Calcium antagonists in patients with aneurysmal subarachnoid hemorrhage: a systematic review

An L-type calcium channel blocker nimodipine exerts anti-fibrotic effects by attenuating TGF-β1 induced calcium response in an in vitro model of thyroid eye disease

BACKGROUND

Thyroid eye disease (TED) is a vision-threatening autoimmune disorder. Orbital tissue fibrosis leading to intractable complications remains a troublesome issue in TED management. Exploration of novel therapeutic targets and agents to ameliorate tissue fibrosis is crucial for TED. Recent work suggests that Ca2+ signaling participates in tissue fibrosis. However, whether an alteration of Ca2+ signaling has a role in fibrogenesis during TED remains unclear. In this study, we aimed to investigate the role of Ca2+ signaling in the fibrogenesis process during TED and the potential therapeutic effects of a highly selective inhibitor of the L-type calcium channel (LTCC), nimodipine, through a TGF-β1 induced in vitro TED model.

METHODS

Primary culture of orbital fibroblasts (OFs) were established from orbital adipose connective tissues of patients with TED and healthy control donors. Real-time quantitative polymerase chain reaction (RT-qPCR) and RNA sequencing were used to assess the genes expression associated with LTCC in OFs. Flow cytometry, RT-qPCR, 5-ethynyl-2'-deoxyuridine (EdU) proliferation assay, wound healing assay and Western blot (WB) were used to assess the intracellular Ca2+ response on TGF-β1 stimulation, and to evaluate the potential therapeutic effects of nimodipine in the TGF-β1 induced in vitro TED model. The roles of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and signal transducer and activator of transcription 1 (STAT1) in fibrogenesis during TED were determined by immunohistochemistry, WB, flow cytometry and co-immunoprecipitation assay. Selective inhibitors were used to explore the downstream signaling pathways.

RESULTS

LTCC inhibitor nimodipine blocked the TGF-β1 induced intracellular Ca2+ response and further reduced the expression of alpha-smooth muscle actin (α-SMA), collagen type I alpha 1 (Col1A1) and collagen type I alpha 2 (Col1A2) in OFs. Besides, nimodipine inhibited cell proliferation and migration of OFs. Moreover, our results provided evidence that activation of the CaMKII/STAT1 signaling pathway was involved in fibrogenesis during TED, and nimodipine inhibited the pro-fibrotic functions of OFs by down-regulating the CaMKII/STAT1 signaling pathway.

CONCLUSIONS

TGF-β1 induces an LTCC-mediated Ca2+ response, followed by activation of CaMKII/STAT1 signaling pathway, which promotes the pro-fibrotic functions of OFs and participates in fibrogenesis during TED. Nimodipine exerts potent anti-fibrotic benefits in vitro by suppressing the CaMKII/STAT1 signaling pathway. Our work deepens our understanding of the fibrogenesis process during TED and provides potential therapeutic targets and alternative candidate for TED.

Is Stent Retraction to ReLieve Arterial Cerebral VaSospasm Caused by SAH (Stent-ReLACSS) Using PRELAX the Long-awaited Solution for Treatment of Posthemorrhagic Cerebral Vasospasm? : Treatment of Posthemorrhagic Cerebral Vasospasm with PRESET and PRELAX: Technical Aspects, Efficacy, and Safety Margins in a Case Series

PURPOSE

Recent observational studies have indicated the efficacy of stent retriever devices for the treatment of posthemorrhagic cerebral vasospasm (CVS), both by deployment and on-site withdrawal into the microcatheter (stent angioplasty, SA) and deployment followed by retraction through the target vessel similar to thrombectomy (Stent Retraction to reLieve Arterial Cerebral vaSospasm caused by SAH, Stent-ReLACSS). This article reports the findings with each application of pRESET and pRELAX in the treatment of CVS.

METHODS

We retrospectively enrolled 25 patients with severe CVS following aneurysmal subarachnoid hemorrhage. For the SA group, a stent retriever or a pRELAX was temporarily deployed into a narrow vessel segment and retrieved into the microcatheter after 3 min. For the Stent-ReLACSS group, a pRELAX was temporarily deployed into a narrow vessel and pulled back unfolded into the internal carotid artery. If intra-arterial vasodilators were administered, they were given exclusively after mechanical vasospasmolysis to maximize the effectiveness of the stent treatment.

RESULTS

In this study fifteen patients and 49 vessels were treated with SA. All were technically successful without periprocedural complications; however, 8/15 patients (53.3%) required additional treatment of the CVS. A total of 10 patients and 23 vessel segments were treated with Stent-ReLACSS. All maneuvers were technically successful without periprocedural complications and all vessels showed significant angiographic improvement. No recurrent CVS requiring further endovascular treatment occurred in-hospital, and neither territorial ischemia in the treated vessels nor vascular injury were observed in follow-up angiography.

CONCLUSION

Based on the presented data it appears that Stent-ReLACSS with pRELAX does not pose any additional risks when used to treat CVS and might be superior to SA, especially concerning mid-term and long-term efficacy. The mechanism of action may be an effect on the endothelium rather than mechanical vasodilation. As many patients with CVS are diagnosed too late, prophylactic treatment of high-risk patients (e.g., poor grade, young, female) is potentially viable.

Beyond nimodipine: advanced neuroprotection strategies for aneurysmal subarachnoid hemorrhage vasospasm and delayed cerebral ischemia

The clinical management of aneurysmal subarachnoid hemorrhage (SAH)-associated vasospasm remains a challenge in neurosurgical practice, with its prevention and treatment having a major impact on neurological outcome. While considered a mainstay, nimodipine is burdened by some non-negligible limitations that make it still a suboptimal candidate of pharmacotherapy for SAH. This narrative review aims to provide an update on the pharmacodynamics, pharmacokinetics, overall evidence, and strength of recommendation of nimodipine alternative drugs for aneurysmal SAH-associated vasospasm and delayed cerebral ischemia. A PRISMA literature search was performed in the PubMed/Medline, Web of Science, ClinicalTrials.gov, and PubChem databases using a combination of the MeSH terms "medical therapy," "management," "cerebral vasospasm," "subarachnoid hemorrhage," and "delayed cerebral ischemia." Collected articles were reviewed for typology and relevance prior to final inclusion. A total of 346 articles were initially collected. The identification, screening, eligibility, and inclusion process resulted in the selection of 59 studies. Nicardipine and cilostazol, which have longer half-lives than nimodipine, had robust evidence of efficacy and safety. Eicosapentaenoic acid, dapsone and clazosentan showed a good balance between effectiveness and favorable pharmacokinetics. Combinations between different drug classes have been studied to a very limited extent. Nicardipine, cilostazol, Rho-kinase inhibitors, and clazosentan proved their better pharmacokinetic profiles compared with nimodipine without prejudice with effective and safe neuroprotective role. However, the number of trials conducted is significantly lower than for nimodipine. Aneurysmal SAH-associated vasospasm remains an area of ongoing preclinical and clinical research where the search for new drugs or associations is critical.

Nimodipine Protects Vascular and Cognitive Function in an Animal Model of Cerebral Small Vessel Disease

BACKGROUND

Cerebral small vessel disease is a common cause of vascular cognitive impairment and dementia. There is an urgent need for preventative treatments for vascular cognitive impairment and dementia, and reducing vascular dysfunction may provide a therapeutic route. Here, we investigate whether the chronic administration of nimodipine, a central nervous system-selective dihydropyridine calcium channel blocking agent, protects vascular, metabolic, and cognitive function in an animal model of cerebral small vessel disease, the spontaneously hypertensive stroke-prone rat.

METHODS

Male spontaneously hypertensive stroke-prone rats were randomly allocated to receive either a placebo (n=24) or nimodipine (n=24) diet between 3 and 6 months of age. Animals were examined daily for any neurological deficits, and vascular function was assessed in terms of neurovascular and neurometabolic coupling at 3 and 6 months of age, and cerebrovascular reactivity at 6 months of age. Cognitive function was evaluated using the novel object recognition test at 6 months of age.

RESULTS

Six untreated control animals were terminated prematurely due to strokes, including one due to seizure, but no treated animals experienced strokes and so had a higher survival (P=0.0088). Vascular function was significantly impaired with disease progression, but nimodipine treatment partially preserved neurovascular coupling and neurometabolic coupling, indicated by larger (P<0.001) and more prompt responses (P<0.01), and less habituation upon repeated stimulation (P<0.01). Also, animals treated with nimodipine showed greater cerebrovascular reactivity, indicated by larger dilation of arterioles (P=0.015) and an increase in blood flow velocity (P=0.001). This protection of vascular and metabolic function achieved by nimodipine treatment was associated with better cognitive function (P<0.001) in the treated animals.

CONCLUSIONS

Chronic treatment with nimodipine protects from strokes, and vascular and cognitive deficits in spontaneously hypertensive stroke-prone rat. Nimodipine may provide an effective preventive treatment for stroke and cognitive decline in cerebral small vessel disease.

Nimodipine prophylaxis in aneurysmal subarachnoid hemorrhage, a question of tradition or evidence: A scoping review

BACKGROUND

The prophylactic use of nimodipine following subarachnoid hemorrhage is a practice established four decades ago when clinical management differed from current and the concept of Delayed Cerebral Ischemia (DCI) was not established. The applicability of the original studies is limited by the fact of not reflecting current practice; by utilising a dichotomised outcome measure such as good neurological outcome versus death and vegetative state; by applying variable dosing regimens and including all causes of poor neurological outcome different than DCI. This study aims to review the available evidence to discuss the ongoing role of nimodipine in contemporaneous clinical practice.

METHODS

PRISMA guidelines based review, evaluated the evidence on the prophylactic use of nimodipine. The following search engines: Medline, Embase, Cochrane, Web of Science and PubMed, identified Randomized Control Trials (RCTs) with neurological benefit as outcome measure and the impact of fixed versus weight-based nimodipine dosing regimens.

RESULTS

Eight RCT were selected. Three of those trials with a total of 349 patients, showed a reduction on death and vegetative state (pooled RR: 0.62; 95 % confidence interval-CI: 0.45, 0.86) related to DCI. Amongst all studies, all cause death (pooled RR = 0.73, [95 % CI: 0.56, 0.97]) favoured a fixed-dose regimen (pooled RR: 0.60; [95 % CI: 0.43, 0.85]).

CONCLUSION

Available evidence demonstrates that nimodipine only reduces the risk for DCI-related death or vegetative state and that fixed-dose regimens favour all cause infarct and death independent of DCI. Contemporaneous studies assessing the benefit of nimodipine beyond death or vegetative states and applying individualized dosing are warranted.

Nimodipine accelerates the restoration of functional hyperemia during spreading oligemia

Spreading depolarization (SD) is assumed to be the pathophysiological correlate of migraine aura, leading to spreading depression of activity and a long-lasting vasoconstriction known as spreading oligemia. Furthermore, cerebrovascular reactivity is reversibly impaired after SD. Here, we explored the progressive restoration of impaired neurovascular coupling to somatosensory activation during spreading oligemia. Also, we evaluated whether nimodipine treatment accelerated the recovery of impaired neurovascular coupling after SD. Male, 4-9-month-old C57BL/6 mice (n = 11) were anesthetized with isoflurane (1%-1.5%), and SD was triggered with KCl through a burr hole made at the caudal parietal bone. EEG and cerebral blood flow (CBF) were recorded minimally invasively with a silver ball electrode and transcranial laser-Doppler flowmetry, rostral to SD elicitation. The L-type voltage-gated Ca2+ channel blocker nimodipine was administered i.p. (10 mg/kg). Whisker stimulation-related evoked potentials (EVPs) and functional hyperemia were assessed under isoflurane (0.1%)-medetomidine (0.1 mg/kg i.p.) anesthesia before, and repeatedly after SD, at 15-min intervals for 75 minutes. Nimodipine accelerated the recovery of CBF from spreading oligemia (time to full recovery, 52 ± 13 vs. 70 ± 8 min, nimodipine vs. control) and exhibited a tendency to shorten the duration of the SD-related EGG depression duration. The amplitudes of EVP and functional hyperemia were markedly reduced after SD, and progressively recovered over an hour post-SD. Nimodipine exerted no impact on EVP amplitude but consistently increased the absolute level of functional hyperemia from 20 min post-CSD (93 ± 11% vs. 66 ± 13%, nimodipine vs. control). A linear, positive correlation between EVP and functional hyperemia amplitude was skewed by nimodipine. In conclusion, nimodipine facilitated CBF restoration from spreading oligemia and the recovery of functional hyperemia post-SD, which were linked to a tendency of an accelerated return of spontaneous neural activity after SD. The use of nimodipine in migraine prophylaxis is suggested to be re-visited.

All Three Supersystems-Nervous, Vascular, and Immune-Contribute to the Cortical Infarcts After Subarachnoid Hemorrhage

The recently published DISCHARGE-1 trial supports the observations of earlier autopsy and neuroimaging studies that almost 70% of all focal brain damage after aneurysmal subarachnoid hemorrhage are anemic infarcts of the cortex, often also affecting the white matter immediately below. The infarcts are not limited by the usual vascular territories. About two-fifths of the ischemic damage occurs within ~ 48 h; the remaining three-fifths are delayed (within ~ 3 weeks). Using neuromonitoring technology in combination with longitudinal neuroimaging, the entire sequence of both early and delayed cortical infarct development after subarachnoid hemorrhage has recently been recorded in patients. Characteristically, cortical infarcts are caused by acute severe vasospastic events, so-called spreading ischemia, triggered by spontaneously occurring spreading depolarization. In locations where a spreading depolarization passes through, cerebral blood flow can drastically drop within a few seconds and remain suppressed for minutes or even hours, often followed by high-amplitude, sustained hyperemia. In spreading depolarization, neurons lead the event, and the other cells of the neurovascular unit (endothelium, vascular smooth muscle, pericytes, astrocytes, microglia, oligodendrocytes) follow. However, dysregulation in cells of all three supersystems-nervous, vascular, and immune-is very likely involved in the dysfunction of the neurovascular unit underlying spreading ischemia. It is assumed that subarachnoid blood, which lies directly on the cortex and enters the parenchyma via glymphatic channels, triggers these dysregulations. This review discusses the neuroglial, neurovascular, and neuroimmunological dysregulations in the context of spreading depolarization and spreading ischemia as critical elements in the pathogenesis of cortical infarcts after subarachnoid hemorrhage.

The impact of pre-ictal statin use on vasospasm and outcome in aneurysmal subarachnoid hemorrhage

BACKGROUND

Pleiotropic effects of statins may be beneficial in alleviating cerebral vasospasm (VS) and improving outcome after aneurysmal subarachnoid hemorrhage (aSAH). Initiation of statin treatment at aSAH is not recommended; however, the effect of pre-ictal and continued statin use is not fully investigated.

METHODS

Retrospective study comparing aSAH patients admitted in 2012 to 2021 with pre-ictal statin use versus those not using statins. Patient entry variables, radiological/sonological VS, symptomatic VS, and radiologically documented delayed cerebral ischemia (DCI) were registered. Outcome was scored in terms of mortality, modified Rankin score, Glasgow outcome score extended, and levels of fatigue. Patients were compared on group level and in a case-control design.

RESULTS

We included 961 patients, with 204 (21.2%) statin users. Statin users were older and had more often hypertension. Severe radiological/sonological VS, symptomatic VS, and DCI were less frequent in statin users, and their length of stay was shorter. Mortality, functional outcome, and levels of fatigue were similar in both groups. When analyzing 89 pairs of statin users and non-statin users matched for age, aSAH severity, gender, and hypertension, we confirmed decreased radiological/sonological and symptomatic VS as well as shorter length of stay in statin users. They also had more often a favorable functional outcome and lower levels of fatigue.

CONCLUSIONS

Patients with pre-ictal and continued use of statins have a reduced occurrence of radiological/sonological and symptomatic VS, shorter length of stay, and more often favorable functional outcome, whereas mortality is similar to non-statin users. Even though larger multicenter studies with common, strict protocols for prevention, diagnosis, and treatment of vasospasm are needed to finally establish the value of statins in aSAH, continuation of pre-ictal statin use seems worthwhile.

Novel Insights into Pathophysiology of Delayed Cerebral Ischemia: Effects of Current Rescue Therapy on Microvascular Perfusion Heterogeneity

General microvascular perfusion and its heterogeneity are pathophysiological features of delayed cerebral ischemia (DCI) that are gaining increasing attention. Recently, CT perfusion (CTP) imaging has made it possible to evaluate them radiologically using mean transit time (MTT) and its heterogeneity (measured by cvMTT). This study evaluates the effect of multimodal rescue therapy (intra-arterial nimodipine administration and elevation of blood pressure) on MTT and cvMTT during DCI in aneurysmal subarachnoid haemorrhage (aSAH) patients. A total of seventy-nine aSAH patients who underwent multimodal rescue therapy between May 2012 and December 2019 were retrospectively included in this study. CTP-based perfusion impairment (MTT and cvMTT) on the day of DCI diagnosis was compared with follow-up CTP after initiation of combined multimodal therapy. The mean MTT was significantly reduced in the follow-up CTP compared to the first CTP (3.7 ± 0.7 s vs. 3.3 ± 0.6 s; p < 0.0001). However, no significant reduction of cvMTT was observed (0.16 ± 0.06 vs. 0.15 ± 0.06; p = 0.44). Mean arterial pressure was significantly increased between follow-up and first CTP (98 ± 17 mmHg vs. 104 ± 15 mmHg; p < 0.0001). The combined multimodal rescue therapy was effective in addressing the general microvascular perfusion impairment but did not affect the mechanisms underlying microvascular perfusion heterogeneity. This highlights the need for research into new therapeutic approaches that also target these pathophysiological mechanisms of DCI.

Role of endovascular super selective intra-arterial injection of CA channel blocker agent (nimodipine) in management of cerebral vasospasm following aneurysmal SAH: a single institution experience

Background

Vasospasm is a grave complication of aneurysmal subarachnoid hemorrhage (SAH) with a significant rate of morbidity and mortality. Endovascular intra-arterial injection of Ca channel blocker agent (Nimodipine) may offer a promising solution in refractory vasospasm.

Results

During the period between April 2017 and May 2019, 120 patients who presented with SAH due to a ruptured intracranial aneurysm were admitted to the neurosurgery department at Alexandria University Hospitals. Among them, 30 patients developed refractory vasospasm and were subjected to endovascular super selective intraarterial injection of nimodipine. The angiographic improvement was excellent in three (10%), good in 14 (46%) and poor in the remaining 13 procedures (43%). Clinical improvement was achieved in 15 cases while 15 cases showed no improvement on Modified Rankin Scale. No cases deteriorated following the injection.

Conclusions

Endovascular chemical angioplasty using a ca channel blocker agent (Nimodipine) is a safe and efficient method for the treatment of refractory post aneurysmal SAH vasospasm. The quest is still needed for developing a better efficient agent to overcome the vasospasm dilemma.

Less-invasive subdural electrocorticography for investigation of spreading depolarizations in patients with subarachnoid hemorrhage

Introduction

Wyler-strip electrodes for subdural electrocorticography (ECoG) are the gold standard for continuous bed-side monitoring of pathological cortical network events, such as spreading depolarizations (SD) and electrographic seizures. Recently, SD associated parameters were shown to be (1) a marker of early brain damage after aneurysmal subarachnoid hemorrhage (aSAH), (2) the strongest real-time predictor of delayed cerebral ischemia currently known, and (3) the second strongest predictor of patient outcome at 7 months. The strongest predictor of patient outcome at 7 months was focal brain damage segmented on neuroimaging 2 weeks after the initial hemorrhage, whereas the initial focal brain damage was inferior to the SD variables as a predictor for patient outcome. However, the implantation of Wyler-strip electrodes typically requires either a craniotomy or an enlarged burr hole. Neuromonitoring via an enlarged burr hole has been performed in only about 10% of the total patients monitored.

Methods

In the present pilot study, we investigated the feasibility of ECoG monitoring via a less invasive burrhole approach using a Spencer-type electrode array, which was implanted subdurally rather than in the depth of the parenchyma. Seven aSAH patients requiring extraventricular drainage (EVD) were included. For electrode placement, the burr hole over which the EVD was simultaneously placed, was used in all cases. After electrode implantation, continuous, direct current (DC)/alternating current (AC)-ECoG monitoring was performed at bedside in our Neurointensive Care unit. ECoGs were analyzed following the recommendations of the Co-Operative Studies on Brain Injury Depolarizations (COSBID).

Results

Subdural Spencer-type electrode arrays permitted high-quality ECoG recording. During a cumulative monitoring period of 1,194.5 hours and a median monitoring period of 201.3 (interquartile range: 126.1-209.4) hours per patient, 84 SDs were identified. Numbers of SDs, isoelectric SDs and clustered SDs per recording day, and peak total SD-induced depression duration of a recording day were not significantly different from the previously reported results of the prospective, observational, multicenter, cohort, diagnostic phase III trial, DISCHARGE-1. No adverse events related to electrode implantation were noted.

Discussion

In conclusion, our findings support the safety and feasibility of less-invasive subdural electrode implantation for reliable SD-monitoring.

Evaluation of the synergistic effects of epigallocatechin-3-gallate-loaded PEGylated-PLGA nanoparticles with nimodipine against neuronal injury after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating subtype of stroke with high mortality and morbidity. Although serious side effects might occur, nimodipine, a second-generation 1,4-dihydropyridine calcium channel blocker, is clinically used to improve neurological outcomes after SAH. Recently, (-)-epigallocatechin-3-gallate (EGCG) has been reported to inhibit Ca²⁺ overloading-induced mitochondrial dysfunction, oxidative stress, and neuronal cell death after SAH; however, low bioavailability, instability, and cytotoxicity at a high dose limited the clinical application of EGCG. To overcome these limitations, PEGylated-PLGA EGCG nanoparticles (EGCG-NPs) were constructed to enhance the bioavailability by using the double-emulsion method. Antioxidative activity, cytotoxicity, behavioral, and immunohistochemistry studies were carried out to determine the neuroprotective effectiveness after cotreatment with EGCG-NPs (75 mg/kg/d preconditioning for 7 days before SAH) and nimodipine (10 mg/kg/d after 30 min of SAH) by using in vivo SAH models. The optimized EGCG-NPs with a Box-Behnken design showed a small particle size of 167 nm, a zeta potential value of -22.6 mV, an encapsulation efficiency of 86%, and a sustained-release profile up to 8 days in vitro. Furthermore, EGCG-NPs (75 mg/kg/d) had superior antioxidative activity to free EGCG (100 mg/kg/d). EGCG-NPs combined with nimodipine exhibited significant synergistic effects against neuronal cell death by suppressing oxidative stress, Ca²⁺ overloading, mitochondrial dysfunction, and autophagy after SAH. These results suggest that cotreatment with EGCG-NPs and nimodipine may serve as a promising novel strategy for the treatment of SAH.

Brain Oxygen-Directed Management of Aneurysmal Subarachnoid Hemorrhage. Temporal Patterns of Cerebral Ischemia During Acute Brain Attack, Early Brain Injury, and Territorial Sonographic Vasospasm

BACKGROUND

Neurocritical management of aneurysmal subarachnoid hemorrhage focuses on delayed cerebral ischemia (DCI) after aneurysm repair.

METHODS

This study conceptualizes the pathophysiology of cerebral ischemia and its management using a brain oxygen-directed protocol (intracranial pressure [ICP] control, eubaric hyperoxia, hemodynamic therapy, arterial vasodilation, and neuroprotection) in patients with subarachnoid hemorrhage, undergoing aneurysm clipping (n = 40).

RESULTS

The brain oxygen-directed protocol reduced Lbo₂ (Pbto₂ [partial pressure of brain tissue oxygen] <20 mm Hg) from 67% to 15% during acute brain attack (<24 hours of ictus), by increasing Pbto₂ from 11.31 ± 9.34 to 27.85 ± 6.76 (P < 0.0001) and then to 29.09 ± 17.88 within 72 hours. Day-after-bleed, Fio₂ change, ICP, hemoglobin, and oxygen saturation were predictors for Pbto₂ during early brain injury. Transcranial Doppler ultrasonography velocities (>20 cm/second) increased at day 2. During DCI caused by territorial sonographic vasospasm (TSV), middle cerebral artery mean velocity (V_m) increased from 45.00 ± 15.12 to 80.37 ± 38.33/second by day 4 with concomitant Pbto₂ reduction from 29.09 ± 17.88 to 22.66 ± 8.19. Peak TSV (days 7-12) coincided with decline in Pbto₂. Nicardipine mitigated Lbo₂ during peak TSV, in contrast to nimodipine, with survival benefit (P < 0.01). Intravenous and cisternal nicardipine combination had survival benefit (Cramer Φ = 0.43 and 0.327; G² = 28.32; P < 0.001). This study identifies 4 zones of Lbo₂ during survival benefit (Cramer Φ = 0.43 and 0.3) TSV, uncompensated; global cerebral ischemia, compensated, and normal Pbto₂. Admission Glasgow Coma Scale score (not increased ICP) was predictive of low Pbto₂ (β = 0.812, R² = 0.661, F_1,30 = 58.41; P < 0.0001) during early brain injury. Coma was the only credible predictor for mortality (odds ratio, 7.33/>4.8∗; χ² = 7.556; confidence interval, 1.70-31.54; P < 0.01) followed by basilar aneurysm, poor grade, high ICP and Lbo₂ during TSV. Global cerebral ischemia occurs immediately after the ictus, persisting in 30% of patients despite the high therapeutic intensity level, superimposed by DCI during TSV.

CONCLUSIONS

We propose implications for clinical practice and patient management to minimize cerebral ischemia.

Role of Nimodipine and Milrinone in Delayed Cerebral Ischemia

OBJECTIVE

The role of nimodipine and milrinone in the management of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) was studied using clinical and TCD (transcranial Doppler) parameters.

METHODS

In this prospective observational study, patients with DCI after aneurysmal SAH presenting between November 2020 and June 2021 who were treated by either intra-arterial nimodipine (IAN) or intravenous milrinone (IVM) were included after excluding patients in whom both IAN and IVM had been given or mechanical angioplasty was performed. Twelve-hourly TCD was performed during the course of the therapy. Clinical improvement and the development of new brain infarcts were also assessed. A P value <0.05 was considered statistically significant.

RESULTS

Thirty-four patients fulfilled the inclusion criteria (IVM, 13/34 [38%]; IAN, 21/34 [62%]); patients in the IVM group (vs. IAN group) had poorer median Glasgow Coma Scale score (12 vs. 13), poorer motor response (<M6 response, 5/13 [38%] vs. 5/21 [24%]; P = 0.36) and higher grades (modified Fisher grade ≥3) of SAH (12/13 [92%] vs. 8/21 [86%]; P = 0.56). More patients in the IAN group (vs. IVM group) showed clinical improvement (17/21 [81%] vs. 10/13 [77%]; P = 0.77), development of new infarcts (15/21 [71%] vs. 7/13 [54%]; P = 0.29] and discharged to home (13/21 [62%] vs. 6/13 [46%]; P = 0.36) with less mortality (1/21 [9%] vs. 4/13 [23%]; P = 0.037). On TCD analysis, both IAN and IVM protocols showed similar effects in middle cerebral artery vasospasm; however, IAN proved better over time. In group-effect analysis, the IAN protocol was significantly better in anterior cerebral artery and posterior cerebral artery vasospasm compared with IVM protocol.

CONCLUSIONS

In this single-center small study, patients in the IAN group had significantly less mortality compared with the IVM group in the management of DCI after aneurysmal SAH.

Intracranial stenting as a bail-out option for posthemorrhagic cerebral vasospasm: a single-center experience with long-term follow-up

Background

Cerebral vasospasm (CVS) is a leading cause of morbidity and mortality in patients after aneurysmal subarachnoid hemorrhage (aSAH). Endovascular treatment, including intraarterial infusion of drugs with vasodilation effects, and balloon- and stentriever angioplasty, are helpful but may achieve only short-term effects. There is a clinical need for long-lasting treatment of refractory recurrent vasospasm. We report our experience in stent implantation as a treatment for recurrent severe post-SAH vasospasm.

Methods

A retrospective analysis of our institutional database of 883 patients with SAH, managed between January 2010 and December 2021, was performed. Six patients were identified as having received intracranial stenting in the context of post-SAH cerebral vasospasm. All patients were initially treated with intra-arterial infusion of nimodipine and/or milrinone. Self-expanding intracranial stents were implanted during endovascular aneurysm treatment to enable access despite impaired perfusion (Group 1) or as a bail-out strategy after failed intraarterial drug infusion or mechanical treatment (Group 2). All stented patients received dual antiplatelet therapy (DAPT) for 6 months.

Results

Nine vessels in six patients with severe post-SAH vasospasm were stented. The stents were deployed in 16 vessel segments. All attempted implantations were technically successful. All patients demonstrated radiographic and clinical improvement of the vessel narrowing. No recurrent vasospasm or permanent vessel occlusion of the stented vessels was encountered. A thrombus formation in a Group 1 patient resolved under 4 mg eptifibatide IA infusion. During long-term angiographic follow-up, neither in-stent stenosis nor stent occlusion was found.

Conclusions

Endovascular implantation of self-expanding stents is a potential ultima ratio strategy for patients with severe refractory post-SAH cerebral vasospasm. Stents with reduced thrombogenicity (avoiding DAPT) and bioabsorbable self-expanding stents might further advance this concept.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02862-4.

Vasospasm-Related Death after Aneurysmal Subarachnoid Hemorrhage: A Retrospective Case-Control Study

BACKGROUND

Vasospasm after the rupture of an intracranial aneurysm is a frequent phenomenon and is the main cause of morbidity and mortality in patients who have survived intracranial hemorrhage and aneurysm treatment. We analyzed the diagnosis and management of patients with aneurysmal subarachnoid hemorrhage who eventually died from ischemic brain damage due to vasospasm.

METHODS

Between January 2007 and December 2021 (15 years), a total of 1064 patients were diagnosed with an aneurysmal intracranial hemorrhage in a single comprehensive neurovascular center. Vasospasm was diagnosed in 408 patients (38.4%). A total of 187 patients (17.6%) died within 90 days of the aneurysm rupture. In 64 of these 187 patients (33.7%), vasospasm was considered to be the cause of death. In a retrospective analysis, demographic and clinical data for patients without, with non-fatal, and with fatal vasospasm were compared. The patients with fatal vasospasm were categorized into the following subgroups: "no diagnosis and treatment" (Group a), "delayed diagnosis" (Group b), "cardiovascular complications" (Group c), and "vasospasm-treatment complications" (Group d).

RESULTS

Among the patients with fatal vasospasm, 31 (48.4%) were assigned to group a, 26 (40.6%) to group b, seven (10.9%) to group c, and none (0%) to group d.

CONCLUSION

The early recognition of severe posthemorrhagic vasospasm is a prerequisite for any treatment and requires routine diagnostic imaging in all unconscious patients. Aggressive endovascular vasospasm treatment may fail to prevent death but is infrequently the cause of a fatal outcome.

The incidence of cerebral arterial vasospasm following aneurysmal subarachnoid haemorrhage: a systematic review and meta-analysis

Purpose

To describe a pooled estimated incidence of cerebral arterial vasospasm (aVSP) following aneurysmal subarachnoid haemorrhage (aSAH) and to describe sources of variation in the reported incidence.

Methods

We performed a systematic review and meta-analysis of randomised clinical trials (RCTs) and cohort studies. The primary outcome was the proportion of study participants diagnosed with aVSP. We assessed for heterogeneity based on mode of imaging, indication for imaging, study design and clinical characteristics at a study level.

Results

We identified 120 studies, including 19,171 participants. More than 40 different criteria were used to diagnose aVSP. The pooled estimate of the proportion of patients diagnosed with aVSP was 0.42 (95% CI 0.39 to 0.46, I² = 96.5%). There was no evidence that the incidence aVSP was different, nor that heterogeneity was reduced, when the estimate was assessed by study type, imaging modalities, the proportion of participants with high grade CT scores or poor grade clinical scores. The pooled estimate of the proportion of study participants diagnosed with aVSP was higher in studies with routine imaging (0.47, 95% CI 0.43 to 0.52, I² = 96.5%) compared to those when imaging was performed when indicated (0.30, 95% CI 0.25 to 0.36, I² = 94.0%, p for between-group difference < 0.0005).

Conclusion

The incidence of cerebral arterial vasospasm following aSAH varies widely from 9 to 93% of study participants. Heterogeneity in the reported incidence may be due to variation in the criteria used to diagnose aVSP. A standard set of diagnostic criteria is necessary to resolve the role that aVSP plays in delayed neurological deterioration following aSAH.

PROSPERO registration

CRD42020191895

Supplementary Information

The online version contains supplementary material available at 10.1007/s00234-022-03004-w.

Intracranial Venous Alteration in Patients With Aneurysmal Subarachnoid Hemorrhage: Protocol for the Prospective and Observational SAH Multicenter Study (SMS)

Background

Arterial vasospasm has been ascribed as the responsible etiology of delayed cerebral infarction in patients with aneurysmal subarachnoid hemorrhage (aSAH), but other neurovascular structures may be involved. We present the protocol for a multicenter, prospective, observational study focused on analyzing morphological changes in cerebral veins of patients with aSAH.

Methods and Analysis

In a retrospective arm, we will collect head arterial and venous CT angiograms (CTA) of 50 patients with aSAH and 50 matching healthy controls at days 0–2 and 7–10, comparing morphological venous changes. A multicenter prospective observational study will follow. Patients aged ≥18 years of any gender with aSAH will be enrolled at 9 participating centers based on the predetermined eligibility criteria. A sample size of 52 aSAH patients is expected, and 52 healthy controls matched per age, gender, and comorbidities will be identified. For each patient, sequential CTA will be conducted upon admission (day 0–2), at 7–10 days, and at 14–21 days after aSAH, evaluating volumes and morphology of the cerebral deep veins and main cortical veins. One specialized image collecting center will analyze all anonymized CTA scans, performing volumetric calculation of targeted veins. Morphological venous changes over time will be evaluated using the Dice coefficient and the Jaccard index and scored using the Boeckh–Behrens system. Morphological venous changes will be correlated to clinical outcomes and compared between patients with aSAH and healthy-controls, and among groups based on surgical/endovascular treatments for aSAH.

Ethics and Dissemination

This protocol has been approved by the ethics committee and institutional review board of Ethikkommission, SALK, Salzburg, Austria, and will be approved at all participating sites. The study will comply with the Declaration of Helsinki. Written informed consent will be obtained from all enrolled patients or their legal tutors. We will present our findings at academic conferences and peer-reviewed journals.

Approved Protocol Version and Registration

Version 2, 09 June 2021.

The management of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a rare event affecting relatively young patients therefore leading to a high social impact. The management of SAH follows a biphasic course with early brain injuries in the first 72 hours followed by a phase at risk of secondary deterioration due to delayed cerebral ischemia (DCI) in 20 to 30% patients. Cerebral infarction from DCI is the most preventable cause of mortality and morbidity after SAH. DCI prevention, early detection and treatment is therefore advocated. Formerly limited to the occurrence of vasospasm, DCI is now associated with multiple pathophysiological processes involving for instance the macrocirculation, the microcirculation, neurovascular units, and inflammation. Therefore, the therapeutic targets and management strategies are also evolving and are not only focused on proximal vasospasm. In this review, we describe the current knowledge of DCI pathophysiology. We then discuss the diagnosis strategies that may guide physicians at the bedside with a multimodal approach in the unconscious patient. We will present the prevention strategies that have proven efficient as well as future targets and present the therapeutic approach that is currently being developed when a DCI occurs.

Nicardipine Prolonged Release Implants for Prevention of Delayed Cerebral Ischemia after Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis

OBJECTIVES

A paucity of treatments to prevent delayed cerebral ischemia (DCI) has stymied recovery after aneurysmal subarachnoid hemorrhage (aSAH). Nicardipine has long been recognized as a potent cerebrovascular vasodilator with a history off-label use to prevent vasospasm and DCI. Multiple centers have developed nicardipine prolonged release implants (NPRI) that are directly applied during clip ligation to locally deliver nicardipine throughout the vasospasm window. Here we perform a systematic review and meta-analysis to assess whether NPRI confers protection against DCI and improves functional outcomes after aSAH.

MATERIALS AND METHODS

A systematic search of PubMed, Ovid Embase, and Cochrane databases was performed for studies reporting the use of NPRI after aSAH published after January 1, 1980. We included all studies assessing the association of NPRI with DCI and or functional outcomes. Findings from studies with control arms were analyzed using a random effects model. A separate network meta-analysis was performed, including controlled NPRI studies, single-arm NPRI reports, and the control-arms of modern aSAH randomized clinical trials as additional comparators.

RESULTS

The search identified 214 unique citations. Three studies with 284 patients met criteria for the random effects model. The pooled summary odds ratio for the association of NPRI and DCI was 0.21 (95% CI 0.09-0.49, p = 0.0002) with no difference in functional outcomes (OR 1.80, 95% CI 0.63 - 5.16, p = 0.28). 10 studies of 866 patients met criteria for the network meta-analysis. The pooled summary odds ratio for the association of NPRI and DCI was 0.30 (95% CI 0.13-0.89,p = 0.017) with a trend towards improved functional outcomes (OR 1.68, 0.63 - 4.13 95% CI, p = 0.101).

CONCLUSIONS

In these meta-analyses, NPRI decreases the incidence of DCI with a non-significant trend towards improvement in functional outcomes. Randomized trials on the role of intrathecal calcium channel blockers are warranted to evaluate these observations in a prospective manner.

An overview of pharmacotherapy for cerebral vasospasm and delayed cerebral ischemia after subarachnoid hemorrhage

Introduction: Survival from aneurysmal subarachnoid hemorrhage has increased in the past few decades. However, functional outcome after subarachnoid hemorrhage is still suboptimal. Delayed cerebral ischemia (DCI) is one of the major causes of morbidity.Areas covered: Mechanisms underlying vasospasm and DCI after aneurysmal subarachnoid hemorrhage and pharmacological treatment are summarized in this review.Expert opinion: Oral nimodine, an L-type dihydropyridine calcium channel blocker, is the only FDA-approved drug for the prevention and treatment of neurological deficits after aneurysmal subarachnoid hemorrhage. Fasudil, a potent Rho-kinase inhibitor, has also been shown to improve the clinical outcome and has been approved in some countries for use in patients with aneurysmal subarachnoid hemorrhage. Although other drugs, including nicardipine, cilostazol, statins, clazosentan, magnesium and heparin, have been expected to have beneficial effects on DCI, there has been no convincing evidence supporting the routine use of those drugs in patients with aneurysmal subarachnoid hemorrhage in clinical practice. Further elucidation of the mechanisms underlying DCI and the development of effective therapeutic strategies for DCI, including combination therapy, are necessary to further improve the functional outcome and mortality after subarachnoid hemorrhage.

Predictive value of haptoglobin genotype as a risk of cerebral vasospasm after aneurysmal subarachnoid hemorrhage

OBJECTIVE

This study aims to investigate the genetic predisposition of haptoglobin (Hp) genotype as a predictor for cerebral vasospasm (CV) after acute subarachnoid hemorrhage (aSAH) in the Egyptian population. This permits CV risk factors stratification of patients with aSAH. Hence, it will guide the treatment plan and intensive monitoring for those patients.

PATIENTS AND METHODS

The study was carried out at El Matareya Teaching Hospital, Cairo, Egypt. We studied 50 patients with aSAH who were prospectively recruited and followed up by transcranial Doppler (TCD) examination for 14 days following aneurysmal rupture to early detect hemodynamic changes associated with CV and also the occurrence of delayed cerebral ischemia (DCI) as a secondary outcome. In this study, we attempted to analyze Hp genotyping as a potential predictor of CV and DCI during the acute phase of aneurysmal SAH.

RESULTS

As a part of result analyses, among studied patients, 34 patients (68 %) developed CV and 19 patients (38 %) developed DCI. Only history of hypertension [RR = 1.6 (OR = 4)], diabetes mellitus [RR = 1.5 (OR = 3.4)] and smoking [RR = 1.5 (OR = 3.6)] had a significant independent relationship (P < 0.05) with short term risk to develop CV following aSAH. While, Age, sex, hyperlipidemia, cardiovascular disease and peripheral vascular disease, intracranial aneurysm site and size did not achieve significant association for developing CV. Regarding the poor Fisher scale and poor Hunt and Hess score both showed significant association with CV (P < 0.05). Genotyping of Hp protein among our study cohort revealed that the relative distribution of the three haptoglobin genotypes (Hp1-1, HP2-I & HP2-2) among Egyptian patients of aSAH was 14 %, 40 % and 46 %, respectively; (gene proportion being 0.34 for Hp1 and 0.66 for Hp2). Furthermore; Hp 2 allele was associated with radiographic vasospasm detected by TCD among the studied patients (2-2 & 2-1 Vs 1-1: RR = 5.4, OR = 19.8, P < 0.001). In the regression model; Hp genotype expressing Hp-2 allele is predictive for higher risk of development of CV after aSAH. Moreover, searching for the relationship between CV & Hp genotype and the risk for development of DCI; both variables failed to achieve a significant relationship for DCI (P > 0.05).

CONCLUSION

The Hp genotype may determine the susceptibility to cerebral vasospasm after acute aSAH. This has the potential for use in risk stratification by allowing for the identification of those patients requiring intensive monitoring due to their inherent genetic risk for developing CV allowing for the promising selective application of aggressive treatments to those patients.

Nimodipine after aneurysmal subarachnoid hemorrhage: Fourteen-day course for patients that meet criteria for early hospital discharge

BACKGROUND

Randomized-controlled trials and meta-analyses showed nimodipine use after aneurysmal subarachnoid hemorrhage (aSAH) leads to reduction in incidence of cerebral infarction, persistent neurological deficits, and poor outcomes. Trials administered it for 21 days; however, we assessed whether a shorter duration might be reasonable for a subset of patients.

METHODS

We performed a retrospective single-center study to compare outcomes between patients who received ≤14 days, 15-20 days or ≥21 days of nimodipine. Primary outcome was defined as rate of good functional outcome at final follow-up, assessed using dichotomized modified Rankin Score (mRS). Secondary outcomes included median mRS at follow-up, discharge disposition, and readmission for stroke or vasospasm.

RESULTS

195 patients were included: 101 patients received nimodipine for ≤14 days, 72 patients for 15-20 days, and 22 patients for ≥21 days. There were differences in baseline characteristics of the groups. The shorter duration groups had higher admission GCS score (GCS 15 for ≤14 days, GCS 13 for 15-20 days, GCS 8 for ≥21 days, p = 0.003) and lower Hunt-Hess grade (2 for ≤14 days, 3 for 15-20 days, 4 for ≥21 days, p = 0.001). Of the group of patients that received ≤14 days of nimodipine, 3 patients (3%) were readmitted for concerns for possible stroke or vasospasm, but they did not experience worsening of their functional status related to this.

CONCLUSION

Our data suggests a more limited 14-day course of nimodipine therapy after aSAH may be reasonable and efficacious in patients with higher GCS and lower Hunt-Hess grade on presentation.

Nimodipine and Steroid Combination Therapy for Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVE

To evaluate the treatment outcomes of nimodipine and steroid combination therapy for idiopathic sudden sensorineural hearing loss (ISSNHL).

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Seventy-eight patients who were diagnosed with ISSNHL were divided into two group based on the treatment strategies used: steroid+nimodipine (SN, n = 36) and steroid only (SO, n = 42) groups. Based on the level of hearing loss before treatment, subgroup analysis (<90 dB HL, SN-S versus SO-S groups; ≥90 dB HL, SN-P versus SO-P groups) was performed.

INTERVENTIONS

Nimodipine+dexamethasone versus dexamethasone alone.

MAIN OUTCOME MEASURES

Hearing thresholds and complete/partial recovery rate after treatment.

RESULTS

Hearing thresholds after treatment were not significantly different between the SN and SO groups (46.8 ± 29.4 versus 54.8 ± 27.6 dB HL, p = 0.218). However, the complete recovery rate was significantly higher in the SN group than in the SO group (41.7% versus 16.8%, p = 0.014). In subgroup analysis, the complete recovery rate was significantly higher in the SN-S group than in the SO-S group (60.9% versus 19.2%, p = 0.003), whereas the difference between the SN-P and SO-P groups was not significant (7.7% versus 12.5%, p = 0.672). The cumulative incidence of complete recovery was significantly higher in SN-S group than in the SO-S group (p = 0.005); the mean recovery time was 4.4 weeks (95% confidence interval [CI], 2.8-6.1) in the SN-S group and 8.8 weeks (95% CI, 7.0-10.5) in the SO-S group.

CONCLUSIONS

The results of this study suggest that nimodipine and steroid combination therapy for ISSNHL results in a higher complete recovery rate than steroid alone in patients with moderate to severe hearing loss.

The role of nimodipine and magnesium sulfate in the prevention and treatment of vascular spasm in patients in the acute rupture of cerebral aneurysms

Vascular spasm in patients with hemorrhage from rupture of cerebral aneurysms is the main cause of adverse outcomes of the disease. One way to treat persistent contraction of cerebral arteries is to use nimodipine and magnesium sulfate. This literature review presents studies on the use of nimodipine and magnesium sulfate in the treatment of vascular spasm, and highlights the main links of pathogenesis and drug action mechanisms.

Elevated Cerebrospinal Fluid Protein Is Associated with Unfavorable Functional Outcome in Spontaneous Subarachnoid Hemorrhage

BACKGROUND/OBJECTIVE

Subarachnoid hemorrhage (SAH) is a devastating neurologic event for which markers to assess poor outcome are needed. Elevated cerebrospinal fluid (CSF) protein may result from inflammation and blood-brain barrier (BBB) disruption that occurs during SAH. We sought to determine if CSF protein level is associated with functional outcome after SAH.

METHODS

We prospectively collected single-center demographic and clinical data for consecutive patients admitted with spontaneous SAH. Inclusion required an external ventricular drain and daily CSF protein and cellular counts starting within 48 hours of symptom onset and extending through 7 days after onset. Seven-day average CSF protein was determined from daily measured values after correcting for contemporaneous CSF red blood cell (RBC) count. Three-month functional outcome was assessed by telephone interview with good outcome defined as modified Rankin score 0-3. Variables univariately associated with outcome at P less than .25 and measures of hemorrhage volume were included for binary logistic regression model development.

RESULTS

The study included 130 patients (88% aneurysmal SAH, 69% female, 54.8 ± 14.8 years, Glasgow Coma Scale [GCS] 14 [7-15]). Three-month outcome assessment was complete in 112 (86%) patients with good functional outcome in 74 (66%). CSF protein was lower in good outcome (35.3 [20.4-49.7] versus 80.5 [40.5-115.5] mg/dL; P < .001). CSF protein was not associated with cerebral vasospasm, but delayed radiographic infarction on 3 to 12-month neuroimaging was associated with higher CSF protein (46.3 [32.0-75.0] versus 30.2 [20.4-47.8] mg/dL; P = .023). Good 3-month outcome was independently associated with lower CSF protein (odds ratios [OR] .39 [.23-.70] for 75th versus 25th percentile of protein; P = .001) and higher admission GCS (OR 1.23 [1.10-1.37] for good outcome per GCS point increase; P < .001). Parenchymal hematoma predicted worse outcome (OR 6.31 [1.58-25.25]; P = .009). Results were similar after excluding nonaneurysmal SAH and after including CSF RBC count, CT score, and intraventricular hemorrhage volume in models.

CONCLUSIONS

Elevated average CSF protein is associated with poor outcome after spontaneous SAH. Further research should investigate if elevated CSF protein identifies patients in whom mechanisms such as BBB disruption contribute to poor outcome.

Efficacy and safety of milrinone in the treatment of cerebral vasospasm after subarachnoid hemorrhage: a systematic review

Objective

To systematically review the current evidence on the efficacy of milrinone in the treatment of cerebral vasospasm after subarachnoid hemorrhage.

Methods

The Pubmed^®, Cochrane and Embase databases were screened for articles published from April 2001 to February 2019. Two independent reviewers performed the methodological quality screening and data extraction of the studies.

Results

Twenty-two studies were found to be relevant, and only one of these was a randomized control trial. Studies showed marked heterogeneity and weaknesses in key methodological criteria. Most patients presented with moderate to severe vasospasm. Angiography was the main method of diagnosing vasospasm. Intra-arterial administration of milrinone was performed in three studies, intravenous administration was performed in nine studies, and both routes of administration in six studies; the intrathecal route was used in two studies, the cisternal route in one study and endovascular administration in one study. The side effects of milrinone were described in six studies. Twenty-one studies indicated resolution of vasospasm.

Conclusion

The current evidence indicates that milrinone may have a role in treatment of vasospasm after aneurysmal subarachnoid hemorrhage. However, only one randomized control trial was performed, with a low quality level. Our findings indicate the need for future randomized control trials with patient-centered outcomes to provide definitive recommendations.

Nimodipine Reappraised: An Old Drug With a Future

Nimodipine is a dihydropyridine calcium channel antagonist that blocks the flux of extracellular calcium through L-type, voltage-gated calcium channels. While nimodipine is FDAapproved for the prevention and treatment of neurological deficits in patients with aneurysmal subarachnoid hemorrhage (aSAH), it affects myriad cell types throughout the body, and thus, likely has more complex mechanisms of action than simple inhibition of cerebral vasoconstriction. Newer understanding of the pathophysiology of delayed ischemic injury after a variety of acute neurologic injuries including aSAH, traumatic brain injury (TBI) and ischemic stroke, coupled with advances in the drug delivery method for nimodipine, have reignited interest in refining its potential therapeutic use. In this context, this review seeks to establish a firm understanding of current data on nimodipine's role in the mechanisms of delayed injury in aSAH, TBI, and ischemic stroke, and assess the extensive clinical data evaluating its use in these conditions. In addition, we will review pivotal trials using locally administered, sustained release nimodipine and discuss why such an approach has evaded demonstration of efficacy, while seemingly having the potential to significantly improve clinical care.

Transluminal balloon angioplasty for cerebral vasospasm after spontaneous subarachnoid hemorrhage: A single-center experience

OBJECTIVES

After spontaneous subarachnoid hemorrhage (sSAH), cerebral vasospasm (CVS) is a common complication, potentially resulting in infarction mainly responsible for a poor outcome. Intra-arterial vasodilators lead to transient increase of brain perfusion, but only transluminal balloon angioplasty (TBA) promises longer-lasting effects, though it poses the risk of severe complications. Until now, the precise impact of TBA on the course of CVS is not yet finally clarified. Thus we aimed to identify risk factors of recurrent CVS and vasospasm-related infarction following TBA.

PATIENTS AND METHODS

We analyzed 35 patients with CVS after sSAH who received TBA (41 procedures, 99 vessel segments). Gender, age, WFNS grade and Fisher scale, occurrence of intraventricular and intracerebral hemorrhage, localization of the aneurysm and the initial treatment modality were obtained. We assessed functional outcome after 3 months and in-hospital mortality. TBA was analyzed concerning time point, localization, technique, complications and angiographic response. Furthermore, recurrence of CVS and vasospasm-related infarction after TBA were described and risk factors were identified with logistic regression analyses.

RESULTS

In 7 of 35 patients (20%) and in 16 of 99 vessel segments (16%) previously treated with TBA, we found recurrent CVS. Vasospasm-related infarction occurred in 18 cases (18%) in the arterial territories of the TBA-treated vessel segments. The angiographic effect after TBA was mostly classified as good (87%), good response was negatively associated with recurrent CVS (p = 0.004) and vasospasm-related infarction (p = 0.001). We identified only the male gender as a risk factor for vasospasm-related infarction after TBA (p = 0.040). In connection with TBA, only one complication occurred (intracranial dissection).

CONCLUSION

Our data support TBA as a safe and effective therapy for CVS. Nevertheless, recurrent CVS and vasospasm-related infarction were common after TBA and not predictable by clinical conditions on admission or the localization of CVS. A moderate or poor angiographic response after TBA was identified as a risk factor for both, recurrent CVS and vasospasm-related infarction, while male gender was associated with a higher risk of vasospasm-related infarction. Our results augment the still sparse evidence concerning optimal patient selection for this method and provide new aspects for individual therapy decisions.

Outcome of Oral and Intra-arterial Nimodipine Administration After Aneurysmal Subarachnoid Haemorrhage - A Single-centre Study

BACKGROUND

Oral nimodipine is administered to improve clinical outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). In this study, clinical outcome in patients with and without oral nimodipine administration was assessed.

MATERIALS AND METHODS

A total of 105 patients did not receive oral nimodipine but did receive intra-arterial nimodipine in the occurrence of hemodynamically relevant vasospasm after aSAH, whereas 74 patients received applications of both. Demographic/radiological details and clinical presentation were abstracted from the case records.

RESULTS

Patient baseline characteristics were comparable, a predominance of endovascular coiling was shown in cohort 2 (p=0.0135). Severity of initial aSAH and clinical status at admission (Hunt and Hess) was significantly higher in those receiving oral nimodipine. Incidence of angiographic vasospasm was significantly higher in patients not treated with oral nimodipine (p=0.0305); a significantly better outcome measured by the National Institute of Health Stroke Scale (p=0.0213), was noted in those receiving oral nimodipine.

CONCLUSION

Oral nimodipine administration improved clinical outcome of patients after aSAH and should be administered routinely for such patients.

Clinical and experimental aspects of aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) continues to be associated with significant morbidity and mortality despite advances in care and aneurysm treatment strategies. Cerebral vasospasm continues to be a major source of clinical worsening in patients. We intended to review the clinical and experimental aspects of aSAH and identify strategies that are being evaluated for the treatment of vasospasm. A literature review on aSAH and cerebral vasospasm was performed. Available treatments for aSAH continue to expand as research continues to identify new therapeutic targets. Oral nimodipine is the primary medication used in practice given its neuroprotective properties. Transluminal balloon angioplasty is widely utilized in patients with symptomatic vasospasm and ischemia. Prophylactic "triple-H" therapy, clazosentan, and intraarterial papaverine have fallen out of practice. Trials have not shown strong evidence supporting magnesium or statins. Other calcium channel blockers, milrinone, tirilazad, fasudil, cilostazol, albumin, eicosapentaenoic acid, erythropoietin, corticosteroids, minocycline, deferoxamine, intrathecal thrombolytics, need to be further investigated. Many of the current experimental drugs may have significant roles in the treatment algorithm, and further clinical trials are needed. There is growing evidence supporting that early brain injury in aSAH may lead to significant morbidity and mortality, and this needs to be explored further.

Nimodipine-Dependent Protection of Schwann Cells, Astrocytes and Neuronal Cells from Osmotic, Oxidative and Heat Stress Is Associated with the Activation of AKT and CREB

Clinical and experimental data assumed a neuroprotective effect of the calcium channel blocker nimodipine. However, it has not been proven which neuronal or glial cell types are affected by nimodipine and which mechanisms underlie these neuroprotective effects. Therefore, the aim of this study was to investigate the influence of nimodipine treatment on the in vitro neurotoxicity of different cell types in various stress models and to identify the associated molecular mechanisms. Therefore, cell lines from Schwann cells, neuronal cells and astrocytes were pretreated for 24 h with nimodipine and incubated under stress conditions such as osmotic, oxidative and heat stress. The cytotoxicity was measured via the lactate dehydrogenase (LDH) activity of cell culture supernatant. As a result, the nimodipine treatment led to a statistically significantly reduced cytotoxicity in Schwann cells and neurons during osmotic (p ≤ 0.01), oxidative (p ≤ 0.001) and heat stress (p ≤ 0.05), when compared to the vehicle. The cytotoxicity of astrocytes was nimodipine-dependently reduced during osmotic (p ≤ 0.01), oxidative (p ≤ 0.001) and heat stress (not significant). Moreover, a decreased caspase activity as well as an increased proteinkinase B (AKT) and cyclic adenosine monophosphate response element-binding protein (CREB) phosphorylation could be observed after the nimodipine treatment under different stress conditions. These results demonstrate a cell type-independent neuroprotective effect of the prophylactic nimodipine treatment, which is associated with the prevention of stress-dependent apoptosis through the activation of CREB and AKT signaling pathways and the reduction of caspase 3 activity.

Thirty-day readmissions in aneurysmal subarachnoid hemorrhage: A good metric for hospital quality?

Thirty-day readmission rates has been increasingly used by clinicians, hospital administrators, and policy makers as a metric for the quality of care. However, the 30-day readmission rates may be affected by other factors intrinsic to the patient and may not be a good measure of the quality of care provided by the hospital. In this review, we examined the quality of the 30-day readmissions rate as a quality metric for the quality of care provided to patients with aneurysmal subarachnoid hemorrhage (SAH). It has been shown that in this patient population, 30-day readmission rate primarily captures values, such as the number of comorbidities, disease severity, and discharge dispositions. There is little association between SAH 30-day readmission rates and mortality. However, 30-day readmissions may be reduced by increasing early discharge surveillance, providing readmission reduction programs to patients discharged to medical facilities as well as to home, and identifying patients most at risk for readmission.

Calcium channel blockade with nimodipine reverses MRI evidence of cerebral oedema following acute hypoxia

Acute cerebral hypoxia causes rapid calcium shifts leading to neuronal damage and death. Calcium channel antagonists improve outcomes in some clinical conditions, but mechanisms remain unclear. In 18 healthy participants we: (i) quantified with multiparametric MRI the effect of hypoxia on the thalamus, a region particularly sensitive to hypoxia, and on the whole brain in general; (ii) investigated how calcium channel antagonism with the drug nimodipine affects the brain response to hypoxia. Hypoxia resulted in a significant decrease in apparent diffusion coefficient (ADC), a measure particularly sensitive to cell swelling, in a widespread network of regions across the brain, and the thalamus in particular. In hypoxia, nimodipine significantly increased ADC in the same brain regions, normalizing ADC towards normoxia baseline. There was positive correlation between blood nimodipine levels and ADC change. In the thalamus, there was a significant decrease in the amplitude of low frequency fluctuations (ALFF) in resting state functional MRI and an apparent increase of grey matter volume in hypoxia, with the ALFF partially normalized towards normoxia baseline with nimodipine. This study provides further evidence that the brain response to acute hypoxia is mediated by calcium, and importantly that manipulation of intracellular calcium flux following hypoxia may reduce cerebral cytotoxic oedema.

Severity of cerebral vasospasm associated with development of collaterals following aneurysmal subarachnoid hemorrhage

Introduction

Cerebral collateral circulation has been studied extensively in ischemic stroke where it has been shown to be a predictor of reperfusion, final infarct size, and outcome. Little is known about the significance of the collaterals in the setting of aneurysmal subarachnoid hemorrhage (aSAH). We sought to evaluate the effect of cerebral vasospasm on the development of cerebral collaterals following aneurysmal subarachnoid hemorrhage and the effects of the latter on delayed cerebral ischemia (DCI).

Methods

We retrospectively evaluated 64 aSAH patients with evidence of DCI between day 5 and 7, enrolled in a prospectively maintained observational cohort study. Angiograms were evaluated by four blinded neurointerventionalists. We compared good collateral grades to poor collateral grades, additionally we compared enrolled individuals with any collaterals versus patients who had no collaterals.

Results

Inter-rater reliability for collateral grades was substantial (weighted kappa 0.632). Mild vasospasm was more frequent in patients with poor collateral grades compared with patients with good collateral grades (32% vs 4% P=0.012). There was no difference between the collateral groups with regards to DCI, functional, or cognitive outcome. Patients adjudicated to have any collaterals were more likely to have severe vasospasm (62% vs 33% P=0.023) and less likely to have mild vasospasm (37% vs 9% P=0.007). In a multivariable model, vasospasm severity remained associated with collateral status, while aneurysm location was not.

Conclusions

The severity of vasospasm following aSAH was associated with the development of collaterals. There was no difference between collateral grades with regards to DCI or outcome.

Effect of intrathecal milrinone injection via lumbar catheter on delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Delayed cerebral ischemia (DCI) is an important complication after aneurysmal subarachnoid hemorrhage (aSAH). Although intrathecal milrinone injection via lumbar catheter to prevent DCI has been previously reported to be safe and feasible, its effectiveness remains unknown. The goal of this study was to evaluate whether intrathecal milrinone injection treatment after aSAH significantly reduced the incidence of DCI.

METHODS

The prospectively maintained aSAH database was used to identify patients treated between January 2010 and December 2015. The cohort included 274 patients, with group assignment based on treatment with intrathecal milrinone injection or not. A propensity score model was generated for each patient group, incorporating relevant patient variables.

RESULTS

After propensity score matching, 99 patients treated with intrathecal milrinone injection and 99 without treatment were matched on the basis of similarities in their demographic and clinical characteristics. There were significantly fewer DCI events (4% vs 14%, p = 0.024) in patients treated with intrathecal milrinone injection compared with those treated without it. However, there were no significant differences between the 2 groups with respect to their 90-day functional outcomes (46% vs 36%, p = 0.31). The likelihood of chronic secondary hydrocephalus, meningitis, and congestive heart failure as complications of intrathecal milrinone injection therapy was also similar between the groups.

CONCLUSIONS

In propensity score–matched groups, the intrathecal administration of milrinone via lumbar catheter showed significant reduction of DCI following aSAH, without an associated increase in complications.

Endovascular Rescue Therapies for Refractory Vasospasm After Subarachnoid Hemorrhage: A Prospective Evaluation Study Using Multimodal, Continuous Event Neuromonitoring

BACKGROUND

Critical hypoperfusion and metabolic derangement are frequently encountered with refractory vasospasm. Endovascular rescue therapies (ERT) have proven beneficial in selected cases. However, angioplasty (AP) and intraarterial lysis (IAL) are measures of last resort and prospective, quantitative results regarding the efficacy (cerebral oxygenation, metabolism) are largely lacking.

OBJECTIVE

To evaluate the efficacy of ERTs for medically refractory vasospasm using multimodal, continuous event neuromonitoring.

METHODS

To detect cerebral compromise in a timely fashion, sedated patients with aneurysmal subarachnoid hemorrhage received continuous neuromonitoring (p ti O 2 measurement, intraparenchymal microdialysis). ERT (AP and/or IAL) was considered in cases of clinically relevant vasospasm refractory to conservative treatment measures. Oxygen saturation and cerebral and systemic metabolism before and after events of ERT was recorded.

RESULTS

We prospectively included 13 consecutive patients and recorded a total of 25 ERT events: AP (n = 10), IAL (n = 11), or both (AP + IAL, n = 4). Average cerebral p ti O 2 was 10 ± 11 torr before and 49 ± 22 torr after ERT ( P < .001), with a lactate-pyruvate ratio decreasing from 146.6 ± 119.0 to 27.9 ± 10.7 after ERT ( P < .001). Comparable improvement was observed for each type of intervention (AP, IAL, or both). No significant alterations in systemic metabolism could be detected after ERT.

CONCLUSION

Multimodal event neuromonitoring is able to quantify treatment efficacy in subarachnoid hemorrhage-related vasospasm. In our small cohort of highly selected cases, ERT was associated with improvement in cerebral oxygenation and metabolism with reasonable outcome. Event neuromonitoring may facilitate individual and timely optimization of treatment modality according to the individual clinical course.

Spinal Cerebrospinal Fluid Drainage for prevention of Vasospasm in Aneurysmal Subarachnoid Hemorrhage: A Prospective, Randomized controlled study

Introduction

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major cause of mortality and morbidity. Despite various treatment modalities, the optimal management of vasospasm remains elusive. In this regard; we undertook a prospective, randomized controlled study to evaluate the effectiveness of lumbar cerebrospinal fluid drainage (LCSFD) for prevention of cerebral vasospasm and its sequelae.

Materials and Methods

Patients with aneurysmal SAH who met the inclusion criteria were randomized into two groups - Group I (30 patients) underwent LCSFD whereas Group II (30 patients) did not undergo LCSFD. All patients underwent aneurysmal clipping. Both the groups received standard neurosurgical treatment except for LCSFD. The outcome was measured in terms of (1) clinically evident vasospasm; (2) vasospasm-related cerebral infarction; (3) condition of the patient at the time of discharge; and (4) Glasgow outcome score (GOS) at 1- and 3-month follow-up.

Results

LCSFD conferred a statistically significant benefit reducing the incidence of clinical vasospasm from 63% (in non-LCSFD group) to 30% (in LCSFD group) (P = 0.01) and incidence of vasospasm-related cerebral infarction from 53% (in non-LCSFD group) to 20% (in LCSFD group) (P = 0.007). Incidence of vasospasm was quantitatively lower in LCSFD group across all Hunt and Hess grades; however, it was statistically significant in SAH Grade III (P = 0.008). Mean duration of hospital stay was slightly lower in LCSFD group compared to non-LCSFD group; however, it did not reach statistical significance. A higher incidence of meningitis in LCSFD group was not statistically significant. A higher GOS was observed in LCSFD group at 1- and 3-month follow-up as compared to non-LCSFD group.

Conclusion

Drainage of CSF through a lumbar drain following aneurysmal SAH caused a statistically significant reduction in the incidence of clinical and radiological vasospasm and its sequelae. It also shortens the overall duration of hospital stay and improves the outcome as evidenced by a better GOS score at 1- and 3-month follow-up. The results of this prospective, randomized study establish the efficacy of LCSFD in prevention of vasospasm following aneurysmal SAH.

Endovascular Treatment of Symptomatic Vasospasm after Aneurysmal Subarachnoid Hemorrhage: A Three-year Experience

Objective

The cause of severe clinical vasospasm after aneurysmal subarachnoid hemorrhage remains unknown, despite extensive research over the past 30 years. However, the intra-arterial administration of vasodilating agents and balloon angioplasty have been successfully used in severe refractory cerebral vasospasm.

Materials and Methods

We retrospectively analyzed the data of 233 patients admitted to our institute with aneurysmal subarachnoid hemorrhage (SAH) over the past 3 years.

Results

Of these, 27 (10.6%) developed severe symptomatic vasospasm, requiring endovascular therapy. Vasospasm occurred at an average of 5.3 days after SAH. A total of 46 endovascular procedures were performed in 27 patients. Endovascular therapy was performed once in 18 (66.7%) patients, 2 times in 4 (14.8%) patients, 3 or more times in 5 (18.5%) patients. Intra-arterial vasodilating agents were used in 44 procedures (27 with nimodipine infusion, 17 with nicardipine infusion). Balloon angioplasty was performed in only 2 (7.4%) patients. The Average nimodipine infusion volume was 2.47 mg, and nicardipine was 3.78 mg. Most patients recovered after the initial emergency room visit. Two patients (7.4%) worsened, but there were no deaths.

Conclusion

With advances in endovascular techniques, administration of vasodilating agents and balloon angioplasty reduces the morbidity and mortality of vasospasm after aneurysmal SAH.

Cerebral microcirculatory failure after subarachnoid hemorrhage is reversed by hyaluronidase

Aneurysmal subarachnoid hemorrhage remains one of the more devastating forms of stroke due in large part to delayed cerebral ischemia that appears days to weeks following the initial hemorrhage. Therapies exclusively targeting large caliber arterial vasospasm have fallen short, and thus we asked whether capillary dysfunction contributes to delayed cerebral ischemia after subarachnoid hemorrhage. Using a mouse model of subarachnoid hemorrhage and two-photon microscopy we showed capillary dysfunction unrelated to upstream arterial constriction. Subarachnoid hemorrhage decreased RBC velocity by 30%, decreased capillary pulsatility by 50%, and increased length of non-perfusing capillaries by 15%. This was accompanied by severe brain hypoxia and neuronal loss. Hyaluronidase, an enzyme that alters capillary blood flow by removing the luminal glycocalyx, returned RBC velocity and pulsatility to normal. Hyaluronidase also reversed brain hypoxia and prevented neuron loss typically seen after subarachnoid hemorrhage. Thus, subarachnoid hemorrhage causes specific changes in capillary RBC flow independent of arterial spasm, and hyaluronidase treatment that normalizes capillary blood flow can prevent brain hypoxia and injury after subarachnoid hemorrhage. Prevention or treatment of capillary dysfunction after subarachnoid hemorrhage may reduce the incidence or severity of subarachnoid hemorrhage-induced delayed cerebral ischemia.

Effects of 14 Versus 21 Days of Nimodipine Therapy on Neurological Outcomes in Aneurysmal Subarachnoid Hemorrhage Patients

BACKGROUND

Oral nimodipine is standard therapy for patients suffering an aneurysmal subarachnoid hemorrhage (aSAH). During a national drug shortage, nimodipine therapy was shortened from a 21-day course to a 14-day course at our institution.

OBJECTIVE

The objective of this study was to compare neurological outcomes among patients who had previously received the standard duration of therapy compared with those who received a shortened duration as a result of the national drug shortage.

METHODS

This retrospective cohort study evaluated adult patients receiving nimodipine for aSAH from January 2012 to August 2013. Neurological outcome, graded by Modified Rankin Scale (mRS) at hospital discharge, was compared between patients receiving a shortened course and those receiving the standard duration of nimodipine.

RESULTS

A total of 199 aSAH patients were included in the analysis. There were 164 patients in the standard-duration and 35 patients in the shortened-duration group. Baseline patient severity of illness, assessed by SAPS II (Simplified Acute Physiology Score), and severity of aSAH, assessed by Fisher grade, and Hunt and Hess grade scores, did not differ between the treatment groups. A shortened duration of nimodipine was not associated with a higher risk of a poor neurological outcome defined by mRS (odds ratio = 1.85; 95% CI = 0.54-6.32; P = 0.32). Mortality rates were similar between the groups.

CONCLUSIONS

A 14-day course of nimodipine therapy was not associated with worse neurological outcomes in aSAH patients at one institution. More studies are needed prior to recommending a shortened duration of nimodipine therapy in all aSAH patients.

Delayed cerebral ischaemia prevention and treatment after aneurysmal subarachnoid haemorrhage: a systematic review

: The leading cause of morbidity and mortality after surviving the rupture of an intracranial aneurysm is delayed cerebral ischaemia (DCI). We present an update of recent literature on the current status of prevention and treatment strategies for DCI after aneurysmal subarachnoid haemorrhage. A systematic literature search of three databases (PubMed, ISI Web of Science, and Embase) was performed. Human clinical trials assessing treatment strategies, published in the last 5 yr, were included based on full-text analysis. Study data were extracted using tables depicting study type, sample size, and outcome variables. We identified 49 studies meeting our inclusion criteria. Clazosentan, magnesium, and simvastatin have been tested in large high-quality trials but failed to show a beneficial effect. Cilostazol, eicosapentaenoic acid, erythropoietin, heparin, and methylprednisolone yield promising results in smaller, non-randomized or retrospective studies and warrant further investigation. Topical application of nicardipine via implants after clipping has been shown to reduce clinical and angiographic vasospasm. Methods to improve subarachnoid blood clearance have been established, but their effect on outcome remains unclear. Haemodynamic management of DCI is evolving towards euvolaemic hypertension. Endovascular rescue therapies, such as percutaneous transluminal balloon angioplasty and intra-arterial spasmolysis, are able to resolve angiographic vasospasm, but their effect on outcome needs to be proved. Many novel therapies for preventing and treating DCI after aneurysmal subarachnoid haemorrhage have been assessed, with variable results. Limitations of the study designs often preclude definite statements. Current evidence does not support prophylactic use of clazosentan, magnesium, or simvastatin. Many strategies remain to be tested in larger randomized controlled trials.

CLINICAL TRIAL REGISTRATION

This systematic review was registered in the international prospective register of systematic reviews.

PROSPERO

CRD42015019817.

Vasospasm Risk in Surgical ICU Patients With Grade I Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is associated with high mortality. The initial hemorrhage causes death in approximately 25% of patients, with most subsequent mortality being attributable to delayed cerebral ischemia (DCI). Delayed cerebral ischemia generally occurs on post-bleed days 4 through 20, with the incidence peaking at day 8. Because of the risks of DCI, patients with SAH are usually monitored in an intensive care unit (ICU) for 14 to 21 days. Unfortunately, prolonged ICU admissions are expensive and are associated with well-documented risks to patients. We hypothesized that a subset of patients who are at low risk of DCI should be safe to transfer out of the ICU early. All patients admitted to Montefiore Medical Center from 2008 to 2013 with grade I SAH who had their aneurysms successfully protected, had an uncomplicated postoperative course, and had no clinical or ultrasonographic evidence of DCI after day 8 were retrospectively studied. The primary outcome was clinical or ultrasonographic evidence of the development of DCI after day 8. Secondary outcomes included length of ICU and hospital stay and hospital mortality. Forty patients who met the above-mentioned criteria were identified. Of these, only 1 (2.5%) developed ultrasonographic evidence of DCI after day 8 but required no intervention. The mean length of stay in the ICU was until post-bleed day 13, and the mean hospital length of stay was until post-bleed day 14. The in-hospital mortality was 0 of 40. Thus, we identified a low-risk subset of patients with grade I SAH who may be candidates for early transfer out of the ICU.

Advances in the understanding of delayed cerebral ischaemia after aneurysmal subarachnoid haemorrhage

Delayed cerebral ischaemia has been described as the single most important cause of morbidity and mortality in patients who survive the initial aneurysmal subarachnoid haemorrhage. Our understanding of the pathophysiology of delayed cerebral ischaemia is meagre at best and the calcium channel blocker nimodipine remains the only intervention to consistently improve functional outcome after aneurysmal subarachnoid haemorrhage. There is substantial evidence to support cerebral vessel narrowing as a causative factor in delayed cerebral ischaemia, but contemporary research demonstrating improvements in vessel narrowing has failed to show improved functional outcomes. This has encouraged researchers to investigate other potential causes of delayed cerebral ischaemia, such as early brain injury, microthrombosis, and cortical spreading depolarisation. Adherence to a common definition of delayed cerebral ischaemia is needed in order to allow easier assessment of studies using multiple different terms. Furthermore, improved recognition of delayed cerebral ischaemia would not only allow for faster treatment but also better assessment of interventions. Finally, understanding nimodipine's mechanism of action may allow us to develop similar agents with improved efficacy.

Neuroprotective strategies and neuroprognostication after cardiac arrest

Neurocognitive disturbances are common among survivors of cardiac arrest (CA). Although initial management of CA, including bystander cardiopulmonary resuscitation, optimal chest compression, and early defibrillation, has been implemented continuously over the last years, few therapeutic interventions are available to minimize or attenuate the extent of brain injury occurring after the return of spontaneous circulation. In this review, we discuss several promising drugs that could provide some potential benefits for neurological recovery after CA. Most of these drugs have been investigated exclusively in experimental CA models and only limited clinical data are available. Further research, which also considers combined neuroprotective strategies that target multiple pathways involved in the pathophysiology of postanoxic brain injury, is certainly needed to demonstrate the effectiveness of these interventions in this setting. Moreover, the evaluation of neurological prognosis of comatose patients after CA remains an important challenge that requires the accurate use of several tools. As most patients with CA are currently treated with targeted temperature management (TTM), combined with sedative drug therapy, especially during the hypothermic phase, the reliability of neurological examination in evaluating these patients is delayed to 72-96 h after admission. Thus, additional tests, including electrophysiological examinations, brain imaging and biomarkers, have been largely implemented to evaluate earlier the extent of brain damage in these patients.