Cavernous malformations of the brainstem: experience with 100 patients

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.

Cerebellar cavernous malformations with and without associated developmental venous anomalies

BACKGROUND

The clinical profiles of cerebellar cavernous malformations (CCMs) with and without associated developmental venous anomalies (DVAs) are not well known. The aims of this study were to analyze the clinical and radiological characteristics of CCMs and to assess the various therapeutic strategies.

METHODS

A consecutive series of 41 patients with identified CCMs were retrospectively reviewed. Of these, 11 patients (26.8%) were found to have associated DVAs. We compared the clinical profile of the two groups of patients (CCMs with and without DVAs). The CCMs with DVAs cases underwent radical resection of the CCMs, and the distal radicles of the DVAs that directly drain from the CCMs were coagulated and dissected at the length of the CCMs.

RESULTS

There were no statistically significant differences between the two groups with regard to age, sex, location and size of lesions, multiplicity, and surgical prognosis. The patients with CCMs with DVAs did not experience any brain swelling or hemorrhagic tendency intraoperatively. The postoperative course was uneventful for all of the 36 surgical patients with the exception of two of the patients with CCMs with associated DVAs, who suffered from serious cerebellar edema, and one of these two patients underwent an emergency suboccipital decompression craniotomy. With the exception of three patients who were lost to follow-up (mean, 22.3 months), all of the CCMs patients exhibited good long-term prognosis (modified Rankin scale values of 0-2) and no reoccurrence.

CONCLUSIONS

It is not rare that associated DVAs occur in CCMs. The total removal of the CCM combined with the coagulation and dissection of the distal radicles of DVA at the length of the associated CCM may result in good long-term prognosis in patients.

Symptomatic cavernous malformations of the brainstem: functional outcome after microsurgical resection

Brainstem cavernous malformations are associated with a considerable risk of hemorrhage and subsequent morbidity. This study provides a detailed work-up of clinical and radiological outcome as well as identification of prognostic factors in patients who had suffered from symptomatic hemorrhages. Patients who had undergone surgery of symptomatic BSCMs were evaluated pre- and postoperatively both neurologically and neuroradiologically supplemented by telephone interviews. Additionally, patients were scored according to the Scandinavian Stroke Scale. Multiple uni- and multivariate analyses of possible clinical and radiological prognostic factors were conducted. The study population comprised 35 patients. Mean age at operation was 39.3 ± 13.0 years with microsurgical resection of a total of 37 different BSCMs between 2002 and 2011. Median clinical follow-up was 44.0 months (range 8-116 months). Postoperative MRI showed eventually complete resection of all BSCMs. Postoperative overall outcome revealed complete resolution of neurological symptoms for 5/35 patients, 14/35 improved and 9/35 remained unchanged. 7/35 suffered from a postoperative new and permanent neurological deficit, mostly affecting the facial nerve or hemipareses with mild impairment. Pre- and postoperative Scandinavian Stroke Scale scores were 11.0 ± 2.4 and 11.4 ± 2.2 (p = 0.55). None of the analyzed factors were found to significantly correlate with patients' clinical outcome. Complete resection of brainstem cavernous malformations can be achieved with an acceptable risk for long-term morbidity and surgery-related new deficits (~20 %). Neurological outcome is mainly determined within the first 6 months after surgery. Surgical treatment of brainstem cavernous malformations is recommended in symptomatic patients, in whom the lesion is accessible for surgery.

Hemorrhage risk, surgical management, and functional outcome of brainstem cavernous malformations

OBJECT

The aim of this study was to evaluate the pre- and postoperative rehemorrhage risk, neurological function outcome, and prognostic factors of surgically treated brainstem cavernous malformations (CMs) with long-term follow-up.

METHODS

The authors conducted a retrospective review of the clinical data from 242 patients with brainstem CMs that were surgically treated between 1999 and 2010. Patient charts, imaging findings, and outcomes were examined.

RESULTS

The study included 242 patients, with a male-to-female ratio of 1.3 and mean age of 32.6 years. The mean modified Rankin Scale scores on admission, at discharge, at 3 and 6 months after surgery, and at recent evaluation were 2.2, 2.6, 2.3, 1.8, and 1.5, respectively. The preoperative calculated annual hemorrhage and rehemorrhage rates were 5.0% and 60.9%, respectively. The complete resection rate was 95%. Surgical morbidity occurred in 112 patients (46.3%). Eighty-five patients (35.1%) demonstrated worsened condition immediately after surgery; 34 (41.0%) and 51 (61.4%) of these patients recovered to their baseline level within 3 and 6 months after surgery, respectively. At a mean follow-up of 89.4 months, the patients' condition had improved in 147 cases (60.7%), was unchanged in 70 cases (28.9%), and had worsened in 25 cases (10.3%). A total of 8 hemorrhages occurred in 6 patients, and the postoperative annual hemorrhage rate was 0.4%. Permanent morbidity remained in 65 patients (26.9%). The adverse factors for preoperative rehemorrhage were age ≥ 50 years, size ≥ 2 cm, and perilesional edema. The risk factors for postoperative hemorrhage were developmental venous anomaly and incomplete resection. The independent adverse factors for long-term outcome were increased age, multiple hemorrhages, ventral-seated lesions, and poor preoperative status. Favorable, complete improvement in the postoperative deficits over time was correlated with good preoperative neurological function and continuing improvement thereafter.

CONCLUSIONS

Favorable long-term outcomes and significantly low postoperative annual hemorrhage rates were achieved via surgery. Total resection should be attempted with an aim of minimal injury to neurological function; however, postoperative deficits can improve during the postoperative course. Close follow-up with radiological examination is proposed for patients with adverse factors predictive of rehemorrhage.

Stereotactic radiosurgery of intracranial cavernous malformations

Despite increasing worldwide experience, the role of stereotactic radiosurgery (SRS) in the management of cerebral cavernous malformations (CMs) remains controversial. Microsurgical excision of easily accessible CMs is typically safe; therefore, removal remains the gold standard for most of the symptomatic hemispheric lesions. However, there is now sufficient evidence supporting the use of SRS for the difficult cases. Waiting for the cumulative morbidity of the natural history to justify intervention does not serve the patient's interest, therefore, we argue for early radiosurgical intervention. Carefully designed randomized controlled trials might resolve controversies concerning the role of SRS in treating cerebral CMs.

Comparative studies of the diagnosis and treatment of cerebral cavernous malformations in adults: systematic review

BACKGROUND

Cerebral cavernous malformation (CCM) management decisions are usually made after CCM diagnosis is suspected or definitively diagnosed on axial imaging by indirectly comparing a surgeon's estimate of operative morbidity and mortality against published estimates of CCM untreated clinical course.

METHODS

We used comprehensive electronic strategies to search OVID Medline and EMBASE for original studies published before 2011 of ≥20 adults with CCM that (a) evaluated diagnostic test accuracy, or (b) compared treatment with microsurgery or stereotactic radiosurgery against conservative management in a concurrent or historical control group and reported clinical outcome(s). We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group's approach to identify level 1 or level 2 studies according to the Oxford Centre for Evidence-Based Medicine's 2011 criteria.

RESULTS

We found one eligible diagnostic test accuracy study of 72 patients with brain masses accompanied by vasogenic edema and substantial amounts of blood, which found that hyperintense perilesional signal on T1-weighted magnetic resonance imaging could differentiate CCM from other causes with excellent specificity (98 %) and reasonable sensitivity (62 %). We found five potentially eligible observational studies of adults with a CCM that had already bled, but none met level 2 criteria for a "dramatic" effect (the conventionally calculated probability of the two groups of observations coming from the same population should be less than 0.01 and a rate ratio greater than 10). We found 11 potentially eligible observational studies of adults with CCM and epilepsy, but nine studies did not demonstrate dramatic effects and the remaining two studies showed dramatic effects, but they were at high risk of bias.

CONCLUSIONS

To address the absence of level 1 or 2 evidence to support CCM treatment decisions, there is a need for large studies of CCM treatment with a concurrent control group, ideally with randomized treatment allocation.

Use of microscope-integrated near-infrared indocyanine green videoangiography in the surgical treatment of intramedullary cavernous malformations: report of 8 cases

OBJECT

The characteristics and efficacy of indocyanine green (ICG) videoangiography in cavernous malformation (CM) have not been fully elucidated. The purpose of this paper is to examine the potential utility of ICG videoangiography in the surgical treatment of intramedullary CMs.

METHODS

The authors conducted a retrospective review of 8 cases involving 5 men and 3 women who had undergone surgery for intramedullary CM between January 2008 and July 2011. All patients were evaluated by means of MRI. The MRI findings and clinical history in all cases suggested intramedullary CM as a preoperative diagnosis. In 2 of 8 cases, dilated venous structures associated with CMs were demonstrated. In one of these cases, there were coexisting extramedullary CMs. Intraoperatively, ICG fluorescence was observed for 5 minutes using microscope-integrated videoangiography.

RESULTS

In all 8 cases, intra- and extramedullary CMs were seen as avascular areas on ICG videoangiography. Indocyanine green videoangiography helped surgeons to localize and predict margins of the lesions before performing myelotomy. Importantly, in the cases with associated venous anomalies, ICG videoangiography was useful in delineating and preserving the venous structures. In extramedullary CMs located dorsal to the spinal cord, gradual ICG infiltration was seen, starting at 110 seconds and maximal at 210 seconds after injection. Postoperative MRI confirmed total removal of the lesions in all cases, and subsequent recovery of all patients was uneventful.

CONCLUSIONS

Indocyanine green videoangiography provided useful information with regard to the detection of lesion margins by demonstrating intramedullary CMs as avascular areas. In cases associated with venous anomalies, ICG contributed to safe and complete removal of the CMs by visualizing the venous structure. In extramedullary CMs, ICG videoangiography demonstrated the characteristic of slow blood flow within CMs.

Risk for symptomatic hemorrhage of cerebral cavernous malformations during pregnancy

Object

The threat of symptomatic hemorrhage from cerebral cavernous malformations (CCMs) during pregnancy remains poorly understood. The authors undertook this study to better define the risk of pregnancy-related hemorrhage in this population.

Methods

The records of female patients with sporadic (isolated lesions and negative family history) and familial forms of CCM, which were collected as part of the Barrow Neurological Institute CCM natural history study, were examined. Clinical data related to pregnancy, including type of delivery (vaginal or cesarean section) and any change in neurological status, were obtained from chart reviews and patient interviews.

Results

There were 168 pregnancies among 64 female patients with CCM (28 sporadic and 36 familial). Assuming an average of 46 weeks per pregnancy (40 weeks of gestation and 6 weeks of puerperium), patients were at risk for hemorrhage for a total of 148.6 years. Symptomatic hemorrhage (defined as new-onset or exacerbation of seizure activity or any change in neurological status) occurred during 5 pregnancies, with the most common symptom being seizures (4 cases). The overall risk for symptomatic hemorrhage was 3% per pregnancy; the risk was 1.8% per pregnancy in the sporadic group and 3.6% per pregnancy in the familial patients.

There were 19 deliveries by cesarean section: 5 for obstetrical reasons, 8 for fear of possible hemorrhage, and 6 for unknown reasons. Vaginal delivery was performed without complications for the remaining 149 pregnancies.

Conclusions

The authors' experience suggests that the risk of symptomatic hemorrhage from a CCM during pregnancy is not increased and that a history of CCM is not a contraindication to pregnancy or vaginal delivery.

Resection of a pontine cavernous malformation via an endoscopic endonasal approach: a case report

BACKGROUND AND IMPORTANCE

Cavernous malformations of the brainstem are a dilemma in terms of deciding when to operate, and they remain difficult to access surgically. We present a novel approach for the resection of a brainstem cavernous malformation.

CLINICAL PRESENTATION

A 59-year-old woman presented with a 1-month history of intermittent dysarthria, right facial weakness, and left arm and leg weakness. A magnetic resonance image revealed a 2-cm mass in the pons with blood products of differing ages, consistent with a cavernous malformation. We discussed with her the risks of surgical resection and conservative management. She decided to pursue conservative management. Two weeks later, she returned to the emergency room with diplopia and left-sided hemiplegia. Acute hemorrhage within the right pons was seen. She then chose to undergo surgical resection.

CONCLUSION

The patient underwent an endoscopic transnasal approach for resection of a pontine cavernous malformation. Image guidance was used to identify key anatomic landmarks. A gross total resection was achieved without new neurological deficits. With physical and occupational therapy, the patient developed antigravity strength in her left upper and lower extremities before discharge. At her 4-week follow-up, she was ambulating independently with the assistance of a cane. We report the successful gross total resection of a pontine cavernous malformation via an endoscopic transnasal approach. This patient had improvement in neurological symptoms after surgical resection with minimal surgical morbidity. Technologic advances in endoscopic skull base approaches have provided access to lesions of the skull base previously requiring more invasive approaches.

Anterior subtemporal approach for posterolateral brainstem cavernomas: report of ten cases

BACKGROUND

The neuronavigation-assisted anterior subtemporal approach is proposed in this article as an alternative to surgery of posterolateral brainstem cavernomas. Brainstem cavernomas represent a neurosurgical challenge because of the high morbidity and mortality rate related to their surgical removal. Several nerve nuclei, ascending and descending fibers make this region at high risk of serious postoperative deficits.

METHODS

Between 1998 and 2010, 24 patients underwent surgical removal of brainstem cavernomas in our institution. Ten of these patients presented a cavernous malformation in the posterolateral region of the brainstem and underwent surgical removal by means of a neuronavigation-assisted anterior subtemporal approach.

RESULTS

Lesion removal was complete for all patients. There were no cases of surgery-related death. Neurological status improved or remained unchanged after surgery in all cases. All patients presented good outcomes at 12 to 154 months' follow-up (mean 70 months; GOS = 5 in 8/10 patients, 4 in 2/10 patients; mRS = 0-1 in all patients). Only one patient presented transient confusion, aphasia and seizures related to temporal lobe swelling, which resolved completely within a few days. One patient developed cranial nerve III palsy and left hemiparesis with gradual recovery.

CONCLUSIONS

This approach represents a valid alternative to the "more classical" approaches for the surgery of posterolateral cavernomas of the pontomesenchephalic junction reaching the tentorial incisura, reducing the risk of damaging the vein of Labbé, temporal lobe swelling, cerebellar swelling, ophtalmoparesis, fourth ventricle cranial nerve nuclei lesions. Skeletonization of sigmoidal sinus provides with good outcomes, low morbidity and mortality.

Brainstem cavernomas: a surgical challenge

OBJECTIVE

The authors show their experience with brainstem cavernomas, comparing their data with the ones of a literature review.

METHODS

From 1998 to 2009, 13 patients harboring brainstem cavernomas underwent surgical resection. All plain films, medical records and images were reviewed in order to sample the most important data regarding epidemiology, clinical picture, radiological findings and surgical outcomes, as well as main complications.

RESULTS

The mean age was 42.4 years (ranging from 19 to 70). No predominant gender: male-to-female ratio, 6:7. Pontine cases were more frequent. Magnetic resonance imaging was used as the imaging method to diagnose cavernomas in all cases. The mean follow-up was 71.3 months (range of 1 to 138 months). Clinical presentation was a single cranial nerve deficit, VIII paresis, tinnitus and hearing loss (69.2%). All 13 patients underwent resection of the symptomatic brainstem cavernoma. Complete removal was accomplished in 11 patients. Morbidity and mortality were 15.3 and 7.6%, respectively.

CONCLUSIONS

Cavernomas can be resected safely with optimal surgical approach (feasible entry zone) and microsurgical techniques, and the goal is to remove all lesions with no cranial nerves impairment.

Surgical resection of cavernous malformations of the brainstem: evolution of a minimally invasive technique

OBJECTIVE

The purpose of this study is to provide an institutional retrospective review of surgically treated brainstem cavernous malformations.

METHODS

Between 2005 and 2010, 22 consecutive patients with brainstem cavernous malformations (15 female and 7 male) with a mean age of 43 years underwent surgical treatment. Mean volume of the resected cavernous malformations was 0.65 cm(3). A minimally invasive resection technique was used for these cases, in conjunction with skull base approaches.

RESULTS

The mean follow-up period was 26.6 months (range, 4-68 months). Of the 22 patients, 9% did not have clear evidence of hemorrhage at the time of presentation. Of the remainder, 22% had two or more instances of hemorrhage documented by magnetic resonance imaging. After resection and during follow-up, 54% of patients had an improvement in their modified Rankin scale, whereas 14% were worse compared with their preoperative presentation; 32% were unchanged and 9% of patients were found to have residual cavernoma post-surgery.

CONCLUSION

Our longitudinal experience has guided us to emphasize minimally invasive approaches during resection of the brainstem cavernous malformations, occasionally at the expense of achieving a complete resection, to improve patient outcomes.

Susceptibility-weighted imaging at 7 T: Improved diagnosis of cerebral cavernous malformations and associated developmental venous anomalies

Background and aim

In the diagnosis of cerebral cavernous malformations (CCMs) magnetic resonance imaging is established as the gold standard. Conventional MRI techniques have their drawbacks in the diagnosis of CCMs and associated venous malformations (DVAs). The aim of our study was to evaluate susceptibility weighted imaging SWI for the detection of CCM and associated DVAs at 7 T in comparison with 3 T.

Patients and methods

24 patients (14 female, 10 male; median age: 38.3 y (21.1 y–69.1 y) were included in the study. Patients enrolled in the study received a 3 T and a 7 T MRI on the same day. The following sequences were applied on both field strengths: a T1 weighted 3D GRE sequence (MP-RAGE) and a SWI sequence. After obtaining the study MRIs, eleven patients underwent surgery and 13 patients were followed conservatively or were treated radio-surgically.

Results

Patients initially presented with haemorrhage (n = 4, 16.7%), seizures (n = 2, 8.3%) or other neurology (n = 18, 75.0%). For surgical resected lesions histopathological findings verified the diagnosis of CCMs. A significantly higher number of CCMs was diagnosed at 7 T SWI sequences compared with 3 T SWI (p < 0.05). Additionally diagnosed lesions on 7 T MRI were significantly smaller compared to the initial lesions on 3 T MRIs (p < 0.001). Further, more associated DVAs were diagnosed at 7 T MRI compared to 3 T MRI.

Conclusion

SWI sequences at ultra-high-field MRI improve the diagnosis of CCMs and associated DVAs and therefore add important pre-operative information.

Surgical treatment of symptomatic cerebral cavernous malformations in eloquent brain regions

BACKGROUND

Despite the increased risk of hemorrhage and deteriorating neurological function of once-bled cerebral cavernous malformations (CM), the management of eloquently located CMs remains controversial.

METHODS

All eloquently located CMs (n = 45) surgically treated between 03/2006 and 04/2011 in our department were consecutively evaluated. Eloquence was characterized according to Spetzler and Martin's definition. The following locations were approached: brainstem, n = 16; sensorimotor, n = 8; visual pathway, n = 7; cerebellum (deep nuclei and peduncles), n = 7; basal ganglia, n = 4, and language, n = 3. Follow-up data was available for 41 patients (91 %) with a median interval of 14 months. Outcomes were evaluated according to the Glasgow outcome and the modified Rankin scale.

RESULTS

Immediately after surgery, 47 % (n = 21) had a new deficit. At follow-up, 80 % (n = 36) recovered to at least preoperative status or were better than before surgery, 9 % (n = 4) exhibited a slight, and 7 % (n = 3) had a moderate neurological impairment. Only two cases (4 %) with a new permanent severe deficit were observed, both related to dorsal brainstem surgery. The outcome after the surgery of otherwise located brainstem CMs was as beneficial as that for non-brainstem CMs. Patients with initially poor neurological performance fared worse than oligosymptomatic patients.

CONCLUSIONS

Despite the high postoperative transient morbidity, the majority improved profoundly during follow-ups. Compared with natural history, surgical treatment should be considered for all eloquent symptomatic CMs. Dorsal brainstem location and poor preoperative neurological status are associated with an increased postoperative morbidity.

Cerebral Cavernous Malformations and Pregnancy

BACKGROUND:

Cerebral cavernous malformations are brain vascular malformations associated with intracranial hemorrhage. It is unclear whether pregnancy is a risk factor for hemorrhage, yet there is speculation that it may be.

OBJECTIVE:

To compare the risk of clinically significant hemorrhage during pregnancy and nonpregnancy.

METHODS:

A total of 186 patients from the University of Toronto Vascular Malformations Study Group were enrolled. The obstetrical history of each patient was collected and matched to their neurological history from the records of the study group. All hemorrhagic events occurring during childbearing years were associated with either a defined pregnancy risk period or nonpregnancy period. Patients were also asked to recall advice that they received from health care professionals regarding risk of hemorrhage in pregnancy.

RESULTS:

Among our patient population there were 349 pregnancies (283 live births) and 49 hemorrhages during childbearing years, 3 of which were during pregnancy but none during delivery or within 6 weeks post partum. The hemorrhage rate for pregnant women was 1.15% (95% confidence interval: 0.23-3.35) per person-year and 1.01% (95% confidence interval: 0.75-1.36) per person-year for nonpregnant women. Relative risk of pregnancy was 1.13 (95% confidence interval: 0.34-3.75) (P = .84). Neurosurgeons and obstetricians were the source of most hemorrhage risk advice. The majority of neurosurgeons suggested that the risk was unchanged, but the obstetricians were divided. Four patients never conceived, and 2 others began contraception because of the advice that they received.

CONCLUSION:

The risk of intracranial hemorrhage from cerebral cavernous malformations is likely not changed during pregnancy, delivery, or post partum.

Angiographic detection and characterization of "cryptic venous anomalies" associated with spinal cord cavernous malformations using flat-panel catheter angiotomography

BACKGROUND

Spinal cord cavernous malformations (CMs) are associated with 2 types of angiographically occult "cryptic venous anomalies," which differ in location with respect to the spinal cord. The anatomic distinction between superficial and intramedullary is important in that the latter heighten the risks of CM resection.

OBJECTIVE

To report the observations of both types of cryptic venous anomalies documented during spinal digital subtraction angiography enhanced with flat-panel catheter angiotomography (FPCA).

METHODS

Spinal digital subtraction angiography enhanced with FPCA was performed in 2 adult patients with magnetic resonance imaging--documented intramedullary spinal cord CMs and prominent, nonspecific flow voids at the same levels. FPCA was obtained by selective injection of left T4 (case 1) and left T9 (case 2) with 5F Cobra 2 catheters (Terumo, Japan) during a 20-second rotational acquisition. Thirty milliliters of a 75% saline and 25% contrast solution (Omnipaque 300; GE) was administered. The rotational data set was reconstructed on a dedicated workstation (Leonardo; Siemens, Erlangen, Germany) through the use of regular and high-resolution matrixes, 0.4- and 0.1-mm voxel size, respectively.

RESULTS

Spinal digital subtraction angiography was unremarkable in both cases. In case 1, FPCA findings indicated an atypical network of prominent posterior perimedullary veins. In case 2, FPCA identified radially oriented channels forming a caput medusae pattern collecting into an enlarged intramedullary vein.

CONCLUSION

The unique ability of FPCA to image the spinal venous system enables the angiographic detection and characterization of abnormal spinal veins associated with CMs. Differentiating between the types of associated cryptic venous malformations may aid in surgical planning because the intramedullary type is associated with a higher risk of surgical complication.

A new strategic neurosurgical planning tool for brainstem cavernous malformations using interactive computer graphics with multimodal fusion images

OBJECT

In this study, the authors used preoperative simulation employing 3D computer graphics (interactive computer graphics) to fuse all imaging data for brainstem cavernous malformations. The authors evaluated whether interactive computer graphics or 2D imaging correlated better with the actual operative field, particularly in identifying a developmental venous anomaly (DVA).

METHODS

The study population consisted of 10 patients scheduled for surgical treatment of brainstem cavernous malformations. Data from preoperative imaging (MRI, CT, and 3D rotational angiography) were automatically fused using a normalized mutual information method, and then reconstructed by a hybrid method combining surface rendering and volume rendering methods. With surface rendering, multimodality and multithreshold techniques for 1 tissue were applied. The completed interactive computer graphics were used for simulation of surgical approaches and assumed surgical fields. Preoperative diagnostic rates for a DVA associated with brainstem cavernous malformation were compared between conventional 2D imaging and interactive computer graphics employing receiver operating characteristic (ROC) analysis.

RESULTS

The time required for reconstruction of 3D images was 3-6 hours for interactive computer graphics. Observation in interactive mode required approximately 15 minutes. Detailed anatomical information for operative procedures, from the craniotomy to microsurgical operations, could be visualized and simulated three-dimensionally as 1 computer graphic using interactive computer graphics. Virtual surgical views were consistent with actual operative views. This technique was very useful for examining various surgical approaches. Mean (±SEM) area under the ROC curve for rate of DVA diagnosis was significantly better for interactive computer graphics (1.000±0.000) than for 2D imaging (0.766±0.091; p<0.001, Mann-Whitney U-test).

CONCLUSIONS

The authors report a new method for automatic registration of preoperative imaging data from CT, MRI, and 3D rotational angiography for reconstruction into 1 computer graphic. The diagnostic rate of DVA associated with brainstem cavernous malformation was significantly better using interactive computer graphics than with 2D images. Interactive computer graphics was also useful in helping to plan the surgical access corridor.

Stereotactic LINAC radiosurgery for the treatment of brainstem cavernomas

BACKGROUND

The management of deep-seated cerebral cavernous malformations (CCMs) is still controversial. Although surgery remains the treatment of choice in patients with recurrent hemorrhage, patients with CCMs located in the brainstem are in many cases not eligible for resection due to high procedure-related morbidity and mortality. We evaluated the long-term outcome of LINAC radiosurgery (LINAC-RS) for the treatment of brainstem CCMs.

PATIENTS AND METHODS

Between December 1992 and March 2008, 14 patients (6 men, 8 women) harboring brainstem CCMs underwent LINAC-RS. Pretreatment neuroimaging showed no associated developmental venous angiomas (DVAs) in any of our patients. Prior to treatment, all patients suffered at least from one symptomatic hemorrhage (median 1.8, range 1–3). A median follow-up of 7.1 years (range 2.0–16.8 years) could be obtained in 12 patients. We applied a median tumor surface dose of 13.9 Gy (range 11–18 Gy; median tumor volume 1.6 ml, range 0.4–4.3 ml).

RESULTS

Following LINAC-RS, neurological outcome improved in 4 (33.3%) and remained unchanged in 8 patients (66.7%). Rebleeding with subsequent transient neurological status deterioration occurred in 4 patients (33.3%), leading to additional surgical resection in 2 patients (16.7%). The corresponding annual hemorrhage rate was 4.8% (4/82.8 patient–years). Adverse radiation effects (ARE, defined by perilesional hyperintensity on T2-weighted MR images) were revealed in 3 patients (25%), leading to transient neurological deficits in 2 patients (16.7%). There were no procedure-related complications leading to either permanent morbidity or mortality.

CONCLUSION

Our results support the role of LINAC-RS as an efficient and safe treatment to significantly reduce the annual hemorrhage rate in patients suffering from brainstem CCMs not eligible to microsurgery. Compared with radiosurgery for arteriovenous malformations (AVMs), the intervention-related morbidity is higher.

The natural history of intracranial cavernous malformations

Literature reports on the natural history of cerebral cavernous malformations (CMs) are numerous, with considerable variability in lesion epidemiology, hemorrhage rates, and risk factors for hemorrhage. In this review, the authors performed a meta-analysis of 11 natural history studies. The overall male-to-female ratio was 1:1, and the mean age at presentation was 30.6 years. Overall, 37% of patients presented with seizures, 36% with hemorrhage, 23% with headaches, 22% with focal neurological deficits, and 10% were asymptomatic. Some patients had more than one symptom. Seizure presentation was most prevalent among supratentorial CMs, while focal neurological deficits were common in patients with infratentorial CMs. By location, CMs were in the cerebral hemispheres (66%), brainstem (18%), basal ganglia or thalamus (8%), cerebellum (6%), and other (2.5% [combined supra- and infratentorial, callosal or insular]). Overall, 19% of patients harbored multiple intracranial CMs, and 9% had radiographically apparent associated developmental venous anomalies. An overall annual hemorrhage rate of 2.4% per patient-year (range 1.6%-3.1%) was identified across 3 studies. Prior hemorrhage and female sex were risk factors for bleeding, while CM size and multiplicity did not affect hemorrhage rates. Although not impacting the hemorrhage rate itself, deep location was a risk factor for increased clinical aggressiveness.

Massive intracerebral hemorrhage caused by a cavernous malformation

We present a rare case of massive intracerebral hemorrhage resulting from a small, superficially-located supratentorial cavernous malformation, or cavernoma. These lesions rarely lead to massive, life-threatening intracerebral hemorrhages. A 17-year-old female presented with a 3-week history of declining mental status. Brain computed tomography and magnetic resonance imaging revealed a sizable intracranial hemorrhage, within the right occipital region, associated with a small nodule at the hematoma's posterior margin. An emergency operation removed the entire hematoma and nodule. Histological examination of the nodule was compatible with a diagnosis of cavernous malformation. The patient's post-operative course was uneventful.

Natural history and imaging prevalence of cavernous malformations in children and young adults

OBJECT

This study was undertaken to define the age-related prevalence of cavernous malformations (CMs) in children and young adults undergoing intracranial imaging. In addition, the authors aim to clarify the natural history of CMs in young people, especially in those with incidentally discovered lesions.

METHODS

To identify those patients with CMs, the authors retrospectively reviewed the electronic medical records of 14,936 consecutive patients 25 years of age or younger who had undergone brain MR imaging. In patients with a CM, clinical and imaging data were collected. Patients with untreated cavernomas who had more than 6 months of clinical and MR imaging follow-up were included in a natural history analysis. The natural history analysis included 110 CMs in 56 patients with a 3.5-year mean clinical follow-up interval (199 patient-years and 361 cavernoma-years).

RESULTS

In 92 patients (0.6%), 164 CMs were identified. The imaging prevalence of cavernomas increased with advancing age (p = 0.002). Multiple CMs occurred in 28 patients (30%), and 8 patients (9%) had a family history of multiple CMs. Fifty patients (54%) presented with symptoms related to the cavernoma, of whom 30 presented with hemorrhage (33%). Of the 164 cavernomas identified, 103 (63%) were considered incidental, asymptomatic lesions. Larger size was associated with acute symptomatic presentation (p = 0.0001). During the follow-up interval, 6 patients with 8 cavernomas developed 11 symptomatic hemorrhages after initial identification. Five of the patients who had a hemorrhage during the follow-up interval had initially presented with hemorrhage, while only 1 had presented incidentally. The hemorrhage rate for all patients in the natural history group was 1.6% per patient-year and 0.9% per cavernoma-year. The hemorrhage rate was 8.0% per patient-year in the symptomatic group versus 0.2% in the incidental group. Symptomatic hemorrhage after long-term follow-up was associated with initial acute presentation (p = 0.02).

CONCLUSIONS

The imaging prevalence of CM increases with advancing age during childhood. Patients presenting without hemorrhage have a significantly lower risk of bleeding compared with those who present with acute neurological symptoms. Comparing this series of children to prior analyses of CM natural history in adults, the authors' data do not suggest a higher bleeding risk in younger patients.

Untreated clinical course of cerebral cavernous malformations: a prospective, population-based cohort study

BACKGROUND

Cerebral cavernous malformations (CCMs) are prone to bleeding but the risk of intracranial haemorrhage and focal neurological deficits, and the factors that might predict their occurrence, are unclear. We aimed to quantify these risks and investigate whether they are affected by sex and CCM location.

METHODS

We undertook a population-based study using multiple overlapping sources of case ascertainment (including a Scotland-wide collaboration of neurologists, neurosurgeons, stroke physicians, radiologists, and pathologists, as well as searches of registers of hospital discharges and death certificates) to identify definite CCM diagnoses first made in Scottish residents between 1999 and 2003, which study neuroradiologists independently validated. We used multiple sources of prospective follow-up both to identify outcome events (which were assessed by use of brain imaging, by investigators masked to potential predictive factors) and to assess adults' dependence. The primary outcome was a composite of intracranial haemorrhage or focal neurological deficits (not including epileptic seizure) that were definitely or possibly related to CCM.

FINDINGS

139 adults had at least one definite CCM and 134 were alive at initial presentation. During 1177 person-years of follow-up (completeness 97%), for intracranial haemorrhage alone the 5-year risk of a first haemorrhage was lower than the risk of recurrent haemorrhage (2·4%, 95% CI 0·0-5·7 vs 29·5%, 4·1-55·0; p<0·0001). For the primary outcome, the 5-year risk of a first event was lower than the risk of recurrence (9·3%, 3·1-15·4 vs 42·4%, 26·8-58·0; p<0·0001). The annual risk of recurrence of the primary outcome declined from 19·8% (95% CI 6·1-33·4) in year 1 to 5·0% (0·0-14·8) in year 5 and was higher for women than men (p=0·01) but not for adults with brainstem CCMs versus CCMs in other locations (p=0·17).

INTERPRETATION

The risk of recurrent intracranial haemorrhage or focal neurological deficit from a CCM is greater than the risk of a first event, is greater for women than for men, and declines over 5 years. This information can be used in clinical practice, but further work is needed to quantify risks precisely in the long term and to understand why women are at greater risk of recurrence than men.

FUNDING

UK Medical Research Council, Chief Scientist Office of the Scottish Government, and UK Stroke Association.

Gamma knife stereotactic radiosurgery for thalamic & brainstem cavernous angiomas

OBJECTIVE

To determine the safety and efficacy of Gamma Knife stereotactic radiosurgery (GKS) in the treatment of patients with symptomatic cavernous angiomas (CA) of the brainstem or thalamus, by comparing overall outcome to the natural history of the disease.

METHODS

Over 10 years a series of 16 consecutively presenting patients (M = 9, F = 7) with thalamic or brainstem CA were treated with GKS to a single lesion, specifically excluding the haemosiderin ring from the target. Within the year prior to treatment eight patients had suffered one symptomatic haemorrhage and eight had suffered more than one symptomatic haemorrhage. Mean age at treatment was 38.9 (15-55) years. Mean prescription dose 13.31 Gray (11.0 Gy-16.0 Gy). Patients were followed up radiologically and, more importantly, clinically for a mean period of 43.8 (11-101) months, median 36 months.

RESULTS

One patient suffered recurrent haemorrhage at 23 months post-GKS, but has not re-bled in the following 61 months. One patient died of thalamic haemorrhage from the treated lesion at 90 months. One patient was lost to follow up. There have been no other clinical episodes or radiological findings to suggest post-GKS haemorrhage in the remaining 13 patients, and no other complications were observed in the treated population. The annual haemorrhage rate within the first two years post GKS was 3.72% and the annual haemorrhage rate 2 years post GKS was 3.59% per annum.

CONCLUSION

With the dose regimens described, GKS is safe and effective in the treatment of thalamic and brainstem CA, as assessed by significant reduction in observed rate of re-haemorrhage over that expected from the known natural history of those CAs which have already demonstrated a tendency to haemorrhage in highly eloquent areas.

Persistent hiccups (singultus) as the presenting symptom of medullary cavernoma

BACKGROUND

Singultus (hiccup) is common, usually transient, and only rarely indicative of disease. If it persists, it can be highly bothersome, potentially interfering with sleep and leading to depression and physical exhaustion. It is presumed to be due to a disturbance in a reflex arc that includes the brainstem, the phrenic nerve, the vagus nerve, and the sympathetic chain. It can be induced by mechanical irritation (e.g., gastric distention), metabolic or toxic irritation (e.g., alcohol, cigarette smoke), infectious processes, emotional disturbances, and, rarely, neurological diseases.

CASE DESCRIPTION

The patient presented with persistent singultus (by definition, singultus lasting more than 48 hours). Initial diagnostic tests failed to reveal the cause, and the hiccups failed to respond to medications and other attempted treatments. Finally, an imaging study revealed a medullary cavernoma. After neurosurgical resection of this lesion, the patient was asymptomatic and returned to work.

CONCLUSION

This case shows that singultus, though it may seem trivial, deserves to be taken seriously, particularly when it persists and does not respond to medications. Its cause can be discovered in timely fashion by means of a thorough clinical history, physical examination, and ancillary testing.

Management of incidentally discovered intracranial vascular abnormalities

With the widespread use of brain imaging studies, neurosurgeons have seen a marked increase in the number of incidental intracranial lesions, including vascular abnormalities. Specifically, the detection of incidentally discovered aneurysms, arteriovenous malformations, cavernous angiomas, developmental venous anomalies, and capillary telangiectasias has increased. The best management strategy for most of these lesions is controversial. Treatment options include observation, open surgery, endovascular procedures, and radiosurgery. Multiple factors should be taken into account when discussing treatment indications, including the natural history of the disease and the risk of the treatment. In this article, the authors focus on the natural history of these lesions and the risk of the treatment, and they give recommendations regarding the most appropriate management strategy based on the current evidence in the literature and their experience with intracranial vascular abnormalities.

Management of incidental cavernous malformations: a review

Cavernous malformations (CMs) are angiographically occult vascular malformations that are frequently found incidentally on MR imaging. Despite this benign presentation, these lesions could cause symptomatic intracranial hemorrhage, seizures, and focal neurological deficits. Cavernomas can be managed conservatively with neuroimaging studies, surgically with lesion removal, or with radiosurgery. Considering recent studies examining the CM's natural history, imaging techniques, and possible therapeutic interventions, the authors provide a concise review of the literature and discuss the optimal management of incidental CMs.

"Kissing" brainstem cavernous angiomas removed using a trans-fourth ventricular floor approach--case report

A 39-year-old woman presented with a rare case of "kissing" brainstem cavernomas formed by separate lesions enlarging with simultaneous recurrent hemorrhages, which was successfully treated by staged resection using a trans-fourth ventricular floor approach. She had a familial history of cerebral cavernous angioma, and presented with a history of four episodes of sudden neurological deterioration. Magnetic resonance (MR) imaging obtained at each neurological event demonstrated two distinct brainstem cavernomas located in the pontine tegmentum and ventral part of the lower pons, both of which enlarged stepwise caused by simultaneous recurrent hemorrhages. Both cavernomas contacted and formed "kissing" lesions. She underwent midline suboccipital craniotomy in the prone position. The cavernoma in the pontine tegmentum was resected through a trans-fourth ventricular floor approach. Although "kissing" formation appeared on preoperative MR imaging, parenchyma was identified at the bottom of the removal cavity of the dorsal lesion, and resection was terminated. MR imaging following the first surgery revealed complete resection of the pontine tegmentum cavernoma and the ventral pontine cavernoma, which was located adjacent to the bottom of the removal cavity and aligned in same direction along the fourth ventricular floor approach. At 10 days after first surgery, she underwent the same procedure with the aid of neuronavigation to resect the ventral pontine cavernoma through the former removal cavity. This approach through the previous removal route, particularly for resection of "kissing" lesions which are difficult to access in the brainstem, is a technically feasible microsurgical procedure.

Subtemporal transtentorial resection of cavernous malformations involving the pyramidal tract in the upper pons and mesencephalon

BACKGROUND

Lateral approaches to the brain stem for the resection of the cavernous malformations are preferred in order to avoid the structures within the floor of the fourth ventricle. The entry behind the pyramidal tract (PT) is usually carried out through the posterolateral surface of the brain stem. The more straightforward lateral approach below the temporal lobe is used rarely because of potential risks.

METHODS

The outcome after resection of the cavernomas involving the PT in the mesencephalon and the upper pons via the subtemporal transtentorial approach in nine patients was analysed. Mapping of the PT by direct electrical stimulation was used in the last four patients.

RESULTS

The subtemporal transtentorial approach enabled adequate exposure of the lateral and anterolateral surface of the midbrain and the upper pons. No adverse events from the elevation of the temporal lobe were encountered. Direct electrical stimulation using a bipolar electrode with the parameters of 100 Hz, 1 ms, and 3-9 mA evoked motor responses in three of four patients. It allowed placing the incision in the lateral surface of the midbrain behind the PT or between the fibres of the upper and the lower extremity. No worsening of the PT functions was observed in the series.

CONCLUSIONS

The subtemporal transtentorial approach enables adequate exposure of the lateral and the anterolateral surface of the mesencephalon and upper pons, allowing neurophysiological mapping of the PT and thus avoiding its damage during removal of the cavernoma.

The challenge of access to the pontomesencephalic junction: an anatomical study of lateral approach and exposure

We quantitatively compared relative merits of lateral approaches to the pontomesencephalic junction (PMJ): anterior petrosectomy, subtemporal transtentorial, posterior petrosectomy, and retrosigmoid transtentorial. In dissected cadaveric heads, lengths of exposure were measured anteriorly from CN V along the pontomesencephalic sulcus (PMS); posterosuperiorly along the lateral mesencephalic sulcus (LMS); and posteroinferiorly along the interpeduncular sulcus (IPS). Subtemporal transtentorial approach provided best anterior exposure along the PMS (23.8 ± 4.5 mm). Posterosuperior exposures were comparable for all approaches except anterior petrosectomy (limited). Posteroinferior exposure was most with subtemporal transtentorial approach (13.2 ± 2.8 mm). CN V entry/exit point was identified through all approaches, except for subtemporal transtentorial; shortest surgical depth with posterior petrosectomy was 43.7 ± 5.5 mm. PMS-LMS-IPS convergence point: reached through all approaches, except for anterior petrosectomy (limited); shortest surgical depth with posterior petrosectomy was 40.3 ± 4.3 mm. Anterior petrosectomy provides direct anterolateral views of the pons not afforded by subtemporal approach. Subtemporal transtentorial approach provides optimal posterolateral view to the PMJ and cerebellar peduncles. Retrosigmoid transtentorial approach offers wide exposure of the lateral surface, limited on the posteroinferior PMJ by the cerebellum. The small opening of posterior petrosectomy creates an awkward corridor to anterior PMJ targets but provides a direct and shortest route to the cerebellar peduncles.

A single institution series of cavernomas of the brainstem

We retrospectively analyzed a series of patients with brainstem cavernomas of the medulla, pons, or midbrain to attempt to define the natural history, indications for surgery, and outcome after surgical resection. Between 1993 and 2008, 52 patients with cavernomas of the brainstem presented to our institute and were managed either surgically or conservatively. Twenty-three patients underwent surgical excision using standard skull base approaches. Outcomes were correlated to the number of preoperative hemorrhages, location of the cavernoma, timing of surgery in relation to the hemorrhage and the preoperative neurological status. Nine patients improved after surgery, 12 deteriorated and two died. In the conservatively managed group, 15 patients had a good outcome, 11 deteriorated and one died. Multiple hemorrhages, poor preoperative neurological status and surgery during the acute phase were predictive of the surgical outcome. Excision of brainstem cavernomas should be considered in patients with symptomatic hemorrhages whose lesions approach the pial surface. Patients with minimal stable neurologic deficits without recurrent bleeds should be managed conservatively.

Surgical strategies in treating brainstem cavernous malformations

BACKGROUND

Optimal therapy of brainstem cavernous malformations (BSCMs) remains controversial because their biological behavior is unpredictable and surgical removal is challenging.

OBJECTIVE

To analyze our experience with BSCMs and to conduct a review of the literature to identify a rational approach to the management of these lesions.

METHODS

Fifty-five patients harboring 57 BSCMs underwent surgery and 17 patients were treated conservatively during the 10-year period from 1999 to 2008. The operative strategy was to perform complete CM resection and to preserve any associated venous malformation with minimal functional brainstem tissue sacrificed. The National Institutes of Health Strength Scale (NIHSS) was used to assess neurological status.

RESULTS

The average hemorrhagic and rehemorrhagic rates were 4.7% and 32.7% per patient-year, respectively. Total lesional resection was achieved in all operated patients. Their mean NIHSS score was 4.6 after the first episode, 3.5 preoperatively, 3.2 at discharge, and 1.4 after a mean follow-up of 49 months. Complete recovery rates of motor deficits and sensory disturbances from the preoperative state were 70.4% and 51.7%, respectively. Complete recovery rates for cranial nerves III, V, VI, and VII and the lower group were 60%, 63.2%, 25%, 57.1%, and 80%, respectively. For the conservative patients, the mean NIHSS score was 5.9 after the first episode and 1.7 after a mean follow-up of 40 months.

CONCLUSION

NIHSS is optimal for evaluating the natural history and surgical effect of patients harboring BSCMs. Surgical resection remains the primary therapeutic option after careful patient screening and preoperative planning.

Clinical practice guidelines in intracerebral haemorrhage

Intracerebral haemorrhage accounts for 10%-15% of all strokes; however it has a poor prognosis with higher rates of morbidity and mortality. Neurological deterioration is often observed during the first hours after onset and determines poor prognosis. Intracerebral haemorrhage, therefore, is a neurological emergency which must be diagnosed and treated properly as soon as possible. In this guide we review the diagnostic procedures and factors that influence the prognosis of patients with intracerebral haemorrhage and we establish recommendations for the therapeutic strategy, systematic diagnosis, acute treatment and secondary prevention for this condition.

Quality of Life After Brainstem Cavernoma Surgery in 71 Patients

BACKGROUND:

Symptomatic patients with a brainstem cavernoma are treated surgically with increasing frequency. Generally, the patient's benefit from this difficult surgical intervention is quantified by the assessment of neurological symptoms.

OBJECTIVE:

To document the beneficial effect of surgery in a larger patient population by assessing the postoperative quality of life (QoL).

METHODS:

In a series of 71 surgically treated patients, a detailed neurological status was assessed by Patzold Rating and Karnofsky Performance Status Scale. Patients rated their QoL with the Short Form 36 Health Survey. To document the effect of surgery on QoL, we devised a supplementary questionnaire. The last 24 patients completed Short Form 36 Health Survey pre- and postoperatively.

RESULTS:

Karnofsky Performance Status Scale improved in 44 of 71 surgical patients (62%), remained unchanged in 19 (27%), and deteriorated in 8 (11%) individuals. Patzold Rating showed a more detailed picture of the neurological symptoms. It correlated significantly with Karnofsky Performance Status Scale, which underscores its usefulness for patients with brainstem lesions. In the Short Form 36 Health Survey score, the Mental Component Summary improved with surgery (paired test, P = .015). In addition, 58 individuals (82%) declared a clear subjective benefit of surgery.

CONCLUSION:

The results of this large series support the notion that microsurgical removal of a brainstem cavernoma represents an effective therapy in experienced hands and is generally associated with good clinical outcome, both neurologically and in terms of QoL.

Acute onset of dizziness caused by a cavernous malformation lateral to the fourth ventricle: a case report

Dizziness, diplopia, and nystagmus may be nonspecific symptoms and in part attributed to central causes. We report a case with brain stem lesion and discuss these nonspecific symptoms. A 13-year-old boy presented to our emergency department with a lasting dizziness for 1 week and diplopia for 5 days. New onset horizontal nystagmus was also noted during the physical examination. A cavernous malformation in the right middle cerebral peduncle lateral to the fourth ventricle was suspected by brain computed tomography and confirmed by magnetic resonance imaging. Without progression of the lesion, conservative treatment and regular follow-up were performed. This case report demonstrates the importance of primary physicians paying attention to children with dizziness, diplopia, and nystagmus for considering possible central nervous problems.