The natural history of familial cavernous malformations: results of an ongoing study

Routinely Performed Serial Follow-Up Imaging in Asymptomatic Patients With Multiple Cerebral Cavernous Malformations Has No Influence on Surgical Decision Making

Background: The best strategy to perform follow-up of patients with multiple cerebral cavernous malformations (mCCM) is unclear due to the unpredictable clinical course. Still, serial radiological follow-up is often performed. The objective of this work was to critically question whether active follow-up by serial imaging is justified and has an impact on clinical decision making.

Methods: We included all consecutive patients with mCCM treated and followed at our Department between 2006 and 2016. Patient data were collected and analyzed retrospectively.

Results: From a total number of 406 patients with CCM, n = 73 [18.0%; mean age at first diagnosis 45.2 years (±2.4 SE); n = 42 male (57.5 %)] were found to harbor multiple lesions (≤5 CCM in 58.9%; 6–25 in 21.9%; ≥ 25 in 19.2%). All of them were followed for a mean of 6.8 years (±0.85 SE). Conservative treatment was suggested in 43 patients over the complete follow-up period. Thirty patients underwent surgical extirpation of at least one CCM lesion. Forty-three surgical procedures were performed in total. During 500.5 follow-up years in total, routinely performed follow-up MRI in asymptomatic patients lead to an indication for surgery in only two occasions and even those two were questionable surgical indications.

Conclusion: Routinely performed follow-up MRI in asymptomatic patients with mCCM is highly questionable as there is no evidence for therapeutic relevance.

Cerebral Microbleeds: Imaging and Clinical Significance

Cerebral microbleeds (CMBs), also referred to as microhemorrhages, appear on magnetic resonance (MR) images as hypointense foci notably at T2*-weighted or susceptibility-weighted (SW) imaging. CMBs are detected with increasing frequency because of the more widespread use of high magnetic field strength and of newer dedicated MR imaging techniques such as three-dimensional gradient-echo T2*-weighted and SW imaging. The imaging appearance of CMBs is mainly because of changes in local magnetic susceptibility and reflects the pathologic iron accumulation, most often in perivascular macrophages, because of vasculopathy. CMBs are depicted with a true-positive rate of 48%-89% at 1.5 T or 3.0 T and T2*-weighted or SW imaging across a wide range of diseases. False-positive "mimics" of CMBs occur at a rate of 11%-24% and include microdissections, microaneurysms, and microcalcifications; the latter can be differentiated by using phase images. Compared with postmortem histopathologic analysis, at least half of CMBs are missed with premortem clinical MR imaging. In general, CMB detection rate increases with field strength, with the use of three-dimensional sequences, and with postprocessing methods that use local perturbations of the MR phase to enhance T2* contrast. Because of the more widespread availability of high-field-strength MR imaging systems and growing use of SW imaging, CMBs are increasingly recognized in normal aging, and are even more common in various disorders such as Alzheimer dementia, cerebral amyloid angiopathy, stroke, and trauma. Rare causes include endocarditis, cerebral autosomal dominant arteriopathy with subcortical infarcts, leukoencephalopathy, and radiation therapy. The presence of CMBs in patients with stroke is increasingly recognized as a marker of worse outcome. Finally, guidelines for adjustment of anticoagulant therapy in patients with CMBs are under development. ^© RSNA, 2018.

Cavernous brain malformations and their relation to black blood MRI in respect to vessel wall contrast enhancement

Background

Inflammatory responses are implicated as crucial patho-mechanisms of vascular brain malformations. Inflammation is suggested to be a key contributor to aneurysm rupture; however it is unclear whether inflammation contributes similarly to bleeding of cerebral cavernous malformations (CCMs). Black blood MRI is a sequence which identifies inflammation in blood vessel walls and in the present study is used to detect inflammatory response in CCMs.

Methods

Fifteen patients with 17 CCMs treated in our department in 2017 were retrospectively analysed. All patients received black blood MRIs and the results were analysed in correlation with, size and bleeding of CCMs.

Results

Size and bleeding status of CCMs did not correlate with contrast enhancement in the CCM wall. One of 3 patients with bleeding displayed contrast enhancement in black blood MRI, whereas the others had non enhancing lesions. Because of the small number of cases a statistical analysis was not performed.

Conclusion

In this limited cohort, inflammatory reactions in CCMs could not be detected by black blood MRI suggesting that the level of inflammation is minimal in these lesions and those different patho-mechanisms play a more important role in the rupture of CCMs.

Cerebral amyloid angiopathy: Review of clinico-radiological features and mimics

Cerebral amyloid angiopathy (CAA) is an important cause of lobar intracerebral haemorrhage (ICH) in the elderly, but has other clinico-radiological manifestations. In the last two decades, certain magnetic resonance imaging (MRI) sequences, namely gradient-recalled echo imaging and the newer and more sensitive susceptibility-weighted imaging, have been utilised to detect susceptibility-sensitive lesions such as cerebral microbleeds and cortical superficial siderosis. These can be utilised sensitively and specifically by the Modified Boston Criteria to make a diagnosis of CAA without the need for 'gold-standard' histopathology from biopsy. However, recently, other promising MRI biomarkers of CAA have been described which may further increase precision of radiological diagnosis, namely chronic white matter ischaemia, cerebral microinfarcts and lobar lacunes, cortical atrophy, and increased dilated perivascular spaces in the centrum semiovale. However, the radiological manifestations of CAA, as well as their clinical correlates, may have other aetiologies and mimics. It is important for the radiologist to be aware of these clinico-radiological features and mimics to accurately diagnose CAA. This is increasingly important in a patient demographic that has a high prevalence for use of antiplatelet and antithrombotic medications for other comorbidities which inherently carries an increased risk of ICH in patients with CAA.

Susceptibility-weighted magnetic resonance imaging of cerebrovascular sequelae after radiotherapy for pediatric brain tumors

BACKGROUND AND PURPOSE

Due to sensitive neuroimaging techniques, cerebrovascular complications such as cerebral microbleeds (CMB) and cerebral cavernous malformations (CCM) are increasingly recognized as considerable late effects after treatment for pediatric brain tumor. The aim of this study was to analyze CMB in a cohort of patients after cranial irradiation therapy for medulloblastoma or other pediatric brain tumors using susceptibility-weighted magnetic resonance imaging (SWI).

MATERIALS AND METHODS

Forty former pediatric brain tumor patients were enrolled in this prospective cross-sectional study and examined by cranial MRI including SWI sequences. Cerebral microbleeds, clinical symptoms and disability were evaluated.

RESULTS

Thirty-six (90%) of the examined individuals (mean follow-up age 22.2 y; mean follow-up time 13.5 y) were affected by CMB. Longer follow-up time and higher craniospinal irradiation doses correlated with higher total lesion count (p < 0.01). Thirteen patients (32.5%) presented with clinical symptoms. Individuals with CMB were more severely disabled than patients without CMB (p < 0.05).

CONCLUSIONS

Cerebrovascular sequelae occur frequently after treatment for pediatric brain tumor. In this study, a remarkable part of pediatric brain tumor patients presents with CMB. As a sign of vascular damage, they can cause clinical symptoms and may correspond to neurocognitive decline. Further studies are needed to standardize MRI protocols and to improve quality of long-term follow-up.

A benchmark approach to hemorrhage risk management of cavernous malformations

Objective

Despite the low annual risk of hemorrhage associated with a cavernous malformation (CM) (0.6%–1.1% per year), the risk of rehemorrhage rate and severity of neurologic deficits is significantly higher; therefore, we aimed to evaluate the rupture risk of CMs depending on various factors.

Methods

We retrospectively analyzed medical records of all patients with CM admitted to our institution between 1999 and April 2016. Cavernoma volume, location of the lesion, existence of a developmental venous anomaly (DVA), number of cavernomas, and patient characteristics (sex, age, hypertension, and antithrombotic therapy) were assessed.

Results

One hundred fifty-four patients with CM were included; 89 (58%) ruptured CMs were identified. In statistical univariable analysis, the existence of a DVA was significantly higher in the ruptured cavernoma group (p < 0.001; odds ratio [OR] 4.6). A multivariable analysis of all included independent risk factors designated young age (<45 years) (p < 0.05; OR 2.2), infratentorial location (p < 0.01; OR 2.9), and existence of a DVA (p < 0.0001; OR 4.7) with significantly higher risk of rupture in our patient cohort. A separate analysis of these anatomical locations, supratentorial vs infratentorial, indicated that the existence of a DVA (p < 0.01; OR 4.16) in ruptured supratentorial cases and CM volume (≥1 cm3) (p < 0.0001; OR 3.5) in ruptured infratentorial cases were significant independent predictors for hemorrhage.

Conclusions

Young age (<45 years), infratentorial location, and the presence of a DVA are associated with a higher hemorrhage risk. CM volume (≥1 cm3) and the existence of a DVA were independently in accordance with the anatomical location high risk factors for CM rupture.

Cerebral Cavernous Malformations: An Update on Prevalence, Molecular Genetic Analyses, and Genetic Counselling

Based on the latest gnomAD dataset, the prevalence of symptomatic hereditary cerebral cavernous malformations (CCMs) prone to cause epileptic seizures and stroke-like symptoms was re-evaluated in this review and calculated to be 1:5,400-1:6,200. Furthermore, state-of-the-art molecular genetic analyses of the known CCM loci are described which reach an almost 100% mutation detection rate for familial CCMs if whole genome sequencing is performed for seemingly mutation-negative families. An update on the spectrum of CCM1, CCM2, and CCM3 mutations demonstrates that deep-intronic mutations and submicroscopic copy-number neutral genomic rearrangements are rare. Finally, this review points to current guidelines on genetic counselling, neuroimaging, medical as well as neurosurgical treatment and highlights the formation of active patient organizations in various countries.

Neuro-Ophthalmic Manifestations of Intracranial Cavernous Hemangiomas

PURPOSE:

To describe the neuro-ophthalmic manifestations of patients with intracranial cavernous hemangiomas (cavernomas).

Methods

A retrospective review of all patients with intracranial cavernomas with neuro-ophthalmic manifestations who were treated at the Royal Adelaide Hospital in Australia between 1994 and 2004.

Results

There were nine patients (three men and six women), with a mean age of 39 years (range 22–61). There was one cerebellar lesion, two thalamic, four pontine, one midbrain/pontine, and one midbrain. Ophthalmic presentations included internuclear ophthalmoplegia (one patient), third cranial nerve (CN) palsy (one patient), fourth CN palsy (one patient), and sixth CN palsy (six patients). Three patients underwent extraocular muscle surgery, and six were treated medically or observed. In five patients the diplopia resolved, in three it was only mild, and in one patient no significant change was noted during the follow-up period.

Conclusions

Diplopia is the main neuro-ophthalmic manifestation of intracranial cavernomas. Sixth CN palsy is the most common cause. Neurosurgical or conservative treatment leads to improvement in most cases, and later use of spectacles or extraocular muscle surgery may lead to further improvement.

Risk Factors for Unfavorable Outcomes in Surgically Treated Brainstem Cavernous Malformations

OBJECTIVE

Brainstem cavernous malformations (BSCMs) account for up to 18% of all intracranial cavernous malformations. Due to their complex anatomic location, they represent a significant challenge for neurosurgeons. As such, the identification of risk factors associated with negative outcomes is of significant importance. We analyze a series of 50 cases of BSCMs treated surgically in order to identify risk factors for unfavorable outcomes.

METHODS

Patients who underwent surgical resection of BSCM at our institution between 2000 and 2015 were retrospectively reviewed. Univariate and multivariable logistic regression models were used to identify predictors of unfavorable outcomes, defined as those with a modified Rankin score (mRs) of >2.

RESULTS

Fifty Latin American patients, with a mean age of 35.85 ± 13.06 years, consisting of 29 females (58%) and 21 males (42%), underwent surgical resection. Mean modified Rankin Scale (mRs) score at admission was 2.6 ± 1.05, and the mean BCSM size was 18.00 ± 7.19 mm. The rate of gross total resection was 92%. Overall, 80% of patients showed improved or unchanged clinical status at the last follow-up period; however, only 58% of patients had a favorable outcome with a mean mRs of 2.33 ± 1.136. Multivariable logistic binary regression identified hemorrhagic recurrence (P = 0.040), lower cranial nerve deficit (P = 0.019), and BSCMs >15 mm in diameter (P = 0.006) as predictive factors for unfavorable surgical outcomes.

CONCLUSION

BSCM size, compromise of lower cranial nerves, and hemorrhagic recurrence before surgery were identified as risk factors associated with unfavorable outcomes of surgically treated BSCMs in this cohort.

Electromagnetic navigation-guided neuroendoscopic removal of radiation-induced intraforniceal cavernoma as a late complication of medulloblastoma treatment

INTRODUCTION

Medulloblastoma is the most frequent malignant brain tumour in children. Radiation-induced cavernous haemangiomas (RICHs) are a known late complication of radiation exposure, especially in young children.

CASE REPORT

We present a patient who underwent subtotal resection of posterior fossa medulloblastoma with subsequent chemotherapy and radiotherapy at the age of 10 years. A new lesion in the region of the left foramen of Monro appeared 16 years later. Based on the imaging results, metastasis or radiation-induced cavernoma was considered. The lesion had the same appearance on imaging as a rarely published intraventricular cavernoma of the foramen of Monro. Unlike the cavernoma of the foramen of Monro, this lesion was subependymal and intraforniceal. Using electromagnetic navigation and neuroendoscopy, the lesion was completely removed. Histopathological examination revealed a cavernous haemangioma.

CONCLUSION

This is a unique case of intraforniceal paraforaminal cavernoma that was successfully removed endoscopically using electromagnetic neuronavigation and without neurological sequelae.

Intraoperative high-field magnetic resonance imaging, multimodal neuronavigation, and intraoperative electrophysiological monitoring-guided surgery for treating supratentorial cavernomas

Objective

To determine the beneficial effects of intraoperative high-field magnetic resonance imaging (MRI), multimodal neuronavigation, and intraoperative electrophysiological monitoring-guided surgery for treating supratentorial cavernomas.

Methods

Twelve patients with 13 supratentorial cavernomas were prospectively enrolled and operated while using a 1.5 T intraoperative MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring. All cavernomas were deeply located in subcortical areas or involved critical areas. Intraoperative high-field MRIs were obtained for the intraoperative “visualization” of surrounding eloquent structures, “brain shift” corrections, and navigational plan updates.

Results

All cavernomas were successfully resected with guidance from intraoperative MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring. In 5 cases with supratentorial cavernomas, intraoperative “brain shift” severely deterred locating of the lesions; however, intraoperative MRI facilitated precise locating of these lesions. During long-term (>3 months) follow-up, some or all presenting signs and symptoms improved or resolved in 4 cases, but were unchanged in 7 patients.

Conclusions

Intraoperative high-field MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring are helpful in surgeries for the treatment of small deeply seated subcortical cavernomas.

Endothelial cell disease: emerging knowledge from cerebral cavernous malformations

PURPOSE OF REVIEW

Endothelial cells dysfunctions are crucial determinants of several human diseases. We review here the most recent reports on endothelial cell defects in cerebral cavernous malformations (CCMs), particularly focusing on adherens junctions. CCM is a vascular disease that affects specifically the venous microvessels of the central nervous system and which is caused by loss-of-function mutation in any one of the three CCM genes (CCM1, 2 or 3) in endothelial cells. The phenotypic result of these mutations are focal vascular malformations that are permeable and fragile causing neurological symptoms and occasionally haemorrhagic stroke.

RECENT FINDINGS

CCM is still an incurable disease, as no pharmacological treatment is available, besides surgery. The definition of the molecular alterations ensuing loss of function mutation of CCM genes is contributing to orientate the testing of targeted pharmacological tools.Several signalling pathways are altered in the three genotypes in a similar way and concur in the acquisition of mesenchymal markers in endothelial cells. However, also genotype-specific defects are reported, in particular for the CCM1 and CCM3 mutation.

SUMMARY

Besides the specific CCM disease, the characterization of endothelial alterations in CCM has the potentiality to shed light on basic molecular regulations as the acquisition and maintenance of organ and vascular site specificity of endothelial cells.

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.

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

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

Prevalence of cerebral cavernous malformations associated with developmental venous anomalies increases with age

BACKGROUND AND PURPOSE

To test the hypothesis that the prevalence of cerebral cavernous malformation (CCM) associated with developmental venous anomalies (DVAs) increases with age, we studied the age-related prevalence of DVA-associated CCM among patients with DVAs.

MATERIALS AND METHODS

Patients with DVAs on contrast-enhanced MRI exams performed over a 2-year period were included in this study. A single neuroradiologist reviewed all imaging exams for the presence of CCMs. Baseline demographic data collected included age, gender, presence of CNS neoplasm, history of cranial radiation, and history of seizure. Patients were divided into age groups based on decade of life. Cochran-Armitage trend tests were performed to determine if increasing age was associated with CCM prevalence.

RESULTS

A total of 1689 patients with DVAs identified on contrast-enhanced MRI were included. Of these patients, 116 (6.9%) had a cavernous malformation associated with the DVA. There was a significant positive association between age and the prevalence of DVA-associated CCM (P = 0.002). The prevalence of DVA-associated CCM was 0.8% for the 0-10 age group, 1.6% for the 11-20 age group, 7.5% for the 21-30 age group, 9.5% for the 31-40 age group, 6.1% for the 41-50 age group, 6.3% for the 51-60 age group, 7.4% for the 61-70 age group, and 11.6% for the >70 age group (P < .0001).

CONCLUSIONS

Our study demonstrated an age-related increase in prevalence of DVA-associated cavernous malformations among patients with DVAs. These findings suggest that DVA-associated cavernous malformations are acquired lesions.

[Cavernomas of the central nervous system : Observational study of 111 patients]

PURPOSE

The prevalence of cavernomas (cavernous hemangioma) is 0.1-0.7%. Cavernomas are often found as an incidental finding within the framework of magnetic resonance imaging (MRI) examinations in mainly young and healthy patients. In the literature, the reported risk of hemorrhage varies greatly and is sometimes higher than that of aneurysms, which is surprising given that cavernomas are part of the low blood pressure system. After the diagnosis the medical practitioner and the patient have to decide on the further therapy, either surgical removal or the strategy of watchful waiting (conservative treatment). The aim of our study was to determine the frequency of bleeding of cavernomas and the consequences and to determine the satisfaction of patients with treatment. All these aspects should make the therapeutic decision easier for medical practitioners.

MATERIAL AND METHODS

The study included all patients who were treated in the military hospital in Ulm during the period 2002-2012 and with the diagnosis of one or more cavernomas of the central nervous system (CNS) detected by MRI. This resulted in a total number of 111 patients. We recorded the epidemiological data and analyzed all cavernomas with respect to the location, size, treatment, side effects, etc. Furthermore, all included patients were sent a comprehensive questionnaire about symptoms, course of the disease and the quality of life. The response rate was 38%. All the collected data were analyzed with respect to the various aspects.

RESULTS

Depending on the definition of a bleeding event of a cavernoma and selection of the observational period, the probability of a hemorrhage risk ranged from 1.3% to 5.9% per patient year. This relatively high proportion is, however, put into perspective by the mostly mild consequences of a bleeding event. Many cavernomas, which were detected as an incidental finding showed signs of previous bleeding but the patients remained free of symptoms. Additionally, there was no patient in this collective who suffered serious consequences due to a bleeding event. Of the patients with temporal cavernomas 45% had symptomatic epilepsy. The results of the patient survey were heterogeneous. Some patients stated that in retrospect they would not choose surgical treatment again.

CONCLUSION

As a result of our findings we think it is important to critically look at the indications for surgical removal of cavernomas and special attention must be paid to informed consent of the patient. The frequent appearance of temporal cavernomas and their propensity to epileptic seizures is an essential aspect, which certainly influences the therapeutic decision. Although cavernomas are a venous malformation in the low blood pressure system, the determined frequency of hemorrhage was 5.9%, which was higher than expected but which is confirmed by other studies. Reports on severe sequelae of cavernoma bleeding are also rare in the literature, which relativizes the resulting danger of the relatively high probability of hemorrhage.

Novel loss of function mutation in KRIT1/CCM1 is associated with distinctly progressive cerebral and spinal cavernous malformations after radiochemotherapy for intracranial malignant germ cell tumor

PURPOSE

Cerebrospinal cavernous malformations (CCMs) are vascular lesions characterized by dilated and leaky capillary caverns. CCMs can cause seizures, focal neurological deficits or acute intracranial hemorrhage; however, most patients are asymptomatic. CCMs occur either sporadically or as a familial autosomal-dominant disorder. We present a clinical and molecular study of a patient with distinctive cerebral and spinal cavernous malformations following radiochemotherapy for a malignant brain tumor.

METHODS

The patient had multiple magnet resonance imaging (MRI) examinations of his brain and spine following radiochemotherapy for a primary intracranial germ cell tumor (GCT), as part of his oncologic follow-up. The MRI sequences included susceptibility-weighted imaging (SWI). The coding exons and their flanking intronic regions of KRIT1/CCM1 gene were analyzed for mutations by polymerase chain reaction (PCR) and direct sequencing.

RESULTS

MRI revealed numerous cerebral and spinal microhemorrhages and pronounced cavernous malformations that progressed with subsequent follow-up imaging. Genetic analysis demonstrated a novel heterozygous KRIT1/CCM1 two base pair deletion (c.1535_1536delTG) in exon 14. This deletion leads to a frameshift with a premature stop codon at nucleotide position 1553 and a highly likely loss of function of the KRIT1 protein.

CONCLUSION

We describe a patient with a novel heterozygous germ line loss of function mutation in KRIT1, which is associated with rapid-onset and highly progressive CCMs after radiochemotherapy for a malignant brain tumor.

Population-Based Prevalence of Cerebral Cavernous Malformations in Older Adults: Mayo Clinic Study of Aging

Importance

The prevalence of cerebral cavernous malformation (CCM) is unknown. Case ascertainment in most previous studies was based on autopsy data or clinical convenience samples, often without detailed clinical or radiologic information.

Objective

To determine the prevalence of CCM in a population-based sample of older adults.

Design, Setting, and Participants

This prospective imaging study included 4721 participants aged 50 to 89 years who were enrolled between January 1, 2004, and December 15, 2015, in the Mayo Clinic Study of Aging, a longitudinal, population-based study of residents of Olmsted County, Minnesota. An age- and sex-stratified sampling strategy was used to randomly select participants from Olmsted County using the medical records linkage system of the Rochester Epidemiology Project. Participants were invited to undergo brain magnetic resonance imaging (MRI). Of the 4721 participants, 2715 had an evaluable MRI. All images were reviewed by a board-certified neuroradiologist, and MRI reports were searched for the terms cavernous malformation, cavernous angioma, and cavernoma. Two vascular neurologists reviewed MRIs, and potential CCMs were classified using Zabramski classification. Medical records of the identified individuals with CCM were reviewed along with their demographic information, medical history, and any symptoms referable to the identified CCM lesion.

Main Outcomes and Measures

Prevalence of CCM and clinical and radiologic characteristics of study participants with CCM.

Results

Of the 2715 participants who underwent MRI scans, 12 (0.44%) had CCM. With the use of inverse probability weights to adjust for participation bias, the overall prevalence was 0.46% (95% CI, 0.05-0.86). The age-adjusted prevalence was found to be 0.61% (95% CI, 0-1.47) for the 50- to 59-year age group, 0.17% (95% CI, 0-0.50) for the 60- to 69-year age group, 0.45% (95% CI, 0.09-0.81) for the 70- to 79-year age group, and 0.58% (95% CI, 0-1.29) for the 80- to 89-year age group. The sex-adjusted prevalence was 0.41% (95% CI, 0-1.00) for women and 0.51% (95% CI, 0-1.07) for men. Observed frequencies were similar in men and women, with a slight male predominance. Of the 12 participants with CCM, 9 (75%) had a single Zabramski type 2 lesion in a supratentorial location. Only 1 participant (0.037%) was symptomatic from the CCM during the study period.

Conclusions and Relevance

The findings and data from this study are important for determining the potential number of patients available for cohort studies and anticipated clinical trials in older patients with CCM.

Development of cystic malacia after high-dose cranial irradiation of pediatric CNS tumors in long-term follow-up

PURPOSE

The purpose of this study is to investigate the incidence of cystic malacia in long-term survivors of pediatric brain tumors treated with high-dose cranial irradiation.

MATERIALS AND METHODS

Between 1997 and 2015, we treated 41 pediatric patients (26 males, 15 females; age ranging from 3.3 to 15.7 years, median 9-year-old) of pediatric brain tumors [17 medulloblastomas, 7 primitive neuroectodermal tumors (PNET), 3 pineoblastomas, 6 non-germinomatous germ cell tumors (NGGCT), 8 gliomas (including 4 ependymomas, 1 anaplastic astrocytoma, 1 oligodendroglioma, 1 pilocytic astrocytoma, 1 astroblastoma)] with high-dose craniospinal irradiation. Follow-up ranged from 14.0 to 189.2 months (median 86.0 months, mean 81.5 months), the irradiation dose to the whole neural axis ranged from 18 to 41.4 Gy, and the total local dose from 43.2 to 60.4 Gy. All patients underwent follow-up magnetic resonance imaging (MRI) studies at least once a year. Diagnosis of cystic malacia was based solely on MRI findings. Of the 41 patients, 31 were censored during their follow-up due to recurrence of the primary disease (n = 5), detection of secondary leukemia after development of cystic malacia (n = 1), or the absence of cystic malacia on the last follow-up MRI study (n = 25). We also evaluated the development of post-irradiation cavernous angioma and white matter changes.

RESULTS

Following irradiation treatment, 11 patients developed 19 cystic malacia during a median course of 30.8 months (range 14.9 to 59.3 months). The site of predilection for cystic malacia was white matter around trigone of lateral ventricles with an incidence of 47.4% (9 of 19 lesions, 7 in 11 patients). Patients with supratentorial tumors developed cystic malacia statistically earlier than the patients with infratentorial tumors (P = 0.0178, log-rank test). Among the same patient group, incidence of post-irradiation cavernous angioma increased progressively, while the incidence of post-irradiation cystic malacia did not increase after 5 years. White matter degeneration developed earlier than cystic malacia or cavernous angioma, and these three clinical entities developed mutually exclusive of each other.

CONCLUSION

We attribute the higher incidence of post-irradiation cystic malacia, in our long-term follow-up study, to the cranial irradiation for pediatric brain tumors, particularly supratentorial brain tumors, and recommend a regular, long-term follow-up of brain tumor patients treated with cranial irradiation.

Awad I, Dahlem K, Flemming K, Hart B, Kim H, Jusue-Torres I, Kondziolka D, Lee C, Morrison L, Rigamonti D, Rebeiz T, Tournier-Lasserve E, Waggoner D, Whitehead K. Synopsis of Guidelines for the Clinical Management of Cerebral Cavernous Malformations: Consensus Recommendations Based on Systematic Literature Review by the Angioma Alliance Scientific Advisory Board Clinical Experts Panel

BACKGROUND

Despite many publications about cerebral cavernous malformations (CCMs), controversy remains regarding diagnostic and management strategies.

OBJECTIVE

To develop guidelines for CCM management.

METHODS

The Angioma Alliance ( www.angioma.org ), the patient support group in the United States advocating on behalf of patients and research in CCM, convened a multidisciplinary writing group comprising expert CCM clinicians to help summarize the existing literature related to the clinical care of CCM, focusing on 5 topics: (1) epidemiology and natural history, (2) genetic testing and counseling, (3) diagnostic criteria and radiology standards, (4) neurosurgical considerations, and (5) neurological considerations. The group reviewed literature, rated evidence, developed recommendations, and established consensus, controversies, and knowledge gaps according to a prespecified protocol.

RESULTS

Of 1270 publications published between January 1, 1983 and September 31, 2014, we selected 98 based on methodological criteria, and identified 38 additional recent or relevant publications. Topic authors used these publications to summarize current knowledge and arrive at 23 consensus management recommendations, which we rated by class (size of effect) and level (estimate of certainty) according to the American Heart Association/American Stroke Association criteria. No recommendation was level A (because of the absence of randomized controlled trials), 11 (48%) were level B, and 12 (52%) were level C. Recommendations were class I in 8 (35%), class II in 10 (43%), and class III in 5 (22%).

CONCLUSION

Current evidence supports recommendations for the management of CCM, but their generally low levels and classes mandate further research to better inform clinical practice and update these recommendations. The complete recommendations document, including the criteria for selecting reference citations, a more detailed justification of the respective recommendations, and a summary of controversies and knowledge gaps, was similarly peer reviewed and is available on line www.angioma.org/CCMGuidelines .

Hemorrhage from cerebral cavernous malformations: a systematic pooled analysis

OBJECTIVE

The aim of this paper is to define an overall cavernous malformation (CM) hemorrhage rate and risk factors for hemorrhage.

METHODS

The authors performed a systematic, pooled analysis via the PubMed database through October 2015 using the terms “cavernoma,” “cavernous malformation,” “natural history,” “bleeding,” and “hemorrhage.” English-language studies providing annual rates and/or risk factors for CM hemorrhage were included. Data extraction, performed independently by the authors, included demographic data, hemorrhage rates, and hemorrhage risk factors.

RESULTS

Across 12 natural history studies with 1610 patients, the mean age at presentation was 42.7 years old and 52% of patients (95% CI 49%–55%) were female. Presentation modality was seizure in 30% (95% CI 25%–35%), hemorrhage in 26% (95% CI 17%–37%), incidental in 17% (95% CI 9%–31%), and focal deficits only in 16% of cases (95% CI 11%–23%). CM location was lobar in 66% (95% CI 61%–70%), brainstem in 18% (95% CI 13%–24%), deep supratentorial in 8% (95% CI 6%–10%), and cerebellar in 8% (95% CI 5%–11%). Pooling 7 studies that did not assume CM presence since birth, the annual hemorrhage rate was 2.5% per patient-year over 5081.2 patient-years of follow-up (95% CI 1.3%–5.1%). Pooling hazard ratios across 5 studies that evaluated hemorrhage risk factors, prior CM hemorrhage was a significant risk factor for hemorrhage (HR 3.73, 95% CI 1.26–11.1; p = 0.02) while younger age, female sex, deep location, size, multiplicity, and associated developmental venous anomalies (DVAs) were not.

CONCLUSIONS

Although limited by the heterogeneity of incorporated reports and selection bias, this study found prior hemorrhage to be a significant risk factor for CM bleeding, while age, sex, CM location, size, multiplicity, and associated DVAs were not. Future natural history studies should compound annual hemorrhage rate with prospective seizure and nonhemorrhagic neurological deficit rates.

A novel CCM2 variant in a family with non-progressive cognitive complaints and cerebral microbleeds

Lobar cerebral microbleeds are most often sporadic and associated with Alzheimer's disease. The aim of our study was to identify the underlying genetic defect in a family with cognitive complaints and multiple lobar microbleeds and a positive family history for early onset Alzheimer's disease. We performed exome sequencing followed by Sanger sequencing for validation purposes on genomic DNA of three siblings with cognitive complaints, reduced amyloid-beta-42 in CSF and multiple cerebral lobar microbleeds. We checked for the occurrence of the variant in a cohort of 363 patients with early onset dementia and/or microbleeds. A novel frameshift variant (c.236_237delAC) generating a premature stop codon in the CCM2 gene shared by all three siblings was identified. Pathogenicity of the variant was supported by the presence of cerebral cavernous malformations in two of the siblings and by the absence of the variant exome variant databases. Two siblings were homozygous for APOE-ϵ4; one heterozygous. The cognitive complaints, reduced amyloid-beta-42 in CSF and microbleeds suggest preclinical Alzheimer's disease, but the stability of the cognitive complaints does not. We hypothesize that the phenotype in this family may be due to a combination of the CCM2 variant and the APOE status. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Familial Cerebral Cavernous Malformations Are Associated with Adrenal Calcifications on CT Scans: An Imaging Biomarker for a Hereditary Cerebrovascular Condition

Purpose To determine if adrenal calcifications seen at computed tomography (CT) are associated with familial cerebral cavernous malformations (fCCMs) in carriers of the CCM1 Common Hispanic Mutation. Materials and Methods This study was approved by the institutional review board. The authors retrospectively reviewed abdominal CT scans in 38 patients with fCCM, 38 unaffected age- and sex-matched control subjects, and 13 patients with sporadic, nonfamilial cerebral cavernous malformation (CCM). The size, number, and laterality of calcifications and the morphologic characteristics of the adrenal gland were recorded. Brain lesion count was recorded from brain magnetic resonance (MR) imaging in patients with fCCM. The prevalence of adrenal calcifications in patients with fCCM was compared with that in unaffected control subjects and those with sporadic CCM by using the Fisher exact test. Additional analyses were performed to determine whether age and brain lesion count were associated with adrenal findings in patients with fCCM. Results Small focal calcifications (SFCs) (≤5 mm) were seen in one or both adrenal glands in 19 of the 38 patients with fCCM (50%), compared with 0 of the 38 unaffected control subjects (P < .001) and 0 of the 13 subjects with sporadic CCM (P = .001). Adrenal calcifications in patients with fCCM were more frequently left sided, with 17 of 19 patients having more SFCs in the left adrenal gland than the right adrenal gland and 50 of the 61 observed SFCs (82%) found in the left adrenal gland. No subjects had SFCs on the right side only. In patients with fCCM, the presence of SFCs showed a positive correlation with age (P < .001) and number of brain lesions (P < .001). Conclusion Adrenal calcifications identified on CT scans are common in patients with fCCM and may be a clinically silent manifestation of disease. ^© RSNA, 2017.

Post-irradiation lumbosacral radiculopathy associated with multiple cavernous malformations of the cauda equina: Case report and review of the literature

BACKGROUND

Multiple radiation-induced cavernous malformations of the cauda equina are extremely rare. A review of the literature suggested that the post-irradiation lumbosacral radiculopathy in our patient was most likely associated with a diagnosis of multiple radiation-induced cavernous malformations of the cauda equina.

CASE DESCRIPTION

A 76-year-old man with a remote history of abdominal radiation therapy presented with a 6-month history of progressively worsening right foot drop and balance impairment. Magnetic resonance imaging (MRI) revealed multiple enhancing areas of the cauda equina concerning for carcinomatous meningitis, however, cerebrospinal fluid (CSF) analysis was unrevealing. Intraoperative findings were consistent with multiple radiation-induced cavernous malformations of the cauda equina.

CONCLUSIONS

Multiple radiation-induced cavernous malformations of the cauda equina may mimic carcinomatous or infectious meningitis. Clinicians should be suspicious of this diagnosis when CSF and MRI findings are inconsistent with metastatic disease or infectious meningitis in patients who present with radiculopathy and a history of radiation therapy.

[Clinical magnetic resonance imaging : Frequent incidental cerebral findings]

The increasing use of magnetic resonance imaging (MRI) in clinical diagnostics means that patients and physicians are confronted more often with incidental findings. In the literature there are fluctuating data on the incidence of such findings and guidelines concerning the further procedure exist in only very few cases, such as incidental aneurysms and pituitary adenomas. The diagnostic and therapeutic implications which can be derived from incidental findings depend on multiple factors, such as anatomical location, patient age, comorbidity and patient wishes. For this reason it often makes sense to refer patients with incidental findings to an interdisciplinary neurological center at an early stage. In this review frequent incidental cerebral findings, epidemiological data, imaging criteria and, where possible, recommendations for the further procedure are shown.

Rare case of vascular malformations in both skin and brain: Case report and published work review

Solitary venous malformation (VM) of the skin, previously known as cavernous hemangioma, is frequently observed in the dermatological field, but multiple acquired VM are rare. We present a case of multiple VM of the skin associated with multiple cerebral cavernous malformations (CCM) in a 70-year-old Japanese woman. In addition, we summarize seven reported similar cases, including the present case. That some reports have described concomitant VM of the skin and CCM, together with the present case, suggests a tight relationship or a common pathogenetic pathway between these two diseases.

A Novel CCM1/KRIT1 Heterozygous Nonsense Mutation (c.1864C>T) Associated with Familial Cerebral Cavernous Malformation: a Genetic Insight from an 8-Year Continuous Observational Study

Cerebral cavernous malformation (CCM) is a congenital vascular abnormality that predominantly affects the central nervous system, but that sometimes encroaches other vital tissues, including the retina, skin, and even liver. The familial form of CCM (FCCM) is considered to be an autosomal dominant disease with incomplete penetrance and variable expression, which is often attributed to mutations in three genes: CCM1, CCM2, and CCM3. We screened a Chinese family diagnosed with FCCM by using Sanger sequencing. A 29-year-old male proband with cutaneous angiomas was pathologically diagnosed but presented with an atypical form of CCM as revealed by magnetic resonance imaging (MRI) findings, prompting further clinical evaluation and genetic analyses of him and his immediate family. We performed continuous observation over an 8-year period using MRI gradient echo imaging and susceptibility-weighted imaging of these individuals. Sanger sequencing of the CCM1, CCM2, and CCM3 genes identified a novel heterozygous nonsense nucleotide transition (c.1864C>T; p.Gln622X) in exon 17 of the CCM1/KRIT1 gene; this mutation was predicted to cause a premature stop codon (TAG) at nucleotides 1864 to 1866 to generate a truncated Krev interaction trapped 1 (Krit1) protein of 621 amino acids. During this long-term observational study, one of the enrolled family members with neurological deficits progressed to a stage indicative of brain surgery. This study provides a new CCM gene mutation profile, which highlights the significance of genetic counseling for individuals suspected of having this condition.

Periodic Lateralized Epileptiform Discharges can Survive Anesthesia and Result in Asymmetric Drug-induced Burst Suppression

Drug-induced burst suppression (DIBS) is bihemispheric and bisymmetric in adults and older children. However, asymmetric DIBS may occur if a pathological process is affecting one hemisphere only or both hemispheres disproportionately. The usual suspect is a destructive lesion; an irritative or epileptogenic lesion is usually not invoked to explain DIBS asymmetry. We report the case of a 66-year-old woman with new-onset seizures who was found to have a hemorrhagic cavernoma and periodic lateralized epileptiform discharges (PLEDs) in the right temporal region. After levetiracetam and before anesthetic antiepileptic drugs (AEDs) were administered, the electroencephalogram (EEG) showed continuous PLEDs over the right hemisphere with maximum voltage in the posterior temporal region. Focal electrographic seizures also occurred occasionally in the same location. Propofol resulted in bihemispheric, but not in bisymmetric, DIBS. Remnants or fragments of PLEDs that survived anesthesia increased the amplitude and complexity of the bursts in the right hemisphere leading to asymmetric DIBS. Phenytoin, lacosamide, ketamine, midazolam, and topiramate were administered at various times in the course of EEG monitoring, resulting in suppression of seizures but not of PLEDs. Ketamine and midazolam reduced the rate, amplitude, and complexity of PLEDs but only after producing substantial attenuation of all burst components. When all anesthetics were discontinued, the EEG reverted to the original preanesthesia pattern with continuous non-fragmented PLEDs. The fact that PLEDs can survive anesthesia and affect DIBS symmetry is a testament to the robustness of the neurodynamic processes underlying PLEDs.

Co-expression of tissue factor and IL-6 in immature endothelial cells of cerebral cavernous malformations

Cerebral cavernous malformations (CCMs) are congenital abnormal clusters of capillaries that are prone to leaking and thought to result from a disorder of endothelial cells. The underlying pathology of CCM is not fully understood. We analyzed the expression of tissue factor (TF) and interleukin-6 (IL-6) in CCMs to determine the association of TF and IL-6 with clinical and pathological findings. Thirteen cases of operative specimens of sporadic CCMs were included in this study. The expression of messenger RNA of TF and IL-6 was assayed and the association with clinical factors was investigated. Then, the distribution of TF and IL-6 was examined with immunofluorescence. The mRNA expression of TF of CCMs was significantly higher than that of the control (p=0.017), and was correlated with the number of hemorrhage appearances (p=0.190, ρ=0.62). The mRNA expression level of IL-6 was significantly correlated with the mRNA expression level of TF (p=0.034, ρ=0.58). Examination of immunostained sections indicated that TF⁺ cells were also positive for IL-6, and distributed around normal endothelial cells. Moreover, the TF⁺/IL-6⁺ cells expressed CD31 and VEGFR2. The expressions of IL-6 and TF were correlated, and both were present in the same immature endothelial cells. TF is elevated in CCM and might mediate progressive events. These factors may play a prognostic role in CCM.

Epidemiology of cavernous malformations

Cavernous malformations, accounting for approximately 5-15% of all vascular abnormalities in the central nervous system, are angiographically occult lesions which most often present with seizures, rather than acute hemorrhage. Widely variable across populations, the incidence of cavernous malformations has been reported to be 0.15-0.56 per 100 000 persons per year, with an annual hemorrhage rate of 0.6-11% per patient-year. Seen in 0.17-0.9% of the population, up to one-half are familial, and at least three gene loci have been associated with a familial form, more common among Hispanic Americans. Most cavernous malformations are supratentorial, with 10-23% in the posterior fossa, and approximately 5% found in the spine.

Thalamic cavernous malformations

Cavernous malformations of the thalamus represent a particularly complex subset of cavernous malformations because of the highly eloquent nature of the involved tissue and their deep location. The decision about whether to operate on any individual lesion depends on the specific location of the lesion within the thalamus, the nature of the patient's symptoms, and the patient's history. When surgery is recommended, the approach must be chosen carefully. Each part of the thalamus is reached by a different surgical approach. These approaches include the orbitozygomatic approach to the anteroinferior thalamus, the anterior interhemispheric transcallosal approach to the medial thalamus, the anterior contralateral interhemispheric transcallosal approach to the lateral thalamus, the posterior interhemispheric transcallosal approach to the posterosuperior thalamus, the parieto-occipital transventricular approach to the lateral posteroinferior thalamus, and the suboccipital supracerebellar infratentorial/transtentorial approach to the medial posteroinferior thalamus. Careful attention to safe entry zones and image guidance can allow safe removal of these lesions when necessary.

Radiology and imaging for cavernous malformations

Cavernous malformations are low-flow vascular malformations that are histologically characterized by the lack of mural elements of mature vascular structures and intervening parenchymal neural tissue. They are often clinically quiescent, and may grow, bleed, and regress, but can also manifest clinically as neurologic deficits or seizures in the setting of an acute hemorrhage. The low-flow nature of cavernous malformations renders them inherently occult on cerebral angiography. Magnetic resonance imaging has become the mainstay imaging modality in evaluating cavernous malformations, producing characteristic imaging features that usually provide a straightforward diagnosis. Features on magnetic resonance imaging include a reticulated pattern of mixed hyper- and hypointensity on T1- and T2-weighted imaging, with a characteristic hypointense rim best appreciated on T2-weighted imaging or gradient-echo sequences. Contrast enhancement is useful for revealing coexisting developmental venous anomalies that are frequently associated with sporadic cavernous malformations, and may further support the diagnosis. Susceptibility-weighted imaging is highly sensitive for cavernous malformations and accompanying developmental venous anomalies, and is superior to gradient-echo sequences in screening for multifocal, familial cavernous malformations.

Natural history of cerebral cavernous malformations

Cerebral cavernous malformations (CCM) are vascular abnormalities of the central nervous system with an incidence of 0.4-0.5% and an annual rate of hemorrhage ranging from 0.7% to 1%. Most lesions are located in the cerebral hemisphere but some occur in deeper locations such as the basal ganglia and pons. The most common symptoms during presentation are headache, seizures, and focal neurologic deficits. Surgery remains the most effective treatment modality for symptomatic CCM, while the management of incidental CCM remains controversial. Factors associated with increased risk of hemorrhage include being female and less than 40 years old. This finding, however, is not consistent in all natural history studies evaluated. During follow-up, the most important and consistent risk factor for rebleed was a prior hemorrhage. Here, we provide an indepth but concise review of the literature regarding the natural history of CCMs.

Natural history of spinal cavernous malformations

Spinal cavernous malformations are intramedullary vascular lesions. They have low pressure and flow, so they may take many years to present with clinical symptoms. Because of their relatively benign nature, surgical intervention is not always indicated. An understanding of the natural history of cavernous malformations helps make decisions about when and if to intervene. In patients who do not have surgery, 88.7% have stable or improved neurologic function, whereas 89.3% have these outcomes in the surgical group. Of note, 51.5% of patients were found to improve in the surgical group, compared to 30.2% in the nonsurgical group. Characteristics that correlated with better neurologic outcome were: resection within 3 months of the onset of symptoms, gross total resection, presentation with motor symptoms, and an acute course. Sensory symptoms correlated with worse outcome. Given the natural history of spinal cavernous malformations, surgery may be considered for symptomatic patients, when general medical health and lesion location permit safe resection. The severity of symptoms must also be considered, as the natural history of the disease can be benign.

Supratentorial cavernous malformations

Supratentorial cavernous malformations are uncommon cerebral vascular lesions that may present many unique challenges for treating physicians. The vast majority will be discovered during workup for seizures or after symptomatic intracerebral hemorrhage. Supratentorial cavernous malformations are increasingly being discovered incidentally in patients who obtain brain imaging for unrelated reasons. Management strategies including watchful waiting, antiepileptic drug therapy, microsurgery, or an expanding array of "minimally invasive" therapies. Thus, clinical decision making is not always straightforward and a nuanced approach tempered by experience and good judgment is critical to achieving excellent clinical results.

Pathology of cavernous malformations

Cavernous malformations (CMs) are low-pressure angiographically occult lesions, composed of blood-filled sinusoidal locules known as "caverns." Although these lesions were once believed to be congenital in nature, there is compelling evidence to support de novo formation of CMs as well. They can occur as sporadic lesions or be inherited in an autosomal-dominant phenotype in familial forms of the disease. The pathophysiology of CMs is commonly believed to be due to abnormal vascular pathology. Three genes, CCM1, CCM2, and CCM3, have been extensively studied for their role in vascular pathology, resulting in abnormal angiogenesis and compromising the structural integrity of vessel endothelial cell. The expression of growth factors has been researched to gain insight into the dynamic behavior of CM lesions. Gross and microscopic images are utilized in this chapter to illustrate the pathologic findings of these lesions. Ultrastructural analysis demonstrates the aberrations in CM endothelial cells and structural integrity that may provide better understanding into how and why these lesions have a propensity to hemorrhage.

Microbleeds and cavernomas after radiotherapy for paediatric primary brain tumours

BACKGROUND

With the expected growth and aging of the population of primary central nervous system tumours (PCNST) survivors, attention to the radiation-induced late brain injury is fundamental. Late focal hemosiderin deposition (FHD) lesions, namely microbleeds and cavernomas, are among the presumable late cerebrovascular complications associated with radiotherapy for PCNST.

OBJECTIVE

To explore association between PCNST radiotherapy and the occurrence FHD lesions and to address the correlation between the topographic location of these microvascular lesions with the focal radiotherapy location.

METHODS

Retrospective cohort study of 190 paediatric patients being followed for PCNST in a single referral oncological centre. The frequency of FHD lesions was compared between paediatric PCNST treated (n=132) and not treated (n=58) with brain radiation. Microbleed Anatomical Rating Scale (MARS) was used for systematic identification of these cerebrovascular lesions and to address the consistency between the topographic location of each lesion and the location of the focal radiotherapy area. Univariate analysis to address the role of variables such as tumour histology, location, gender and age of children at the beginning of radiotherapy, duration of follow-up and chemotherapy was performed.

RESULTS

FHD lesions (microbleeds and cavernomas) occurred exclusively and in a high percentage (41.6%) in PCNST survivors treated with brain radiation. Younger age at the diagnosis (p=0.031), duration of follow-up (p=0.010) and embryonal histology (p=0.003) positively correlated with the occurrence FHD lesions. FHD lesions were topographically concordant with the brain focal irradiation area in 3/19 (15.8%) patients from the focal RT subgroup and in 22/111 (19.8%) patients from the WBRT plus focal RT subgroup.

CONCLUSION

Our study, which is one of the largest to date on the topic, shows that FHD lesions are a common complication after radiotherapy for childhood PCNST. The young brain is probably more susceptible to radiation-induced late cerebrovascular injury. Diffuse small vessel disease and ceiling effect may account for the low topographic concordance we found. The clinical implications of FHD lesions in this specific population are yet to be clarified.