Sturge-Weber Syndrome: Brain Magnetic Resonance Imaging and Neuropathology Findings

Radio-pathologic correlation: no pial angioma-subarachnoid varicose network drainage pathway in Sturge-Weber syndrome

PURPOSE

The traditional imaging findings reported in Sturge-Weber syndrome (SWS) include endpoints of cortical injury-cortical atrophy and cortical calcifications-but also what has been termed a "leptomeningeal angiomatosis," the latter recognized and reported as a leptomeningeal enhancement on magnetic resonance imaging (MRI). The objective of this study is to demonstrate through neuropathological correlation that the "leptomeningeal angiomatosis" in patients with Sturge-Weber syndrome (SWS), represents a re-opened primitive venous network in the subarachnoid space that likely acts as an alternative venous drainage pathway, seen separately to abnormal pial enhancement.

MATERIALS AND METHODS

Retrospective review of MR imaging and surgical pathology of patients that underwent surgery for epilepsy at a tertiary, children's hospital. A pediatric radiologist with more than 20 years of experience reviewed the MR imaging. Surgically resected brain specimens that had been sectioned and fixed in 10% paraformaldehyde for histologic processing, following processing and paraffin embedding, were cut into 5-µm unstained slides which were subsequently stained with hematoxylin and eosin (H&E). Slides were re-examined by a board-certified pediatric neuropathologist, and histologic features specifically relating to cerebral surface and vascularity were documented for correlation with MR imaging of the resected region performed prior to resection.

RESULTS

Five patients were reviewed (3 boys and 2 girls; the median age at the onset of seizures was 12 months (IQR, 7 to 45 months); the median age at surgery was 33 months (IQR, 23.5 to 56.5 months)). Surgical procedures included the following: 4, hemispherotomy (right: 2, left: 2) and 1, hemispherectomy (right). A subarachnoid space varicose network was present on both MRI and histology in 4 patients. Calcifications were seen on both MRI and histology in 3 patients. Abnormal leptomeningeal enhancement was present in 5 patients and seen separately from the subarachnoid vascular network in 4 patients.

CONCLUSION

Histopathology confirmed the MRI findings of a subarachnoid space varicose network seen separately from leptomeningeal enhancement and presumed to represent an alternative venous drainage pathway to compensate for maldevelopment of cortical veins, the primary abnormality in SWS. No pial-based angioma was identified.

Feasibility and Potential Diagnostic Value of Noncontrast Brain MRI in Nonsedated Children With Sturge-Weber Syndrome and Healthy Siblings

BACKGROUND

Postcontrast magnetic resonance imaging (MRI), obtained under anesthesia, is often used to evaluate brain parenchymal and vascular abnormalities in young children, including those with Sturge-Weber syndrome. However, anesthesia and contrast administration may carry risks. We explored the feasibility and potential diagnostic value of a noncontrast, nonsedate MRI acquisition in Sturge-Weber syndrome children and their siblings with a wide range of cognitive and behavioral functioning.

METHODS

Twenty children (10 with Sturge-Weber syndrome and 10 healthy siblings; age: 0.7-13.5 years) underwent nonsedate 3-tesla (T) brain MRI acquisition with noncontrast sequences (including susceptibility-weighted imaging) prospectively along with neuropsychology assessment. All images were evaluated for quality, and MRI abnormalities identified in the Sturge-Weber syndrome group were compared to those identified on previous clinical pre- and postcontrast MRI.

RESULTS

Nineteen participants (95%) completed the MRI with good (n = 18) or adequate (n = 1) quality, including all children with Sturge-Weber syndrome and all 5 children ≤5 years of age. The Sturge-Weber syndrome group had lower cognitive functions than the controls, and both groups had several children with behavioral issues, without an apparent effect on the success and quality of the MR images. Susceptibility-weighted imaging detected key venous vascular abnormalities and calcifications and, along with the other noncontrast sequences, provided diagnostic information comparable to previous clinical MRI performed with contrast administration under anesthesia.

CONCLUSION

This study demonstrates the feasibility and the potential diagnostic value of a nonsedate, noncontrast MRI acquisition protocol in young children including those with cognitive impairment and/or behavioral concerns. This approach can facilitate clinical trials in children where safe serial MRI is warranted.

Seizure, Motor, and Cognitive Outcomes After Epilepsy Surgery for Patients With Sturge-Weber Syndrome: Results From a Multicenter Study

BACKGROUND AND OBJECTIVES

Surgery is widely performed for refractory epilepsy in patients with Sturge-Weber syndrome (SWS), but reports on its effectiveness are limited. This study aimed to analyze seizure, motor, and cognitive outcomes of surgery in these patients and to identify factors associated with the outcomes.

METHODS

This was a multicenter retrospective observational study using data from patients with SWS and refractory epilepsy who underwent epilepsy surgery between 2000 and 2020 at 16 centers throughout China. Longitudinal postoperative seizures were classified by Engel class, and Engel class I was regarded as seizure-free outcome. Functional (motor and cognitive) outcomes were evaluated using the SWS neurologic score, and improved or unchanged scores between baseline and follow-up were considered to have stable outcomes. Outcomes were analyzed using Kaplan-Meier analyses. Multivariate Cox regression was used to identify factors associated with outcomes.

RESULTS

A total of 214 patients with a median age of 2.0 (interquartile range 1.2-4.6) years underwent surgery (focal resection, FR [n = 87]; hemisphere surgery, HS [n = 127]) and completed a median of 3.5 (1.7-5.0) years of follow-up. The overall estimated probability for being seizure-free postoperatively at 1, 2, and 5 years was 86.9% (95% CI 82.5-91.6), 81.4% (95% CI 76.1-87.1), and 70.7% (95% CI 63.3-79.0), respectively. The overall estimated probability of being motor stable at the same time post operatively was 65.4% (95% CI 58.4-71.2), 80.2% (95% CI 73.8-85.0), and 85.7% (95% CI 79.5-90.1), respectively. The overall probability for being cognition stable at 1, 2, and 5 years was 80.8% (95% CI 74.8-85.5), 85.1% (95% CI 79.3-89.2), and 89.5% (95% CI 83.8-93.2), respectively. Both FR and HS were effective at ensuring seizure control. For different HS techniques, modified hemispherotomy had comparable outcomes but improved safety compared with anatomical hemispherectomy. Regarding FR, partial resection (adjusted hazard ratio [aHR] 11.50, 95% CI 4.44-29.76), acute postoperative seizure (APOS, within 30 days of surgery; aHR 10.33, 95% CI 3.94-27.12), and generalized seizure (aHR 3.09, 95% CI 1.37-6.94) were associated with seizure persistence. For HS, seizure persistence was associated with APOS (aHR 27.61, 9.92-76.89), generalized seizure (aHR 7.95, 2.74-23.05), seizure frequency ≥30 times/month (aHR 4.76, 1.27-17.87), and surgical age ≥2 years (aHR 3.78, 1.51-9.47); motor stability was associated with severe motor defects (aHR 5.23, 2.27-12.05) and postoperative seizure-free status (aHR 3.09, 1.49-6.45); and cognition stability was associated with postoperative seizure-free status (aHR 2.84, 1.39-5.78) and surgical age <2 years (aHR 1.76, 1.13-2.75).

DISCUSSION

FR is a valid option for refractory epilepsy in patients with SWS and has similar outcomes to those of HS, with less morbidity associated with refractory epilepsy. Early surgical treatment (under the age of 2 years) leads to better outcomes after HS, but there is insufficient evidence that surgical age affects FR outcomes. These findings warrant future prospective multicenter cohorts with international cooperation and prolonged follow-up in better exploring more precise outcomes and developing prognostic predictive models.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that in children with SWS and refractory seizures, surgical resection-focal, hemispherectomy, or modified hemispherotomy-leads to improved outcomes.

Sturge-Weber syndrome: an update for the pediatrician

BACKGROUND

Sturge-Weber syndrome (SWS) is a rare congenital neurocutaneous disorder characterized by the simultaneous presence of both cutaneous and extracutaneous capillary malformations. SWS usually presents as a facial port-wine birthmark, with a varying presence of leptomeningeal capillary malformations and ocular vascular abnormalities. The latter may lead to significant neurological and ocular morbidity such as epilepsy and glaucoma. SWS is most often caused by a somatic mutation involving the G protein subunit alpha Q or G protein subunit alpha 11 gene causing various alterations in downstream signaling pathways. We specifically conducted a comprehensive review focusing on the current knowledge of clinical practices, the latest pathophysiological insights, and the potential novel therapeutic avenues they provide.

DATA SOURCES

A narrative, non-systematic review of the literature was conducted, combining expert opinion with a balanced review of the available literature. A search of PubMed, Google Scholar and Embase was conducted, using keywords "Sturge-Weber Syndrome" OR "SWS", "Capillary malformations", "G protein subunit alpha 11" OR "G protein subunit alpha Q".

RESULTS

One of the hallmark features of SWS is the presence of a port-wine birthmark at birth, and forehead involvement is most indicative for SWS. The most common ocular manifestations of SWS are glaucoma and choroidal hemangioma. Glaucoma presents in either in infancy (0-3 years of age) or later in life. Neurological complications are common in SWS, occurring in about 70%-80% of patients, with seizures being the most common one. SWS significantly impacts the quality of life for patients and their families, and requires a multidisciplinary approach for diagnosis and treatment. Currently, no disease-modifying therapies exist, and treatment is mostly focused on symptoms or complications as they arise.  CONCLUSIONS: SWS remains a complex and heterogeneous disorder. Further research is needed to optimize diagnostic and therapeutic strategies, and to translate insights from molecular pathogenesis to clinical practice.

The natural history of epilepsy and nonepileptic seizures in Sturge-Weber syndrome: A retrospective case-note review

OBJECTIVE

Patients with Sturge-Weber Syndrome (SWS) experience varying degrees of neurological problems - including epilepsy, hemiparesis, learning disability (LD), and stroke-like episodes. While the range of clinical problems experienced by children with SWS is well recognized, the spectrum of clinical presentation and its treatment during adulthood has been relatively neglected in the literature to date. This study explored the natural history of epileptic and nonepileptic seizures into adulthood in patients with SWS, and their treatment, and investigated whether any clinical factors predict which symptoms a patient will experience during adulthood.

METHODS

A retrospective case-note review of a cohort of 26 adults with SWS at the National Hospital for Neurology and Neurosurgery (NHNN). Childhood data were also recorded, where available, to enable review of change/development of symptoms over time.

RESULTS

The course of epilepsy showed some improvement in adulthood - seventeen adults continued to have seizures, while six patients gained seizure freedom, and no one had adult-onset seizures. However, seizures did worsen for some patients. Although no factors reached statistical significance regarding predicting continued epilepsy in adulthood, being male, more severe LD, having required epilepsy surgery, and bilateral cortical involvement may be important. Nonepileptic seizures (NES) also began during adulthood for four patients.

SIGNIFICANCE

By adulthood, there is some degree of improvement in epilepsy overall; while NES may occur for the first time. While the majority of the results did not survive adjustments for multiple comparisons, some interesting trends appeared, which require further investigation in a multicenter national audit. Patients with more neurologically severe presentations during childhood may continue to experience seizures. Careful monitoring and screening are needed during adulthood, to detect changes and newly developing symptoms such as NES, and target treatment promptly.

Seizure outcomes in children with Sturge-Weber syndrome undergoing epilepsy surgery: An individual participant data meta-analysis

BACKGROUND

A subpopulation of patients with Sturge-Weber syndrome (SWS) develop medically intractable epilepsy. There is a paucity of literature on preoperative factors that predict postoperative seizure outcomes in these patients. An individual participant data meta-analysis (IPDMA) was performed to discern preoperative variables associated with favorable seizure outcomes in pediatric SWS patients undergoing epilepsy surgery.

METHODS

PubMed, Cochrane, Web of Science, and Scopus were independently queried following PRISMA guidelines. Studies that reported seizure outcomes in individual pediatric SWS patients were selected. Preoperative demographic variables and disease characteristics were recorded and evaluated in a time-to-event fashion via Cox regression and Kaplan-Meier analysis with log-rank test.

RESULTS

A total of 18 studies with 108 patients were included for meta-analysis. Median age at seizure onset was 4.5 months, and 85 patients (78.7%) were seizure-free at last follow-up (median: 72 months). On multivariable Cox regression, no variables were independent predictors of post-operative seizure freedom duration, including the extent of hemispheric resection. There were also no differences in time-to-seizure recurrence on Kaplan-Meier analysis when comparing those treated with hemispheric surgery and those with less than hemispheric surgery (p = 0.52).

CONCLUSION

This IPDMA showed that both resective and hemispheric epilepsy surgery achieve favorable and comparable seizure outcomes in pediatric SWS patients. The best available evidence using IPD suggests that resective surgery may be an appropriate alternative to hemispheric epilepsy surgery in well-selected patients. Prospective multi-institutional studies with greater follow-up are warranted to further investigate predictors of seizure outcome in pediatric SWS patients.

Neuroimaging in Adults and Children With Epilepsy

OBJECTIVE

This article discusses the fundamental importance of optimal epilepsy imaging using the International League Against Epilepsy-endorsed Harmonized Neuroimaging of Epilepsy Structural Sequences (HARNESS) protocol and the use of multimodality imaging in the evaluation of patients with drug-resistant epilepsy. It outlines a methodical approach to evaluating these images, particularly in the context of clinical information.

LATEST DEVELOPMENTS

Epilepsy imaging is rapidly evolving, and a high-resolution epilepsy protocol MRI is essential in evaluating newly diagnosed, chronic, and drug-resistant epilepsy. The article reviews the spectrum of relevant MRI findings in epilepsy and their clinical significance. Integrating multimodality imaging is a powerful tool in the presurgical evaluation of epilepsy, particularly in "MRI-negative" cases. For example, correlation of clinical phenomenology, video-EEG with positron emission tomography (PET), ictal subtraction single-photon emission computerized tomography (SPECT), magnetoencephalography (MEG), functional MRI, and advanced neuroimaging such as MRI texture analysis and voxel-based morphometry enhances the identification of subtle cortical lesions such as focal cortical dysplasias to optimize epilepsy localization and selection of optimal surgical candidates.

ESSENTIAL POINTS

The neurologist has a unique role in understanding the clinical history and seizure phenomenology, which are the cornerstones of neuroanatomic localization. When integrated with advanced neuroimaging, the clinical context has a profound impact on identifying subtle MRI lesions or finding the "epileptogenic" lesion when multiple lesions are present. Patients with an identified lesion on MRI have a 2.5-fold improved chance of achieving seizure freedom with epilepsy surgery compared with those without a lesion. This clinical-radiographic integration is essential to accurate classification, localization, determination of long-term prognosis for seizure control, and identification of candidates for epilepsy surgery to reduce seizure burden or attain seizure freedom.

ILAE classification and definition of epilepsy syndromes with onset in neonates and infants: Position statement by the ILAE Task Force on Nosology and Definitions

The International League Against Epilepsy (ILAE) Task Force on Nosology and Definitions proposes a classification and definition of epilepsy syndromes in the neonate and infant with seizure onset up to 2 years of age. The incidence of epilepsy is high in this age group and epilepsy is frequently associated with significant comorbidities and mortality. The licensing of syndrome specific antiseizure medications following randomized controlled trials and the development of precision, gene-related therapies are two of the drivers defining the electroclinical phenotypes of syndromes with onset in infancy. The principal aim of this proposal, consistent with the 2017 ILAE Classification of the Epilepsies, is to support epilepsy diagnosis and emphasize the importance of classifying epilepsy in an individual both by syndrome and etiology. For each syndrome, we report epidemiology, clinical course, seizure types, electroencephalography (EEG), neuroimaging, genetics, and differential diagnosis. Syndromes are separated into self-limited syndromes, where there is likely to be spontaneous remission and developmental and epileptic encephalopathies, diseases where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. The emerging class of etiology-specific epilepsy syndromes, where there is a specific etiology for the epilepsy that is associated with a clearly defined, relatively uniform, and distinct clinical phenotype in most affected individuals as well as consistent EEG, neuroimaging, and/or genetic correlates, is presented. The number of etiology-defined syndromes will continue to increase, and these newly described syndromes will in time be incorporated into this classification. The tables summarize mandatory features, cautionary alerts, and exclusionary features for the common syndromes. Guidance is given on the criteria for syndrome diagnosis in resource-limited regions where laboratory confirmation, including EEG, MRI, and genetic testing, might not be available.

Study protocol: retrospectively mining multisite clinical data to presymptomatically predict seizure onset for individual patients with Sturge-Weber

INTRODUCTION

Secondary analysis of hospital-hosted clinical data can save time and cost compared with prospective clinical trials for neuroimaging biomarker development. We present such a study for Sturge-Weber syndrome (SWS), a rare neurovascular disorder that affects 1 in 20 000-50 000 newborns. Children with SWS are at risk for developing neurocognitive deficit by school age. A critical period for early intervention is before 2 years of age, but early diagnostic and prognostic biomarkers are lacking. We aim to retrospectively mine clinical data for SWS at two national centres to develop presymptomatic biomarkers.

METHODS AND ANALYSIS

We will retrospectively collect clinical, MRI and neurocognitive outcome data for patients with SWS who underwent brain MRI before 2 years of age at two national SWS care centres. Expert review of clinical records and MRI quality control will be used to refine the cohort. The merged multisite data will be used to develop algorithms for abnormality detection, lesion-symptom mapping to identify neural substrate and machine learning to predict individual outcomes (presence or absence of seizures) by 2 years of age. Presymptomatic treatment in 0-2 years and before seizure onset may delay or prevent the onset of seizures by 2 years of age, and thereby improve neurocognitive outcomes. The proposed work, if successful, will be one of the largest and most comprehensive multisite databases for the presymptomatic phase of this rare disease.

ETHICS AND DISSEMINATION

This study involves human participants and was approved by Boston Children's Hospital Institutional Review Board: IRB-P00014482 and IRB-P00025916 Johns Hopkins School of Medicine Institutional Review Board: NA_00043846. Participants gave informed consent to participate in the study before taking part. The Institutional Review Boards at Kennedy Krieger Institute and Boston Children's Hospital approval have been obtained at each site to retrospectively study this data. Results will be disseminated by presentations, publication and sharing of algorithms generated.

Characteristics, surgical outcomes, and influential factors of epilepsy in Sturge-Weber syndrome

Few studies have reported the clinical presentation, surgical treatment, outcomes, and influential factors for patients with epilepsy and Sturge-Weber syndrome.

This large-scale retrospective study continuously enrolled 132 patients with Sturge-Weber syndrome and epilepsy from January 2008 to December 2018 at our hospital to analyze their characteristics. Among these patients, 90 underwent epilepsy surgery, and their postoperative 2-year follow-up seizure, cognitive, and motor functional outcomes were assessed and analyzed. Univariable and multivariable logistic analyses were conducted to explore the influential factors.

Among the Sturge-Weber syndrome patients for whom characteristics were analyzed (n = 132), 76.52% of patients had their first epileptic seizures within their first year of life. The risk factors for cognitive decline were seizure history≥2 years (adjusted odds ratio [aOR] = 3.829, 95% confidence interval [CI]: 1.810-9.021, p = 0.008), bilateral leptomeningeal angiomas (aOR = 3.173, 95% CI: 1.970-48.194, p = 0.013), age at onset &lt; 1 year (aOR = 2.903, 95% CI: 1.230-6.514, p = 0.013), brain calcification (aOR = 2.375, 95% CI: 1.396-5.201, p = 0.021) and left leptomeningeal angiomas (aOR = 2.228, 95% CI: 1.351-32.571, p = 0.030). Of the patients who underwent epilepsy surgery (n = 90), 44 were subject to focal resection, and 46 underwent hemisphere surgery (19 anatomical hemispherectomies and 27 modified hemispherotomies). A postoperative seizure-free status, favorable cognitive outcomes, and favorable motor outcomes were achieved in 83.33%, 44.44%, and 43.33% of surgical patients, respectively. The modified hemispherotomy group had similar surgical outcomes, less intraoperative blood loss and shorter postoperative hospital stays than the anatomical hemispherectomy group. Regarding seizure outcomes, full resection (aOR = 11.115, 95% CI: 1.260-98.067, p = 0.020) and age at surgery &lt; 2 years (aOR = 6.040, 95% CI: 1.444-73.367, p = 0.031) were positive influential factors for focal resection. Age at surgery &lt; 2 years (aOR = 15.053, 95% CI: 1.050-215.899, p = 0.036) and infrequent seizures (aOR = 8.426, 95% CI: 1.086-87.442, p = 0.042; monthly vs. weekly) were positive influential factors for hemisphere surgery.

In conclusion, epilepsy surgery resulted in a good postoperative seizure-free rate and favorable cognitive and motor functional outcomes and showed acceptable safety for patients with epilepsy and Sturge-Weber syndrome. Modified hemispherotomy is a less invasive and safer type of hemisphere surgery than traditional anatomic hemispherectomy with similar surgical outcomes. Early surgery may be helpful to achieve better seizure outcomes and cognitive protection, while the risk of surgery for young children should also be considered.

Sturge-Weber syndrome presenting in late adulthood

A 75-year-old woman presents to the acute medical take with confusion and headache following a road traffic accident. She had previously been fit and well, living alone with no assistance. Following multiple investigations, she was diagnosed with Sturge-Weber Syndrome, a rare neurocutaneous disorder that usually presents with seizures in childhood. This case highlights an unusual example of this syndrome, presenting for the first time later in life.

Sturge-Weber syndrome: an update on the relevant issues for neurosurgeons

PURPOSE

Sturge-Weber syndrome (SWS) is a neurocutaneous facomatosis characterized by facial and leptomeningeal angioma, glaucoma, seizures, and neurological disability. Therefore, a challenging multidisciplinary interaction is required for its management. The goal of this paper is to review the main aspects of SWS and to present an illustrative pediatric series.

METHODS

The pertinent literature has been analyzed, focused mainly on etiopathogenesis, pathology, clinical features, diagnostic tools, management, and outcome of the disease. Moreover, a series of 11 children operated on for refractory epilepsy between 2005 and 2015 (minimum follow-up 5 years, mean follow-up 9.6 years) is reported. The series consists of six boys and five girls with 6.5-month and 16.2-month mean age at seizure onset and at surgery, respectively. Seizures affected all children, followed by hemiparesis and psychomotor delay (81%), glaucoma (54%), and other neurological deficits (45%).

RESULTS

All children underwent hemispherectomy (anatomical in three cases, functional in two cases, hemispherotomy in six cases); one patient needed a redo hemispherotomy. Mortality was nil; disseminated intravascular coagulation and interstitial pneumonia occurred in one patient each; three children had subdural fluid collection. Eight patients (72%) are in the ILAE Class 1 (completely seizure and aura free), two in Class 2 (only auras, no seizure), and one in Class 3 (1-3 seizure days per year). AEDs discontinuation was possible in 73% of cases. The most important news from the literature concerned the pathogenesis (role of the mutation of the GNAQ gene in the abnormal SWS vasculogenesis), the clinical findings (the features and pathogenesis of the stroke-like episodes are being understood), the diagnostic tools (quantitative MRI and EEG), and both the medical (migraine, seizures) and surgical management (epilepsy). The epileptic outcome of SWS patients is very good (80% are seizure-free), if compared with other hemispheric syndromes. The quality of life is affected by the neurological and cognitive deficits.

CONCLUSIONS

SWS still is an etiological and clinical challenge. However, the improvements over the time are consistent. In particular, the neurosurgical treatment of refractory epilepsy provides very good results as long as the indication to treatment is correct.

GNA11 brain somatic pathogenic variant in an individual with phacomatosis pigmentovascularis

Objective

To describe the findings of histopathology and genotyping studies in affected brain tissue from an individual with phacomatosis pigmentovascularis (PPV).

Methods

A retrospective chart review of a 2-year 10-month-old male with a clinical diagnosis of PPV cesiomarmorata (or type V) was performed. Clinical features, brain imaging and histopathology findings, and genotyping studies in his affected brain tissue are summarized.

Results

The proband had a clinically severe neurologic phenotype characterized by global developmental delay, generalized hypotonia, and recurrent episodes of cardiac asystole in the setting of status epilepticus. A somatic pathogenic variant in GNA11 (c.547C>T, p.Arg183Cys) was detected in his skin tissue but not in blood (previously published). He underwent an urgent left posterior quadrantectomy for his life-threatening seizures. Histopathology of resected brain tissue showed an increase in leptomeningeal melanocytes and abnormal vasculature, and the exact pathogenic variant in GNA11 (c.547C>T, p.Arg183Cys), previously isolated from his skin tissue but not blood, was detected in his resected brain tissue.

Conclusions

The finding of this variant in affected skin and brain tissue of our patient with PPV supports a unifying genetic diagnosis of his neurocutaneous features.

Neurological Complications of Sturge-Weber Syndrome: Current Status and Unmet Needs

OBJECTIVE

We aimed to identify the current status and major unmet needs in the management of neurological complications in Sturge-Weber syndrome.

METHODS

An expert panel consisting of neurologists convened during the Sturge-Weber Foundation Clinical Care Network conference in September 2018. Literature regarding current treatment strategies for neurological complications was reviewed.

RESULTS

Although strong evidence-based standards are lacking, the implementation of consensus-based standards of care and outcome measures to be shared across all Sturge-Weber Foundation Clinical Care Network Centers are needed. Each patient with Sturge-Weber syndrome should have an individualized seizure action plan. There is a need to determine the appropriate abortive and preventive treatment of migraine headaches in Sturge-Weber syndrome. Likewise, a better understanding and better diagnostic modalities and treatments are needed for stroke-like episodes. As behavioral problems are common, the appropriate screening tools for mental illnesses and the timing for screening should be established. Brain magnetic resonance imaging (MRI) preferably done after age one year is the primary imaging modality of choice to establish the diagnosis, although advances in MRI techniques can improve presymptomatic diagnosis to identify patients eligible for preventive drug trials.

CONCLUSION

We identified the unmet needs in the management of neurological complications in Sturge-Weber syndrome. We define a minimum standard brain MRI protocol to be used by Sturge-Weber syndrome centers. Future multicenter clinical trials on specific treatments of Sturge-Weber syndrome-associated neurological complications are needed. An improved national clinical database is critically needed to understand its natural course, and for retrospective and prospective measures of treatment efficacy.

Restrictive cerebral cortical venopathy: A new clinicopathological entity

We present a case of a novel restrictive cerebral venopathy in a child, consisting of a bilateral network of small to medium cortical veins without evidence of arteriovenous shunting, absence of the deep venous system, venous ischemia, elevated intracranial pressure, and intracranial calcifications. The condition is unlike other diseases characterized by networks of small veins, including cerebral proliferative angiopathy, Sturge-Weber syndrome, or developmental venous anomaly. While this case may be the result of an anatomic variation leading to the congenital absence of or early occlusion of the deep venous system, the insidious nature over many years argues against this. The absence of large cortical veins suggests a congenital abnormality of the venous structure. The child's presentation with a seizure-like event followed by protracted hemiparesis is consistent with venous ischemia. We propose that this is likely to represent a new clinicopathological entity.

Quantitative Apparent Diffusion Coefficient Mapping May Predict Seizure Onset in Children With Sturge-Weber Syndrome

BACKGROUND

Sturge-Weber syndrome (SWS) is often accompanied by seizures, stroke-like episodes, hemiparesis, and visual field deficits. This study aimed to identify early pathophysiologic changes that exist before the development of clinical symptoms and to evaluate if the apparent diffusion coefficient (ADC) map is a candidate early biomarker of seizure risk in patients with SWS.

METHODS

This is a prospective cross-sectional study using quantitative ADC analysis to predict onset of epilepsy. Inclusion criteria were presence of the port wine birthmark, brain MRI with abnormal leptomeningeal capillary malformation (LCM) and enlarged deep medullary veins, and absence of seizures or other neurological symptoms. We used our recently developed normative, age-specific ADC atlases to quantitatively identify ADC abnormalities, and correlated presymptomatic ADC abnormalities with risks for seizures.

RESULTS

We identified eight patients (three girls) with SWS, age range of 40 days to nine months. One patient had predominantly LCM, deep venous anomaly, and normal ADC values. This patient did not develop seizures. The remaining seven patients had large regions of abnormal ADC values, and all developed seizures; one of seven patients had late onset seizures.

CONCLUSIONS

Larger regions of decreased ADC values in the affected hemisphere, quantitatively identified by comparison with age-matched normative ADC atlases, are common in young children with SWS and were associated with later onset of seizures in this small study. Our findings suggest that quantitative ADC maps may identify patients at high risk of seizures in SWS, but larger prospective studies are needed to determine sensitivity and specificity.

Cognitive and motor outcomes in children with unilateral Sturge-Weber syndrome: Effect of age at seizure onset and side of brain involvement

PURPOSE

Most children with Sturge-Weber syndrome (SWS) develop seizures that may contribute to neurocognitive status. In this study, we tested the hypothesis that very early seizure onset has a particularly detrimental effect on the cognitive and/or motor outcomes of children with unilateral SWS. We also tested whether side of SWS brain involvement modulates the effect of seizure variables on the pattern of cognitive abnormalities.

METHODS

Thirty-four children (22 girls; mean age 6.1years) with unilateral SWS and history of epilepsy in a longitudinal cohort underwent neurological and cognitive evaluations. Global intelligent quotient (GIQ), verbal intelligent quotient (VIQ), nonverbal intelligent quotient (IQ), and motor function were correlated with epilepsy variables, side and extent of brain involvement on magnetic resonance imaging (MRI).

RESULTS

Mean age at seizure onset was 1.3years (0.1-6years) and mean IQ at follow-up was 86 (45-118). Age at seizure onset showed a logarithmic association with IQ, with maximum impact of seizures starting before age 1year, both in uni- and multivariate regression analyses. In the left SWS group (N=20), age at seizure onset was a strong predictor of nonverbal IQ (p=0.001); while early seizure onset in the right-hemispheric group had a more global effect on cognitive functions (p=0.02). High seizure frequency and long epilepsy duration also contributed to poor outcome IQ independently in multivariate correlations. Children with motor involvement started to have seizures at/before 7months of age, while frontal lobe involvement was the strongest predictor of motor deficit in a multivariate analysis (p=0.017).

CONCLUSION

These findings suggest that seizure onset prior to age 1year has a profound effect on severity of cognitive and motor dysfunction in children with SWS; however, the effect of seizures on the type of cognitive deficit is influenced by laterality of brain involvement.

[Vascular anomalies. Part II: vascular malformations]

Vascular malformations are congenital vascular anomalies with normal endothelial turnover, which can affect the whole vessel tree (arterial, capillary or lymphatic) both as isolated defects or as part of a syndrome. Developmental errors during embryogenesis, such as abnormal signaling processes that control the apoptosis, maturation and growth of vascular cells, lead to the persistence of vascular plexus cells with some degree of differentiation. Vascular malformations are usually present at birth, although symptoms or complications may be manifested later. Since the overwhelming majority are symptomatic, treatment is indicated which is often aimed only at improving the symptoms by controlling the size.

GNAQ Mutation in the Venous Vascular Malformation and Underlying Brain Tissue in Sturge-Weber Syndrome

The recent identification of the somatic GNAQ mutation (c.548G > A) provides insight into the pathogenesis of Sturge–Weber syndrome (SWS). Although the primary SWS brain pathology is the leptomeningeal angiomatosis (LMA), cerebral cortical and white matter abnormalities play a prominent role in the disease manifestations. In some cases, SWS brain involvement is present even without detectable LMA on magnetic resonance imaging (MRI). To expand our understanding of the etiology of SWS brain pathology, surgical SWS brain specimens from nine children (age: 0.8–7.5 years) were carefully separated into LMA and (non-LMA) brain tissue; the latter did not contain any vascular malformation. A custom Competitive Allele-Specific TaqMan PCR (castPCR) assay to detect the mutation in GNAQ was performed in these separated specimens. The mutation was present in all nine LMA and seven of the nine non-LMA brain tissues. LMA tissues were significantly enriched by the mutation, as compared with non-LMA brain (mean: 7.2 ± 2.1% and 1.2 ± 0.4%, respectively; p = 0.008). These results demonstrate that the somatic GNAQ mutation in SWS is not confined to the venous vascular malformation but can directly (although less severely) affect underlying brain parenchyma, not directly affected by LMA, and possibly contribute to SWS brain pathology. Future studies should identify the specific cell type(s) affected by the mutation in the SWS-affected brain parenchyma.

Clinical and metabolic correlates of cerebral calcifications in Sturge-Weber syndrome

AIM

To evaluate clinical and metabolic correlates of cerebral calcifications in children with Sturge-Weber syndrome (SWS).

METHOD

Fifteen children (11 females, four males; age range 7mo-9y, mean 4y 1mo) with unilateral SWS underwent baseline and follow-up magnetic resonance imaging (MRI) with susceptibility weighted imaging (SWI), glucose metabolism positron emission tomography (PET), and neurocognitive assessment (mean follow-up 1y 8mo). Calcified brain volumes measured on SWI were correlated with areas of abnormal glucose metabolism, seizure variables, and cognitive function (IQ).

RESULTS

Ten children had brain calcification at baseline and 11 at follow-up. Mean calcified brain volume increased from 1.69 to 2.47cm³ (p=0.003) in these children; the rate of interval calcified volume increase was associated with early onset of epilepsy (Spearman's rho [r_s ]=-0.63, p=0.036). Calcified brain regions showed a variable degree of glucose hypometabolism with the metabolic abnormalities often extending to non-calcified cerebral lobes. Larger calcified brain volumes at baseline were associated with longer duration of epilepsy (r_s =0.69, p=0.004) and lower outcome IQ (r_s =-0.53, p=0.042).

INTERPRETATION

Brain calcifications are common and progress faster in children with SWS with early epilepsy onset, and are associated with a variable degree of hypometabolism, which is typically more extensive than the calcified area. Higher calcified brain volumes may indicate a risk for poorer neurocognitive outcome.

Update on classification and diagnosis of vascular malformations

PURPOSE OF REVIEW

This review provides an update of the classification in the classification of vascular anomalies since April 2014 at the International Society for the Study of Vascular Anomalies meeting in Melbourne, Australia.

RECENT FINDINGS

The reader will become familiar with how to diagnose the major vascular malformations, including capillary, venous, arteriovenous, and lymphatic and combinations thereof. In addition, vascular malformation syndromes, including those with overgrowth, will be clarified.

SUMMARY

Vascular malformations are common. Capillary malformations are now better understood through an updated classification. Verrucous hemangioma is truly a venulocapillary malformation that extends into the subcutis. PIK3Ca-Related Overgrowth Syndromes encompass Klippel-Trenaunay, Congenital Lipomatous Asymmetric Overgrowth of the Trunk with Lymphatic, Capillary, Venous, and Combined-Type Vascular Malformations, Epidermal Nevi, Scoliosis/Skeletal and Spinal Anomalies, Megalencephaly-Capillary Malformation-Polymicrogyria Syndrome (M-CAP), fibroadipose hyperplasia, and macrodactyly. Yet another syndrome should be highlighted: Capillary Malformation of the Lower Lip, Lymphatic Malformation of the Face and Neck, Asymmetry and Partial/Generalized Overgrowth. Knowledge of the genetic basis of vascular malformations will lead to future treatments.

Somatic GNAQ Mutation is Enriched in Brain Endothelial Cells in Sturge-Weber Syndrome

BACKGROUND

Sturge-Weber syndrome (SWS) is a rare congenital neurocutaneous disorder characterized by facial and extracraniofacial capillary malformations and capillary-venule malformations in the leptomeninges. A somatic mosaic mutation in GNAQ (c.548G>A; p.R183Q) was found in SWS brain and skin capillary malformations. Our laboratory showed endothelial cells in skin capillary malformations are enriched for the GNAQ mutation. The purpose of this study is to determine whether the GNAQ mutation is also enriched in endothelial cells in affected SWS brain.

METHODS

Two human SWS brain specimens were fractionated by fluorescence-activated cell sorting into hematopoietic (CD45), endothelial (CD31, VE-Cadherin, and vascular endothelial growth factor receptor 2), and perivascular (platelet-derived growth factor receptor beta) cells and cells negative for all markers. The sorted cell populations were analyzed for GNAQ p.R183Q mutation by droplet digital polymerase chain reaction. SWS patient-derived brain endothelial cells were selected by anti-CD31-coated magnetic beads and cultured in endothelial growth medium in vitro.

RESULTS

The GNAQ p.R183Q mutation was present in brain endothelial cells in two SWS specimens, with mutant allelic frequencies of 34.7% and 24.0%. Cells negative for all markers also harbored the GNAQ mutation. The mutant allelic frequencies in these unidentified cells were 9.2% and 8.4%. SWS patient-derived brain endothelial cells with mutant allelic frequencies of 14.7% and 21% survived and proliferated in vitro.

CONCLUSIONS

Our study provides evidence that GNAQ p.R183Q mutation is enriched in endothelial cells in SWS brain lesions and thereby reveals endothelial cells as a source of aberrant Gαq signaling. This will help to understand the pathophysiology of SWS, to discover biomarkers for predicting cerebral involvement, and to develop therapeutic targets to prevent neurological impairments in SWS.

Imaging of Glutamate Concentration in Sturge-Weber Syndrome

Investigators from Wayne State University studied a cohort of children with Sturge-Weber syndrome (SWS) and epilepsy using both glucose-based positron emission tomography (FDG-PET) to evaluate metabolic activity and proton magnetic resonance spectroscopic imaging (MRSI) to evaluate glutamate turnover.

Predictive Factors for Epilepsy in Pediatric Patients With Sturge-Weber Syndrome

BACKGROUND

Sturge-Weber syndrome is characterized by a facial port-wine stain associated with either or both a retinal angioma and a cerebral pial angioma. Because a pial angioma may not be evident on the initial imaging studies, individuals at risk for epilepsy are often not identified before their first seizure. The aim of this study is to identify predictive factors predisposing Sturge-Weber patients to epilepsy.

METHODS

The medical archives and photography database of our institution were reviewed to identify Sturge-Weber Syndrome patients followed up between 1990 and 2015. Patients without epilepsy were compared with patients with epilepsy based on the location of the port-wine stain, its extent and cerebral imaging.

RESULTS

Twenty-four patients were included in the study. Thirteen did not develop epilepsy. Patients with bilateral port-wine stain were at higher risk of epilepsy (P = 0.03). Unilateral port-wine stain did not increase the risk of epilepsy (P = 0.29) regardless of its extent. The presence of developmental venous anomalies on brain imaging was also associated with a higher risk of epilepsy (P = 0.03).

CONCLUSIONS

Bilateral facial port-wine stain and cerebral developmental venous anomalies increase the risk of epilepsy in Sturge-Weber syndrome patients. Because they can be detected at birth, they might guide preventive management and follow-up.

Predicting and Preventing Epilepsy in Sturge-Weber Syndrome?

Investigators from the University of Montreal studied potential predictors of epilepsy in young patients with Sturge-Weber syndrome (SWS).

Imaging increased glutamate in children with Sturge-Weber syndrome: Association with epilepsy severity

BACKGROUND

Sturge-Weber syndrome (SWS) is strongly associated with epilepsy. Brain tissue studies have suggested that epileptic activity in SWS is driven by glutamatergic synaptic activity. Here, we used proton magnetic resonance spectroscopic imaging (MRSI) to test if glutamate (GLU) concentrations are increased in the affected hemisphere and if such increases are associated with severity of epilepsy in children with SWS. We also studied the metabolic correlates of MRSI abnormalities, using glucose positron emission tomography (PET) imaging.

METHODS

3T MRI and glucose PET were performed in 10 children (age: 7-78 months) with unilateral SWS and a history of epilepsy. MRSI data were acquired from the affected (ipsilateral) and non-affected (contralateral) hemispheres. GLU, N-acetyl-aspartate (NAA) and creatine (Cr) were quantified in multiple voxels; GLU/Cr and NAA/Cr ratios were calculated and compared to seizure frequency as well as glucose PET findings.

RESULTS

The highest GLU/Cr ratios were found in the affected hemisphere in all children except one with severe atrophy. The maximum ipsilateral/contralateral GLU/Cr ratios ranged between 1.0 and 2.5 (mean: 1.6). Mean ipsilateral/contralateral GLU/Cr ratios were highest in the youngest children and showed a strong positive correlation with clinical seizure frequency scores assessed at the time of the scan (r=0.88, p=0.001) and also at follow-up (up to 1 year, r=0.80, p=0.009). GLU increases in the affected hemisphere coincided with areas showing current or previous increases of glucose metabolism on PET in 5 children. NAA/Cr ratios showed no association with clinical seizure frequency.

CONCLUSIONS

Increased glutamate concentrations in the affected hemisphere, measured by MRSI, are common in young children with unilateral SWS and are associated with frequent seizures. The findings lend support to the role of excess glutamate in SWS-associated epilepsy.