Surgical management of brainstem cavernomas

Large Pontine Cavernoma with Hemorrhage: Case Report on Surgical Approach and Recovery

Background/Objectives: Pontine cavernomas are rare and challenging vascular malformations, representing a critical subset of brainstem lesions due to their deep location and proximity to essential neural structures. When hemorrhagic, these lesions can cause rapid neurological deterioration, posing life-threatening risks. Management requires a delicate balance between aggressive intervention and preserving vital functions. This case report presents the successful surgical treatment of a giant hemorrhagic pontine cavernoma, highlighting the integration of advanced imaging, precision surgical techniques, and multidisciplinary care to achieve an exceptional patient outcome. Methods: A 47-year-old female presented with acute neurological deterioration, including severe right-sided hemiparesis, dysphagia, and obnubilation. High-resolution MRI, including susceptibility-weighted imaging, confirmed a giant hemorrhagic pontine cavernoma causing brainstem compression. An urgent left-sided pterional craniotomy with a transsylvian approach was performed to access the lesion. Subtotal resection and hematoma evacuation were carried out to relieve brainstem compression while preserving critical structures. Postoperative recovery and lesion stability were evaluated through clinical assessments and imaging after three months. Results: Postoperatively, the patient exhibited marked neurological recovery, with near-complete resolution of hemiparesis, restored swallowing function, and significant functional improvement. Follow-up imaging confirmed a stable residual lesion, no recurrence of hemorrhage, and a well-preserved ventricular system. The combination of early intervention and tailored surgical strategies resulted in a highly favorable outcome. Conclusions: This case underscores the complexity of managing giant hemorrhagic pontine cavernomas and demonstrates that carefully planned surgical intervention, combined with advanced imaging and patient-focused care, can yield remarkable outcomes. It highlights the critical importance of early diagnosis, meticulous surgical planning, and future innovations in neurovascular surgery to improve outcomes in these rare but high-stakes cases.

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.

Olivary body exposure through far lateral and lower retrosigmoid approaches. Comparative analysis of the exposed surface and angle of attack

OBJECTIVES

Throughout neurosurgical history, the treatment of intrinsic lesions located in the brainstem has been subject of much controversy. The brainstem is the anatomical structure of the central nervous system (CNS) that presents the highest concentration of nuclei and fibers, and its simple manipulation can lead to significant morbidity and mortality. Once one of the safe entry points at the medulla oblongata has been established, we wanted to evaluate the safest approach to the olivary body (the most used safe entry zone on the anterolateral surface of the medulla oblongata). The proposed objective was to evaluate the working channel from the surface of each of the far lateral and retrosigmoid approaches to the olivary body: distances, angles of attack and channel content.

MATERIAL AND METHODS

To complete this work, a total of 10 heads injected with red/blue silicone were used. A total of 40 approaches were made in the 10 heads used (20 retrosigmoid and 20 far lateral). After completing the anatomical study and obtaining the data referring to all the approaches performed, it was decided to expand the sample of this research study by using 30 high-definition magnetic resonance imaging of anonymous patients without cranial or cerebral pathology. The reference points used were the same ones defined in the anatomical study. After defining the working channels in each of the approaches, the working distances, angle of attack, exposed surface, and the number of neurovascular structures present in the central trajectory were analyzed.

RESULTS

The distances to the cranial and medial region of the olivary body were 52.71 mm (SD 3.59) from the retrosigmoid approach and 27.94 mm (SD 3.99) from the far lateral; to the most basal region of the olivary body, the distances were 49.93 (SD 3.72) from the retrosigmoid approach and 18.1 mm (SD 2.5) from the far lateral. The angle of attack to the caudal region was 19.44° (SD 1.3) for the retrosigmoid approach and 50.97° (SD 8.01) for the far lateral approach; the angle of attack to the cranial region was 20.3° (SD 1.22) for the retrosigmoid and 39.9° (SD 5.12) for the far lateral. Regarding neurovascular structures, the probability of finding an arterial structure is higher for the lateral far, whereas a neural structure will be more likely from a retrosigmoid approach.

CONCLUSIONS

As conclusions of this work, we can say that far lateral approach presents more favorable conditions for the microsurgical treatment of intrinsic bulbar and bulbomedullary lesions approached through the caudal half of the olivary body. In those cases of bulbar and pontine-bulbar lesions approached through the cranial half of the olivary body, the retrosigmoid approach can be considered for selected cases.

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.

Surgery for longer duration supranuclear ophthalmoplegia secondary to brain stem cavernoma: A case report and literature review

BACKGROUND

Previous reports revealed that patients with acquired paralytic strabismus caused by central nervous system diseases are primarily affected by the etiology and treatment of the condition. Strabismus correction for these acquired paralytic strabismus should be performed as soon as the primary disease has been stabilized for 6 months in order to archive a favorable surgical outcome.

CASE

We followed an infrequent case of longer-lasting supranuclear ophthalmoplegia secondary to brain stem cavernoma.

OBSERVATION

A 25-year-old Chinese Han female developed aberrant head posture and ipsilateral conjugate gaze palsies 8 years after the first brainstem hemorrhage caused by pontine cavernoma. The patient was diagnosed with supranuclear ophthalmic palsy and brain stem cavernoma after surgery. A resection-recession procedure along with a rectus muscle transposition was performed. The patient's abnormal head position disappeared, with a normal primary position.

CONCLUSION

Resection-recession procedures combined with rectus muscle transposition works very well for longer duration large-angle strabismus caused by brain stem cavernoma.

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.

Radiosurgery effects and adverse effects in symptomatic eloquent brain-located Cavernomas

In this study, the dose schedule efficacy, safety and late adverse effects of stereotactic radiosurgery (SRS) were evaluated for patients with symptomatic cavernomas who were not eligible for surgery and treated with SRS. Between January 2013 and December 2018, 53 patients with cavernomas were treated using SRS with the CyberKnife® system. Patients' diseases were deeply located or were in subcortical functional brain regions. In addition to bleeding, 23 (43.4%) patients had epilepsy, 12 (22.6%) had neurologic symptoms and 16 patients (30.2%) had severe headaches. The median volume was 741 (range, 421-1351) mm3, and the median dose was 15 (range, 14-16) Gy in one fraction. After treatment, six (50%) of 12 patients with neurologic deficits still had deficits. Rebleeding after treatment developed in only two (3.8%) patients. The drug was completely stopped in 14 (60.9%) out of 23 patients who received epilepsy treatment, and the dose of levetiracetam decreased from 2000 mg to 1000 mg in four (17.3%) of nine patients. Radiologically, complete response (CR) was observed in 13 (24.5%) patients, and partial responses (PR) were observed in 32 (60.2%) patients. Clinical response of CR was observed in 30 (56.6%) patients, PR was observed in 16 (30.2%), stable disease (SD) was observed in three (5.7%) and four (7.5%) patients progressed. In conclusion, SRS applied in the appropriate dose schedule may be an effective and reliable method in terms of symptom control and prevention of rebleeding, especially in patients with inoperable cavernomas.

Nomogram for predicting an individual prospective hemorrhage risk in untreated brainstem cavernous malformations

OBJECTIVE

In this study, the authors aimed to create a nomogram for precisely predicting the 5-year prospective hemorrhage risk in brainstem cavernous malformations (BSCMs).

METHODS

Patients with confirmed BSCMs in a single-center prospective observational series from January 2012 to December 2016 were included in the present study for nomogram building and validation. The concordance index (C-index), calibration curves, and decision curve analysis were used to evaluate the predictive accuracy, discriminative ability, and clinical usefulness of the nomogram. Then, a nomogram-based risk stratification model for untreated BSCMs was developed.

RESULTS

In total, 600 patients were included in the study; 417 patients who had been enrolled before July 2015 were divided into the training and validation cohorts, and 183 subsequently enrolled patients were used as the external validation cohort. By applying a backward stepwise procedure in the multivariable Cox model, variables, including prior hemorrhage (HR 1.69), hemorrhage on admission (HR 3.33), lesion size > 1.5 cm (HR 1.84), lesion depth (HR 2.35), crossing the axial midpoint (HR 1.94), and developmental venous anomaly (HR 2.62), were incorporated to develop a nomogram. The Harrell C-index values for a 5-year prospective hemorrhage were 0.752 (95% CI 0.687–0.816), 0.801 (95% CI 0.665–0.936), and 0.758 (95% CI 0.674–0.842) in the training, internal validation, and external validation cohorts, respectively. The nomogram performed well in terms of consistency between prediction and actual observation according to the calibration curve. The patients could be classified into three distinct (low, medium, and high) risk groups using the final score of this nomogram.

CONCLUSIONS

Independent predictors of the 5-year hemorrhage risk in untreated BSCMs were selected to create the first nomogram for predicting individual prospective hemorrhage. The nomogram was able to stratify patients into different risk groups and assist in clinical decision-making.

Cavernous malformations

Cavernous malformations are relatively common intracerebral malformations of which we only became properly aware after the introduction of MRI. They may be sporadic or familial. Familial CMs may be multiple and new lesions appear over time requiring intermittent MR control. Many sporadic CMs have no symptoms. The commonest location is in the supratentorial cerebral parenchyma presenting with epilepsy. The best treatment is microsurgery. A small proportion are in the brainstem and may rebleed and even be lethal. Treatment includes microsurgery and radiosurgery. Microsurgery cures the patient but has substantial problems with complications, deterioration and partial removal. Radiosurgery has taken time to demonstrate that it can over 2 years substantially reduce the risk of rebleeds without the risks of microsurgery. Both methods have a part to play in the treatment.

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 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.

Long-term outcome and quality of life after CNS cavernoma resection: eloquent vs. non-eloquent areas

The aim of this study is to analyze the long-term quality of life after surgery of cavernoma. A monocentric retrospective study was conducted on 69 patients with cavernoma treated microsurgically between 2000 and 2016. The eloquence was adopted from Spetzler-Martin definition. A most recent follow-up was elicited between 2017 and 2019, in which the quality of life (QoL) was evaluated with the Short Form-12 questionnaire (SF12). Forty-one lesions were in eloquent group (EG), 22 in non-eloquent group (NEG), 3 in orbit, and 3 in the spinal cord. Postoperative worsening of the modified Rankin scale (mRS) occurred in 19.5% of cases in EG versus 4.5% in NEG. After a mean follow-up of 6.5 years (SD 4.6), the neurological status was better or unchanged compared to baseline in 85.4% of EG and 100% of NEG. Regarding QoL assessment of 44 patients (EG n = 27, NEG n = 14) attended the last follow-up. Patients after eloquent cavernoma resection reported a non-inferior QoL in most SF12 domains (except for physical role) compared to NEG. However, they reported general health perception inferior to norms, which was affected by the limited physical and emotional roles. At a late follow-up, the surgical morbidity was transient in the NEG and mostly recovered in the EG. The QoL comparison between eloquent and non-eloquent cavernomas created interesting and new data after prolonged follow-up. These results add value for decision-making as well as patient counseling for future encountered cases. Preoperative evaluation of QoL is recommended for future studies to assess QoL dynamics.

Neurological outcomes of untreated brainstem cavernous malformations in a prospective observational cohort and literature review

Background

Haemorrhages of brainstem cavernous malformations (CMs) can lead to neurological deficits, the natural history of which is uncertain. The study aimed to evaluate the neurological outcomes of untreated brainstem CMs and to identify the adverse factors associated with worsened outcomes.

Methods

From 2009 to 2015, 698 patients (321 women) with brainstem CMs were entered into the prospective cohort after excluding patients lost to follow-up (n=43). All patients were registered, clinical data were collected and scheduled follow-up was performed.

Results

After a median follow-up of 60.9 months, prospective haemorrhages occurred in 167 patients (23.9%). The mean modified Rankin Scale scores at enrolment and at censoring time were 1.6 and 1.2. Neurological status was improved, unchanged and worsened in 334 (47.9%), 293 (42.0%) and 71 (10.2%) patients, respectively; 233 (33.4%) recovered to normal levels. Lesions crossing the axial midpoint (relative risk (RR) 2.325, p=0.003) and developmental venous anomaly (DVA) (RR 1.776, p=0.036) were independently significantly related to worsened outcomes. The percentage of worsened outcomes was 5.3% (18 of 337) in low-risk patients (neither DVA nor crossing the axial point) and increased to 26.0% (13 of 50) in high-risk patients (with both DVA and crossing the axial point). The percentage of worsened outcomes significantly increased as the number of prospective haemorrhages increased (from 1.5% (8 of 531, if 0 prospective ictus) to 37.5% (48 of 128, if 1 ictus) and 38.5% (15 of 39, if >1 ictus)).

Conclusions

The neurological outcomes of untreated brainstem CMs were improved/unchanged in majority of patients (89.8%) with a fatality rate of 1.7% in our cohort, which seemed to be favourable. Radiological features significantly predicted worsened outcomes. Our results provide evidence for clinical consultation and individualised treatment. The referral bias of our cohort was underlined.

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.

Optimal access route for pontine cavernous malformation resection with preservation of abducens and facial nerve function

OBJECTIVE

The aim of this study was to analyze the differences between posterolateral and posteromedial approaches to pontine cavernous malformations (PCMs) in order to verify the hypothesis that a posterolateral approach is more favorable with regard to preservation of abducens and facial nerve function.

METHODS

The authors conducted a retrospective analysis of 135 consecutive patients who underwent microsurgical resection of a PCM. The vascular lesions were first classified in a blinded fashion into 4 categories according to the possible or only reasonable surgical access route. In a second step, the lesions were assessed according to which approach was performed and different patient groups and subgroups were determined. In a third step, the modified Rankin Scale score and the rates of permanent postoperative abducens and facial nerve palsies were assessed.

RESULTS

The largest group in this series comprised 77 patients. Their pontine lesion was eligible for resection from either a posterolateral or posteromedial approach, in contrast to the remaining 3 patient groups in which the lesion location already had dictated a specific surgical approach. Fifty-four of these 77 individuals underwent surgery via a posterolateral approach and 23 via a posteromedial approach. When comparing these 2 patient subgroups, there was a statistically significant difference between postoperative rates of permanent abducens (3.7% vs 21.7%) and facial (1.9% vs 21.7%) nerve palsies. In the entire patient population, the abducens and facial nerve deficit rates were 5.9% and 5.2%, respectively, and the modified Rankin Scale score significantly decreased from 1.6 ± 1.1 preoperatively to 1.0 ± 1.1 at follow-up.

CONCLUSIONS

The authors' results suggest favoring a posterolateral over a posteromedial access route to PCMs in patients in whom a lesion is encountered that can be removed via either surgical approach. In the present series, the authors have found such a constellation in 57% of all patients. This retrospective analysis confirms their hypothesis in a large patient cohort. Additionally, the authors demonstrated that 4 types of PCMs can be distinguished by preoperatively evaluating whether only one reasonable or two alternative surgical approaches are available to access a specific lesion. The rates of postoperative sixth and seventh nerve palsies in this series are substantially lower than those in the majority of other published reports.

Risk Factors for Poor Postoperative Outcome and Epileptic Symptoms in Patients Diagnosed with Cerebral Cavernous Malformations

BACKGROUND AND STUDY OBJECTIVE

 Roughly 12 to 47% of individuals with cerebral cavernous malformations (CCM) are asymptomatic, while other people may present with symptoms such as epileptic seizures, neurologic deficits, and intracerebral hemorrhages (IH). The aim of this study was to report our experience of postoperative outcomes of patients diagnosed with CCMs.

PATIENTS AND METHODS

 We present a series of consecutive patients who underwent surgical treatment for a diagnosed CCM between January 2003 and March 2014. Data were retrospectively analyzed with respect to preoperative visits, operating reports, patient admission charts, and postoperative follow-up visits. The Engel scale was used to evaluate the outcome of patients with epileptic seizures.

RESULTS

 A total of 91 patients were included with a mean age of 38.8 ± 15 years (range: 2-72 years). Prior to surgery, 57 of these patients had epileptic seizures, while 25 patients recorded at least one episode of IH with a latency time of 6.7 ± 8.5 years (range: 3-240 months) in between hemorrhages. A CCM located within the brainstem was significantly associated with IH prior to surgery (p = 0.000). If the CCM was adjacent to an eloquent brain area, the postoperative outcome in terms of seizure control was significantly worse (p = 0.033). In addition, a trend for worsened outcomes according to the Engel scale was observed in patients with more than one seizure prior to surgery (p = 0.055).

CONCLUSION

 Proximity of CCMs to eloquent brain areas is a risk factor for poor postoperative outcome with respect to a lower rate of medication reduction as well as a lower rate of epileptic seizure omission. This underlines the importance of patient-specific therapeutic approaches.

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.

Emergency surgery for brainstem cavernoma haemorrhage with severe neurological presentation. Is it indicated and worthwhile?

Background: Brainstem Cavernoma (BSCM) haemorrhage is a complex condition, especially when patients present rapid neurological deterioration. Traditionally, these patients were initially treated by non-interventional means. Surgery was generally reserved for cases who presented a 'benign' evolution in a subacute/delayed fashion. Timing of surgery remains controversial. Since rebleeding is frequent and carries a high mortality, many of these patients do not tolerate this approach. Urgent/emergent surgery may be indicated and lifesaving.Methods: A single center experience is reported in which an aggressive approach was used with urgent/emergency surgery carried out on patients with BSCM haemorrhage and rapid neurological deterioration, ventilatory impairment and/or coma. A review of 5 consecutive cases where urgent/emergent surgery was performed is presented. The pre-operative status, pre- and post-operative examinations, surgical approach and neurological residual deficits/outcomes are reported.Results: Four females and one male with ages ranging from 36 to 66 years with rapid neurological deterioration, ventilatory impairment and/or coma were operated between 2011 and 2018. Favourable outcomes were observed with a modified Rankin Scale varying from 1 to 4. Cranial nerve deficits as well as motor and sensitive deficits were observed but all the patients recovered cognitive integrity.Conclusions: Our small series reveals an acceptable outcome with ultra-early surgery. This approach appears to be a valid option when there is rapid neurological deterioration, respiratory impairment and/or early onset coma. However, further studies are required to elucidate the optimal strategy.

Surgical managements and patient outcomes after severe hemorrhagic events from brainstem cavernous malformations

To evaluate the surgical outcomes and predictors and the impact of surgical timing of patients who suffered a severe hemorrhagic event from brainstem cavernous malformations (CMs). The clinical data of all patients who underwent surgical treatment after a severe bleeding ictus from brainstem CMs between 2011 and 2017 were retrospectively reviewed. The study population consisted of 61 surgical patients (40, 65.6% female). Surgical times of < 3 weeks, ≥ 3-8 weeks, and > 8 weeks since the last bleeding ictus were observed in 23 (37.7%), 24 (39.3%), and 14 (23.0%) patients, respectively. The mean modified Rankin scale (mRS) score evaluated on admission was 4.2. With a mean follow-up of 39.8 months, 39 patients (63.9%) had a favorable outcome (mRS ≤ 2), and the mean mRS score was 2.3. The logistic regression analysis identified age, having disrupted consciousness and/or respiration, and time to surgery from last hemorrhage as significant predictors of long-term outcome. In particular, patients with surgery performed during the acute period (< 3 weeks, P = 0.06) or chronic period (> 8 weeks, P = 0.01) tended to have poor outcomes when compared with those with surgery during the subacute period (≥ 3-8 weeks). Favorable neurological outcomes can be achieved in patients who were surgically treated after a severe hemorrhagic ictus from brainstem CMs, and operation during subacute hemorrhage (≥ 3-8 weeks) could benefit these patients.

Radiosurgery for Symptomatic Cavernous Malformation in the Brainstem: Two Difficult Cases with Large and Multiple Lesions

It is well known that cavernous malformations become much more hemorrhagic after the initial hemorrhage and that brainstem lesions are more dangerous than the lesions in the supratentorial location. It is very difficult to handle symptomatic cavernous malformations associated with repetitive hemorrhages in the brainstem. Patients may be suffering from brainstem syndromes such as hemiparesis, hemisensory disturbance, ataxia, and disturbed ocular movement. We have encountered two such difficult cases, one is very large and the other is multiple and familiar, accompanying repetitive brainstem hemorrhages. Since microsurgery seems to be very difficult and hazardous, these two cases were treated with radiosurgery after several hemorrhages.

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 Treatment of Brainstem Cavernous Malformation with Concomitant Developmental Venous Anomaly

Surgical resection of brainstem cavernous malformations (BCMs) is a high-risk procedure and can be challenging to the neurosurgeon. Lateral surgical routes are becoming increasingly used to approach ventrolaterally brainstem cavernoma. Surgical approach decision depends on the location of the cavernoma in the brainstem and a possible association with brainstem developmental venous anomalies (DVAs). DVA can affect the formation and clinical course of cavernous malformation (CM). CMs related to DVAs tend to have more aggressive behavior than isolated CM. In cases of DVAs associated with hemorrhage, CMs are most often the site of bleeding rather than DVAs themselves. In this case report, we present a 24-year-old woman with a pontomedullary CM and associated dorsally located DVA. BCM was operated through a far lateral suboccipital craniotomy. Brainstem entry point was at inferior olive with extension to the pontomedullary sulcus. This approach should be preferred as a safe surgical exposure to the central and paramedian pontomedullary cavernoma, especially in the cases with associated intraparenchymal brainstem DVA. Such surgical exposure allows preservation of the concomitant brainstem DVA.

Surgical Approaches for Symptomatic Cerebral Cavernous Malformations of the Thalamus and Brainstem

Objective

Surgical resection of thalamic and brainstem cerebral cavernous malformations (CCMs) is associated with significant operative morbidity, but it may be outweighed, in some cases, by the neurological damage from recurrent hemorrhage in these eloquent areas. The goals of this retrospective cohort study are to describe the technical nuances of surgical approaches and determine the postoperative outcomes for CCMs of the thalamus and brainstem.

Materials and Methods

We reviewed an institutional database of patients harboring thalamic or brainstem CCMs, who underwent surgical resection from 2010 to 2014. The baseline and follow-up neuroimaging and clinical findings of each patient and the operative details of each case were evaluated.

Results

A total of eight patients, including two with thalamic and six with brainstem CCMs, were included in the study cohort. All patients had progressive neurological deterioration from recurrent CCM hemorrhage, and the median modified Rankin Scale (mRS) at presentation was 3. The median CCM maximum diameter and volume were 1.7 cm and 1.8 cm³, respectively. The thalamic CCMs were resected using the anterior transcallosal transchoroidal and supracerebellar infratentorial approaches each in one case (13%). The brainstem CCMs were resected using the retrosigmoid and suboccipital trans-cerebellomedullary fissure approaches each in three cases (38%). After a median follow-up of 11.5 months, all patients were neurologically stable or improved, with a median mRS of 2. The rate of functional independence (mRS 0-2) was 63%.

Conclusion

Microneurosurgical techniques and approaches can be safely and effectively employed for the management of thalamic and brainstem CCMs in appropriately selected patients.

Genome-Wide Sequencing Reveals MicroRNAs Downregulated in Cerebral Cavernous Malformations

Cerebral cavernous malformations (CCM) are vascular lesions associated with loss-of-function mutations in one of the three genes encoding KRIT1 (CCM1), CCM2, and PDCD10. Recent understanding of the molecular mechanisms that lead to CCM development is limited. The role of microRNAs (miRNAs) has been demonstrated in vascular pathologies resulting in loss of tight junction proteins, increased vascular permeability and endothelial cell dysfunction. Since the relevance of miRNAs in CCM pathophysiology has not been elucidated, the primary aim of the study was to identify the miRNA-mRNA expression network associated with CCM. Using small RNA sequencing, we identified a total of 764 matured miRNAs expressed in CCM patients compared to the healthy brains. The expression of the selected miRNAs was validated by qRT-PCR, and the results were found to be consistent with the sequencing data. Upon application of additional statistical stringency, five miRNAs (let-7b-5p, miR-361-5p, miR-370-3p, miR-181a-2-3p, and miR-95-3p) were prioritized to be top CCM-relevant miRNAs. Further in silico analyses revealed that the prioritized miRNAs have a direct functional relation with mRNAs, such as MIB1, HIF1A, PDCD10, TJP1, OCLN, HES1, MAPK1, VEGFA, EGFL7, NF1, and ENG, which are previously characterized as key regulators of CCM pathology. To date, this is the first study to investigate the role of miRNAs in CCM pathology. By employing cutting edge molecular and in silico analyses on clinical samples, the current study reports global miRNA expression changes in CCM patients and provides a rich source of data set to understand detailed molecular machinery involved in CCM pathophysiology.

Gamma Knife Radiosurgery of Brainstem Cavernous Malformations

BACKGROUND/AIMS

Our study aimed to evaluate the efficiency and morbidity of Gamma Knife radiosurgery (GKS) in the treatment of hemorrhagic brainstem cavernous malformations (CMs).

METHODS

We included in this study all patients who underwent GKS for the treatment of a hemorrhagic brainstem CM(s) in our institution between January 2007 and December 2012. The GKS was privileged when the surgical procedure was evaluated as very risky. The mean dose of radiation was 14.8 Gy, and the mean target volume was 0.282 cm3. All patients participated in a scheduled clinical follow-up. The posttreatment MRI was performed after 6 months and after 1 year, and then all patients had an annual MRI follow-up.

RESULTS

There were 19 patients with a mean age of 36.7 years. The mean follow-up period was 51.2 months. The annual hemorrhage rate (AHR) was 27.31% before GKS, 2.46% during the first 2 years following the GKS, and 2.46% after the first 2 years following the GKS. The decrease in AHR after GKS was significant (p < 0.001).

CONCLUSION

GKS should be suggested when the surgical procedure harbors a high risk of neurological morbidity in patients with brainstem CM. Compared to prior literature results, a lower dose than applied in this study could be discussed.

Surgical management of symptomatic brain stem cavernoma in a developing country: technical difficulties and outcome

Brain stem cavernomas (BSCs) are angiographically occult vascular malformations in an intricate location. Surgical excision of symptomatic BSCs represents a neurosurgical challenge especially in developing countries. We reviewed the clinical data and surgical outcome of 24 consecutive cases surgically treated for brain stem cavernoma at the Neurosurgery Department, Alexandria University, between 2006 and 2014. All patients were followed up for at least 12 months after surgery and the mean follow-up period was 45 months. All patients suffered from at least two clinically significant hemorrhagic episodes before surgery. There were 10 males and 14 females. The mean age was 34 years (range 12 to 58 years). Fourteen cases had pontine cavernomas, 7 cases had midbrain cavernomas, and in 3 cases, the lesion was found in the medulla oblongata. The most commonly used approach in this series was the midline suboccipital approach with or without telovelar exposure (9 cases). There was a single postoperative mortality in this series due to pneumonia. Fourteen cases (58.3 %) showed initial worsening of their preoperative neurological status, most of which was transient and only three patients had permanent new deficits and one case had a permanent worsening of her preoperatively existing hemiparesis. There was neither immediate nor long-term rebleeding in any of our cases. In spite of the significant associated risks, surgery for BSCs in properly selected patients can have favorable outcomes in most cases. Surgery markedly improves the risk of rebleeding and should be considered in patients with accessible lesions.

Use of Actuator-Driven Pulsed Water Jet in Brain and Spinal Cord Cavernous Malformations Resection

BACKGROUND

A piezo actuator-driven pulsed water jet (ADPJ) system is a novel surgical instrument that enables dissection of tissue without thermal damage. It can potentially resect intra-axial lesions while preserving neurological function.

OBJECTIVE

To report our first experience of applying an ADPJ system to brain and spinal cord cavernous malformations.

METHODS

Four patients (2 women and 2 men, mean age 44.5 years) with brain (n = 3) and spinal cord (n = 1) cavernous malformations were enrolled in the study. All surgeries were performed with the aid of the ADPJ system. Postoperative neurological function and radiological findings were evaluated.

RESULTS

The ADPJ system was useful in dissecting boundaries between the lesion and surrounding brain/spinal cord tissues. The pulsed water jet provided a clear surgical view and helped surgeons follow the margins. Water jet dissection peeled off the brain and spinal cord tissues from the lesion wall. Surrounding gliotic tissue was preserved. As a consequence, the cavernous malformations were successfully removed. Postoperative magnetic resonance imaging confirmed total removal of lesions in all cases. Preoperative neurological symptoms completely resolved in 2 patients. The others experienced partial recovery. No patients developed new postoperative neurological deficits; facial palsy temporarily worsened in 1 patient who underwent a suprafacial colliculus approach for the brainstem lesion.

CONCLUSION

The ADPJ provided a clear surgical field and enabled surgeons to dissect boundaries between lesions and surrounding brain and spinal cord gliotic tissue. The ADPJ system is a feasible option for cavernous malformation surgery, enabling successful tumor removal and preservation of neurological function.

Endoscopic Endonasal Transclival Resection of a Brainstem Cavernoma: A Detailed Account of Our Technique and Comparison with the Literature

OBJECTIVE

To report a technique of endoscopic transclival resection of a hemorrhagic brainstem cavernous malformation manifesting in the ventral pons.

METHODS

A 29-year-old woman presented with numbness and tingling of the right arm and leg and loss of fine motor control. Magnetic resonance imaging revealed a cavernoma in the ventromedial brainstem on the ventral surface. A purely endoscopic, endonasal, transclival approach was used to resect this cavernoma. Computed tomography/magnetic resonance imaging merged navigation (StealthStation, Medtronic) was used.

RESULTS

The patient had no neurologic deficits postoperatively. The motor control loss and tingling disappeared. She did not experience any complications. Cerebrospinal fluid leakage appeared to result from using the very small opening of the skull base and dura mater and was the reason for the use of a lumbar drain for several days. At the 6-week follow-up examination, the patient was in excellent condition with no neurologic deficits and had returned to her full-time job.

CONCLUSIONS

Successful endoscopic, endonasal, transclival resection of a brainstem cavernous malformation was described. This patient experienced improvement in neurologic symptoms after surgery without morbidity. Technologic advances in endoscopic skull base approaches provide access to lesions of the brainstem that previously required more invasive approaches. The endonasal transclival approach provides the most direct route to ventral pontine lesions. Early intervention in brainstem cavernous malformation is indicated and should be performed with an individualized approach taking into consideration the possible complications.

Anatomy and approaches along the cerebellar-brainstem fissures

OBJECT Fissure dissection is routinely used in the supratentorial region to access deeply situated pathology while minimizing division of neural tissue. Use of fissure dissection is also practical in the posterior fossa. In this study, the microsurgical anatomy of the 3 cerebellar-brainstem fissures (cerebellomesencephalic, cerebellopontine, and cerebellomedullary) and the various procedures exposing these fissures in brainstem surgery were examined. METHODS Seven cadaveric heads were examined with a microsurgical technique and 3 with fiber dissection to clarify the anatomy of the cerebellar-brainstem and adjacent cerebellar fissures, in which the major vessels and neural structures are located. Several approaches directed along the cerebellar surfaces and fissures, including the supracerebellar infratentorial, occipital transtentorial, retrosigmoid, and midline suboccipital approaches, were examined. The 3 heads examined using fiber dissection defined the anatomy of the cerebellar peduncles coursing in the depths of these fissures. RESULTS Dissections directed along the cerebellar-brainstem and cerebellar fissures provided access to the posterior and posterolateral midbrain and upper pons, lateral pons, floor and lateral wall of the fourth ventricle, and dorsal and lateral medulla. CONCLUSIONS Opening the cerebellar-brainstem and adjacent cerebellar fissures provided access to the brainstem surface hidden by the cerebellum, while minimizing division of neural tissue. Most of the major cerebellar arteries, veins, and vital neural structures are located in or near these fissures and can be accessed through them.

Disorders of the lower cranial nerves

Lesions of the lower cranial nerves (LCN) are due to numerous causes, which need to be differentiated to optimize management and outcome. This review aims at summarizing and discussing diseases affecting LCN. Review of publications dealing with disorders of the LCN in humans. Affection of multiple LCN is much more frequent than the affection of a single LCN. LCN may be affected solely or together with more proximal cranial nerves, with central nervous system disease, or with nonneurological disorders. LCN lesions have to be suspected if there are typical symptoms or signs attributable to a LCN. Causes of LCN lesions can be classified as genetic, vascular, traumatic, iatrogenic, infectious, immunologic, metabolic, nutritional, degenerative, or neoplastic. Treatment of LCN lesions depends on the underlying cause. An effective treatment is available in the majority of the cases, but a prerequisite for complete recovery is the prompt and correct diagnosis. LCN lesions need to be considered in case of disturbed speech, swallowing, coughing, deglutition, sensory functions, taste, or autonomic functions, neuralgic pain, dysphagia, head, pharyngeal, or neck pain, cardiac or gastrointestinal compromise, or weakness of the trapezius, sternocleidomastoid, or the tongue muscles. To correctly assess manifestations of LCN lesions, precise knowledge of the anatomy and physiology of the area is required.

The lateral infratrigeminal transpontine window to deep pontine lesions

OBJECT

Surgery of brainstem lesions is increasingly performed despite the fact that surgical indications and techniques continue to be debated. The deep pons, in particular, continues to be a critical area in which the specific risks related to different surgical strategies continue to be examined. With the intention of bringing new knowledge into this important arena, the authors systematically examined the results of brainstem surgeries that have been performed through the lateral infratrigeminal transpontine window.

METHODS

Between 1990 and 2013, 29 consecutive patients underwent surgery through this window for either biopsy sampling or for removal of a deep pontine lesion. All of this work was performed at the Department of Neurosurgery of the Istituto Nazionale Neurologico "Carlo Besta", in Milan, Italy. A retrospective analysis of the findings was conducted with the intention of bringing further clarity to this important surgical strategy.

RESULTS

The lateral infratrigeminal transpontine window was exposed through 4 different approaches: 1) classic retrosigmoid (15 cases), 2) minimally invasive keyhole retrosigmoid (10 cases), 3) translabyrinthine (1 case), and 4) combined petrosal (3 cases). No deaths occurred during the entire clinical study. The surgical complications that were observed included hydrocephalus (2 cases) and CSF leakage (1 case). In 6 (20.7%) of 29 patients the authors encountered new neurological deficits during the immediate postoperative period. All 6 of these patients had undergone lesion removal. In only 2 of these 6 patients were permanent sequelae observed at 3 months follow-up. These findings show that 93% of the patients studied did not report any permanent worsening of their neurological condition after this surgical intervention.

CONCLUSIONS

This retrospective study supports the idea that the lateral infratrigeminal transpontine window is both a low-risk and safe corridor for either biopsy sampling or for removal of deep pontine lesions.

Radiosurgery for symptomatic cavernous malformations: A multi-institutional retrospective study in Japan

BACKGROUND

A group study for symptomatic cavernous malformation (CM) treated with gamma knife (GK) surgery was performed.

METHODS

A total of 298 cases collected from 23 GK centers across Japan were included. Hemorrhage was the most common manifestation, followed by seizures and neurological deficits. Most of the lesions were located in the brainstem and basal ganglia, followed by the cerebral or cerebellar hemispheres. The CMs, which had a mean diameter of 14.8 mm, were treated using GK surgery with a mean marginal dose of 14.6 Gy.

RESULTS

In terms of hemorrhage-free survival (HFS), a marked dissociation was confirmed between the hemorrhage and seizure groups, while no obvious difference was noted between sexes. Superficial CMs located in cerebellum or lobar regions responded to the treatment better than deeply located CMs in the basal ganglia or brainstem. No significant difference of dose-dependent response was seen for three different ranges of marginal dose: Less than 15 Gy, between 15 and 20 Gy, and more than 20 Gy. Complications were more frequent after a marginal dose of over 15 Gy and in patients with lesions more than 15 mm in diameter. The rates of annual hemorrhage were estimated to be 7.4% during the first 2 years after radiosurgery and 2.8% thereafter. The overall hemorrhage rate after radiosurgery was 4.4%/year/patient.

CONCLUSION

The risk of hemorrhage is considerably reduced after GK treatment. The HFS as well as annual hemorrhage rate after GK treatment was apparently superior to that after conservative treatment for symptomatic CMs. To optimize the success of GK treatment, it is important to reduce the incidence of complications.

A systematic review and meta-analysis of surgeries performed for treating deep-seated cerebral cavernous malformations

OBJECTIVE

The clinical benefit of surgery for treatment of deep-seated cerebral cavernous malformations (CCMs) is still a matter of debate. Although the surgical removal of CCMs is widely accepted, the benefits of reducing the rate of haemorrhage must be balanced against the risk of peri-operative morbidity. Here, we provide a systematic review and meta-analysis of the clinical benefits of surgery for treating deeply localised CCMs.

METHODS

A comprehensive search of PubMed and Embase was conducted to identify relevant studies. The rate and a 95% confidence interval (CI) were used to measure the risk of haemorrhage and adverse outcomes.

RESULTS

A total of 34 cohort studies reporting surgeries on CCMs were included in our analysis. Overall, the average post-surgical haemorrhage rate was 1.0% (95% CI: 0.7-1.4%). Nine per cent (95% CI: 6.9-11.3%) of the patients developed adverse events at follow-up following the surgical resection of deep-seated CCMs. The percentage of transient neural defects following surgical resection was 34.6% (95% CI: 29.4-39.9%). The proportions of transient focal neurological defect before and after the year 2006 were 44.9% (95% CI: 34.1-55.8%) and 30.3% (95% CI: 25.1-35.9%), respectively.

CONCLUSIONS

Our meta-analysis demonstrates post-surgical haemorrhage rate and complications related to surgeries on deep-seated CCMs. The post-surgical haemorrhage rate was low with a relatively high rate of post-surgical complications.

Anterior petrosal approach for brainstem cavernoma

Brainstem cavernomas (BC) comprise about 5-18% of intracranial vascular malformations. The annual hemorrhage rate varies depending on the study design ranging from as low as 0.25% per patient-year in a retrospective study[2] to 1.6-3.1% per patient-year in prospective studies.[45] The annual event rate is significantly higher in deep (brainstem, diencephalon) and infratentorial cavernomas when compared to their counterparts in other locations.[5] The management of BC can be conservative or surgical depending upon the mode of clinical presentation. Surgical excision of a BC is a challenge because of critical anatomy. We present a case of BC, which was totally excised with anterior petrosal approach. Anterior petrosal approach has been used for excision of BC in only 17 cases until now.[6] The use of preoperative diffusion tensor imaging, tractography, intra-operative navigation, and cranial nerve monitoring will help in reducing the morbidity.

Unusual Presentation of Cerebral Cavernous Malformation

Cerebral cavernous malformations (CMs) are vascular malformations of the central nervous system, which can be detected in the absence of any clinical symptoms. Nodules and cysts with mixed signal intensity and a peripheral hemosiderin rim are considered brain magnetic resonance imaging (MRI) findings typical of CMs. A 48-year-old man was admitted to our hospital because of abnormal MRI findings without significant neurological symptoms. A cyst with an internal fluid-fluid level was found in the left basal ganglia on the initial brain MRI. We decided to observe the natural course of the asymptomatic lesion with serial MRI follow-up. On MRI at the 5-month follow-up, the cystic mass was enlarged and showed findings consistent with those of cystic CM. Surgical resection was performed and the pathological diagnosis was CM. Our experience suggests that the initial presentation of a CM can be a pure cyst and neurosurgeons should consider the likelihood of CMs in cases of cystic cerebral lesions with intracystic hemorrhage.

Treatment of cerebral cavernous malformations: a systematic review and meta-regression analysis

OBJECTIVE

The reported effects of treating cerebral cavernous malformations (CCMs) by neurosurgical excision or stereotactic radiosurgery are imprecise and vary between studies.

METHODS

We searched Ovid Medline, EMBASE and The Cochrane Library for peer-reviewed publications of cohort studies describing outcomes of treating 20 or more patients with CCM with at least 80% completeness of follow-up. Two reviewers extracted data to quantify the incidence of a composite outcome (death, non-fatal intracranial haemorrhage, or new/worse persistent focal neurological deficit) after CCM treatment. We explored associations between summary measures of study characteristics and outcome using Poisson meta-regression analyses.

RESULTS

We included 63 cohorts, involving 3424 patients. The incidence of the composite outcome was 6.6 (95% CI 5.7 to 7.5) per 100 person-years after neurosurgical excision (median follow-up 3.3 years) and 5.4 (95% CI 4.5 to 6.4) after stereotactic radiosurgery (median follow-up 4.1 years). After neurosurgical excision the incidence of the composite outcome increased with every per cent point increase in patients with brainstem CCM (rate ratio (RR) 1.03, 95% CI 1.01 to 1.05), and decreased with each more recent study midyear (RR 0.91, 95% CI 0.85 to 0.98) and each per cent point increase in patients presenting with haemorrhage (RR 0.98, 95% CI 0.96 to 1.00). We did not find significant associations in studies of stereotactic radiosurgery.

CONCLUSIONS

The reported risks of CCM treatment (and the lower risks of neurosurgical excision over time, from recently bled CCMs, and for CCMs outside the brainstem) compare favourably with the risks of recurrent haemorrhage from CCM. Long-term effects, especially important for stereotactic radiosurgery, are unknown.

Surgical management of pediatric brainstem cavernous malformations

OBJECT

The goal of this study was to evaluate surgical outcomes of pediatric brainstem cavernous malformations (CMs) and identify the risk factors associated with postoperative full recovery and rebleeding.

METHODS

The clinical charts and radiographs from a series of 52 pediatric patients (37 male and 15 female; mean age 12.2 years; range 1-17 years) who underwent surgery for brainstem CMs between 1996 and 2011 were reviewed. Follow-up evaluation measures were obtained retrospectively. Neurological function was evaluated using the modified Rankin Scale (mRS) score.

RESULTS

The lesion locations among the 52 patients included the midbrain (n = 7, 13.5%), pons (n = 38, 73.1%), and medulla (n = 7, 13.5%). The mean duration of symptoms was 18.5 months, and the preoperative annual hemorrhage and rebleeding rates were 12.3% and 32.5% per patient-year, respectively. The mean lesion size was 2.1 cm. Gross-total resection without surgery-related death was achieved in 49 patients (94.2%). Immediate postoperative reduced neurological function was observed in 17 patients (32.7%). Surgical morbidities developed in 25 patients (48.1%) and remained in 11 patients (21.2%) after 7.9 years of follow-up. The mean mRS scores at admission, discharge after surgery, 3 and 6 months postsurgery, and recent evaluation were 2.0, 2.3, 2.0, 1.5, and 1.0, respectively. The postoperative mRS scores at 6 months (p < 0.001) and on recent evaluation (p < 0.001) were significantly lower than those at admission. Postoperative rebleeding occurred in 2 patients, and the postoperative annual rebleeding rate was 0.5% per patient-year. By the most recent evaluation, 10 patients (19.2%) had achieved full recovery and all patients were either improved (n = 32, 61.5%) or unchanged (n = 20, 38.5%). The adverse predictors for full recovery included age ≥ 12 years (HR 0.230, p = 0.021), ≥ 2 preoperative hemorrhages (HR 0.124, p = 0.048), and poor preoperative status (HR 0.197, p = 0.040). An HR < 1 predicted poor complete recoveries. The single risk factor predicting postoperative rebleeding was incomplete resection (χ2 = 4.340, p = 0.037).

CONCLUSIONS

Fair outcomes for pediatric brainstem CMs could be obtained through surgery, but only a few patients achieved full recovery. Thus, to minimize surgical morbidity, surgical planning must be tailored to individual patients in all cases in which an operation is warranted. Complete resection must be attempted to reduce the risk of postoperative rebleeding. The predictors associated with complete postoperative recovery were referential for determining treatment.

Cavernous malformation of brainstem, thalamus, and basal ganglia: a series of 176 patients

BACKGROUND

Cavernous malformations (CMs) in deep locations account for 9% to 35% of brain malformations and are surgically challenging.

OBJECTIVE

To study the clinical features and outcomes following surgery for deep CMs and the complication of hypertrophic olivary degeneration (HOD).

METHODS

Clinical records, radiological findings, operative details, and complications of 176 patients with deep CMs were reviewed retrospectively.

RESULTS

Of 176 patients with 179 CMs, 136 CMs were in the brainstem, 27 in the basal ganglia, and 16 in the thalamus. Cranial nerve deficits (51.1%), hemiparesis (40.9%), numbness (34.7%), and cerebellar symptoms (38.6%) presented most commonly. Hemorrhage presented in 172 patients (70 single, 102 multiple). The annual retrospective hemorrhage rate was 5.1% (assuming CMs are congenital with uniform hemorrhage risk throughout life); the rebleed rate was 31.5%/patient per year. Surgical approach depended on the proximity of the CM to the pial or ependymal surface. Postoperatively, 121 patients (68.8%) had no new neurological deficits. Follow-up occurred in 170 patients. Delayed postoperative HOD developed in 9/134 (6.7%) patients with brainstem CMs. HOD occurred predominantly following surgery for pontine CMs (9/10 patients). Three patients with HOD had palatal myoclonus, nystagmus, and oscillopsia, whereas 1 patient each had limb tremor and hemiballismus. At follow-up, 105 patients (61.8%) improved, 44 (25.9%) were unchanged, and 19 (11.2%) worsened neurologically. Good preoperative modified Rankin Score (98.2% vs 54.5%, P = .001) and single hemorrhage (89% vs 77.3%, P < .05) were predictive of good long-term outcome.

CONCLUSION

Symptomatic deep CMs can be resected with acceptable morbidity and outcomes. Good preoperative modified Rankin Score and single hemorrhage are predictors of good long-term outcome.

Flexible Omnidirectional Carbon Dioxide Laser as an Effective Tool for Resection of Brainstem, Supratentorial, and Intramedullary Cavernous Malformations

BACKGROUND:

Lasers have a long history in neurosurgery, yet bulky designs and difficult ergonomics limit their use. With its ease of manipulation and multiple applications, the OmniGuide CO2 laser has reintroduced laser technology to the microsurgical resection of brain and spine lesions. This laser, delivered through a hollow-core fiber lined with a unidirectional mirror, minimizes energy loss and allows precise targeting.

OBJECTIVE:

To analyze resections performed by the senior author from April 2009 to March 2013 of 58 cavernous malformations (CMs) in the brain and spine with the use of the OmniGuide CO2 laser, to reflect on lessons learned from laser use in eloquent areas, and to share data on comparisons of laser power calibration and histopathology.

METHODS:

Data were collected from electronic medical records, radiology reports, operative room records, OmniGuide CO2 laser case logs, and pathology records.

RESULTS:

Of 58 CMs, approximately 50% were in the brainstem (30) and the rest were in supratentorial (26) and intramedullary spinal locations (2). Fifty-seven, ranging from 5 to 45 mm, were resected, with a subtotal resection in 1. Laser power ranged from 2 to 10 W. Pathology specimens showed minimal thermal damage compared with traditionally resected specimens with bipolar coagulation.

CONCLUSION:

The OmniGuide CO2 laser is safe and has excellent precision for the resection of supratentorial, brainstem, and spinal intramedullary CMs. No laser-associated complications occurred, and very low energy was used to dissect malformations from their surrounding hemosiderin-stained parenchymas. The authors recommend its use for deep-seated and critically located CMs, along with traditional tools.