The risk factors of gastrointestinal bleeding in acute ischaemic stroke

Gastrointestinal (GI) bleeding is one of the most serious complications after an acute ischaemic stroke and may affect stroke outcome. We identified predictors and the eventual outcome of gastrointestinal bleeding during the in-patient period following the commencement of aspirin. This was a study of patients with acute ischaemic stroke admitted to Universiti Kebangsaan Malaysia Hospital from June 2000 to January 2001. A single observer, using predefined diagnostic criteria recorded information on demography, risk factors and GI bleeding that occurred during the inpatient period. One hundred and fifteen patients with acute ischaemic stroke were enrolled in the study. Gastrointestinal bleeding was observed in 6 (5.2%) patients. Using univariate analysis, the independent predictors of gastrointestinal bleeding were age (OR 1.25; 95% CI 1.07 to 1.50), and middle cerebral artery (MCA) territory infarcts (OR 9.47; 95% CI 1.62 to 55.5). Using multivariate analysis, the presence of gastrointestinal bleeding increased mortality (OR 24.97; 95% CI 1.97 to 316.91). Older age, and large MCA infarct predict the development gastrointestinal bleeding. Stroke mortality was independently predicted by gastrointestinal bleeding. Prophylactic treatment in elderly patients with large cerebral infarcts may be an area for further investigation.

Analysis of Thrombi Retrieved From Cerebral Arteries of Patients With Acute Ischemic Stroke

Background and Purpose— Information regarding the histological structure of thromboemboli that cause acute stroke provides insight into pathogenesis and clinical management.

Methods— This report describes the histological analysis of thromboemboli retrieved by endovascular mechanical extraction from the middle cerebral artery (MCA) and intracranial carotid artery (ICA) of 25 patients with acute ischemic stroke.

Results— The large majority (75%) of thromboemboli shared architectural features of random fibrin:platelet deposits interspersed with linear collections of nucleated cells (monocytes and neutrophils) and confined erythrocyte-rich regions. This histology was prevalent with both cardioembolic and atherosclerotic sources of embolism. “Red” clots composed uniquely of erythrocytes were uncommon and observed only with incomplete extractions, and cholesterol crystals were notably absent. The histology of thromboemboli that could not be retrieved from 29 concurrent patients may be different. No thrombus >3 mm wide caused stroke limited to the MCA, and no thrombus >5 mm wide was removed from the ICA. A mycotic embolus was successfully removed in 1 case, and a small atheroma and attached intima were removed without clinical consequence from another.

Conclusions— Thromboemboli retrieved from the MCA or intracranial ICA of patients with acute ischemic stroke have similar histological components, whether derived from cardiac or arterial sources. Embolus size determines ultimate destination, those >5 mm wide likely bypassing the cerebral vessels entirely. The fibrin:platelet pattern that dominates thromboembolic structure provides a foundation for both antiplatelet and anticoagulant treatment strategies in stroke prevention.

Immediate catheter-directed reperfusion for acute stroke occurring during diagnostic cardiac catheterization

Acute stroke is a rare but the most dreaded complication of cardiac catheterization. We report a case about the management of an acute stroke that occurred during a diagnostic cardiac catheterization procedure. Immediate catheter-based intraarterial thrombolysis with adjunctive balloon angioplasty of the left middle cerebral artery was carried out. The patient recovered markedly within the first 2 hr and was discharged without neurological sequelae after 3 days. A clinical pathway for acute stroke management in the catheterization laboratory is discussed.

Doppler ultrasonography versus amniocentesis to predict fetal anemia

BACKGROUND

Pregnancies complicated by Rh alloimmunization have been evaluated with the use of serial invasive amniocentesis to determine bilirubin levels by measuring in the amniotic fluid the change in optical density at a wavelength of 450 nm (DeltaOD450); however, this procedure carries risks. Noninvasive Doppler ultrasonographic measurement of the peak velocity of systolic blood flow in the middle cerebral artery also predicts severe fetal anemia, but this test has not been rigorously evaluated in comparison with amniotic-fluid DeltaOD450.

METHODS

We performed a prospective, international, multicenter study including women with RhD-, Rhc-, RhE-, or Fy(a)-alloimmunized pregnancies with indirect antiglobulin titers of at least 1:64 and antigen-positive fetuses to assess whether Doppler ultrasonographic measurement of the peak systolic velocity of blood flow in the middle cerebral artery was at least as sensitive and accurate as measurement of amniotic-fluid DeltaOD450 for diagnosing severe fetal anemia. The results of the two tests were compared with the incidence of fetal anemia, as determined by measurement of hemoglobin levels in fetal blood.

RESULTS

Of 165 fetuses, 74 had severe anemia. For the detection of severe fetal anemia, Doppler ultrasonography of the middle cerebral artery had a sensitivity of 88 percent (95 percent confidence interval, 78 to 93 percent), a specificity of 82 percent (95 percent confidence interval, 73 to 89 percent), and an accuracy of 85 percent (95 percent confidence interval, 79 to 90 percent). Amniotic-fluid DeltaOD450 had a sensitivity of 76 percent (95 percent confidence interval, 65 to 84 percent), a specificity of 77 percent (95 percent confidence interval, 67 to 84 percent), and an accuracy of 76 percent (95 percent confidence interval, 69 to 82 percent). Doppler ultrasonography was more sensitive, by 12 percentage points (95 percent confidence interval, 0.3 to 24.0), and more accurate, by 9 percentage points (95 percent confidence interval, 1.1 to 15.9), than measurement of amniotic-fluid DeltaOD450.

CONCLUSIONS

Doppler measurement of the peak velocity of systolic blood flow in the middle cerebral artery can safely replace invasive testing in the management of Rh-alloimmunized pregnancies. (ClinicalTrials.gov number, NCT00295516.).

The role of spiral CT for the assessment of the intracranial circulation in suspected brain-death

BACKGROUND AND PURPOSE

The aim of this study was to assess the role of spiral CT for the diagnosis of brain death.

METHODS

Over a 12-month period, 15 patients that fulfilled the clinical criteria of brain death were referred from the intensive care unit to evaluate remaining intracranial blood flow by spiral CT. The clinical diagnosis was confirmed by an apnea test in all cases. Two phases of spiral CT were performed at 20 and 60 seconds after the start of contrast media injection. Qualitative analysis included the evaluation of vessel opacification (arteries and veins) by two radiologists in consensus.

RESULTS

The cortical segments of the middle cerebral artery (MCA) were assessable in all patients, whereas the internal cerebral veins could not be evaluated in five patients due to artifacts or intracranial hemorrhage. Opacification of the major branches of the circle of Willis was observed in seven cases. Unilateral opacification of cortical branches of the MCA occurred in one. We did not observe bilateral enhancement of cortical MCA branches. The internal cerebral veins did not enhance in brain death.

CONCLUSION

The absence of internal cerebral vein opacification and the absence of bilateral enhancement of cortical MCA branches constituted the best criteria of brain death by contrast enhanced spiral CT.

Neuroprotective effect of Acorus calamus against middle cerebral artery occlusion-induced ischaemia in rat

The neuroprotective potential of ethanol:water (1:1) extract of rhizomes of Acorus calamus (AC-002) has been investigated in middle cerebral artery occlusion (MCAO)-induced ischaemia in rats. A significant behavioural impairment in Rota-Rod performance and grid walking was observed in rats, 72 hours after MCAO as compared to sham-operated animals. These rats also exhibited an increase in lipid peroxidation (cortex -157%, corpus striatum - 58%) and a decrease in glutathione levels (cortex - 59%, corpus striatum - 34%) and superoxide dismutase (SOD) activity (cortex - 64%, corpus striatum - 32%) as compared to sham-operated animals. Ischaemic rats treated with AC-002 (25 mg/kg, p.o.) exhibited a significant improvement in neurobehavioural performance viz. Rota-Rod performance and grid walking as compared to the MCAO group. Interestingly, treatment with AC-002 in MCAO rats significantly decreased malonaldialdehyde levels in cortex as compared to ischaemic rats. A significant increase in reduced glutathione levels and SOD activity was also observed both in cortex and corpus striatum in MCAO rats treated with AC-002 in comparison to MCAO rats. Treatment with AC-002 in MCAO rats also reduced the contralateral cortical infarct area (19%) as compared to MCAO rats (33%). Neurological function score was improved in the AC-002-treated rats as compared to the MCAO group. The results of the present study indicate the neuroprotective efficacy of A. calamus in the rat model of ischaemia.

Nitric oxide regulates Angiopoietin1/Tie2 expression after stroke

We tested whether the nitric oxide donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) aminio] diazen-1-ium-1,2-diolate (DETA-NONOate), increases expression of Angiopoietin (Ang1)/Tie2, which may play a role in regulating angiogenesis and vascular integrity after stroke in rats. Wistar rats were subjected to middle cerebral artery occlusion and treated with or without DETA-NONOate. Stroke rats treated with DETA-NONOate show significantly increased Ang1, Tie2 and Occludin expression in the ischemic border compared with control stroke animals (p < 0.05). Consistent with in vivo data, DETA-NONOate promotes capillary tube formation in cultured brain endothelial cells. Neutralizing Ang1 antibody attenuates DETA-NONOate-induced capillary tube formation. The data suggest that the Ang1/Tie2 axis promotes DETA-NONOate-induced angiogenesis and stabilizes of angiogenic vessels after stroke.

[Fusion imaging of the 3D MR cisternography/angiography for the assessment of the intracranial major cerebral arterial stenosis]

The fusion imaging of the 3D MR cisternography (MRC) and 3D MR angiography (MRA) was applied for the assessment of the major cerebral arterial stenosis. The outer wall configurations of the stenotic lesions of the intracranial major cerebral arteries within a cisternal space were depicted by 3D MRC. Flow-related vascular structures were shown by 3D MRA. Fusion imaging was created by compositing volumetric data of MRC and co-registered MRA by using a workstation with transparent perspective volume-rendering technique. Stenotic lesions of the intracranial cerebral arteries were assessed as a discrepancy of 3D MRC and 3D MRA findings on a fusion image. Fusion imaging of 3D MRC/MRA could visualize stenotic lesions of the intracranial major cerebral arteries caused by atherosclerotic plaques; and this may provide useful information in the management of acute and chronic ischemic stroke caused by atherosclerosis of the intracranial major cerebral arteries.

Risk Factors for Growth of Unruptured Intracranial Aneurysms: Follow-up Study by Serial 0.5–T Magnetic Resonance Angiography

OBJECTIVE:

The independent risk factors for aneurysm growth were retrospectively investigated in 130 patients with unruptured aneurysms who were followed up by 0.5–T serial magnetic resonance angiography with stereoscopic images.

METHODS:

Age, sex, site of aneurysm, size of aneurysm, multiplicity of aneurysms, type of circle of Willis, length of follow-up period, cerebrovascular event, hypertension, diabetes, hyperlipidemia, smoking habit, and family history of subarachnoid hemorrhage were investigated using multiple logistic analysis.

RESULTS:

Fourteen patients (16 aneurysms) among the 130 patients (159 aneurysms) showed aneurysm growth (10.8%) during follow-up of 10 to 69 months (mean 29.3 ± 10.5 mo). Multiple logistic analysis disclosed that location on the middle cerebral artery (odds ratio [OR] 0.08, P &lt; 0.01), multiplicity of aneurysms (OR 68.5, P &lt; 0.01), aneurysm size of 5 mm or larger (OR 1.17, P = 0.05), and family history of subarachnoid hemorrhage (OR 10.9, P &lt; 0.01) were independent risk factors.

CONCLUSION:

Location on the middle cerebral artery, multiplicity, aneurysm size of 5 mm or larger, and family history of subarachnoid hemorrhage are independent risk factors for aneurysm growth. These results may help to determine the treatment choice for unruptured aneurysms.

Differences between arterial occlusive and cortical photothrombosis stroke models with magnetic resonance imaging and microtubule-associated protein-2 immunoreactivity

The differences between two models of cerebral ischemia [middle cerebral arterial transection (MCAT) and cortical photothrombosis (PT)] were explored with multiparametric MRI of apparent diffusion coefficient trace (ADCtr), cerebral blood flow (CBF) and T1. Microtubule-associated protein-2 (MAP2) immunoreactivity sections aligned with the MR images in the same coronal plane were used to map the infarct and to guide region-of-interest selection. In ischemic cortex, the larger T1 increase in PT versus MCAT (42+/-7% vs. 16+/-5%) is related to the different character of edema between these models; yet, neither CBF nor ADCtr discriminated between them at 3.5 h, suggesting that different mechanisms of ischemic damage to the brain cells resulted in the same ADCtr value. CBF and ADCtr were depressed in immediately adjacent ischemic border by 27+/-7% and 47+/-10%, respectively, in MCAT but not in PT, suggesting marginal perfusion in MCAT. CBF in homotopic normal cortex in the opposite hemisphere was higher for PT compared with MCAT (199+/-20 and 134+/-10 ml/100 g/min, respectively). Different pathological processes in the two models affect CBF, ADCtr and T1 in a unique, regionally specific manner. The PT model differs substantially from the MCAT and is not a model of cortical ischemia with an appreciable border zone.

Cerebral perfusion computerized tomography: influence of reference vessels, regions of interest and interobserver variability

INTRODUCTION

There are still no standardized guidelines for perfusion computerized tomography (PCT) analysis.

METHODS

A total of 61 PCT studies were analyzed using either the anterior cerebral artery (ACA) or the middle cerebral artery (MCA) as the arterial reference, and the superior sagittal sinus (SSS) or the vein of Galen (VG) as the venous reference. The sizes of regions of interest (ROI) were investigated comparing PCT results obtained using a hemispheric ROI combined with vascular pixel elimination with those obtained using five smaller ROIs located over the cortex and basal ganglia. In addition, interobserver variations were explored using a standardized protocol.

RESULTS

MCA-based measurements of cerebral blood flow (CBF) and blood volume (CBV) were in accordance with those obtained with the ACA except in 16 patients with ischemic stroke, in whom CBF was overestimated by the ipsilateral MCA. Venous maximal intensity was significantly lower with the VG when compared with the SSS, resulting in overestimation of CBF and CBV. However, in 13.3% of patients the VG ROI yielded higher maximal intensities than the SSS ROI. There was no difference in PCT results between hemispheric ROI and averaged separate ROI when vascular pixel elimination was used. Finally, interobserver variations were as high as 11% for CBF and 12% for CBV.

CONCLUSION

The present results suggest that pathological rather than anatomical considerations should dictate the choice of the arterial ROI. For venous ROI, although SSS seems to be adequate in most instances, deep cerebral veins may occasionally generate higher maximal intensities and should therefore be selected. Importantly, significant user-dependency should be taken into account.

Cerebral emboli as a potential cause of Alzheimer's disease and vascular dementia: case-control study

OBJECTIVE

To compare the occurrence of spontaneous cerebral emboli and venous to arterial circulation shunts in patients with Alzheimer's disease or vascular dementia and controls without dementia.

DESIGN

Cross sectional case-control study.

SETTING

Secondary care old age psychiatry services, Manchester.

PARTICIPANTS

170 patients with dementia (85 with Alzheimer's disease, 85 with vascular dementia) and 150 age and sex matched controls. Patients on anticoagulant treatment, patients with severe dementia, and controls with marked cognitive impairment were excluded.

MAIN OUTCOME MEASURES

Frequencies of detection of spontaneous cerebral emboli during one hour monitoring of the middle cerebral arteries with transcranial Doppler and venous to arterial circulation shunts by a transcranial Doppler technique using intravenous microbubbles as an ultrasound contrast.

RESULTS

Spontaneous cerebral emboli were detected in 32 (40%) of patients with Alzheimer's disease and 31 (37%) of those with vascular dementia compared with just 12 each (15% and 14%) of their controls, giving significant odds ratios adjusted for vascular risk factors of 2.70 (95% confidence interval 1.18 to 6.21) for Alzheimer's disease and 5.36 (1.24 to 23.18) for vascular dementia. These spontaneous cerebral emboli were not caused by carotid disease, which was equally frequent in dementia patients and their controls. A venous to arterial circulation shunt indicative of patent foramen ovale was found in 27 (32%) Alzheimer's disease patients and 25 (29%) vascular dementia patients compared with 19 (22%) and 17 (20%) controls, giving non-significant odds ratios of 1.57 (0.80 to 3.07) and 1.67 (0.81 to 3.41).

CONCLUSION

Spontaneous cerebral emboli were significantly associated with both Alzheimer's disease and vascular dementia. They may represent a potentially preventable or treatable cause of dementia.

[Changes of electroencephalographic findings in a case of migraine with various neurological symptoms]

We report here an 1-year-old boy who was diagnosed as sporadic hemiplegic migraine demonstrated transient changes in electroencephalographic (EEG) background activity accompanied with migraine attacks. The attacks were associated with various neurological complications such as impairment of consciousness and hemiplegia and so on, which coincided with the changes of EEG findings. When his first headache developed with fever and impairment of consciousness, diffuse slow waves (1-2 Hz, 250-300 microV) appeared transiently. The slow wave gradually improved thereafter, and disappeared on the 24th day. On the 25th day, when he had the second attack with left hemiplegia and impairment of consciousness and sensation, slow waves, (2-3 Hz, 250-300 microV) appeared on right side of the brain. Constriction of the right middle cerebral artery was found on MR angiography at that time. The EEG change had improved to normal background activity 3 days after the episode. This unique case demonstrated that transient EEG changes seem to be correlated with the existence of unconsciousness and the laterality of the ischemic insult. We may assume that the changes of electroencephalographic findings may represent the cortical dysfunction caused by vascular constriction.

Cortical perfusion measurement by indocyanine-green videoangiography in patients undergoing hemicraniectomy for malignant stroke

BACKGROUND AND PURPOSE

Assessment of cerebral perfusion during neurosurgical procedures would be beneficial to identify areas at risk and to guide placement of monitoring probes. Therefore, we have adapted near-infrared indocyanine-green (ICG) videoangiography to assess cortical perfusion intraoperatively.

METHODS

ICG videoangiography was performed intraoperatively in 6 patients after decompressive hemicraniectomy for middle cerebral artery stroke. Flow maps of cortical perfusion were generated with IC-CALC 1.1 software by calculating the ratio of difference in fluorescence intensity and rise time.

RESULTS

Excellent visualization of cerebral arteries, cortical perfusion and collateral circulation via leptomeningeal anastomoses could be demonstrated in all cases. Flow maps revealed high spatial resolution and showed heterogeneous maple-leaf-shaped hypoperfusion. 26.5+/-13.7% and 29.0+/-9.1% of the exposed cortical surface (141+/-18 cm2) demonstrated core and penumbral flow, respectively.

CONCLUSIONS

ICG videoangiography appears to be a valuable tool to precisely detect relative cortical tissue perfusion. Thus, it may provide useful research data on the pathophysiology of human stroke, help surgeons to maintain adequate brain perfusion intraoperatively, and simplify adequate placement of tissue probes to monitor critically hypoperfused brain tissue.

Is IV tissue plasminogen activator beneficial in patients with hyperdense artery sign?

OBJECTIVE

To evaluate the effect of IV recombinant tissue plasminogen activator (rt-PA) in patients with hyperdense artery sign (HAS) on initial CT scan.

METHODS

The authors determined the differential effect of IV rt-PA (0.9 mg/kg) in patients with HAS by testing the interaction of rt-PA and HAS in a logistic regression model after adjusting for age, sex, initial NIH Stroke Scale score (NIHSSS), time to randomization, systolic blood pressure, serum glucose, body temperature, and rt-PA in 616 patients treated within 3 hours of symptom onset. Outcomes evaluated included intracranial hemorrhage, modified Rankin scale (mRS) 0-1, Barthel Index (BI) of > or = 95, Glasgow Outcome Scale (GOS) of 0-1, NIHSSS 0-1, and death at 90 days.

RESULTS

HAS was detected on the initial CT scan in 91 (15%) of the 616 patients by an independent neuroradiologist. Significantly lower rates of mRS 0-1, BI > or = 95, GOS of 0-1, or NIHSSS 0-1 at 90 days were observed among patients with HAS. IV rt-PA significantly increased the rates of mRS 0-1, BI > or = 95, GOS of 0-1, or NIHSSS 0-1 at 90 days after adjusting for potential confounders without any significant modifying effect (interaction) of HAS. Among the 91 patients with HAS, rt-PA use demonstrated a trend or significance for increased adjusted rates of favorable outcomes by mRS (p = 0.04), BI (p = 0.1), GOS (p = 0.03), and NIHSSS (p = 0.01).

CONCLUSION

Although hyperdense artery sign is associated with poor outcome, IV recombinant tissue plasminogen activator may be beneficial in this subgroup of patients with ischemic stroke.

D-amphetamine improves cognitive deficits and physical therapy promotes fine motor rehabilitation in a rat embolic stroke model

BACKGROUND AND PURPOSE

The purpose of this study was to examine the effects of D-amphetamine (D-amph) and physical therapy separately or combined on fine motor performance, gross motor performance and cognition after middle cerebral artery thromboembolization in rats.

METHODS

Seventy-four rats were trained in appropriate cognitive and motor behaviours. Thirteen animals were sham-operated and fifty-nine animals were embolized in the right carotid territory. Animals were randomly assigned to five groups: 1) SHAM (non-embolized, saline), 2) CONTROL (embolized, saline), 3) D-AMPH (embolized, D-amph), 4) THERAPY (embolized, saline + physical therapy) and 5) D-AMPH + THERAPY (embolized, D-amph + physical therapy). Rats of the groups 4-5 underwent d-amph or saline treatment on days 1, 3, 5 and 7 after surgery and were re-trained for 1 h starting 60 min after each treatment. During this time, rats were allowed to voluntarily engage in suitable cognitive or motor behaviours in order to obtain food. Animals from all groups were re-tested during days 21-28 after surgery.

RESULTS

No differences in infarct volumes were observed between the groups of embolized animals. When evaluating performances on days 21-28 after surgery, rats of the SHAM and THERAPY groups had better fine motor performance than those of the CONTROL (P < 0.05), whereas rats of SHAM and D-AMPH groups achieved better cognitive performance than CONTROL rats (P < 0.05). No significant differences were observed between any groups regarding gross motor performance.

CONCLUSIONS

After embolization, physical therapy improved fine motor performance and D-amph accelerated rehabilitation of cognitive performance as observed in the rats of the THERAPY and D-AMPH groups. As a result of the administration of a high dose of D-amph, the rats of the D-AMPH + THERAPY combination group failed to engage in physical therapy during D-amph intoxication, thereby limiting any promotion of rehabilitation by combining physical therapy and D-amph.

Urgent stenting of the M2 (superior) division of the middle cerebral artery after systemic thrombolysis in acute stroke

We report a case of a 54-year-old man who presented with a right middle cerebral artery territory infarct and was treated with systemic thrombolytics. He continued to fluctuate neurologically and, with the use of angiography, was found to have an occlusion of the right M2 artery (superior division). This occlusion was successfully revascularized with a coronary stent.

Cerebral Autoregulation and CO2 Reactivity in Anterior and Posterior Cerebral Circulation During Sevoflurane Anesthesia

The purpose of the study was to compare cerebral autoregulation (CA) and CO2 reactivity (CO2R) between the anterior and posterior circulation under sevoflurane anesthesia. We studied 9 adult ASA physical status I patients (22-47 yr) scheduled for elective orthopedic surgery. Blood flow velocity in the middle cerebral artery (Vmca) and in the basilar artery (Vba) were measured using transcranial Doppler ultrasonography. For CA testing, arterial blood pressure was increased using phenylephrine infusion. CA was quantified with the autoregulatory index (ARI). CO2R was investigated at PaCO2 of 30 +/- 2.8 mm Hg, 39.4 +/- 2.6 mm Hg, and 48.7 +/- 2.8 mm Hg. Linear regression analysis was used for CO2R. We found ARI was preserved in both arteries: ARImca (middle cerebral artery) = 0.72 +/- 0.2; ARIba (basilar artery) = 0.66 +/- 0.2; P = 0.5. With regard to CO2R, Vmca increased with slope of 1.7 cm/s/mm Hg PaCO2, Vba increased with slope of 1.5 cm/s/mm Hg PaCO2; P = 0.83. Absolute Vmca was higher compared with Vba; P < 0.05. We conclude that in healthy individuals under 0.5 MAC of sevoflurane and small-dose remifentanil: 1) mean flow velocities of BA are less than those of MCA; 2) autoregulation and CO2R are preserved in the basilar artery and are similar to those of MCA.

Paradoxically Accelerated Fatal Brain Herniation Following Thrombolytic Therapy in Acute Ischemic Stroke

INTRODUCTION

The use of plasminogen activators (PAs) in acute stroke patients has dual effects. PAs are beneficial by dissolving thrombi occluding an artery, but may be harmful by their proteolytic and excitotoxic actions.

METHODS AND RESULTS

We report two patients with a fatal brain herniation who rapidly deteriorated despite the successful recanalization and the sustained arterial patency or blood flow. Imaging studies taken after the thrombolytic treatment suggested early occurrence of cellular damage and profound breakdown of the blood-brain barrier.

CONCLUSION

Fatal brain edema occurred after persistent reperfusion by the thrombolytic therapy. Paradoxical thrombolytic-induced injury, which has been suggested in experimental studies, might play a role.

Cerebral hemodynamic changes gauged by transcranial Doppler ultrasonography in patients with posttraumatic brain swelling treated by surgical decompression

Object

The use of decompressive craniectomy has experienced a revival in the previous decade, although its actual benefit on patients’ neurological outcome remains the subject of debate. A better understanding of the intracranial pressure dynamics, as well as of the metabolic and hemodynamic brain processes, may be useful in assessing the effect of this surgery on the pathophysiology of the swollen brain. The aim of this study was to use transcranial Doppler (TCD) ultrasonography to examine the hemodynamic changes in the brain after decompressive craniectomy in patients with head injury, in addition to examining the relationship between such hemodynamic changes and the patient’s neurological outcome.

Methods

Nineteen patients presenting with traumatic brain swelling and cerebral herniation syndrome who had undergone decompressive craniectomy with dural expansion were studied prospectively. The TCD ultrasonography measurements were performed bilaterally in both the middle cerebral artery (MCA) and in the distal portion of the cervical internal carotid artery (ICA) immediately prior to and after surgical decompression.

After surgery, the mean blood flow velocity (BFV) rose to 175 ± 209% of preoperative values in the MCA of the operated side, while rising to 132 ± 183% in the contralateral side; the difference between the mean BFV increase in in the MCA of both the decompressed and the opposite side reached statistical significance (p < 0.05). The mean BFV of the extracranial ICA increased to 91 ± 119% in the surgical side and 45 ± 60% in the opposite side. Conversely, the MCA pulsatility index (PI) values decreased, on average, to 33 ± 36% of the preoperative value in the operated side and to 30 ± 34% on the opposite side; the MCA PI value reductions were significantly greater in the decompressed side when compared with the contralateral side (p < 0.05). The PI of the extracranial ICA reduced, on average, to 37 ± 23% of the initial values in the operated side and to 24 ± 34%, contralaterally. No correlation was verified between the neurological outcome and cerebral hemodynamic changes seen on TCD ultrasonography.

Conclusions

Decompressive craniectomy results in a significant elevation of cerebral BFV in most patients with traumatic brain swelling and transtentorial herniation syndrome. The increase in cerebral BFV may also occur in the side opposite the decompressed hemisphere; the cerebral BFV increase is significantly greater in the operated hemisphere than contralaterally. Concomitantly, PI values decrease significantly postoperatively, mainly in the decompressed cerebral hemisphere, indicating reduction in cerebrovascular resistance.

Distal Anterior Cerebral Artery Mirror Aneurysms and Middle Cerebral Artery Aneurysms-Case Report-

A 52-year-old woman presented with bilateral distal anterior cerebral artery (ACA) mirror aneurysms, in addition to two right middle cerebral artery (MCA) aneurysms. The left distal ACA and right MCA aneurysms were clipped through right interhemispheric and right pterional craniotomies. The right distal ACA aneurysm was thrombosed. Distal ACA aneurysms tend to be multiple, but mirror aneurysms are rare, especially in the absence of congenital vascular anomaly. Single stage unilateral craniotomy is recommended for surgical treatment.

EGF and FGF-2 Infusion Increases Post-Ischemic Neural Progenitor Cell Proliferation in the Adult Rat Brain

OBJECTIVE

Epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2) play a critical role in neurogenesis. In the present study, we evaluated the additive effect of administering these two factors on post-ischemic progenitor cell proliferation, survival, and phenotypic maturation in the hippocampal dentate gyrus (DG) and the subventricular zone (SVZ) in the adult rat brain after transient middle cerebral artery occlusion.

METHODS

A combination of EGF+FGF-2 (each 1.44 ng/d) was continuously administered into the lateral ventricles for 3 days, 5-bromodeoxyuridine (BrdUrd) was injected (50 mg/Kg) twice daily for 3 days starting on Day 1 of reperfusion, and cohorts of rats were sacrificed on Day 5 and Day 21 of reperfusion.

RESULTS

Compared with sham controls, ischemic rats showed a significantly higher number of newly proliferated cells in both the DG (by 766 +/- 37%, P < 0.05) and the SVZ (by 650 +/- 43%, P < 0.05). Of the progenitor cells proliferated on Day 5 after ischemia, 41 +/- 6% in the DG and 28 +/- 5% in the SVZ survived to 3 weeks. Compared with vehicle control, the EGF + FGF-2 infusion significantly increased the post-ischemic progenitor cell proliferation (by 319 +/- 40%, P < 0.05 in the DG and by 366 +/- 32%, P < 0.05 in the SVZ) and survival (by 40 +/- 12%, P < 0.05 in the DG and by 522 +/- 47%, P < 0.05 in the SVZ) studied at 5 and 21 days, respectively. Furthermore, of the newly proliferated cells survived to 3 weeks after ischemia, EGF + FGF-2 infusion caused a significantly higher number of neuronal nuclear protein-BrdUrd double-positive mature neurons in the DG (46 +/- 9%, P < 0.05) compared with vehicle control. Neuronal nuclear protein and BrdUrd double-positive mature neurons were also found in the DG. Glial fibrillary acidic protein-positive astrocytes did not show double-positive staining in either region.

CONCLUSION

Specific growth factor infusion enhances post-ischemic progenitor cell proliferation by 5 days of reperfusion and neuronal maturation by 21 days of reperfusion in both the DG and SVZ in the adult rat brain.

Prostaglandin EP1 receptor contributes to excitotoxicity and focal ischemic brain damage

The clinical side effects associated with the inhibition of cyclooxygenase enzymes under pathologic conditions have recently raised concerns. A better understanding of neuroinflammatory mechanisms and neuronal survival requires knowledge of cyclooxygenase downstream pathways, especially PGE2 and its G-protein-coupled receptors. In this study, we postulate that EP1 receptor is one of the mechanisms that propagate neurotoxicity and could be a therapeutic target in brain injury. This hypothesis was tested by pretreating C57BL/6 wildtype mice with the EP1 receptor selective agonist ONO-DI-004 and the selective antagonist ONO-8713, followed by striatal unilateral NMDA injection. Results revealed that ONO-DI-004 increased NMDA-induced lesion volume up to 128.7 +/- 12.0%, while ONO-8713 significantly decreased lesion volume to 71.3 +/- 10.9%, as compared to the NMDA-control group. Neurotoxic EP1 receptor properties were also studied using C57BL/6 EP1 receptor knockout (EP1-/-) mice, which revealed a significant decrease to 74.5 +/- 8.2%, as compared to wildtype controls. The protective effect of the antagonist ONO-8713 was also tested in the EP1-/- mice, revealing no additional protection in these mice. Together, these results support the selectivity of ONO-8713 toward EP1 receptor and suggest the neurotoxic role of EP1 receptor. Furthermore, the EP1 receptor role in ischemic brain damage was investigated using a model of middle cerebral artery occlusion (MCAO) and reperfusion. The infarct volume was significantly reduced to 56.9 +/- 11.5% in EP1-/- mice, as compared to wildtype controls. This is the first study that demonstrates that EP1 receptor aggravates neurotoxicity and that modulation of this receptor can determine the outcomes in both excitotoxic and focal ischemic neuronal damage.