A modified compression model of spinal cord injury in rats: functional assessment and the expression of nitric oxide synthases.

STUDY DESIGN: Experimental study. OBJECTIVES: To investigate a modified compression model of spinal cord injury (SCI) in adult rats by using a room-air- inflated Fogarty balloon catheter. SETTING: Kaohsiung, Taiwan. METHODS: The rats were divided into injury, sham-operated and control groups. A 2-French Fogarty catheter was passed from the lumbar spine (L3-L4) epidurally, with a mini-laminectomy under the microscope, to the level of thoracic spine (T6-T7). The actual site of the catheter tip was confirmed with X-ray. The balloon of Fogarty catheter then was inflated with room air, 0.2 ml, for 10 min. Mini-laminectomy was performed without inserting the catheter in the sham-operated group. Quantitative neurological outcomes were evaluated with the Basso, Beattie and Bresnahan (BBB) locomotor rating scale daily. The gene expression of nitric oxide synthases (NOSs) of the spinal cord was investigated at the end of the functional assessment. RESULTS: The mean BBB locomotor scores were 10±1.85 and 10±1.85, respectively, on days 1 and 3 in the injury group, and 21 and 20.29±0.69, respectively, in the sham-operated group. There was a significantly increased gene expression of inducible NOS in the SCI group compared with the sham-operated group and control group. Endothelial NOS gene expression was not significantly different among the groups. CONCLUSION: The functional and molecular assessments show that this modified balloon-compression technique is a reproducible, simple and inexpensive model of SCI in rats.

Effect of silencing HIF-1α on proliferation, invasion and migration of glioblastoma U87 cells.

The objective of the study was to evaluate the effect of silencing hypoxia-inducible factor 1α (HIF-1α) on proliferation, invasion, and migration of glioblastoma U87 cells. HIF-1α-shRNA lentiviral vector was designed for liposome-mediated transfection into U87 cells. The efficiency of interference was assessed by RT-PCR and Western blot. Cell proliferation was measured by MTT assay. Cell migration was observed by the migration test. The capabilities of invasion and migration were detected using the Transwell model. The research involved experiments in the interference group (shRNA transfected), the control interference group (empty vector transfected), and the untreated (non-transfected) group. Compared with the control interference group and the untreated group, the expressions of HIF-1α mRNA and protein were significantly down-regulated, and the proliferation and invasion of U87 cells were significantly inhibited in the interference group. HIF-1α mRNA and protein are effectively suppressed by HIF-1α-shRNA in U87 cells, which appears to inhibit proliferation, invasion, and migration of U87 cells.

Epidermoid cysts associated with thoracic meningocele.

Intraspinal tumours of cutaneous origin associated with various spinal dysraphisms have been well documented in the literature. However, the metachronous development of intra- and extra-medullary tumours in conjunction with dorsal meningocele is rare. The authors report a patient with a thoracic dorsal meningocele and congenital intradural extramedullary epidermoid tumour. The patient developed an intramedullary epidermoid growth 12 years later. Subtotal resection of the tumour predisposed to a later recurrence. Meningocele is not always an isolated clinical entity but the concurrent occult lesions are usually veiled by the more conspicuous surface anomaly. Thorough magnetic resonance imaging of the whole neural axis helps to identify associated pathologies. Delicate intradural exploration by a microsurgical approach is necessary to achieve appropriate treatment.

The effect of an adenosine A1 receptor agonist in the treatment of experimental subarachnoid hemorrhage-induced cerebrovasospasm.

BACKGROUND: Adenosine is a potent vasodilator and an important modulator of cardiovascular function. It has been postulated that nitric oxide (NO) is involved in adenosine-induced vasodilation. This study was designed to examine the effect of an adenosine A1 agonist, N6-cyclopentyladenosine (CPA), in the prevention of subarachnoid haemorrhage (SAH)-induced vasospasm. Method. Experimental SAH was induced in Sprague-Dawley rats by injecting 0.3 mL autogenous blood into the cisterna magna. Intraperitoneal injections of CPA (0.003 mg/kg), or vehicle were administered 5 min and 24 hours after induction of SAH. The degree of vasospasm was determined by averaging the cross sectional areas of the basilar artery 2 days after SAH. Expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in basilar artery were evaluated. Findings. There were no significant differences among the control and treated groups in physiological parameters recorded before sacrifice. When compared with animals in the control group, cross-sectional area of basilar arteries areas in the SAH only, SAH plus vehicle and SAH plus CPA groups were reduced by 19% (p < 0.01), 22% (p < 0.01), and 9% (p = 0.133), respectively. The cross-sectional areas of the CPA-treated group differed significantly from those of the SAH only and SAH plus vehicle group (p < 0.05). Induction of iNOS-mRNA and protein in basilar artery by SAH was not significantly diminished by CPA. The SAH-induced suppression of eNOS-mRNA and protein were relieved by CPA treatment. Conclusions. This is the first evidence to show an adenosine A1 receptor agonist is effective in partially preventing SAH-induced vasospasm without significant cardiovascular complications. The mechanisms of adenosine A1 receptor agonists in attenuating SAH-induced vasospasm may be, in part, related to preserve the normal eNOS expression after SAH. Inability in reversing the increased iNOS expression after SAH may lead to the incomplete anti-spastic effect of CPA.

Simultaneous multiple hypertensive intracerebral haemorrhages.

BACKGROUND: Simultaneous occurrence of multiple intracerebral haemorrhages (ICHs) in different arterial territories is a rare clinical event which has been reported to be associated with cerebral amyloid angiopathy, venous sinus thrombosis, coagulopathy, vasculitis, haemorrhagic transformation of cerebral infarcts and multiple intracranial pathologies such as vascular anomalies or tumours. Although hypertension is the most common etiological factor for the development of spontaneous single intracerebral bleeding, its role in simultaneous multiple ICHs is not clear. METHODS: The authors have reviewed all patients with non-traumatic ICH admitted to Kaohsiung Medical University Hospital from 1993 to 2002. Ten hypertensive patients with simultaneous multiple ICHs were found. For the purpose of comparison, another 600 cases with solitary hypertensive ICH were also reviewed as a control group. Computerized tomographic scans and medical records concerning patients' histories, clinical presentations, locations of haematomas, associated risk factors, and outcome were analyzed. FINDINGS: The mean age and sex distribution were similar in both patient groups. Bilateral putaminal or thalamic haemorrhages were the most common combinations of simultaneous bleedings. As for the individual location of haematoma, there was a strong preponderance for the supratentorial space with the thalamus being the most preferable site. The duration of hypertension was longer and the percentage of previous stroke was higher in patients with multiple ICHs. Other associated risk factors were similar in both groups except for higher incidence of hypercholesterolemia in multiple ICHs group. Patients with simultaneous multiple ICHs had a much worse outcome compared to those with solitary ICH. CONCLUSIONS: As with solitary ICH, hypertension is still the most important etiological factor for simultaneous multiple ICHs. The widespread and prolonged degeneration of intracerebral arterioles predispose patients to the development of multiple ICHs, which could be justified by the longer history of hypertension and higher incidence of former strokes. Only hypercholesterolemia was identified to be significantly associated with this unusual brain event in our study. The mechanism underlying the development of simultaneous multiple ICHs is not clear although structural and haemodynamic changes of first haemorrhage may be responsible for the second one. Poorer outcome in patients with multiple ICHs can be explained by the concomitant destruction of crossing and non-crossing fiber tracts and bilateral diaschisis phenomenon.

Alteration of ischemic reperfusion injury in the rat neocortex by a potent antioxidant mexiletine.

The mechanisms by which mexiletine exerts its effects in increasing myocardial circulation, and smooth muscle perfusion and alleviating diabetic neuropathic pain have been widely discussed. The purpose of this study was to examine the protective effect of this compound in ischemia/reperfusion-induced cerebral injury following middle cerebral artery occlusion in Sprague-Dawley rats. Blood flow to the left cerebral hemisphere of the animals was interrupted by occluding the left cerebral artery and both carotid arteries simultaneously for 3 hrs. These animals were assigned to one of ten groups and divided into treatment group and pretreatment group; 1) control treatment group (n=8); 2) vehicle treatment group (n=8); 3) lower dose mexiletine (400 microg/kg) treatment group (n=8); 4) medium dose mexiletine (800 microg/kg) treatment group (n=8); 5) high dose mexiletine (2 mg/kg) treatment group (n=8); 6) control pretreatment group (n=8); 7) vehicle pretreatment group (n=8); 8) lower dose mexiletine (400 microg/kg) pretreatment group (n=8); 9) medium dose mexiletine (800 microg/kg) pretreatment group (n=8); and 10) high dose mexiletine (2 mg/kg) pretreatment group (n=8). The volume of cerebral infarction was measured in serial brain sections stained with triphenyltetrazolium chloride (TTC). Tissue infarction volume and tissue edema were estimated for each animal. The volume of cerebral infarction was significantly decreased in rats pretreated with mexiletine, and the ratio of tissue edema was also decreased as the dose of mexiletine increased. These results demonstrate that mexiletine, an anti-arrhythmic and use-dependent Na+ channel blocker, has protective effects in stroke at concentrations sufficient to confer significant protection, as measured by the volume of infarction and brain edema index in a model of focal, neocortical ischemia in Sprague-Dawley rats.

Continuous intravenous infusion of CGS 26303, an endothelin-converting enzyme inhibitor, prevents and reverses cerebral vasospasm after experimental subarachnoid hemorrhage.

OBJECTIVE: Endothelin-mediated vasoconstriction has been implicated in the pathophysiology of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). Endothelin-1, the most potent vasoconstrictor peptide of the endothelin family, is synthesized initially as a large prepropeptide that requires multiple steps of post-translational processing for activation. The final step of this processing involves the proteolytic cleavage of a relatively inactive precursor, big endothelin-1, by the metalloprotease endothelin-converting enzyme. Previous findings have demonstrated that intravenous bolus injections of an endothelin-converting enzyme inhibitor (CGS 26303) administered twice daily can prevent and reverse arterial narrowing in a rabbit model of SAH. However, attenuation of vasospastic response was incomplete and required relatively high doses to be effective in reversing vasospasm. Therefore, the present study evaluated an alternative protocol for administration of CGS 26303 to optimize the antispastic influence of this compound. METHODS: Continuous intravenous infusion of CGS 26303 at doses of 2.4, 8.0, or 24.0 mg/kg/d was initiated either 1 hour (prevention paradigm) or 24 hours (reversal paradigm) after experimental SAH in New Zealand White rabbits. All animals were killed by perfusion-fixation 48 hours after SAH. Basilar arteries were then removed and sectioned, and their cross-sectional areas were measured by use of computer-assisted video microscopy. RESULTS: Continuous intravenous infusion of CGS 26303 attenuated SAH-induced cerebral vasospasm in a dose-dependent manner in both the prevention and the reversal groups. These effects achieved statistical significance at all doses as compared with the SAH-only or SAH-plus-vehicle groups. Furthermore, the attenuation of vasospasm after continuous infusion of CGS 26303 was more efficacious than that obtained with bolus injections. CONCLUSION: These findings provide further support for the use of endothelin-converting enzyme inhibition as a therapeutic strategy for reduction of cerebral vasospasm, and they also support the effectiveness of this strategy even when initiated after arterial narrowing has been established. The findings also indicate that continuous intravenous infusion of CGS 26303 is a more effective approach for attenuation of vasospasm than bolus intravenous administration.

Prevention of cerebral vasospasm by a capsaicin derivative, glyceryl nonivamide, in an experimental model of subarachnoid hemorrhage.

BACKGROUND: Cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) remains a major complication in patients suffering from SAH. In our previous study, we reported that stimulating vascular K(+) channel activity prevented the development of cerebral vasospasm. Recent evidence indicates that glyceryl nonivamide (GLNVA), a capsaicin derivative, has a vasorelaxant effect on the aortic vascular smooth muscle due to the release of coronary calcitonin gene-related peptide, which in turn stimulates K(+) channel opening. The purpose of the present study was to examine the preventive effects of GLNVA on vasospasm. METHODS: New Zealand white rabbits were subjected to experimental SAH by injecting autologous blood into the cisterna magna. GLNVA or vehicle was injected intrathecally immediately after the induction of SAH. All animals were killed by perfusion-fixation at 48 hours after SAH. The basilar arteries were removed and sectioned, and their cross-sectional areas were measured. RESULTS: The average cross-sectional areas of basilar arteries were reduced by 69% and 71% in the SAH only and SAH plus vehicle groups, respectively, when compared with the healthy controls. After treatment with 0.35, 1.75, and 3.5 mg/kg GLNVA in rabbits subjected to SAH the average cross-sectional area was decreased by 46%, 12% and 2%, respectively, when compared with the healthy controls. The protective effect of GLNVA achieved statistical significance at all dosages. Morphologically, corrugation of the internal elastic lamina of vessels was often observed in the vehicle-treated group, but was not prominent in the GLNVA-treated groups or healthy controls. CONCLUSION: The findings showed that GLNVA dose-dependently attenuated cerebral vasospasm after SAH in the rabbit. These results suggest that intrathecal administration of GLNVA could be an effective strategy for preventing cerebral vasospasm after SAH.

[Risk of convulsions due to the use of bupropion as an aid for smoking cessation]. / Risico van convulsies bij gebruik van bupropion als hulpmiddel bij het stoppen met roken.

Bupropion is a new aid in smoking cessation. Since marketing of this product in the Netherlands (from December 1999 on), 7 cases of (possible) convulsions have been reported. In 3 cases there was a contraindication in the form of a history of epilepsy. The four other cases concerned tonic-clonic epileptic seizures in patients with no history of epilepsy and no combination with other medication. In view of the seriousness of this, already known, side effect of bupropion, physicians ought to be sensitive to situations with increased risk of this side effect. In addition it is advised to explain to the patient the proper use of bupropion, which is not comparable to nicotine chewing gum and should be swallowed whole due to the slow release properties of the tablet.

Effects of endothelin-converting enzyme inhibitors on hemolysate-induced morphological changes and production of endothelin-1 in bovine cerebrovascular endothelial cells.

The effects of CGS 26303, a dual inhibitor of endothelin-converting enzyme (ECE) and neutral endopeptidase 24.11, and its prodrug, CGS 26393, on bovine cerebrovascular endothelial cells stimulated with hemolysate were investigated. Upon incubation with hemolysate for 48 h, cell density was significantly decreased, with concomitant increases in endothelin-1 (ET-1) (42 vs 11 pg/ml) and big ET-1 (79 vs 27 pg/ml) levels in culture medium when compared with controls. Simultaneous addition of CGS 26303 (10 and 100 microM) and hemolysate protected against cell loss and decreased cellular vacuolization caused by hemolysate. The levels of ET-1 and big ET-1 in the culture medium were decreased dose-dependently. More drastically, pretreatment with 100 microM CGS 26303 for 30 min decreased the production of ET-1 and big ET-1 by 94% and 87%, respectively, when compared with the untreated control. However, treatment with CGS 26393 was much less effective. These results suggest that suppression of ET-1 production by ECE inhibitors may prove to be efficacious for the treatment of hemolysate-induced cytotoxicity on cerebral endothelial cells.

Systemic administration of mexiletine for attenuation of cerebral vasospasm following experimental subarachnoid haemorrhage.

Mexiletine is a class Ib drug that is widely used to treat ventricular arrhythmias. This compound is mainly known as a sodium channel blocker, but studies have demonstrated that it can also activate ATP-sensitive K+ channels and block Ca2+ channels. Recent in vitro data from experiments on liposomes indicate that mexiletine is also a potent antioxidant. The unique activity profile of this drug raised the possibility that it might be of benefit in limiting cerebral vasospasm. Our first series of experiments assessed the effects of mexiletine on transclivally exposed rabbit basilar arteries. The arteries were treated with 50-mM KCl, 20-nM endothelin-1 (ET-1), or 100-microM lysophosphatidic acid (LPA) in the presence or absence of 400-mM mexiletine. Vasoconstriction caused by KCl, ET-1, and LPA was inhibited by mexiletine. In a second series of experiments, subarachnoid haemorrhage (SAH) was induced in rabbits by injecting 3-ml of autologous arterial blood into the cisterna magna. Forty-eight hours after SAH induction, transclivally exposed basilar arteries exhibited a spastic constriction that was partially reversed by topical application of 400-microM mexiletine. In a third set of experiments, mexiletine was administered orally at dosages of 80-, 20, and 5-mg/kg/day t.i.d., beginning 3 hours before SAH to study the prevention of vasospasm. In a separate group of animals, 80- and 20-mg/kg/day t.i.d. of mexiletine was administered 21 hours post-SAH induction, to study the reversal of vasoconstriction. Microscopic analysis of vessels from controls (no SAH), SAH-only, and SAH + mexiletine groups indicated there was 71.43% vascular constriction in the SAH-only group compared with controls. Considerable vasorelaxation was seen in the prevention study, in which average arterial cross-sectional areas were reduced by only 17.86% and 39.29% in the mexiletine 80- and 20-mg/kg/day groups, respectively, compared with controls (p < 0.001). Compared with controls, average arterial cross-sectional areas were reduced by 53.58% and 64.29% in the mexiletine 80- and 20-mg/kg/day reversal groups, respectively. Our findings indicate that mexiletine induces potent relaxation in cerebrovascular arteries contracted with various agents, and that it prevents and partially reverses SAH-induced vasoconstriction.

Delayed administration of the K+ channel activator cromakalim attenuates cerebral vasospasm after experimental subarachnoid hemorrhage.

BACKGROUND: Delayed cerebral vasospasm remains an unpredictable and inadequately treated complication of aneurysmal subarachnoid hemorrhage (SAH). Recent evidence indicates that the potassium channel activator cromakalim is capable of limiting cerebral vasospasm in rabbits when administered immediately after experimental SAH (i.e. before spastic constriction has been initiated). However, the ultimate clinical value of cromakalim for treating vasospasm will depend in part on its effectiveness when administered after SAH-induced constriction has already been initiated. The present study examined the effects of cromakalim on vasospasm when treatment was initiated after SAH-induced constriction was underway. METHODS: New Zealand white rabbits were subjected to experimental SAH by injecting autologous blood into the cisterna magna. Cromakalim (0.03, 0.1 or 0.3 mg/kg) or vehicle was injected intravenously at 8 hour intervals beginning 24 hours post-SAH. Animals were killed by perfusion fixation 48 hours after SAH. Basilar arteries were removed and sectioned, and cross-sectional area was measured. FINDINGS: The average cross sectional areas of basilar arteries were reduced by 64% and 68% in the SAH-only and SAH + vehicle groups, respectively. Treatment with cromakalim dose-dependently attenuated SAH-induced constriction. The groups treated with 0.03, 0. 1, and 0.3 mg/kg cromakalim exhibited average decreases in cross-sectional area of 57%, 42%, and 19%, respectively. INTERPRETATION: These findings indicate that cromakalim dose-dependently attenuates cerebral vasospasm when administered 24 hours after experimental SAH in the rabbit. The results suggest K(ATP) channel activators, such as cromakalim. could be of benefit for reversing cerebral vasospasm after aneurysmal SAH.

Prognosis of spontaneous intracerebral hemorrhage in hemodialysis patients.

During an 8-year period, 32 consecutive patients with chronic renal failure on maintenance hemodialysis were diagnosed to have cerebral hemorrhage. The outcome was determined using the activity of daily life (ADL) at 6 months after hemorrhage. The overall mortality was 64%. Of the 12 surviving patients, no one made a good recovery (back to normality), 5 recovered to ADL grade II, 4 to grade III, 1 to grade IV, and 2 to grade V. Up to 91% of the patients had a history of hypertension. On admission, Glasgow coma scale (GCS) was 15 in 8 cases, 8-14 in 10, and below 8 in 14. The poor prognostic factors showing statistical significance included a poor admission GCS, age above 65 years, and blood sugar level of more than 200 mg/dl. Other factors which apparently were not related to the outcome included sex, history of stroke, acute myocardial infarction, hypertension, and diabetes mellitus, the locations of hemorrhage, the duration of hemodialysis, treatment modality (surgery vs non-surgery), and the laboratory data (blood urea nitrogen, creatinine, platelet count, hemoglobin, prothromin time, and partial thromboplastin time). This study confirmed a poor prognosis for hemodialysis patients with cerebral hemorrhage. More attention should be paid to the control of blood sugar in this group to improve the outcome of cerebral hemorrhage in hemodialysis patients, especially in elderly patients with poor admission GCS.

Attenuation of basilar artery spasm after experimental subarachnoid hemorrhage in rabbit by potassium channel activator cromakalim--a preliminary result.

Cerebral vasospasm associated with aneurysmal subarachnoid hemorrhage (SAH) remains a major complication in patients suffering from SAH. Regulation of membrane potential of arterial smooth muscle through activation or inhibition of potassium (K+) channel activity provides an important mechanism to dilate or constrict arteries. The present study examined the effect of a K+ channel activator, cromakalim, on cerebral vasospasm following experimental SAH. By the route of topical application and intra-arterial injection, basilar arteries were exposed transclivally and measured on-line using videomicroscopic camera. Continuous microinjection from right vertebral artery was given after the result of application was observed. Basilar artery spasm induced by SAH was released by topical or intra-arterial administration of cromakalim, and this beneficial effect against cerebral vasospasm was dose-dependent. There was no significant difference between topical and intra-arterial administration of cromakalim. These results indicate that K+ channel activator may play an important role for ameliorating cerebral vasospasm. An important goal of future studies will be to carefully evaluate the possibility and effect of intra-arterial administration of cromakalim to treat angiographic vasospasm.

Acute hydrocephalus and chronic hydrocephalus with the need of postoperative shunting after aneurysmal subarachnoid hemorrhage.

During a 6-year period, 168 consecutive patients who presented with subarachnoid hemorrhage (SAH) and underwent surgical clipping of aneurysms were reviewed at a follow-up examination from 6 to 77 months (mean 38 months) after the ictus. Acute hydrocephalus was defined when the bicaudate index was greater than the 95th percentile for age on a computed tomographic scan within 72 hours of the hemorrhage. Forty (24%) patients developed acute hydrocephalus. The Hunt and Hess grades and Fisher's SAH grades at the time of admission, the presence of intraventricular hemorrhage and symptomatic cerebral vasospasm, and cerebrospinal fluid (CSF) diversion were found to be significantly associated with acute hydrocephalus. The overall mortality in this study was 16%. Of the 141 surviving patients, 20 (14%) patients underwent ventriculoperitoneal (VP) shunt replacement secondary to chronic hydrocephalus. In the present study, we found that the following factors were significantly related to the need of VP shunting: increasing age, the presence of acute hydrocephalus, preoperative CSF diversion, low admission Hunt and Hess grades, and poor Fisher's SAH grades. No patient was readmitted for shunt replacement at our hospital later than 117 days after hemorrhage. Acute hydrocephalus was combined with high mortality (28%) at our follow-up review. Ten of 29 (34%) patients with acute hydrocephalus required definite shunt replacement. However, less than 10% of patients without acute hydrocephalus needed shunting postoperatively. We recommend that patients with aneurysmal SAH should be followed up at least 6 months after the hemorrhage, especially in those patients with high risks of developing chronic hydrocephalus.

Spontaneous intracerebral hemorrhage in children.

We reviewed our experience in 42 children younger than 16 years with spontaneous intracerebral hemorrhage (ICH) treated between January 1989 and December 1997. Glasgow coma scale (GCS) on admission was 15 in 21 (50%) patients. The most frequent presenting symptoms were headache in 28 (67%) patients, followed by loss of consciousness in 22 (52%) patients and vomiting in 21 (50%) patients. Three cases were diagnosed initially as meningitis and two cases as common cold. The locations of ICH were lobar (26 patients) and cerebellar (7). Cerebral angiographies were performed on 28 patients, and were diagnostic in 19 (68%). Magnetic resonance imaging (MRI) scans revealed two cases of cavernous angiomas, which were confirmed by the pathologic studies of surgical specimens. Laboratory examinations detected two cases of acute leukemia. Four categories of the causes of ICH were determined in 23 (55%) patients. The leading cause of bleeding was arteriovenous malformations (AVMs). The in-hospital survival rate of all patients in this study was 79%. Patients with GCS 3-5 on admission and ICH located at brain stem, cerebellum, and multiple subcortical areas had higher mortality rates. On the follow-up (mean 42 months), seventy percent of our cases had made a good recovery, 21% a fair recovery, 3% a poor recovery, and 6% had died. Children with ICH recover motor function more rapidly than adults. However, visual deficits always persist at our long-term follow-up examinations. A physician should keep in mind the diagnosis of ICH in children, even though the presenting symptoms may be non-specific and the incidence of ICH is very low in children.

Outcome of spontaneous subarachnoid hemorrhage of unknown etiology.

During a 7-year period, 56 patients with a verified subarachnoid hemorrhage (SAH) in whom neuroradiological investigations failed to reveal a reasonable cause of the bleeding were evaluated. Forty-six patients who survived the SAH were interviewed at a follow-up examination from 10 to 82 months (mean 37 months) after the bleeding. Early prognosis of an unfavorable outcome was possible on the basis of two clinical variables: the poor Glasgow coma scale (GCS < = 11) at admission and the Fisher's SAH grade of greater than II on brain computerized tomographic scans. Other clinical variables in the acute stage, including age, sex, a history of hypertension and the complications of SAH, such as vasospasm, hydrocephalus, and rebleeding, were not related to the early outcome. GCS on discharge was predictive of activity of daily life at follow-up review. On the follow-up, 80% of the patients experienced a good recovery. Rebleeding episode occurred in a patient 5 years after the bleeding. The overall rebleeding rate was 2.2% (equivalent to an annual recurrence of 0.7%). This study confirmed a good prognosis for patients with SAH of unknown cause. We recommend that after thorough panangiography, those patients with SAH of unknown etiology should be encouraged to return to a normal life style without any restriction.

Surgical outcome of anterior communicating artery aneurysms.

During a 6-year period, 65 consecutive patients who had undergone anterior communicating artery aneurysmal surgery were reviewed at a follow-up examination from 6 to 78 months (mean 35 months) after operation. On admission 69% of cases had a good Hunt and Hess scale (grades I to II) and 31% a poor grade (grades III to V). The degree of subarachnoid hemorrhage (SAH) was determined by Fisher's grade. Sixteen (25%) patients were classified in grades I and II. Forty-six percent of cases had pre-existing hypertension. Early surgery (within the first three days after the bleeding) was performed in 17% of cases. Intraoperative rupture of aneurysm occurred in six (9.2%) patients. Symptomatic cerebral vasospasm was diagnosed in 14 (22%) cases, but only 8 (12%) had evidence of low density on the computerized tomographic scan. Hydrocephalus developed in 16 (25%) cases and 10 needed ventriculoperitoneal shunting. The outcome was determined using the activity of daily life. Sixty-five percent of the patients made a good recovery and 13.8% died. The significant poor prognostic factors included a poor pre-operative grade of the Hunt and Hess scale, the presence of symptomatic cerebral vasospasm, and the Fisher's SAH grade of greater than II. Other factors which apparently were not related to the outcome included age, sex, timing of surgery, history of hypertension, intraoperative rupture, and the development of hydrocephalus.

Monoclonal antibodies against ICAM-1 and CD18 attenuate cerebral vasospasm after experimental subarachnoid hemorrhage in rabbits.

BACKGROUND AND PURPOSE: Inflammatory responses have been implicated in the elaboration of several forms of central nervous system injury, including cerebral vasospasm after subarachnoid hemorrhage (SAH). A critical event participating in such responses is the recruitment of circulating leukocytes into the inflammatory site. Two of the key adhesion molecules responsible for the attachment of leukocytes to endothelial cells are intercellular adhesion molecule-1 (ICAM-1) and the common beta chain of the integrin superfamily (CD18). This study examined the effects of monoclonal antibodies on ICAM-1 and the effects of CD18 on cerebral vasospasm after SAH. METHODS: A rabbit model of SAH was utilized to test the influence of intracisternally administered antibodies to ICAM-1 and CD18 on cerebral vasospasm. Antibodies were administered alone or in combination, and the cross-sectional area of basilar arteries was assessed histologically on day 2 post-SAH. RESULTS: Treatment with antibodies to ICAM-1 or CD18 inhibited vasospasm by 22% and 27%, respectively. When administered together, the attenuation of vasospasm increased to 56%. All of these effects achieved statistical significance. CONCLUSIONS: These findings provide the first evidence that the severity of cerebral vasospasm can be attenuated using monoclonal antibodies against ICAM-1 and CD18. The results reinforce the concept that cell-mediated inflammation plays an important role in cerebral vasospasm after SAH and suggest that therapeutic targeting of cellular adhesion molecules can be of benefit in treating cerebral vasospasm.