Early radiologically proven rebleeding from intracranial cavernous angiomas: report of 6 cases and review of the literature

Pathophysiology and classification of intracranial and spinal dural AVF

Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. DAVFs are relatively rare, however, DAVFs can lead to significant morbidity and mortality due to intracranial hemorrhage and non-hemorrhagic neurologic deterioration related to leptomeningeal venous drainage. The etiology and pathophysiology of DAVFs is not fully understood. Several hypotheses for development of DAVF and classifications for predicting risk of hemorrhage and neurological deficit have been proposed to help clinical decision making according to its natural history. Herein, incidence, etiology, pathophysiology of development of intracranial and spinal DAVF including their classifications are briefly described with short historical review.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cerebral Cavernous Malformation: What a Practicing Clinician Should Know

Cavernous malformations (CMs) are angiographically occult, low-flow vascular malformations of the central nervous system. They are acquired lesions, with approximately 80% of patients having the sporadic form and 20% the familial form of the disease. The lesions may also develop years after radiotherapy. At the microscopic level, they consist of endothelium-lined cavities (or "caverns") containing blood of different ages. The endothelium proliferates abnormally, and tight junctions are absent or dysfunctional, resulting in leakiness of the endothelium and clinical manifestations in some patients. Cavernous malformations can be an incidental finding or can present with focal neurologic deficits, seizures, or headache, with or without associated hemorrhage. Management of the CM lesion requires knowledge of the natural history of the disease compared with the risk of surgical intervention. Surgery is often considered for symptomatic patients with lesions in a noneloquent location. Medical management is warranted for symptoms related to the CM. Research aimed at understanding the genes and signaling pathways related to CMs have provided potential drug targets, and clinical trials are underway to determine whether medications reduce the risk of future bleeding without surgery or modify the disease course. In addition, recent epidemiologic data have aided practitioners in determining how to treat comorbid conditions in patients with a potentially hemorrhagic lesion. This review provides an overview of the epidemiology, presentation, and clinical management of CMs.

Intraoperative Computed Tomography and Awake Craniotomy: A Useful and Safe Combination in Brain Surgery

BACKGROUND

Awake surgery is an effective technique to improve safety in surgical resection of lesions involving eloquent areas of the brain. Intraoperative imaging guidance and neuronavigation are widely applied in neurosurgical procedures. However, data on the application of intraoperative imaging to awake craniotomies are limited. We report our experience with intraoperative computed tomography (i-CT) during awake surgery, focusing on technical feasibility and effectiveness.

METHODS AND RESULTS

Four patients with a lesion located in an eloquent area of the brain-1 with a cavernous hemangioma, 1 with a high-grade glioma, and 2 with a low-grade glioma (LGG)-underwent awake surgery with neuronavigation guidance. In all patients, i-CT was used to evaluate the completeness of resection or the extent of residual tumor. Intraoperative ultrasound was also used during microsurgery to verify the presence of residual tumor. The use of i-CT us allowed to obtain updated images for neuronavigation and to correct for brain shift.

CONCLUSIONS

i-CT in awake surgery is reliable and effective. It does not significantly affect the duration of surgery and does not add stress for the patient. The possibility to correct for brain shift also in awake patients can increase the precision and accuracy of surgery, particularly in cases of LGG, avoiding the resection of normal white matter or tumor remnants in noneloquent areas.

Clinical Management of Cavernous Malformations

PURPOSE OF REVIEW

This study aims to review the current epidemiology and clinical management of patients with cavernous malformations (CM).

RECENT FINDINGS

Hemorrhage is the most feared complication and leads to morbidity in patients with CM. Multiple studies including three meta-analyses have provided useful estimates of hemorrhage risk, but have failed to identify a modifiable risk factor for prevention of cavernous malformation related hemorrhage. In treating the CM itself, surgical risk is weighed against the natural history. However, accumulating knowledge regarding the roles of CCM 1, 2, and 3 genes has led to the discovery of potential therapeutic targets. The risk of future hemorrhage in patients with CM is highest in those who have had previously clinical hemorrhages. Estimated risks are helpful in counseling patients and comparing to the risk of surgery. Future clinical trials of candidate medications are likely to target those patients with prior clinical hemorrhage in whom the surgical risk is deemed high.

Cerebral hemodynamic disturbance in dural arteriovenous fistula with retrograde leptomeningeal venous drainage: a prospective study using 123I-iodoamphetamine single photon emission computed tomography

OBJECT

The severity of cerebral hemodynamic disturbance caused by retrograde leptomeningeal venous drainage (RLVD) of a dural arteriovenous fistula (dAVF) is related to neurological morbidity and unfavorable outcome. However, the cerebral hemodynamics of this disorder have not been elucidated well. The aim of this study was to assess the relationship between the cerebral venous congestive encephalopathy represented as a high-intensity area (HIA) on T2-weighted MR images and the cerebral hemodynamics examined by 123I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT), as well as the predictive value of 123I-IMP SPECT for the development and reversibility of venous congestion encephalopathy.

METHODS

Based on the pre- and posttreatment T2 HIAs associated with venous congestion encephalopathy, patients were divided into 3 groups: a normal group, an edema group, and an infarction group. The regional cerebral blood flow (rCBF) at the region with RLVD was analyzed by 123I-IMP SPECT, and the results were compared among the groups.

RESULTS

There were 11, 6, and 3 patients in the normal, edema, and infarction groups, respectively. No patients in the normal group showed any symptoms related to venous congestion. In contrast, all patients in the edema and infarction groups developed neurological symptoms. The rCBF in the edema group was significantly lower than that in the normal group, and significantly higher than that in the infarction group. The cerebral vascular reactivity (CVR) of the infarction group was significantly lower than that of the normal and edema groups. After treatment, the neurological signs disappeared in the edema group, but only partial improvement was seen in the infarction group. The rCBF also significantly increased in the normal and edema groups, but not in the infarction group.

CONCLUSIONS

Quantitative rCBF measurement is useful for evaluating hemodynamic disturbance in dAVF with RLVD. The reduction of rCBF was strongly correlated with the severity of venous congestive encephalopathy, and loss of CVR is a reliable indicator of irreversible venous infarction caused by RLVD.

Technical, Anatomical, and Functional Study after Removal of a Symptomatic Cavernous Angioma Located in Deep Wernicke's Territories with Cortico-Subcortical Awake Mapping

Introduction. The subcortical region underneath Wernicke's area (WA) is a critical crossing of the eloquent language pathways involved in all semantic, phonological, syntactic, and working memory elaboration. We report the resection of a CA located underneath the dominant WA discussing the functional and anatomical evidence provided by fMRI, dissections with Klingler's technique, and intraoperative mapping during awake surgery. Case Report. A 64-year-old right-handed female affected by daily complex focal seizures underwent f-MRI, showing language activations in the middle and inferior temporal gyri and an unusual free entry zone in the “classical” WA. The cortical intraoperative mapping partially confirmed the f-MRI results, and we approached the lesion directly through WA. Subcortical DES allowed the identification of the eloquent language pathways and the radical resection of the perilesional gliotic rim. The patient did not report deficits and she is seizures and drug free after 1-year surgery. Discussion. Cortical DES demonstrated the variability of the eloquent areas within the cortex of the dominant temporal lobe. The subcortical DES confirmed the crucial role in language elaboration and the anatomical course of the bundles underneath WA. Conclusions. Awake surgery with DES represents a reliable and dynamic technique also for safer and functional-customized resection of CAs.

Awake mapping for resection of cavernous angioma and surrounding gliosis in the left dominant hemisphere: surgical technique and functional results: clinical article

OBJECT

Maximal resection of symptomatic cavernous angioma (CA), including its surrounding gliosis if possible, has been recommended to minimize the risk of seizures or (re)bleeding. However, despite recent neurosurgical advances, such extensive CA removal is still a challenge in eloquent areas. The authors report a consecutive series of patients who underwent awake surgery for CA within the left dominant hemisphere in which intraoperative cortical-subcortical electrical stimulation was used.

METHODS

Nine patients harboring a CA that was revealed by seizures in 6 cases and bleeding in 3 cases underwent resection. All CAs were located in the left dominant hemisphere: 3 temporal, 2 insular, 2 parietal, and 2 in the parietotemporal region. Awake mapping was performed in all cases by using intraoperative cortical-subcortical electrical stimulation and ultrasonography (except in 1 insular CA in which a neuronavigation system was used).

RESULTS

Total removal of the CA was achieved in all patients, with identification and preservation of language and sensory-motor structures. In addition, the pericavernomatous gliosis was removed in 7 cases, according to the functional boundaries provided by intraoperative subcortical stimulation. In 2 cases, subcortical mapping revealed eloquent areas within the surrounding gliosis, which was voluntarily avoided. There was no postsurgical permanent deficit, no rebleeding, and no epilepsy in 7 cases (2 patients had rare seizures in the 1st year or two after surgery, and then complete arrest), with a mean follow-up of 28.5 months (range 3-64 months).

CONCLUSIONS

These results suggest that intraoperative cortical-subcortical stimulation in awake patients represents a valuable adjunct to image-guided surgery with the aim of selecting the safer surgical approach for CAs involving eloquent areas. Moreover, such online mapping can be helpful when removing the pericavernomatous gliosis while preserving functional structures, which can persist within the hemosiderin rim. Thus, the authors propose that awake surgery be routinely considered, both to optimize the resection and to improve the quality of life through seizure control and avoidance of (re)bleeding for CAs located in the left dominant hemisphere.

Advances in the biology of cerebral cavernous malformations

OBJECT

To provide a review of current, high-impact scientific findings pertaining to the biology of cerebral cavernous malformations (CCMs).

METHODS

A comprehensive literature review was conducted using PubMed to examine the current literature regarding the molecular biology and pathophysiology of CCMs.

RESULTS

In this literature review, a comprehensive approach is taken to review the current scientific status of CCMs. This includes discussion of molecular biology and animal models, ultrastructure and angioarchitectural features and immunological methods and hypotheses.

CONCLUSIONS

Studies examining the molecular biology of CCMs have shown that genes involved in angiogenesis, blood-brain barrier formation, cell size regulation, vascular permeability and apoptosis play critical roles in the ontogeny of this disease. In vivo work suggests the likelihood of a "two-hit mechanism" resulting in somatic mosaicism and biallelic loss of angiogenic genes. The etiological effects of angioarchitecture and immune response within these lesions further complicate the pathophysiology. Future treatment endeavors will necessitate exploitation of the multiple facets of CCM formation to maximize success at CCM prevention or obliteration.

Does conservative management for brain stem cavernomas have better long-term outcome?

There has been a controversy in the last 15 years on the correct management of brain stem cavernomas. We have reviewed our experience of the last 10 years in a single Institution and reviewed related literature published in the last 15 years. We recorded the demographics, clinical presentation, rebleeding episodes, incidence of neurological events and outcome assessed by recording the change of the modified Rankin scale in 21 cases. Univariate analysis was applied to test the effect of demographics, and presentation on the incidence and timing of rebleeding, chance of having a new neurological event, the number of subsequent neurological events and outcomes. Six cases were treated with surgery and 15 cases were managed conservatively. We obtained follow-up data in 20 patients (95%). Mean follow-up period was 79.7 months (range: 6-244, median 70 months). There were 0.05 rebleeding events per patient-year and 0.1 episodes of neurological deterioration per patient-year. No mortality was noted in either the surgical or the non-surgical group. Three of the six surgical cases had a reoperation. The outcome was improved in one patient, unchanged in 1, and worse in 3 surgical patients. In the case of conservative management the outcome was improved in two patients, unchanged in five patients, and worse in eight patients. Outcome was worse in the case of multiple cavernomas (p = 0.012). Our findings suggest that conservative management may be appropriate in individual cases when compared with surgery, but this difference was not statistically significant enough in order to support a change in practice. The natural history of brain stem cavernomas appears more benign than previously thought.

A T1 hyperintense perilesional signal aids in the differentiation of a cavernous angioma from other hemorrhagic masses

BACKGROUND AND PURPOSE

A cavernous angioma is a developmental vascular malformation with a high risk of hemorrhage. The purpose of this work was to retrospectively determine whether an MR sign of T1 hyperintense perilesional signal intensity is useful for the differentiation of cavernous angioma from other hemorrhagic cerebral masses.

MATERIALS AND METHODS

The institutional review board approved this study. We retrospectively evaluated the MR images of 72 patients with acute or subacute cerebral hemorrhagic lesions with perilesional edema (29 cavernous angiomas, 13 glioblastomas, 1 oligodendroglioma, 16 metastatic tumors, and 13 intracerebral hemorrhages) for the presence of T1 hyperintense perilesional signal intensity. In addition, T1 signal intensities of a perilesional edema were quantitatively analyzed. In cavernous angiomas, volumes of hemorrhagic lesions and perilesional edemas, lesion locations, presence of contrast enhancement, and time intervals between symptom onset and MR imaging were also assessed. Data were analyzed using unpaired t test or Fisher exact test.

RESULTS

T1 hyperintense perilesional signal intensity sign was found in 18 (62.1%) of 29 cavernous angiomas, in 1 (6.3%) of 16 metastases, and in 0 primary brain tumors or intracerebral hemorrhages. Sensitivity, specificity, and positive predictive value of this sign for cavernous angioma were 62%, 98%, and 95%, respectively. The perilesional T1 hyperintensity was significantly higher in cavernous angiomas (P = .045) than in normal white matter. Perilesional edema volumes were larger in cavernous angiomas with the MR sign than in cavernous angiomas without the sign (P = .009).

CONCLUSION

When the MR sign of T1 hyperintense perilesional signal intensity is present, there is a high probability of cavernous angioma being present in the brain, and this MR sign may be helpful for differentiating cavernous angioma from hemorrhagic tumors and intracerebral hemorrhages.

Giant cavernous hemangiomas: report of three cases

Giant cavernous hemangiomas occur very rarely, and little has been reported about their behavior. In this case report three cavernous hemangiomas with a diametric measure between 6 cm and 7 cm and distinct features will be described. A 36-year-old female patient presented with headache and nausea. A CT scan disclosed a large circumscribed tumor with strong contrast enhancement in the temporo-parieto-occipital region of the right cerebral hemisphere and extension into the right cerebellar hemisphere. A 35-year-old woman was admitted to our emergency ward with a generalized seizure and a dilated pupil. The CT scan showed an extensive left frontal lesion containing a substantial hyperintense part, suspicious for hemorrhage. A 3-year-old girl was admitted with generalized seizure and progressively declining consciousness. A large left frontotemporal paraventricular multi-cystic lesion was encountered on the CT scan. All three patients were operated on. Two recovered very well. In the case of the 3-year-old girl stable disease was reached. Giant cavernomas do not differ from average-sized cavernomas in clinical, surgical or histopathological presentation but may differ radiologically. However, the possible diagnosis of cavernoma can be overlooked, due to their size and possible differential diagnosis.

Gamma knife surgery of brain cavernous hemangiomas

Object.The authors conducted a study to record more detailed information about the natural course and factors predictive of outcome following gamma knife surgery (GKS) for cavernous hemangiomas.

Methods.One hundred twelve patients with brain cavernous hemangiomas underwent GKS between 1993 and 2000. The median prescription dose was 16 Gy. One hundred seven patients were followed for a median of 48 months (range 6–114 months). The rebleeding rate was 1.6%, which is not significantly different with that prior to radiosurgery (2%). An increase in volume was observed in 1.8% of cases and a decrease in 45%. Perilesional edema was detected in 27% of patients, which, together with the rebleeding, caused a transient morbidity rate of 20.5% and permanent morbidity rate of 4.5%. Before radiosurgery 39% of patients suffered from epilepsy and this improved in 45% of them. Two patients with brainstem cavernous hemangiomas died due to rebleeding. Rebleeding was more frequent in female middle-aged patients with a history of bleeding, a larger lesion volume, and a prescription dose below 13 Gy. Edema after GKS occurred more frequently in patients who had surgery, a larger lesion volume, and in those in whom the prescription dose was more than 13 Gy.

Conclusions.Gamma knife surgery of cavernous hemangiomas can produce an acceptable rate of morbidity, which can be reduced by using a lower margin dose. Lesion regression was observed in many patients. Radiosurgery seems to remain a suitable treatment modality in carefully selected patients.

Gamma knife surgery of brain cavernous hemangiomas

Object. The authors conducted a study to record more detailed information about the natural course and factors predictive of outcome following gamma knife surgery (GKS) for cavernous hemangiomas.

Methods. One hundred twelve patients with brain cavernous hemangiomas underwent GKS between 1993 and 2000. The median prescription dose was 16 Gy. One hundred seven patients were followed for a median of 48 months (range 6–114 months). The rebleeding rate was 1.6%, which is not significantly different with that prior to radiosurgery (2%). An increase in volume was observed in 1.8% of cases and a decrease in 45%. Perilesional edema was detected in 27% of patients, which, together with the rebleeding, caused a transient morbidity rate of 20.5% and permanent morbidity rate of 4.5%. Before radiosurgery 39% of patients suffered from epilepsy and this improved in 45% of them. Two patients with brainstem cavernous hemangiomas died due to rebleeding. Rebleeding was more frequent in female middle-aged patients with a history of bleeding, a larger lesion volume, and a prescription dose below 13 Gy. Edema after GKS occurred more frequently in patients who had surgery, a larger lesion volume, and in those in whom the prescription dose was more than 13 Gy.

Conclusions. Gamma knife surgery of cavernous hemangiomas can produce an acceptable rate of morbidity, which can be reduced by using a lower margin dose. Lesion regression was observed in many patients. Radiosurgery seems to remain a suitable treatment modality in carefully selected patients.

Multiple cavernomas of brain presenting with simultaneous hemorrhage in two lesions: a case report

BACKGROUND

Cavernomas are rare vascular lesions of the brain that can bleed. However, the risk of bleeding is lower than that of aneurysms or arteriovenous malformations. In selected cases, bleeding cavernomas require surgical management. Presented here is a case of multiple cavernomas of the brain with simultaneous bleeding in two different lesions, along with its management. Although multiple cavernomas have been described in the literature, simultaneous bleeding in two different lesions is rare.

CASE DESCRIPTION

A 52-year-old woman presented with difficulty maintaining balance, double vision, and slurred speech. She had had multiple surgeries for cavernous angioma of the brain in the past. Examination and investigations revealed two cavernomas, one in the dorsal midbrain region and one in the left occipital region. Her clinical condition deteriorated suddenly, and further evaluation revealed bleeding in both the cavernomas. The lesion in the midbrain was removed surgically. Since the lesion was in the posterior midbrain, a posterior interhemispheric approach was used with the help of frameless stereotactic navigation. Total excision was achieved. The lesion in the occipital lobe was not operated on. The patient had an uneventful recovery. It was planned to observe the progress of the occipital cavernoma by serial magnetic resonance imaging scans.

CONCLUSION

Although there may be simultaneous bleeding in two or even more lesions, surgical treatment should be undertaken for the lesions jeopardizing critical structures or exerting mass effects. Additionally, it was discovered that frameless stereotactic navigation was of immense help in delineating the lesion and for safe excision of the lesion in critical areas.

Follow-up of 13 patients with surgical treatment of cerebral cavernous malformations: effect on epilepsy and patient disability

OBJECTIVE

We report a series of 13 patients with surgical treatment of cerebral cavernous malformation (CM). The aim of this study was to investigate postoperative patient disability and seizure control in patients with CM in order to clarify indications for neurosurgical removal. In our series we emphasize the beneficial effect of excision of CMs. We also give an overview of the current literature covering options for treatment in surgically inaccessible CMs.

METHODS

In this retrospective study we describe the clinical outcomes of neurosurgical intervention in 13 patients with a CM. Seven patients had epilepsy at presentation and six had focal neurological deficits due to intracerebral haemorrhage (five patients) or mass effect due to the CM (one patient). The modified Rankin scale was used to define patient disability pre- and postoperatively. An overview of the indications for surgery and postoperative outcome with follow up periods of 1-6 years (mean: 3.3 years) are provided.

RESULTS

In all patients presenting with epilepsy a reduction in seizure frequency was seen. Four of them became seizure-free postoperatively. The six patients with neurological deficits due to intracerebral haemorrhage or mass effect due to the CM showed clinical improvement postoperatively, two of them made full recoveries. Improvement of the postoperative Rankin score was seen in six of 13 patients.

CONCLUSION

Improvement in seizure control and reduction in patient disability warrants surgical intervention in symptomatic CMs.

Temporal clustering of hemorrhages from untreated cavernous malformations of the central nervous system

OBJECTIVE

Hemorrhages from cerebral cavernous malformations (CMs) sometimes seem to occur in closely spaced "clusters" interspersed with long hemorrhage-free intervals. Clustering of hemorrhages could affect retrospective assessments of radiosurgery efficacy in prevention of CM rehemorrhage. However, this empirical observation had not been tested quantitatively. To test whether CM hemorrhages tend to cluster, we reviewed pretreatment rebleeding rates after a first symptomatic hemorrhage in CM patients who later underwent surgery or radiosurgery.

METHODS

We performed a retrospective review of 141 patients with CMs who presented with clinically overt hemorrhage, and who subsequently underwent surgery or proton beam radiosurgery during an 18-year period. Statistical models were used to analyze all events per person and identify potential variation in rebleeding risk with time after a previous hemorrhage.

RESULTS

Sixty-three of 141 patients experienced a second hemorrhage before treatment; 16 had additional hemorrhages. Five hundred thirty-eight patient years elapsed between first hemorrhages and treatment. The cumulative incidence of a second hemorrhage after the first CM hemorrhage was 14% after 1 year and 56% after 5 years. During the first 2.5 years after a hemorrhage, the monthly rehemorrhage hazard was 2%. The risk then decreased spontaneously to less than 1% per month, which represents a 2.4-fold decline (P < 0.001). Rehemorrhage rates were higher in younger patients (P < 0.01), but not in females or in patients with deep lesions. Shorter intervals between successive hemorrhages did not predict higher subsequent rehemorrhage risk.

CONCLUSION

The rehemorrhage rate from untreated CMs is high initially, and it decreases 2 to 3 years after a previous hemorrhage. This hazard pattern generates the observed temporal clustering of hemorrhages from untreated CMs.

Pineal region cavernoma--case report

A 45-year-old male presented with a rare pineal region cavernoma. Magnetic resonance (MR) imaging confirmed the preoperative diagnosis. The tumor was totally excised. The patient was subsequently cured. Analysis of 15 reported cases found a slight female preponderance. The second and third decades were the most common age group. The course of pineal cavernomas can be complicated by hemorrhage, occlusion of cerebrospinal fluid pathways, and focal neurological and neuroendocrine symptoms but no specific clinical features. However, MR imaging has high sensitivity and the specificity for the diagnosis of pineal cavernoma. Total microneurosurgical excision is the treatment of choice, and patients had an excellent outcome. Stereotactic biopsy can be potentially dangerous because of the risk of hemorrhage. The use of radiosurgery requires evaluation of long-term risks and safe dose levels. Total excision of the pineal cavernoma using microsurgical techniques is the choice of treatment in young and healthy patients since there is an increased risk of recurrent hemorrhage and progressive neurological decline. A conservative approach is preferred in older patients.

Utility of magnetic resonance imaging in acute intracerebral hemorrhage

The authors determine whether magnetic resonance imaging (MRI) during acute hospitalization for spontaneous intracerebral hemorrhage (ICH) provides new diagnostic information. ICD-9 codes were used to identify consecutive patients with spontaneous ICH at Hermann Hospital, Houston, Texas, between January 1995 and August, 1997. Two investigators employed rigorous criteria to determine whether the MRI findings led to a specific new diagnosis. Two hundred ninety-one patients met inclusion and exclusion criteria. Sixty-seven (23%) patients underwent brain MRI during the acute hospitalization. MRI provided a new diagnosis in 15 of these 67 patients (22%). Amyloid angiopathy and vascular malformation (four each) were the most frequently identified etiologies. The yield of MRI was low in basal ganglia and thalamic hemorrhage. Two of 23 (9%) patients with deep ICH and 13 of 44 (30%) patients with lobar and infratentorial hemorrhage had etiology determined by MRI. Timing of MRI did not affect yield.

[Stereotactic-guided surgery for cavernous angiomas]

Intracerebral cavernous angiomas may cause hemorrhage, epileptic seizures and neurological deficits. The diagnosis of these lesions became easier with the advent of the magnetic resonance image (MRI). Radical resection is the treatment of choice. Due to frequent subcortical or deep location, image-guided techniques, such as stereotactic-guided surgery, offer many advantages as smaller skin incision and craniotomy, less brain manipulation with consequently lower morbidity. We present a series of nine cavernous angiomas treated by stereotactic-guided radical surgical resection. The diagnosis was done by MRI and confirmed by pathologic studies in all cases. Mean age of patients was 30 years old (range 20-54 years). Postoperative morbidity occurred in two cases: one patient had a convulsion on the third postoperative day and the other presented dysphasia and hemiparesis on the second postoperative day, both with total recovery. Total resection of the lesion was possible in all cases with no neurological deficit.

Intraoperative direct subcortical stimulation for identification of the internal capsule, combined with an image-guided stereotactic system during surgery for basal ganglia lesions

BACKGROUND

The two main problems of surgery for basal ganglia lesions are: first, the difficulty of accurately localizing the lesion in this deep location; and second, the proximity to the internal capsule, with the risk of permanent postoperative sequelae. The author describes the use of intraoperative direct electrical subcortical stimulation in the identification and preservation of the internal capsule, combined with an image-guided stereotactic system for the selection of the best surgical approach in a case of deep cavernoma.

CASE DESCRIPTION

A 33-year-old man was admitted to our institution with a history of three episodes of transitory left hemiparesia in the last 12 years. Neurological examination revealed a mild left weakness. Magnetic resonance imaging (MRI) showed typical features of a right posterior capsular-lentiform cavernoma. To prevent another hemorrhagic event, surgery was performed via a right transdistal sylvian approach, using a computer-assisted stereotactic method that allowed us to reach the lesion directly and direct stimulations to detect the subcortical pyramidal pathways. The patient had a transitory worsening with complete recovery in 10 days. Control MRI showed total resection.

CONCLUSION

As described at the cortical level, the intraoperative direct subcortical stimulations seem also to represent an easy, safe, accurate, and reliable method of real-time functional identification of the internal capsule during surgery for basal ganglia lesions. The combination with an image-guided stereotactic system to accurately localize the lesion minimizes the risk of postoperative sequelae, and seems to warrant an increase of the surgical indications in this location.