Cavernous malformations of the brainstem: experience with 100 patients

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) for paediatric intracranial cavernous malformations: case series and review of the literature

PURPOSE

Microsurgical resection is the standard for treating intracranial cavernous malformations (CMs), but minimally invasive approaches are gaining popularity, particularly for deep-seated lesions and pediatric patients. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a potential alternative to open surgery. This study aims to evaluate the safety and efficacy of MRgLITT for pediatric cavernomas and review existing literature.

METHODS

A systematic search of MEDLINE (PubMed), Scopus, Embase, and Cochrane databases using terms related to "LITT" and "cavernomas" identified studies reporting MRgLITT outcomes in pediatric patients. Data on demographics, symptoms, lesion characteristics, and outcomes were extracted. A combined database included cases from literature and four treated at our institution, Santobono-Pausilipon Children's Hospital of Naples.

RESULTS

Three studies with eight pediatric cases and four additional institutional cases were analyzed, totaling 12 patients. Outcomes for epilepsy were favorable: two patients achieved Engel class IA, one class IC, and one class II. No recurrences or hemorrhages occurred. Two patients experienced permanent complications-one with partial right superior quadrantanopia and another with unilateral hearing loss.

CONCLUSION

MRgLITT offers comparable outcomes to open surgery with reduced invasiveness, particularly for deep-seated lesions. Advances in thermal monitoring, neurophysiological monitoring, and functional MRI integration could further refine this approach, expanding its applications while minimizing complications in pediatric CMs.

Surgery of brainstem cavernous malformations: surgical nuances and outcomes of a monocentric series of 34 patients

BACKGROUND

Brainstem cavernous malformations (BCM) constitute one of the most controversial and challenging neurological pathologies: both natural course and surgical manipulation can lead to severe neurological symptoms by direct compression or following hemorrhage of this highly eloquent brain region.

METHODS

The vascular section of the prospectively collected neurosurgical database of our center (2011-2023) was retrospectively reviewed, seeking all patients operated on for a sporadic BCM. Clinical, radiological and surgical data, operative records and videos were analyzed by independent reviewers with the assistance of a dedicated neuropsychologist, blinded to the hospital course.

RESULTS

Thirty-four patients aged between 19 and 70 years were identified and considered for analyses, with different brainstem localizations. The clinical onset was hemorrhagic in almost all cases: the average mRS on admission was 2.47 (21 patients ≤ 2). Surgical treatment was performed on average 15.1 weeks after the last bleeding. At hospital discharge, the mean mRS was 3.26 (6 patients ≤ 2). After a mean follow-up of 56.59 weeks, 29 patients (85.3%) presented an improved or stable mRS compared to hospitalization and 5 had a slight worsening (14.7%).

CONCLUSION

Brainstem cavernoma is a rare entity with aggressive features due to the involved eloquence despite of the benign histology itself. Microsurgical resection should be tailored for each patient to the peculiar characteristics of the harbored lesion. Advanced planning techniques reduced morbidity; patients should be centralized in wide caseload hospitals with high specialization in neurovascular pathologies and should receive an appropriate counseling about natural history and risks of interventional treatment.

An Algorithm for the Microsurgical Resection of Cerebellar Cavernomas

BACKGROUND AND OBJECTIVES

Cavernous malformations (CMs) account for 8% to 15% of all cerebrovascular anomalies and pose clinical significance due to their potential to cause symptomatic hemorrhage, seizures, and focal neurological deficits. While the majority of CMs are located supratentorial, the less common posterior fossa, particularly cerebellar CMs (cCMs), pose a unique treatment challenge. This study aims to contribute to the understanding and management of cerebellar CMs, thereby assisting in the decision-making process for clinical interventions in this patient population.

METHODS

We conducted a retrospective analysis of all patients who were treated for CMs from 2010 to 2023 at our tertiary healthcare facility. Patients with cCMs were further analyzed concerning their treatment strategy and functional outcome based on the modified Rankin Scale.

RESULTS

Nine hundred fourteen patients with CMs were treated between 2013 and 2023 at our center. Among these subjects, 6.5% (n = 59) presented with cerebellar lesions. The median age was 54 [37-64] years, and 15 (25.4%) patients showed associated developmental venous anomalies. Nearly half of these patients (49.0%) were surgically treated. Surgical approaches were tailored and individualized to the specific CM location based on a treatment algorithm and encompassed supracerebellar-infratentorial, telovelar, suboccipital transcortical, retrosigmoid transcortical, and retrosigmoidal transhorizontal fissure approaches. Univariate analysis revealed no risk factors concerning postoperative morbidity. The surgically treated patients showed a significant improvement between preoperative and follow-up functional outcomes.

CONCLUSION

cCMs are rare but frequently necessitate surgical intervention. This study enhances the current understanding of cCMs, underscoring the intricate challenges associated with their management. Differentiated algorithms with tailored approaches ensure the optimization of outcomes in the treatment of these challenging lesions.

One-Point Technique in Brainstem Cavernous Malformation Surgery: Evaluation of Approaches and Outcomes From a Different Perspective

BACKGROUND AND OBJECTIVES

Brainstem cavernous malformations (BCMs) are a distinct clinical entity that carry a high risk of patient morbidity because of location and risk of hemorrhage. Surgical management of these lesions requires intimate knowledge of surgical anatomy and skull base approaches. This article is intended to highlight a modern approach for the treatment of BCMs, with an emphasis on the use of the one-point technique to guide resection.

METHODS

We describe a case series of BCMs treated through a variety of skull base approaches, describing our decision-making strategy. We review the concept of the one-point technique focusing on the safest access to the malformation through 2 representative cases and also perform a retrospective review of 32 consecutive patients who underwent BCM resection to present outcomes and the comparison of two-point vs one-point techniques.

RESULTS

Consecutive series of 32 patients in whom the one-point technique was used is presented. In 8 patients (25%), the traditional two-point technique would suggest a different trajectory than the one-point technique. Postoperative MRI confirmed complete resection in 30 patients (95%), and 29 patients (91%) had modified Rankin Scale (0-2) at follow-up. All patients in whom the one-point technique guided a different trajectory had gross total removal of the cavernous malformation, with one patient having long-term new neurological impairment from the surgery. There were no mortalities.

CONCLUSION

Despite surgical advances in recent decades and more widespread understanding of surgical anatomy and safe entry zones, surgical resection of BCMs remains a formidable challenge. While not necessarily the shortest access, the one-point technique offers a safe approach considering all the different modalities in our armamentarium and can be used as part of a strategy to determine the optimal approach to resect BCMs.

Stereotactic radiosurgery (SRS) for patients with brainstem cerebral cavernous malformations (CCMs): an international, multicentric study

Brainstem cerebral cavernous malformations (CCM) are clinically more aggressive compared to superficial CCMs. Due to their location, resection can be challenging, making stereotactic radiosurgery (SRS) an attractive alternative for symptomatic patient. Brainstem CCM patients (n = 170) were treated with Gamma Knife SRS at 11 radiosurgical centers. Hemorrhagic risk reduction, risk factors of post-SRS hemorrhage, and clinical outcomes were retrospectively analyzed. Most patients had a single (165/170 patients) brainstem CCMs treated; the majority of CCMs (165/181) presented with bleeding. Single-session SRS decreased the risk of repeat hemorrhage in patients with hemorrhagic brainstem CCM (HR: 0.17, p < 0.001) using recurrent multivariate analysis. The annual hemorrhage rate decreased from 14.8 per 100 CCM-years before SRS to 2.3 after treatment. Using univariate Cox-analysis, the probability of a new hemorrhages after SRS was reduced for patient older than 35 years (HR = 0.21, p = 0.002) and increased with a margin dose > 13 Gy (HR = 2.57, p = 0.044). Adverse radiation effect (ARE) occurred in 9 patients (5.3%) and was symptomatic in four (2.4%). At a median follow-up of 3.4 years (Inter-quartile range: 5.4), 13 patients (8.0%) had a worsened clinical status, with the treated CCM being the cause in 5.6% (10) of the patients. Single-session SRS decreased the risk of repeat hemorrhage in patients with hemorrhagic brainstem CCM and conveyed this benefit with a low risk of advrse radiation effects (ARE) and worsening clinical status.

Diffusion tensor imaging with tractography in surgical resection of brainstem cavernous malformations: a systematic review and meta-analysis

Brainstem cavernous malformations are benign subset of cerebral cavernous malformations, which need a special intervention owing to being vital and complex. The diffusion tensor imaging technique, a well-recognized neuroimaging tool, can visualize the white matter tracts and their surroundings and provide promising surgical outcomes. This systematic review and meta-analysis evaluated the effect of preoperative diffusion tensor imaging in patients undergoing surgical resection of brainstem cavernous malformations. Five databases, including PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar, were searched using a comprehensive search strategy to find any article matching our inclusion criteria. We used Comprehensive Meta-Analysis (CMA) software to analyze the collected data, get the evidence, and report the results as event rate (ER), with their 95% confidence interval (CI). Twenty-eight studies involving 467 patients matched our criteria and 19 studies entered the analysis. Our analysis showed that, in patients undergoing surgical resection of brainstem cavernous malformations assisted by preoperative diffusion tensor imaging, 82.21% achieved total resection. About 12.4% of patients achieved partial resection, 65.65% improved, 8.07% worsened, 25.04% showed no change, 3.59% experienced postoperative re-bleeding, and 0.87% died. The utilization of preoperative diffusion tensor imaging significantly increased the proportion of improved patients and decreased the proportion of worsened patients. However, further controlled research is needed to draw a definite conclusion about the usefulness of its role.

Microsurgical Resection of Brainstem Cavernous Malformations in Older Adults: A Multicenter, 30-Year Experience

BACKGROUND AND OBJECTIVES

Microsurgical resection is the only curative intervention for symptomatic brainstem cavernous malformations (BSCMs), but the management of these lesions in older adults (≥65 years) is not well described. This study sought to address this gap by examining the safety and efficacy of BSCM resection in a cohort of older adults.

METHODS

Records of patients who underwent BSCM resection over a 30-year period were reviewed retrospectively. Baseline characteristics and outcomes were compared between older (≥65 years) and younger (<65 years) patients.

RESULTS

Of 550 patients with BSCM who met inclusion criteria, 41 (7.5%) were older than 65 years. Midbrain (43.9% vs 26.1%) and medullary lesions (19.5% vs 13.6%) were more common in the older cohort than in the younger cohort ( P = .01). Components of the Lawton BSCM grading system (ie, lesion size, crossing axial midpoint, developmental venous anomaly, and timing of hemorrhage) were not significantly different between cohorts ( P ≥ .11). Mean (SD) Elixhauser comorbidity score was significantly higher in older patients (1.86 [1.06]) than in younger patients (0.66 [0.95]; P < .001). Older patients were significantly more likely than younger patients to have poor outcomes at final follow-up (28.9% vs 13.8%, P = .01; mean follow-up duration, 28.7 [39.1] months). However, regarding relative neurological outcome (preoperative modified Rankin Scale to final modified Rankin Scale), rate of worsening was not significantly different between older and younger patients (23.7% vs 14.9%, P = .15).

CONCLUSION

BSCMs can be safely resected in older patients, and when each patient's unique health status and life expectancy are taken into account, these patients can have outcomes similar to younger patients.

Giant Intracranial Cavernous Malformations: A Review on Magnetic Resonance Imaging Characteristics

Background  Intracranial cavernous malformations (CMs), commonly known as cavernomas or cavernous angiomas, are low-flow, well-circumscribed vascular lesions composed of sinusoidal spaces lined by a single layer of endothelium and separated by a collagenous matrix without elastin, smooth muscle, or other vascular wall elements. A diameter greater than 3 cm for a CM is unlikely. These lesions may have atypical appearances on magnetic resonance imaging (MRI). MRI with advanced techniques such as a susceptibility-weighted image or T2-gradient echo, a diffusion-weighted image and corresponding apparent diffusion coefficient map, and diffusion tensor tractography have revolutionized the diagnostic approach to these lesions. Materials and Method  The present study reviews the etiopathogenesis, clinical manifestations, MRI strategy, and MRI appearances of the CMs, with a few examples of the giant CMs from our archive. Results  Intracranial giant CMs may have unexpected locations, sizes, numbers, and varied imaging appearances due to repeated hemorrhages, unusual enhancement patterns, intense perifocal edema, and unusual associations, making the differential diagnosis difficult. Conclusion  Familiarity with the MRI appearances of the giant intracranial CMs and the differential diagnosis improves diagnostic accuracy and patient management.

Superior frontal sulcus: a non-eloquent corridor for cavernomas of the internal capsule

Introduction

Deep cavernomas of eloquent areas, located in the region of the basal nuclei and thalamus, account for 9 to 36% of these encephalic vascular malformations. Internal capsule cavernomas are particularly challenging, as they are surrounded by important projection fibers and their manipulation can lead to permanent deficits. To demonstrate through surgical cases that cavernomas of the internal capsule can be approached by frontal craniotomy, via the superior frontal sulcus, in a curative manner and with low morbidity.

Methods

We presented two cases of cavernomas of the internal capsule operated, whose treatment was microsurgical resection via frontal craniotomy and access to the lesion via the superior frontal sulcus, described step-by-step. To elucidate the rationale behind the decision, we used preoperative images with an emphasis on the patients' tractography and the importance of comparing these images with anatomical specimens dissected in the neuroanatomy and microsurgery laboratory.

Results

The two cases of internal capsule cavernomas, one in the anterior limb and the other in the posterior limb, were treated surgically via the superior frontal sulcus.

Discussion

Both patients showed radiological cure and clinical improvement in the post-operative segment. The patient consented to the procedure and to the publication of his/her image. Treatment of internal capsule cavernomas via the superior frontal sulcus has proven to be a safe and effective option.

Clinical Features and Treatment of Pediatric Cerebral Cavernous Malformations

Cerebral cavernous malformation (CCM) is a vascular anomaly commonly found in children and young adults. Common clinical presentations of pediatric patients with CCMs include headache, focal neurological deficits, and seizures. Approximately 40% of pediatric patients are asymptomatic. Understanding the natural history of CCM is crucial and hemorrhagic rates are higher in patients with an initial hemorrhagic presentation, whereas it is low in asymptomatic patients. There is a phenomenon known as temporal clustering in which a higher frequency of symptomatic hemorrhages occurs within a few years following the initial hemorrhagic event. Surgical resection remains the mainstay of treatment for pediatric CCMs. Excision of a hemosiderin-laden rim is controversial regarding its impact on epilepsy outcomes. Stereotactic radiosurgery is an alternative treatment, especially for deepseated CCMs, but its true efficacy needs to be verified in a clinical trial.

Management of sporadic intracranial vascular malformations in pregnancy: a retrospective analysis

BACKGROUND

Sporadic intracranial vascular malformations can pose significant risk to parturients, and additional reports of management may inform patient care. Here we describe the peripartum management of parturients with intracranial vascular malformations.

METHODS

After Institutional Review Board approval, we performed a retrospective analysis of parturients with a known sporadic intracranial vascular malformation including cavernous malformation, developmental venous anomaly, or arteriovenous malformation who delivered at our institution between 2007 and 2020.

RESULTS

We identified 10 parturients (five cavernous malformations, three developmental venous anomalies, and two arteriovenous malformations) with 16 deliveries. Among all deliveries, 13 (81.3%) were cesarean deliveries without trial of labor; 11 of these (84.6%) received a single-shot spinal and two (15.4%) received an epidural for surgical anesthesia. Two deliveries (12.5%) began with attempted trial of labor but ultimately required cesarean delivery for failure to progress; one of these cases received epidural anesthesia and the other received combined spinal-epidural anesthesia. One delivery was via spontaneous vaginal delivery with epidural analgesia. Overall, our study's cesarean delivery rate was 93.8% and spontaneous vaginal delivery rate was 6.2%. Three of 16 pregnancies were complicated by seizure, obstructive hydrocephalus, or intracranial hemorrhage. There were no intensive care unit admissions or maternal deaths.

CONCLUSIONS

In our case series of 16 deliveries, there were no complications directly resulting from neuraxial procedures. It remains unclear whether intracranial developmental venous anomalies or unruptured arteriovenous malformations impart increased risk during pregnancy. Antepartum planning with a multidisciplinary team approach enables risk stratification and optimal management.

Fully endoscopic approach for resection of brainstem cavernous malformations: a systematic review of the literature

BACKGROUND

Brainstem cavernous malformations (BCMs) are benign lesions that typically have an acute onset and are associated with a high rate of morbidity. The selection of the optimal surgical approach is crucial for obtaining favorable outcomes, considering the different anatomical locations of various brainstem lesions. Endoscopic surgery is increasingly utilized in treating of BCMs, owing to its depth illumination and panoramic view capabilities. For intra-axial ventral BCMs, the best surgical options are endoscopic endonasal approaches, following the "two-point method. For cavernous hemangiomas on the dorsal side of the brainstem, endoscopy proves valuable by providing enhanced visualization of the operative field and minimizing the need for brain retraction.

METHODS

In this review, we gathered data on the fully endoscopic approach for the resection of BCMs, and outlined technical notes and tips. Total of 15 articles were included in this review. The endoscopic endonasal approach was utilized in 19 patients, and the endoscopic transcranial approach was performed in 3 patients.

RESULTS

The overall resection rate was 81.8% (18/22). Among the 19 cases of endoscopic endonasal surgery, postoperative cerebrospinal fluid (CSF) leakage occurred in 5 cases, with lesions exceeding 2 cm in diameter in 3 patients with postoperative CSF rhinorrhea. Among the 20 patients with follow-up data, 2 showed no significant improvement after surgery, whereas the remaining 18 patients showed significant improvement compared to their admission symptoms.

CONCLUSIONS

This systematic literature review demonstrates that a fully endoscopic approach is a safe and effective option for the resection of BCMs. Further, it can be considered an alternative to conventional craniotomy, particularly when managed by a neurosurgical team with extensive experience in endoscopic surgery, addressing these challenging lesions.

Optochiasmatic Cavernomas: Updated systematic review and proposal of a novel classification with surgical approaches

Cavernomas are histologically benign vascular malformations found at different sites in the brain. A rare site for such cavernomas, however, is the anterior optic pathway, comprising the optic nerve, chiasma, and optic tract-called optochiasmatic cavernomas (OCC). These lesions usually present with sudden onset or progressive vision loss, headache, and features mimicking pituitary apoplexy. In this paper, we describe a case of OCC operated at our center. We carry out an updated review of literature depicting cases of OCC, their clinical presentation, management, and postoperative complications. We also propose a novel classification system based on lesion location and further analyze these cavernoma types with respect to the surgical approach used and visual outcome. A 30-year-old lady had presented with a 3-week history of progressive bilateral vision loss and headache. Based on imaging, she was suspected to have a cavernous angioma of the chiasma and left optic tract. Due to progressive vision deterioration, the lesion was surgically excised using pterional craniotomy. Postoperatively, her visual symptoms improved, but she developed diabetes insipidus. Clinical and radiological follow-up has been done for 18 months after surgery. A total of 81 cases have been described in the literature, including the present case. Chiasmal apoplexy is the most common presentation. Surgical excision is the standard of care. Our analysis based on lesion location shows the most appropriate surgical approach to be used for each cavernoma type. Visual outcome correlates with the preoperative visual status. Visual outcome is good in patients presenting with acute chiasmal apoplexy, and when complete surgical excision is performed. The endonasal endoscopic approach was found to provide the best visual outcome. In addition to preoperative visual status, complete surgical excision predicts favorable visual outcomes in OCC. Our proposed classification system guides the appropriate surgical approach required for a particular location of the cavernoma.

The rare case of optic nerve cavernoma: A case report depicting the diagnostic challenge

The manuscript describes a case of Cavernous Malformation in the optic pathway which is extremely rare, accounting for less than 1% of central nervous system cavernomas. This case report highlights a patient initially diagnosed with a glioma, but subsequent MRI changes and extensive analysis ruled in favor of a hemorrhagic optic neuropathy caused by an optic nerve cavernoma. The patient experienced temporary vision loss but fully regained her vision within a week. Based on clinical, biochemical, and radiological findings, it was confirmed as a rare case of optic nerve cavernoma, and the patient was managed expectantly due to her complete recovery of vision. Follow-up imaging after 1 year indicated a stable lesion with evolving characteristics consistent with a cavernoma. This study provides an informative review of the condition and highlights the key radiologic features of this disease.

Case report: Thrombolysis in patients with acute ischemic stroke and cerebral cavernous malformation

Background

Cerebral cavernous malformation (CCM) is a rare disease associated with a latent risk of intracranial hemorrhage. However, due to limited evidence, the safety of recommending intravenous tissue plasminogen activators for patients with acute stroke and CCM remains uncertain.

Methods

Our study identified five patients with acute stroke and CCM treated between 2017 and 2023 across two hospitals. A comprehensive literature review was conducted, incorporating three similar case reports and two retrospective studies.

Results

Among 30 patients reviewed, three exhibited symptomatic intracranial hemorrhage, two of whom were women. Additionally, three patients presented with calcification in their CCM, with two experiencing symptomatic intracranial hemorrhage.

Conclusion

The observed incidence of symptomatic intracranial hemorrhage following intravenous tissue plasminogen activator administration appears to be elevated in patients with CCM. Therefore, before thrombolysis, a thorough evaluation of personalized risk-benefit ratios is crucial. Furthermore, conducting further research involving multiple centers and larger sample sizes is imperative to advance our understanding in this area, especially in identifying hemorrhage risk factors.

Peritrigeminal Safe Entry Zone Access to Anterolateral Pons Using the Presigmoid Retrolabyrinthine Suprameatal Approach: A Cadaveric Morphometric Study

BACKGROUND AND OBJECTIVES

Access to the anterolateral pontine lesions can be achieved through the peritrigeminal and supratrigeminal safe entry zones using Kawase, retrosigmoid, or translabyrinthine approaches. However, these approaches entail shallow extensive dissection, tangential access, and compromise vestibulocochlear function. We aimed to investigate infratentorial presigmoid retrolabyrinthine approach to access pontine lesions through the peritrigeminal zone.

METHODS

We performed 10 presigmoid retrolabyrinthine suprameatal approach dissections in 5 cadaveric heads. Anatomic-radiological characteristics and variations were evaluated. Six morphometric parameters were measured and analyzed to predict surgical accessibility.

RESULTS

The pontine infratrigeminal area was accessible in all patients. The mean exposed area of the anterolateral pontine surface was 98.95 cm 2 (±38.11 cm 2 ). The mean length of the exposed trigeminal nerve was 7.9 cm (±2.9 cm). Preoperative anatomic-radiological parameters may allow to select patients with favorable anatomy that offers appropriate surgical accessibility to the anterior pontine cavernoma through a presigmoid retrolabyrinthine corridor.

CONCLUSION

Anterolateral pontine lesions can be accessed through a minimally invasive infratentorial presigmoid retrolabyrinthine approach by targeting the infratrigeminal safe entry zone. Further clinical studies should be conducted to evaluate the viability of this technique for treating these complex pathologies in real clinical settings.

Readmissions in patients with cerebral cavernous malformations: a national readmission database study

BACKGROUND

Cerebral cavernous malformations (CCMs) are microvascular CNS lesions prone to hemorrhage leading to neurological sequela such as stroke and seizure. A subset of CCM patients have aggressive disease leading to multiple bleeding events, likely resulting multiple hospitalizations. Hospital admission rates are an important metric that has direct financial impact on hospitals and an indicator of overall disease burden. Furthermore, analysis of hospital readmissions can lead to early identification of high-risk patients and provides insight into the pathogenesis of CCM lesions. The purpose of this study is to identify high risk CCM patients with increased all cause readmission and comorbidities associated with increased readmissions.

METHODS

All US hospital admissions due to CCMs were searched using the 2017 National Readmission Database (NRD). Patients with readmissions within 30 days of discharge from index hospitalization were identified and analyzed, relative to the remaining population.

RESULTS

Among all patients hospitalized for CCM, 14.9% (13.7-16.2%) required all cause readmission within 30 days. Multivariate logistical regression analysis showed that substance abuse (P=0.003), diabetes (P=0.018), gastrointestinal bleed (P=0.002), renal failure (P=0.027), and coronary artery disease (P=0.010) were predictive of all cause readmissions, while age group 65-74 (P=0.042), private insurance (P<0.001), and treatment at a metropolitan teaching institution (P=0.039) were protective. Approximately half of all readmissions are caused by neurological (33.9%) and infectious (14.6%) etiologies. The 30-day lesion bleeding rate after index hospitalization is 0.8% (0.5-1.2%).

CONCLUSIONS

All identified comorbidities associated with increased risks of readmission contribute to vascular stress, suggesting its role in lesion pathogenesis. This is the first and only study to analyze readmission metrics for CCMs in order to identify high risk patient factors to date.

Long-term functional outcomes and complications of microsurgical resection of brainstem cavernous malformations: a systematic review and meta-analysis

Brainstem cavernous malformations (CMs) encompass up to 20% of all intracranial CMs and are considered more aggressive than cerebral CMs because of their high annual bleeding rates. Microsurgical resection remains the primary treatment modality for CMs, but long-term functional outcomes and complications are heterogenous in the literature. The authors performed a systematic review on brainstem CMs in 4 databases: PubMed, EMBASE, Cochrane library, and Google Scholar. We included studies that reported on the long-term functional outcomes and complications of brainstem CMs microsurgical resection. A meta-analysis was performed and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The search yielded 4781 results, of which 19 studies met our inclusion criteria. Microsurgery was performed on 940 patients (mean age 35 years, 46.9% females). Most of the brainstem CMs were located in the pons (n = 475). The pooled proportions of improved, stable, and worsened functional outcomes after microsurgical resection of brainstem CMs were 56.7% (95% CI 48.4-64.6), 28.6% (95% CI 22.4-35.7), and 12.6% (95% CI 9.6-16.2), respectively. CMs located in the medulla were significantly (p = 0.003) associated with a higher proportion of improved outcome compared with those in the pons and midbrain. Complete resection was achieved in 93.3% (95% CI 89.8-95.7). The immediate postoperative complication rate was 37.2% (95% CI 29.3-45.9), with new-onset cranial nerve deficit being the most common complication. The permanent morbidity rate was 17.3% (95% CI 10.5-27.1), with a low mortality rate of 1% from the compiled study population during a mean follow-up of 58 months. Our analysis indicates that microsurgical resection of brainstem CMs can result in favorable long-term functional outcomes with transient complications in the majority of patients. Complete microsurgical resection of the CM is associated with a lower incidence of CM hemorrhage and the morbidity related to it.

The Brainstem Cavernoma Case Series: A Formula for Surgery and Surgical Technique

Background and Objectives: Cavernous malformations (CM) are vascular malformations with low blood flow. The removal of brainstem CMs (BS) is associated with high surgical morbidity, and there is no general consensus on when to treat deep-seated BS CMs. The aim of this study is to compare the surgical outcomes of a series of deep-seated BS CMs with the surgical outcomes of a series of superficially located BS CMs operated on at the Department of Neurosurgery, College of Tuebingen, Germany. Materials and Methods: A retrospective evaluation was performed using patient charts, surgical video recordings, and outpatient examinations. Factors were identified in which surgical intervention was performed in cases of BS CMs. Preoperative radiological examinations included MRI and diffusion tensor imaging (DTI). For deep-seated BS CMs, a voxel-based 3D neuronavigation system and electrophysiological mapping of the brainstem surface were used. Results: A total of 34 consecutive patients with primary superficial (n = 20/58.8%) and deep-seated (n = 14/41.2%) brainstem cavernomas (BS CM) were enrolled in this comparative study. Complete removal was achieved in 31 patients (91.2%). Deep-seated BS CMs: The mean diameter was 14.7 mm (range: 8.3 to 27.7 mm). All but one of these lesions were completely removed. The median follow-up time was 5.8 years. Two patients (5.9%) developed new neurologic deficits after surgery. Superficial BS CMs: The median diameter was 14.9 mm (range: 7.2 to 27.3 mm). All but two of the superficial BS CMs could be completely removed. New permanent neurologic deficits were observed in two patients (5.9%) after surgery. The median follow-up time in this group was 3.6 years. Conclusions: The treatment of BS CMs remains complex. However, the results of this study demonstrate that with less invasive posterior fossa approaches, brainstem mapping, and neuronavigation combined with the use of a blunt "spinal cord" dissection technique, deep-seated BS CMs can be completely removed in selected cases, with good functional outcomes comparable to those of superficial BS CM.

The Infratrigeminal Suprafloccular Approach to Intrapontine Lesions: An Anatomical Overview and Relevance for the Approach to Intrapontine Lesions

Background and objectives Brainstem lesions have long been considered complex pathologies that may lead to permanent deficits or life-threatening complications, posing significant challenges for surgical removal. Among these lesions, intrapontine lesions are particularly challenging in the field of neurosurgery. However, with advancements in microsurgical anatomy knowledge and technology, these lesions have become more amenable to surgical treatment. In this study, the authors examine an infratrigeminal suprafloccular approach, which has been shown to be a safe surgical route, resulting in fewer postoperative complications, while evaluating the anatomical nuances of the approach and route. Methods Twenty cadaveric brainstem specimens were analyzed to assess the anatomy, focusing on the lateral aspect of the pons as a potential safe entry zone for intrapontine lesions. The authors consistently analyzed twenty brainstem specimens, carefully examining the pontine microsurgical anatomy. A triangular area of entrance was measured, with three sides or walls (X, Y, and Z) aiming to identify the safe zone that would spare the distinct pontine nuclei, ascending sensory pathways, corticospinal, corticonuclear, and corticopontine tracts of the brainstem. An illustrative case was adapted to the described safe entry zone for corroboration purposes. Results The authors measured three distinct lines on the lateral surface of the pons, named X, Y, and Z, forming a triangle in shape. Line X extended from the midpoint anteroposteriorly of the flocculus of the cerebellum to the apparent trigeminal exit in the lateral aspect of the pons. Line Y ran from the trigeminal exit in the pons to the apparent exit of the facial-vestibulocochlear complex in the far lateral aspect of the pontomedullary sulcus in the cerebellopontine fissure. Line Z represented the measurement from the vestibulocochlear complex to the midpoint anteroposteriorly of the flocculus of the cerebellum. The mean measurements were as follows: X = 14.41mm (range: 10mm to 20mm), Y = 13.1mm (range: 10mm to 21mm), and Z = 3mm (range: 2mm to 5mm). The mean surface area of the analyzed specimens within the triangle (formed by X, Y, and Z) was 20.1mm² (range: 10mm² to 40mm²). This area was identified as a safe zone for the entry of microsurgical approaches to intrapontine lesions, involving less retraction of the anterior pons and potentially sparing critical structures, such as the corticospinal tracts, pontine perforating arteries, tegmentum pontis, cranial nerve nuclei, substantia reticulata dorsally, and transverse pontine fibers. Microsurgical anatomical findings, combined with intraoperative monitoring in an illustrative case, consistently demonstrated that this entry area predicted less functional instability of the analyzed tracts and resulted in fewer postoperative complications. Conclusion Deep-seated pontine lesions present a complex range of pathologies with a high potential for devastating outcomes, particularly those involving hemorrhage. This study identifies and describes a presumed safe entry zone that allows for the creation of a surgical corridor for biopsy or microsurgical resection of these lesions, reducing morbidity in a previously considered impenetrable region.

Cavernous hemangioma of the cisternal segment of the auditory nerve: case report

BACKGROUND

Extraaxial cerebellopontine angle cavernous hemangiomas are rare and their diagnosis and treatment are challenging.

CASE PRESENTATION

A 43-year-old female was admitted to the hospital who had repeated hearing loss in her left ear accompanied by tinnitus. Magnetic resonance imaging revealed a hemangioma-like lesion in the left cerebellopontine angle extra-axial cisternal segment. During the surgery, it was found that the lesion was located in the cisternal segment of the root of the auditory nerve. Postoperative pathological examination confirmed that the lesion was a cavernous hemangioma.

CONCLUSION

We report a case of cavernous hemangioma in the brain spatula cisternal segment of the left auditory nerve. For cranial nerve CMs early diagnosis and surgical removal may maximize the chance of a positive outcome.

Case report: Delayed outflow obstruction of a DVA: A rare complication of brainstem cavernoma surgery

Introduction

Developmental venous anomalies (DVAs) are considered variants of normal transmedullary veins. Their association with cavernous malformations is reported to increase the risk of hemorrhage. Expert consensus recommends meticulous planning with MR imaging, use of anatomical “safe zones”, intraoperative monitoring of long tracts and cranial nerve nuclei, and preservation of the DVA as key to avoiding complications in brainstem cavernoma microsurgery. Symptomatic outflow restriction of DVA is rare, with the few reported cases in the literature restricted to DVAs in the supratentorial compartment.

Case

We present a case report of the resection of a pontine cavernoma complicated by delayed outflow obstruction of the associated DVA. A female patient in her 20's presented with progressive left-sided hemisensory disturbance and mild hemiparesis. MRI revealed two pontine cavernomas associated with interconnected DVA and hematoma. The symptomatic cavernoma was resected via the infrafacial corridor. Despite the preservation of the DVA, the patient developed delayed deterioration secondary to venous hemorrhagic infarction. We discuss the imaging and surgical anatomy pertinent to brainstem cavernoma surgery, as well as the literature exploring the management of symptomatic infratentorial DVA occlusion.

Conclusion

Delayed symptomatic pontine venous congestive edema is extremely rare following cavernoma surgery. DVA outflow restriction from a post-operative cavity, intraoperative manipulation, and intrinsic hypercoagulability from COVID-10 infection are potential pathophysiological factors. Improved knowledge of DVAs, brainstem venous anatomy, and “safe entry zones” will further elucidate the etiology of and the efficacious treatment for this complication.

Safety of brainstem safe entry zones: comparison of microsurgical outcomes associated with superficial, exophytic, and deep brainstem cavernous malformations

OBJECTIVE

Safe entry zones (SEZs) enable safe tissue transgression to lesions beneath the brainstem surface. However, evidence for the safety of SEZs is scarce and is based on anatomical studies, case reports, and small series.

METHODS

A cohort of 154 patients who underwent microsurgical brainstem cavernous malformation (BSCM) treatment during a 23-year period and who had preoperative MR images and intraoperative photographs or videos was retrospectively examined. This study assessed the safety of SEZs for access to deep BSCMs, preoperative MRI to predict BSCM surface proximity, and the relationships between BSCM subtype, surgical approach, and SEZs. Lesions were characterized as exophytic, superficial, or deep on the basis of preoperative MRI and intraoperative inspection. Outcomes were scored as good (modified Rankin Scale [mRS] score ≤ 2) or poor (mRS score > 2) and relative outcomes as stable/improved or worse relative to baseline (± 1 point).

RESULTS

Resections included 34 (22%) in the midbrain, 102 (66%) in the pons, and 18 (12%) in the medulla. Of those, 23 (15%) were exophytic, 57 (37%) were superficial, and 74 (48%) were deep. Established SEZs were used for 97% (n = 72) of deep lesions; the preferred SEZ associated with its subtype was used for 91% (n = 67). MR images accurately depicted exophytic BSCMs that did not require SEZ approaches (sensitivity, 96%) but overestimated the proximity of lesions superficial to brainstem surfaces (specificity, 67%), resulting in unanticipated SEZ use. Final neurological outcomes were good in 80% of patients with follow-up data (119/149), and relative outcomes were stable/improved in 93% (139/149). Outcomes for patients with brainstem transgression through an SEZ did not differ from outcomes for patients with superficial or exophytic lesions that did not require SEZ use (final mRS score ≤ 2 in 72% of all patients with deep lesions vs 82% of all patients with superficial or exophytic lesions [p = 0.10]). Among patients with follow-up, the rates of permanent new cranial nerve deficits in patients with deep BSCMs and superficial or exophytic BSCMs were 21% and 20%, respectively (p = 0.81), with no significant change in overall cranial nerve deficit (0 and -1, p = 0.65).

CONCLUSIONS

Neurological outcomes for patients with deep BSCMs were equivalent to those for superficial or exophytic BSCMs, validating the safety of SEZs for deep BSCMs. Preoperative T1-weighted MR images overestimated the lesion's surface proximity, necessitating detailed knowledge of SEZs and readiness to use them in cases of radiological-microsurgical discordance. Most patients achieved favorable outcomes despite the transgression of eloquent brainstem tissue in and around SEZs.

mPR-Specific Actions Influence Maintenance of the Blood–Brain Barrier (BBB)

Cerebral cavernous malformations (CCMs) are characterized by abnormally dilated intracranial microvascular sinusoids that result in increased susceptibility to hemorrhagic stroke. It has been demonstrated that three CCM proteins (CCM1, CCM2, and CCM3) form the CCM signaling complex (CSC) to mediate angiogenic signaling. Disruption of the CSC will result in hemorrhagic CCMs, a consequence of compromised blood–brain barrier (BBB) integrity. Due to their characteristically incomplete penetrance, the majority of CCM mutation carriers (presumed CCM patients) are largely asymptomatic, but when symptoms occur, the disease has typically reached a clinical stage of focal hemorrhage with irreversible brain damage. We recently reported that the CSC couples both classic (nuclear; nPRs) and nonclassic (membrane; mPRs) progesterone (PRG)-receptors-mediated signaling within the CSC-mPRs-PRG (CmP) signaling network in nPR(−) breast cancer cells. In this report, we demonstrate that depletion of any of the three CCM genes or treatment with mPR-specific PRG actions (PRG/mifepristone) results in the disruption of the CmP signaling network, leading to increased permeability in the nPR(−) endothelial cells (ECs) monolayer in vitro. Finally, utilizing our in vivo hemizygous Ccm mutant mice models, we demonstrate that depletion of any of the three CCM genes, in combination with mPR-specific PRG actions, is also capable of leading to defective homeostasis of PRG in vivo and subsequent BBB disruption, allowing us to identify a specific panel of etiological blood biomarkers associated with BBB disruption. To our knowledge, this is the first report detailing the etiology to predict the occurrence of a disrupted BBB, an indication of early hemorrhagic events.

Neurological event prediction for patients with symptomatic cerebral cavernous malformation: the BLED2 score

OBJECTIVE

Retrospective patient cohort studies have identified risk factors associated with recurrent focal neurological events in patients with symptomatic cerebral cavernous malformations (CCMs). Using a prospectively maintained database of patients with CCMs, this study identified key risk factors for recurrent neurological events in patients with symptomatic CCM. A simple scoring system and risk stratification calculator was then created to predict future neurological events in patients with symptomatic CCMs.

METHODS

This was a dual-center, prospectively acquired, retrospectively analyzed cohort study. Adult patients who presented with symptomatic CCMs causing focal neurological deficits or seizures were uniformly treated and clinically followed from the time of diagnosis onward. Baseline variables included age, sex, history of intracerebral hemorrhage, lesion multiplicity, location, eloquence, size, number of past neurological events, and duration since last event. Stepwise multivariable Cox regression was used to derive independent predictors of recurrent neurological events, and predictive accuracy was assessed. A scoring system based on the relative magnitude of each risk factor was devised, and Kaplan-Meier curve analysis was used to compare event-free survival among patients with different score values. Subsequently, 1-, 2-, and 5-year neurological event rates were calculated for every score value on the basis of the final model.

RESULTS

In total, 126 (47%) of 270 patients met the inclusion criteria. During the mean (interquartile range) follow-up of 54.4 (12-66) months, 55 patients (44%) experienced recurrent neurological events. Multivariable analysis yielded 4 risk factors: bleeding at presentation (HR 1.92, p = 0.048), large size ≥ 12 mm (HR 2.06, p = 0.016), eloquent location (HR 3.01, p = 0.013), and duration ≤ 1 year since last event (HR 9.28, p = 0.002). The model achieved an optimism-corrected c-statistic of 0.7209. All factors were assigned 1 point, except duration from last event which was assigned 2 points. The acronym BLED2 summarizes the scoring system. The 1-, 2-, and 5-year risks of a recurrent neurological event ranged from 0.6%, 1.2%, and 2.3%, respectively, for patients with a BLED2 score of 0, to 48%, 74%, and 93%, respectively, for patients with a BLED2 score of 5.

CONCLUSIONS

The BLED2 risk score predicts prospective neurological events in symptomatic CCM patients.

Pediatric brainstem cavernous malformations: 2-center experience in 40 children

OBJECTIVE

Brainstem cavernous malformations (BSCMs) are relatively uncommon, low-flow vascular lesions in children. Given the paucity of data, guidelines regarding the clinical management of BSCMs in children are lacking and the surgical indication is most commonly based on an individual surgeon's judgment and experience. The goal in this study was to evaluate the clinical behavior of BSCMs in childhood and the long-term outcome in children managed conservatively and surgically.

METHODS

This was an observational, retrospective study including all children with BSCMs who were followed at 2 institutions between 2008 and 2020.

RESULTS

The study population consisted of 40 children (27 boys, 67.5%) with a mean age of 11.4 years. Twenty-three children (57.5%) were managed conservatively, whereas 17 children (42.5%) underwent resection of BSCMs. An aggressive clinical course was observed in 13 children (32.5%), who experienced multiple hemorrhages with a progressive pattern of neurological decline. Multiple BSCMs were observed in 8 patients, of whom 3 patients presented with a complex of multiple tightly attached BSCMs and posed a significant therapeutic challenge. The overall long-term outcome was favorable (modified Rankin Scale [mRS] scores 0-2) in 36 patients (90%), whereas an unfavorable outcome (mRS scores 3 and 4) was seen in 4 children (10%). An mRS score of 5 or 6 was not observed. The mean (± SD) follow-up was 88.0 (± 92.6) months.

CONCLUSIONS

The clinical course of BSCMs in children is highly variable, with benign lesions on the one hand and highly aggressive lesions with repetitive hemorrhages on the other. Given the greater life expectancy and the known higher functional recovery in children, surgical treatment should be considered early in young patients presenting with surgically accessible lesions and an aggressive clinical course, and it should be performed in a high-volume center.

Endoscope-assisted resection of brainstem cavernous malformations

Targeted surgical precision and minimally invasive techniques are of utmost importance for resectioning cavernous malformations involving the brainstem region. Minimisation of the surgical corridor is desirable but should not compromise the extent of resection. This study provides detailed information on the role of endoscopy in this challenging surgical task. A retrospective analysis of medical documentation, radiologic studies and detailed intraoperative video documentation was performed for all consecutive patients who underwent surgical resection of brainstem cavernous malformations between 2010 and 2020 at the authors’ institution. A case-based volumetry of the corticotomy was performed and compared to cavernoma dimensions. A total of 20 procedures have been performed in 19 patients. Neuroendoscopy was implemented in all cases. The mean size of the lesion was 5.4 (± 5) mm3. The average size of the brainstem corticotomy was 4.5 × 3.7 (± 1.0 × 1.1) mm, with a median relation to the cavernoma’s dimension of 9.99% (1.2–31.39%). Endoscopic 360° inspection of the resection cavity was feasible in all cases. There were no endoscopy-related complications. Mean follow-up was 27.8 (12–89) months. Gross-total resection was achieved in all but one case (95%). Sixteen procedures (80%) resulted in an improved or stable medical condition. Eleven patients (61.1%) showed further improvement 12 months after the initial surgery. With the experience provided, endoscopic techniques can be safely implemented in surgery for BSCM. A combination of neuroendoscopic visualisation and neuronavigation might enable a targeted size of brainstem corticotomy. Endoscopy can currently be considered a valuable additive tool to facilitate the preparation and resection of BSCM.

External validation of the Lawton brainstem cavernous malformation grading system in a cohort of 277 microsurgical patients

OBJECTIVE

The brainstem cavernous malformation (BSCM) grading system predicts neurological outcomes associated with microsurgical resection and assists neurosurgeons in selecting patients for treatment. The predictive accuracy of the BSCM grading system should be validated in a large cohort from high-volume centers to generalize its use.

METHODS

An external validation cohort comprised patients with a BSCM resected by the senior author (M.T.L.) since the publication of the BSCM grading system and those resected by another neurosurgeon (R.F.S.) over a 16-year period. Size, crossing the axial midpoint, the presence of a developmental venous anomaly, patient age, and timing of last hemorrhage were used to assign BSCM grades from 0 to VII. Poor neurological outcomes were recorded as modified Rankin Scale scores > 2 at last follow-up examination.

RESULTS

A total of 277 patients were included in the study. The average BSCM grade was 3.9, and the majority of BSCMs (181 patients, 65%) were intermediate grade (grades III-V). Outcomes were predicted by BSCM grade, with good outcomes observed in 47 of 54 patients (87%) with low-grade BSCMs, in 135 of 181 patients (75%) with intermediate-grade BSCMs, and in 21 of 42 patients (50%) with high-grade BSCMs. Conversely, proportions of patients with neurological deterioration increased with increasing BSCM grade, with worsening observed in 2 of 54 patients (4%) with low-grade BSCMs, in 29 of 181 patients (16%) with intermediate-grade BSCMs, and in 17 of 42 patients (40%) with high-grade BSCMs. In the chi-square analysis, high-grade BSCMs were associated with increased odds of neurological worsening compared to low- and intermediate-grade BSCMs (OR 5.0, 95% CI 2.4-10.4; p < 0.001). The receiver operating characteristic analysis demonstrated acceptable discrimination for predicting unfavorable functional outcomes (modified Rankin Scale score > 2) with an area under the curve of 0.74 (95% CI 0.68-0.80; p < 0.001).

CONCLUSIONS

This study validates the BSCM grading system in a large cohort of patients from two high-volume surgeons. BSCM grade predicted neurological outcomes with accuracy comparable to that of other grading systems in widespread use. The BSCM grading system establishes categories of low-, intermediate-, and high-grade BSCMs and a boundary or cutoff for surgery at BSCM grade V. BSCM grading guides the analysis of a particular patient's condition, but treatment recommendations must be individualized, and neurosurgeons must calibrate BSCM grading to their own outcome results, unique abilities, and practices.

Cerebral cavernous malformations do not fall in the spectrum of PIK3CA-related overgrowth

Somatic gain-of-function (GOF) mutations in phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), the catalytic subunit of phosphoinositide 3-kinase (PI3K), have been recently discovered in cerebral cavernous malformations (CCMs), raising the possibility that the activation of PI3K pathways is a possible universal regulator of vascular morphogenesis. However, there have been contradicting data presented among various groups and studies. To enhance the current understanding of vascular anomalies, it is essential to explore this possible relationship between altered PI3K signalling pathways and its influence on the pathogenesis of CCMs. GOF PIK3CA-mutants have been linked to overgrowth syndromes, allowing this group of disorders, resulting from somatic activating mutations in PIK3CA, to be collectively named as PIK3CA-related overgrowth spectrum disorders. This paper reviews and attempts to conceptualise the relationships and differences among clinical presentations, genotypic and phenotypic correlations and possible coexistence of PIK3CA and CCM mutations/phenotypes in CCM lesions. Finally, we present a model reflecting our hypothetical understanding of CCM pathogenesis based on a systematic review and conceptualisation of data obtained from other studies.

Isolated tectal cavernomas: A comprehensive literature review with a case presentation

Intracranial cavernous angiomas or cavernomas (ICCs) are abnormal blood-filled vasculatures made of mono-endothelial layer and characterized by their bubble-like caverns. Brainstem cavernomas (BSCs) is a critical form of ICCs since slight changes in the lesion can result in devastating or life-threatening outcomes. We hereby present a rare case of BSC developed in the mesencephalic tectum with intraventricular bleeding and Parinaud’s Syndrome. Our patient was managed by complete surgical resection of the lesion through an infra-tentorial supracerebellar approach. Additionally, we reviewed and analyzed the hitherto reported cases of isolated tectal cavernomas (TCs) in the literature, including our case, to elucidate the main factors associated with the management outcomes of TCs. There have been 25 cases of isolated TC reported until now. Most of the patients were adults between 18–77 y of age, except for two children (7 and 13 y). There was no sex predominance. Symptomatic patients presented with headache 56%, altered level of consciousness 24%, and/or double vision 20%. Most cases (64%) had hemorrhagic lesions at presentation, and 60% of all cases experienced recurrent hemorrhages. Parinaud’s Syndrome was recorded in five cases, including the current one. All cases affected with Parinaud’s were males. Lesion size was a determinant of the outcome as larger lesions were more likely to result in persistent deficits. Surgical resection of the lesion was an effective management modality with ∼79% (15/19) of patients who underwent surgery ended up with complete recovery.

•

We reviewed and statistically analyzed all reported cases of isolated tectal cavernoma in PubMed literature.

•

Isolated tectal cavernoma is not associated with specific sex or a certain age.

•

The most common complication associated with this condition is hemorrhage (64%).

•

Parinaud’s Syndrome has been associated with some cases, with its presence being male predominant.

•

Lesion size is significantly associated with outcome as larger lesions (>11 mm) are more likely to induce persistent deficit.

•

Surgical resection is the ultimate management modality as most surgically treated cases ended with complete recovery (79%).

Extradural hemorrhagic spinal cavernous angioma in a paucisymptomatic child: A rare case with review of the current literature

Background:

Cavernous angiomas, also referred to as cavernous hemangiomas or cavernomas (CMs), are vascular malformative benign neoplasms that may develop in any part of the central nervous system. Spinal CMs are uncommon (overall incidence rate of 0.04–0.05%). Pure epidural CMs account for 1–2% of all spinal CMs and 4% of all spinal epidural tumors. Diagnosis is extremely rare in the pediatric age. To the best of our knowledge, only 10 cases have been described so far. The treatment of choice is microsurgical resection.

Case Description:

We describe here the rare case of a cervicothoracic hemorrhagic spinal epidural cavernoma in a paucisymptomatic, 8-year-old female Bangladeshi child. C7–T2 laminectomy with excision of a scarcely defined, capsulated dark red lesion was performed with good recovery.

Conclusion:

Spinal epidural cavernomas are rare. Childhood presentation is even rarer. The reason could be found in a greater “compliance” and to a rarer occurrence of acute bleeding in children, thus resulting in a delayed diagnosis. Surgical excision is the gold standard of treatment.

Clinical application of diffusion tensor imaging and fiber tractography in the management of brainstem cavernous malformations: a systematic review

This study aimed to systematically review the literature to determine the clinical utility and perspectives of diffusion tensor imaging (DTI) in the management of patients with brainstem cavernous malformations (BSCMs). PubMed, Embase, and Cochrane were searched for English-language articles published until May 10, 2021. Clinical studies and case series describing DTI-based evaluation of patients with BSCMs were included. Fourteen articles were included. Preoperative DTI enabled to adjust the surgical approach and choose a brainstem safe entry zone in deep-seated BSCMs. Preoperatively lower fractional anisotropy (FA) of the corticospinal tract (CST) correlated with the severity of CST injury and motor deficits. Postoperatively increased FA and decreased apparent diffusion coefficient (ADC) corresponded with the normalization of the perilesional CST, indicating motor improvement. The positive (PPV) and negative predictive value (NPV) of qualitative DTI ranged from 20 to 75% and from 66.6 to 100%, respectively. The presence of preoperative and postoperative motor deficits was associated with a higher preoperative resting motor threshold (RMT) and lower FA. A higher preoperative CST score was indicative of a lower preoperative and follow-up Medical Research Council (MRC) grade. DTI facilitated the determination of a surgical trajectory with minimized risk of WMTs' damage. Preoperative FA and RMT might indicate the severity of preoperative and postoperative motor deficits. Preoperative CST score can reliably reflect patients' preoperative and follow-up motor status. Due to high NPV, normal CST morphology might predict intact neurological outcomes. Contrarily, sparse and relatively low PPV limits the reliable prediction of neurological deficits.

Brainstem Cavernous Malformations Management: Microsurgery vs. Radiosurgery, a Meta-Analysis

Given the rareness of available data, we performed a systematic review and meta-analysis on therapeutic strategy microsurgical resection and stereotactic radiosurgery (SRS) for brainstem cavernous malformations (BSCMs) and assessed mortality, permanent neurological deficits (PNDs), rebleeding rate, and patients who require reintervention to elucidate the benefits of each treatment modality. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) were used for protocol development and manuscript preparation. After applying all inclusion and exclusion criteria, six remaining articles were included in the final manuscript pool. In total, this meta-analysis included 396 patients, among them 168 patients underwent microsurgical treatment and 228 underwent SRS. Findings of the present meta-analysis suggest that regarding the total group of patients, in terms of mortality, late rebleeding rate, and PNDs, there was no superiority of the one method over the other. Applying the leave-one-out method to our study suggests that with low robust of the results for the bleeding rate and patients who require reintervention outcome factor, there was no statistical difference among the surgical and SRS treatment. Microsurgical treatment of BSCMs immediately eliminates the risk of rehemorrhage; however, it requires complete excision of the lesion and it is associated with a similar rate of PNDs compared with SRS management. Apparently, SRS of BSCMs causes a marked reduction in the risk of rebleeding 2 years after treatment, but when compared with the surgical treatment, there was not any remarkable difference.

Functional Outcomes of Microsurgical Resection for Cavernous Malformations of the Brainstem

Long-term functional outcomes of microsurgical resection for cavernous malformations of the brainstem (CMB) have been largely unknown. Favorable outcomes after CMB surgery might be related to the achievement of complete resection and mRS at 1 month after the surgery. Preoperative sensory, cerebellar, trigeminal nerve, and lower cranial nerve symptoms tended to improve after surgery.We evaluated 25 consecutive patients with CMB surgically treated at our center between 2006 and 2021. The subjects included 11 men and 14 women, with ages ranging from 13 to 61 years (mean ± SD = 37 ± 12 years). Modified Rankin Scale (mRS) scores and neurological symptoms of the patients were evaluated before surgery, 1 month after surgery, and at the final follow-up at the outpatient clinic. The mean number of previous hemorrhages was 7 ± 1.0 and the mean lesion size was 21 ± 8 mm. The mRS scores on admission and at the final follow-up were 2.9 points and 1.7 points, respectively. The mRS scores at the final follow-up were significantly improved compared to those on admission. There was no statistical difference between the preoperative mRS and mRS at 1 month after the operation. Multivariable analysis indicated that mRS scores at 1 month after surgery were the most significant predictive factors for favorable outcomes. Complete resection was achieved in 24 of 33 operations. Incomplete resection was significantly related to the frequency of subsequent recurrent hemorrhage and high mRS scores at the final follow-up. Preoperative sensory, cerebellar, trigeminal nerve, and lower cranial nerve symptoms improved significantly after surgery.

A taxonomy for brainstem cavernous malformations: subtypes of midbrain lesions

OBJECTIVE

Anatomical taxonomy is a practical tool that has successfully guided clinical decision-making for patients with brain arteriovenous malformations. Brainstem cavernous malformations (BSCMs) are similarly complex lesions that are difficult to access and highly variable in size, shape, and position. The authors propose a novel taxonomy for midbrain cavernous malformations based on clinical presentation (syndromes) and anatomical location (identified with MRI).

METHODS

The taxonomy system was developed and applied to an extensive 2-surgeon experience over a 30-year period (1990-2019). Of 551 patients with appropriate data who underwent microsurgical resection of BSCMs, 151 (27.4%) had midbrain lesions. These lesions were further subtyped on the basis of predominant surface presentation identified on preoperative MRI. Five distinct subtypes of midbrain BSCMs were defined: interpeduncular (7 lesions [4.6%]), peduncular (37 [24.5%]), tegmental (73 [48.3%]), quadrigeminal (27 [17.9%]), and periaqueductal (7 [4.6%]). Neurological outcomes were assessed using modified Rankin Scale (mRS) scores. A postoperative score ≤ 2 was defined as a favorable outcome; a score > 2 was defined as a poor outcome. Clinical and surgical characteristics and neurological outcomes were compared among subtypes.

RESULTS

Each midbrain BSCM subtype was associated with a recognizable constellation of neurological symptoms. Patients with interpeduncular lesions commonly presented with ipsilateral oculomotor nerve palsy and contralateral cerebellar ataxia or dyscoordination. Peduncular lesions were associated with contralateral hemiparesis and ipsilateral oculomotor nerve palsy. Patients with tegmental lesions were the most likely to present with contralateral sensory deficits, whereas those with quadrigeminal lesions commonly presented with the features of Parinaud syndrome. Periaqueductal lesions were the most likely to cause obstructive hydrocephalus. A single surgical approach was preferred (> 90% of cases) for each midbrain subtype: interpeduncular (transsylvian-interpeduncular approach [7/7 lesions]), peduncular (transsylvian-transpeduncular [24/37]), tegmental (lateral supracerebellar-infratentorial [73/73]), quadrigeminal (midline or paramedian supracerebellar-infratentorial [27/27]), and periaqueductal (transcallosal-transchoroidal fissure [6/7]). Favorable outcomes (mRS score ≤ 2) were observed in most patients (110/136 [80.9%]) with follow-up data. No significant differences in outcomes were observed between subtypes (p = 0.92).

CONCLUSIONS

The study confirmed the authors' hypothesis that taxonomy for midbrain BSCMs can meaningfully guide the selection of surgical approach and resection strategy. The proposed taxonomy can increase diagnostic acumen at the patient bedside, help identify optimal surgical approaches, enhance the consistency of clinical communications and publications, and improve patient outcomes.

An isolated cavernous malformation of the sixth cranial nerve: A case report and review of literature

Background

Isolated cavernous malformation (CM) of the abducens nerve has not been reported in the literature. Herein, the authors address the clinical importance of these lesions and review the reported cases of CM from 2014 to 2020.

Case Description

A 21-year-old man presented with binocular diplopia and headache from 2 months before his admission. The neurological examination revealed right-sided abducens nerve palsy. The brain MRI revealed an extra-axial pontomedullary lesion suggestive of a CM. The lesion was surgically removed. During the operation, the abducens nerve was resected considering the lesion could not be separated from the nerve and an anastomosis was performed using an interposition nerve graft and fibrin glue. Pathological examination of the resected lesion revealed that it was originated from within the nerve. The patient's condition improved in postoperative follow-ups.

Conclusion

Surgical resection of the cranial nerves CMs is appropriate when progressive neurological deficits are present. If the lesion is originated from within the nerve, we suggest resection of the involved nerve and performing anastomosis. Novel MRI sequences might help surgeons to be prepared for such cases and fibrin glue can serve as an appropriate tool to perform anastomosis when end-to-end sutures are impossible to perform.

Outcome of intracerebral cavernoma treated by Gamma Knife radiosurgery based on a double-blind assessment of treatment indication

BACKGROUND

The benefit and the risk profile of Gamma Knife radiosurgery (GKRS) for intracerebral cavernoma remains incompletely defined in part due to the natural history of low incidence of bleeding and spontaneous regression of this vascular malformation. In this study, we retrieved cases from a prospectively collected database to assess the outcome of intracerebral cavernoma treated with GKRS using a double blinded review process for treatment.

METHODS

From 2003 to 2018, there were 94 cases of cavernoma treated by GKRS in the doubly blinded assessments by two experienced neurological and approved for GKRS treatment. All the patients received GKRS with margin dose of 11-12 (Gray) Gy and afterwards were assessed for neurological outcome, radiologic response, and quality of life.

RESULTS

The median age of the patients was 48 (15-85) years with median follow up of 77 (26-180) months post SRS. The mean target volume was 1.93 ± 3.45 cc. In those who has pre-SRS epilepsy, 7 of 16 (43.7%) achieved seizure freedom (Engel I/II) and 9 of 16 (56.3%) achieved decreased seizures (Engel III) after SRS. Rebleeding occurred in 2 cases (2.1%) at 13 and 52 months post SRS. The radiologic assessment demonstrated 20 (21.3%) cases of decreased cavernoma volume, 69 (73.4%) were stable, and 5 (7.3%) increased size. Eighty-seven of 94 (92.5%) cases at the last follow up achieve improvement in their quality of life, but 7 cases (7.4%) showed a deterioration. In statistical analysis, the effective seizure control class (Engel I/II) was highly correlated with patient harboring a single lesion (p < 0.05) and deep seated location of the cavernoma (p < 0.01). New neurological deficits were highly correlated with decreased mental (p < 0.001) and physical (p < 0.05) components of quality of life testing, KPS (p < 0.001), deep seated location (p < 0.01), and increased nidus volume (p < 0.05). Quality of life deterioration either in physical component (p < 0.01), mental component (p < 0.01), and KPS (p < 0.05) was highly correlated with increased cavernoma volume.

CONCLUSION

Low margin dose GKRS for intracerebral cavernoma offers reasonable seizure control and improved quality of life while conferring a low risk of treatment complications including adverse radiation effect.

Anterior transpetrosal resection of the lower ventral pontine cavernous malformation: A technical case report with operative video

Background

Surgical treatment of pontine cavernous malformations (CMs) is challenging due to the anatomical difficulties and potential risks involved. We successfully applied an anterior transpetrosal approach (ATPA) to remove a lower ventral pontine CM, and herein we discuss the outline of our procedure accompanied by a surgical video.

Case Description

A 50-year-old woman presenting with progressively worsening diplopia was urgently admitted to our hospital. Preoperative images showed a lower ventral pontine CM compressing the corticospinal tract posteriorly. Considering the location of the CM, we determined that an ATPA was the appropriate approach to achieve a more anterolateral trajectory. We performed extradural anteromedial petrosectomy and penetrated the brainstem from the point just below the anterior inferior cerebellar artery and above the root exit zone of the abducens nerve, which might be located in the somewhat lowest border of actual maneuverability in the ATPA. Maneuverability through this corridor was sufficient without hindering and darkening the high magnification microscopic view, as demonstrated in our surgical video.

Conclusion

This report demonstrates surgical treatment of a lower ventral pontine CM using the ATPA. The surgical video we present provides information that is useful for understanding this technique's maneuverability and working window.

Transcondylar Approach for Resection of Medullary Cavernous Malformation: 2-Dimensional Operative Video

Cavernous malformations located within the brainstem present with a high rate of neurological symptoms and carry a more aggressive course in both pediatric and adult populations.1,2 Cavernomas within the medulla are the rarest form, representing only 5% of all brainstem lesions.3 Repeated hemorrhage of brainstem cavernomas is associated with significant and cumulative neurological deficits and thus requires treatment.4 Microsurgical resection has become the optimal mode of treatment with the aim of resecting the live malformation and not merely the multiaged, organized hematoma.4 This is best achieved by approaching the cavernoma at the location where it projects to the surface and entering the lesion through a safe brainstem anatomic zone. For ventrally located lesions in the medulla, a transcondylar skull base approach provides a direct trajectory to the entry zone through a short surgical distance without the need to manipulate or retract neurovascular structures.5-8 Neuronavigation and intraoperative neurophysiological monitoring of somatosensory evoked potential, motor, and lower cranial nerves are adjuncts to increase patient safety. Radiosurgery for the treatment of brainstem cavernous malformations has been proposed; however, it demonstrates high risk and variable and often poor response rates.9 We present a surgical video demonstrating the transcondylar approach and resection of a medullary cavernoma in a 54-yr-old woman who has had multiple known prior hemorrhages and presented with a new onset of facial numbness and weakness, ataxia, and left body sensory loss. The patient consented to surgery and to photograph publication.  Images at 1:28, 1:43 (left), 2:02 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997,5 with permission.  Images at 1:43 (right) from Arnautovic et al,8 with permission from JNSPG.

A comparative analysis of the modified Rankin Scale, Karnofsky Performance Status and Kurtzke expanded disability status scale in the perioperative management of patients with brainstem cavernous malformations

BACKGROUND

The neurological conditions of brainstem cerebral cavernous malformation (BCM) patients are usually ascertained using Karnofsky Performance Status (KPS) or the modified Rankin scale (mRS). However, these scales do not reflect slight changes in brainstem function, because neither KPS nor mRS includes brainstem symptoms such as worsening of swallowing or diplopia. The main problem when managing the BCM patients is that we can neither systematically record neurological changes nor conduct clinical outcome investigations of BCM due to the lack of an adequately detailed assessment system.

PURPOSE

We investigated the usefulness of the Kurtzke expanded disability status scale (EDSS), which is already in widespread clinical use for multiple sclerosis because it provides certainty in evaluating brainstem symptoms.

METHODS

We retrospectively analyzed neurological transitions in surgical BCM cases using the modified Rankin scale (mRS), Karnofsky performance status (KPS), and EDSS. We compared each neurological score transition, and determined which scale allows the most accurate recording of neurological changes in patients.

RESULTS

We proposed lesion removal for patients who showed both neurological deterioration and lesion enlargement caused by re-bleeding, and the surgery was accepted by 10 patients. EDSS allowed us to assess patient status more accurately than KPS or mRS particularly during the perioperative period. In the statistical analysis, only EDSS differed significantly during the period between the initial proposal of surgery and the immediate preoperative period.

CONCLUSION

Our results suggest EDSS to be superior for managing BCM patients, as compared to KPS and mRS. Thus, EDSS may serve as an alternative scale for assessing BCM patients.

Supracerebellar Infratentorial Infratrochlear Trans-Quadrangular Lobule Approach to Pontine Cavernous Malformations

BACKGROUND

Brainstem cavernous malformations with symptomatic hemorrhage have a poor natural history. Those without a pial or ependymal presentation are often observed given the morbidity of resection. Surgical removal is considered only in patients with accessible lesions that have repeated symptomatic hemorrhagic.

OBJECTIVE

To describe a novel supracerebellar infratentorial infratrochlear trans-quadrangular lobule approach to safely resect lesions in the upper pons.

METHODS

We use a hybrid paramedian/lateral suboccipital craniotomy in the gravity-dependent supine position. Opening the cerebellomesencephalic fissure over the tentorial surface of the cerebellum brings the trochlear nerve, branches of the superior cerebellar artery, and the quadrangular lobule of the cerebellum into view. Removal of small a portion of the quadrangular lobule defines an entry point on the superomedial aspect of the middle cerebellar peduncle, and a surgical trajectory aimed superior to inferior.

RESULTS

A total of 6 patients underwent this approach. All presented with symptomatic hemorrhage and all cavernous malformations were completely resected. Five patients were improved or unchanged with modified Rankin scale scores of 1 or 2.

CONCLUSION

The trans-quadrangular lobule approach allows safe resection of upper pontine cavernous malformations along a superior to inferior trajectory.