High-dose methylprednisolone prevents vasospasm after subarachnoid hemorrhage through inhibition of protein kinase C activation

Early Antiinflammatory Therapy Attenuates Brain Damage After Sah in Rats

BACKGROUND

Early inflammatory processes may play an important role in the development of early brain injury (EBI) after subarachnoid hemorrhage (SAH). Experimental studies suggest that anti-inflammatory and membrane-stabilizing drugs might have beneficial effects, although the underlying mechanisms are not fully understood. The aim of this study was to investigate the effect of early treatment with methylprednisolone and minocycline on cerebral perfusion and EBI after experimental SAH.

METHODS

Male Sprague-Dawley rats were subjected to SAH using the endovascular filament model. 30 minutes after SAH, they were randomly assigned to receive an intravenous injection of methylprednisolone (16mg/kg body weight, n=10), minocycline (45mg/kg body weight, n=10) or saline (n=11). Mean arterial blood pressure (MABP), intracranial pressure (ICP) and local cerebral blood flow (LCBF) over both hemispheres were recorded continuously for three hours following SAH. Neurological assessment was performed after 24 hours. Hippocampal damage was analyzed by immunohistochemical staining (caspase 3).

RESULTS

Treatment with methylprednisolone or minocycline did not result in a significant improvement of MABP, ICP or LCBF. Animals of both treatment groups showed a non-significant trend to better neurological recovery compared to animals of the control group. Mortality was reduced and hippocampal damage significantly attenuated in both methylprednisolone and minocycline treated animals.

CONCLUSION

The results of this study suggest that inflammatory processes may play an important role in the pathophysiology of EBI after SAH. Early treatment with the anti-inflammatory drugs methylprednisolone or minocycline in the acute phase of SAH has the potential to reduce brain damage and exert a neuroprotective effect.

Neutrophil depletion after subarachnoid hemorrhage improves memory via NMDA receptors

Cognitive deficits after aneurysmal subarachnoid hemorrhage (SAH) are common and disabling. Patients who experience delayed deterioration associated with vasospasm are likely to have cognitive deficits, particularly problems with executive function, verbal and spatial memory. Here, we report neurophysiological and pathological mechanisms underlying behavioral deficits in a murine model of SAH. On tests of spatial memory, animals with SAH performed worse than sham animals in the first week and one month after SAH suggesting a prolonged injury. Between three and six days after experimental hemorrhage, mice demonstrated loss of late long-term potentiation (L-LTP) due to dysfunction of the NMDA receptor. Suppression of innate immune cell activation prevents delayed vasospasm after murine SAH. We therefore explored the role of neutrophil-mediated innate inflammation on memory deficits after SAH. Depletion of neutrophils three days after SAH mitigates tissue inflammation, reverses cerebral vasoconstriction in the middle cerebral artery, and rescues L-LTP dysfunction at day 6. Spatial memory deficits in both the short and long-term are improved and associated with a shift of NMDA receptor subunit composition toward a memory sparing phenotype. This work supports further investigating suppression of innate immunity after SAH as a target for preventative therapies in SAH.

Treatment of acute ischemic stroke: beyond thrombolysis and supportive care

The initial therapeutic approach to acute ischemic stroke consists of thrombolytic therapy and early initiation of supportive care, usually commenced prior to the determination of the underlying stroke etiology. Varying stroke mechanisms may call for specific, etiology-based treatment. The majority of strokes result from cardioembolism, large-vessel atherothromboembolism, and small-vessel occlusive disease. There are scant data to support the use of acute anticoagulation therapy over anti-platelet therapy in cardioembolic stroke and large-vessel atherosclerosis, although it may be reasonable in a certain subset of patients. However, augmentation of blood flow with early surgery, stenting, or induced hypertension, may play a role in patients with large artery stenosis. The less commonly identified stroke mechanisms may warrant special consideration in treatment. Controversy remains regarding the optimal anti-thrombotic treatment of arterial dissection. Reversible cerebral vasoconstriction syndrome may benefit from therapy with calcium channel blockers, high-dose steroids, or magnesium, although spontaneous recovery may occur. Inflammatory vasculopathies, such as isolated angiitis of the central nervous system and temporal arteritis, require prompt diagnosis as the mainstay of therapy is immunosuppression. Cerebral venous thrombosis is a rare cause of stroke, but one that needs early identification and treatment with anticoagulation. Rapid determination of stroke mechanism is essential for making these critical early treatment decisions.

Randomized, double-blind, placebo-controlled, pilot trial of high-dose methylprednisolone in aneurysmal subarachnoid hemorrhage

OBJECT

The object of this study was to determine the efficacy of methylprednisolone in reducing symptomatic vasospasm and poor outcomes after subarachnoid hemorrhage (SAH).

METHODS

Ninety-five patients with proven SAH were recruited into a double-blind, placebo-controlled, randomized trial. Starting within 6 hours after angiographic diagnosis of aneurysm rupture, placebo or methylprednisolone, 16 mg/kg, was administered intravenously every day for 3 days to 46 and 49 patients, respectively. Deterioration, defined as development of a focal sign or decrease of more than 1 point on the Glasgow Coma Scale for more than 6 hours, was investigated by using clinical criteria and transcranial Doppler ultrasonography, cerebral angiography, or CT when appropriate. The end points were incidence of symptomatic vasospasm (delayed ischemic neurological deficits associated with angiographic arterial narrowing or accelerated flow on Doppler ultrasonography, or both) and outcome 1 year after entry into the study according to a simplified Rankin scale (Functional Outcome Scale [FOS]) in living patients and the Glasgow Outcome Scale in all patients included.

RESULTS

All episodes of deterioration and all living patients with a 1-year outcome were assessed by a review committee. In patients treated with methylprednisolone, the incidence of symptomatic vasospasm was 26.5% compared with 26.0% in those given placebo. Poor outcomes according to FOS were significantly reduced in the Methylprednisolone Group at 1 year of follow-up; the risk difference was 19.3% (95% CI 0.5-37.9%). The outcome was poor in 15% (6/40) of patients in the Methylprednisolone Group versus 34% (13/38) in the Placebo Group.

CONCLUSIONS

A safe and simple treatment with methylprednisolone did not reduce the incidence of symptomatic vasospasm but improved ability and functional outcome at 1 year after SAH.

Role of ERK1/2 and vascular cell proliferation in cerebral vasospasm after experimental subarachnoid hemorrhage

BACKGROUND

Although there are still some unresolved aspects, current research has revealed that vascular cell proliferation probably plays an important part in the pathological formation process of cerebral vasospasm. Using a "two-hemorrhage" model of subarachnoid hemorrhage (SAH), this study investigated the function of ERK1/2 and vascular wall cell proliferation in pathological development of cerebral vasospasm.

METHODS

Fifty rabbits were randomly divided into five groups: (1) SAH day 1, (2) SAH day 3, (3) SAH day 7, (4) SAH + DMSO (dimethyl sufoxide) solution, (5) SAH + PD98059 (a mitogen-activated protein kinase inhibitor) dissolved in DMSO solution. In the SAH + PD98059/DMSO group and SAH + DMSO control group, PD98059 in DMSO (2 mmol/l) or an equal quantity of DMSO, respectively, was injected into the cisterna magna, once a day from SAH day 1 to day 3. Western protein blotting was used to detect the expression of proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in each group's basilar arteries. Light microscopy and electron microscopy were used for dynamic histological detection at each observation point of the SAH vascular wall under the effects of SAH and the mitogen-activated protein kinase inhibitor. Another 18 rabbits were randomly divided into three groups: SAH, SAH + DMSO and SAH + PD98059/DMSO; cerebral angiograpathy was conducted on SAH days 1 and 7, and the progression of angiographic vasospasm evaluated.

RESULTS

Compared with the control group, the extent of vasospasm after SAH increased with time. PD98059 significantly reduced angiographic and morphological vasospasm. In cerebral vasospasm, the expression of T-ERK1/2 showed no significant change. However, expression of p-ERK1/2 and PCNA began to increase significantly on day 3, and achieved a peak on day 7. PD98059 significantly inhibited the expression of p-ERK1/2 and PCNA (p < 0.05).

CONCLUSIONS

Cell proliferation on the vascular wall plays an important part in the pathological formation process of cerebral vasospasm. ERK1/2 phosphorylation, as an important signaling pathway, taking part in the process of vascular-wall pathological proliferation of cerebral vasospasm.

Reversible Cerebral Vasoconstriction Syndrome with Posterior Leucoencephalopathy after Oral Contraceptive Pills

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden-onset recurrent ‘thunderclap’ headaches with reversible multifocal narrowing of the cerebral arteries, often associated with focal neurological deficits from ischaemic or haemorrhagic stroke. It has been associated with exposure to vasoconstrictive drugs, pregnancy, migraine, and a variety of other conditions. Whereas the pathophysiology of RCVS remains unclear, changes in the levels of female hormones are considered important because RCVS predominantly affects women and is frequently associated with pregnancy. We report a patient with angiographically confirmed RCVS whose MRI showed reversible brain oedema, suggesting an overlap between RCVS and the reversible posterior leucoencephalopathy syndrome. The only identified risk factor was oral contraceptive pills started 1 month prior to onset, supporting a role for female reproductive hormones in precipitating this overlap syndrome.

Effects of common medications on cerebral vasospasm after subarachnoid haemorrhage

Cerebral vasospasm is a common and serious complication of aneurysmal subarachnoid haemorrhage (SAH). At present, no consistently effective preventative and therapeutic measures are available, perhaps because of incomplete understanding of the pathogenesis of vasospasm. Experimental studies provide evidence that the incidence and severity of vasospasm after SAH can be modulated by drugs that affect neurotransmitter levels, intracellular signalling mechanisms, vascular smooth muscle function, inflammation and cellular proliferation, and the concentration of 'spasmogenic' factors. Preliminary clinical studies indicate that some illicit drugs and common prescription medications can have similar effects in humans. Recognition of these pharmacological effects is important because medications that can worsen or alleviate vasospasm are frequently administered to SAH patients to treat coincident medical problems.

Controversies in the management of aneurysmal subarachnoid hemorrhage*

BACKGROUND

The care of patients with aneurysmal subarachnoid hemorrhage has evolved significantly with the advent of new diagnostic and therapeutic modalities. Although it is believed that these advances have contributed to improved outcomes, considerable uncertainty persists regarding key areas of management.

OBJECTIVE

To review selected controversies in the management of aneurysmal subarachnoid hemorrhage, with a special emphasis on endovascular vs. surgical techniques for securing aneurysms, the diagnosis and therapy of cerebral vasospasm, neuroprotection, antithrombotic and anticonvulsant agents, cerebral salt wasting, and myocardial dysfunction, and to suggest venues for further clinical investigation.

DATA SOURCE

Search of MEDLINE and Cochrane databases and manual review of article bibliographies.

DATA SYNTHESIS AND CONCLUSIONS

Many aspects of care in patients with aneurysmal subarachnoid hemorrhage remain highly controversial and warrant further resolution with hypothesis-driven clinical or translational research. It is anticipated that the rigorous evaluation and implementation of such data will provide a basis for improvements in short- and long-term outcomes.

Signaling mechanisms in cerebral vasospasm

The elusive nature of events that sustain cerebral vasospasm after subarachnoid hemorrhage resulting from a ruptured aneurysm presents major challenges in designing effective therapies for this frequently devastating condition. Protracted cerebral artery constriction entails several dynamic components in intracellular signaling events initiated by endothelial factors, products of hemolysate, and numerous kinases, as well as increased intracellular Ca(2+). The rationale for potential treatment modalities and their efficacy are discussed in this brief review.