Cavernous malformations of the brainstem presenting in childhood: surgical experience in 40 patients

Surgical management of pontine brainstem cavernous malformations: A systematic review Emphasizing safe entry zones and clinical outcomes

OBJECTIVE

Safe entry zones (SEZs) have emerged as important corridors for accessing brainstem cavernous malformations (BSCM) while minimizing morbidity. This systematic review and meta-analysis aims to provide a comprehensive analysis of the surgical management of pontine BSCM via SEZs.

METHODS

A systematic literature search was performed in PubMed for articles reporting on the surgical management of pontine BSCM via SEZ. Data were extracted on patient demographics, clinical presentation, BSCM characteristics, surgical approach, use of SEZs, and clinical outcomes.

RESULTS

Fifteen studies with a total of 78 patients were included. The cohort was 62.8 % female with an average age of 37.62 ± 14.7 years. The most common presenting symptoms varied based on BSCM location within the pons. The two most common BSCM locations were peritrigeminal (24.4 %) and middle peduncle (10.3 %). The most frequently used surgical approach was the retrosigmoid approach (41.0 %), and the most commonly utilized SEZ was the lateral pontine zone (52.2 %). Gross total resection was achieved in 69.2 % of cases. Good clinical outcome (follow-up mRS < 2) was observed in 64.1 % of patients, with clinical deterioration observed in 7.7 %.

CONCLUSION

Surgical resection of pontine BSCM can be performed with acceptable morbidity and mortality rates when utilizing SEZs and careful preoperative planning. The lateral pontine, supratrigeminal, and peritrigeminal SEZs are associated with high rates of complete resection and improved neurological outcomes. Future studies with standardized reporting and longer follow-ups are needed to further refine surgical techniques and patient selection.

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.

Brainstem cavernous hemangioma with improvement of Holmes tremor on excision

An 8-year-old boy presenting with left-angle paralysis, tremor in upper and lower extremities, and diplopia was diagnosed with hemorrhage from a mesencephalic cavernous hemangioma. He underwent hemangiomectomy through the occipital transtentorial approach 4 weeks post-hemorrhage, after which Holmes tremor (HT) markedly reduced. A year later, hemangioma has not recurred; he is now independent in his daily activities. Early intervention in the subacute stage allows for the complete removal of brainstem cavernomas (BSCs), with minimal risk of complications or sequelae. Proper timing and surgical approach for BSCs can prevent re-bleeding and improve HT after an initial hemorrhage, without any lasting negative consequences.

Outcomes after surgical and nonsurgical treatment of pediatric cerebral cavernous malformation

Importance

Pediatric cerebral cavernous malformation (CCM) is a rarely encountered vascular entity. Comparative study on surgical excision and nonsurgical management outcomes of CCM in pediatrics is limited.

Objective

To determine the demographic characteristics, hemorrhage rate, and long-term outcomes of pediatric patients with CCM.

Methods

A retrospective study of pediatric patients with CCM in Chinese PLA General Hospital was conducted between January 2004 and January 2019. We compared the clinical characteristics, radiological features, and outcomes of the surgical and nonsurgical groups.

Results

Seventy-nine children were included, with 69.6% being boys, and the average age was 11.8 ± 5.5 years. The annual retrospective hemorrhagic rate was 5.7% per patient per year. Fifty-six children (70.9%) underwent surgical excision, and they were more likely to present with seizure symptoms (P = 0.011), have a higher proportion of larger lesion size (P = 0.008), less likely to have durations ≤10 days (P = 0.048), and less likely to have supratentorial deep CCM (P = 0.014) compared to children who received nonsurgical management. Total resection was achieved in most surgical cases (55, 98.2%). During the 143.9 ± 50.8 months of follow-up, 44 patients (78.6%) achieved improvement, 12 patients (17.8%) remained the same, and two (3.6%) experienced worsening. In the nonsurgical management group, 14 children (60.9%) experienced symptom improvement, eight (34.8%) remained the same, and one (4.3%) worsened, with a re-hemorrhagic risk of 8.7%.

Interpretation

Surgical removal of pediatric CCM can eliminate the risk of hemorrhage and lead to satisfactory outcomes. For children undergoing nonsurgical management, long-term close monitoring is essential due to the life-long risk of hemorrhage.

Identifying potential (re)hemorrhage among sporadic cerebral cavernous malformations using machine learning

The (re)hemorrhage in patients with sporadic cerebral cavernous malformations (CCM) was the primary aim for CCM management. However, accurately identifying the potential (re)hemorrhage among sporadic CCM patients in advance remains a challenge. This study aims to develop machine learning models to detect potential (re)hemorrhage in sporadic CCM patients. This study was based on a dataset of 731 sporadic CCM patients in open data platform Dryad. Sporadic CCM patients were followed up 5 years from January 2003 to December 2018. Support vector machine (SVM), stacked generalization, and extreme gradient boosting (XGBoost) were used to construct models. The performance of models was evaluated by area under receiver operating characteristic curves (AUROC), area under the precision-recall curve (PR-AUC) and other metrics. A total of 517 patients with sporadic CCM were included (330 female [63.8%], mean [SD] age at diagnosis, 42.1 [15.5] years). 76 (re)hemorrhage (14.7%) occurred during follow-up. Among 3 machine learning models, XGBoost model yielded the highest mean (SD) AUROC (0.87 [0.06]) in cross-validation. The top 4 features of XGBoost model were ranked with SHAP (SHapley Additive exPlanations). All-Elements XGBoost model achieved an AUROCs of 0.84 and PR-AUC of 0.49 in testing set, with a sensitivity of 0.86 and a specificity of 0.76. Importantly, 4-Elements XGBoost model developed using top 4 features got a AUROCs of 0.83 and PR-AUC of 0.40, a sensitivity of 0.79, and a specificity of 0.72 in testing set. Two machine learning-based models achieved accurate performance in identifying potential (re)hemorrhages within 5 years in sporadic CCM patients. These models may provide insights for clinical decision-making.

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.

[Microanatomical Investigation of the Subtemporal Transtentorial Approach]

Objective

To study the microanatomic structure of the subtemporal transtentorial approach to the lateral side of the brainstem, and to provide anatomical information that will assist clinicians to perform surgeries on the lateral, circumferential, and petroclival regions of the brainstem.

Methods

Anatomical investigations were conducted on 8 cadaveric head specimens (16 sides) using the infratemporal transtentorial approach. The heads were tilted to one side, with the zygomatic arch at its highest point. Then, a horseshoe incision was made above the auricle. The incision extended from the midpoint of the zygomatic arch to one third of the mesolateral length of the transverse sinus, with the flap turned towards the temporal part. After removing the bone, the arachnoid and the soft meninges were carefully stripped under the microscope. The exposure range of the surgical approach was observed and the positional relationships of relevant nerves and blood vessels in the approach were clarified. Important structures were photographed and the relevant parameters were measured.

Results

The upper edge of the zygomatic arch root could be used to accurately locate the base of the middle cranial fossa. The average distances of the star point to the apex of mastoid, the star point to the superior ridge of external auditory canal, the anterior angle of parietomastoid suture to the superior ridge of external auditory canal, and the anterior angle of parietomastoid suture to the star point of the 10 adult skull specimens were 47.23 mm, 45.27 mm, 26.16 mm, and 23.08 mm, respectively. The subtemporal approach could fully expose the area from as high as the posterior clinoid process to as low as the petrous ridge and the arcuate protuberance after cutting through the cerebellar tentorium. The approach makes it possible to handle lesions on the ventral or lateral sides of the middle clivus, the cistern ambiens, the midbrain, midbrain, and pons. In addition, the approach can significantly expand the exposure area of the upper part of the tentorium cerebelli through cheekbone excision and expand the exposure range of the lower part of the tentorium cerebelli through rock bone grinding technology. The total length of the trochlear nerve, distance of the trochlear nerve to the tentorial edge of cerebellum, length of its shape in the tentorial mezzanine, and its lower part of entering into the tentorium cerebelli to the petrosal ridge were (16.95±4.74) mm, (1.27±0.73) mm, (5.72±1.37) mm, and (4.51±0.39) mm, respectively. The cerebellar tentorium could be safely opened through the posterior clinoid process or arcuate protrusion for localization. The oculomotor nerve could serve as an anatomical landmark to locate the posterior cerebral artery and superior cerebellar artery.

Conclusion

Through microanatomic investigation, the exposure range and intraoperative difficulties of the infratemporal transtentorial approach can be clarified, which facilitates clinicians to accurately and safely plan surgical methods and reduce surgical complications.

Clinical presentation, natural history, and outcomes for infantile intracranial cavernous malformations: case series and systematic review of the literature

INTRODUCTION

Intracranial cavernous malformations (CMs) are rare vascular malformations of the central nervous system in children. Infantile patients, being a developmentally vulnerable age group, pose a special challenge for management of these lesions. We pooled data from infantile patients diagnosed at our institution and individual cases published in the literature to provide input towards therapeutic decision-making.

METHODS

A systematic search of PubMed, MEDLINE, Embase, and Scopus was performed in accordance with PRISMA guidelines to identify all reported cases of intracranial CMs in the literature for infantile patients aged ≤ 2 years. In addition, cases from our institution diagnosed between 2010 and 2020 were also included. Individual cases were pooled and analyzed for clinical presentation, natural history, and outcomes from conservative and surgical management.

RESULTS

A total of 36 cases were included, of which 32 were identified from the literature. Median age at presentation was 14 months (range: 2 days to 24 months) months; 53% (n = 19) were females. Most cavernomas (64%, 23/36) were supratentorial, while 30% (n = 11) were located in brainstem and 5.5% (n = 2) in the cerebellum. With the exception of one patient, all cases were reported to be symptomatic; seizures (n = 15/31, 48.3%) and motor deficits (n = 13/31, 42%) were the most common symptom modalities. A total of 13 patients were managed conservatively upon initial presentation. No symptomatic hemorrhages were observed during 26 total person-years of follow-up. A total of 77% (28/36) underwent surgery; either upfront (23/28, 82%) at initial presentation or following conservative management. Among 12 patients who had preoperative seizures, 11/12 (91.6%) achieved seizure freedom post-resection. Among 7 patients who presented with hemiparesis preoperatively, 5 (71%) demonstrated some improvement, while 1 remained unchanged, and another patient with a brainstem cavernous malformation had worsening of motor function postoperatively. Postoperative recurrence was noted in 3 cases (3/27, 11%).

CONCLUSION

Annual risk of repeat hemorrhage may be low for infantile patients with intracranial cavernous malformations; however, better follow-up rates and higher number of cases are needed to make a definitive assertion. Surgical resection may be associated with high rates of epilepsy cure and provide improvement in neurological function in a select number of cases.

Cerebral cavernous malformations: Typical and atypical imaging characteristics

Cavernous malformations (CMs) are benign vascular malformations that maybe seen anywhere in the central nervous system. They are dynamic lesions, growing or shrinking over time and only rarely remaining stable. Size varies from a few millimeters to a few centimeters. CMs can be sporadic or familial, and while most of them are congenital, de novo and acquired lesions may also be seen. Etiology is still unknown. A genetic molecular mechanism has been proposed since a cerebral cavernous malformation gene loss of function was found in both familial and sporadic lesions. Additionally, recent studies suggest that formation of CMs in humans may be associated with a distinctive bacterial gut composition (microbioma). Imaging is fairly typical but may vary according to age, location, and etiology. Follow-up is not well established because CMs patients have a highly unpredictable clinical course. Angiogenic and inflammatory mechanisms have been implicated in disease activity, as well as lesional hyperpermeability and iron deposition. Imaging and serum biomarkers of these mechanisms are under current investigation. Treatment options, including surgery or radiosurgery, are not well defined and are dependent upon multiple factors, including clinical presentation, lesion location, number of hemorrhagic events, and medical comorbidities. Our purpose is to review the imaging features of CMs based on their size, location, and etiology, as well as their differential diagnosis and best imaging approach. New insights in etiology will be briefly considered. Follow-up strategies, including serum and imaging biomarkers, and treatment options will also be discussed.

Functional outcome after initial and multiple intracerebral hemorrhages in children with cerebral cavernous malformations

BACKGROUND AND PURPOSE

We aimed to assess the course and predictors of functional outcome after single and multiple intracerebral hemorrhage (ICH) in pediatric patients with cerebral cavernous malformations (CCMs) and to conduct a risk assessment of a third bleed during the first follow-up year after second ICH.

METHODS

We included patients aged ≤18 years with complete baseline characteristics, a magnetic resonance imaging dataset, ≥1 CCM-related ICH and ≥1 follow-up examination, who were treated between 2003 and 2021. Neurological functional status was obtained using modified Rankin Scale scores at diagnosis, before and after each ICH, and at last follow-up. Kaplan-Meier analysis was performed to determine the cumulative 1-year risk of third ICH.

RESULTS

A total of 55 pediatric patients (median [interquartile range] age 12 [11] years) were analyzed. Univariate analysis identified brainstem cavernous malformation (BSCM; p = 0.019) as a statistically significant predictor for unfavorable outcome after second ICH. Outcome after second ICH was significantly worse in 12 patients (42.9%; p = 0.030) than after first ICH and in five patients (55.6%; p = 0.038) after a third ICH compared to a second ICH. Cumulative 12-month risk of rebleeding during the first year after a second ICH was 10.7% (95% confidence interval 2.8%-29.37%).

CONCLUSIONS

Pediatric patients with a BSCM have a higher risk of worse outcome after second ICH. Functional outcome improves over time after an ICH but worsens following each ICH compared to baseline or previous ICH. Second bleed was associated with neurological deterioration compared to initial ICH, and this deteriorated further after a third ICH.

Functional outcome after pediatric cerebral cavernous malformation surgery

The purpose of this study was to investigate the functional outcome following surgical resection of cerebral cavernous malformations (CCM) in pediatric patients. We screened our institutional database of CCM patients treated between 2003 and 2021. Inclusion regarded individuals younger or equal than 18 years of age with complete clinical baseline characteristics, magnetic resonance imaging dataset, and postoperative follow-up time of at least three months. Functional outcome was quantified using the modified Rankin Scale (mRS) score and assessed at admission, discharge, and last follow-up examination. The primary endpoint was the postoperative functional outcome. As a secondary endpoint, predictors of postoperative functional deterioration were assessed. A total of 49 pediatric patients with a mean age of 11.3 ± 5.7 years were included for subsequent analyses. Twenty individuals (40.8%) were female. Complete resection of the lesion was achieved in 44 patients (89.8%), and two patients with incomplete resection were referred for successive remnant removal. The mean follow-up time after surgery was 44 months (IQR: 13 - 131). The mean mRS score was 1.6 on admission, 1.7 at discharge, and 0.9 at the latest follow-up. Logistic regression analysis adjusted to age and sex identified brainstem localization (aOR = 53.45 [95%CI = 2.26 - 1261.81], p = .014) as a predictor of postoperative deterioration. This study indicates that CCM removal in children can be regarded as safe and favorable for the majority of patients, depending on lesion localization. Brainstem localization implies a high risk of postoperative morbidity and indication for surgery should be balanced carefully. Minor evidence indicates that second-look surgery for CCM remnants might be safe and favorable.

Residual and Recurrent Spinal Cord Cavernous Malformations: Outcomes and Techniques to Optimize Resection and a Systematic Review of the Literature

BACKGROUND

Intramedullary spinal cord cavernous malformations (SCCMs) account for only 5% of overall cavernous malformations (CMs). The occurrence of recurrent or residual SCCMs has not been well discussed, nor have the technical nuances of resection.

OBJECTIVE

To assess the characteristics of residual SCCMs and surgical outcomes and describe the techniques to avoid leaving lesion remnants during primary resection.

METHODS

Demographic, radiologic, intraoperative findings and surgical outcomes data for a cohort of surgically managed intramedullary SCCMs were obtained from an institutional database and retrospectively analyzed. A systematic literature review was performed using PRISMA guidelines.

RESULTS

Of 146 SCCM resections identified, 17 were for residual lesions (12%). Patients with residuals included 13 men and 4 women, with a mean age of 43 years (range 16-70). All patients with residual SCCMs had symptomatic presentations: sensory deficits, paraparesis, spasticity, and pain. Residuals occurred between 3 and 264 months after initial resection. Approaches for 136 cases included posterior midline myelotomy (28.7%, n = 39), pial surface entry (37.5%, n = 51), dorsal root entry zone (27.9%, n = 38), and lateral entry (5.9%, n = 8). Follow-up outcomes were similar for patients with primary and residual lesions, with the majority having no change in modified Rankin Scale score (63% [59/93] vs 75% [9/12], respectively, P = .98).

CONCLUSION

SCCMs may cause significant symptoms. During primary resection, care should be taken to avoid leaving residual lesion remnants, which can lead to future hemorrhagic events and neurological morbidity. However, satisfactory results are achievable even with secondary or tertiary resections.

3-Dimensional Exoscope for Far Lateral Approach to Pontomedullary Cavernous Malformation

Brainstem cavernous malformations account for 15%-18% of all central nervous system cavernomas and are histologically characterized by thin-walled, low-pressure capillaries, classically without intervening brain tissue.^1,2 Cavernomas may be sporadic, typically characterized by a single lesion, or inherited. The inherited form is most often autosomal dominant with incomplete penetrance and variable expression. Multiple cavernomas are associated with the familial form; although this is not always the case, genetic workup should be pursued.^3,4 Clinical presentation typically includes focal neurologic deficit related to hemorrhage location, seizures, and rarely obstructive hydrocephalus.^1,2 Indications for surgical management include severe or progressive neurologic dysfunction, lesion size ≥2 cm, recurring hemorrhages, and/or significant mass effect.⁵ Microsurgical resection of a cavernoma is associated with an overall 28% complication rate and perioperative neurologic morbidity upwards of 45% according to some series. Long-term surgical outcomes at 12 months are more reassuring: 84% reported their condition to have improved or remained the same, and the long-term morbidity rate is 14%.^1,6 The location of the lesion dictates the approaches available-cavernomas in the pons or medulla are commonly approached via a retrosigmoid or retrolabyrinthine approach, while more ventral pathologies in this region necessitate a far lateral approach.^1,5,7,8 In Videos 1 and 2, we describe our experience with an exoscope-assisted far lateral approach to a pontomedullary cavernoma in a 10-year-old male presenting with numerous cavernomas and confirmed gene mutation. We demonstrate the exoscope's unparalleled visualization of the anterolateral brainstem, with nominal condylar drilling. The patient and his parents consented to the procedure and publication.

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.

Stereotactic radiosurgery for cerebral cavernous malformation: comparison of hemorrhage rates before and after stereotactic radiosurgery

OBJECTIVE

Cerebral cavernous malformation (CM) is an angiographically occult vascular pathology. Although microsurgery is the gold standard treatment to control the symptoms of CM, resection carries high risk in some situations, especially eloquent areas. The objective was to evaluate annual hemorrhage rates (AHRs) before and after stereotactic radiosurgery (SRS) treatment of cerebral CM in different locations.

METHODS

A total of 195 patients (119 women and 76 men) with CM treated at the Gazi University Gamma Knife Center between April 2005 and June 2017 were analyzed. The mean ± SD follow-up period was 67.4 ± 31.1 months (range 12 days to 170 months). AHR before SRS, AHR after SRS, morbidity associated with radiation, seizure control rate after SRS, lesion volume, coexistence with developmental venous anomaly, and SRS treatment parameters were analyzed, with evaluation of radiological data and clinical charts performed retrospectively. The seizure control rate was assessed using the Engel outcome scale.

RESULTS

The AHR before SRS was 15.3%. Application of SRS to these patients significantly reduced the AHR rates to 2.6% during the first 2 years after treatment and to 1.4% thereafter. Favorable seizure control (Engel class I and II) after radiosurgery was achieved in 23 patients (88.5%) with epilepsy. Radiation-related temporary complications occurred in 15.4% of patients, and permanent morbidity occurred in 4.6%.

CONCLUSIONS

SRS is a safe and effective treatment modality for reducing the hemorrhage risk of CM. The authors suggest that SRS should be considered for the treatment of patients with CM, high surgical risks, and hemorrhage history, instead of a using a wait-and-see policy.

How can we optimize the long-term outcome in children with intracranial cavernous malformations? A single-center experience of 61 cases

The objective is to provide a treatment algorithm for pediatric patients with intracranial cavernous malformations (CMs) based on our experience. Patients < 18 years of age who were treated either surgically or conservatively at the authors' institution between 1982 and 2019 were retrospectively evaluated. A total of 61 pediatric patients were treated at the authors' institution: 39 with lobar CMs; 18 with deep CMs, including 12 in the brainstem and 6 in the basal ganglia; and 4 with CMs in the cerebellar hemispheres. Forty-two patients underwent surgery, and 19 were treated conservatively. The median follow-up time was 65 months (1-356 months). In surgically treated patients, lesions were larger (2.4 cm vs 0.9 cm, p < 0.001). In patients with lobar CMs, seizures were more common (72% vs 21%, p = 0.003) in the surgery group than in conservatively managed patients. In deep CMs, modified Rankin scale (mRS) was higher (4 vs 1, p = 0.003) in the surgery group than in conservatively treated patients. At the time of last follow-up, no differences in Wieser outcome class I were seen (86% vs 67%) in lobar CMs, and mRS scores had aligned between the treatment groups in deep CMs (1 vs 0). We encountered no new permanent neurological deficit at time of last follow-up. We propose a treatment algorithm according to lesion location and size, burden of symptoms, epilepsy workup, and further clinical course during observation. A conservative management is safe in pediatric patients with asymptomatic CMs. Gross total resection should be the aim in patients with symptomatic lobar CMs. A less aggressive approach with subtotal resection, when required to prevent neurological compromise, sustainably improves neurological outcome in patients with deep CMs.

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.

Natural Course of Cerebral Cavernous Malformations in Children: A Five-Year Follow-Up Study

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the natural course of cerebral cavernous malformations (CCM) in the pediatric population, with special emphasis on the risk of first and recurrent bleeding over a 5-year period.

METHODS

Our institutional database was screened for patients with CCM treated between 2003 and 2020. Patients ≤18 years of age with complete magnetic resonance imaging data set, clinical baseline characteristics, and ≥1 follow-up examination were included. Surgically treated individuals were censored after CCM removal. We assessed the impact of various parameters on first or recurrent intracerebral hemorrhage (ICH) at diagnosis using univariate and multivariate logistic regression adjusted for age and sex. Kaplan-Meier and Cox regression analyses were performed to determine the cumulative 5-year risk for (re)hemorrhage.

RESULTS

One hundred twenty-nine pediatric patients with CCM were analyzed. Univariate logistic regression identified brain stem CCM (odds ratio, 3.15 [95% CI, 1.15-8.63], P=0.026) and familial history of CCM (odds ratio, 2.47 [95% CI, 1.04-5.86], P=0.041) as statistically significant predictors of ICH at diagnosis. Multivariate logistic regression confirmed this correlation (odds ratio, 3.62 [95% CI, 1.18-8.99], P=0.022 and odds ratio, 2.53 [95% CI, 1.07-5.98], P=0.035, respectively). Cox regression analysis identified ICH as mode of presentation (hazard ratio, 14.01 [95% CI, 1.80-110.39], P=0.012) as an independent predictor for rehemorrhage during the 5-year follow-up. The cumulative 5-year risk of (re)bleeding was 15.9% (95% CI, 10.2%-23.6%) for the entire cohort, 30.2% (20.2%-42.3%) for pediatric patients with ICH at diagnosis, and 29.5% (95% CI, 13.9%-51.1%) for children with brain stem CCM.

CONCLUSIONS

Pediatric patients with brain stem CCM and familial history of CCM have a higher risk of ICH as mode of presentation. During untreated 5-year follow-up, they revealed a similar risk of (re)hemorrhage compared to adult patients. The probability of (re)bleeding increases over time, especially in cases with ICH at presentation or brain stem localization.

Recurrent brainstem cavernous malformations following primary resection: blind spots, fine lines, and the right-angle method

OBJECTIVE

Proximity of brainstem cavernous malformations (BSCMs) to tracts and cranial nerve nuclei make it costly to transgress normal tissue in accessing the lesion or disrupting normal tissue adjacent to the lesion in the separation plane. This interplay between tissue sensitivity and extreme eloquence makes it difficult to avoid leaving a remnant on occasion. Recurrences require operative intervention, which may increase morbidity, lengthen recovery, and add to overall costs. An approximately 20-year experience with patients with recurrent BSCM lesions following primary microsurgical resection was reviewed.

METHODS

A prospectively maintained database of 802 patients who underwent microsurgical resection of cerebral cavernous malformations during 1997-2018 was queried to identify 213 patients with BSCMs. A retrospective chart review was conducted for patients with recurrent BSCM after primary resection who required a second surgery.

RESULTS

Fourteen of 213 patients (6.6%) underwent repeat resection for recurrent BSCM. Thirty-four hemorrhagic events were observed among these 14 patients over 576 patient-years (recurrent hemorrhage rate, 5.9% per year; median discrete hemorrhagic events, 2; median time to rehemorrhage, 897 days). BSCM occurred in the pons in 10 cases, midbrain in 2 cases, and medulla in 2 cases. A blind spot in the operative corridor was the most common cause of residual BSCM (9 patients). All recurrent BSCMs were removed completely, although 2 patients each required 2 operations to treat recurrence. Twelve patients had unchanged or improved modified Rankin Scale scores at last clinical evaluation compared with admission, and 2 patients had worse scores. Recurrence was more common among patients who were operated on in the first versus the second half of the series (8.5% vs 4.7%).

CONCLUSIONS

The 6.6% rate of BSCM recurrence requiring reoperation reflects the fine lines between complete resection and recurrence and between safe and harmful surgery. The detection of remnants is difficult postoperatively and remains so even at 6 months when the resection bed has healed. The 5.9% annual hemorrhage risk associated with recurrent BSCM in this experience is consistent with that reported for unoperated BSCMs. The right-angle method helps to anticipate blind spots and meticulously inspect the resection cavity for residual BSCM during surgery. A low percentage of recurrent BSCM (5%-10%) ensures ongoing effort toward an acceptable balance of safety and completeness.

Mortality in Patients with Brainstem Cavernous Malformations

OBJECTIVE

Brainstem cavernous malformations (BSCM)-associated mortality has been reported up to 20% in patients managed conservatively, whereas postoperative mortality rates range from 0 to 1.9%. Our aim was to analyze the actual risk and causes of BSCM-associated mortality in patients managed conservatively and surgically based on our own patient cohort and a systematic literature review.

METHODS

Observational, retrospective single-center study encompassing all patients with BSCM that presented to our institution between 2006 and 2018. In addition, a systematic review was performed on all studies encompassing patients with BSCM managed conservatively and surgically.

RESULTS

Of 118 patients, 54 were treated conservatively (961.0 person years follow-up in total). No BSCM-associated mortality was observed in our conservatively as well as surgically managed patient cohort. Our systematic literature review and analysis revealed an overall BSCM-associated mortality rate of 2.3% (95% CI: 1.6-3.3) in 22 studies comprising 1,251 patients managed conservatively and of 1.3% (95% CI: 0.9-1.7) in 99 studies comprising 3,275 patients with BSCM treated surgically.

CONCLUSION

The BSCM-associated mortality rate in patients managed conservatively is almost as low as in patients treated surgically and much lower than in frequently cited reports, most probably due to the good selection nowadays in regard to surgery.

Spontaneous Intracranial Hemorrhage: A Sign of Cavernous Angioma Diagnosis in Pediatric Age Group

Cerebral cavernous malformation (CCM) is a developmental abnormality of blood vessels that supply the brain. It is composed of large, adjacent capillaries which contain little or no neural tissue. They mostly occur in the supratentorial region. However, the occurrence of these vascular lesions can be seen at different sites of the central nervous system (CNS). The prevalence of CCM is estimated to be 0.4% in the general population and among the affected patients, 18.7% have multiple lesions. However, about 30-50% of CCM cases are asymptomatic and are found incidentally. Here we report a case of an eight-year-old girl with a massive hemorrhagic presentation of a left parietooccipital CCM.

Holmes tremor in a monocentric series of resected brainstem cavernomas

OBJECT

Several scientific papers report clinical symptoms, indications, complications and outcomes of brainstem cavernous malformation (BSCM) surgery without reporting on the occurrence of postoperative Holmes tremor (HT). Our purpose is to report our experience with HT in a monocentric series of resected brainstem cavernomas.

METHODS

We reviewed all the BSCM surgical records between 2002 and 2018 at Saint-Luc University Hospital's Department of Neurosurgery, Brussels and selected patients developing HT postoperatively. Patients' demographics, symptoms, pre- and postoperative imaging, recurrence and complications were analysed. A PubMed literature review was performed to compare our results with those in the existing literature.

RESULTS

In a total series of 18 resected BSCM, 5 patients: 1 male and 4 females, with a median age of 51 years (range 29-59 years), developed HT. The median preoperative mRS score was 2 (range 1-4). GTR was achieved in all patients without surgery-related death. BSCM were located in the mesencephalon in 4 patients (80%) who developed HT. Tremor was noticed between ten days and one year after surgery. One patient saw significant improvements to the point of stopping treatment. The median follow-up period was 2 years (range 1-14 years). At the last follow-up, 40% of our patients showed a worse mRS score, 40% stayed unchanged, and 20% improved.

CONCLUSION

We are reporting an original single-center series of patients suffering from HT after BSCM surgery. The risk for HT after surgery is significant for midbrain BSCM. A spontaneous favorable evolution is possible.

Ruptured pontine cavernomas in infants: a report of two cases

BACKGROUND

Cavernous malformations (CMs) are either congenital or acquired vascular lesions comprised of sinusoid spaces filled with either blood or its breakdown products. They possess a relatively reduced risk of hemorrhage, yet placement within the posterior fossa and especially the brainstem heightens their likelihood to rupture, making them a likely cause of permanent and debilitating neurological deficit, as well as a veritable surgical challenge. Although the incidence of rupture varies with age among reported case series, it is undoubtable that the severity of this occurrence is the highest while the brain is as its most vulnerable period, i.e. during infancy.

CASE PRESENTATIONS

We present two patients, both female, 6.5- and 5-months-old respectively, who presented with brainstem hemorrhage from CM. They suffered from a sudden onset of hemiparesis and were subjected to surgical removal of their lesions and resulting hematomas. Both patients were discharged in a favorable neurological status and are currently alive and in good health.

CONCLUSION

Microsurgical treatment of brainstem CMs in infants is not only possible with minimal deficit, but also advisable if the lesions are symptomatic. Nevertheless, this requires substantial patience and experience to prevent significant loss of blood and injury to the structures of the posterior fossa. We argue that the safest method to prevent further damage from brainstem CM rebleed is to remove these lesions shortly after the initial hemorrhage.

Microsurgery vs. Gamma Knife Radiosurgery for the Treatment of Brainstem Cavernous Malformations: A Systematic Review and Meta-Analysis

Background: Brainstem cavernous malformations (BSCMs) are a subset of cerebral cavernous malformations with precarious locations and potentially devastating clinical courses. The effects and outcomes of treating BSCMs by microsurgery or gamma knife radiosurgery (GKRS) vary across studies.

Methods: We searched the Medline, Web of Science, The Cochrane Library, PubMed, and China Biology Medicine disc databases for original articles published in peer-reviewed journals of cohort studies reporting on 20 or more patients of any age with BSCMs with at least 80% completeness of follow-up.

Results: We included 43 cohorts involving 2,492 patients. Both microsurgery (RR = 0.04, 95% CI 0.01–0.16, P < 0.01) and GKRS (RR = 0.11, 95% CI 0.08–0.16, P < 0.01) demonstrated great efficacy in reducing the rehemorrhage rate after treatment for BSCMs. The incidence rates of composite outcomes were 19.8 (95% CI 16.8–22.8) and 15.7 (95% CI 11.7–19.6) after neurosurgery and radiosurgery, respectively. In addition, we found statistically significant differences in the median numbers of patients between neurosurgical and radiosurgical cohorts in terms of symptomatic intracranial hemorrhage (ICH; neurosurgical cohorts: median 0, range 0–33; radiosurgical cohorts: median 4, range 1–14; P < 0.05) and persistent focal neurological deficit (FND; neurosurgical cohorts: median 5, range 0–140; radiosurgical cohorts: median 1, range 0–3; P < 0.05).

Conclusions: The reported effects of treating BSCMs by microsurgery or GKRS are favorable for reducing recurrent hemorrhage from BSCMs. Patients in the neurosurgery cohort had a lower incidence of symptomatic ICH, while patients in the radiosurgical cohort had a lower incidence of persistent FND.

Surgery for Brainstem Cavernous Malformations: Association between Preoperative Grade and Postoperative Quality of Life

BACKGROUND

Brainstem cavernous malformations (BSCMs) are associated with substantial neurologic morbidity, but the literature on quality of life (QoL) after surgical treatment is limited. There is a need for validating the clinical utility of current grading scales for cavernous malformations.

OBJECTIVE

To assess outcome of surgery for BSCMs and validate how outcome is associated with current grading scales for cavernous malformations.

METHODS

We retrospectively reviewed a single-surgeon series of patients with BSCM treated surgically during a 10-yr period. Outcome was categorized according to modified Rankin Scale (mRS), and QoL was assessed by interviewing patients using Short Form 36 (SF-36) Health Survey and comparing results with the normative population. The mRS and QoL were correlated with the Lawton BSCM grading scale and with the Zabramski classification of cavernous malformations.

RESULTS

The study included 22 patients (12 males and 10 females; median age 58 yr). No mortality related to the BSCM surgery occurred, and none were in vegetative state. In SF-36, 70% of patients reported a physical and mental functioning noninferior compared to the general population of comparative age and gender group. There was a significant positive correlation between the Lawton BSCM grading and the postoperative mRS score and QoL.

CONCLUSION

Outcome of surgery for BSCM was good, as assessed by mRS and QoL. The Lawton grading scale for BSCMs correlated significantly with the postoperative mRS score and QoL, suggesting this grading scale may become a useful clinical tool for treatment prognostication at the individual level.

Natural history of incidentally diagnosed brainstem cavernous malformations in a prospective observational cohort

There was a lack of natural history of incidental brainstem cavernous malformations (CMs), hemorrhage of which would lead to severe neuropathies. The study aimed to evaluate the prospective hemorrhage rate and neurological outcome of the disease. This prospective cohort included patients with incidental brainstem CMs referred to our institute from 2009 to 2015. The diagnosis was confirmed based on the patients' complain, physical examination, and radiographic evidence. Clinical data were collected, scheduled follow-up was performed, and the independent risk factors were identified by multivariate analysis. This cohort included 48 patients (22 female, 45.8%). The median follow-up duration was 60.7 months, and 13 prospective hemorrhages occurred within 244.0 patient-years yielding an annual hemorrhage rate of 5.3%. The hemorrhage-free survival at 1 and 5 years was 91.6% and 80.6%. Age ≥ 55 years (hazard ratio (HR) = 8.59, p = 0.003), lesion size (per 1-mm increase) (HR = 3.55, p = 0.041), developmental venous anomaly (HR = 10.28, p = 0.017), and perilesional edema (HR = 4.90, p = 0.043) were independent risk factors for hemorrhage. Seven patients (14.6%) received surgical resection, and the other 41 patients remained under observation. Neurological function was improved in 22 patients (45.8%), unchanged in 19 (39.6%), and worsened in 7 (14.6%). Prospective hemorrhage (odds ratio = 14.95, p = 0.037) was the only independent risk factor for worsened outcomes. The natural history of incidental brainstem CMs seemed to be acceptable with improved/unchanged outcomes in most patients (85.4%). These results improved our understanding of the disease, and the future study of a large cohort was required to verify our findings.

Interpeduncular Sulcus Approach to the Posterolateral Pons

OBJECTIVE

In this article, we describe a new safe entry point for the posterolateral pons.

METHODS

To show the adjacent anatomy and measure the part of the interpeduncular sulcus that can be safely accessed, we first performed a review of the literature regarding the pons anatomy and its surgical approaches. Thereafter, 1 human cadaveric head and 15 (30 sides) human brainstems with attached cerebellums were bilaterally dissected with the fiber microdissection technique. A clinical correlation was made with an illustrative case of a dorsolateral pontine World Health Organization grade I astrocytoma.

RESULTS

The safe distance for accessing the interpeduncular sulcus was found to extend from the caudal end of the lateral mesencephalic sulcus to the point at which the intrapontine segment of the trigeminal nerve crosses the interpeduncular sulcus. The mean distance was 8.2 mm (range, 7.15-8.85 mm). Our interpeduncular sulcus safe entry zone can be exposed through a paramedian infratentorial supracerebellar approach. When additional exposure is required, the superior portion of the quadrangular lobule of the cerebellar hemispheric tentorial surface can be removed. In the presented case, surgical resection of the tumor was performed achieving a gross total resection, and the patient was discharged without neurologic deficit.

CONCLUSIONS

The interpeduncular sulcus safe entry zone provides an alternative direct route for treating intrinsic pathologic entities situated in the posterolateral tegmen of the pons between the superior and middle cerebellar peduncles. The surgical corridor provided by this entry point avoids most eloquent neural structures, thereby preventing surgical complications.

Outcomes of basal ganglia and thalamic cavernous malformation surgery: A meta-analysis

Surgical resection of basal ganglia (BG) and thalamic cavernous malformations (CMs) has not yet become standardized in the field of neurosurgery due to the eloquent location of these lesions and the relative paucity of literature on the subject. This review presents a consolidation of the available literature on outcomes and complication rates after surgical resection of these lesions. A systematic literature review was performed via PubMed database for articles published between 1985 and 2019. Studies comprising ≥2 patients receiving surgery for BG or thalamic CMs with available follow-up data were included. Pooled data included patient demographics, CM preoperative characteristics, and surgical outcomes Twenty studies comprising 227 patients were included for analysis. Complete resection was achieved in 94.7% (fixed-effects pooled estimate [FE]: 94.9%[91.0%-97.8%]; random-effects pooled estimate [RE]: 90.0%[79.8%-96.9%]), and hemorrhage of incompletely resected CMs occurred in 50% (FE: 55.9%[25.9%-83.6%]; RE: 55.9%[25.9%-83.6%]) of patients. Early morbidity was observed in 24.0% (FE: 24.9%[17.8%-32.6%]; RE: 24.9%[17.8%-32.6%]). At final follow-up, 67.3% (FE: 67.7%[58.8%-76.0%]; RE: 67.8%[52.2%-81.6%]) and 20.6% (FE: 20.6%[13.6%-28.6%]; RE: 20.9%[9.8%-34.9%]) had improvement and stability of preoperative symptoms, respectively. Mortality rate was 1.3% (FE: 2.3%[0.6%-5.1%]; RE: 2.3%[0.6%-5.1%]). Therefore, high cure rates with low rates of postoperative morbidity can be achieved in BG or thalamic CM surgery. Most patients had improved neurological function at final follow-up. Complete resection should be attempted to reduce rates of repeat hemorrhage.

Supratentorial cavernoma and epilepsy: Experience with 23 cases and literature review

Background

The current study aimed to assess the role of microsurgical treatment of patients with supratentorial cavernoma with epilepsy based on analysis of our patients.

Methods

This retrospective study included 23 patients with supratentorial cavernoma on computed tomography (CT) scan and magnetic resonance imaging (MRI) of the brain admitted to the Department of Neurosurgery, Assiut University Hospitals (single tertiary hospital) between January 2014 and January 2018 (minimum 12-month follow-up). Deep-seated hemispheric and multiple cavernomas were excluded. Radiographs and hospital data of the patients were gathered and analyzed. All patients underwent the surgical procedure by one experienced neurosurgeon and the diagnosis was confirmed by pathologic evaluation.

Results

A total of 23 patients underwent surgical intervention consist of 15 (65%) men and 8 (35%) women. Their age varies from 11 to 59 year with an average of 36.6 years. All patients presented with seizure. The supratentorial cavernomas were located commonly in temporal lobes; 9 patients (39.1%). 19 (83%) of cavernoma located in the left side. 18 (78%) of cavernoma had a size <2 cavernoma. Complete excision was confirmed in postoperative investigations (CT and MRI brain images). All 10 patients with only one seizure preoperatively were seizure free at follow-up. Of nine patients who had experienced between two and five seizures preoperatively, 7 (78%) were seizure free, and of four patients with numerous seizures preoperatively, 3 (75%) were seizure free.

Conclusion

Our retrospective population study demonstrates an insight into the supratentorial cavernoma and suggests that microsurgical removal of the symptomatic cavernoma is generally accepted as the most effective and safe method.

Contemporary radiosurgery of cerebral cavernous malformations: Part 1. Treatment outcome for critically located hemorrhagic lesions

OBJECTIVE

Long-term benefits of radiosurgery (RS) applying modern protocols to treat cavernous malformations (CMs) remain unclear as critics may consider the decrease in the rebleed rate generally observed 2 years after RS as a reflection of the lesion's natural history. The authors adopted an early intention-to-treat attitude since rehemorrhage from deep-seated CMs ultimately leads to stepwise neurological deterioration. The safety of this early policy was previously demonstrated. Here, the authors revisit their current practice in a larger population with a longer follow-up time to assess the long-term effects of RS in the context of current knowledge on the natural history of CMs.

METHODS

The authors conducted a retrospective analysis of 210 patients with 210 hemorrhagic CMs located in the brainstem, thalamus, or basal ganglia and treated with Gamma Knife RS between 1995 and 2014. Two hundred six patients had available follow-up, which was a median of 5.5 years (range 1-20 years). The median age was 37 years (0.5-77 years) at presentation and 43 (2-78) at treatment. One hundred twenty-seven CMs had bled once and 83 had had multiple hemorrhages prior to treatment.

RESULTS

The lifetime annual bleed rate of CMs having a single hemorrhage prior to treatment was 2.4% per lesion. The hemorrhage rate stabilized at 1.1% after a temporary increase of 4.3% within the first 2 years after RS. The annual pretreatment hemorrhage rate was 2.8% for the lesions having multiple bleeds prior to RS with a pretreatment rebleed rate of 20.7% and with a modest gradual decrease within the first 5 years and remaining stable at 11.55% thereafter. The rebleed rate fell to 7.9% for the first 2 years after RS and declined further to 1.3% thereafter, which was significantly lower than the long-term pretreatment rebleed risk. The rate of hemorrhage-free survival remained 86.4% and 75.1% (1 patient each) at 20 years after RS in the single- and multiple-bleed groups, respectively.Pretreatment hemorrhages resulted in permanent deficits in 48.8% of the cases with a single bleed and in 77.1% of the cases with multiple bleeds. Both the rate and severity of deficits were significantly lower in the first group. Only mild and a low rate of permanent neurological deficits were caused either by posttreatment hemorrhages (7.4%) or by radiation (7.2%). The rate of persistent morbidity in the single-bleed group remained significantly lower at the end of the study than pretreatment morbidity in the multiple-bleed group (OR 2.9, 95% CI 1.6-5.3). Lesion-specific mortality was < 1%.

CONCLUSIONS

The hemorrhage rate of CMs after RS remained low after the first 2 years during the longer follow-up period. The benefit of early treatment appears to be confirmed by the study results as repeated hemorrhages carry the risk of significantly higher cumulative morbidity than the morbidity associated with RS.

Microsurgical Management of Midbrain Cavernous Malformations: Predictors of Outcome and Lesion Classification in 72 Patients

BACKGROUND

Due to the complex segmental organization of the brainstem, it is preferable to study midbrain cavernous malformations (MCMs) separately from pontine and medullary lesions.

OBJECTIVE

To evaluate clinical results after microsurgical removal of MCMs, assess predictors for outcome and introduce a topographical classification of MCMs.

METHODS

A retrospective study was conducted on consecutive patients who underwent MCM resection. Clinical parameters before and after surgery, morphological CM features, surgical approaches and outcomes were analyzed. MCMs were classified according to their exact location within the midbrain and their axial and sagittal extension.

RESULTS

The authors reviewed 72 patients (35 male). Lesions varied in size between 4 and 55 mm. The vast majority of patients benefited from surgery. The mean modified Rankin Scale (mRS) decreased significantly from 1.6 at admission to 1.3 at discharge and to 0.7 at follow-up (6-247 mo postoperatively). Five patients (6.9%) suffered from delayed hypertrophic olivary degeneration as visualized on magnetic resonance imaging. One male suffered from early postoperative re-bleeding that required surgical hematoma evacuation. There were no severe long tract impairment or other disabling complications, no delayed re-bleedings, and no surgical mortality.

CONCLUSION

We present a new topographic classification of MCMs that may be useful for predicting the occurrence of postoperative eye movement disorders. Other predictors of persistent oculomotor disturbances are time interval between onset of symptoms and surgery, and patient's age over 40 yr. Early surgery is recommendable in patients with oculomotor disturbances. MCM size over 18 mm, patient age over 40 yr, and poor mRS at admission are important predictors for the long-term outcome.

Surgical outcome of motor deficits and neurological status in brainstem cavernous malformations based on preoperative diffusion tensor imaging: a prospective randomized clinical trial

OBJECTIVE: Surgical management of brainstem lesions is challenging due to the highly compact, eloquent anatomy of the brainstem. This study aimed to evaluate the safety and efficacy of preoperative diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in brainstem cavernous malformations (CMs). METHODS: A prospective randomized controlled clinical trial was performed by using stratified blocked randomization. The primary eligibility criterion of the study was being a surgical candidate for brainstem CMs (with informed consent). The study enrolled 23 patients who underwent preoperative DTI/DTT and 24 patients who did not (the control group). The pre- and postoperative muscle strength of both limbs and modified Rankin Scale (mRS) scores were evaluated. Muscle strength of any limb at 12 months after surgery at the clinic visit was the primary outcome; worsened muscle strength was considered to be a poor outcome. Outcome assessors were blinded to patient management. This study reports the preliminary results of the interim analysis. RESULTS: The cohort included 47 patients (22 women) with a mean age of 35.7 years. The clinical baselines between these 2 groups were not significantly different. In the DTI/DTT group, the corticospinal tract was affected in 17 patients (73.9%): it was displaced, deformed/partially interrupted, or completely interrupted in 6, 7, and 4 patients, respectively. The surgical approach and brainstem entry point were adjusted in 3 patients (13.0%) based on DTI/DTT data. The surgical morbidity of the DTI/DTT group (7/23, 30.4%) was significantly lower than that of the control group (19/24, 79.2%, p = 0.001). At 12 months, the mean mRS score (1.1, p = 0.034) and percentage of patients with worsened motor deficits (4.3%, p = 0.006) were significantly lower in the DTI/DTT group than in the control group (1.7% and 37.5%). Multivariate logistic regression identified the absence of preoperative DTI/DTT (OR 0.06, 95% CI 0.01-0.73, p = 0.028) and use of the 2-point method (OR 4.15, 95% CI 1.38-12.49, p = 0.011) as independent adverse factors for a worsened motor deficit. The multivariate model found a significant correlation between poor mRS score and both an increased preoperative mRS score (t = 3.559, p = 0.001) and absence of preoperative DTI/DTT (t = -2.747, p = 0.009). CONCLUSIONS: DTI/DTT noninvasively allowed for visualization of the anatomical relationship between vital tracts and pathologies as well as facilitated the brainstem surgical approach and entry-point decision making. The technique was valuable for complex neurosurgical planning to reduce morbidity. Nonetheless, DTI/DTT data should be interpreted cautiously.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized controlled trial; evidence: class I. Clinical trial registration no.: NCT01758211 (ClinicalTrials.gov).

Timing of Surgery and Surgical Strategies in Symptomatic Brainstem Cavernomas: Review of the Literature

Brainstem cavernomas (BSCs) are angiographically occult, benign low flow vascular malformations that pose a significant surgical challenge due to their eloquent location. The present study includes an extensive review of the literature and three illustrative cases of BSC with emphasis on the timing of surgery: surgical approaches, usage of intraoperative monitoring, and complication avoidance. A systematic search was performed using the PubMed database was from January 1, 1999, to June 2018. The relevant articles were reviewed with particular attention to hemorrhage rates, timing of surgery, indications for surgery, surgical approaches, and outcome. Along with this, a retrospective analysis of three cases of symptomatic BSC, who were operated for the same, during the year 2018 in our institute was conducted. All the three patients presented with at least 1 episode of hemorrhage before surgery. Of these, one patient was operated immediately due to altered sensorium whereas the other two were operated after at least 4 weeks of the hemorrhagic episode. The patients who were operated in the subacute phase of bleed were seen to have liquefaction of hematoma, thus providing a good surgical demarcation and thereby reduced surgery-related trauma to the surrounding eloquent structures. Two patients improved neurologically during the immediate postoperative period, whereas one had transient worsening of neurological deficits during the immediate postoperative period in the form of additional cranial nerve palsies which completely improved on follow-up after 2 months. Radical resection is recommended in all patients with symptomatic BSCs. Surgery should be considered after the first or the second episode of hemorrhage as multiple rebleeds can cause exacerbation of deficits and sometimes mortality as well. Considering surgical timing, anywhere between 4 and 6 weeks or the subacute phase of the hemorrhage is considered appropriate. The aims of surgical intervention must be to improve preoperative function, minimize surgical morbidity and to reduce hemorrhagic rates. In spite of the significant surgical morbidity associated with BSCs, appropriate patient selection, meticulous surgical planning with adjuncts such as intraoperative monitoring and neuronavigation will go a long way in avoidance of major postoperative complications.

Pediatric Pontine Cavernous Malformations: The Presigmoid, Posterior Petrosal Approach

BACKGROUND

Brainstem cavernous malformations (cavernomas) in children have a high risk of hemorrhage and neurological deterioration. This risk is magnified if the child has a genetic predisposition for cavernoma formation. The surgical management is challenging and carries a significant risk of morbidity.

OBJECTIVE

To describe the feasibility of a posterior petrosal approach to brainstem cavernomas in a pediatric population.

METHODS

A single institution operative experience with this technique was reviewed; 2 cases were identified and are technically described here with supportive figures and illustrations, as well as a focused literature review.

RESULTS

Two pediatric cases with multiple symptomatic hemorrhages from large expanding pontine cavernomas were identified. Both cavernomas were resected through a presigmoid posterior petrosal approach. While this approach is well described in the adult literature for ventral brainstem lesions, its description for the treatment of pontine cavernomas in the pediatric populations is scarce.

CONCLUSION

This study demonstrates the utility and feasibility of the posterior petrosal approach in two pediatric patients at different points in cranial base development.

Extended middle fossa approach to lateralized pontine cavernomas in children

OBJECTIVE Treatment of hemorrhagic cavernous malformations within the lateral pontine region demands meticulous surgical planning and execution to maximize resection while minimizing morbidity. The authors report a single institution's experience using the extended middle fossa rhomboid approach for the safe resection of hemorrhagic cavernomas involving the lateral pons. METHODS A retrospective chart review was performed to identify and review the surgical outcomes of patients who underwent an extended middle fossa rhomboid approach for the resection of hemorrhagic cavernomas involving the lateral pons during a 10-year period at Rady Children's Hospital of San Diego. Surgical landmarks for this extradural approach were based on the Fukushima dual-fan model, which defines the rhomboid based on the following anatomical structures: 1) the junction of the greater superficial petrosal nerve (GSPN) and mandibular branch of the trigeminal nerve; 2) the lateral edge of the porus trigeminus; 3) the intersection of the petrous ridge and arcuate eminence; and 4) the intersection of the GSPN, geniculate ganglion, and arcuate eminence. The boundaries of maximal bony removal for this approach are the clivus inferiorly below the inferior petrosal sinus; unroofing of the internal auditory canal posteriorly; skeletonizing the geniculate ganglion, GSPN, and internal carotid artery laterally; and drilling under the Gasserian ganglion anteriorly. This extradural petrosectomy allowed for an approach to all lesions from an area posterolateral to the basilar artery near its junction with cranial nerve (CN) VI, superior to the anterior inferior cerebellar artery and lateral to the origin of CN V. Retraction of the mandibular branch of the trigeminal nerve during this approach allowed avoidance of the region involving CN IV and the superior cerebellar artery. RESULTS Eight pediatric patients (4 girls and 4 boys, mean age of 13.2 ± 4.6 years) with hemorrhagic cavernomas involving the lateral pons and extension to the pial surface were treated using the surgical approach described above. Seven cavernomas were completely resected. In the eighth patient, a second peripheral lesion was not resected with the primary lesion. One patient had a transient CN VI palsy, and 2 patients had transient trigeminal hypesthesia/dysesthesia. One patient experienced a CSF leak that was successfully treated by oversewing the wound. CONCLUSIONS The extended middle fossa approach can be used for resection of lateral pontine hemorrhagic cavernomas with minimal morbidity in the pediatric population.

Cavernous malformations of central nervous system in pediatric patients: our single-centered experience in 50 patients and review of literature

PURPOSE

Cavernous malformations (CMs) are rare developmental cerebrovascular malformations of the central nervous system with a childhood prevalence of 0.3 to 0.53%. Our purpose was to assess the clinical features and microsurgical outcome in pediatric central nervous system (CNS) CMs.

MATERIAL AND METHODS

We retrospectively enrolled all the CM patients admitted to our institute from 1 January 2001 to 31 December 2014. Data was analyzed for their clinical features and surgical outcome.

RESULTS

A total of 50 patients with CMs (30 supratentorial, 14 infratentorial, and 6 spinal) with a mean age of 14 years (3-18 years, SD ±4.64) were enrolled into the study. Most of these patients (78%) were male. Size varied from 1.2 to 6 cm. Three patients had multiple CMs. Symptoms of CMs were site specific. Seizure was the most common symptom (63.3%) of CMs at supratentorial location followed by headache (46%) and neurodeficiency (26%), while all brainstem and spinal CMs presented with neurodeficiencies. History of clinically significant acute hemorrhage was present in 19.2% of supratentorial (ST) superficial CMs, 50% of ST deep CMs, 25% of cerebellar CMs, 44.4% of brainstem CMs, and 50% of spinal CMs. Forty-five CMs in 44 patients were surgically excised. Their follow-up ranged from 6 to 162 months (mean 47.2 months, SD ±53). All supratentorial CM patients showed improvement in their symptoms. Patients with preoperative seizure showed good seizure control with Engel scale I in 16 (94.1%) and Engel scale II in 1 (5.9%). In infratentorial (IT) and spinal CM patients, 92.3 and 66.7% had improvement in their neurodeficiencies, respectively. There was no mortality in our series.

CONCLUSION

Microsurgical excision of CNS CM results in excellent neurological outcome in pediatric patients. Early intervention is necessary in spinal CMs for better outcome.

Surgical Treatment of Cavernous Malformations Involving the Midbrain: A Single-Center Case Series of 34 Patients

BACKGROUND

Cavernous malformations (CMs) involving the midbrain are more challenging for surgical treatment than are CMs at other sites because of the surrounding critical structures and deep location. However, specific features and treatment strategies have not been well illustrated.

OBJECTIVE

To evaluate the long-term durability of surgical treatment of midbrain CMs (MBCMs) as well as surgical outcomes and complications.

METHODS

A retrospective study was conducted in 34 patients who underwent microsurgical resection of MBCMs between 1995 and 2015. Demographics, lesion characteristics, surgical approaches, surgical outcomes, and complications were analyzed.

RESULTS

A total of 34 adult patients with a mean age of 38.6 years were assessed. All patients presented with a history of hemorrhage. Lesion locations included the midbrain (n = 27), midbrain and thalamus (n = 2), and pontomesencephalic junction (n = 5). Mean lesion size was 1.7 cm; average clinical follow-up was 5.6 years. Mean modified Rankin Scale (mRS) scores on admission, at discharge, and at last follow-up were 2.0, 2.7, and 1.7, respectively. Postoperatively, 19 patients (55.9%) showed new or worsened neurologic deficits. Multivariate analysis showed that admission mRS score (≥3) was an independent predictor of poor functional outcome (odds ratio, 50.832; 95% confidence interval, 2.967-901.283; P = 0.007). No rehemorrhage or recurrence case was found during the follow-up period.

CONCLUSIONS

Although surgery for MBCMs is associated with significant perioperative morbidity and mortality, most patients show favorable outcomes. Higher preoperative mRS score is an independent predictor of poor functional outcome.

Brainstem and cerebellar cavernous malformations

Cavernous malformations are vascular lesions that occur throughout the central nervous system, most commonly in the supratentorial location, with brainstem and cerebellar cavernous malformations occurring more rarely. Cavernous malformations are associated with developmental venous anomalies that occur sporadically or in familial form. Patients with a cavernous malformation can present with headaches, seizures, sensorimotor disturbances, or focal neurologic deficits based on the anatomic location of the lesion. Patients with infratentorial lesions present more commonly with a focal neurologic deficit. Cavernous malformations are increasingly discovered incidentally due to the increasing use of magnetic resonance imaging. Understanding the natural history of these lesions is essential to their management. Observation and surgical resection are both reasonable options in the treatment of patients with these lesions. The clinical presentation of the patient, the location of the lesion, and the surgical risk assessment all play critical roles in management decision-making.

Giant cavernous malformation in the ventrolateral midbrain with extension into the thalamus: a case report of a paramedian supracerebellar transtentorial approach

Cavernous malformations (CMs) of the midbrain and thalamus are relatively rare and particularly difficult to be resected given their location in eloquent tissues. Here, we report a case of a 14-year-old boy who experienced repeated and progressive right hemiparesis. Image examinations showed a gradually enlarged CM originated in the left ventrolateral midbrain extending to the left thalamus with repeated hemorrhage. By performing a paramedian supracerebellar transtentorial approach, the CM was totally removed, and the patient recovered without any new neurological deficit. The authors' experience suggests that this approach is eminent in treating giant lesions involving the ventrolateral midbrain and thalamus.

Familial Multiple Cavernous Malformation Syndrome: MR Features in This Uncommon but Silent Threat

Cerebral cavernous malformations (CCM) are vascular malformations in the brain and spinal cord. The familial form of cerebral cavernous malformation (FCCM) is uncommon. This autosomal dominant pathology mostly presents with seizures and focal neurological symptoms. Many persons affected by FCCM remain asymptomatic. However, acute hemorrhages may appear over time.

MRI demonstrates multiple focal regions of susceptibility induced signal loss, well seen on gradient-echo sequences (GRE) or even better on susceptibility-weighted imaging (SWI). The presence of a single CCM – especially in young persons – without history of FCCM does not exclude this diagnosis.

Some clinicians also advise an MRI of the spinal cord at the time of diagnosis to serve as a baseline and a control MRI of the brain every one to two years. MRI is certainly indicated in individuals with obvious new neurologic symptoms.

Symptomatic siblings should also undergo an MRI of the brain to determine presence, size, and location of the lesions. Even in asymptomatic siblings, a screening MRI may be considered, as there may be an increased risk of hemorrhage, spontaneous or due to the use of certain medications; the knowledge of the presence and the type of these lesions are important. Surgical removal of a CCM may be justified to prevent a life-threatening hemorrhage. Control MRI may reveal the postoperative outcome.

The Far Lateral Transpontomedullary Sulcus Approach to Pontine Cavernous Malformations: Technical Report and Surgical Results

BACKGROUND:

Pontine cavernous malformations (CMs) located on a peripheral pontine surface or the fourth ventricular floor are resectable lesions, but those deep within the pons away from a pial surface are typically observed. However, the anterior bulge of the pons formed by the brachium pontis creates a unique entry point for access to deep pontine lesions from below, working upward through the pontomedullary sulcus.

OBJECTIVE:

We developed a transpontomedullary sulcus (TPMS) approach to these lesions.

METHODS:

The TPMS approach used the far lateral craniotomy and upper vagoaccessory triangle to define the surgical corridor. The entry point was above the olive, lateral to the pyramidal tracts and cranial nerve (CN) VI, above the preolivary sulcus and CN XII, and medial to CNs VII and VIII and CNs IX through XI.

RESULTS:

Four patients underwent this approach. All presented with hemorrhage and CN VI palsies. All pontine CMs were resected completely. Three patients were improved or unchanged, with good outcomes (modified Rankin Scale score ⩽2) in all patients.

CONCLUSION:

The central pons remains difficult territory to access, and new surgical corridors are needed. The bulging underbelly of the pons allows access to pontine lesions deep to the pial surface from below. The far lateral TPMS approach is a novel and more direct alternative to the retrosigmoid transmiddle cerebellar peduncle approach. Unlike the retrosigmoid approach, the TPMS approach requires minimal parenchymal transgression and uses a brainstem entry point medial to most lower CNs. Favorable results demonstrate the feasibility of resecting pontine CMs that might have been previously deemed unresectable.