Serum Glucose and Potassium Ratio as Risk Factors for Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Cerebral vasospasm is associated with poor prognosis in patients with aneurysmal subarachnoid hemorrhage (SAH), and biomarkers for predicting poor prognosis have not yet been established. We attempted to clarify the relationship between serum glucose/potassium ratio and cerebral vasospasm in patients with aneurysmal SAH.

METHODS

We studied 333 of 535 aneurysmal SAH patients treated between 2006 and 2016 (123 males, 210 females; mean age 59.7 years; range 24-93). We retrospectively analyzed the relationship between cerebral vasospasm grade and clinical risk factors, including serum glucose/potassium ratio.

RESULTS

Postoperative angiography revealed cerebral vasospasm in 112 patients (33.6%). Significant correlations existed between the ischemic complication due to cerebral vasospasm and glucose/potassium ratio (P < .0001), glucose (P = .016), and potassium (P = .0017). Serum glucose/potassium ratio was elevated in the cerebral vasospasm grade dependent manner (Spearman's r = 0.1207, P = .0279). According to the Glasgow Outcome Scale (GOS) score at discharge, 185 patients (55.5%) had a poor outcome (GOS scores 1-3). Serum glucose/potassium ratio was significantly correlated between poor outcome (GOS scores 1-3) and age (P < .0001), serum glucose/potassium ratio (P < .0001), glucose (P < .0001), potassium (P = .0004), white blood cell count (P = .0012), and cerebral infarction due to cerebral vasospasm (P < .0001). Multivariate logistic regression analyzes showed significant correlations between cerebral infarction due to cerebral vasospasm and serum glucose/potassium ratio (P = .018), glucose (P = .027), and potassium (P = .052).

CONCLUSIONS

Serum glucose/potassium ratio in cases of aneurysmal SAH was significantly associated with cerebral infarction due to cerebral vasospasm and GOS at discharge. Therefore, this factor was useful to predict prognosis in patients with cerebral vasospasm and aneurysmal SAH.

[Disturbances of the hemostatic system in patients with aneurysmal subarachnoid hemorrhage]

Subarachnoid hemorrhages due to rupture of cerebral aneurysms are characterized by high mortality. More than 25% of patients who have survived the first hours after aneurysmal SAH (aSAH) develop delayed cerebral ischemia that is one of the main causes of disability. The mechanisms underlying delayed ischemia have not yet been fully understood. Previously, the development of vasospasm was believed to be the only cause for development of delayed ischemia. In recent years, there has been evidence that hemostatic system disorders typical of this category of patients are the cause of cerebral artery thrombosis, which is one of the main pathophysiological mechanisms for the development of delayed cerebral ischemia. This review presents an analysis of published papers on hemostasis disturbances in patients with aSAH, their pathophysiological mechanisms, and their role in the development of cerebral ischemia.

Ficolin-1 Levels in Patients Developing Vasospasm and Cerebral Ischemia After Spontaneous Subarachnoid Hemorrhage

Activation of the inflammatory generating complement system might play a pathogenic role in spontaneous subarachnoid hemorrhage (SAH). We studied whether plasma and cerebrospinal fluid (CSF) levels of complement proteins were associated with angiographic vasospasm and cerebral ischemic lesions after SAH. Ficolin-1 (M-ficolin), ficolin-3 (H-ficolin), mannose-binding lectin (MBL), MBL-associated serine protease 2 (MASP-2), MASP-3, and MAp44 were analyzed in plasma of 45 SAH patients at 24 h after bleeding. Additionally, ficolin-1 levels were measured in cerebrospinal fluid (CSF) samples obtained 24 h after bleeding in 19 patients with external ventricular drainage placement. Angiographic vasospasm was identified using transcranial Doppler or angio-CT and considered symptomatic when new focal deficits or ischemic lesions appeared in follow-up neuroimaging. Functional outcome was assessed using modified Rankin scale (mRS) at 90 days. Higher plasma ficolin-1 levels (ng/ml) at 24 h were associated with poor Hunt and Hess (HH) grade at admission (mean 1158 (SD 360) vs 1654 (871), p = 0.004) and were higher in patients developing angiographic vasospasm (1119.44 (374) vs 1514 (755), p = 0.025) and cerebral ischemia (1067 (325) vs 1610 (766), p = 0.003). In multivariate models adjusted for confounders, higher ficolin-1 remained associated with brain ischemic lesions (OR per 100 ng/ml 1.34, 95 %CI 1.04-1.73, p = 0.026) and vasospasm (OR per 100 ng/ml of increase 1.26, 95 %CI 1.02-1.56, p = 0.031). Patients with angiographic vasospasm and cerebral ischemic lesions had non-significantly lower ficolin-1 concentration in the CSF. Plasma ficolin-1 emerged as a marker of clinical severity and brain ischemia after SAH. Larger studies will be required to establish the therapeutic implications of this finding.

Expression and significance of vWF, GMP-140 and ADAMTS13 in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

The aim of this study was to investigate the role of the von Willebrand factor (vWF) in patients with aneurysmal subarachnoid hemorrhage (aSAH), platelet membrane glycoprotein-140 (GMP-140). The aim is also to discover the expression and clinical significance of von Willebrand factor (vWF) cleaving protease (ADAMTS13).

PATIENTS AND METHODS

83 patients with aSAH were selected from January 2014 to December 2016. The patients were divided into cerebral vasospasm group (CVS group) (n = 37) and no convulsion group (non-CVS group) (n = 46); delayed cerebral ischemia group (DCI group) (n = 31) and non-delayed cerebral ischemia group (non-DCI group) (n = 52). Also, the different aneurysm diameter group included 43 patients in < 5 mm group, 29 patients in 5-10 mm group, 11 patients in > 10 mm group. The number of patients in the good prognosis group and the poor prognosis group were 49 and 34, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of vWF, GMP-140, and ADAMTS13 in plasma of aSAH patients, and the correlation between the indexes was analyzed.

RESULTS

The repeated measures analysis of variance showed that there was no significant difference in plasma vWF, GMP-140, and ADAMTS13 levels in each group of the aSAH patients (p < 0.05). The vWF level of the CVS group was higher than that of the non-CVS group on day 4 and day 10. The GMP-140 level of the CVS group was higher than that of the non-CVS group on day 1, day 4 and day 10. And the ADAMTS13 level was lower than that of the non-CVS group on day 1 and day 10. The difference was statistically significant (p < 0.05). The plasma vWF level of DCI group was higher than that of the non-DCI group on day 1 and day 4. The plasma GMP-140 level at day 4 was higher than that of the non-DCI group. The plasma ADAMTS13 level at day 1 was lower than that in the non-DCI group. The difference was significant (p < 0.05). The plasma vWF level in > 10 mm group was higher than that in < 5 mm group and 5-10 mm group at day 1 and day 4. The plasma vWF level in 5-10 mm group was higher than that in < 5 mm group at day 4. The plasma GMP-140 levels in > 10 mm group were higher than that in < 5 mm group and 5-10 mm group at day 1 and d ay 4. The plasma GMP-140 level in 5-10 mm group was higher than that in < 5 mm group at day 1. The plasma ADAMTS13 level in > 10 mm group was lower than that in < 5 mm group and 5-10 mm group on day 1. Moreover, the plasma ADAMTS13 level in 5-10 mm group was lower than that in < 5 mm group: p < 0.05. The plasma vWF level in the good prognosis group was lower than that in the poor prognosis group on day 4 and day 10. On day 1, day 4, and day 10, the level of GMP-140 was lower than that of the poor prognosis group. The ADAMTS13 level on day 1 and day 4 was higher than that in the poor prognosis group. The difference was statistically significant (p < 0.05). Pearson product moment correlation analysis showed that the plasma vWF level was positively correlated with GMP-140 at day 1 (r = 0.334, p < 0.05), negatively correlated with ADAMTS13 (r = -0.426, p < 0.05), and GMP-140 was negatively correlated with ADAMTS13 (r = -0.398, p < 0.05). At day 4, plasma vWF was positively correlated with GMP-140 (r = 0.278, p < 0.05), negatively correlated with ADAMTS13 (r = -0.311, p < 0.05), and GMP-140 was negatively correlated with ADAMTS13 (r = -0.235, p < 0.05). At day 10, there was no significant correlation between vWF, GMP-140, and ADAMTS13 (p > 0.05).

CONCLUSIONS

VWF, GMP-140, and ADAMTS13 were correlated with the diameters and prognoses of CVS, DCI, aneurysms. Combined detection can help to evaluate the condition of patients with aSAH, so as to provide a guide for clinical treatment and prognosis.

[Content of C-reactive protein in patients in an acute period of a ruptured intracranial aneurysm]

A content of C-reactive protein (CRP) in the blood serum was determined in 36 patients in acute period of a ruptured intracranial arterial aneurysm (AA). It was significantly more, than in a control group, and have exceeded 10 mg/I in 1 - 4th day of the disease. The level of CRP have had differ, depending on severity of cerebral vasospasm (CVS), determined in accordance to the ultrasound investigation data. In a pronounced CVS in majority of patients the level of CRP in the blood serum have had exceed 10 mg/l, and have secured elevated in a spinal liquor on the 7 - 10th day of the disease, differing from this index in patients with moderately pronounced CVS or without it. In patients with severe invalidization or those, who have died, the level of CRP was trust-worthy higher.

Multiplexed protein profiling after aneurysmal subarachnoid hemorrhage: characterization of differential expression patterns in cerebral vasospasm

Cerebral vasospasm is a major contributor to delayed morbidity following aneurysmal subarachnoid hemorrhage. We sought to evaluate differential plasma protein levels across time in patients with aneurysmal subarachnoid hemorrhage to identify potential biomarkers and to better understand the pathogenesis of cerebral vasospasm. Nine female patients with aneurysmal subarachnoid hemorrhage underwent serial analysis of 239 different serum protein levels using quantitative, multiplexed immunoassays (DiscoveryMAP 250+ v2.0, Myriad RBM, Austin, TX, USA) on post-hemorrhage days 0 and 5. A repeated measures analysis of variance determined that mean protein concentration decreased significantly in patients who developed vasospasm versus those who did not for alpha-2-macroglobulin (F [1.00,7.00]=16.33, p=0.005), angiogenin (F [1.00,7.00]=7.65, p=0.028), apolipoprotein A-IV (F [1.00,7.00]=6.308, p=0.040), granulocyte colony-stimulating factor (F [1.00,7.00]=9.08, p=0.020), macrophage-stimulating protein (F [1.00,7.00]=24.21, p=0.002), tetranectin (F [1.00,7.00]=5.46, p<0.039), vascular endothelial growth factor receptor 3 (F [1.00,7.00]=6.94, p=0.034), and significantly increased for vitronectin (F [1.00,7.00]=5.79, p=0.047). These biomarkers may be of value in detecting cerebral vasospasm, possibly aiding in the identification of patients at high-risk prior to neurological deterioration.

A randomised controlled trial of induced hypermagnesaemia following aneurysmal subarachnoid haemorrhage

BACKGROUND

The effect of serum magnesium concentration on the incidence of cerebral arterial vasospasm following aneurysmal subarachnoid haemorrhage (SAH) is unclear.

OBJECTIVE

To test whether induced hypermagnesaemia reduces the incidence of cerebral arterial vasospasm following aneurysmal SAH.

METHODS

The study was conducted at two tertiary hospitals in Australia and patients were recruited between 1 April 2005 and 31 December 2009. Within 72 hours of aneurysmal SAH, patients were randomly assigned to a high or normal target for serum magnesium concentration (1.60-2.50 mmol/L or 0.65-1.05 mmol/L, respectively). The primary end point was cerebral arterial vasospasm diagnosed by blinded assessment of digital subtraction angiography. Secondary outcomes included severity of vasospasm and functional recovery at 90 days. Analysis was by intention to treat.

RESULTS

Of 162 patients, 81 were assigned to the normal range group and 81 were assigned to the high-range group; the primary outcome was available for 78 and 79 patients, respectively. The groups had similar baseline characteristics. Vasospasm occurred in 40 patients (50.6%) and 50 patients (64.1%) assigned to high-range and normal-range groups, respectively (adjusted OR, 0.51; 95% CI, 0.26-1.02; P = 0.06). At 90 days, neurological recovery between the groups was not significantly different (adjusted OR for worse outcome, 0.71; 95% CI, 0.39-1.32; P = 0.28). Patients in the high-range group were treated with more noradrenaline to support arterial blood pressure (79 [16- 218] mg) v 59 [14-129] mg; P = 0.03) and had lower mean (SD) serum calcium concentration (1.9 [0.2] mmol/L v 2.1 [0.2] mmol/L, P < 0.001).

CONCLUSION

Patients assigned a higher serum magnesium concentration had a reduced incidence of vasospasm as seen by angiography, but the difference was not statistically significant. Clinically significant outcomes were not different between groups. A firm recommendation for induced hypermagnesaemia cannot be made from this study.

TRIAL REGISTRATION NUMBER

ACTRN12605000058673.

Protein biomarkers in patients with subarachnoid hemorrhage, vasospasm, and delayed ischemic neurological deficits

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating neurological disease. It has many sequelae, including vasospasm and delayed ischemic neurological deficits (DINDs). We explored the blood proteome in patients with aSAH using transcranial Doppler (TCD) velocity as a guide to patients who are at risk for symptomatic vasospasm and DIND. Blood was drawn on all days that patients were observed in the neurocritical care unit (NCCU) after aSAH. A team of neurologists and neurosurgeons identified patients with clinical evidence of vasospasm and DIND. Serum was fractionated using protein chips and surface-enhanced laser desorption and ionization time-of-flight mass spectrometry (SELDI-TOF MS). We detected a pattern of protein expression associated with those at risk for elevated TCD velocities by day 8, compared with blood collected in the presymptomatic stage (days 1-3). We further analyzed serum using pooled samples from study entry to the time of elevated TCD velocities using a protein microarray that analyzed 500 human proteins thematically oriented toward inflammation. After identifying several candidates with elevated concentrations in the pooled samples, we then used reverse protein arrays to quantitate the concentration of potential candidate proteins in the individual samples. Proteins with significantly elevated concentrations included apolipoprotein-E, apolipoprotein-A, serum amyloid protein-4, and serum amyloid protein-P. Future studies in larger sample populations are needed to evaluate these biomarkers further as representative of biosystems involved in vasospasm and DIND or as potential biomarkers predictive of risk associated with disease.

[Effects of puerarin on the vascular active factor related to cerebral vasospasm after aneurysm subarachnoid hemorrhage]

OBJECTIVE

To investigate the effects and possible mechanisms of puerarin on the vascular active factors correlated to cerebral vasospasm (CVS) after aneurysm subarachnoid hemorrhage (aSAH).

METHODS

Fifty-four patients with aSAH were randomly assigned to the puerarin group (30 cases) and the control group (24 cases) by lot. On the basis of routine treatment, the patients in the puerarin group were intravenously dripped with 0.5 g puerarin by adding in 250 mL glucose injection once daily. The injection was given starting from the 3rd day of the disease course, for 14 successive days. The plasma levels of nitric oxide (NO), endothelin-1 (ET-1), thromboxane B, (TXB2), 6-Keto-prostaglandin F1alpha (6-K-PGF1alpha) were compared between the two groups pre- and post-therapy. The incidence of cerebral vasospasm (CVS) was observed using transcranial Doppler (TCD). The Glasgow outcome scale (GOS) were compared at discharge between the two groups.

RESULTS

Compared with the control group, the plasma levels of NO, ET-1, and 6-K-PGF1alpha increased in the puerarin group (P < 0. 05), the TXB2 level decreased (P < 0.05), the incidence of CVS decreased (P < 0.05), the mean MCA velocity increased (P < 0.05), and the GOS at discharge increased (P < 0.05).

CONCLUSIONS

Puerarin is an effective agent for the prophylaxis and treatment of the CVS in patients after aSAH. Moreover, it can improve the prognosis. The mechanism might be correlated with improving the levels of the vascular active factors, i.e., increasing the plasma levels of NO and PGl2, decreasing TXA, in plasma, increasing the cerebral blood flow, and improving cerebral perfusion.

Serum hyaluronidase levels in patients with aneurysmal subarachnoid haemorrhage

INTRODUCTION

The purpose of this study was to investigate the time course(s) of the serum hyaluronidase levels in patients with aneurysmal subarachnoid haemorrhage and to show whether there is a correlation between symptomatic vasospasm and serum levels of hyaluronidase.

METHODS

This prospective, open, non-randomised clinical study consisted of 20 patients with aneurysmal subarachnoid haemorrhage, and eight patients with normotensive hydrocephalus who served as the control group. Serum hyaluronidase levels were detected within the first three days, days five and seven after aneurysmal subarachnoid haemorrhage, and the results were compared with those from the control group. The results were also compared with those of the clinical parameters, including the patient's outcome at six months and symptomatic vasospasm.

RESULTS

Mean serum hyaluronidase levels were higher on days five and seven, and comparisons with either day five (p-value is 0.001) and/or day seven (p-value is 0.00001) showed a statistical difference between subarachnoid haemorrhage and controls. However, no relationship was found between elevated serum hyaluronidase levels and the clinical parameters including symptomatic vasospasm (p-value is greater than 0.05) and outcome at sixth months (p-value is greater than 0.05).

CONCLUSION

Our results indicate that serum hyaluronidase is elevated in the acute stage(s) of subarachnoid haemorrhage; however, no difference was found between serum hyaluronidase levels and subarachnoid haemorrhage severity. Clinical studies with larger population of patients with aneurysmal subarachnoid haemorrhage are required.

[Effects of tetramethylpyrazine on endothelin and nitric oxide contents in plasma and cerebrospinal fluid after subarachnoid hemorrhage]

OBJECTIVE

To observe the variation of endothelin (ET) and nitric oxide (NO) in plasma and cerebrospinal fluid (CSF) in rabbits, and evaluate the effects of tetramethylpyrazine (TMP) on the prevention and cure of cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH).

METHODS

24 New Zealand rabbits were randomly assigned into three groups: contrast group, experiment group and blank group. Every group contained 8 rabbits. SAH was established according to inject blood into the cisterna magna. The experiment group was administrated with TMP (20 mg/kg x d) transperitoneally. ET and NO of plasma and CSF were detected by radical immunoassay at 72 h and 168 h after SAH. Neurofunction were detected in every group at all the time scales.

RESULTS

(1) After SAH, the level of ET in CSF increased significantly in contrast group compared with that in experiment and blank groups (P<0.05). The value of ET at 168 h was higher than that at 72 h. The level of ET in plasma increased significantly in contrast group compared with blank and experiment groups (P<0.05), and no significant contrast could be found between blank and experiment group. (2) After SAH, the value of NO in CSF was lower in contrast group than in other groups (P<0.05), and the level of NO in CSF continued to decrease in all groups on some extent. As time went by, no significant contrast could be found in all groups. The value of NO in plasma was lower in contrast group than in other groups (P<0.05). There was no significant difference between experiment and blank groups. (3) The neuro-function score continued to be increased in contrast group, but decreased in experiment one. The neuro-function score was lower in experiment group than in contrast one at every time point (P<0.05).

CONCLUSION

After administration of TMP, the variation of ET has the continued decrease in plasma and CSF; the variation of NO shows the continued increase in plasma and CSF; neurological function gets possibly protected. TMP may prevent from and cure CVS after SAH.

Attenuation of experimental subarachnoid hemorrhage-induced increases in circulating intercellular adhesion molecule-1 and cerebral vasospasm by the endothelin-converting enzyme inhibitor CGS 26303

OBJECT

Adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin, are important mediators of inflammation, and their levels are elevated in the serum of patients following aneurysmal subarachnoid hemorrhage (SAH). The investigators previously found that CGS 26303 is effective in preventing and reversing arterial narrowing in a rabbit model of SAH. The purpose of the present study was to examine whether levels of adhesion molecules are altered after treatment with CGS 26303 in this animal model.

METHODS

New Zealand White rabbits were each injected with 3 ml of autologous blood in the cisterna magna, and intravenous treatment with CGS 26303 (30 mg/kg) was initiated 1 hour later. The compound was subsequently administered at 12, 24, and 36 hours post-SAH. Blood samples were collected at 48 hours post-SAH to measure ICAM-1, VCAM-1, and E-selectin levels. After the rabbits had been killed by perfusion-fixation, the basilar arteries (BAs) were removed and sliced, and their cross-sectional areas were measured. Treatment with CGS 26303 attenuated arterial narrowing after SAH. Morphologically, corrugation of the internal elastic lamina of BAs was prominently observed in the SAH only and vehicle-treated SAH groups, but not in the CGS 26303-treated SAH group or in healthy controls. There were no significant differences in the levels of VCAM-1 among the four groups. The levels of E-selectin were increased in all animals subjected to SAH (those in the SAH only, SAH plus vehicle, and SAH plus CGS 26303 groups) compared with healthy controls (no SAH); however, the levels of ICAM-1 in the SAH only and SAH plus vehicle groups were significantly elevated (p < 0.001), and treatment with CGS 26303 reduced ICAM-1 to control levels following SAH.

CONCLUSIONS

These results show that ICAM-1 may play a role in mediating SAH-induced vasospasm and that a reduction of ICAM-1 levels after SAH may partly contribute to the antispastic effect of CGS 26303.

A study of possible correlation between subarachnoid haemorrhage related vasospasm and the post-bleed blood platelet count chart in a Caucasian population

INTRODUCTION

There has been controversy about the aetiology and pathophysiology of subarachnoid haemorrhage (SAH) related vasospasm. Several pathogenic factors like endothelin and adhesion molecules have been discussed. A recently published study concerning an exclusively Asian population suggested a relationship between SAH related vasospasm and the blood platelet count. The aim of our study was to examine this relationship in a European population.

METHOD

We carefully reviewed 88 patients with aneurysmal SAH (54 females, 34 males; mean age 52.5 years, range from 22 to 78 years) treated in our centre with regard to the occurrence of vasospasm and the blood platelet count in a ten day interval after initial SAH. Symptomatic vasospasm was defined as a focal neurological deficit or deterioration in the level of consciousness with or without confirmation of infarction on a CT scan. Thirty-seven patients (42%) developed clinically relevant vasospasm.

RESULTS

There was no statistically significant correlation between the blood platelet count chart (maximum and minimum values) and vasospasm or clinical outcome; we also found no gender or age-related influence on the above mentioned relationships.

CONCLUSIONS

In our opinion there appears to be a difference between Caucasian and Asian populations regarding the influence of platelets in the pathophysiology of SAH and vasospasm.

Hyponatremia and cerebrovascular spasm in aneurysmal subarachnoid hemorrhage

BACKGROUND

Hyponatremia develops in approximately a third of patients with aneurysmal subarachnoid hemorrhage (SAH). Studies have been conflicting about the association between hyponatremia and cerebrovascular spasm (CVS).

AIMS

To investigate whether hyponatremia can signal the onset of CVS.

SETTINGS AND DESIGN

Retrospective chart review of all patients with SAH treated at a tertiary-care university hospital from January to May 2002.

MATERIALS AND METHODS

106 patients were included in the study. Serum sodium levels were recorded from days 1 to 14 of hospitalization. Hyponatremia was defined as serum sodium level<135 meq/l and a fall in sodium level of >4 meq/l from the admission sodium level. The presence of CVS was determined by transcranial doppler sonography. Patients were assigned to one of four groups based on the presence or absence of CVS and hyponatremia.

STATISTICAL ANALYSIS

Student's t-test was used for comparison of means. A logistical regression model was constructed and odds ratios (OR) were calculated.

RESULTS

41 patients developed hyponatremia and 44 developed CVS. Among the 41 with hyponatremia, 22 (54%) had evidence of CVS, whereas among the 65 patients without hyponatremia, 22 (34%) had evidence of CVS (P=0.023). Among those with hyponatremia, the mean sodium drop was 7.9 meq/L in those with CVS compared to 7.0 meq/L in those without CVS (P=0.068). More than half of those with hyponatremia and CVS (13/22) developed hyponatremia at least a day before CVS was diagnosed.

CONCLUSION

In patients with SAH, hyponatremia is associated with a significantly greater risk of developing CVS and may precede CVS by at least one day.

S-100B and NSE: markers of initial impact of subarachnoid haemorrhage and their relation to vasospasm and outcome

S100-B and neuron specific enolase (NSE) are known predictors of outcome in head injured and stroke patients. This study was conducted to test the hypothesis that S-100B and NSE can predict the development of vasospasm and outcome within the first 3 days after subarachnoid haemorrhage (SAH). Fifty-one SAH patients (mean age 51+/-11 years, male : female ratio 1.0 : 1.6, mean World Federation of Neurological Surgeons [WFNS] Grade 3+/-1.5) were included in the study. S100-B and NSE were recorded in venous blood across the first 3 days post-SAH. Vasospasm was diagnosed if mean blood flow velocity of the middle cerebral artery was greater than 120 cm/s and Lindegaard ratio >3. Glasgow Outcome Score (GOS) and cranial CT scans were recorded at 6 months. Normal, intermediate and high S-100B values were seen in 24%, 51% and 25% of patients, respectively. In patients with S-100B>1 microg/L, Fisher Grade 4 and WFNS 4-5 were both seen in 77% of cases. S-100B was significantly higher in those patients who did not develop vasospasm. In addition, S-100B values were significantly higher in those patients who died than in those with unfavourable or favourable outcome. NSE was normal, intermediate and high in 82%, 8% and 10% of patients, respectively. Patients with WFNS 4-5 and/or Fisher Grade 4 had significantly higher NSE values than all others. Across the first 3 days after SAH, measuring S-100B is useful to predict outcome and vasospasm.

ICAM-1 and VCAM-1 expression following aneurysmal subarachnoid hemorrhage and their possible role in the pathophysiology of subsequent ischemic deficits

BACKGROUND

The pathophysiology of ischemic cerebral lesions following aneurysmal subarachnoid hemorrhage (SAH) is poorly understood. There is growing evidence that inflammatory reactions could be involved in the pathogenesis of such delayed occurring ischemic lesions. The aim of this study was to evaluate adhesion molecules with regard to these lesions following SAH.

METHODS

Serum and cerebrospinal fluid (CSF) samples were taken daily from 15 patients up to day 9 after SAH and evaluated for intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1).

RESULTS

CSF and serum samples correlated well during nearly the whole time course (p < 0.0001). A secondary increase in ICAM-1 and VCAM-1 in the serum and CSF correlated with an increase in flow velocity in the transcranial Doppler (p > 0.0001 and p < 0.007) but not to a delayed lesion in the CT scan.

CONCLUSION

We believe that inflammatory processes are involved in the pathogenesis of cerebral vasospasm but they might only be a part of a multifactorial pathogenesis.

Possible Role of the C-Reactive Protein and White Blood Cell Count in the Pathogenesis of Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage

The delayed ischemic neurologic deficit (DIND) is a common and potentially devastating complication in patients who have sustained subarachnoid hemorrhage (SAH). Recent evidence suggests that various constituents of the inflammatory response may be critical in the pathogenesis of this ischemic complication. The aim of this study was to evaluate the possible relationship between the C-reactive protein (CRP)/white blood cell (WBC) count and DIND. A total of 88 patients with acute SAH were included. CRP and WBC count were estimated on a daily basis. Outcome was evaluated 1 year after the initial ictus according to the Glasgow Outcome Scale. CRP levels on days 5, 6, 7, and 8 were statistically significantly higher in the group of patients developing a DIND (P < 0.025, P < 0.016, P < 0.011, P < 0.0002). WBC counts were higher in this patient group on days 1, 4, 5, 6, and 7 (P < 0.0253, P < 0.0087, P < 0.00167, P < 0.0026, P < 0.0045). Overall CRP values were higher with increasing severity of the initial ictus according to the Hunt and Hess Scale and to the outcome according to the Glasgow Outcome Scale from day 3 on. A statistically significant relationship between WBCs and outcome could not be observed. The presented data do not prove that WBCs and CRP values have a direct contribution to the pathogenesis of ischemic complications following SAH, but it supports the assertion that inflammation may present a common pathogenic pathway in the development of such complications.

Endothelin-1 in plasma, cisternal CSF and microdialysate following aneurysmal SAH

OBJECTIVE

Endothelin-1 (ET-1) is postulated to play an important role in the development of cerebral vasospasm (CVS) following SAH. This study was conducted to investigate the time course of ET-release in three different sources: CSF, plasma and microdialysate.

METHODS

In a prospective study ET-1-concentrations were measured in plasma, cisternal CSF and microdialysate in 20 patients with aneurysmal SAH for at least 8 days after hemorrhage.

RESULTS

ET-1 concentration in microdialysate was almost four times higher compared to CSF and plasma. (p<0.001) Only in CSF ET-1-release showed a significant increase over time with highest values on day 5 post ictus (p = 0.03). This was parallel to the increase of transcranial Doppler velocities. ET-1 in plasma and microdialysate did not change over time.

CONCLUSION

ET-1 may have a different biological function in different biological tissues. Only ET-1 in CSF seemed to be associated with CVS.

Serum magnesium levels as related to symptomatic vasospasm and outcome following aneurysmal subarachnoid hemorrhage

INTRODUCTION

Recent evidence suggests that magnesium may be neuroprotective in the setting of cerebral ischemia, and therapeutic magnesium infusion has been proposed for prophylaxis and treatment of delayed ischemic neurological deficit (DIND) resulting from vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). We studied the association between serum magnesium levels, the development of DIND, and the outcomes of patients with SAH.

METHODS

We studied 128 consecutive patients with aneurysmal SAH treated at our institution between 1990 and 1997 who had a serum magnesium level measured at least once during the acute phase of their hospitalization. Delayed ischemic neurological deficit was defined as severe (major focal deficit or coma), moderate (incomplete focal deficit or decreased sensorium without coma), or none.

RESULTS

There was no significant difference in mean, minimum, or maximum serum magnesium levels between patients with and without DIND (1.93, 1.83, 2.02 versus 1.91, 1.84, 1.97 mg/dL, respectively). Similarly, no difference was found in mean serum magnesium levels among patients with severe (1.94 mg/dL), moderate (1.92 mg/dL), or no DIND (1.91 mg/dL). Analyses of serum magnesium levels before (0-4 days following SAH), during (4-14 days following SAH), and after (greater than 14 days following SAH) the period of highest risk for vasospasm revealed no association with the development or severity of DIND. Permanent deficit or death resulting from vasospasm and Glasgow Outcome Scale score at longest follow-up were similarly unaffected by serum magnesium levels overall or during any time interval. Forty (31.5%) patients were hypomagnesemic (less than 1.7 mg/dL) during hospitalization, but no difference in outcome (p = 0.185) or development of DIND (p = 0.785) was found when compared to patients with normal (1.7-2.1 mg/dL) or high (greater than 2.1 mg/dL) magnesium serum levels.

CONCLUSION

We identified no relationship between serum magnesium levels and the development of DIND or outcome following aneurysmal SAH. Based on these data, magnesium supplementation to normal or high-normal physiological ranges seems unlikely to be beneficial for DIND resulting from vasospasm. However, no inference can be made regarding the value of therapeutic infusion of magnesium to supraphysiological levels.

Endothelin-1 levels in plasma and cerebrospinal fluid of patients with cerebral vasospasm after aneurysmal subarachnoid hemorrhage

BACKGROUND

Plasma and cerebrospinal fluid (CSF) concentrations of endothelin-1 (ET-1) were measured in patients with subarachnoid hemorrhage (SAH) after aneurysmal rupture and compared with levels of ET-1 in volunteers. We analyze the relationship between levels of ET-1 in both CSF and plasma with the risk of developing cerebral vasospasm (CVS).

METHODS

Cerebrospinal fluid and blood samples were collected from 30 selected patients after SAH and from 10 healthy volunteers who were used as control. All samples were stored at -70 degrees C and the levels of ET-1 in CSF and blood were measured by using enzyme-linked immunosorbent assay and Western blot. All patients were submitted to angiography to confirm vasospasm.

RESULTS

From the 30 patients admitted at different days of SAH, 18 (60%) developed clinical CVS and 10 (33%) presented angiographic CVS. The levels of ET-1 in the CSF were significantly higher (P = .0001) in patients (1.618 +/- 1.05 fmol/mL) than in controls (0.365 +/- 0.328 fmol/mL). There was statistical difference (P < .05) in CSF levels of ET-1 between each group of the Hunt-Hess scale and controls. The mean plasma concentration of ET-1 was similar (P > .05) in the control group (1.531 +/- 0.753 fmol/mL) and in patients with SAH (1.920 +/- 1.15 fmol/mL).

CONCLUSIONS

These findings indicate that a significant rise in ET-1 levels in the CSF, but not in the plasma, occurs in patients who develop CVS after SAH. Our observation suggests that ET-1 might be involved in the pathogenesis of SAH-associated CVS.

Cerebral salt wasting in subarachnoid hemorrhage rats: model, mechanism, and tool

Cerebral salt wasting (CSW) frequently occurs concomitantly with aneurysmal subarachnoid hemorrhage (SAH). CSW induces excessive natriuresis and osmotic diuresis, and reduces total blood volume. As a result, the risk of symptomatic cerebral vasospasm may be elevated. Therefore, it is important to determine the mechanism of CSW. The purpose of this study was to evaluate whether the rat SAH model exhibits CSW and to investigate the relationship between CSW and natriuretic peptides. A SAH model was produced in 24 rats by perforating a cerebral artery with a nylon thread up through the common carotid artery. To evaluate CSW, urine was cumulatively collected from SAH onset to 12 hours and sodium (Na) excretion was analyzed. Body weight and hematocrit were analyzed before and after SAH onset. Concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in plasma were also analyzed. Urine volume and total Na excretion of SAH rats were significantly higher than those of sham rats (p<0.05). Body weight of SAH rats significantly decreased and hematocrit significantly increased (p < 0.05). ANP concentration was significantly decreased in SAH rats (p<0.05). However, BNP concentrations did not change. This study demonstrated for the first time that a rat SAH model exhibited CSW. It was suggested that the cause of CSW was neither ANP nor BNP. In addition, this rat SAH model will be useful for study of CSW after SAH.

Cervical spinal cord stimulation increases cerebral cortical blood flow in an experimental cerebral vasospasm model

BACKGROUND

Cerebral microcirculatory changes during cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH) are still controversial and uncertain. The aim of our study is to demonstrate that spinal cord stimulation (SCS) augments cerebral cortical microcirculatory blood flow in an experimental cerebral vasospasm model by using Laser Doppler Flowmetry (LDF).

METHOD

The experiments were carried out on 24 New Zealand rabbits. Three experimental groups were designed. In group 1, Cerebral cortical blood flow (CCoBF) was evaluated by LDF in 8 rabbits. In group 2, Intracisternal saline injection and cervical epidural electrode placement without SCS were performed in 8 animals before LDF. In group 3, LDF was performed before and after SCS on the 4th day of SAH in 8 rabbits. CCoBF parameters obtained from LDF data were compared.

FINDINGS

The occurrence of vasospasm after SAH was demonstrated with significant changes in LDF values. In all SAH animals, SCS resulted in significant increase (approximately 30%) in CCoBF. This increase was observed to continue even after the cessation of the stimulation.

CONCLUSIONS

These results indicate that SCS improves cortical ischemia due to vasospasm after induced SAH. The cervical SCS may constitute a new therapeutic modality in treating disturbed CCoBF due to vasospasm.

Prevention of vasospasm by anti-CD11/CD18 monoclonal antibody therapy following subarachnoid hemorrhage in rabbits

OBJECT

Adhesion of leukocytes and their migration into the periadventitial space may be critical in the pathophysiology of vasospasm following subarachnoid hemorrhage (SAH). The cell adhesion molecules involved in this process are lymphocyte function-associated antigen-1 (CD11a/CD18) and macrophage antigen-1 (CD11b/CD18), which are present on neutrophils/macrophages, and intercellular adhesion molecule-1 (CD54), which is present in endothelial cells. A humanized monoclonal antibody (mAb), Hu23F2G, targets CD11/CD18 and prevents leukocyte adhesion to endothelial cells. In this study, systemic administration of Hu23F2G prevented vasospasm in the rabbit model of SAH.

METHODS

Twenty-six New Zealand White rabbits were injected with autologous blood into the cisterna magna to induce SAH, after which they were randomized to receive injections of either Hu23F2G (10 animals) or a placebo at 30 minutes and 24 and 48 hours after SAH (six animals). Control animals underwent sham operations (four animals) or SAH alone (six animals). The animals were killed 72 hours after SAH, their bodies perfused and fixed, and their basilar arteries processed for morphometric analysis. Peripheral white blood cells (WBCs) were counted at 72 hours. The percentages of lumen patency were compared using the Student t-test. The presence of neutrophils and macrophages was confirmed by immunohistochemical analysis in which a rat anti-rabbit anti-CD18 mAb and cresyl violet were used. Treatment with Hu23F2G resulted in the significant prevention of vasospasm. Animals treated with Hu23F2G had 90 +/- 7% lumen patency compared with 65 +/- 7% in the placebo group (p = 0.025). The percentage of lumen patency in the SAH-only group was 59 +/- 10%. The mean WBC count was 16,300 +/- 2710/microl in the treatment group, compared with 7000 +/- 386/microl in the control group (p = 0.02). Administration of Hu23F2G produced increased numbers of WBCs in 70% of the animals treated.

CONCLUSIONS

This study supports the concept that leukocyte-endothelial cell interactions play an important role in the pathophysiology of chronic vasospasm after SAH. Systemic therapy with an anti-CD11/CD18 mAb prevents vasospasm after SAH by inhibiting adhesion of neutrophils and macrophages and their migration into the periadventitial space.

A Pilot Study of Dendroaspis Natriuretic Peptide in Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE:

Hypovolemia after aneurysmal subarachnoid hemorrhage (SAH) may be mediated by natriuretic peptides and can further impair cerebral perfusion in dysau-toregulated and vasospastic arterial territories. Dendroaspis natriuretic peptide (DNP), derived from the venom of Dendroaspis augusticeps, the Green Mamba snake, has recently been discovered in human plasma and atrial myocardium. There is no information regarding the presence or putative role of this peptide in patients with aneurysmal SAH.

METHODS:

A sensitive and specific DNP radioimmunoassay was performed on venous blood samples obtained on post-SAH Days 1, 3, and 7 from 10 consecutive SAH patients (cases) and randomly from 9 healthy volunteers (controls). Clinical and laboratory data, including daily serum sodium concentration and fluid balance, were collected prospectively up to 7 days after the ictus.

RESULTS:

Increase in plasma DNP levels occurred in five (63%) of eight patients who had DNP levels measured on Days 1 and 3 (mean increase, 29%). An increase in DNP level was significantly associated with development of a negative fluid balance (P = 0.003) and hyponatremia (P = 0.008). Three (75%) of the four patients who developed cerebral vasospasm during this study experienced an increase in DNP levels from Days 1 to 3.

CONCLUSION:

The present study is the first to find a significant association between elevated levels of DNP, a new member of the natriuretic peptide family, and the development of diuresis and natriuresis in patients with aneurysmal SAH. Our findings warrant further investigation by means of a large-scale, prospective, case-control study.

Attenuation of cerebral vasospasm in rabbits using clonidine hydrochloride, a central adrenergic agonist

The aim of this study was to assess, firstly, if exclusion of central noradrenergic areas in the hypothalamus and brain stem with the central sympathetic blocker clonidine hydrochloride could prevent the development of chronic vasospasm following experimental subarachnoid haemorrhage in rabbits and, secondly, if, parallel with the effect on cerebral arteries, changes in dopamine beta-hydroxylase concentration in the hypothalamus and brain stem could also be detected. Experimental subarachnoid haemorrhage, in concentrations of 1 ml of autologous arterial blood/1 kg of body weight was carried out on 18 New Zealand rabbits. Histological specimens were obtained by the method of perfusion fixation after the rabbits were sacrificed on day 8 after subarachnoid haemorrhage. The spastic effect of experimentally induced subarachnoid haemorrhage was determined by assessing the intensity of corrugation of the intima of the rabbit basilar artery by the previously developed method of corrugation coefficient and computer image analysis. The concentration and localization of dopamine beta-hydroxylase in noradrenaline-containing neurons was immunohistochemically assessed (semiquantitatively as 0, 1 and 2) with anti-dopamine beta-hydroxylase, at precisely defined sites of the hypothalamus and brain stem of the same rabbit. The results revealed less corrugated and smoother intima in the basilar artery and significantly lower dopamine beta-hydroxylase concentration in the control group of rabbits with sham subarachnoid haemorrhage and without any additional interventions (mean corrugation coefficient=1.123+/-0.024, P=0.35 x 10(-3); mean dopamine beta-hydroxylase=0.350+/-0.071, P=0.22 x 10(-3)), and smoother intima in the basilar artery with significantly lower concentration of dopamine beta-hydroxylase in the clonidine group (rabbits with subarachnoid haemorrhage and central alpha(2)-blocker clonidine hydrochloride at a daily dose of 0.03 mg/kg of body weight for 8 days; mean corrugation coefficient=1.177+/-0.058, P=1.7 x 10(-3); mean dopamine beta-hydroxylase=0.583+/-0.175, P=1.1 x 10(-3)). In comparison, the haemorrhage only group (rabbits with subarachnoid haemorrhage and without medication; mean corrugation coefficient=1.370+/-0.101; mean dopamine beta-hydroxylase=1.214+/-0.313) displayed intensive corrugation of the intima of the basilar artery and a significantly more intensive accumulation of dopamine beta-hydroxylase than did the control group and the clonidine group. The results of this study demonstrated that the central alpha(2)-blocker clonidine hydrochloride effectively prevents vasospasm, and diminishes the concentration of cerebral dopamine beta-hydroxylase in the hypothalamus and brain stem after experimental subarachnoid haemorrhage in rabbits.

Effects of a nitric oxide donor on and correlation of changes in cyclic nucleotide levels with experimental vasospasm

OBJECTIVE

Vasospasm after subarachnoid hemorrhage (SAH) may result from hemoglobin-mediated removal of nitric oxide (NO) from the arterial wall. We tested the ability of the long-acting, water-soluble, NO donor (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-1,2-diolate (DETA/NO), delivered via continuous intracisternal infusion, to prevent vasospasm in a nonhuman primate model of SAH.

METHODS

First, vasorelaxation in response to DETA/NO was characterized in vitro by using monkey basilar artery rings under isometric tension. Next, monkeys were randomized to undergo angiography, unilateral SAH, and no treatment (SAH only, n = 4) or treatment with DETA/NO (1 mmol/L, 12 ml/d, n = 4) or decomposed DETA/NO (at the same dose, n = 4). Vasospasm was assessed by angiography, which was performed on Day 0 and Day 7. Levels of cyclic adenosine monophosphate and cyclic guanosine monophosphate (cGMP) were measured in cerebral arteries on Day 7.

RESULTS

DETA/NO produced significant relaxation of monkey arteries in vitro, which reached a maximum at concentrations of 10(-5) mol/L. In monkeys, angiography demonstrated significant vasospasm of the right intradural cerebral arteries in all three groups, with no significant difference in vasospasm among the groups (P > 0.05, analysis of variance). The ratios of cGMP or cyclic adenosine monophosphate levels in the right and left middle cerebral arteries were not different among the groups (P > 0.05, analysis of variance). There was no significant correlation between arterial cGMP contents and the severity of vasospasm.

CONCLUSION

DETA/NO did not prevent vasospasm. There was no correlation between the severity of vasospasm and cyclic adenosine monophosphate and cGMP levels in the cerebral arteries. These results suggest that events downstream of cyclic nucleotides may be abnormal during vasospasm.

Plasma endothelin and big endothelin concentrations and serum endothelin-converting enzyme activity following aneurysmal subarachnoid hemorrhage

OBJECT

Pathogenesis of delayed ischemia after aneurysmal subarachnoid hemorrhage (SAH) seems to be complex. An important mediator of chronic vasospasm may be endothelin (ET)-1 with its powerful and long-lasting vasoconstricting activity. In this prospective study the author investigated the correlations between serial plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 molar concentration ratio and serum endothelin-converting enzyme (ECE)-1 activity, and ischemic complications after SAH.

METHODS

To measure plasma ET-1 (51 patients), big ET-1 immunoreactivity (22 patients), and serum ECE-1 activity (13 patients), blood samples were obtained on admission, in the morning after aneurysm surgery, and during the 2nd week after hemorrhage in 51 consecutive patients (28 men and 23 women, with a mean age of 50.8 years) with aneurysmal SAH. Mean plasma concentrations of ET-1 in patients with SAH (mean +/- standard deviation: on admission, 4.2 +/- 2 pg/ml; after surgery, 4.3 +/- 2.2 pg/ml; and during the 2nd week after SAH, 3.7 +/- 1.9 pg/ml) differed from those in healthy volunteers (2.9 +/- 1.2 pg/ml; p < 0.01). Plasma concentrations of ET-1 and big ET-1 as well as the ET-1/big ET-1 ratio did not change significantly with elapsed time following SAH; however, serum ECE-1 activity during the 2nd week after SAH was higher in patients with SAH than that in controls (162 +/- 43 compared with 121 +/- 56 pg/ml, respectively; p = 0.028). Plasma ET-1 concentrations (p < 0.05) and the ET-1/big ET-1 ratios (p = 0.063) were higher but plasma big ET-1 concentrations were lower (p < 0.05) in patients who experienced symptomatic delayed cerebral ischemia, compared with other patients with SAH. In addition, in cases in which follow-up computerized tomography scans or magnetic resonance images demonstrated permanent ischemic lesions attributable to vasospasm, patients had higher ET-1 concentrations than did other patients with SAH.

CONCLUSIONS

The plasma ET-1 concentration correlates with delayed cerebral ischemia after SAH, suggesting that an increased ET conversion rate in the endothelium predicts ischemic symptoms. Increased serum ECE-1 activity during the 2nd week may reflect the severity of endothelial injury to cerebral arteries.

Intracisternal sodium nitroprusside fails to prevent vasospasm in nonhuman primates

OBJECTIVE

Hemoglobin contributes to vasospasm after subarachnoid hemorrhage. One mechanism may involve binding of nitric oxide, destruction of nitric oxide, or both. Support for this mechanism would be evidence that nitric oxide donors prevent vasospasm. This study attempted to provide such evidence.

METHODS

A randomized, blinded study was conducted in which 13 monkeys underwent cerebral angiography and creation of a right subarachnoid hemorrhage. Subcutaneous osmotic pumps were implanted to deliver sodium nitroprusside (n = 7) or vehicle (n = 6) via catheters into the right basal cisterns. Seven days later, angiography was repeated, and the animals were humanely killed. Levels of cyclic nucleotides, hemoglobins, and thiocyanate were measured.

RESULTS

Significant vasospasm of the right middle cerebral artery was present in animals treated with sodium nitroprusside (35 +/- 22% reduction in diameter, P < 0.05, paired t test) and placebo (28 +/- 20% reduction, P < 0.05, not significantly different from nitroprusside group by unpaired t test). Adequate delivery of sodium nitroprusside was supported by the finding of a significant increase in cyclic guanosine monophosphate levels in the cerebral arteries of treated animals compared with placebo (P < 0.05, unpaired t test). Thiocyanate was not present in significantly increased amounts in animals treated with nitroprusside, although this group did display elevated concentrations of nitrosyl hemoglobin (measured by electron paramagnetic resonance spectroscopy) and cyanomethemoglobin (measured by spectrophotometry) in the cerebrospinal fluid on Day 7.

CONCLUSION

The lack of effect of sodium nitroprusside was not the result of inadequate drug delivery because cyclic guanosine monophosphate levels were significantly increased in vasospastic arteries. Vasospasm may not have been prevented because of a toxic effect of sodium nitroprusside metabolites, involvement of smooth muscle relaxation or contraction processes downstream of cyclic guanosine monophosphate, or both.

Rise in serum soluble intercellular adhesion molecule—1 levels with vasospasm following aneurysmal subarachnoid hemorrhage

Object. Proinflammatory adhesion molecule expression has been demonstrated to be elevated in patients with aneurysmal subarachnoid hemorrhage (SAH). Recent studies have shown that elevations in soluble intercellular adhesion molecule—1 (ICAM-1) may be predictive of poor outcome in patients with good grade (Hunt and Hess Grades 1–2) aneurysmal SAH at delayed time points that correspond with the risk period for cerebral vasospasm. In addition, ICAM-1 is upregulated in experimental models of vasospasm. Unfortunately, the relationship of adhesion molecule expression to human vasospasm remains unclear. The authors hypothesized that the delayed elevation of soluble ICAM-1 in patients with aneurysmal SAH is associated with the development of cerebral vasospasm.

Methods. Eighty-nine patients with aneurysmal SAH were prospectively enrolled in a study and stratified according to the presence or absence of vasospasm, as evidenced by daily monitoring of transcranial Doppler (TCD) velocities (presence, > 200 cm/second; absence, ≤ 120 cm/second). Levels of soluble ICAM-1 were determined using enzyme-linked immunosorbent assay every other day for 12 days post-SAH. An analysis of covariance model was used to evaluate trends in soluble ICAM-1 levels from 2 days prior to 6 days after the occurrence of documented vasospasm. Two groups of patients, matched for admission admission Hunt and Hess grade, were compared: nine patients with TCD velocities greater than 200 cm/second and nine patients with TCD velocities less than 120 cm/second. From among the patients with TCD velocities greater than 200 cm/second six patients with angiographically documented vasospasm were selected. Patients with TCD velocities less than 120 cm/second and matched admission Hunt and Hess grades but without angiographically documented vasospasm were selected. Patients with TCD-demonstrated vasospasm showed a significant mean rate of rise (p < 0.01) in soluble ICAM-1 levels during the perivasospasm period, but admission Hunt and Hess grade—matched control patients did not (p = not significant [NS]). There was a significant difference between these groups' rates of soluble ICAM increase (p < 0.01). Patients with both TCD- and angiographically demonstrated vasospasm likewise showed a highly significant mean rate of increase in soluble ICAM-1 levels during the perivasospasm period (p < 0.01), whereas admission Hunt and Hess grade—matched controls did not (p = NS). The difference beween these groups' rates of increase was highly significant (p < 0.001).

Conclusions. These data suggest a role for ICAM-1 in the pathophysiology of cerebral vasospasm or its ischemic sequelae. As this relationship is further elucidated, adhesion molecules such as ICAM-1 may provide novel therapeutic targets in the prevention of vasospasm or its ischemic consequences.

Arteriojugular endothelin-1 gradients in aneurysmal subarachnoid haemorrhage

Plasma endothelin (ET) is elevated in patients with vasospasm following subarachnoid haemorrhage (SAH). However, systemic levels provide no indication regarding local production in the brain, and late elevation may be a consequence rather than a cause of vasospasm. We measured arteriojugular (AJ) gradients of ET-1 in 17 patients over the first week after SAH, and related these to the subsequent development of vasospasm. Daily, paired arterial and jugular bulb blood samples were obtained up to seven days post SAH, and assayed for ET-1 using radioimmunoassay. Systemic levels and AJ gradients were compared in patients with and without vasospasm. Significant AJ gradients were observed for ET-1 (P<0.01). These differences remained significant in the subgroup of patients who developed vasospasm (0.12+/-0.05 pmol/l; P<0.05), in whom AJ gradients represented 25+/-7% of systemic levels (0.84+/-0.05 pmol/l). AJ gradients did not reach significance in patients who did not develop vasospasm (0.09+/-0.07 pmol/l; P=0.2). Systemic ET-1 levels and AJ gradients were unrelated to SAH grade, surgical or endovascular interventions, or extracranial complications. AJ gradients in the first week following SAH suggest early production of ET-1 in the cerebrovascular bed. However, early systemic ET-1 levels did not discriminate between patients with and without vasospasm. Larger AJ differences may predict vasospasm, but further work is needed to confirm this observation. AJ gradient measurement may provide a useful technique for investigating the role of other peptides in acute brain injury.

[Von Willebrand factor in patients with subarachnoid hemorrhage]

Von Willebrand factor (vWF) plays an important role in the coagulation system. It affects platelet aggregation in the place of vessel endothelium damage. The importance of vWF in cerebrovascular disease is not clear. The aim of this presentation was to evaluate the vWF level in the plasma and cerebrospinal fluid of patients after subarachnoid hemorrhage including cases with cerebral vasospasm and cerebral infarct. We investigated 66 patients (38 persons graded I-III H&H and 28 persons graded IV H&H). The control group consists of 8 subjects. VWF was measured by ELISA method using standard kit Asserachrom (Boehringer). The vWF level in the plasma reached 288.81 +/- 99.66% (in the control group, 98.84 +/- 14.53%) without significant differences regarding clinical condition of patients. In the cerebrospinal fluid the vWF level was significantly different in I-III H&H patients and in IV H&H patients (1.21 +/- 0.52% and 9.18 +/- 7.58%, respectively, p < 0.001) and in the control group (0.13 +/- 0.33%). Our data indicate that there is correlation (Pearson, p < 0.01) between the level of vWF and neurological condition (GCS) of patients. There is also correlation (p < 0.01) between the level of VWF and the presence of clinical disorders (cerebral vasospasm, delayed neurological deficit (DIND) and cerebral infarct). Based on multivariate analysis, we confirmed that vWF is an independent prognostic factor of cerebral vasospasm (p < 0.01) and ischemic complications (p < 0.02).

CONCLUSIONS

vWF is elevated in the plasma of patients after subarachnoid hemorrhage in early stage of the disease. VWF is present in the cerebrospinal fluid of patients with SAH and its level is higher in patients with poor neurological condition. The VWF elevation in csf is correlated with clinical condition of patients and also the presence of cerebral vasospasm and cerebral infarct. VWF can be used as an independent prognostic factor of cerebral vasospasm and ischemic complications.

Outcome prediction with serum intercellular adhesion molecule-1 levels after aneurysmal subarachnoid hemorrhage

OBJECT

Although upregulated adhesion molecule expression has been demonstrated in experimental models of subarachnoid hemorrhage (SAH) and in the cerebrospinal fluid of patients with aneurysmal SAH, the clinical significance of these proinflammatory findings remains unclear. The authors hypothesize that 1) serum levels of soluble intercellular adhesion molecule-l (ICAM-1) are increased in all patients with aneurysmal SAH shortly after the hemorrhagic event, and 2) elevated soluble ICAM-1 values are associated with poor patient outcome, even when controlling for the severity of the initial hemorrhagic insult.

METHODS

One hundred one patients were prospectively enrolled and stratified according to their admission Hunt and Hess grade and functional status at discharge (modified Rankin Scale [mRS] score). Soluble ICAM-1 levels were determined every other day for 12 days post-SAH by using the enzyme-linked immunosorbent assay. Early soluble ICAM-1 levels (post-SAH Days 2-4) were increased compared with levels in control patients without SAH (p < 0.05). Patients with aneurysmal SAH who had a poor outcome (mRS Grades 4-6) had significantly higher soluble ICAM-1 levels over the first 2 weeks post-SAH compared with patients who had a good outcome (mRS Grades 0-3, p < 0.01). This association with outcome was predicted by late increases (Day 6, p = 0.07; Days 8-12, p < 0.05) rather than early increases (p = not significant) and was best seen in patients with Hunt and Hess Grades I and II. in whom only those with poor outcomes demonstrated delayed ICAM-1 elevations (p < 0.05).

CONCLUSIONS

These data demonstrate a correlation between soluble ICAM-1 levels and functional outcome following aneurysmal SAH that appears to be, at least in part, independent of the initial hemorrhage.

Prevention and reversal of experimental posthemorrhagic vasospasm by the periadventitial administration of nitric oxide from a controlled-release polymer

OBJECTIVE

Despite improvements in the care of patients with aneurysmal subarachnoid hemorrhage, delayed cerebral vasospasm remains a major cause of morbidity and death. There is now evidence that a decrease in the local availability of nitric oxide (NO) plays a role in delayed cerebral vasospasm. We evaluated a controlled-release polymer containing the NO donor (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA/NO) for the treatment of chronic posthemorrhagic vasospasm in the rat femoral artery model.

METHODS

The release kinetics of ethylene/vinyl acetate copolymers loaded with 20% (w/w) DETA/NO were determined in vitro. Chronic vasospasm was induced in the left femoral artery of adult male Fischer 344 rats (n = 35) by exposure to autologous blood. At 1, 3, or 7 days after blood exposure, either a 5-mg polymer loaded with 20% (w/w) DETA/NO or an empty 5-mg polymer was placed in the periadventitial space next to the left femoral artery. At the same time, an empty 5-mg polymer was placed next to the right femoral artery. On the 8th day after blood exposure (at the peak of vasospasm in this model), rats were transcardially perfused with 4% paraformaldehyde, and the left and right femoral arteries were removed for histological processing and morphometric analyses. Vasospasm was expressed as the percent lumen patency of the treated left artery, compared with the control right artery.

RESULTS

The in vitro release kinetics demonstrated that the 20% DETA/NO-loaded polymers released up to 15% of their total drug load during a 9-day period. DETA/NO treatments initiated at 1, 3, or 7 days after blood deposition all significantly inhibited vasospasm, compared with control values (94.6 +/- 7.2% versus 67.6 +/- 5.8%, 104.6 +/- 5.5% versus 64.9 +/- 1.7%, and 102.4 +/- 5.1% versus 73.6 +/- 1.4%, respectively; mean +/- standard error of the mean percent lumen patency; P < 0.001). No adverse effects of treatment were observed.

CONCLUSION

The diazeniumdiolate NO donor DETA/NO can be effectively released from ethylene/vinyl acetate polymers. Administration of DETA/NO into the periadventitial space can prevent the development of chronic posthemorrhagic vasospasm in the rat femoral artery and can reverse established vasospasm. No adverse effects of DETA/NO were observed in this model.

Anticoagulation and induced hypertension after endovascular treatment for ruptured intracranial aneurysms

OBJECTIVE

Guglielmi detachable coil (GDC) embolization may be used to prevent early rebleeding after aneurysmal subarachnoid hemorrhage, but anticoagulation and induced hypertension may increase this risk. We sought to determine retrospectively the relationship between levels of induced hypertension and anticoagulation and incidence of rebleeding in GDC-treated patients.

METHODS

Twenty-five consecutive patients with acute (<14 days) subarachnoid hemorrhage who underwent GDC embolization were retrospectively analyzed with regard to percent obliteration of an aneurysm on postprocedure angiogram, the duration and intensity of anticoagulation, the duration and level of induced hypertension, and the frequency of thromboembolic and rebleeding complications.

RESULTS

Complete angiographic obliteration of the aneurysm was achieved in five cases (20%). In some cases (n = 2), only the dome of the aneurysm was coiled to allow eventual surgical clipping. Heparin was given to 23 patients (92%) for an average of 6 days (range, 8 hrs to 22 days); the mean dose was 588 units/hr, and the mean partial thromboplastin time was 37 secs. Seven patients (28%) were treated with vasopressors for symptomatic vasospasm for a mean duration of 5 days (range, 8 hrs to 9 days); mean arterial blood pressure averaged 118 mm Hg, and peak systolic blood pressures ranged from 195 to 250 mm Hg. There were no episodes of aneurysm rebleeding. Three patients (12%) suffered intraoperative thromboembolic complications, which in one instance was fatal; two of these cases were associated with subtherapeutic partial thromboplastin time values.

CONCLUSION

Induced hypertension (mean arterial blood pressure, 120 mm Hg) and heparinization do not appear to increase the risk of early rebleeding after GDC embolization. In a select group of patients, use of anticoagulation in the immediate perioperative period to prevent thromboembolic complications appears to be safe.

Susac syndrome: a vasospastic disorder?

PURPOSE

The Susac syndrome is a microangiopathy that leads to visual symptoms, hearing loss and neurological symptoms.

CASE REPORT

We report on a young woman suffering from this syndrome who also presented the following signs and symptoms typical of a vasospastic syndrome; 1) a history of cold hands, low blood pressure and migraine; 2) a typical alteration of conjunctival vessels; 3) prolonged flow arrest time after cooling in nailfold capillaromicroscopy; 4) increased resistivity in the orbital vessels measured by color Doppler imaging; and 5) an increased plasma level of endothelin-1.

CONCLUSIONS

We postulate that the Susac syndrome is a manifestation of the vasospastic syndrome.

Inflammatory cytokines in subarachnoid haemorrhage: association with abnormal blood flow velocities in basal cerebral arteries

Subarachnoidal release of inflammatory cytokines (interleukin (IL)-1beta, IL-6, and tumour necrosis factor (TNF)-alpha) was characterised in 35 patients with subarachnoid haemorrhage (SAH) and control subjects and compared with development of complicating haemodynamic abnormalities in basal cerebral arteries and clinical outcome. Serial analysis allowed the observation of a subacute response profile of these key mediators of inflammation in the subarachnoidal space. This compartmentalised inflammatory host response was closely associated in time and extent with development of increased blood flow velocities in the basal cerebral vessels as recorded by transcranial Doppler sonography. Moreover, intrathecal secretion of inflammatory cytokines was significantly increased in patients with poor clinical outcome. Together, these findings suggest a role of excessive compartmentalised inflammatory host response in pathogenesis of cerebrovascular complications after SAH.

Increase and uncoupling of adrenomedullin from the natriuretic peptide system in aneurysmal subarachnoid hemorrhage

OBJECT

Natriuresis is a common systemic manifestation of aneurysmal subarachnoid hemorrhage (SAH). Natriuresis and its accompanying hypovolemia may be a major contributing factor in the pathophysiology of symptomatic cerebral vasospasm.

METHODS

The authors studied 14 consecutive patients with aneurysmal SAH and compared levels of adrenomedullin (ADM), a novel endogenous natriuretic peptide that possesses additional profound vasodilatory properties, with the natriuretic peptide system by using radioimmunoassay. The mean ADM values on admission were 24.8 pg/ml, a twofold increase over control values, but no correlation was found with atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-natriuretic peptide (CNP) from the natriuretic peptide system. At Day 5 post-SAH, ADM levels were significantly elevated in patients with vasospasm documented angiographically or on transcranial Doppler studies as compared with those who suffered no vasospasm (mean 61.9 pg/ml compared with 15.3 pg/ml, p < 0.01).

CONCLUSIONS

The authors conclude that an elevation of ADM in plasma may indicate a physiological regulatory attempt to induce cerebral vasodilation. The regulation of ADM is uncoupled from ANP, BNP, and CNP.

Hemolysate activates P21RAS in rabbit basilar artery

Cerebral vasospasm is the major factor of mortality and morbidity in the patients who have an aneurysmal subarachnoid hemorrhage (SAH). Erythrocyte lysate (hemolysate), oxyhemoglobin (OxyHb), and bloody cerebrospinal fluid (CSF) are the causative agents for vasospasm. However, the signal transduction pathways for the action of these spasmogens are not clear. In this study, we examined the possible effect of these spasmogens on the p21Ras protein, an important factor in the signal cascade, in rabbit basilar artery. Hemolysate enhanced p21Ras precipitation over a 7-day period. The initial increase of p21Ras precipitation occurred after the tissues were incubated for 2 days with hemolysate. The peak effect of hemolysate, which was markedly increased compared with control (P<0.05, ANOVA), was observed on day 3. OxyHb and blood CSF, in contrast, failed to produce consistent or marked changes in p21Ras precipitation. p21Ras inhibitors FTPase inhibitor 1 and manumycin abolished hemolysate-induced enhancement of p21Ras immunoprecipitation. Genistein, a tyrosine kinase inhibitor, failed to reduce the effect of hemolysate on p21Ras. We concluded that hemolysate activates p21Ras in the rabbit basilar artery.

Effect of endothelin receptor antagonists on non-muscle matrix compaction in a cell culture vasospasm model

Endothelin-1 (ET-1), a potent vascular smooth muscle constrictor, is one of the possible spasmogens in cerebral vasospasm. However, the role of ET-1 in non-muscle compaction (another aspect of the pathogenesis of cerebral vasospasm) has not been reported. This study was undertaken to demonstrate the effect of ET-1, as well as erythrocyte lysate and bloody cerebrospinal fluid (CSF), on fibroblast populated collagen lattice (FPCL) compaction. Human dermal fibroblasts were used to form FPCL. The concentration-dependent effect of ET-1 was examined in the absence and presence of an ETA receptor antagonist (BQ-485), or an ETB receptor antagonist (BQ-788), or both. FPCL compaction was determined by measuring reduction of areas over five days following treatment. To compare the effect of ET-1 on lattice compaction, erythrocyte lysate and bloody CSF obtained from a cerebral vasospasm patient were also tested. We found that ET-1 increased FPCL compaction in a concentration-dependent (but not time-dependent) manner. Erythrocyte lysate produced the strongest compaction, however, without time-dependence. Bloody CSF promoted FPCL compaction in a time-dependent fashion. Compaction induced by ET-1 was inhibited by BQ-485 but not by BQ-788. We concluded that ET-1 promotes FPCL compaction by activation of ETA receptors. Other components in bloody CSF or erythrocytes may also contribute to FPCL compaction.

Plasma endothelin concentrations after aneurysmal subarachnoid hemorrhage

OBJECT

The pathogenesis of cerebral vasospasm and delayed ischemia after subarachnoid hemorrhage (SAH) seems to be complex. An important mediator of chronic vasospasm may be endothelin (ET), with its powerful and long-lasting vasoconstricting activity. In this study the author investigated the correlation between serial plasma concentrations of ET and ischemic symptoms, angiographically demonstrated evidence of vasospasm, and computerized tomography (CT) findings after aneurysmal SAH.

METHODS

Endothelin-1 immunoreactivity in plasma was studied in 70 patients with aneurysmal SAH and in 25 healthy volunteers by using a double-antibody sandwich-enzyme immunoassay (immunometric) technique. On the whole, mean plasma ET concentrations in patients with SAH (mean +/- standard error of mean, 2.1 +/- 0.1 pg/ml) did not differ from those of healthy volunteers (1.9 +/- 0.2 pg/ml). Endothelin concentrations were significantly higher (p < 0.05) in patients who experienced delayed cerebral ischemia with fixed neurological deficits compared with those in other patients (post-SAH Days 0-5, 3.1 +/- 0.8 pg/ml compared with 2.1 +/- 0.2 pg/ml; post-SAH Days 6-14, 2.5 +/- 0.4 pg/ml compared with 1.9 +/- 0.2 pg/ml). Patients with angiographic evidence of severe vasospasm also had significantly (p < 0.05) elevated ET concentrations (post-SAH Days 0-5, 3.2 +/- 0.8 pg/ml; post-SAH Days 6-14, 2.7 +/- 0.5 pg/ml) as did those with a cerebral infarction larger than a lacuna on the follow-up CT scan (post-SAH Days 0-5, 3.1 +/- 0.8 pg/ml; post-SAH Days 6-14, 2.5 +/- 0.4 pg/ml) compared with other patients. Patients in whom angiography revealed diffuse moderate-to-severe vasospasm had significantly (p < 0.05) higher ET levels than other patients within 24 hours before or after angiography (2.6 +/- 0.3 compared with 1.9 +/- 0.2 pg/ml). In addition, patients with a history of hypertension or cigarette smoking experienced cerebral infarctions significantly more often than other patients, although angiography did not demonstrate severe or diffuse vasospasm more often in these patients than in others.

CONCLUSIONS

Endothelin concentrations seem to correlate with delayed cerebral ischemia and vasospasm after SAH. The highest levels of ET are predictive of the symptoms of cerebral ischemia and vasospasm, and ET may also worsen ischemia in patients with a history of hypertension. Thus, ET may be an important causal or contributing factor to vasospasm, but its significance in the pathogenesis of vasospasm remains unknown.

[Monitoring jugular venous oxygen saturation in severe cerebral vasospasm after subarachnoid hemorrhage]

Cerebral arterial vasospasm is a major complication of aneurysmal subarachnoid haemorrhage. The conventional treatment of this complication includes haemodilution, hypervolaemia, arterial hypertension and nimodipine. Some patients do not respond to this therapy and require an intraarterial infusion of papaverine and/or a cerebral angioplasty. Transcranial Doppler detects cerebral vasospasm. However it does not provide an accurate metabolic information on the ischaemic status of the cerebral tissue. This article describes the monitoring of jugular venous bulb oxygen saturation to obtain a real time information on the metabolic effect of cerebral vasospasm and its variations after intra-arterial infusion of papaverine.

[Subarachnoid hemorrhage, cerebral ischemia and endothelin-1]

INTRODUCTION

Cerebral vasospasm is involved in the development of delayed ischemic lesions in patients with subarachnoid hemorrhage. We developed an integral theoretical model to explain the pathophysiology of cerebral vasospasm, in which endothelin-1 has a pivotal role in the development of both cerebral vasospasm and delayed ischemic neurological deficits (DIND).

OBJECTIVE

The objective of this study is to analyze the relationship between temporal profile of plasma endothelin-1 levels and the development of cerebral vasospasm and DIND.

PATIENTS AND METHODS

We analyzed sequentially plasma endothelin-1 levels in 17 patients with aneurysmatic subarachnoid hemorrhage. All the patients had complete clinical and neuroradiological studies. Patients were classified according to Fisher's score.

RESULTS

Patients (4 males and 13 females, aged 48.1 +/- 20.3 years) had a good clinical condition (Hunt-Hess < 4, GCS > 10). Two weeks after bleeding, patients had higher plasma endothelin-1 levels than healthy volunteers (p = 0.024). Patients who developed DIND had higher plasma endothelin-1 levels (p = 0.034) and a different evolution (p = 0.0146) than patients without DIND. There is a significant correlation (p = 0.02) between basal plasma endothelin-1 levels and GOS score. Multiple regression analysis shows a significant dependence between plasma endothelin-1 levels and Fisher's score (p = 0.0195), development of DIND (p = 0.0095), and GOS score (p = 0.0319). Logistic regression analysis finds a predictive relation between Fisher's score and plasma endothelin-1 levels for the development of DIND (overall predicted = 74.24%; p = 0.0148).

CONCLUSIONS

Plasma endothelin-1 levels are increased in patients after subarachnoid hemorrhage and are associated with the development of cerebral vasospasm and DIND.