Infarction score compared with the distal group. There was no significant difference in periprocedural and postprocedural complications, good functional outcome at 3 months, and mortality between both groups. Mechanical thrombectomy procedure for distal circulation strokes is as effective and safe as a proximal group. Though distal vessels supply smaller brain area; however, when symptoms are pronounced, the benefit of the procedure outweighs the risks.

Orphaned Middle Cerebral Artery Side-to-Side In Situ Bypass as a Favorable Alternative Approach for Complex Middle Cerebral Artery Aneurysm Treatment: A Case Series

Middle cerebral artery (MCA) aneurysms have continued to be primarily managed microsurgically. In cases of complex MCA aneurysms, revascularization could facilitate effective aneurysm treatment. The MCA candelabra provides excellent candidates for in situ side-to-side bypass. In the present case series, we have described applications of MCA in situ side-to-side bypass for the management of complex MCA aneurysms, along with a review of the pertinent data. A retrospective review of a prospectively maintained neurosurgical patient database was performed to identify all patients treated with MCA side-to-side in situ bypass. Six consecutive patients were identified and included in the present series, representing a single-surgeon experience from February 2016 to November2018. Of the 6 complex MCA aneurysms, all were unruptured, and one half had been treated via a minipterional approach that also allowed for simultaneous anterior communicating artery aneurysm clipping in 1 case. The median temporary occlusion time for anastomosis was 33 minutes (interquartile range [IQR], 30.3-35 minutes). Bypass patency was confirmed in all cases both intraoperatively and postoperatively. The median hospitalization time was 4.5 days (IQR, 2-8 days). The median follow-up period was 5.5 months (IQR, 2.8-22.3 months). All patients had achieved excellent or good (≤1) modified Rankin scale scores at discharge and during the follow-up period. No mortalities occurred, and no technical, bypass-related, or ischemic morbidities had developed. Our experience with MCA side-to-side in situ bypass has demonstrated its safety and utility in complex MCA aneurysm management. The favorable anatomy of the MCA branches allows for minimally invasive revascularization and clipping that can potentially reduce the hospitalization time and incidence of perioperative morbidity.

Brain Bypass Surgery for Complex Middle Cerebral Artery Aneurysms: Evolving Techniques, Results, and Lessons Learned

To analyze a consecutive series of patients with middle cerebral artery (MCA) aneurysms who needed an adjunctive cerebral revascularization procedure to achieve aneurysm occlusion with preservation of flow through all MCA branches. A total of 42 patients with 43 MCA aneurysms underwent 52 bypass procedures over 13 years. The location of the aneurysm were M1 trunk, M1 bifurcation, M2 and beyond. The bypasses performed included intracranial bypasses (resection with end to end anastomosis, end to side implantation, side to side anastomosis, and short interposition graft), extraintracranial bypasses (superficial temporal to middle cerebral artery anastomosis, and radial artery bypass graft, or saphenous vein graft), double bypasses, Y-grafts, and combined techniques. Forty-two of 43 aneurysms (98%) had patent bypasses at long-term follow-up. All 43 aneurysms were completely occluded at last follow-up. Six patients (14%) developed strokes related to the surgical treatment. At last follow-up, 36 patients had a modified Rankin score of 0-2, 5 patients had modified Rankin score 3-5, and 1 died. In this series, 31 (73.8%) patients improved, 8 (19%) patients had same functional status, and 3 (7.2%) patients deteriorated, including 1 patient who expired due to sepsis. The mean clinical follow-up duration was 39.3 months (0.4-124 months) and the mean radiological follow-up was 37 months (0.4-134 months). Cerebral revascularization is an important adjunct for treating MCA aneurysms and can be done safely. The article provides the insights we gained by rising through the learning curve.

In Reply to the Letter to the Editor Regarding “Gelatin Paste as an Alternative Cost-Effective Hemostatic Agent in Cranial Surgery: Doing More with Less”

Perioperative cerebral infarction is a potential complication of glioma resection, of which insular tumors are at higher risk because of the proximity of middle cerebral artery branches, including the lateral lenticulostriates and long insular arteries. In this study, 3 patients received three-dimensional rotational angiography, which was fused with magnetic resonance imaging (MRI) for frameless stereotactic navigation during dominant-hemisphere insular glioma resection.All patients obtained a preoperative catheter angiogram with a three-dimensional rotational acquisition of the ipsilateral internal carotid artery. The pixel-based axial three-dimensional angiography data, thin-cut structural MRI, tractography from diffusion tensor imaging, and expressive language activation from functional MRI were uploaded into the iPlan software (Brainlab, Heimstetten, Germany) and fused. The target tumor, regional blood vessels, adjacent functional areas, and their associated fiber tracts were segmented and overlaid on the appropriate MRI sequence. This image fusion was used preoperatively to visualize the relationship of the mass with the adjacent vasculature and intraoperatively for frameless stereotactic navigation to optimize preservation of arterial structures.Three patients aged 27–60 years with excellent baseline functional status presented with seizures and were found to have a large dominant-hemisphere T2 hyperintense nonenhancing insular mass. Surgical resection was performed using multimodality neuronavigation. None sustained a postoperative arterial infarction or a perioperative neurologic deficit.Neuronavigation using a fusion of three-dimensional rotational angiography with MRI is a technique that can be used for preoperative planning and during resection of insular gliomas to optimize preservation of adjacent arteries.

Real-time neuropsychological testing during endovascular occlusion of a fusiform aneurysm in the left middle cerebral artery

Abstract Real-time neuropsychological testing (RTNT) was used to test whether permanent endovascular occlusion of the insular branch of the left middle cerebral artery (MCA) helped avoid cognitive and neurological complications following the procedure. This patient suffered from a fusiform aneurysm along the insular branch of the MCA in the territory supplied in the left inferior frontal gyrus, around Broca's area. Pre-intervention neuropsychological testing was normal. During temporary occlusion lasting 25 min, the patient continuously performed at ceiling on the RTNT neuropsychological and language tasks. Thus, permanent occlusion followed. In addition, fMRI was used to investigate changes induced by the procedure. In the language domain, rearrangements in activation in Broca's area and in the left insula were detected by silent and overt production tasks. In the motor domain, decreased activation in the sensorimotor cortex during right-hand movement control was reported along with decreased right-hand sensibility. Post-intervention neuropsychological testing was normal. Results showed that RTNT can be used reliably during temporary occlusion in the specific case of a quite small branch of the MCA to provide continuous feedback on the patient's cognitive and language status and is predictive of post-intervention functioning. In addition, the study enabled us to detect changes in functional organization triggered by temporary occlusion of a branch of the left middle cerebral artery.

A Novel Na + -K + -Cl − Cotransporter 1 Inhibitor STS66* Reduces Brain Damage in Mice After Ischemic Stroke

Background and Purpose- Inhibition of brain NKCC1 (Na+-K+-Cl- cotransporter 1) with bumetanide (BMT) is of interest in ischemic stroke therapy. However, its poor brain penetration limits the application. In this study, we investigated the efficacy of 2 novel NKCC1 inhibitors, a lipophilic BMT prodrug STS5 (2-(Dimethylamino)ethyl 3-(butylamino)-4-phenoxy-5-sulfamoyl-benzoate;hydrochloride) and a novel NKCC1 inhibitor STS66 (3-(Butylamino)-2-phenoxy-5-[(2,2,2-trifluoroethylamino)methyl]benzenesulfonamide), on reducing ischemic brain injury. Methods- Large-vessel transient ischemic stroke in normotensive C57BL/6J mice was induced with 50-min occlusion of the middle cerebral artery and reperfusion. Focal, permanent ischemic stroke in angiotensin II (Ang II)-induced hypertensive C57BL/6J mice was induced by permanent occlusion of distal branches of middle cerebral artery. A total of 206 mice were randomly assigned to receive vehicle DMSO, BMT, STS5, or STS66. Results- Poststroke BMT, STS5, or STS66 treatment significantly decreased infarct volume and cerebral swelling by ≈40% to 50% in normotensive mice after transient middle cerebral artery occlusion, but STS66-treated mice displayed better survival and sensorimotor functional recovery. STS5 treatment increased the mortality. Ang II-induced hypertensive mice exhibited increased phosphorylatory activation of SPAK (Ste20-related proline alanine-rich kinase) and NKCC1, as well as worsened infarct and neurological deficit after permanent distal middle cerebral artery occlusion. Conclusions- The novel NKCC1 inhibitor STS66 is superior to BMT and STS5 in reducing ischemic infarction, swelling, and neurological deficits in large-vessel transient ischemic stroke, as well as in permanent focal ischemic stroke with hypertension comorbidity.

Frameless Stereotactic Navigation during Insular Glioma Resection using Fusion of Three-Dimensional Rotational Angiography and Magnetic Resonance Imaging

Perioperative cerebral infarction is a potential complication of glioma resection, of which insular tumors are at higher risk because of the proximity of middle cerebral artery branches, including the lateral lenticulostriates and long insular arteries. In this study, 3 patients received three-dimensional rotational angiography, which was fused with magnetic resonance imaging (MRI) for frameless stereotactic navigation during dominant-hemisphere insular glioma resection. All patients obtained a preoperative catheter angiogram with a three-dimensional rotational acquisition of the ipsilateral internal carotid artery. The pixel-based axial three-dimensional angiography data, thin-cut structural MRI, tractography from diffusion tensor imaging, and expressive language activation from functional MRI were uploaded into the iPlan software (Brainlab, Heimstetten, Germany) and fused. The target tumor, regional blood vessels, adjacent functional areas, and their associated fiber tracts were segmented and overlaid on the appropriate MRI sequence. This image fusion was used preoperatively to visualize the relationship of the mass with the adjacent vasculature and intraoperatively for frameless stereotactic navigation to optimize preservation of arterial structures. Three patients aged 27-60 years with excellent baseline functional status presented with seizures and were found to have a large dominant-hemisphere T2 hyperintense nonenhancing insular mass. Surgical resection was performed using multimodality neuronavigation. None sustained a postoperative arterial infarction or a perioperative neurologic deficit. Neuronavigation using a fusion of three-dimensional rotational angiography with MRI is a technique that can be used for preoperative planning and during resection of insular gliomas to optimize preservation of adjacent arteries.

The Artery of Aphasia, A Uniquely Sensitive Posterior Temporal Middle Cerebral Artery Branch that Supplies Language Areas in the Brain: Anatomy and Report of Four Cases

Arterial disruption during brain surgery can cause devastating injuries to wide expanses of white and gray matter beyond the tumor resection cavity. Such damage may occur as a result of disrupting blood flow through en passage arteries. Identification of these arteries is critical to prevent unforeseen neurologic sequelae during brain tumor resection. In this study, we discuss one such artery, termed the artery of aphasia (AoA), which when disrupted can lead to receptive and expressive language deficits. We performed a retrospective review of all patients undergoing an awake craniotomy for resection of a glioma by the senior author from 2012 to 2018. Patients were included if they experienced language deficits secondary to postoperative infarction in the left posterior temporal lobe in the distribution of the AoA. The gross anatomy of the AoA was then compared with activation likelihood estimations of the auditory and semantic language networks using coordinate-based meta-analytic techniques. We identified 4 patients with left-sided posterior temporal artery infarctions in the distribution of the AoA on diffusion-weighted magnetic resonance imaging. All 4 patients developed substantial expressive and receptive language deficits after surgery. Functional language improvement occurred in only 2/4 patients. Activation likelihood estimations localized parts of the auditory and semantic language networks in the distribution of the AoA. The AoA is prone to blood flow disruption despite benign manipulation. Patients seem to have limited capacity for speech recovery after intraoperative ischemia in the distribution of this artery, which supplies parts of the auditory and semantic language networks.

Assessment of collateral blood flow in patients with distal branch occlusion of the middle cerebral artery

PurposeAim of this study was to evaluate the collateral blood flow between more distal branches of the middle cerebral artery (MCA) in the case of peripheral MCA branch occlusion on dynamic 4D angiograms. We sought to individually predict the finally resulting infarction volume with regard to the extent of collateral blood flow. MethodsOverall, 35 acute ischemic stroke patients with peripheral MCA branch occlusion were included. Volumes of the ischemic infarctions and perfusion deficits were measured on diffusion-weighted images DWI and time-to-peak TTP (> 4 s). Collateral flow on 4D MR angiograms were classified as previously specified. ResultsOn DWI, the ischemic lesions had a mean volume of 3.4 ± 15.1 mL while the mean volume on TTP (> 4 s) was significantly larger 22.0 ± 18.1 mL (P < 0.001). On dynamic 4D angiograms we observed grade 1 in 8 (22.9%), grade 2 in 4 (11.4%), grade 3 in 10 (28.6%), and grade 4 in 13 (37.1%) patients. In comparison to patients with better collateralization (grade 3–4) patients with less sufficient collateralization (grade 0–2) demonstrated larger infarction volumes on initial (11.1 mL (IQR 2.9–35.5) vs. 2.1 mL (IQR 0.5–4.5), P = 0.03) and follow-up DWI (15.5 mL (IQR 12.6–23.3) vs. 1.9 mL (IQR 0.5–4.5), P = 0.03) with prominent infarction growth (7.4 mL (IQR 2.6–10.1) vs. 0.9 mL (IQR 0.2–2.6), P = 0.08). ConclusionsIn the majority of cases with distal MCA branch occlusion a good collateral blood flow has been observed. Nevertheless, in approximately one quarter of patients an insufficient collateral blood flow has been detected that was associated with substantial infarction growth.

Optogenetic interrogation of neurovascular coupling in the cerebral cortex of transgenic mice

Objective. We introduce an engineering approach to study spatiotemporal correlations between vasodynamics and the nearby neural activity in open-loop and closed-loop paradigms. Approach. We integrated optogenetic technology with optical coherence tomography to apply spatiotemporal patterns of optical neurostimulation to the cortex of transgenic optogenetic mice and measure blood flow-rate, velocity, and diameter changes of selected middle cerebral artery branches. Main results. The spatiotemporal characteristics of blood flow-rate, velocity, and vessel diameter responses to localized neurostimulation light pulses were measured. It was observed that the location of stimulation relative to the surrounding vascular topology had notable effects on temporal patterns of vasodynamic responses. This effect was studied by creating velocity, flow-rate, and diameter sensitivity maps for selected arteries. Generally, neural stimulation in the vicinity of downstream capillaries of an artery evoked a fast transient increase in the blood flow-rate, velocity, and vessel diameter which was followed by a long-lasting secondary peak-response. The temporal span of the flow-rate response was quasi-linearly proportional to the length of stimulation. When neural stimulation was delivered to the area in the vicinity of one daughter branch of an artery, in other branches, we observed some drop in blood velocity and/or flow-rate and concurring increase of the vessel diameter. To examine the reliability of the coupling between neural activity and regional blood flow, a closed-loop feedback controller was implemented which is capable of maintaining blood flow-rate at any desired level for relatively longer periods by continuously adjusting the width of stimulation pulses. Significance. The proposed approach opens new lines of research with potential applications in understanding the role of different cell types in the cerebrovascular regulatory mechanisms and the study of the adaptive process of angiogenesis in the cerebral cortex. The observation of incoherent responses of vessel diameter, blood flow-rate, and velocity suggests that such detailed information is necessary to obtain an accurate interpretation of the data acquired via hemodynamic based functional imaging techniques.