Outcome after acute ischemic stroke is linked to sex-specific lesion patterns.

Acute ischemic stroke affects men and women differently. In particular, women are often reported to experience higher acute stroke severity than men. We derived a low-dimensional representation of anatomical stroke lesions and designed a Bayesian hierarchical modeling framework tailored to estimate possible sex differences in lesion patterns linked to acute stroke severity (National Institute of Health Stroke Scale). This framework was developed in 555 patients (38% female). Findings were validated in an independent cohort (n = 503, 41% female). Here, we show brain lesions in regions subserving motor and language functions help explain stroke severity in both men and women, however more widespread lesion patterns are relevant in female patients. Higher stroke severity in women, but not men, is associated with left hemisphere lesions in the vicinity of the posterior circulation. Our results suggest there are sex-specific functional cerebral asymmetries that may be important for future investigations of sex-stratified approaches to management of acute ischemic stroke.

Mechanical Revascularization in the Era of the Field Assessment Stroke Triage for Emergency Destination (FAST-ED): A Retrospective Cohort Assessment in a Community Stroke Practice.

BACKGROUND: Endovascular mechanical revascularization has become the mainstay acute stroke management secondary to emergent large vessel occlusions. In patients who can benefit from mechanical revascularization, the ability to intervene in a timely manner directly correlates with improved outcomes. The field assessment for stroke triage (FAST-ED) prehospital triage tool, is one of many stroke severity scales designed to decrease time to diagnosis in the field and optimize patient triage to comprehensive stroke centers. It is however unclear what impact if any, this tool has on time to activation of hospital stroke intervention teams. We set out to assess the impact of the implementation of the FAST-ED triage tool on the activation of the stroke intervention team in a community stroke treatment practice. METHODS: We retrospectively reviewed institutional records for consecutive admissions with reported stroke alerts between March 2017 and September 2018, and selected patients who presented via Emergency Medical Services (EMS). The association between FAST-ED scores and impact on time to revascularization as well as the association between FAST-ED scores and the presence of emergent large vessel occlusion were analyzed. RESULTS: There was a statistically significant improvement in interventional team activation times in favor of the FAST-ED cohort, (P < .05). CONCLUSIONS: FAST-ED implementation demonstrates a statistically significant improvement on stroke team activation times for patients who are candidates for mechanical revascularization. Larger cohort analysis is needed to fully evaluate the magnitude of this effect.

STA-MCA Bypass Under Local Anesthesia.

BACKGROUND AND AIMS: The superficial temporal artery to middle cerebral artery (STA-MCA) bypass procedure has continually evolved and new strategies have been advocated to reduce anesthetic or surgical mortality and morbidity. Further simplifying and decreasing the invasiveness of STA-MCA bypass by performing this operation without endotracheal general anesthesia was deemed feasible in certain subsets of patients. METHODS: We performed STA-MCA bypass using local anesthesia using a sedative in 45 patients with hemodynamically compromised cerebrovascular occlusive disease as well as multiple comorbidities in the period between February 2010 and April 2016. The technique is based on preoperative identification of the point at which the donor and recipient vessels are in closest proximity. The preoperative use of computed tomography angiography allowed us to identify the target point precisely and use a minimally invasive procedure. All patients received dexmedetomidine as the sole sedative agent, together with scalp block local anesthesia with an unsecured airway. RESULTS: Successful STA-MCA bypass surgeries were achieved via a preselected minimally invasive approach in all cases. There was good hemodynamic stability throughout surgery. No airway/ventilation complications occurred and no patient was converted to general anesthesia. The patients subjectively tolerated this technique well with a high rate of satisfaction. Postoperative magnetic resonance angiography confirmed patent bypass in 44 of 45 patients (patency rate of 97.8%). There were two postoperative hyper-perfusion syndromes and one cerebral ischemia with transient neurological symptoms (postoperative complication rate of 6.3%). No recurrence of ipsilateral cerebral ischemia was observed during the follow-up periods. There was one contralateral cardiogenic cerebral embolism during the follow-up period. The overall stroke rate was calculated as 1%/patient/year. CONCLUSIONS: Our initial experience confirms the feasibility of performing STA-MCA bypass under local anesthesia without endotracheal general anesthesia.

Advances and innovations in revascularization of extracranial vertebral artery.

Revascularization of the extracranial vertebral artery has evolved significantly since the adoption of endovascular techniques. The current neurosurgical armamentarium includes microsurgical and endovascular approaches. The indications for each treatment modality, however, still need to be further delineated. In contrast to carotid artery endarterectomy and carotid artery angioplasty/stenting, there is limited comparative evidence on the efficacy of medical, open, and endovascular treatment of atherosclerotic disease of the extracranial vertebral artery. More recently, drug-eluting stents have gained momentum after high rates of in-stent restenosis have been reported with bare metal stents placed in the vertebral artery. In this article, we discuss the indications, clinical assessment, and surgical nuances of microsurgical and endovascular revascularization for atherosclerotic disease of the extracranial vertebral artery. Despite a general tendency to consider endovascular treatment in the majority of patients, ultimately, open and endovascular revascularization of extracranial vertebral artery should be regarded as complementary therapies and both treatment options need to be discussed in selected patients.

Superficial temporal artery-middle cerebral artery bypass using local anesthesia and a sedative without endotracheal general anesthesia.

OBJECT: Superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses have continually evolved, and new strategies have been advocated for reducing anesthetic or surgical morbidity and mortality. Further simplifying, and decreasing the invasiveness of, STA-MCA bypass by performing this operation without endotracheal general anesthesia was believed to be feasible in certain subsets of patients. METHODS: The authors performed STA-MCA bypass using local anesthesia with a sedative in 10 patients with hemodynamically compromised occlusive cerebrovascular disease, as well as multiple comorbidities, between February 2010 and September 2011. The technique is based on the preoperative identification of the point at which the donor and recipient vessels are in closest proximity. Preoperative use of CT angiography allowed the authors to identify the target point precisely and use a minimally invasive procedure. All patients received dexmedetomidine as the sole sedative agent, together with scalp-blocking local anesthesia, with an unsecured airway. RESULTS: Successful STA-MCA bypass surgeries were achieved via a preselected minimally invasive approach in all cases. There was good hemodynamic stability throughout surgery. No airway or ventilation complications occurred, and no patients were converted to general anesthesia. Subjectively, patients tolerated the technique well with a high rate of satisfaction. There were no perioperative morbidities or deaths. Postoperative MR angiography confirmed a patent bypass in all patients. All patients remained symptom free and returned to normal daily life following the operation. CONCLUSIONS: This initial experience confirms the feasibility of performing STA-MCA bypass without endotracheal general anesthesia. This novel technique produced a high degree of patient satisfaction.

Dissection of the posterior inferior cerebellar artery in a young adult with cerebellar infarct.

The posterior inferior cerebellar artery (PICA) is frequently involved in dissection of the vertebral artery (VA); however, isolated PICA dissection has rarely been reported. A 37-year-old man experienced acute and progressive drowsiness, vertigo, occipital headache, vomiting, and ataxia. There was no precedent trauma or chiropractic manipulation. Neurologically, he had dysmetria of the left extremities. His NIHSS score was 3. Brain magnetic resonance imaging showed an acute cerebellar infarct in the left PICA territory. Magnetic resonance angiography showed a faint signal adjacent to the junction of the left VA and PICA, suggesting a vascular shadow. Catheter angiography showed focal stenosis with a post-stenotic fusiform aneurysmal dilatation of the left proximal PICA that was highly suggestive of dissection with pseudoaneurysm formation. He was treated with clopidogrel and was free of neurological symptoms 3 months after the stroke event. Isolated PICA dissection may be considered in patients with PICA territory infarct or subarachnoid hemorrhage. Treatment depends on the manifestations; ruptured dissecting aneurysms are often treated with surgery or embolization, and infarcts are usually treated with antithrombotic agents.

Gene expression in cerebral ischemia: a new approach for neuroprotection.

Cerebral ischemia is one of the strongest stimuli for gene induction in the brain. Hundreds of genes have been found to be induced by brain ischemia. Many genes are involved in neurodestructive functions such as excitotoxicity, inflammatory response and neuronal apoptosis. However, cerebral ischemia is also a powerful reformatting and reprogramming stimulus for the brain through neuroprotective gene expression. Several genes may participate in both cellular responses. Thus, isolation of candidate genes for neuroprotection strategies and interpretation of expression changes have been proven difficult. Nevertheless, many studies are being carried out to improve the knowledge of the gene activation and protein expression following ischemic stroke, as well as in the development of new therapies that modify biochemical, molecular and genetic changes underlying cerebral ischemia. Owing to the complexity of the process involving numerous critical genes expressed differentially in time, space and concentration, ongoing therapeutic efforts should be based on multiple interventions at different levels. By modification of the acute gene expression induced by ischemia or the apoptotic gene program, gene therapy is a promising treatment but is still in a very experimental phase. Some hurdles will have to be overcome before these therapies can be introduced into human clinical stroke trials.

Electromagnetic therapeutic angiogenesis: the next step.

Therapeutic angiogenesis, in the form of growth factor protein administration or gene therapy, is a new method of treatment for patients with severe coronary and peripheral artery disease not amenable to conventional methods of revascularization. Furthermore, a new experimental strategy increases endogenous angiogenesis in ischemic tissue to induce local 'angiogens' by means of electromagnetic stimulation. Further studies examining the molecular basis and clinical efficacy of electromagnetic angiogenesis are necessary.