CCM3 Loss-Induced Lymphatic Defect Is Mediated by the Augmented VEGFR3-ERK1/2 Signaling

OBJECTIVE

Cerebral cavernous malformations (CCMs) can happen anywhere in the body, although they most commonly produce symptoms in the brain. The role of CCM genes in other vascular beds outside the brain and retina is not well-examined, although the 3 CCM-associated genes (CCM1, CCM2, and CCM3) are ubiquitously expressed in all tissues. We aimed to determine the role of CCM gene in lymphatics. Approach and Results: Mice with an inducible pan-endothelial cell (EC) or lymphatic EC deletion of Ccm3 (Pdcd10ECKO or Pdcd10LECKO) exhibit dilated lymphatic capillaries and collecting vessels with abnormal valve structure. Morphological alterations were correlated with lymphatic dysfunction in Pdcd10LECKO mice as determined by Evans blue dye and fluorescein isothiocyanate(FITC)-dextran transport assays. Pdcd10LECKO lymphatics had increased VEGFR3 (vascular endothelial growth factor receptor-3)-ERK1/2 (extracellular signal-regulated kinase 1/2) signaling with lymphatic hyperplasia. Mechanistic studies suggested that VEGFR3 is primarily regulated at a transcriptional level in Ccm3-deficient lymphatic ECs, in an NF-κB (nuclear factor κB)-dependent manner. CCM3 binds to importin alpha 2/KPNA2 (karyopherin subunit alpha 2), and a CCM3 deletion releases KPNA2 to activate NF-κB P65 by facilitating its nuclear translocation and P65-dependent VEGFR3 transcription. Moreover, increased VEGFR3 in lymphatic EC preferentially activates ERK1/2 signaling, which is critical for lymphatic EC proliferation. Importantly, inhibition of VEGFR3 or ERK1/2 rescued the lymphatic defects in structure and function.

CONCLUSIONS

Our data demonstrate that CCM3 deletion augments the VEGFR3-ERK1/2 signaling in lymphatic EC that drives lymphatic hyperplasia and malformation and warrant further investigation on the potential clinical relevance of lymphatic dysfunction in patients with CCM.

Mapping endothelial-cell diversity in cerebral cavernous malformations at single-cell resolution

Cerebral cavernous malformation (CCM) is a rare neurovascular disease that is characterized by enlarged and irregular blood vessels that often lead to cerebral hemorrhage. Loss-of-function mutations to any of three genes results in CCM lesion formation; namely, KRIT1, CCM2, and PDCD10 (CCM3). Here, we report for the first time in-depth single-cell RNA sequencing, combined with spatial transcriptomics and immunohistochemistry, to comprehensively characterize subclasses of brain endothelial cells (ECs) under both normal conditions and after deletion of Pdcd10 (Ccm3) in a mouse model of CCM. Integrated single-cell analysis identifies arterial ECs as refractory to CCM transformation. Conversely, a subset of angiogenic venous capillary ECs and respective resident endothelial progenitors appear to be at the origin of CCM lesions. These data are relevant for the understanding of the plasticity of the brain vascular system and provide novel insights into the molecular basis of CCM disease at the single cell level.

Oxidative stress and inflammation in cerebral cavernous malformation disease pathogenesis: Two sides of the same coin

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CCM proteins play pleiotropic roles in various redox-sensitive signaling pathways.

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CCM proteins modulate the crosstalk between redox signaling and autophagy that govern cell homeostasis and stress responses.

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Oxidative stress and inflammation are emerging as key focal determinants of CCM lesion formation, progression and severity.

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The pleiotropic functions of CCM proteins may prevent vascular dysfunctions triggered by local oxidative stress and inflammatory events.

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The distinct therapeutic compounds proposed so far for CCM disease share the ability to modulate redox signaling and autophagy.

Cerebral Cavernous Malformation (CCM) is a vascular disease of proven genetic origin, which may arise sporadically or is inherited as an autosomal dominant condition with incomplete penetrance and highly variable expressivity. CCM lesions exhibit a range of different phenotypes, including wide inter-individual differences in lesion number, size, and susceptibility to intracerebral hemorrhage (ICH). Lesions may remain asymptomatic or result in pathological conditions of various type and severity at any age, with symptoms ranging from recurrent headaches to severe neurological deficits, seizures, and stroke. To date there are no direct therapeutic approaches for CCM disease besides the surgical removal of accessible lesions. Novel pharmacological strategies are particularly needed to limit disease progression and severity and prevent de novo formation of CCM lesions in susceptible individuals.

Useful insights into innovative approaches for CCM disease prevention and treatment are emerging from a growing understanding of the biological functions of the three known CCM proteins, CCM1/KRIT1, CCM2 and CCM3/PDCD10. In particular, accumulating evidence indicates that these proteins play major roles in distinct signaling pathways, including those involved in cellular responses to oxidative stress, inflammation and angiogenesis, pointing to pathophysiological mechanisms whereby the function of CCM proteins may be relevant in preventing vascular dysfunctions triggered by these events. Indeed, emerging findings demonstrate that the pleiotropic roles of CCM proteins reflect their critical capacity to modulate the fine-tuned crosstalk between redox signaling and autophagy that govern cell homeostasis and stress responses, providing a novel mechanistic scenario that reconciles both the multiple signaling pathways linked to CCM proteins and the distinct therapeutic approaches proposed so far. In addition, recent studies in CCM patient cohorts suggest that genetic susceptibility factors related to differences in vascular sensitivity to oxidative stress and inflammation contribute to inter-individual differences in CCM disease susceptibility and severity.

This review discusses recent progress into the understanding of the molecular basis and mechanisms of CCM disease pathogenesis, with specific emphasis on the potential contribution of altered cell responses to oxidative stress and inflammatory events occurring locally in the microvascular environment, and consequent implications for the development of novel, safe, and effective preventive and therapeutic strategies.

The Role of Hemosiderin Excision in Seizure Outcome in Cerebral Cavernous Malformation Surgery: A Systematic Review and Meta-Analysis

Background and Purpose

Whether the excision of hemosiderin surrounding cerebral cavernous malformations (CCMs) is necessary to achieve a seizure-free result has been the subject of debate. Here, we report a systematic review of related literature up to Jan 1, 2015 including 594 patients to assess the effect of hemosiderin excision on seizure outcome in patients with CCMs by meta-analysis.

Methods

Ten studies comparing extended hemosiderin excision with only lesion resection were identified by searching the English-language literature. Meta-analyses, subgroup analyses and sensitivity analysis were conducted to determine the association between hemosiderin excision and seizure outcome after surgery.

Results

Seizure outcome was significantly improved in the patients who underwent an extended excision of the surrounding hemosiderin (OR, 0.62; 95% CI: 0.42–0.91; P = 0.01). In subgroup analysis, studies from Asia (OR, 0.42; 95% CI: 0.25–0.71; P = 0.001), male-majority (female ratio < 50%) studies (OR, 0.56; 95% CI: 0.33–0.96; P = 0.04), low occurrence rate of multiple CCMs (OR, 0.37; 95% CI: 0.20–0.71; P = 0.003), cohort studies (OR, 0.44; 95% CI: 0.28–0.68; P = 0.78), longer duration of seizure symptoms (> 1 year) before surgery (OR, 0.43; 95% CI: 0.22–0.84; P = 0.01), lesion diameter > 2 cm (OR, 0.41; 95% CI: 0.19–0.87; P = 0.02) and short-term (< 3 years) follow-up (OR, 0.48; 95% CI: 0.29–0.80; P = 0.005) tended to correlate with a significantly favorable outcome.

Conclusion

Patients who underwent extended surrounding hemosiderin excision could exhibit significantly improved seizure outcomes compared to patients without hemosiderin excision. However, further well-designed prospective multiple-center RCT studies are still needed.

Cerebral cavernous malformations in the setting of focal epilepsies: pathological findings, clinical characteristics, and surgical treatment principles

Cavernous cerebral malformations (CCMs) are a well-defined epilepsy-associated pathology. They represent lesions/conglomerates of abnormally configured vessels leading to seizures either as a result of physiological changes affecting the cerebral cortex immediately surrounding the CCM (an epileptogenic mechanism that is relevant for both temporal and extratemporal lesions), or as a result of promoting epileptogenicity in remote but anatomo-functionally connected brain regions (a mechanism that is particularly relevant for temporal lobe lesions). This review details the pathological findings in CCMs and discusses the mechanisms of epileptogenicity in this context. The bulk of the review will focus on therapeutic strategies. Medical therapy using antiepileptic drugs is recommended as a first-line therapy, but surgical removal of the CCM with the surrounding cortex should be pursued if seizures prove to be drug resistant. Early timing of the resection and complete removal of any associated epileptic pathology are critical for best outcomes. In addition to reviewing the available data from prior series, we present original research from two specialized epilepsy centers targeted at answering particularly pressing clinical questions mainly related to the ideal timing and extent of surgery. Further research is needed to define the best surgical strategies in patients with temporal lobe CCMs and structurally normal hippocampi.

The clinical features and surgical outcomes of patients with intramedullary spinal cord cavernous malformations

BACKGROUND

Cavernous malformations (CMs) are not uncommon, but most of them are found to be located intracranially. Intramedullary CMs are rare, accounting for only 3-5% of identified total central nervous system lesions. The natural history of intramedullary CMs and their clinical features, including the risk of hemorrhage from a large series, still remains unclear and needs to be elucidated. We review our experience with surgically treated patients with intramedullary CMs and discuss the clinical features and surgical outcomes.

METHODS

Between March 2004 and March 2010, a total of 21 patients with intramedullary spinal cord CMs were surgically treated in a single institution. Data from 21 patients were retrospectively analyzed.

RESULTS

There were 13 females and 8 males ranging in age from 10 to 70 years (mean age 39.3 years). All patients harbored single symptomatic CM of the nervous system, and multiple lesions were not found. The annual retrospective hemorrhage rate was 2.18% per patient/year. All but one CM were completely resected, and the average follow-up period was 22.1 months (1-73 months). Ten of the 21 patients experienced an improvement in neurological state, 9 patients remained unchanged, and 2 patients experienced worsening of their conditions.

CONCLUSIONS

Symptomatic intramedullary CMs should be surgically removed to avoid further neurological deterioration. Though there are some limitations due to the retrospective nature of this study and its small number of patients, the prognosis was found to be related to the preoperative neurological state and to the type of symptom presentation.

[Clinical features and management of cavernous and venous angiomas in the head]

Cerebral cavernous angiomas consist of well-circumscribed collections of thin-walled sinusoidal vascular channels lacking the intervening brain tissue. They are present in 0.4-0.8% of the population, and can occur in a sporadic or familial form. Most common symptoms are seizures, hemorrhage, and focal neurological deficits. The annual bleeding rate of the patient is reported to be 0.25%-20%. High-resolution magnetic resonance imaging (MRI) is a useful diagnostic tool with a high degree of sensitivity and specificity. Microsurgical excision of the lesion is a good treatment choice for cavernous angiomas in the brain, even in the brainstem. Although stereotactic radiosurgery may reduce the incidence of rebleeding and the frequency of seizures, its indication should be carefully investigated because of the relatively high rate of radiation-induced side effects. Less frequently, cavernous angiomas can be located at the extra-axial regions of the head, which include the cavernous sinus, the orbit, and the cranial nerves. Cavernous angiomas in the cavernous sinus pose a neurosurgical challenge due to the high vascularity and involvement of the neurovascular structures, and stereotactic radiosurgery is considered as an additional option. Surgical resection is recommended for symptomatic cavernous angiomas in the orbit; however, the rate of complications after resection is not necessarily low for cavernous angiomas within the apex. Venous angiomas are anomalies of normal venous drainage, which show characteristic appearance of the drainage system in the late phase of angiography (caput medusae). They are found either alone or in combination with other vascular malformations. Conservative treatment is recommended except for patients with a large hematoma or with a coexisting cavernous angioma.

Anterior transpetrosal and subtemporal transtentorial approaches for pontine cavernomas

OBJECTIVE

Pontine cavernomas are benign vascular lesions whose surgical treatment is challenging due to their localization. We report our experience in the surgical management of these lesions exclusively using a lateral, subtemporal transtentorial approach in high pontine lesions and an anterior petrosal approach in low pontine lesions.

METHODS

We performed a retrospective study on a series of patients who were operated on for a pontine cavernoma in our neurosurgery department between 1987 and 2007. In the study, we detail the patients' clinical and preoperative radiological data and compare the two surgical techniques we used. Finally, we analyze the postoperative follow-up, the morbidity encountered according to the surgical approach used, and the long-term outcomes.

RESULTS

We enrolled nine patients into the study. Six patients were operated on using an anterior petrosal approach. None of the patients died. Five patients were able to resume their former professional activity after surgery and were clearly improved following surgery. One patient was worse after surgery (hemiplegia and deafness). We used a subtemporal transtentorial approach in three of the patients. None of the patients died. Two of the patients were able to resume their prior professional activities without any sequels, and the third patient's condition worsened following surgery (temporal hematoma).

CONCLUSION

The lateral surgical approach for pontine cavernomas constitutes a reasonable surgical alternative to the transventricular, suboccipital, retromastoid, or transclival approaches. Patient morbidity in both approaches is acceptable, and the long-term outcome is satisfactory with respect to sequels and the resumption of prior professional activity.

Trigonal cavernous angioma: a short illustrated review

PURPOSE

Intraventricular cavernomas are rare. Even more rare are those presenting in the trigone of the lateral ventricles.

METHODS

We performed a search of the literature of the last 30 years and identified all cases of intraventricular cavernous angiomas. Trigonal cavernomas were separately identified and analysed. Our search yielded a total of 13 trigonal cavernomas.

RESULTS

Of a total of 61 intraventricular cases, 13 were located in the trigone of the lateral ventricles. The most prominent presenting symptom was intracranial hypertension (68.9%), followed by seizures (18.2%) and hemorrhage (13.1%).The literature review revealed a trend of intraventricular cavernomas to present with intracranial hypertension rather than seizures or focal neurologic deficit, unlike their intraparenchymal counterparts. We feel that this difference has received little attention in the international literature. We discuss a possible pathogenetic mechanism for the presence of intracranial hypertension and address different aspects of diagnosis and treatment of this benign lesion.

CONCLUSIONS

Trigonal cavernomas are benign lesions that have an excellent outcome after radical excision. Symptoms and signs of intracranial hypertension and hydrocephalus may be the prominent initial presentation of this rare ailment.

[Clinical-neuropsychological study of patients with hematomas, cavernomas and arteriovenous malformations of the brain stem]

A clinical-neuropsychological study of 25 patients with hematomas, cavernomas and arteriovenous malformations of different brain stem regions has been performed. Patients with hydrocephalic-hypertensive and dislocation syndromes as well as a history of neurological diseases were excluded from the study. All patients had hemorrhages in different brain stem regions, most of which had occurred several weeks ago. Hematomas were located in different regions of the pons (14 patients) and midbrain (7 patients) and spread to both regions in 4 patients. All patients underwent MRI study of the brain and complex neuropsychological investigation using the A.R. Luria's method. Neuropsychological symptoms before the surgery were found in 20 patients. Cognitive disturbances similar by the lesion of frontal lobes, in particular the promoter zone, that manifested themselves in disturbances of dynamic praxis, writing, verbal memory, were observed most often. Cognitive disturbances similar by the lesion of occipital hemisphere regions, i.e. disturbances of visual gnosis and spatial defects, were found less often. The most severe symptoms were observed in the lesion of the midbrain and upper regions of the pons.

[Cerebral cavernous malformation--its genetic and biological background]

Cerebral cavernous malformations (CCMs) are vascular lesions of the central nervous system that consisit of enlarged vascular channels without intervening normal parenchyma. The CCMs can occur as sporadic or autosomal-dominant inherited condition. Linkage analysis of the familial CCMs has identified three different loci at 7q21.2 (CCM1), 7q13 (CCM2), and 3q25.2-q27 (CCM3). The genes at these loci have been identified as Krev1 Interaction Trapped 1; KRIT1 (CCM1), MGC4607; malcavernin (CCM2), and PDCD10 (CCM3), respectively. Recent investigations on these genes suggest that there are interactions between each gene, although the exact pathway of the formation of CCMs is still undetermined. In this review, the authors summarize the currently avaliable knowledge on the molecular events associated with CCMs.

Nitric oxide synthase and NMDA receptor expressions in cavernoma tissues with epileptogenesis

OBJECTIVES

To investigate the contribution of nitric oxide (NO) and the glutamate systems to epileptogenicity of cavernoma (CA).

METHODS

Using immunohistochemistry we examined NO synthases (NOS; neuronal, inducible and endothelial) and N-methyl-D-aspartate (NMDA) receptor subunits 1(NR1) and 2A/B (NR2A/B) in tissues, with and without hemosiderin deposits, adjacent to CA resected from temporal (seven patients) and frontal (one patient) lobes.

RESULTS

All isoforms of NOS, especially iNOS expression, was significantly upregulated in company with NR2A/B expression, not only in declining neuronal cells but also in reactive astrocytes in the tissue, with hemosiderin deposits, adjacent to CA and moreover the degree of iNOS expression was significantly correlated with seizure frequency.

CONCLUSIONS

These preliminary results sustain a speculation that excessive NO may generate in the tissue surrounding CA with repeated microhaemorrhaging and seizures. The neuronal loss and reactive glial proliferation induced by iron or NO may play a role in epileptogenesis.

Anorexia nervosa associated with right frontal brain lesion

OBJECTIVE

A causal association of brain lesion to the physiopathology of anorexia nervosa will be discussed.

METHOD

The authors report the case of a female patient who developed anorexia nervosa. A cavernoma, located on the frontal side of the right sylvian, was discovered by chance after a seizure.

RESULTS

Surgical treatment of the lesion resulted in complete remission of the eating disorder at two years follow-up.

CONCLUSION

Evidence for organic brain contribution to anorexia nervosa is strong and can be illustrated by this case report of anorexia nervosa associated with cerebral tumour.

Identification of an Arg35X mutation in the PDCD10 gene in a patient with cerebral and multiple spinal cavernous malformations

Although cerebral cavernous malformations (CCMs) are not uncommon, the concurrent finding of cavernous malformations (CMs) both in the brain and spinal cord is quite rare. Furthermore, multiple spinal cord CMs are extremely rare with only a few cases being reported thus far. Recently, we encountered a 33-year-old Korean male with both CCM and multiple spinal intramedullary CMs. The patient complained of seizure and right chest paresthesia. The lesions were located throughout the neuraxis including the cerebral hemisphere, brain stem, and cervical and thoracic spinal cords. Molecular analysis of the KRIT1 (CCM1), CCM2, and PDCD10 (CCM3) genes identified a heterozygous nonsense mutation (c.103C>T; Arg35X) in the PDCD10 gene, which was reported previously in a CCM family. The patient denied a family history, however, his daughter had an identical mutation, but was asymptomatic. Three months later, after identifying the mutation in the father and the daughter, the daughter presented with seizure. To the best of our knowledge, this is the first report of an association between a mutation in the PDCD10 gene and spinal CMs.

Electrocorticography discharge patterns in patients with a cavernous hemangioma and pharmacoresistent epilepsy

OBJECT

Neurodevelopmental lesions (NDLs) such as glioneuronal tumors and cortical dysplasia produce characteristic electrocorticography (ECoG) discharge patterns. Because cavernomas, another congenital abnormality, are also associated with pharmacoresistant epilepsy, the authors wondered whether they exhibit discharge patterns similar to those occurring in NDLs.

METHODS

Intraoperative ECoG recordings from 19 patients with cavernomas and 54 with NDLs were reviewed for continuous spikes, bursts, or recruiting discharges and to determine whether these patterns were spatially coincident with the lesion. Relative densities of microglia and the intensity of Fe3+ staining in surgical samples were evaluated. Seizure outcome was assessed 1 year after surgery.

RESULTS

The mean ages at seizure onset and surgery were higher in patients in the cavernoma group than in the NDL group (22.5 and 36.4 years compared with 10.0 and 25.2 years, respectively). Neocortical discharge patterns occurred equally in patients with either cavernomas (53%) or NDLs (41%). In the mesiotemporal area coincident bursts occurred more often in patients with cavernomas than patients with NDLs (55% compared with 10%, respectively). Coincident continuous spiking was associated with a longer duration of epilepsy in patients with cavernomas (23.5 years compared with 11.4 years for those without coincident continuous spiking) and with a lower age at seizure onset in those with NDLs (4.1 years compared with 11.8 years for those without coincident continuous spiking). In the cavernoma group the absence of coincident bursts was associated with high microglia density. There were no associations between the intensity of Fe3+ staining and discharge patterns, although the discharge patterns were associated with a worse outcome in patients with NDLs.

CONCLUSIONS

In patients with NDLs, continuous spiking patterns may be markers of a widespread epileptogenic zone due to an early insult to the developing brain; in patients with cavernomas, such patterns may indicate secondary epileptogenesis. Microglia may inhibit discharge patterns in patients with cavernomas.

Parenchymal abnormalities associated with developmental venous anomalies

INTRODUCTION

To report a retrospective series of 84 cerebral developmental venous anomalies (DVAs), focusing on associated parenchymal abnormalities within the drainage territory of the DVA.

METHODS

DVAs were identified during routine diagnostic radiological work-up based on magnetic resonance imaging (MRI) (60 cases), computed tomography (CT) (62 cases) or both (36 cases). Regional parenchymal modifications within the drainage territory of the DVA, such as cortical or subcortical atrophy, white matter density or signal alterations, dystrophic calcifications, presence of haemorrhage or a cavernous-like vascular malformation (CVM), were noted. A stenosis of the collecting vein of the DVA was also sought for.

RESULTS

Brain abnormalities within the drainage territory of a DVA were encountered in 65.4% of the cases. Locoregional brain atrophy occurred in 29.7% of the cases, followed by white matter lesions in 28.3% of MRI investigations and 19.3% of CT investigations, CVMs in 13.3% of MRI investigations and dystrophic calcification in 9.6% of CT investigations. An intracranial haemorrhage possibly related to a DVA occurred in 2.4% cases, and a stenosis on the collecting vein was documented in 13.1% of cases. Parenchymal abnormalities were identified for all DVA sizes.

CONCLUSION

Brain parenchymal abnormalities were associated with DVAs in close to two thirds of the cases evaluated. These abnormalities are thought to occur secondarily, likely during post-natal life, as a result of chronic venous hypertension. Outflow obstruction, progressive thickening of the walls of the DVA and their morphological organization into a venous convergence zone are thought to contribute to the development of venous hypertension in DVA.

Intraneural cavernous malformation of the cauda equina

Spinal cavernous angiomas are rare vascular malformations occurring mainly in the vertebral body with or without an extradural extension. Only 3-5% of these lesions are entirely located in the spinal canal where they can occupy an extradural, intradural-extramedullary or intramedullary position. We present a 75-year-old woman with signs and symptoms of multiple lumbar radiculopathy. The lumbosacral MRI showed an intradural cauda equina lesion with heterogeneous contrast enhancement that was subsequently radically removed through an L3-L4 laminectomy. The microscopic appearance was suggestive of cavernous angioma with intraneural growth. Clinical, radiological, and surgical features of this unusual lesion (to date, only 12 cases are reported) are discussed.

Critically Located Cavernous Malformations

INTRODUCTION

The aim of this study was to evaluate the clinical results of patients who underwent resection with the aid of microsurgical techniques and stereotactic and image-guided surgery for critically located cavernous malformations which still represent a considerable surgical challenge due to the close proximity of vital and eloquent structures.

METHODS

Between 1997 and 2003, 12 patients with critically located cavernous malformations (CMs) underwent surgical resections at Ankara University Hospital. CMs of the pons (n=3), medulla oblongata (n=1), cavernous sinus (n=3), motor cortex (n=4) and the newly defined superior cerebellar peduncle (n=1) were treated using image-guidance and advanced microsurgical principles. Preoperative assessment was done with CT, MRI and angiography. Lesion locations, clinical presentations and outcome were analyzed. The surgical approach was chosen as lateral suboccipital (n=4), parietal (n=4), cranio-orbitozygomatic (n=3) and retrosigmoid (n=1).

RESULTS

All CMs were readily identified and completely removed with no permanent morbidity and mortality. The immediate outcome after surgery was improved for 8 patients (66.6%). Long-term outcome was unchanged for one patient and a proved good surgical outcome for three patients, during the mean follow-up period.

DISCUSSION

Stereotactic methods together with image-guidance and microsurgical techniques allow the creation of most effective and safe corridors to access the CMs in eloquent regions with a minimization of tissue manipulation and low risk of permanent neurological deficit.

Morphological Observation and In Vitro Angiogenesis Assay of Endothelial Cells Isolated From Human Cerebral Cavernous Malformations

BACKGROUND AND PURPOSE

Little is known about the role of endothelial cells (ECs) in the pathogenesis of cerebral cavernous malformation because of the difficulties to obtain highly pure ECs. Thus, this study attempted to establish a reliable procedure to isolate and culture ECs from human cerebral cavernous malformation lesions. The biological features and the angiogenic potential of the cultured ECs were also investigated.

METHODS

A modified protocol was developed to isolate and culture cerebral cavernous malformation endothelial cells (CECs)from surgically resected human specimens. The biological features of CECs were investigated by electron microscope, immunostaining, real-time polymerase chain reaction, fluorescence-activated cell sorter, and Western blotting. The tube formation by CECs was examined in an in vitro angiogenesis model with or without the addition of vascular endothelial growth factor.

RESULTS

CECs from the specimens unaffected by the intraoperative bipolar coagulation were cultivated successfully with higher than 95% purity. Comparing to the ECs from control brain tissue, CECs presented primitive nucleus in ultrathin section, expressed higher levels of vascular endothelial growth factor receptor-1 and vascular endothelial growth factor receptor-2, and spontaneously formed tube structures in a 3-dimensional collagen matrix. The tube formation by CECs was significantly promoted by vascular endothelial growth factor treatment.

CONCLUSIONS

A modified protocol for the attainment of purified CECs and the first in vitro angiogenesis model of CECs were successfully established. We provided initial evidence that CECs had enhanced angiogenic potential and showed increased responsiveness to vascular endothelial growth factor.

The role of intraoperative monitoring of oculomotor and trochlear nuclei -safe entry zone to tegmental lesions

OBJECTIVE

A safe entry zone to tegmental lesions was identified based on intraoperative electrophysiological findings, the compound muscle action potentials (CMAP) from the extraocular muscles, and anatomic considerations. This entry zone is bordered caudally by the intramesencephalic path of the trochlear, laterally by the spinothalamic tract, and rostrally by the caudal margin of the brachium of the superior colliculus.

METHODS

Four intrinsic midbrain lesions were operated upon via the safe entry zone using the infratentorial paramedian supracerebellar approach. All lesions involved the tegmentum and included an anaplastic astrocytoma, a metastatic brain tumor, a radiation necrosis, and a cavernous angioma. CMAP were bilaterally monitored from the inferior recti (for oculomotor function) and superior oblique (for trochlear nerve function) muscles.

RESULTS

In three of four cases, CMAP related to the oculomotor nerve were obtained upon stimulation at the cavity wall after removal of the tumor. Stimulation at the surface of the quadrigeminal plate, however, did not cause any CMAP response. Using this monitoring as an indicator, the lesions were totally removed.

CONCLUSIONS

In the surgery of tegmental lesions, CMAP monitoring from extraocular muscles is particularly helpful to prevent damage to crucial neural structures during removal of intrinsic lesions, but less so to select the site of the medullary incision. The approach via the lateral part of the colliculi is considered to be a safe route to approach the tegmental lesions.

Cavernous hemangioma of the spinal cord - conservative or operative management?

Once believed to be extremely uncommon, due to magnetic resonance imaging cavernous hemangiomas of the spinal cord are detected with increasing frequency. Management of both symptomatic and asymptomatic intramedullary cavernous hamangiomas is therefore of growing importance. However, experience with treatment and follow-up is very limited. In particular, patients with multiple central nervous system cavernous hemangiomas represent a therapeutical dilemma. We present a patient with a ruptured intramedullary and multiple cerebral cavernous hemangiomas and a survey of current knowledge of epidemiology, pathophysiology and treatment options. We conclude that the benefit of operative treatment possibly decreases with the number of clinically silent vascular malformations.

Removal of an orbital apex hemangioma using an endoscopic transethmoidal approach: technical note

OBJECTIVE

The posterior orbit contains a number of important and vulnerable structures, including the optic nerve, the ophthalmic artery and vein, and the ocular muscles and their motor nerves, which makes surgical access to the lesion in this region quite difficult. Transfrontal, transfrontal-ethmoidal, and transmaxillary procedures have the disadvantage of possible injuries to a number of nontumor structures, whereas an endoscopic transethmoidal approach is a minimally invasive surgery for the retrobulbar lesions. Retrobulbar cavernous hemangioma was successfully removed by a transethmoidal approach.

METHODS

Tumor removal was performed in a patient with an intraconal cavernous hemangioma of approximately 15 mm in diameter. By a transethmoidal approach, the medial-inferior part of the orbit, as well as the apex of the orbit, were clearly visualized after endonasal ethmoidectomy. After the removal of the medial orbital bone, the orbital periosteum was incised and elevated. By elevating the orbital fat, the tumor could be identified separately from the orbital contents.

RESULTS

Cavernous hemangioma at the orbital apex was removed without complications.

CONCLUSION

An endoscopic transethmoidal approach, which requires no skin incision, is a minimally invasive surgery for retrobulbar orbital tumor, leading to excellent cosmetic results with less bleeding.

Resection of a left insular cavernoma aided by a simple navigational tool. Technical note

The management of cavernous malformations of the brain is markedly influenced by the location of the lesions themselves. In the last decade, resection of cavernomas arising in the dominant insular lobe has been deemed safe only with the guidance of neuronavigation. Most navigation equipment, however, shares some minor drawbacks, including costs, longer operating time, and a variable loss of accuracy due to intraoperative brain shift. In this paper the authors present the case of a left dominant insular cavernoma that was successfully removed using a novel form of navigation that they call magnetic resonance imaging-based corticotopography. This technique, which is unaffected by the brain shift phenomenon, provided a simple and inexpensive alternative to standard neuronavigation. Selected cases of subcortical brain lesions could be conveniently approached using the same technique.

Hemorrhage of cavernous malformations during pregnancy and in the peripartum period: causal or coincidence? Case report and review of the literature

There is growing evidence to suggest that pregnancy may increase the risk of hemorrhage from cavernous malformations (CMs). In the present case, a 21-year-old primigravida was admitted to the authors' neurosurgical service after a cesarean section. Three weeks before admission she had experienced rapidly progressive bilateral lower-extremity paresthesias. Spinal magnetic resonance (MR) imaging revealed the presence of an intramedullary thoracic lesion. On T2-weighted MR images, heterogeneous signal intensity with a rim of decreased intensity was demonstrated in the spine. The mass was successfully resected, and 1 year later the patient's symptoms had resolved completely. This is the fourth reported case of a spinal intramedullary CM that became symptomatic during pregnancy. The pathogenesis and management of this entity are reviewed.

Molecular genetics of familial cerebral cavernous malformations

Cerebral cavernous malformations (CMs) are angiographically occult neurovascular lesions that consist of enlarged vascular channels without intervening normal parenchyma. Cavernous malformations can occur as sporadic or autosomal- dominant inherited conditions. Approximately 50% of Hispanic patients with cerebral CMs have the familial form, compared with 10 to 20% of Caucasian patients. There is no difference in the pathological findings or presentation in the sporadic and familial forms. To date, familial CMs have been attributed to mutations at three different loci: CCM1 on 7q21.2, CCM2 on 7p15-p13, or CCM3 on 3q25.2-q27. The authors summarize the current understanding of the molecular events underlying familial CMs.

Are cavernous sinus hemangiomas and cavernous malformations different entities?

Cavernous hemangiomas that occur within the cavernous sinus (CS) are different from cerebral cavernous malformations (CMs) clinically, on imaging studies, and in their response to treatment. Moreover, CMs are true vascular malformations, whereas hemangiomas are benign vascular tumors. Because of these differences, the authors suggest that these two entities be analyzed and grouped separately. Unfortunately, despite these differences, much confusion exists in the literature as to the nature, behavior, and classification of these two distinct lesions. This confusion is exacerbated by subtle histological differences and the inconsistent use of nomenclature. The authors use the term "cavernous malformation" to refer to intraaxial lesions only; they prefer to use the term "cavernous sinus hemangioma" to refer to extraaxial, intradural hemangiomas of the CS.

Clinical progression and familial occurrence of cerebral cavernous angiomas: the role of angiogenic and growth factors

OBJECT

The authors studied the expression of angiogenic and growth factors and various proliferative indices in cavernous angiomas of the brain. The goal was to define whether the often progressive clinical course of both sporadic and familial forms of the lesion is correlated with different expression of these factors.

METHODS

Forty-three cavernomas of the brain were investigated with immunohistochemical studies and stained for four growth factors (vascular endothelial growth factor [VEGF], tenascin, transforming growth factor-b [TGFb], and platelet-derived growth factor [PDGF]), and for Ki-67 and bcl-2. The intensity of expression was tested in all cases in the walls of cavernoma vessels, in the perivascular tissue, and in the perilesional brain parenchyma. Among the 43 cavernomas, 32 were stable and sporadic single lesions less than 2 cm in size, whereas 11 were cavernomas larger than 2 cm (up to 6 cm). These larger cavernomas had more aggressive behavior (documented growth in five cases, mass effect in eight, significant hemorrhage in four), familial occurrence (six cases), and/or multiple lesions (five cases). The expression of VEGF, tenascin, and PDGF in cavernomas did not significantly differ in the two groups of patients, whereas TGFb expression was higher in the more aggressive forms of cavernomas. The expression of Ki-67 and bcl-2 was always absent in stable lesions, and it was positive in eight (72.7%) of 11 aggressive lesions. The perilesional brain parenchyma showed a significantly higher expression of TGFb, PDGF, and tenascin in more aggressive cavernomas.

CONCLUSIONS

The familial occurrence and more aggressive clinical behavior of cavernous angiomas of the brain are associated with higher expression of Ki-67 and bcl-2 in the cavernoma tissue, as in other proliferative lesions. These features are also associated with higher expression of some growth factors (excluding VEGF) in the perilesional brain parenchyma, suggesting that the neighboring vasculature and glia may be predisposed to and recruited for further growth and progression.

Bleeding of a familial cerebral cavernous malformation after prophylactic anticoagulation therapy. Case report

The risk of hemorrhage in cavernous malformations (CMs) depends on lesion, host, and environmental factors. Anticoagulation therapy is a well-known risk factor for intracerebral bleeding, but the occurrence of hemorrhages in patients with CMs has not been reported. Low molecular weight heparin therapy is generally considered to be safe, although significant hemorrhagic complications have recently been reported. The authors report a case of intralesional bleeding in a CM after prophylactic anticoagulation therapy was administered in a patient with the familial form of the disease. The leaky endothelial structure of CMs may constitute an unexpected target of the vascular effects of heparin.

Cavernoma of the foramen of Monro

✓The authors report on a patient who presented with an intraventricular mass located at the level of the foramen of Monro. The clinical presentation and neuroimaging appearance of the mass led to an initial diagnosis of colloid cyst. A neuroendoscopic approach offered a direct view of the ventricular lesion, which was found to be a cavernous angioma partially occluding the foramen of Monro. The lesion was then removed using microsurgery. In this report the authors highlight possible pitfalls in the diagnosis of some lesions of the third ventricle, and the possible advantages of using a combined endoscopic and microsurgical technique when approaching such lesions.

The association of venous developmental anomalies and cavernous malformations: pathophysiological, diagnostic, and surgical considerations

✓Developmental venous anomalies (DVAs) are often associated with intracranial cavernous malformations (CMs). The frequency of this association and the observation of de novo CMs located near a known, preexisting DVA raise speculations as to the possible etiopathogenetic relationship between the two. In this article, the authors review the recent literature dealing with the potential etiopathogenetic, prognostic, and therapeutic implications of the association between DVAs and CMs.

Cerebral cavernous malformations: clinical insights from genetic studies

✓ Familial disease is responsible for one third to one half of cerebral cavernous malformation (CCM) cases presenting to clinical attention. Much has been learned in the past decade about the genetics of these cases, which are all inherited in an autosomal dominant pattern, at three known chromosome loci. Unique features of inherited CCMs in Hispanic-Americans of Mexican descent have been described. The respective genes for each locus have been identified and preliminary observations on disease pathways and mechanisms are coming to light, including possible explanations for selectivity of neural milieu and relationships to endothelial layer abnormalities. Mechanisms of lesion genesis in cases of genetic predisposition are being investigated, with evidence to support a two-hit model emerging from somatic mutation screening of the lesions themselves and from lesion formation in transgenic murine models of the disease. Other information on potential inflammatory factors has emerged from differential gene expression studies. Unique phenotypic features of solitary versus familial cases have emerged: different associations with venous developmental anomaly and the exceptionally high penetrance rates that are found in inherited cases when high-sensitivity screening is performed with gradient echo magnetic resonance imaging. This information has changed the landscape of screening and counseling for patients and their families, and promises to lead to the development of new tools for predicting, explaining, and modifying disease behavior.

Clinical presentation and optimal management for intramedullary cavernous malformations

Object

Intramedullary cavernous malformations (CMs) account for approximately 5% of all intraspinal lesions. The purpose of this study was to define the spectrum of presentation for spinal intramedullary CMs and the results of microsurgery for these benign but clinically progressive lesions.

Methods

Retrospective chart review was performed in 26 patients with histologically diagnosed CMs. All patients had undergone preoperative magnetic resonance (MR) imaging studies. All patients were treated with a laminectomy and microsurgical resection of the malformation.

Conclusions

The MR imaging findings are diagnostic for intramedullary CMs; these lesions abut a pial surface and have a characteristic imaging pattern. Spinal intramedullary CMs present with either an acute onset of neurological compromise or a slowly progressive neurological decline. Acute neurological decline occurs secondary to hemorrhage inside the spinal cord. Chronic progressive myelopathy occurs due to microhemorrhages and resulting gliotic reaction to blood products. Surgery and total removal of the lesion tends to halt progression of symptoms.

Intraoperative rupture of brainstem cavernous malformation

✓Although cavernous malformations (CMs) are an important cause of intracranial hemorrhage, the natural history of these lesions is controversial. Both retrospective and prospective studies undertaken to define risk factors for hemorrhage from CMs have consistently identified the location of a lesion as a factor that has a significant impact on the rate of rupture, and brainstem CMs consistently have a higher rate of symptomatic hemorrhage than those at other locations. The mechanism underlying this disparity in rupture rates, however, remains obscure. Most authors attribute the difference, at least partially, to the sensitivity of the brainstem to hemorrhage. Regardless, the specific factors that cause a given CM to rupture are unknown.

The authors report their first encounter with an intraoperative rupture of a CM in the brainstem. This case underscores the risks encountered during the surgical approach to brainstem CMs and may provide insight into the pathophysiological mechanisms underlying the rupture of these lesions.

Neurosurgical management of cerebellar cavernous malformations

Object

The aim of this study was to analyze cerebellar cavernous malformations (CMs) with respect to epide-miological, clinical, radiological, and therapeutic aspects.

Methods

Between 1984 and 2004, 100 patients were surgically treated for intracranial CMs at the Division of Neurosurgery of Federal University of São Paulo. The authors reviewed the records of 10 patients whose lesions were located in the cerebellum.

There were four male and six female patients (ratio 1:1.5) whose ages ranged from 14 to 45 years (mean age 33 years). Clinical presentation was sudden or acute in all cases, and neuroimaging examinations performed in all patients demonstrated signs of bleeding. The mean size of the malformations was 4.6 cm, and in all but one patient the lesions were totally removed without complications. After a mean follow-up period of 70 months, all patients were considered to be in good or excellent clinical condition.

Conclusions

Cerebellar CMs should be analyzed separately from other posterior fossa CMs. These lesions can reach large sizes and cause massive hemorrhages, resulting in acute or sudden presentation. Surgery is a safe and effective option that provides a curative treatment when a complete removal is achieved.

Drug-resistant temporal lobe epilepsy due to cavernous malformations

Object

Supratentorial cavernous angiomas may be associated with drug-resistant focal epilepsy. Surgical removal of the malformation may result in seizure control in a number of patients, although in most studies a long history and high frequency of attacks have been recognized as indicators of unfavorable seizure outcome. In the literature, there are no clear indications regarding the optimal diagnostic presurgical workup and the surgical strategy for this particular subgroup of patients with symptomatic epilepsy. In this paper the authors focus on the preoperative workup and the surgical management of the disease in eight consecutive patients undergoing surgery for drug-resistant temporal lobe epilepsy (TLE) due to cavernous malformations (CMs), and the relevant literature on this issue is also reviewed.

Methods

Preoperatively, all patients were assessed using a noninvasive protocol aimed at localizing the epileptogenic zone on the basis of anatomical, electrical, and clinical criteria. The presurgical assessment yielded an indication for lesionectomy in two cases, lesionectomy plus anteromesial temporal lobectomy in four cases, and lesionectomy plus extended temporal lobectomy in two cases. At follow-up examinations, seizure, neuropsychological, and psychiatric outcomes were all evaluated. Seven patients were categorized in Engel Class IA (seizure free), and one was categorized in Engel Class IB (occasional auras only). No adverse effects on neuropsychological or psychosocial functioning were observed.

Conclusions

Epilepsy surgery can be performed with excellent results in patients with intractable TLE caused by CMs. Noninvasive presurgical evaluation of these patients may enable a tailored approach, providing complete seizure relief in most cases.

Cerebral cavernous malformations and epilepsy

✓Seizures and epilepsy are frequent clinical manifestations of cerebral cavernous malformations (CCMs) and represent the most common symptomatic presentation of supratentorial lesions. Clinicians often diagnose CCMs in patients after a first seizure, or in some cases after obtaining neuroimaging studies in patients suffering from chronic epilepsy previously thought to be idiopathic. In some cases, the lesion is clinically significant solely because of its epileptogenicity, but in others there may be concern about potential hemorrhage or focal neurological deficits from a similar lesion.

The authors present current pathophysiological concepts related to epilepsy associated with CCMs. They discuss the spectrum of seizure disorders associated with these lesions and review the natural history, prognosis, and options for therapeutic intervention.

Review of the literature on de novo formation of cavernous malformations of the central nervous system after radiation therapy

✓In this paper the authors review the literature concerning de novo cavernoma formation after radiation treatment. PubMed and MEDLINE database searches were performed. Data were compiled on all patients in whom de novo cavernomas formed after radiation treatment and whose cases were reported in the literature. The authors found reports in the literature of 76 patients in whom cavernomas formed de novo after radiation treatment. The mean age of the patients was 11.7 years, and the majority of these lesions occurred in males. The patients received a mean radiation dose of 60.45 Gy. The mean latency period before detection of the cavernoma was 8.9 years, and most of these lesions were detected incidentally. In symptomatic patients, the most common presenting symptoms were seizures. Thirty-seven of the patients had evidence of hemorrhage, and 54% of these required surgical intervention.

De novo formation of cavernomas after radiation treatment is a relatively rare phenomenon. Patients in whom these cavernomas develop need to be followed closely because there is a propensity for the lesions to hemorrhage. Surgical intervention to treat symptomatic lesions has a favorable outcome.

The Anterolateral Partial Vertebrectomy Approach for Ventrally Located Cervical Intramedullary Cavernous Angiomas

OBJECTIVE:

We report three cases with ventral cervical intramedullary cavernous angiomas. An anterolateral partial vertebrectomy was performed to surgically approach and successfully resect these lesions.

MATERIALS AND METHODS:

All three patients presented with numbness in the upper extremities and investigation revealed a cavernous angioma on the ventral aspect of the spinal cord in each case. The lesion was exposed by an anterolateral partial vertebrectomy in all cases. Postoperative stabilization was achieved by using autografted iliac bone in all patients. In two patients, locking screws and plates were also used.

RESULTS:

Complete resection of the cavernous angioma was performed in all patients. There was symptomatic relief in all cases, and there was no postoperative morbidity.

CONCLUSION:

Anterolateral partial vertebrectomy provides direct exposure and is probably an ideal approach for selected cases with ventrally located intramedullary cavernous angiomas.

Cavernous malformation within a schwannoma: review of the literature and hypothesis of a common genetic etiology

The finding of cavernous malformations within tumors of the central or peripheral nervous system is a rare occurrence. We report a case of a histologically proven cavernous malformation found within an eighth cranial nerve schwannoma in a 76-year-old man. The patient presented with progressive loss of hearing on the left, facial pain and dysesthesia. Symptoms improved significantly after the tumor was subtotally resected through a left retrosigmoid craniotomy. Including the present report, 34 cases of cavernous malformations associated with tumors of nervous system origin, 24 cases (71%) involving tumors of Schwann cell origin, and 9 cases (26%) involving gliomas have been published. The cases were classified into two forms based on the type of association. Conjoined association, in which the cavernous malformation is located within the tissue of the nervous system tumor, and discrete association, in which the cavernous malformation and nervous system tumor are in separate locations. We explore the etiology of this association and hypothesize that a common genetic pathway may be involved in a majority of these cases.

Cavernous malformation of the internal auditory canal

Cavernous malformations of the internal auditory canal are a rare clinical entity that, however, should be considered in the differential diagnosis of intracanalicular masses. Even though this type of malformation is usually associated with an evident gadolinium enhancement at MR examination, in some patients, like in this case, the signal characteristics may be not sufficiently specific to allow the correct preoperative diagnosis. Nevertheless, the clinical history, in particular, a rapid onset of cranial nerve deficits, lead to the suspicion of a vascular malformation.

Trigonal cavernous angiomas: report of three cases and review of literature

BACKGROUND

Intraventricular cavernous angiomas are very rare. Only few cases of trigonal angiomas have been reported.

CASE DESCRIPTION

We report three cases of trigonal cavernous angiomas who presented with raised intracranial pressure or seizures and who underwent total excision with a good recovery. We also review the literature and discuss surgical approaches.

CONCLUSION

On magnetic resonance imaging, intraventricular cavernous angiomas lack the hemosiderin ring characteristically seen around parenchymal cavernous angiomas. This explains why trigonal cavernous angiomas can mimic malignant neoplasm on imaging, and they should be considered in the differential diagnosis of intraventricular masses. Total excision should be the goal of surgery.

Early surgery for brainstem cavernomas

BACKGROUND

The purpose was to review our experience with the surgical management of brainstem cavernomas (BSCs) and especially the impact of the surgical timing on the clinical outcome.

METHOD

We retrospectively reviewed 22 patients harboring a BSC, who underwent 23 procedures.

FINDINGS

Surgery was carried out during the early stage after the last haemorrhage, with a mean delay of 21.6 days (range 4-90 days). Sixteen procedures were performed after a first bleeding event while seven after multiple bleedings. Complete resection was achieved in 19 patients (86.4%). Early after surgery, 12 patients (52.2%) improved neurologically, 5 (21.7%) were stable and 6 (26.1%) worsened. New postoperative deficits were noted after 9 procedures (39.1%). Statistically significant factors for postoperative aggravation were: late surgery (P = 0.046) and multiple bleedings (P = 0.043). No patient operated on within the first 19 days after bleeding did worsen (n = 11), as opposed to 6 out of 12 who did when operated on later. After a mean follow-up of 44.9 months, 20 patients (90.9%) were improved, 1 patient (4.6%) was worse and 1 patient was lost to follow-up (4.6%), after reoperation for rebleeding of a previously completely resected cavernoma. Late morbidity was reduced to 8.6%. The mean Glasgow Outcome Scale (GOS) at the end of the follow-up period was 4.24, compared to a mean preoperative GOS of 3.22 (P<0.001). Complete neurological recovery of motor deficits, sensory disturbances, cranial nerves (CNs), internuclear ophtalmoplegia and cerebellar dysfunction were respectively 41.7%, 38.5%, 52.6%, 60.0% and 58.3%. Among the most affected CNs: CN 3, CN 5 and CN 7 were more prone to completely recover, respectively in 60.0%, 70.0% and 69.2%.

CONCLUSIONS

Surgical removal of BSCs is feasible in experienced hands with acceptable morbidity and good outcome. Early surgery and single bleeding were associated with better surgical results.

Neuroendoscopic Appearance of an Intraventricular Cavernous Angioma Blocking the Foramen of Monro-Case Report-

A 47-year-old woman presented with unilateral ventricular enlargement detected by magnetic resonance imaging during a medical checkup. Neuroendoscopic exploration identified a multilocular lesion in which dark red fluid formed a niveau near the right side of the foramen of Monro. The diagnosis was intraventricular cavernous angioma. Restricted flow of cerebrospinal fluid at the foramen of Monro was observed. Xanthochromia, which seemed to be due to previous bleeding, was observed at the fornix. When the neuroendoscope touched the angioma, the wall collapsed and bled. Endoscopic removal of the angioma was abandoned, and craniotomy and resection of the angioma were performed. No new neurological anomalies were observed after surgery. Preoperative diagnosis of intraventricular cavernous angioma is difficult based on neuroimaging. Neuroendoscopy is effective for diagnosis and the decision-making process regarding treatment.

Analysis of Pain Resolution after Surgical Resection of Intramedullary Spinal Cord Cavernous Malformations

OBJECTIVE:

To determine the short- and long-term effects of surgical resection of intramedullary spinal cavernous malformations on preoperative pain.

METHODS:

Between 1988 and 2003, 53 intramedullary spinal cavernous malformations were surgically managed. A retrospective analysis of this cohort revealed 23 (43%) patients who presented with pain as a clinically relevant feature. Long-term evaluation of pain outcomes was available in 21 patients. Pain outcomes were characterized as improved, unchanged, or worse compared with preoperative and immediate postoperative status.

RESULTS:

Seven patients presented with radiculopathy, 12 with central pain, and four with both. Immediately after surgery, pain symptoms improved in 18 (78%) patients, were unchanged in 5 (22%), and were worse in none compared with the patients' preoperative status (n = 23). During the follow-up period, 11 (52%) patients improved, nine (43%) remained at their preoperative baseline, and one (5%) was worse compared with their preoperative levels of pain. The difference in postoperative and long-term pain status was statistically significant (P = 0.031).

CONCLUSION:

The surgical efficacy for improving pain related to intramedullary spinal cavernous malformations may be worse than implied in the literature. Although pain relief immediately after surgery is good, we found that recurrence is common and that only approximately 50% of patients report long-term benefit. Despite the significant limitations of this retrospective study, these data may serve as a guide when counseling patients preoperatively to help them to maintain realistic expectations about outcomes.

CCM3 mutations are uncommon in cerebral cavernous malformations

Cerebral cavernous malformations (CCMs) are characterized by abnormally enlarged capillary cavities without intervening brain parenchyma. Mutations in the gene PDCD10 have been found in CCM families linked to the CCM3 locus. The authors screened this gene in 15 families that did not have a CCM1 or CCM2 mutation. Only two novel mutations were found, suggesting that mutations in this gene may only account for a small percentage of CCM familial cases.

Unusual locations for cavernous hemangiomas: report of two cases and review of the literature

Cavernous hemangiomas are most commonly found within the subcortical neural parenchyma near the fissura Rolandi, in the basal ganglia, or in the brain stem. Because of advancing neuro-imaging technology and thus resulting in a higher incidence of cavernous hemangiomas they have rising impact in neurosurgery. We present two unusual cases of extra-axial cavernous hemangiomas: one located at the frontal falx, the other within the bone of the right frontal bone. We discuss these and other cases in the literature with respect to the more common differential diagnoses and the appropriate therapy regimen for cavernous hemangiomas in these locations.

Cavernous malformation after radiation therapy for astrocytoma in adult patients: report of 2 cases

Radiation-induced cavernous malformations are rarely reported, and most cases have been children. We describe two adult patients with cavernous malformation after irradiation for astrocytoma. Magnetic resonance (MR) imaging, at their ages of 53 years, showed a cavernous malformation in the irradiated field 26 and 10 years after resection and irradiation, respectively. Cavernous malformations were confirmed by the histopathological examination in the both cases. Radiation-induced cavernous malformations are rare in adult patients with astrocytoma. One reason why we found two such cases was that these patients had been successfully treated for astrocytoma and had long follow-up periods.