Cerebral Vasospasm Following Subarachnoid Hemorrhage

Risk factors for preoperative seizures in pediatric patients with intracranial aneurysms

OBJECTIVE

Seizures are common complications following intracranial aneurysms and present a greater risk to pediatric patients than adults. Though the risk factors of seizures in adults with intracranial aneurysms have been well documented, the risk factors in pediatric patients remain unknown. The aim of this study was to evaluate the risk factors for preoperative seizures and the effect of the treatment approach on postoperative seizures in pediatric patients with intracranial aneurysms.

PATIENTS AND METHODS

The data of 64 pediatric patients (mean age 11.4 ± 5.7 years; 68.8 % of males) with intracranial aneurysms were retrospectively analyzed from January 2012 to April 2017. Comparisons were made between patients with preoperative seizures (case group) and those without (control group).

RESULTS

Twenty-four patients (37.5 %) had preoperative seizures, and 15 patients (23.4 %) had postoperative seizures. Multiple logistic regression analysis revealed that younger age (0-5 years), head trauma history, ruptured aneurysms, lobe hematomas, modified Fisher grade 3-4, giant aneurysms, pseudoaneurysms and distal arterial aneurysms were independently associated with the increased risk of preoperative seizures. Patients in the surgical and endovascular groups did not differ significantly in the rates of preoperative seizures or early postoperative seizures (within 1 month) (P > 0.05). However, a significantly lower incidence of late postoperative seizures (1-3 months and 3-6 months) was observed in the surgical group compared with the endovascular group (P < 0.05).

CONCLUSION

Pediatric patients with intracranial aneurysms are at high risk for seizures. Risk factors for preoperative seizures included younger age (0-5 years), head trauma history, lobe hematomas, modified Fisher grade 3-4, giant aneurysms, pseudoaneurysms and distal arterial aneurysms. Compared with the endovascular treatment, surgical intervention provided more benefits with regard to reducing the risk of late postoperative seizures.

Radiologic Characteristics and High Risk of Seizures in Infants with Ruptured Intracranial Aneurysms: Case Report and Review of the Literature

OBJECTIVE

To evaluate the parameters related to the high risk of preoperative seizures in infants (1 year or younger) with ruptured intracranial aneurysms.

METHODS

Infants with ruptured intracranial aneurysms treated at our institution from January 2012 to January 2018 were retrospectively analyzed. Seventeen similar cases of infant patients with seizures reported in published studies were reviewed.

RESULTS

The mean age of the 7 infant patients treated at our institution was 4.1 ± 3.3 months (range, 28 days to 11 months), with 2 male and 5 female subjects. One patient (14.3%) had an internal carotid artery aneurysm with subarachnoid hemorrhage, and the remaining 6 patients (85.7%) had middle cerebral artery (MCA) aneurysms in the distal arterial region with lobe hemorrhage. Five of the 7 infants (71.4%) had seizures, 4 of whom (4/5, 80.0%) had MCA distal arterial aneurysms with lobe hemorrhage. Management was successful for all patients with aneurysm clipping or resection surgery, and one patient experienced postoperative seizures. Of the 17 reviewed cases of infant patients with seizures, 10 patients (58.8%) exhibited the typical distal arterial aneurysm with lobe hemorrhaging, and 6 (60%) of them had aneurysms in MCA.

CONCLUSIONS

Infant patients with ruptured intracranial aneurysms have a high risk of preoperative seizures. The typical radiologic finding of distal arterial aneurysm with lobe hemorrhage was frequently observed in the MCA, and it might be related to the high risk of preoperative seizures in this population. Microsurgical techniques effectively control postoperative seizures in infants with ruptured intracranial aneurysms.

Transcranial Doppler ultrasonography: From methodology to major clinical applications

Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler (TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency (≤ 2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays the most widespread indication for TCD in outpatient setting is the research of right to left shunting, responsable of so called “paradoxical embolism”, most often due to patency of foramen ovale which is responsable of the majority of cryptogenic strokes occuring in patients younger than 55 years old. TCD also allows to classify the grade of severity of such shunts using the so called “microembolic signal grading score”. In addition TCD has found many useful applications in neurocritical care practice. It is useful on both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoidal haemorrhage (caused by aneurysm rupture or traumatic injury), traumatic brain injury, brain stem death. It is used also to evaluate cerebral hemodynamic changes after stroke. It also allows to investigate cerebral pressure autoregulation and for the clinical evaluation of cerebral autoregulatory reserve.

Transcranial Doppler Ultrasound: Physical Principles and Principal Applications in Neurocritical Care Unit

Transcranial Doppler (TCD) ultrasonography is a noninvasive ultrasound study, which has been extensively applied on both outpatient and inpatient settings. It involves the use of a low-frequency (≤2 MHz) transducer, placed on the scalp, to insonate the basal cerebral arteries through relatively thin bone windows and to measure the cerebral blood flow velocity and its alteration in many different conditions. In neurointensive care setting, TCD is useful for both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoid hemorrhage, traumatic brain injury, acute ischemic stroke, and brain stem death. It also allows to investigate the cerebrovascular autoregulation in setting of carotid disease and syncope. In this review, we will describe physical principles underlying TCD, flow indices most frequently used in clinical practice and critical care applications in Neurocritical Unit care.

Extent of collateralization predicting symptomatic cerebral vasospasm among pediatric patients: correlations among angiography, transcranial Doppler ultrasonography, and clinical findings

OBJECT

Although the development and prevalence of cerebral vasospasm (CV) has been extensively investigated in adults, little data exist on the development of CV in children. The authors hypothesized that even though children have highly vasoreactive arteries, because of a robust cerebral collateral blood flow, they rarely develop symptomatic CV.

METHODS

The authors retrospectively reviewed their university hospital's neurointerventional database for children (that is, patients ≤ 18 years) who were examined or treated for aneurysmal or traumatic subarachnoid hemorrhage (SAH) during the period 1990-2013. Images from digital subtraction angiography (DSA) were analyzed for the extent of CV and collateralization of the cerebral circulation. Results from transcranial Doppler (TCD) ultrasonography were correlated with those from DSA. Cerebral vasospasm on TCD ultrasonography was defined according to criteria developed for adults. Clinical outcomes of CV were assessed with the pediatric modified Rankin Scale (mRS).

RESULTS

Among 37 children (21 boys and 16 girls ranging in age from 8 months to 18 years) showing symptoms of an aneurysmal SAH (comprising 32 aneurysms and 5 traumatic pseudoaneurysms), 17 (46%) had CV confirmed by DSA; CV was mild in 21% of these children, moderate in 50%, and severe in 29%. Only 3 children exhibited symptomatic CV, all of whom had poor collateralization of cerebral vessels. Among the 14 asymptomatic children, 10 (71%) showed some degree of vessel collateralization. Among 16 children for whom TCD data were available that could be correlated with the DSA findings, 13 (81%) had CV according to TCD criteria. The sensitivity and specificity of TCD ultrasonography for diagnosing CV were 95% and 59%, respectively. The time to CV onset detected by TCD ultrasonography was 5 ± 3 days (range 2-10 days). Twenty-five (68%) of the children had good long-term outcomes (that is, had mRS scores of 0-2).

CONCLUSIONS

Children have a relatively high incidence of angiographically detectable, moderate-to-severe CV. Children rarely develop symptomatic CV and have good long-term outcomes, perhaps due to robust cerebral collateral blood flow. Criteria developed for detecting CV with TCD ultrasonography in adults overestimate the prevalence of CV in children. Larger studies are needed to define TCD ultrasonography-based CV criteria for children.

Transcranial Doppler ultrasound: a review of the physical principles and major applications in critical care

Transcranial Doppler (TCD) is a noninvasive ultrasound (US) study used to measure cerebral blood flow velocity (CBF-V) in the major intracranial arteries. It involves use of low-frequency (≤2 MHz) US waves to insonate the basal cerebral arteries through relatively thin bone windows. TCD allows dynamic monitoring of CBF-V and vessel pulsatility, with a high temporal resolution. It is relatively inexpensive, repeatable, and portable. However, the performance of TCD is highly operator dependent and can be difficult, with approximately 10-20% of patients having inadequate transtemporal acoustic windows. Current applications of TCD include vasospasm in sickle cell disease, subarachnoid haemorrhage (SAH), and intra- and extracranial arterial stenosis and occlusion. TCD is also used in brain stem death, head injury, raised intracranial pressure (ICP), intraoperative monitoring, cerebral microembolism, and autoregulatory testing.

Advances in transcranial Doppler clinical applications

IMPORTANCE OF THE FIELD

Diagnostic neurosonology techniques including transcranial Doppler (TCD), transcranial color Doppler imaging (TCDI) and power motion-mode (PMD) TCD provide information about various aspects of cerebrovascular status such as microemboli detection, dynamic autoregulation and long-duration real-time monitoring of flow characteristics. Although most of the information provided cannot be obtained by any other imaging methodology, and is critical in clinical decision-making in the care of various neurovascular diseases, these modalities are widely underutilized. Increasing the familiarity to neurosonological techniques is of crucial importance.

AREAS COVERED IN THIS REVIEW

After briefly reviewing TCD, TCDI and PMD techniques, classical features are summarized and recent developments in the clinical neurosonology applications with specific interest in the neurovascular disorders.

WHAT THE READER WILL GAIN

Practical perspectives of ultrasound evaluation of intracranial arterial status in various neurovascular diseases including sickle cell vasculopathy and vasospasm are reviewed in detail. Pearls on the neurosonological monitoring of acute ischemic stroke and increased intracranial pressure increase is provided. Standards of cerebral microembolism detection, right to left shunts diagnosis and cerebral autoregulation assessment are discussed methodologically. Future perspectives of therapeutic neurosonology including sonothrombolysis, microbubble-ultrasound-mediated gene and drug delivery into the brain, and alteration of the brain-blood barrier permeability are summarized.

TAKE HOME MESSAGE

Suitable with future medicine, neurosonology brings imaging to the bedside, which enables the treating physician to monitor a given intervention in real time. A non-invasive neurosonology-guided treatment of various diseases could be possible in the near future. The first and foremost step in gaining mastery in this very fruitful field is beginning to use it.

Transcranial Doppler ultrasound in neurovascular diseases: diagnostic and therapeutic aspects

Albeit no direct anatomical information can be obtained, neurosonological methods provide real-time determination of velocity, and spectral waveform of blood flow in basal intracranial arteries adds significant benefit to the care of the patients with neurovascular diseases. Several features, such as relative simplicity in terms of interpretation and performance, significantly low cost, totally non-invasiveness, portability, and excellent temporal resolution, make neurosonology increasingly popular tool for evaluation, planning, and monitoring of treatment, and for determining prognosis in various neurovascular diseases. Usefulness of transcranial Doppler in diagnosing/monitoring subarachnoid hemorrhage related vasospasm and sickle cell vasculopathy is already well known. Utility in diagnosis of intracranial arterial stenosis, acute occlusion and recanalization, intracranial hemodynamic effect of the cervical arterial pathologies, intracranial pressure increase, and cerebral circulatory arrest are also well established. Neurosonological determination of vasomotor reactivity, cerebral autoregulation, neurovascular coupling, and micro-embolic signals detection are useful in the assessment of stroke risk, diagnosis of right-to-left shunting, and monitoring during surgery and interventional procedures. Transcranial Doppler is also an evolving ultrasound method with a therapeutic potential such as augmentation of clot lysis and cerebral delivery of thrombolytic or neuroprotective agent loaded nanobubbles in neurovascular diseases. The aim of this study is to give an overview of current usage of the different ultrasound modalities in different neurovascular diseases.

Role of transcranial Doppler in optimizing treatment of cerebral vasospasm in subarachnoid hemorrhage

This study was undertaken to evaluate the role of transcranial Doppler ultrasonography in arterial blood pressure management during hypervolemia/hypertension/ hemodilution therapy in patients with vasospasm from subarachnoid hemorrhage and correlate this data with neurologic outcome. The study included 18 adult patients, Hunt and Hess grades III-IV. Complete neurologic assessment was performed. Transcranial Doppler indices were calculated by standard formulas. On the basis of our results, resistance area product can be used to estimate the optimal arterial blood pressure in hypervolemia/hypertension/hemodilution therapy. An increase in the cerebral blood flow index was associated with better performance on neurologic examination. Estimated cerebral perfusion pressure from transcranial Doppler data analysis showed poor correlation with cerebral perfusion pressure derived from direct measurement of intracranial pressure in patients with cerebral vasospasm (rho = 0.15; 95% CI, 0.11-0.39; P = .2590).

Novel treatments for cerebral vasospasm following aneurysmal subarachnoid hemorrhage

Cerebral vasospasm is a major cause of cerebral ischemia and poor outcomes in the setting of aneurysmal subarachnoid hemorrhage (SAH). Despite advances in diagnosis and treatment of SAH, the pathophysiology of vasospasm is still poorly understood and outcomes remain disappointing. Recent advances in understanding the role of hemoglobin in initiating an inflammatory cascade in the subarachnoid space open new avenues for therapy. Preliminary experimental and clinical evidence indicate that targets in the inflammatory and oxidative cascades hold promise in reducing the incidence and impact of cerebral vasospasm.

CT and CT-Perfusion Findings of Reversible Leukoencephalopathy During Triple-H Therapy for Symptomatic Subarachnoid Hemorrhage-Related Vasospasm

BACKGROUND

Reversible leukoencephalopathy syndrome (RLS) is an acute neurological syndrome associated with altered mental status and visual disturbances described in patients with sudden elevations in systemic blood pressure and other medical conditions. In this process, neuroimaging studies usually demonstrate diffuse edema involving the subcortical structures of the posterior regions of the brain. Triple H (HHH) therapy is an established treatment for symptomatic vasospasm following subarachnoid hemorrhage (SAH). RLS has not been reported in the scientific literature as a complication of HHH therapy with perfusion computed tomography (CTP) imaging documentation.

CASE

A 73-year-old woman developed iatrogenic RLS during HHH therapy for SAH-related vasospasm. The computed tomography (CT) revealed bilateral parieto-occipital hypodensities. The CTP study showed increased cerebral blood volume and blood flow as well as decreased mean transit time in both parietal-occipital regions, which is compatible with vasogenic edema.

CONCLUSION

The induction of hypertension as part of HHH therapy for SAH-related cerebral vasospasm may result in RLS. Therefore, it should be considered as a potentially reversible cause in the differential diagnosis of neurological deterioration in SAH patients while on HHH therapy. CTP study can offer an alternative for the assessment of this cerebrovascular 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.

Effect of Clipping, Craniotomy, or Intravascular Coiling on Cerebral Vasospasm and Patient Outcome after Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE:

Although several recent studies have suggested that the incidence of vasospasm after aneurysmal subarachnoid hemorrhage is lower in patients undergoing aneurysmal coiling as compared with clipping, other studies have had conflicting results. We reviewed our experience over 8 years and assessed whether clipping, craniotomy, or coiling affects patient outcomes or the risk for vasospasm.

METHODS:

We included 515 patients with aneurysmal subarachnoid hemorrhage, identified prospectively from November 2000 to February 2003 (243 patients) and retrospectively from November 1995 to October 2000 (272 patients), by using International Classification of Diseases, 9th Revision, codes for subarachnoid hemorrhage. We classified patients as follows: clipping (413 patients), coiling (79 patients), and craniotomy (436 patients, including all 413 patients who underwent clipping plus 23 who underwent coiling as well as craniotomy for various reasons). We studied four outcome measures: total vasospasm, symptomatic vasospasm, poor outcome (modified Rankin score 3–6), and in-hospital mortality. To assess the risk of total vasospasm and symptomatic vasospasm, we performed multivariate regression analyses adjusting for age, Fisher grade, Hunt and Hess grade, aneurysm location (anterior versus posterior circulation), and aneurysm treatment modality. To assess the risk for poor outcome and in-hospital mortality, we adjusted for all the above variables as well as for total and symptomatic vasospasm.

RESULTS:

In the clipping group there was 63% total vasospasm and 28% symptomatic vasospasm; in the coiling group there was 54% total vasospasm and 33% symptomatic vasospasm; and in the craniotomy group there was 64% total vasospasm and 28% symptomatic vasospasm. In the multivariate analysis, age &lt;50 years (P = 0.0099) and Fisher Grade 3 (P &lt; 0.00001) predicted total vasospasm, and Fisher Grade 3 (P &lt; 0.000001) and Hunt and Hess Grade IV or V (P = 0.018) predicted symptomatic vasospasm. Predictors of poor outcome were age ≥50 years (P &lt; 0.0001), Fisher Grade 3 (P = 0.0072), Hunt and Hess Grade IV or V (P &lt; 0.00001), symptomatic vasospasm (P &lt; 0.0001), and coiling (P = 0.0314 versus clipping and P = 0.045 versus craniotomy). Predictors of in-hospital mortality were age ≥ 50 years (P = 0.0030), Hunt and Hess Grade IV or V (P = 0.0001), symptomatic vasospasm (P &lt; 0.00001), and coiling (P = 0.008 versus clipping and P = 0.0013 versus craniotomy). There was no significant difference in total vasospasm or symptomatic vasospasm when patients who underwent clipping or craniotomy were compared with patients who underwent coiling. In patients with Hunt and Hess Grade I to III (“good grade”), clipping and craniotomy were associated with better outcome and less in-hospital mortality, but there was no difference in total vasospasm or symptomatic vasospasm versus coiling. In patients with Hunt and Hess Grade IV or V (“poor grade”), there was no difference in any outcome measure among the treatment groups.

CONCLUSION:

In a single-center, retrospective, nonrandomized study, performance of clipping and/or craniotomy had significantly better outcome and lower mortality at discharge than coiling in good-grade patients but had no effect on total vasospasm or symptomatic vasospasm in good- or poor-grade patients.