Experimental subarachnoid hemorrhage causes early and long-lasting microarterial constriction and microthrombosis: an in-vivo microscopy study

Early brain injury (EBI) after subarachnoid hemorrhage (SAH) is characterized by a severe, cerebral perfusion pressure (CPP)-independent reduction in cerebral blood flow suggesting alterations on the level of cerebral microvessels. Therefore, we aimed to use in-vivo imaging to investigate the cerebral microcirculation after experimental SAH. Subarachnoid hemorrhage was induced in C57/BL6 mice by endovascular perforation. Pial arterioles and venules (10 to 80 μm diameter) were examined using in-vivo fluorescence microscopy, 3, 6, and 72 hours after SAH. Venular diameter or flow was not affected by SAH, while >70% of arterioles constricted by 22% to 33% up to 3 days after hemorrhage (P<0.05 versus sham). The smaller the investigated arterioles, the more pronounced the constriction (r(2)=0.92, P<0.04). Approximately 30% of constricted arterioles were occluded by microthrombi and the frequency of arteriolar microthrombosis correlated with the degree of constriction (r(2)=0.93, P<0.03). The current study demonstrates that SAH induces microarterial constrictions and microthrombosis in vivo. These findings may explain the early CPP-independent decrease in cerebral blood flow after SAH and may therefore serve as novel targets for the treatment of early perfusion deficits after SAH.

Subarachnoid hemorrhage and intracerebral hematoma: incidence, prognostic factors, and outcome

OBJECTIVE: To analyze the incidence and impact of an intracerebral hematoma (ICH) on treatment and outcome in patients with aneurysmal subarachnoid hemorrhage. METHODS: Data of 585 consecutive patients with subarachnoid hemorrhage from June 1999 to December 2005 were prospectively entered in a database. ICH was diagnosed and size was measured by computed tomographic scan before aneurysm occlusion. Fifty patients (8.5%) presented with an ICH larger than 50 cm3. The treatment decision (coil, clip, or hematoma evacuation) was based on an interdisciplinary approach. Patients were stratified into good (Hunt and Hess Grades I-III) versus poor (Hunt and Hess Grades IV and V) grade, and outcome was assessed according to the modified Rankin Scale at 6 months. RESULTS: Overall, 358 patients presented in good grade, with 4 of them having ICH (1.1%); and 227 patients presented in poor grade, with 46 of them having ICH (20.3%, P < 0.01). In good-grade patients with an ICH (n = 4), a favorable outcome (modified Rankin Scale score of 0-2) was achieved in 1 patient (25%), and in 246 patients (75%) without an ICH (P = 0.053; odds ratio, 0.11). A favorable outcome was achieved in 5 poor-grade patients (12.8%) with an ICH and in 40 patients (23.7%) without an ICH (P = 0.19; odds ratio, 0.47). Time to treatment was significantly shorter in patients with an ICH than without an ICH (median, 7 versus 26 h; P < 0.001) and shortest in patients with favorable outcome (3.5 hours; P < 0.01). CONCLUSION: The current data confirm that the presence of an ICH is a predictor of unfavorable outcome. However, despite large ICHs, a significant number of patients have a good outcome. To achieve a favorable outcome, ultra-early treatment with hematoma evacuation and aneurysm obliteration seems to be mandatory.

Detecting subarachnoid hemorrhage: Comparison of combined FLAIR/SWI versus CT

OBJECTIVES: Aim of this study was to compare the utility of susceptibility weighted imaging (SWI) with the established diagnostic techniques CT and fluid attenuated inversion recovery (FLAIR) in their detecting capacity of subarachnoid hemorrhage (SAH), and further to compare the combined SWI/FLAIR MRI data with CT to evaluate whether MRI is more accurate than CT. METHODS: Twenty-five patients with acute SAH underwent CT and MRI within 6 days after symptom onset. Underlying pathology for SAH was head trauma (n=9), ruptured aneurysm (n=6), ruptured arteriovenous malformation (n=2), and spontaneous bleeding (n=8). SWI, FLAIR, and CT data were analyzed. The anatomical distribution of SAH was subdivided into 8 subarachnoid regions with three peripheral cisterns (frontal-parietal, temporal-occipital, sylvian), two central cisterns and spaces (interhemispheric, intraventricular), and the perimesencephalic, posterior fossa, superior cerebellar cisterns. RESULTS: SAH was detected in a total of 146 subarachnoid regions. CT identified 110 (75.3%), FLAIR 127 (87%), and SWI 129 (88.4%) involved regions. Combined FLAIR and SWI identified all 146 detectable regions (100%). FLAIR was sensitive for frontal-parietal, temporal-occipital and Sylvian cistern SAH, while SWI was particularly sensitive for interhemispheric and intraventricular hemorrhage. CONCLUSIONS: By combining SWI and FLAIR, MRI yields a distinctly higher detection rate for SAH than CT alone, particularly due to their complementary detection characteristics in different anatomical regions. Detection strength of SWI is high in central areas, whereas FLAIR shows a better detection rate in peripheral areas.

Preventing vasospasm improves outcome after aneurysmal subarachnoid hemorrhage: rationale and design of CONSCIOUS-2 and CONSCIOUS-3 trials

Cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH) is a frequent but unpredictable complication associated with poor outcome. Current vasospasm therapies are suboptimal; new therapies are needed. Clazosentan, an endothelin receptor antagonist, has shown promise in phase 2 studies, and two randomized, double-blind, placebo-controlled phase 3 trials (CONSCIOUS-2 and CONSCIOUS-3) are underway to further investigate its impact on vasospasm-related outcome after aSAH. Here, we describe the design of these studies, which was challenging with respect to defining endpoints and standardizing endpoint interpretation and patient care. Main inclusion criteria are: age 18-75 years; SAH due to ruptured saccular aneurysm secured by surgical clipping (CONSCIOUS-2) or endovascular coiling (CONSCIOUS-3); substantial subarachnoid clot; and World Federation of Neurosurgical Societies grades I-IV prior to aneurysm-securing procedure. In CONSCIOUS-2, patients are randomized 2:1 to clazosentan (5 mg/h) or placebo. In CONSCIOUS-3, patients are randomized 1:1:1 to clazosentan 5, 15 mg/h, or placebo. Treatment is initiated within 56 h of aSAH and continued until 14 days after aSAH. Primary endpoint is a composite of mortality and vasospasm-related morbidity within 6 weeks of aSAH (all-cause mortality, vasospasm-related new cerebral infarction, vasospasm-related delayed ischemic neurological deficit, neurological signs or symptoms in the presence of angiographic vasospasm leading to rescue therapy initiation). Main secondary endpoint is extended Glasgow Outcome Scale at week 12. A critical events committee assesses all data centrally to ensure consistency in interpretation, and patient management guidelines are used to standardize care. Results are expected at the end of 2010 and 2011 for CONSCIOUS-2 and CONSCIOUS-3, respectively.

Patients with mild traumatic brain injury: immediate and long-term outcome compared to intra-cranial injuries on CT scan

BACKGROUND: Mild traumatic brain injury (MTBI) defined as Glasgow Coma Scale (GCS) 14 or 15 has shown contradictory short- and long-term outcomes. The objective of this study was to correlate intra-cranial injuries (ICI) on CT scan to neurocognitive tests at admission and to complaints after 1 year. METHODS: Two hundred and five patients with MTBI underwent a CT scan and were examined with neurocognitive tests. After 1 year complaints were assessed by phone interviews. RESULTS: The neurocognitive tests in 51% of the patients showed significant deficits; there was no difference for patients with GCS 14-15, nor was there a difference between patients with ICI to patients without. After 1 year patients with ICI had significantly more complaints than patients without ICI, the most frequent complaint was headache and memory deficits. CONCLUSIONS: No correlation was found between GCS or ICI and the neurocognitive tests upon admission. After 1 year, patients with ICI have significantly more complaints than patients without ICI. No cost savings resulted by doing immediate CT scan on all.

Transdermal nitroglycerin in patients with subarachnoid hemorrhage

Delayed ischemic neurological deficit (DIND) following cerebral vasospasm remains a cause for high morbidity and mortality in patients with subarachnoid hemorrhage (SAH). There is experimental and clinical evidence of positive effects of nitric oxide (NO) donors on cerebral vasospasm. We therefore analysed the effect of transdermal nitroglycerin in patients with SAH measuring transcranial Doppler velocities (TCD), cerebral blood flow (CBF) and DIND. Nitroglycerin was used in a target dose of 14 microg/kg/h. TCD assessment was performed daily. CBF measurements were done using the perfusion CT-technique. Blood pressure, volume intake and vasopressor administration, were registered. Nine patients were randomly assigned either to the nitroglycerin group (N-group) and eight patients in the control group (C-group). Mean TCD values in the extracranial portion of the internal carotid artery (ICA) were lower in the N-group (p<0.005). Mean TCD in the middle cerebral arteries (MCA) showed no difference. The Lindegaard ratio was higher in the N-group (p<0.04). CBF in the N-group was higher than in the C-group (p<0.03). Even though nitroglycerin reduces blood pressure and lowers ICA TCD-values and increases the Lindegaard ratio, a higher CBF was measured in the N-group. Thus, nitroglycerin influences the cerebral vascular tone and increases CBF. SAH therapy with nitroglycerin is possible without increasing the risk of DIND. The exact timing of onset, duration and reduction of nitroglycerin administration in respect to the appearance of vasospasm may have a strong impact on the success of such a therapy.

Decompressive craniectomy in subarachnoid hemorrhage

OBJECT: The aim of this study was to analyze decompressive craniectomy (DC) in the setting of subarachnoid hemorrhage (SAH) with bleeding, infarction, or brain swelling as the underlying pathology in a large cohort of consecutive patients. METHODS: Decompressive craniectomy was performed in 79 of 939 patients with SAH. Patients were stratified according to the indication for DC: 1) primary brain swelling without or 2) with additional intracerebral hematoma, 3) secondary brain swelling without rebleeding or infarcts, and 4) secondary brain swelling with infarcts or 5) with rebleeding. Outcome was assessed according to the modified Rankin Scale (mRS) at 6 months (mRS Score 0-3 favorable vs 4-6 unfavorable). RESULTS: Overall, 61 (77.2%) of 79 patients who did and 292 (34%) of the 860 patients who did not undergo DC had a poor clinical grade on admission (World Federation of Neurosurgical Societies Grade IV-V, p < 0.0001). A favorable outcome was attained in 21 (26.6%) of 79 patients who had undergone DC. In a comparison of favorable outcomes in patients with primary (28.0%) or secondary DC (25.5%), no difference could be found (p = 0.8). Subgroup analysis with respect to the underlying indication for DC (brain swelling vs bleeding vs infarction) revealed no difference in the rate of favorable outcomes. On multivariate analysis, acute hydrocephalus (p = 0.009) and clinical signs of herniation (p = 0.02) were significantly associated with an unfavorable outcome. CONCLUSIONS: Based on the data in this study the authors concluded that primary as well as secondary craniectomy might be warranted, regardless of the underlying etiology (hemorrhage, infarction, or brain swelling) and admission clinical grade of the patient. The time from the onset of intractable intracranial pressure to DC seems to be crucial for a favorable outcome, even when a DC is performed late in the disease course after SAH.

Randomised trial of clazosentan, an endothelin receptor antagonist, in patients with aneurysmal subarachnoid hemorrhage undergoing surgical clipping (CONSCIOUS-2)

We report here results of a randomized, double-blind, placebo-controlled study ( http://www.ClinicalTrials.gov , NCT00558311) that investigated the effect of clazosentan (5 mg/h, n = 768) or placebo (n = 389) administered for up to 14 days in patients with aneurysmal subarachnoid hemorrhage (SAH) repaired by surgical clipping. The primary endpoint was a composite of all-cause mortality, new cerebral infarction or delayed ischemic neurological deficit due to vasospasm, and rescue therapy for vasospasm. The main secondary endpoint was the Glasgow Outcome Scale Extended (GOSE), which was dichotomized. Twenty-one percent of clazosentan- compared to 25% of placebo-treated patients met the primary endpoint (relative risk reduction [RRR] [95% CI]: 17% [-4% to 33%]; p = 0.10). Poor outcome (GOSE score ≤ 4) occurred in 29% of clazosentan- and 25% of placebo-treated patients (RRR: -18% [-45% to 4%]; p = 0.10). In prespecified subgroups, mortality/vasospasm-related morbidity was reduced in clazosentan-treated patients by 33% (8-51%) in poor WFNS (World Federation of Neurological Surgeons) grade (≥III) and 25% (5-41%) in patients with diffuse, thick SAH. Lung complications, anemia and hypotension occurred more frequently with clazosentan. Mortality (week 12) was 6% in both groups. The results showed that clazosentan nonsignificantly decreased mortality/vasospasm-related morbidity and nonsignificantly increased poor functional outcome in patients with aneurysmal SAH undergoing surgical clipping.

Impact of early-onset seizures on grading and outcome in patients with subarachnoid hemorrhage

OBJECT After subarachnoid hemorrhage (SAH), seizure occurs in up to 26% of patients. The impact of seizure on outcome has been studied, yet its impact on grading is unknown. The authors evaluated the impact of early-onset seizures (EOS) on grading of spontaneous SAH and on outcome. METHODS This retrospective analysis included consecutive patients with SAH who were treated at the NeuroCenter, Inselspital, University Hospital Bern, Switzerland, between January 2005 and December 2010. Demographic data, clinical data, and reports of EOS were recorded. The EOS were defined as seizures occurring within 24 hours after ictus. Patients were graded according to the World Federation of Neurosurgical Societies (WFNS) scale pre- and postresuscitation and dichotomized into good (WFNS I-III) and poor (WFNS IV-V) grades. Outcome was assessed at 6 months by using the modified Rankin Scale (mRS); an mRS score of 0-3 was considered a good outcome and an mRS score of 4-6 was considered a poor outcome. RESULTS Forty-one of 425 patients with SAH had EOS. Twenty-seven of those 41 patients (65.9%) had a poor WFNS grade. Twenty-eight (68.3%) achieved a good outcome, 11 (26.8%) had a poor outcome, and 2 (4.9%) were lost to followup. Early-onset seizures were proven in 9 of 16 electroencephalograms. The EOS were associated with poor WFNS grade (OR 2.81, 97.5% CI 1.14-7.46; p = 0.03) and good outcome (OR 4.01, 97.5% CI 1.63-10.53; p = 0.03). Increasing age, hydrocephalus, intracerebral hemorrhage, and intraventricular hemorrhage were associated with poor WFNS grade, whereas only age, intracerebral hemorrhage (p < 0.001), and poor WFNS grade (p < 0.001) were associated with poor outcome. CONCLUSIONS Patients with EOS were classified significantly more often in a poor grade initially, but then they significantly more often achieved a good outcome. The authors conclude that EOS can negatively influence grading. This might influence decision making for the care of patients with SAH, so grading of patients with EOS should be interpreted with caution.

Proenkephalin as marker for severity of aneurysmal subarachnoid hemorrhage: a pilot study

Objective: Several biomarker have shown associations with severity, vasospasm, ischemic events or outcome in aneurysmal subarachnoid hemorrhage. Yet no biomarker is used in daily clinical routine. Previously encephalin peptides were described as new biomarkers in ischemic stroke and traumatic brain injury. We sought to evaluate the usefulness of Proenkephalin A, a precursor protein of encephalin peptides, as biomarker in aneurysmal subarachnoid hemorrhage. Method: Eighteen consecutive patients with aSAH had plasma PENK A levels measured with a validated chemiluminescence sandwich immunoassay. The association of PENK A levels at admission with severity of SAH according to the World Federation of Neurological Surgeons (WFNS) grade after resuscitation was the primary endpoint. Levels of PENK A are analyzed with respect to different clinical and radiological scores as well as between patients with ICH, intraventricular hemorrhage, hydrocephalus, brain edema, vasospasm and ischemia. Results: Good grade patients showed median PENK A levels of 73.9pmol/l (IQR 69-80.4) and poor grade patients 117pmol/l (IQR 86-149). PENK A levels are significantly associated with severity of SAH as graded on the WFNS scale (p=0.03). No other parameter had a significant association. Conclusions: PENK A might be a useful serum marker in aSAH. Yet, larger trials also with serial PENK A assessments are needed.

Reconsidering the logic of World Federation of Neurosurgical Societies grading in patients with severe subarachnoid hemorrhage.

OBJECT Current data show a favorable outcome in up to 50% of patients with World Federation of Neurosurgical Societies (WFNS) Grade V subarachnoid hemorrhage (SAH) and a rather poor prediction of worst cases. Thus, the usefulness of the current WFNS grading system for identifying the worst scenarios for clinical studies and for making treatment decisions is limited. One reason for this lack of differentiation is the use of "negative" or "silent" diagnostic signs as part of the WFNS Grade V definition. The authors therefore reevaluated the WFNS scale by using "positive" clinical signs and the logic of the Glasgow Coma Scale as a progressive herniation score. METHODS The authors performed a retrospective analysis of 182 patients with SAH who had poor grades on the WFNS scale. Patients were graded according to the original WFNS scale and additionally according to a modified classification, the WFNS herniation (hWFNS) scale (Grade IV, no clinical signs of herniation; Grade V, clinical signs of herniation). The prediction of poor outcome was compared between these two grading systems. RESULTS The positive predictive values of Grade V for poor outcome were 74.3% (OR 3.79, 95% CI 1.94-7.54) for WFNS Grade V and 85.7% (OR 8.27, 95% CI 3.78-19.47) for hWFNS Grade V. With respect to mortality, the positive predictive values were 68.3% (OR 3.9, 95% CI 2.01-7.69) for WFNS Grade V and 77.9% (OR 6.22, 95% CI 3.07-13.14) for hWFNS Grade V. CONCLUSIONS Limiting WFNS Grade V to the positive clinical signs of the Glasgow Coma Scale such as flexion, extension, and pupillary abnormalities instead of including "no motor response" increases the prediction of mortality and poor outcome in patients with severe SAH.

Extra-intracranial blood shunt mimicking aneurysm rupture: intracranial-pressure-controlled rabbit subarachnoid hemorrhage model

The achieved degree of delayed cerebral vasospasm (DCVS) in the rabbits most frequently applied cistern magna blood injection model is often mild. The aim of this study was to characterize and evaluate the feasibility of an experimental SAH technique that mimics pathophysiological mechanisms and triggers higher degrees of DCVS.

Preliminary results of an ICP-controlled subarachnoid hemorrhage rabbit model for the study of delayed cerebral vasospasm

INTRODUCTION: Intracisternal blood injection is the most common applied experimental subarachnoid bleeding technique in rabbits. The model comprises examiner-dependent variables and does not closely represent the human pathophysiological sequelae of ruptured cerebral aneurysm. The degree of achieved delayed cerebral vasospasm (DCVS) in this model is often mild. The aim of this study was to characterize and evaluate the feasibility of a clinically more relevant experimental SAH in vivo model. SAH was performed by arterial blood shunting from the subclavian artery into the great cerebral cistern. A total of five experiments were performed. Intracranial pressure (ICP), arterial blood pressure, heart rate, arterial blood gas analysis, and neurological status were monitored throughout the experiments. SAH induced vasoconstriction of the basilar artery was 52.1±3.4% on day 3 compared to baseline (P<0.05). Post-mortem gross examination of the brain showed massive blood clot accumulation around the brainstem and ventral surface of the brain. The novel technique offers an examiner independent SAH induction and triggers high degrees of delayed cerebral vasospasm. The severity of vasospasm attained offers a unique opportunity to evaluate future therapeutic treatment options.

Traumatic subarachnoid hemorrhage, basal ganglia hematoma and ischemic stroke caused by a torn lenticulostriate artery

Subarachnoid hemorrhage (SAH), basal ganglia hematoma (BGH) and ischemic stroke are common diseases with diverging therapies. The simultaneous occurrence of these diseases is rare and complicates the therapy. We report the case of a 30-year-old man with a ruptured lenticulostriate artery after traumatic brain injury that caused the combination of SAH, BGH and ischemic stroke and subsequent cerebral vasospasm. This rupture mimicked the pathophysiology and imaging appearance of aneurysmal SAH. The site of rupture was not secured by any treatment; however, hyperdynamic therapy and percutaneous transluminal angioplasty were feasible in this setting to prevent additional delayed neurological deficit.