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Background and Purpose: Quantitative electroencephalogram (QEEG) parameters have been previously utilized in prognosis following acute ischemic stroke (AIS). However, the use and interpretation of QEEG parameters remain scarce following endovascular treatment (EVT) of AIS. Methods: AIS patients were prospectively enrolled following EVT, and 24-hour EEG monitoring was conducted. Global delta/alpha ratio (DAR), (delta + theta)/(alpha + beta) ratio (DTABR), and relative band power were analyzed. Primary outcome was a poor outcome (modified Rankin Scale ≥4 at 90-day follow-up). Multivariate logistic regression and diagnostic analyses were performed. Results: Poor outcome was seen in 35.5% (11/31) of enrolled patients. Multivariable logistic regression identified that higher DAR (OR 1.10, 95% CI 1.02–1.18, p = 0.02) and higher DTABR (OR 1.13, 95% CI 1.01–1.27, p = 0.02) were associated with poor outcome. DAR ≥14.3 demonstrated high sensitivity (90.9%), specificity (90.0%) and accuracy (90.3%) for poor outcome. Conclusions: Early evidence of elevated DAR and DTABR on quantitative EEG was associated with poor outcome at 90 days following EVT for AIS. [ABSTRACT FROM AUTHOR]

Intravenous thrombolysis elevates the prognostic level of acute ischemic stroke (AIS) patients. Normobaric hyperoxia (NBO) delays the progression of the infarct core and promotes neurological recovery. However, it is uncertain whether NBO can further raise the prognostic level of AIS patients based on intravenous thrombolysis. To explore the efficacy and safety of NBO combined with intravenous thrombolysis on AIS patients. This observational study included anterior circulation stroke patients who received intravenous thrombolysis within 4.5 h after stroke onset. These patients were divided into two groups based on whether or not they received NBO therapy. The baseline data and the prognosis of the two groups were compared. The primary outcome was the proportion of functional independence (modified Rankin Scale 0–2) at 90 days post discharge. A total of 227 patients were included in this study. 125 patients received NBO therapy combined with intravenous thrombolysis, while 102 patients received intravenous thrombolysis only. Overall, the rate of recanalization was 83.3%. Consequently, 101 patients (80.8%) who received NBO combined with intravenous thrombolysis and 63 patients (61.8%) in the control group achieved functional independence (P = 0.002). Multivariable logistic regression analysis showed that NBO combined with intravenous thrombolysis over intravenous thrombolysis alone was associated with 90-day functional independence (OR: 2.318; 95% CI: 1.226–4.381; P = 0.01). This study verified the efficacy and safety of NBO combined with intravenous thrombolysis in AIS patients. Prospective study is needed to further substantiate these findings. [ABSTRACT FROM AUTHOR]

Objectives:Fractional flow reserve (FFR) accurately predicts the degree of stenosis and is now widely used to identify clinically significant severe coronary artery lesions. In the current study, we utilized a similar indicator, fractional flow (FF), to determine the hemodynamic impact of symptomatic intracranial atherosclerotic stenosis (ICAS) and to assess the correlation of FF with the severity of stenosis and collateral circulation. Methods:Patients with symptomatic ICAS (70–99% stenosis) confirmed on digital subtraction angiography (DSA) were consecutively recruited. FF was obtained during DSA examination with the use of pressure sensors and was measured as a ratio, comparing measurements distal to an ICAS lesion (Pd) and within the aorta (Pa). The degree of leptomeningeal collateralization was graded from zero (absent) to four (complete compensatory). The correlation between FF, anatomical stenosis, and collateral status was then analyzed. Results:Twenty-five patients with a mean age of 55.6 years were analyzed. The median percentage of stenosis and median FF were 82.3 and 0.68%, respectively. Eleven patients were found to have poor collateralization (grade 0-2), and fourteen patients were identified with good collateral circulation (grade 3-4). Overall, the hemodynamic impact of an atherosclerotic lesions worsened (decreased FF) as the percentage of stenosis increased, although this did not reach statistical significance (r = −0.398,p = 0.06). However, the status of collateralization significantly altered this correlation, worsening the hemodynamic impact in patients with poor collateral circulation (r = −0.677,p = 0.032). There was no difference in patients with good collateral circulation (r = −0.279,p = 0.356). Conclusion:An anatomically severe (70–99%) symptomatic ICAS lesion may generate significant hemodynamic stress downstream as assessed by the indicator FF, particularly in patients with poor collateral circulation. Further, good collateralization may mitigate this hemodynamic impact, partially explaining the protective effect of collateral circulation against recurrent stroke in such patients. [ABSTRACT FROM PUBLISHER]

In this review, we briefly introduce recent developments and updates in neurocritical care in the treatment of stroke, including both ischemic and hemorrhagic stroke. Time to recanalization remains the major rate limiting step in the treatment of acute ischemic stroke as only a minority of patients arrive within a timeframe appropriate for treatment. Whether caring for a patient following ischemic or hemorrhagic stroke, the principle focus of neurocritical care for acute brain catastrophes is the identification and prevention of secondary brain injury. While much advancement is still needed for optimum care of patients suffering from ischemic or hemorrhagic stroke, the field continues to evolve in ways that promote improved patient outcomes. [ABSTRACT FROM AUTHOR]

Background and Objective: Hypothermia has shown promise as a neuroprotective strategy for stroke. The use of whole body hypothermia has limited clinical utility due to many severe side effects. Selective brain cooling, or local brain hypothermia, has been previously proposed as an alternative treatment strategy. This study investigated the safety, feasibility, and efficacy of selective brain hypothermia induced by local infusion of ice-cold lactated Ringer's solution in rhesus monkeys. Methods: Eight male rhesus monkeys were used in this study. Brain temperature in the territory supplied by middle cerebral artery (MCA) was reduced by infusing 100 mL of ice-cold (0 °C) lactated Ringer's solution over 20 min via a micro-catheter placed in the proximal MCA (n = 4). Vital signs and the temperature of the brain and rectum were monitored before and after infusion. Transcranial Doppler, Magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) were used to evaluate cerebral blood flow, cerebrovascular reactivity (CVR), cerebral edema, and vasospasm. Another cohort of rhesus monkeys (n = 4) were used as systemic cooling controls. Results: Oxygen saturation, blood pressure, heart rate, and hematologic analysis of the two groups remained within the normal range after infusion. Mild cerebral hypothermia (<35 °C) was achieved in 10 min (0.3 °C/min) and was maintained for 20 min in local cortex and striatum following local infusion. The average lowest cerebral temperature in the locally cooled animals was 33.9 ± 0.3 °C in the striatum following 20-min infusion. This was not observed in animals cooled by systemic infusion. The decreases in the rectal temperature for local and systemic infusion were 0.5 ± 0.2 °C and 0.5 ± 0.3 °C, respectively. Selective brain cooling did not cause any cerebral edema as determined by MRI or vasospasm in the perfused vessel based on DSA. Selective cerebral hypothermia did not significantly alter CVR. Conclusion: Local infusion of ice-cold lactated Ringer's solution via micro-catheter is a safe and effective method for selective cerebral hypothermia. This cooling method could potentially be developed as a new treatment in acute ischemic stroke. [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI) induces brain edema via water and glycerol transport channels, called aquaporins (AQPs). The passage of glycerol across brain cellular compartments has been shown during edema. Using a modified impact/head acceleration rodent model of diffuse TBI, we assessed the role of hypoxia inducible factor (HIF)-1alpha in regulating AQP9 expression and glycerol accumulation during the edema formation. Adult (400-425 g) male Sprague-Dawley rats received a closed head injury with a weight drop (450 g, 2-m height) and were allowed to survive up to 48 hours. Some rat groups were administered 2-methoxyestradiol (2ME2, a HIF-1alpha inhibitor) 30 minutes after injury and were euthanized at 4 and 24 hours after injury. Brain edema was measured directly by water content, and glycerol concentration was determined by the Cayman Glycerol Assay. HIF-1alpha and AQP9 protein levels were assessed by Western immunoblotting. This study demonstrated a significant (P<0.05) increase in brain water content at 4-48 hours following impact. Cerebral glycerol was significantly (P<0.05) up-regulated at as early as 1 hour and remained at high levels for up to 48 hours. Similarly, significant (P<0.05) increases in HIF-1alpha and AQP9 protein levels were found at 1 hour and up to 48 hours after injury. Compared to untreated but injured rats, inhibition of HIF-1alpha by 2ME2 significantly (P<0.05) reduced the TBI-induced AQP9 up-regulation. This reduction was temporally associated with significant (P<0.05) decreases in both edema and glycerol accumulation. The data suggested an associated induction of HIF-1alpha, AQP9, and extracellular glycerol accumulation in edema formation following diffuse TBI. The implication of HIF-1alpha and AQP9 underlying TBI-induced edema formation offers possibilities for novel TBI therapies. [ABSTRACT FROM AUTHOR]

Objectives: To determine the protective effects of remote post-conditioning on ischemic brain lesions caused by middle cerebral artery (MCA) occlusion in rats. Methods: A total of 54 animals were used in this present study. An ischemic stroke model was generated by 90-minute occlusion of right MCA (n = 42). Twelve rats were used as control for studying edema and blood-brain barrier (BBB) integrity. Remote post-conditioning was conducted immediately after MCA occlusion in the bilateral lower limb by occluding and releasing the femoral artery for three cycles; each occlusion and release lasted for 10 minutes. After 24 hours of reperfusion, the cerebral infarct volumes were quantified by 2,3,4-triphenytetrazolium-chloride, brain water content was determined by dry/wet weight method, and damage to the BBB was determined by Evans blue extravasation. Results: Remote post-conditioning significantly reduced brain infarct damage (P<0·0001). Brain edema was significantly (P<0·01) reduced after stroke in the remote post-conditioning group. BBB leakage was significantly reduced in the remote post-conditioning group when compared to the control ischemic groups (P<0·05). Conclusion: These results provide evidence that remote post-conditioning, which was initiated after ischemia and before reperfusion, protects against brain injury in experimental ischemic stroke. [ABSTRACT FROM AUTHOR]

Objective: To investigate the characteristics of transcranial Doppler variables in the acute stage of intracerebral hemorrhage (ICH) and its relationship with 14-day death and outcomes at 90 day after onset. Methods: Ninety first-time supratentorial nontraumatic ICH patients were prospectively included. Computed tomography and transcranial Doppler examinations were performed on the first, third, seventh, and fourteenth day after onset. Transcranial Doppler variables were obtained from bilateral middle cerebral arteries. The relationship between ICH outcome and the following variables were analyzed: systolic (Vs), diastolic (Vd), mean (Vm) velocities, and pulsatiliy index (PI) from affected and unaffected hemispheres. Results: Fourteen (15·6%) patients died within 14 days after onset of ICH. The stepwise logistic regression analyses proved presence of intraventricular hemorrhage (OR: 11·91; 95%CI: 1·62-87·42) and PI from unaffected hemisphere (OR: 1·64; 95%CI: 1·19-2·25) to be independent predictors of 14-day death. Forty-eight of the 90 ICH patients performed the transcranial Doppler monitoring at all four time points. Vm from both hemispheres decreased gradually within 14 days after onset. Among the 48 patients, 22 patients were dependent (modified Rankin Scale&ges;3) at 90 days after onset. Compared with patients who were independent at 90 days, Vd (F = 4·98, P = 0·03) and Vm (F = 7·30, P<0·01) from unaffected hemisphere were significantly lower, while the PI was significantly higher in patients who were dependent (F = 9·84, P<0·01). Conclusions: Presence of intraventricular hemorrhage and PI from unaffected hemisphere proved to be independent predictors of 14-day death. Sustained persistent decreases in Vd and Vm and increases in PI from the unaffected hemisphere during the acute stage may be related with dependency at 90 days. [ABSTRACT FROM AUTHOR]

Objectives: Conduction aphasia is usually considered a result of damage of the arcuate fasciculus, which is subjacent to the parietal portion of the supra-marginal gyrus and the upper part of the insula. It is important to stress that many features of conduction aphasia relate to a cortical deficit, more than a pure disconnection mechanism. In this study, we explore the mechanism of Broca-like and Wernicke-like conduction aphasia by using diffusion tensor imaging (DTI) and diffusion tensor imaging-fibre tractograph (DT-FT). Methods: We enrolled five Broca-like conduction aphasia cases, five Wernicke-like aphasia conduction cases and 10 healthy volunteers residing in Beijing and speaking Mandarin. All are right handed. We analyzed the arcuate fasciculus, Broca's areas and Wernicke's areas by DTI and measured fractional anisotrogy (FA). The results of left and right hemispheres were compared in both conduction aphasia cases and volunteers. Then the results of the conduction aphasia cases were compared with those of volunteers. The fibre construction of Broca's and Wernicke's areas was also compared by DTI-FT. Results: The FA occupied by the identified connective pathways (Broca's area, Wernicke's area and the arcuate fasciculus) in the left hemisphere was larger than that in the right hemisphere in the control group (P<0·05). Among Broca-like conduction aphasia cases, the FA of the left Broca's area was smaller than that of the right mirror side (P<0·05), and the FA of the left anterior segment of the arcuate fasciculus was smaller than that of right mirror side (P<0·05). On the other hand, among Wernicke-like conduction aphasia patients, the FA of the left Wernicke's area was smaller than that of right mirror side (P<0·05), and the FA of left posterior segment of arcuate fasciculus was smaller than that of right mirror side (P<0·05). Conclusions: Conduction aphasia results from not only arcuate fasciculus destruction, but also from disruption of the associated cortical areas. Along different segments of the arcuate fasciculus, the characteristics of language disorders of conduction aphasia were different. A lesion involving Broca's area and the anterior segments of the arcuate fasciculus would lead to Broca-like conduction aphasia, whereas a lesion involved Wernicke's area and posterior segments of the arcuate fasciculus would lead to Wernicke-like conduction aphasia. [ABSTRACT FROM AUTHOR]