Clinical presentation of cerebral aneurysms

Preventive clipping versus coiling in unruptured intracranial aneurysms: A comprehensive meta-analysis and systematic review to explore safety and efficacy

BACKGROUND

Surgical clipping and endovascular coiling are both effective in preventing aneurysmal subarachnoid hemorrhage, but the choice between these interventions remains controversial, leading to treatment disparities across medical centers.

METHODS

A systematic review and meta-analysis were conducted, including relevant two-arm clinical trials up to September 2023, sourced from Scopus, PubMed, Web of Science, and the Cochrane Library. Our primary outcomes were complete occlusion rates during mid-term and long-term follow-ups. Standard mean differences and risk ratios were used to analyze variations in outcomes. Python meta-analysis with sensitivity testing and regional subgroup analysis was used to resolve heterogeneity.

RESULTS

The analysis included 139,485 participants. Clipping demonstrated significantly higher complete occlusion rates in midterm follow-up (RR = 0.83, 95% CI [0.75, 0.91], p = 0.0001) but was associated with a higher risk of procedural complications such as bleeding and ischemic stroke. Coiling showed a higher risk of retreatment (RR = 3.46, 95% CI [1.21, 9.86], p = 0.02), yet it had lower procedural complications (RR = 0.54, 95% CI [0.38, 0.78], p < 0.0009), shorter hospital stays (MD 4.36, 95% CI [2.96, 5.77], p = 0.0001), and better post-procedural outcomes as indicated by lower modified Rankin Scale scores (RR = 0.73, 95% CI [0.55, 0.97], p = 0.03). Long-term occlusion rates were comparable between the two methods.

CONCLUSION

While clipping achieves higher mid-term occlusion rates, coiling is associated with fewer complication rates, shorter hospital stays, and potentially better long-term outcomes. Treatment decisions should be individualized, considering patient-specific characteristics and procedural feasibility.

Intracranial Aneurysms in Autosomal Dominant Polycystic Kidney Disease: A Practical Approach to Screening and Management

Autosomal dominant polycystic kidney disease (ADPKD), the most prevalent genetic kidney disorder, is characterized by diffuse kidney cysts, hypertension, and progressive kidney function decline, often leading to kidney failure by the age of 60 years. Compared with the general population, patients with ADPKD have an increased risk for development of saccular intracranial aneurysms (IAs), which can lead to intracranial bleeding and result in significant disability and mortality. Of both modifiable and nonmodifiable risk factors, the most significant is a family history of IAs or aneurysm rupture. Other contributing factors include hypertension, cigarette smoking, age, and sex. Most IAs currently detected during screening tests are small and located in the anterior circulation. Intracranial aneurysms can be manifested with thunderclap headache, which may be indicative of subarachnoid hemorrhage. Less commonly, IAs cause symptoms related to mass effect with focal neurologic deficits. Subarachnoid hemorrhage is particularly concerning, given its high case-fatality rate, which remains around 35% despite advances in neurologic care. Therefore, control of risk factors, early detection, and treatment when indicated are important to prevent adverse outcomes. Screening for IAs in ADPKD remains controversial and can be approached either universally (screening of all ADPKD patients) or selectively (screening of high-risk patients). The preferred imaging modality is brain magnetic resonance angiography without contrast enhancement or alternatively computed tomography angiography. This review provides a practical guide for medical teams managing patients with ADPKD, detailing the characteristics of IAs and their associated symptoms. It presents an algorithm for risk assessment and screening along with recommendations for treatment and follow-up care.

The value of dual-energy computed tomography angiography-based virtual monoenergetic imaging for evaluations after cerebral aneurysm clipping

PURPOSE

This study aimed to research the optimal energy range of dual-energy computed tomography angiography (DECTA)-based virtual monoenergetic imaging (VMI) for evaluations after cerebral aneurysm clipping.

METHODS

Sixty patients who underwent DECTA after cerebral aneurysm clipping were analyzed retrospectively. Conventional computed tomography angiography (CTA) was compared with VMIs at 60, 70, 80, 90, and 100 keV. The mean attenuation and standard deviation values within the regions of interest placed in the brain parenchyma and arteries with the worst artifact were measured, respectively. The ΔCT and artifact index (AI) values were calculated to assess the artifact severity. The contrast-to-noise ratio (CNR) was calculated to assess vascular contrast. Two radiologists assessed brain parenchyma and cerebrovascular scores qualitatively using a five-point Likert scale.

RESULTS

Quantitative analysis showed that the artifacts of VMIs were significantly reduced compared with conventional CTA (P ≤ 0.014), except for the ΔCT and AI of 60 keV and the ΔCT of 70 keV. However, there was no significant difference in the vascular contrast on VMIs compared with conventional CTA, except for the CNR of 60 keV (P = 0.008). In qualitative analysis, the proportions of brain parenchyma scores and cerebrovascular scores ≥4 on the VMIs of 70 and 80 keV were higher than those of conventional CTA and other VMIs.

CONCLUSION

For the patients who underwent DECTA after cerebral aneurysm clipping, the 70-80 keV VMIs are expected to be the optimal energy range for balancing clip artifacts and visibility of adjacent vessels.

CLINICAL SIGNIFICANCE

Studying the optimal energy range of DECTA-based VMI for post-operative assessment of aneurysm clipping can reduce metal artifacts in images and increase vascular contrast. This facilitates the follow-up of patients after aneurysm clipping, offers timely and accurate detection of postoperative complications, provides assistance to clinicians in diagnosis and treatment, and improves patient prognosis.

Two-Sample Mendelian Randomization Analyses Identified Lipid Species Associated With Intracranial Aneurysm Formation

OBJECTIVES

Intracranial aneurysm (IA) poses a significant health risk, and its formation involves various factors, including lipid metabolism, while former research only focused on the standard lipid. The purpose of this study is to explore 179 lipid variants' impact on unruptured intracranial aneurysms (uIA).

MATERIALS AND METHODS

Utilizing GWAS data for lipids and uIAs, MR analyses were employed with pleiotropy, heterogeneity, and sensitivity tests. Reverse MR analyses were then conducted.

RESULTS

MR analyses revealed seven lipids associated with uIAs: TAG (51:3). SE (27:1/16:1), PC (18:2_18:2), TAG (48:1), TAG (48:2), and TAG (51:3) were identified as uIA risk factors, while SE (27:1/18:1) and SM (d34:0) exhibited protective effects. Reverse MR analysis showed no bidirectional causal relationships.

CONCLUSIONS

This study identifies specific lipid variants causally linked to uIAs, shedding light on their roles in IA formation. These findings contribute to future research on IA risk assessment and potential therapeutic interventions.

Irregular pulsation on 4D-CTA and quantitative wall enhancement on VW-MRI are associated with symptoms of unruptured intracranial aneurysms

BACKGROUND

Unruptured intracranial aneurysms (IAs) that become symptomatic have been associated with instability.

OBJECTIVE

To investigate the relationship between irregular pulsation on four-dimensional CT angiography (4D-CTA) and aneurysm wall enhancement (AWE) on vessel wall MRI (VW-MRI), and to evaluate their ability to identify symptomatic IAs.

METHODS

This retrospective study included consecutive patients with IAs who underwent 4D-CTA and VW-MRI between March 2018 and May 2023. IAs were categorized as asymptomatic and symptomatic. The presence of irregular pulsation was identified on 4D-CTA video. Qualitative and quantitative AWE were evaluated. Univariate and multivariate analyses were used to identify the parameters associated with symptoms.

RESULTS

192 patients with 216 aneurysms (167 asymptomatic and 49 symptomatic) were included. IAs with irregular pulsation had significantly higher wall enhancement index (WEI) than IAs without irregular pulsation (median (IQR), 0.5 (0.2-1.1) vs 0.2 (0.0-0.6), P<0.001). Symptomatic IAs had significantly higher WEI than asymptomatic IAs (median (IQR), 0.7 (0.3-1.5) vs 0.2 (0.0-0.5), P<0.001), and more irregular pulsations (79.6% vs 25.1%, P<0.001). Both irregular pulsation (OR=6.86; 95% CI 2.62 to 17.96; P<0.001) and WEI (OR=2.56; 95% CI 1.14 to 5.71; P=0.022) were independently associated with symptoms. Combination of irregular pulsation and WEI achieved the highest area under the curve of 0.86 in identifying symptomatic aneurysms compared with irregular pulsation or WEI alone (P<0.001 and P=0.002, respectively).

CONCLUSION

In a large cohort of patients with unruptured IAs who underwent 4D-CTA and VW-MRI, both irregular pulsation and WEI were independently associated with symptoms. Such measures could identify IAs at higher risk of growth or rupture.

Serum Interleukin-1 Levels Are Associated with Intracranial Aneurysm Instability

Serum interleukin-1 (IL-1) are possibly indicative of the inflammation in the intracranial aneurysm (IA) wall. This study aimed to investigate whether IL-1 could discriminate the unstable IAs (ruptured intracranial aneurysms (RIAs) and symptomatic unruptured intracranial aneurysms (UIAs)) from stable, asymptomatic UIAs. IA tissues and blood samples from 35 RIA patients and 35 UIA patients were collected between January 2017 and June 2020 as the derivation cohort. Blood samples from 211 patients with UIAs were collected between January 2021 and June 2022 as the validation cohort (including 63 symptomatic UIAs). Blood samples from 35 non-cerebral-edema meningioma patients (non-inflammatory control) and 19 patients with unknown-cause subarachnoid hemorrhage (hemorrhagic control) were also collected. IL-1β and IL-1.ra (IL-1 receptor antagonist) were measured in serum and IA tissues, and the IL-1 ratio was calculated as log10 (IL-1.ra/IL-1β). Based on the derivation cohort, multivariate logistic analysis showed that IL-1β (odds ratio, 1.48, P = 0.001) and IL-1.ra (odds ratio, 0.74, P = 0.005) were associated with RIAs. The IL-1 ratio showed an excellent diagnostic accuracy for RIAs (c-statistic, 0.91). Histological analysis confirmed the significant correlation of IL-1 between serum and aneurysm tissues. IL-1 ratio could discriminate UIAs from non-inflammatory controls (c-statistic, 0.84), and RIAs from hemorrhagic controls (c-statistic, 0.95). Based on the validation cohort, the combination of IL-1 ratio and PHASES score had better diagnostic accuracy for symptomatic UIAs than PHASES score alone (c-statistic, 0.88 vs 0.80, P < 0.001). Serum IL-1 levels correlate with aneurysm tissue IL-1 levels and unstable aneurysm status, and could serve as a potential biomarker for IA instability.

Glypican-1 may be a plasma biomarker for predicting the rupture of small intracranial aneurysms

Currently, there are no effective methods for predicting the rupture of asymptomatic small intracranial aneurysms (IA) (<7 mm). In this study the aim was to identify early warning biomarkers in peripheral plasma for predicting IA rupture. Four experimental groups were included: ruptured intracranial aneurysm (RIA), unruptured intracranial aneurysm (UIA), traumatic subarachnoid hemorrhage control (tSAHC), and healthy control (HC) groups. Plasma proteomics of these four groups were detected using iTRAQ combined LC-MS/MS. Differentially expressed proteins (DEPs) were identified in RIA, UIA, tSAHC compared with HC. Target proteins associated with aneurysm rupture were obtained by comparing the DEPs of the RIA and UIA groups after filtering out the DEPs of the tSAHC group. The plasma concentrations of target proteins were validated using enzyme-linked immunosorbent assay (ELISA). The iTRAQ analysis showed a significant increase in plasma GPC1 concentration in the RIA group compared to the UIA group, which was further validated among the IA patients. Logistic regression analysis identified GPC1 as an independent risk factor for predicting aneurysm rupture. The ROC curve indicated that the GPC1 plasma cut-off value for predicting aneurysms rupture was 4.99 ng/ml. GPC1 may be an early warning biomarker for predicting the rupture of small intracranial aneurysms. SIGNIFICANCE: The current management approach for asymptomatic small intracranial aneurysms (<7 mm) is limited to conservative observation and surgical intervention. However, the decision-making process regarding these options poses a dilemma due to weighing their respective advantages and disadvantages. Currently, there is a lack of effective diagnostic methods to predict the rupture of small aneurysms. Therefore, our aim is to identify early warning biomarkers in peripheral plasma that can serve as quantitative detection markers for predicting intracranial aneurysm rupture. In this study, four experimental populations were established: small ruptured intracranial aneurysm (sRIA) group, small unruptured intracranial aneurysm (sUIA) group, traumatic subarachnoid hemorrhage control (tSAHC) group, and healthy control (HC) group. The tSAH group was the control group of spontaneous subarachnoid hemorrhage caused by ruptured aneurysm. Compared with patients with UIA, aneurysm tissue and plasma GPC1 in patients with RIA is significantly higher, and GPC1 may be an early warning biomarker for predicting the rupture of intracranial small aneurysms.

Neutrophil-to-lymphocyte ratio associated with symptomatic saccular unruptured intracranial aneurysm

BACKGROUND AND PURPOSE

Whether symptomatic unruptured intracranial aneurysms (UIAs) lead to change in circulating inflammation remains unclear. This study aims to evaluate the role of hematological inflammatory indicators in predicting symptomatic UIA.

METHODS

Adult patients diagnosed with saccular intracranial aneurysm from March 2019 to September 2023 were recruited retrospectively. Clinical and laboratory data, including the white blood cells (WBC), neutral counts (NEUT), lymphocyte counts (LYM), and monocyte counts (MONO) of each patient, were collected. The neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) were calculated as NLR = NEUT/LYM, LMR = LYM/MONO, SII = PLT*NEUT/LYM. The hematological inflammatory indicators were compared in symptomatic saccular and asymptomatic UIA patients. Multivariable logistic regression analyses were performed to explore the factors predicting symptomatic UIA.

RESULTS

One hundred and fifty UIA patients with a mean age of 58.5 ± 12.4 were included, of which 68% were females. The NLR and LMR were significantly associated with symptomatic UIA, and the association remained in small UIAs (< 7 mm). The multiple logistic regression analysis showed that NLR was independently associated with symptomatic UIA. On ROC curve analysis, the optimal cutoff value of NLR to differentiate symptomatic from asymptomatic was 2.38. In addition, LMR was significantly associated with symptomatic UIA smaller than 7 mm.

CONCLUSION

There was a significant correlation between NLR and symptomatic UIA. The NLR was independently associated with symptomatic UIA.

Coiling Variations for Treatment of Ruptured Intracranial Aneurysms: A Meta-Analytical Comparison of Comaneci-, Stent-, and Balloon-Coiling Assistance Techniques

BACKGROUND

Wide-necked aneurysms represent a challenge for treatment in the setting of acute subarachnoid hemorrhage. Stent-assisted coiling (SAC) and balloon-assisted coiling (BAC) are well-known techniques for treating wide-necked aneurysms. Comaneci-assisted coiling (CAC) is a newer technique involving temporary stent deployment to assist aneurysm coiling. We aim to present the first meta-analysis comparing these treatments of ruptured aneurysms.

METHODS

Following PRISMA guidelines, PubMed and Embase databases were queried from earliest records to July 2022 for literature reporting SAC, BAC, or CAC of ruptured intracranial aneurysms. A meta-analysis of identified articles was performed.

RESULTS

Of the 571 articles queried, 64 articles were included. One study reported BAC and SAC, 8 reported BAC, 52 reported SAC, and 3 reported CAC. These studies comprised 3153 patients with 3207 ruptured aneurysms treated with CAC (161 patients and aneurysms), BAC (330 patients and aneurysms), and SAC (2662 patients, 2716 aneurysms). Rates of periprocedural thromboembolic or hemorrhagic complications, overall or procedure-related mortality, immediate complete occlusion, retreatment, and length of angiographic follow-up did not differ significantly between SAC and BAC. Periprocedural thromboembolic (P = 0.03) and hemorrhagic (P = 0.01) complication rates were higher with BAC than CAC. Periprocedural thromboembolic (P = 0.03) and hemorrhagic (P < 0.0001) complication rates were higher with SAC than CAC. Complete aneurysm occlusion rates (P = 0.033) were higher with CAC than BAC. No significant differences were present in CAC versus BAC or SAC retreatment rates.

CONCLUSIONS

CAC was associated with lower hemorrhagic and thromboembolic complication rates and demonstrated similar complete occlusion and residual retreatment rates to those for BAC and SAC.

3D-Printed Head Model in Patient's Education for Micro-Neurosurgical Aneurysm Clipping Procedures

BACKGROUND

Computed tomography (CT), Magnetic resonance imaging (MRI), and 3D reconstruction from Digital Subtraction Angiography (DSA) are currently used in clinical consultations for patients diagnosed with intracranial aneurysms; however, they have limitations in helping patients understand the disease and possible treatments. This study investigates the use of a 3D-printed model of the patients' neurosurgical anatomy and vascular pathology as an educational tool in outpatient clinics.

METHODS

A 3D-printed model of a middle cerebral artery aneurysm was created for use during patient consultations to discuss microsurgical treatment of unruptured cerebral aneurysms. In total, 38 patients and 5 neurosurgeons were included in the study. After the consultation, the patients and neurosurgeons received a questionnaire to assess the effectiveness of the 3D-printed model as an educational tool.

RESULTS

The 3D model improved the patients' understanding of the diagnosis, the aneurysm's relationship to the parent artery; the treatment process as well as the risks if left untreated. The patients found the 3D model to be an interesting tool (97%). The neurosurgeons were satisfied with the 3D-printed model as a patient encounter tool, they found the model effective during consultation (87%) and better than the conventional education tools used during consultations (97%).

CONCLUSIONS

Using a 3D model improves communication, enhances the patient's understanding of the pathology and its treatment and potentially facilitates the informed consent process in patients undergoing intracranial aneurysm surgery.

A comprehensive assessment of self-reported symptoms among patients harboring an unruptured intracranial aneurysm

Background

Approximately 3.2%-6% of the general population harbor an unruptured intracranial aneurysm (UIA). Ruptured aneurysms represent a significant healthcare burden, and preventing rupture relies on early detection and treatment. Most patients with UIAs are asymptomatic, and many of the symptoms associated with UIAs are nonspecific, which makes diagnosis challenging. This study explored symptoms associated with UIAs, the rate of resolution of such symptoms after microsurgical treatment, and the likely pathophysiology.

Methods

A retrospective review of patients with UIAs who underwent microsurgical treatment from January 1, 2014, to December 31, 2020, at a single quaternary center were identified. Analyses included the prevalence of nonspecific symptoms upon clinical presentation and postoperative follow-up; comparisons of symptomatology by aneurysmal location; and comparisons of patient demographics, aneurysmal characteristics, and poor neurologic outcome at postoperative follow-up stratified by symptomatic versus asymptomatic presentation.

Results

The analysis included 454 patients; 350 (77%) were symptomatic. The most common presenting symptom among all 454 patients was headache (n = 211 [46%]), followed by vertigo (n = 94 [21%]), cognitive disturbance (n = 68[15%]), and visual disturbance (n = 64 [14%]). Among 328 patients assessed for postoperative symptoms, 258 (79%) experienced symptom resolution or improvement.

Conclusion

This cohort demonstrates that the clinical presentation of patients with UIAs can be associated with vague and nonspecific symptoms. Early detection is crucial to prevent aneurysmal subarachnoid hemorrhage. It is imperative that physicians not rule out aneurysms in the setting of nonspecific neurologic symptoms.

Irregular pulsation of aneurysmal wall is associated with symptomatic and ruptured intracranial aneurysms

BACKGROUND

Irregular pulsation of aneurysmal wall detected by four-dimensional CT angiography (4D-CTA) has been described as a novel imaging feature of aneurysm vulnerability. Our study aimed to investigate whether irregular pulsation is associated with symptomatic and ruptured intracranial aneurysms (IAs).

METHODS

This retrospective study included consecutive patients with IAs who underwent 4D-CTA from January 2018 to July 2021. IAs were categorized as asymptomatic, symptomatic or ruptured. The presence of irregular pulsation (defined as a temporary focal protuberance ≥1 mm on more than three successive frames) was identified on 4D-CTA movies. Univariate and multivariate analyses were used to identify the parameters associated with aneurysm symptomatic or ruptured status.

RESULTS

Overall, 305 patients with 328 aneurysms (37 ruptured, 60 symptomatic, 231 asymptomatic) were included. Ruptured and symptomatic IAs were significantly larger in size compared with asymptomatic IAs (median (IQR) 6.5 (5.1-8.3) mm, 7.0 (5.5-9.7) mm vs 4.7 (3.8-6.3) mm, p=0.001 and p<0.001, respectively) and had more irregular pulsations (70.3%, 78.3% vs 28.1%, p<0.05). Irregular pulsation (OR 5.03, 95% CI 2.83 to 8.92; p<0.001) was independently associated with aneurysm symptomatic/ruptured status in the whole population. With unruptured IAs, both irregular pulsation (OR 6.31, 95% CI 3.02 to 13.20; p<0.001) and size (OR 1.17, 95% CI 1.03 to 1.32; p=0.015) were independently associated with the symptoms. The combination of irregular pulsation and size increased the accuracy over size alone in identifying symptomatic aneurysms (AUC 0.81 vs 0.77, p=0.007) in unruptured IAs.

CONCLUSION

In a large cohort of patients with IAs detected by 4D-CTA, the presence of irregular pulsation was independently associated with aneurysm symptomatic and ruptured status.

Qualitative and quantitative wall enhancement associated with unstable intracranial aneurysms: a meta-analysis

Background

Unstable intracranial aneurysms (UIAs) are more likely to rupture and cause serious consequences. Evaluating the stability of unruptured aneurysms facilitates clinical management stratification.

Purpose

To compare and evaluate the predictive performance of qualitative and quantitative wall enhancement (aneurysmal wall enhancement [AWE], circumferential aneurysmal wall enhancement [CAWE], wall enhancement ratio [WER]) on high-resolution magnetic resonance imaging (MRI) of the vessel wall to predict the presence of UIA.

Material and Methods

Original articles describing the depiction of aneurysmal wall enhancement on 3.0-T or 1.5-T high-resolution vessel wall imaging were retrieved from the Web of Science, Medline/PubMed, the Cochrane Library, and EMBASE databases up to 15 February 2022. The combined sensitivity, specificity, and summary area under the receiver operating characteristic curve (AUC) were calculated, and meta-regression analysis was performed.

Results

In total, 12 original articles involving 1619 intracranial aneurysms (IAs) were included. The combined sensitivity and specificity of AWE, CAWE, and WER were 91% and 67%, 59% and 83%, and 86% and 75%, respectively, in the diagnosis of UIA. The summary AUC values of these items were, in order from high to low, 0.88 (WER), 0.84 (AWE), and 0.77 (CAWE), and the differences among them were significant ( z = 2.976, P = 0.003 and z = 2.950, P = 0.003). The meta-regression analysis identified average size and 2D/3D magnetic imaging technology as possible sources of heterogeneity.

Conclusion

Qualitative and quantitative wall enhancement showed moderate accuracy in predicting UIA, and WER had the highest accuracy among them in this meta-analysis. Two covariates were found to explain the heterogeneity.

Transient Ischemic Attack Due to Unruptured Basilar Artery Aneurysm

Intracranial aneurysms are typically asymptomatic. They are usually incidentally detected or detected only after rupture. Ischemic stroke or transient ischemic attack (TIA) due to unruptured intracranial aneurysms (UIAs) is rare. A 79-year-old male with well-controlled hypertension and hypothyroidism, presented with complaints of sudden-onset weakness of the right upper limb and lower limb, followed by altered sensorium and a fall. Two hours later, he had fully recovered. Neurologic examination was unremarkable. Computed tomography of the brain revealed a dilated and tortuous basilar artery, suggestive of an aneurysm compressing the left midbrain and pons, with no evidence of intracranial bleed. Further, magnetic resonance imaging with an angiogram revealed multiple lacunar infarcts in the posterior circulation, distal to the aneurysm. Finally, a cerebral angiogram confirmed a partially thrombosed, fusosaccular aneurysm, arising from the left vertebral and basilar arteries. In view of frailty and long vessel segment involvement, surgery was not advised. He was treated medically, with appropriate antiplatelets and prophylactic antiepileptics. On follow-up, he had no neurologic deficit and had suffered no later ischemic or hemorrhagic events. UIAs may cause brainstem strokes via thrombosis of the parent vessel, emboli from the thrombus, or compression of the parent artery. In our case, compression, the least common mechanism, appears to have caused the TIA, with emboli potentially responsible for the silent lacunar infarcts. Fusiform aneurysms of the vertebrobasilar system have a poor natural history. In elderly patients presenting with ischemic events due to UIAs of the vertebrobasilar system, surgical intervention can be risky. So, medical treatment with antiplatelets is recommended. UIAs should be considered in the differential diagnosis of patients with TIAs, and such patients should have a visualization of intracranial arteries.

Subarachnoid Hemorrhage Induces Sub-acute and Early Chronic Impairment in Learning and Memory in Mice

Subarachnoid hemorrhage (SAH) leads to significant long-term cognitive deficits, so-called the post-SAH syndrome. Existing neurological scales used to assess outcomes of SAH are focused on sensory-motor functions. To better evaluate short-term and chronic consequences of SAH, we explored and validated a battery of neurobehavioral tests to gauge the functional outcomes in mice after the circle of Willis perforation-induced SAH. The 18-point Garcia scale, applied up to 4 days, detected impairment only at 24-h time point and showed no significant difference between the Sham and SAH group. A decrease in locomotion was detected at 4-days post-surgery in the open field test but recovered at 30 days in Sham and SAH groups. However, an anxiety-like behavior undetected at 4 days developed at 30 days in SAH mice. At 4-days post-surgery, Y-maze revealed an impairment in working spatial memory in SAH mice, and dyadic social interactions showed a decrease in the sociability in SAH mice, which spent less time interacting with the stimulus mouse. At 30 days after ictus, SAH mice displayed mild spatial learning and memory deficits in the Barnes maze as they committed significantly more errors and used more time to find the escape box but still were able to learn the task. We also observed cognitive dysfunction in the SAH mice in the novel object recognition test. Taken together, these data suggest dysfunction of the limbic system and hippocampus in particular. We suggest a battery of 5 basic behavioral tests allowing to detect neurocognitive deficits in a sub-acute and chronic phase following the SAH.

Irregular pulsation of intracranial unruptured aneurysm detected by four-dimensional CT angiography is associated with increased estimated rupture risk and conventional risk factors

BACKGROUND

Intracranial aneurysms (IAs) are common in the population and current imaging-based rupture risk assessment needs to be refined. We aimed to use four-dimensional CT angiography (4D-CTA) to investigate the associations of irregular pulsation of IAs with conventional risk factors and the estimated rupture risk.

METHODS

One hundred and five patients with 117 asymptomatic IAs underwent 4D-CTA. Geometric and morphologic parameters were measured and the presence of irregular pulsation (defined as a temporary focal protuberance ≥1 mm on more than three successive frames) was identified on 4D-CTA movies. One- and 5 year aneurysm rupture risk were estimated using UCAS and PHASES calculators. Univariate and multivariate analyses were performed to investigate the conventional risk factors associated with irregular pulsation.

RESULTS

Irregular pulsation was observed in 41.0% (48/117) of IAs. Aneurysm size (OR=1.380, 95% CI 1.165 to 1.634), irregular shape (OR=3.737, 95% CI 1.108 to 12.608), and internal carotid artery location (OR=0.151, 95% CI 0.056 to 0.403) were independently associated with irregular pulsation (P<0.05). Aneurysms with irregular pulsation had more than a 6-fold higher estimated rupture risk (1- and 5-year risk [95% CI], 1.56% [0.42%-3.91%], and 2.40% [1.30%-4.30%], respectively) than aneurysms without irregular pulsation (0.23% [0.14%-0.78%] and 0.40% [0.40%-1.30%], respectively) (P<0.001).

CONCLUSIONS

IAs with irregular pulsation are associated with larger size, irregular-shape, and non-ICA origin, and have more than a 6-fold higher estimated 1- and 5-year rupture risk than aneurysms without irregular pulsation. Irregular pulsation should be validated in future longitudinal studies to determine its predictive value for aneurysm growth and rupture.

Qualitative and Quantitative Wall Enhancement on Magnetic Resonance Imaging Is Associated With Symptoms of Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

Aneurysmal wall enhancement (AWE) on vessel wall magnetic resonance imaging (VW-MRI) has been described as a new imaging biomarker of unstable unruptured intracranial aneurysms (UIAs). Previous studies of symptomatic UIAs are limited due to small sample sizes and lack of AWE quantification. Our study aims to investigate whether qualitative and quantitative assessment of AWE can differentiate symptomatic and asymptomatic UIAs.

METHODS

Consecutive patients with UIAs were prospectively recruited for vessel wall magnetic resonance imaging at 3T from October 2014 to October 2019. UIAs were categorized as symptomatic if presenting with sentinel headache or oculomotor nerve palsy directly related to the aneurysm. Evaluation of wall enhancement included enhancement pattern (0=none, 1=focal, and 2=circumferential) and quantitative wall enhancement index (WEI). Univariate and multivariate analyses were used to identify the parameters associated with symptoms.

RESULTS

Two hundred sixty-seven patients with 341 UIAs (93 symptomatic and 248 asymptomatic) were included in this study. Symptomatic UIAs more frequently showed circumferential AWE than asymptomatic UIAs (66.7% versus 17.3%, P<0.001), as well as higher WEI (median [interquartile range], 1.3 [1.0-1.9] versus 0.3 [0.1-0.9], P<0.001). In multivariate analysis, both AWE pattern and WEI were independent factors associated with symptoms (odds ratio=2.03 across AWE patterns [95% CI, 1.21-3.39], P=0.01; odds ratio=3.32 for WEI [95% CI, 1.51-7.26], P=0.003). The combination of AWE pattern and WEI had an area under the curve of 0.91 to identify symptomatic UIAs, with a sensitivity of 95.7% and a specificity of 73.4%.

CONCLUSIONS

In a large cohort of UIAs with vessel wall magnetic resonance imaging, both AWE pattern and WEI were independently associated with aneurysm-related symptoms. The qualitative and quantitative features of AWE can potentially be used to identify unstable intracranial aneurysms.

Neurovascular disease, diagnosis, and therapy: Brain aneurysms

Unruptured intracranial aneurysms (UIAs) have a prevalence of 3% in the adult population worldwide. The majority of UIAs are incidental findings, but some UIAs cause cranial nerve palsies, brainstem compression, ischemic events, or epileptic seizures. The most frequent clinical presentation of intracranial aneurysms is, however, rupture and thereby subarachnoid hemorrhage (SAH). To avoid SAH with its fatal consequences, patients with UIAs require counseling by dedicated and interdisciplinary neurovascular specialists. For the purpose of assessment and decision-making for the management of patients with UIAs, numerous aspects have to be considered: radiological characteristics, clinical symptoms, estimated rupture risk of an individual aneurysm as well as patient- and aneurysm-related risks of preventive repair. Generally, two management options exist: observation with follow-up imaging or preventive repair. This chapter discusses current data on pathogenesis, clinical presentation, diagnostics, risk factors for rupture and preventive repair, and guidance tools for the management of patients with UIAs according to current evidence.

Acute non-traumatic subdural hematoma induced by intracranial aneurysm rupture: A case report and systematic review of the literature

RATIONALE

Intracranial aneurysm with the first manifestation of acute subdural hematoma (aSDH) is rare in the field of neurosurgery. Usually subarachnoid hemorrhage or intracranial hematoma happens after the rupture of an intracranial aneurysm, whereas trauma is the primary cause of aSDH.

PATIENT CONCERNS

Here, we present the case of a 71-year-old woman who presented with spontaneous aSDH with progressive headache and vomiting.

DIAGNOSIS

Urgent head computed tomography (CT) identified an aSHD, but the patient had no history of trauma. CT angiography (CTA) identified the cause of the aSDH as rupture of an intracranial aneurysm in the left middle cerebral artery.

INTERVENTIONS

Emergent craniotomy with hematoma evacuation was performed.

OUTCOMES

Due to prompt diagnosis and appropriate intervention, the patient recovered fully with no disability.

LESSONS

This unique case demonstrates that aSDH caused by intracranial aneurysm rupture requires timely identification and appropriate action to prevent adverse outcomes. We performed a comprehensive systematic literature review to examine the etiology and pathogenesis of non-traumatic aSDH. Furthermore, digital subtraction angiography should be considered in patients diagnosed with an aSDH with no known cause.

Wall enhancement on black-blood MRI is independently associated with symptomatic status of unruptured intracranial saccular aneurysm

OBJECTIVE

This study aims to investigate whether aneurysm wall enhancement (AWE) is independently associated with symptomatic status of unruptured intracranial aneurysms (UIAs).

METHODS

One hundred thirty-nine consecutive patients (67 male, mean age 58 ± 11 years) with 79 symptomatic and 87 asymptomatic UIAs were imaged using black-blood MRI pre- and post-gadolinium contrast administration and 3D DSA. Symptoms related to aneurysms were identified including cranial nerve deficits and headache. AWE grade and area were characterized, and aneurysm size was measured on DSA. Multivariate binary logistic regression analysis was used to identify factors associated with symptoms. Further subgroup analysis was performed for aneurysms size < 10 mm.

RESULTS

Symptomatic UIAs had significantly larger aneurysm size (11.2 ± 6.2 mm vs. 6.4 ± 3.3 mm), enhancement grade (1.3 ± 0.6 vs. 0.4 ± 0.6), enhancement area (2.0 ± 0.9 vs. 0.4 ± 0.7), and higher prevalence of thick enhancement (39% vs. 3%) compared with asymptomatic UIAs, all p < 0.001. In multivariate analysis, only AWE area (odds ratio [OR] 6.9, 95% confidence interval [4.0, 11.7]) was independently associated with symptoms. AWE area had an area under curve (AUC) value of 0.888, with 72.2% sensitivity and 92.0% specificity for symptoms, which was superior to aneurysm size (AUC of 0.771, with 75.9% sensitivity and 65.5% specificity). In the subgroup analysis of aneurysms smaller than 10 mm (n = 118), AWE area (OR, 7.0, p < 0.001) remained the only independent risk factor associated with symptoms.

CONCLUSIONS

Larger AWE area is independently associated with symptomatic UIAs, which may provide additional value to guide UIA management and improve patient outcomes.

KEY POINTS

• Symptomatic intracranial aneurysms are larger and more often demonstrate significant wall enhancement than asymptomatic aneurysms. • Larger wall enhancement area is independently associated with symptomatic intracranial aneurysm.

Ruptured aneurysm in the posterior communicating segment of carotid artery presenting with contralateral oculomotor nerve palsy

Background:

Brain aneurysms are mostly discovered during the investigation of subarachnoid hemorrhage (SAH). Some patients present neurological signs that may suggest the aneurysm’s topography, and the oculomotor nerve palsy (ONP) of the same side of the aneurysm is the most common sign. Only one case report of contralateral palsy was previously described in the medical literature.

Case Description:

Authors describe a patient who presented a classic manifestation of SAH associated with complete ONP, whose vascular investigation demonstrated a brain aneurysm located in the contralateral intracranial carotid. The patient was surgically treated with great neurologic outcome, and late angiography did not evidence other vascular abnormalities.

Conclusion:

The ipsilateral ONP is a common sign found in posterior communicating artery aneurysms; however, such aneurysm can have different presentations due to the elevation of intracranial pressure, and, in rarer cases, the ONP cannot be operated as a localizing sign.

Wall enhancement of intracranial saccular and fusiform aneurysms may differ in intensity and extension: a pilot study using 7-T high-resolution black-blood MRI

PURPOSE

To evaluate and compare wall enhancement patterns in saccular and fusiform intracranial aneurysms using high-resolution black-blood MRI at 7 T.

METHODS

Thirty-one patients with 32 unruptured intracranial aneurysms (21 saccular and 11 fusiform) underwent 7-T black-blood MRI. Aneurysm wall enhancement (AWE) was categorized as follows: no wall enhancement (NWE), focal wall enhancement (FWE), and uniform wall enhancement (UWE). The degree of enhancement was scored as follows: 0 (no enhancement), 1 (signal intensity (SI) of the aneurysm wall less than that of the pituitary infundibulum), and 2 (equal to that of the pituitary infundibulum). The chi-squared test was used to compare the AWE pattern and degree between saccular and fusiform aneurysms.

RESULTS

In saccular aneurysms, 12/21 (57%) enhanced. Of these, 9 showed FWE (5 grade 1 and 4 grade 2), and 3 showed UWE (2 grade 1 and 1 grade 2). In fusiform aneurysms, 11/11 (100%) enhanced. Of these, 1 showed FWE and 10 showed UWE. All fusiform aneurysms had grade-2 enhancement. Fusiform aneurysms had more extensive and higher SI AWE than saccular aneurysms (p < 0.01) despite having a similar size (6.9 ± 3.0 mm vs. 8.0 ± 2.9, p = 0.23). For saccular aneurysm, larger aneurysm size was correlated with higher degree of enhancement with Pearson's r = 0.64 (p = 0.002).

CONCLUSION

Intracranial fusiform aneurysms had enhancement of higher SI and that covered a more extensive area than saccular aneurysms, which might indicate differences in vessel wall pathology.

KEY POINTS

• Intracranial aneurysm wall enhancement can be reliably characterized by 7-T black-blood MRI. • AWE in intracranial fusiform aneurysms presents over a larger surface area and with greater signal intensity as compared with that in saccular aneurysms, which might indicate differences in pathology. • Stronger signal intensity of AWE correlates with the aneurysm size in saccular aneurysms.

Clinical Significance of Circumferential Aneurysmal Wall Enhancement in Symptomatic Patients with Unruptured Intracranial Aneurysms: a High-resolution MRI Study

BACKGROUND AND PURPOSE

The estimates on the risk of rupture of intracranial aneurysms remain a controversial topic. Circumferential aneurysmal wall enhancement (CAWE) on vessel wall magnetic resonance imaging (MRI) has been described in unstable aneurysms. Sentinel headaches and third nerve palsy are possible symptoms prior to the rupture of intracranial aneurysms. In this study, we aimed to demonstrate that CAWE could be associated with these symptoms.

METHODS

We performed a retrospective analysis of consecutive symptomatic or asymptomatic patients with unruptured intracranial aneurysms who were examined by high-resolution MRI from October 2014 to November 2016. Two experienced neurovascular radiologists read the images independently and determined whether there was CAWE of the unruptured intracranial aneurysms. Then, we compared variable factors between patients with and without symptoms through univariate comparison and multivariable logistic regression analyses.

RESULTS

A total of 45 unruptured intracranial aneurysms were detected in 37 patients. The agreement between 2 experienced readers for CAWE was good (kappa = 0.82; 95% confidence interval 0.66-0.99). CAWE of unruptured intracranial aneurysm was more frequently observed in symptomatic than in asymptomatic patients (16/23, 69.6% versus 6/22, 27.3%, respectively, P < 0.05). The CAWE was the only independent factor associated with symptoms in the multivariable logistic regression analysis (odds ratio 5.17; 95% confidence interval 1.30-20.52; P = 0.02).

CONCLUSIONS

Our study demonstrates that CAWE correlated with sentinel headaches and third nerve palsy caused by unruptured aneurysms, and this may be an additional clue to distinguish the cause of these symptoms.

Anterior Optic Pathway Compression Due to Internal Carotid Artery Aneurysms: Neurosurgical Management and Outcomes

Background and Purpose

Compression of the anterior optic pathway results in visual deficits that can lead to the detection of unruptured aneurysms in the internal carotid artery (ICA). The general types of treatment modalities for aneurysms and visual deficits include surgery and endosaccular coiling. This study retrospectively analyzed and compared the resolution of visual deficits following surgery or endosaccular coiling.

Methods

We reviewed data on 33 patients with unruptured ICA aneurysms who presented with visual field deficits caused by mass effects over the anterior optic pathway. Statistical analyses were performed to identify the variables associated with the recovery of visual symptoms.

Results

Eighteen patients underwent aneurysm clipping, 2 underwent bypass surgery with endovascular trapping, and 2 underwent endovascular trapping without bypass surgery (group A). Ten patients received endosaccular coiling (group B). The visual outcomes included the following: in group A, 17 patients (73.9%) demonstrated improvement and 6 patients (26.1%) demonstrated no changes or worse outcomes; in group B, 2 patients (20.0%) demonstrated improvement and 8 patients (80.0%) demonstrated no changes or worse outcomes. Group A was associated with a higher rate of favorable outcome than group B (P = 0.007). According to the multivariate analysis, treatment without endosaccular coiling (group A) was the only variable significantly associated with improvement of visual outcome (P = 0.005; OR = 28.523; 95% CI = 2.683-303.171).

Conclusions

Treatment modality was the only predictor of improvement in visual deficits. Treatment without endosaccular coiling resulted in visual improvement significantly more often in comparison with endosaccular coiling.

Functional response of cerebral blood flow induced by somatosensory stimulation in rats with subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is often accompanied by cerebral vasospasm (CVS), which is the phenomenon of narrowing of large cerebral arteries, and then can produce delayed ischemic neurological deficit (DIND) such as lateralized sensory dysfunction. CVS was regarded as a major contributor to DIND in patients with SAH. However, therapy for preventing vasospasm after SAH to improve the outcomes may not work all the time. It is important to find answers to the relationship between CVS and DIND after SAH. How local cerebral blood flow (CBF) is regulated during functional activation after SAH still remains poorly understood, whereas, the regulation of CBF may play an important role in weakening the impact of CVS on cortex function. Therefore, it is worthwhile to evaluate the functional response of CBF in the activated cortex in an SAH animal model. Most evaluation of the effect of SAH is presently carried out by neurological behavioral scales. The functional imaging of cortical activation during sensory stimulation may help to reflect the function of the somatosensory cortex more locally than the behavioral scales do. We investigated the functional response of CBF in the somatosensory cortex induced by an electrical stimulation to contralateral forepaw via laser speckle imaging in a rat SAH model. Nineteen Sprague-Dawley rats from two groups (control group, n=10 and SAH group, n=9) were studied. SAH was induced in rats by double injection of autologous blood into the cisterna magna after CSF aspiration. The same surgical procedure was applied in the control group without CSF aspiration or blood injection. Significant CVS was found in the SAH group. Meanwhile, we observed a delayed peak of CBF response in rats with SAH compared with those in the control group, whereas no significant difference was found in magnitude, duration, and areas under curve of relative CBF changes between the two groups. The results suggest that the regulation function of local CBF during functional activation induced by somatosensory stimulation might not be seriously impaired in the somatosensory cortex of rats with SAH. Therefore, our findings might help to understand the clinical phenomenon that DIND might not occur even when CVS was found in SAH patients.

Occipital artery-posterior inferior cerebellar artery bypass for the treatment of aneurysms arising from the vertebral artery and its branches

OBJECTIVE

To report experience with 7 cases of intracranial aneurysms of the vertebral artery (VA) and its branches that were treated with occipital artery (OA)-posterior inferior cerebellar artery (PICA) bypass.

METHODS

Over 4 years, 7 cases of intracranial aneurysms arising from the VA and its branches were treated with OA-PICA bypass. The clinical data, characteristics of aneurysms, and results of treatment were analyzed.

RESULTS

There were 4 aneurysms that arose from the VA-PICA junction, 2 aneurysms that occurred at the distal PICA, and 1 aneurysm that occurred at the collateral artery from the distal end of the occluded VA to the ipsilateral PICA. OA-PICA bypass was performed before obliteration of the aneurysms in all patients. Of the 7 aneurysms, 4 were totally obliterated with surgery, 2 were treated with additional endovascular coiling or trapping, and 1 was partially obliterated by surgery and gradually disappeared during the follow-up period. Postoperative angiography revealed that the patency of the grafts was good in 6 patients. In 1 patient with an occluded bypass graft, multiple infarctions developed in the left cerebellum, but the patient had almost fully recovered after rehabilitation.

CONCLUSIONS

OA-PICA bypass with obliteration of the aneurysm is one of the optimal treatments for intracranial aneurysms that occur at the VA and its branches because it can preserve the perforators and distal blood flow from the PICA.