Clinical correlates of white matter blood flow perfusion changes in Sturge-Weber syndrome: a dynamic MR perfusion-weighted imaging study

Retrospective Analysis of Presymptomatic Treatment In Sturge-Weber Syndrome

Background

Ninety percent of infants with Sturge-Weber syndrome (SWS) brain involvement have seizure onset before 2 years of age; this is associated with worse neurologic outcome. Presymptomatic treatment before seizure onset may delay seizure onset and improve outcome, as has been shown in other conditions with a high-risk of developing epilepsy such as tuberous sclerosis complex. Electroencephalogram (EEG) may be a biomarker to predict seizure onset. This retrospective clinical data analysis aims to assess impact of presymptomatic treatment in SWS.

Methods

This two-centered, IRB-approved, retrospective study analyzed records from patients with SWS brain involvement. Clinical data recorded included demographics, age of seizure onset (if present), brain involvement extent (unilateral versus bilateral), port-wine birthmark (PWB) extent, family history of seizure, presymptomatic treatment if received, neuroscore, and anti-seizure medication. EEG reports prior to seizure onset were analyzed.

Results

Ninety-two patients were included (48 females), and 32 received presymptomatic treatment outside of a formal protocol (5 aspirin, 16 aspirin and levetiracetam; 9 aspirin and oxcarbazepine, 2 valproic acid). Presymptomatically-treated patients were more likely to be seizure-free at 2 years (15 of 32; 47% versus 7 of 60; 12%; p<.001). A greater percentage of presymptomatically-treated patients had bilateral brain involvement (38% treated versus 17% untreated; p=.026). Median hemiparesis neuroscore at 2 years was better in presymptomatically-treated patients. In EEG reports prior to seizure onset, the presence of slowing, epileptiform discharges, or EEG-identified seizures was associated with seizure onset by 2 (p=.001).

Conclusion

Presymptomatic treatment is a promising approach to children diagnosed with SWS prior to seizure onset. Further study is needed, including prospective drug trials, long-term neuropsychological outcome, and prospective EEG analysis to assess this approach and determine biomarkers for presymptomatic treatment.

Arterial spin-labeled (ASL) perfusion in children with Sturge-Weber syndrome: a retrospective cross-sectional study

PURPOSE

Sturge-Weber syndrome (SWS) is a developmental disorder with venous hypertension and associated tissue responses including pial angiomatosis, cortical calcifications, and cerebral atrophy. Arterial spin-labeled (ASL) perfusion is an advanced MR sequence which can assess perfusion, without the need for contrast. We systematically evaluated the potential benefits of using ASL in Sturge-Weber syndrome, to determine the extent of intracranial perfusion abnormality and stage of disease, relevant for prognostication and surgical planning.

METHODS

Two pediatric neuroradiologists retrospectively evaluated ASL perfusion imaging of 31 children with confirmed SWS and recorded the presence of hyper-perfusion, hypo-perfusion, or normal perfusion. The presence and distribution of ASL abnormality were compared against the presence and side of atrophy/calcification and pial angiomatosis on standard MR sequences.

RESULTS

Thirty-one children (52% female, median age 16.7 months) with SWS had ASL imaging. Seven (23%) had hyper-perfusion, 15 (48%) had hypo-perfusion, and 9 (29%) had no perfusion abnormalities. ASL perfusion abnormality matched the location of SWS findings on conventional imaging in 86% (19/22). ASL demonstrated statistically significant increased perfusion in the early stage of the disease and decreased perfusion when there was atrophy. The parietal lobe was involved in 86% of cases.

CONCLUSION

ASL perfusion imaging is an advanced technique which may contribute to earlier diagnosis and more accurate prognostication of Sturge-Weber syndrome, helping guide management and potential surgical planning.

Arterial Spin-Labeling Perfusion Imaging in the Early Stage of Sturge-Weber Syndrome

BACKGROUND AND PURPOSE

Sturge-Weber syndrome is a rare congenital neuro-oculo-cutaneous disorder. Although the principal mechanism of Sturge-Weber syndrome is characterized by a leptomeningeal vascular malformation, few data regarding perfusion abnormalities of the brain parenchyma are available. Therefore, the aim of this study was to assess the diagnostic performance of arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome before 1 year of age until 3.5 years of age. We hypothesized that a leptomeningeal vascular malformation has very early hypoperfusion compared with controls with healthy brains.

MATERIALS AND METHODS

We compared the CBF using arterial spin-labeling perfusion imaging performed at 3T MR imaging in the brain parenchymal regions juxtaposing the leptomeningeal vascular malformation in patients with Sturge-Weber syndrome (n = 16; 3.5 years of age or younger) with the corresponding areas in age-matched controls with healthy brains (n = 58). The analysis was performed following two complementary methods: a whole-brain voxel-based analysis and a visual ROI analysis focused on brain territory of the leptomeningeal vascular malformation.

RESULTS

Whole-brain voxel-based comparison revealed a significant unilateral decrease in CBF localized in the affected cortices of patients with Sturge-Weber syndrome (P < .001). CBF values within the ROIs in patients with Sturge-Weber syndrome were lower than those in controls (in the whole cohort: median, 25 mL/100g/min, versus 44 mL/100g/min; P < .001). This finding was also observed in the group younger than 1 year of age, emphasizing the high sensitivity of arterial spin-labeling in this age window in which the diagnosis is difficult.

CONCLUSIONS

Arterial spin-labeling perfusion imaging in the early stage of Sturge-Weber syndrome can help to diagnose the disease by depicting a cortical hypoperfusion juxtaposing the leptomeningeal vascular malformation.

Isolated leptomeningeal angiomatosis in the sixth decade of life, an adulthood variant of Sturge Weber Syndrome (Type III): role of advanced Magnetic Resonance Imaging and Digital Subtraction Angiography in diagnosis

Background

Sturge-Weber syndrome (SWS) is primarily diagnosed in pediatric population, but clinical presentation in late adulthood is rarely reported. Evolution of radiological findings in the adulthood variant of SWS with isolated leptomeningeal angiomatosis has never been reported to our knowledge.

Case presentation

We report here a case of an isolated temporo-parieto-occipital leptomeningeal angiomatosis on the right cerebral hemisphere in a sixty-two-year-old male who presented with generalized seizure, GCS score 14/15 (E4 V4 M6) with equal and reacting pupils, psychomotor slowing, left hemineglect and grade 4 power in the left upper and lower limbs. Over a period of 48 h his neurological status deteriorated, but recovered spontaneously over a week on titration with anticonvulsants. He had a prior history of treatment for focal leptomeningitis, three years ago. Cerebrospinal fluid (CSF) analysis showed glucose of 75 mg/dL, proteins of 65 mg/dL and culture grew no organisms. On follow-up, he had intermittent episodes of focal seizure for two years. Initial, computed tomography of brain showed hyperdense lesion in the parieto-occipital convexity subarachnoid space on the right cerebral hemisphere mimicking subarachnoid hemorrhage and computed tomography angiography showed no significant abnormality. Magnetic resonance imaging (MRI) of brain showed intense pial enhancement in the right temporo-parieto-occipital region with a subtle T2W hyperintense signal in the underlying subcortical white matter without edema or infarct or mass effect. Digital subtraction cerebral angiography (DSA) showed hypertrophy of the cerebral arteries, arteriolo-capillary bed and venules in the right temporo-parieto-occipital territory associated with early arterio-capillary and venous opacification. Serial MRI done after six months, one and two years showed increase in the T2W hyperintense signal in the subcortical white matter and cortical atrophy with no changes in the pial enhancement. MR perfusion imaging showed reduced cerebral blood flow (CBF) and cerebral blood volume (CBV) in the right parieto-temporo-occipital cortical and subcortical regions and increased perfusion in the leptomeninges with reduction of the NAA / Cr ratios in spectroscopy.

Conclusion

Conglomeration of various radiological findings in MRI, Perfusion, MRS and DSA with the clinical presentation can aid in establishing the diagnosis of this rare presentation of SWS-type 3 variant in late adulthood.

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.

Utility of the transcranial doppler in the evaluation and follow-up of children with Sturge-Weber Syndrome

INTRODUCTION

Sturge-Weber syndrome (SWS) is a neurocutaneous syndrome with typical clinical features including seizures, chronic hemiplegia, hemianopsia and intellectual impairment. Progressive clinical decline may be attributable, at least in part, to progressive venous ischemia. Transcranial Doppler (TCD) ultrasonography could be useful to monitor the degree of hemodynamic involvement and its progression.

PURPOSE

To determine whether there is an association between the degree of asymmetry in TCD and intensity of clinical and radiological involvement and whether there is a correlation between clinical changes and changes in serial TCD.

METHODS

In fourteen SWS pediatric patients and two "possible cases" (infants younger than two years old without previously known brain involvement, but with other typical signs of SWS) mean flow velocity in the middle cerebral arteries (MCA) was measured by TCD in both hemispheres. The percent difference between hemispheres (asymmetry) was calculated. Clinical and radiological severity was scored using scales. The correlation between TCD asymmetry and SWS clinical and radiological scores was analyzed at baseline, as well as the correlation between the changes in the different variables (TCD asymmetry, clinical and radiological cores) during evolution and in relation to the changes due to therapy.

RESULTS

The percentage of MCA velocity asymmetry was positively correlated with the clinical severity score (p = 0.04), and with seizure frequency (p = 0.014). Throughout evolution, therapeutic and clinical changes were associated with noticeable changes in transcranial doppler asymmetry in some cases.

CONCLUSIONS

TCD may provide a noninvasive method to assess the severity of blood flow abnormalities at baseline and a method to monitor children for progressive changes over time.

The role of adenosine A1 receptor agonist in adenosine augmentation therapy for patients with refractory epilepsy in Sturge-Weber syndrome: An in vitro electrophysiological study

PURPOSES

This study was to further explore the adenosine dysfunction in refractory epilepsy in Sturge-Weber Syndrome (SWS), to evaluate the neuronal-level effect of the A1 receptor (A1R) agonist on both excitatory pyramidal neurons and inhibitory interneurons, to discuss the possibility of adenosine augmentation therapy (AAT) using A1R agonist for treating refractory epilepsy in SWS.

MATERIALS AND METHODS

The intrinsic excitatory properties of pyramidal cells (PCs) and fast-spiking (FS) interneurons from human brain tissues with SWS cases and malformations of cortical development (MCD) cases were compared using electrophysiology. With application of either A1R agonist or antagonist, the neuronal-level effect of A1R agonist was evaluated in vitro in PCs and FS interneurons from SWS cases and MCD cases.

RESULTS

No significant difference of passive excitatory properties of PCs and FS interneurons was found between SWS cases and MCD cases. In terms of the neuronal-level effect of A1R agonist, with 22.88 ± 1.12% percentage of decreased frequency, FS interneurons showed relatively highest sensitivity of A1R agonist application, compared with PCs from SWS cases and FS interneurons and PCs from MCD cases.

CONCLUSION

Our results supported the potential of AATs using A1R agonist to be a novel therapy for reducing life burden from patients with refractory epilepsy in SWS, with application to epileptic generation region but not propagation region.

Early magnetic resonance imaging to detect presymptomatic leptomeningeal angioma in children with suspected Sturge-Weber syndrome

AIM

We aimed to evaluate the contribution of early magnetic resonance imaging (MRI) for the presymptomatic diagnosis of Sturge-Weber syndrome (SWS) in infants with a facial port-wine birthmark (PWB).

METHOD

Asymptomatic infants with a facial PWB who performed a first MRI scan before 3 months and a second MRI scan after 9 months were included in this study. Leptomeningeal enhancement on T1-weighted imaging and four indirect signs of leptomeningeal angioma (choroid plexus enlargement, cerebral atrophy, signal inversion of the white matter with T2 hyposignal, and T1 hypersignal) were screened on the first MRI scan and correlated with clinical and/or radiological diagnosis of SWS.

RESULTS

Thirteen of 30 included patients had SWS with leptomeningeal angioma. Eleven had a leptomeningeal enhancement on the first MRI scan and 10 had associated indirect signs. The presence of a direct or at least one indirect sign of leptomeningeal angioma on the first MRI scan confirmed the diagnosis of SWS with a sensitivity of 100 per cent (95% confidence interval 75-100%) and a specificity of 94 per cent (71-100%).

INTERPRETATION

Early diagnosis of SWS is possible on contrast-enhanced MRI performed in asymptomatic infants with a facial PWB before the age of 3 months. This early detection would help to select patients who may benefit from early neuroprotective intervention.

WHAT THIS PAPER ADDS

Specific magnetic resonance imaging markers provide early diagnosis of leptomeningeal angioma in Sturge-Weber syndrome (SWS). Presymptomatic diagnosis of SWS should help to select patients for early therapy intervention.

Asymmetric cavernous sinus enlargement: a novel finding in Sturge-Weber syndrome

PURPOSE

Enlargement of deep cerebral veins and choroid plexus engorgement are frequently reported in Sturge-Weber syndrome. We aim to describe cavernous sinus involvement in patients with this syndrome and to identify possible clinical-neuroimaging correlations.

METHODS

Sixty patients with Sturge-Weber syndrome (31 females, mean age 4.5 years) and 120 age/sex-matched controls were included in this retrospective study. We performed a visual analysis to identify patients with asymmetric cavernous sinus enlargement. Then, we measured on axial T2WI the left (A), right (B), and bilateral (LL) transverse diameters of the cavernous sinus. We calculated the module of the difference |A-B| and the cavernous sinus asymmetry index as the ratio |A-B|/LL. Differences among groups were assessed by Mann-Whitney U and Kruskal-Wallis tests. Clinicoradiological associations were evaluated by Fisher exact test.

RESULTS

We found seven subjects (11.6%) with asymmetric CS enlargement. The |A-B| and cavernous sinus asymmetry index were higher in patients with asymmetric CS enlargement compared with controls and patients without visible CS abnormalities (p_B < 0.05). Asymmetric CS enlargement was always ipsilateral to facial port-wine stains (7/7), and, when present, to leptomeningeal vascular malformations (4/7). It was significantly associated with ipsilateral bone marrow changes (p = 0.013) and dilated veins (p = 0.002). Together with brain atrophy and deep venous dilatation, this sign was associated with neurological deficits (p < 0.05).

CONCLUSIONS

We expanded the spectrum of venous abnormalities in SWS, showing the presence of asymmetric cavernous sinus enlargement in more than one tenth of patients, likely related to increased venous drainage.

Reliability and Clinical Correlation of Transcranial Doppler Ultrasound in Sturge-Weber Syndrome

BACKGROUND

The reproducibility of transcranial Doppler (TCD) ultrasound measurements in Sturge-Weber syndrome (SWS) and TCD's ability to predict neurological progression is unknown.

METHODS

In 14 individuals with SWS, TCD measured mean flow velocity, pulsatility index, peak systolic velocity, and end-diastolic velocity in the middle, posterior, and anterior cerebral arteries of the affected and unaffected hemisphere. TCD was performed either once (n = 5) or twice in one day (n = 9). We assessed the reproducibility of the measurements performed twice on the same day on subjects and compared the TCD measurements to previously published age-matched controls. Clinically obtained neuroimaging was scored for extent and severity of SWS brain involvement. Patients were prospectively assigned SWS neuroscores.

RESULTS

Middle cerebral artery velocity (r = 0.79, P = 0.04, n = 7), posterior cerebral artery velocity (r = 0.90, P = 0.04, n = 5), and anterior cerebral artery pulsatility index (r = 0.82, P = 0.02, n = 7) were reproducible TCD measurements comparing same-day percent side-to-side differences. In subjects with SWS, affected and unaffected mean peak systolic velocity and end-diastolic velocity in the middle, posterior, and anterior cerebral arteries were globally lower compared with age-matched control subjects. Subjects with the lowest affected middle cerebral artery velocity had the greatest worsening in the total neurological score between time 1 and 2 (r = -0.73, P = 0.04, n = 8) and the most severe magnetic resonance imaging involvement of the affected frontal lobe (r = -0.82, P = 0.007, n = 9).

CONCLUSIONS

TCD may be a reliable measure with potential clinical value, indicating that blood flow may be globally decreased in SWS patients with unilateral brain involvement.

Epileptogenesis in neurocutaneous disorders with focus in Sturge Weber syndrome

Epilepsy is a major morbidity in Sturge Weber syndrome, a segmental vascular neurocutaneous disorder classically associated with facial angiomas, glaucoma, and leptomeningeal capillary-venous type vascular malformations. The extent of the latter correlates with neurological outcome. Post-zygotic mosaicism for the activating mutation p.R183Q of the GNAQ gene has been identified as the major cause.  GNAQ encodes for an alpha subunit of a heterotrimeric G protein critical to blood vessel development. The earlier the timing of the mutation in development, the more severe the involvement, e.g. from isolated port-wine stains to the full syndrome. The strongest predictors of adverse outcomes are MRI and the presence of angiomas involving any part of the forehead, delineated inferiorly from the outer canthus of the eye to the top of the ear, and including the upper eyelid.  The neurological course may be progressive and the typical constellation of symptoms is focal onset seizures, hemiparesis, headache, stroke-like episodes, behavior problems, intellectual disability, and visual field deficits. Antiseizure medications are effective in about half of patients. The presence of localized seizures, focal neurological deficits, and drug resistant epilepsy indicate epilepsy surgical evaluation. Earlier seizure onset, i.e. before six months of age, is associated with a more severe course with significant residual deficits. Factors contributing to epileptogenesis include decreased brain tissue perfusion due to abnormal venous drainage, anoxic injury contributing to cerebral calcification, breakdown of the blood-brain barrier, and the presence of developmental cortical malformations. Pre-symptomatic prophylactic treatment may be a future option to modify the course of the disease including the associated epileptogenesis.

Osseous intramedullary signal alteration and enhancement in Sturge-Weber syndrome: an early diagnostic clue

INTRODUCTION

Sturge-Weber syndrome (SWS) is a sporadic phakomatosis with variable intracranial involvement. Port-wine stain, choroidal angioma, and leptomeningeal angiomatosis typify the full disease spectrum. Disease manifestations generally evolve toward cerebral hemiatrophy and compensatory hemicalvarial enlargement. However, recognizable imaging correlates may be lacking early on. We have observed SWS-related marrow signal changes to be prevalent in patients of all ages. The purpose of this study is to evaluate bone marrow abnormalities in patients with Sturge-Weber syndrome.

METHODS

The MR imaging database at an academic children's hospital was queried for "Sturge-Weber" to build a cohort for retrospective analysis. Two board-certified neuroradiologists reviewed MR exams for abnormalities of the bone marrow, globes, susceptibility, and perfusion. A two-tailed Fisher's exact test was applied to evaluate the association between variables.

RESULTS

Twenty brain MR exams from 19 SWS patients, mean age 4.8 +/- 5.8 years (range 6 months-16 years), met the inclusion criteria. All patients with port-wine stains (18/20) had leptomeningeal enhancement, marrow T2 prolongation, and/or marrow enhancement ipsilaterally. Leptomeningeal enhancement was only present in 53%. Eighty percent had unilateral bone marrow abnormalities. In 37% (all <5 years), marrow abnormalities occurred without leptomeningeal angiomatosis. Thirty-five percent had facial bones involvement; 75% of these had ipsilateral choroidal angiomas.

CONCLUSION

Bone marrow signal abnormality and enhancement is common ipsilateral to the nevus flammeus in SWS. As this may be the sole brain MR abnormality in some patients, it may reflect mild phenotypes or an early disease manifestation, and could help stratify patients for early intervention.

Sturge-Weber Syndrome (Encephalotrigeminal Angiomatosis): Recent Advances and Future Challenges

Sturge-Weber syndrome (SWS) is a congenital, sporadically occurring, neurocutaneous syndrome that presents classically with port-wine stain, leptomeningeal angiomas, and glaucoma. The systemic implications of SWS are vast and involve not only ophthalmic manifestations but also dermatologic, neurologic, and oral manifestations. Neuroimaging, in particular, plays an important role in the diagnosis and management of this disease. Recent discoveries have been made regarding the genetic pathogenesis of SWS. In addition, recent advances have been made in the management of the 2 most common ophthalmic manifestations of SWS: diffuse choroidal hemangioma and glaucoma. Despite these new contributions to the field, many challenges still remain. The management of diffuse choroidal hemangioma is wide ranging and includes photodynamic therapy, brachytherapy, radiotherapy, and antivascular endothelial growth factor injections, but all have had limited or varied success. Although there have been recent advances in knowledge and technique, the management of glaucoma is extremely complex, given the high surgical risks for complications and a poor response rate to medical therapy. Further studies are critical to maximize our knowledge of this difficult disease.

New vascular classification of port-wine stains: improving prediction of Sturge-Weber risk

BACKGROUND

Facial port-wine stains (PWSs) are usually isolated findings; however, when associated with cerebral and ocular vascular malformations they form part of the classical triad of Sturge-Weber syndrome (SWS).

OBJECTIVES

To evaluate the associations between the phenotype of facial PWS and the diagnosis of SWS in a cohort with a high rate of SWS.

METHODS

Records were reviewed of all 192 children with a facial PWS seen in 2011-13. Adverse outcome measures were clinical (seizures, abnormal neurodevelopment, glaucoma) and radiological [abnormal magnetic resonance imaging (MRI)], modelled by multivariate logistic regression.

RESULTS

The best predictor of adverse outcomes was a PWS involving any part of the forehead, delineated at its inferior border by a line joining the outer canthus of the eye to the top of the ear, and including the upper eyelid. This involves all three divisions of the trigeminal nerve, but corresponds well to the embryonic vascular development of the face. Bilateral distribution was not an independently significant phenotypic feature. Abnormal MRI was a better predictor of all clinical adverse outcome measures than PWS distribution; however, for practical reasons guidelines based on clinical phenotype are proposed.

CONCLUSIONS

Facial PWS distribution appears to follow the embryonic vasculature of the face, rather than the trigeminal nerve. We propose that children with a PWS on any part of the 'forehead' should have an urgent ophthalmology review and a brain MRI. A prospective study has been established to test the validity of these guidelines.

Sturge-Weber syndrome: from the past to the present

Sturge-Weber syndrome is a rare sporadic neurocutaneous syndrome the hallmark of which is a facial port-wine stain involving the first division of the trigeminal nerve, ipsilateral leptomeningeal angiomata and angioma involving the ipsilateral eye. Our understanding of the disease process has vastly improved since it was first described in 1879, with recent identification of an activating somatic mutation in the GNAQ gene found in association with both Sturge-Weber syndrome and non-syndromic facial port-wine stain. Sturge-Weber syndrome is marked by a variable but usually progressive course in early childhood characterised by seizures, stroke-like episodes, headaches, neurological and cognitive deterioration, hemiparesis, glaucoma and visual field defects. More recently, the increased prevalance of otolaryngological, endocrine and emotional-behavioural issues have been established. Neurophysiology and neuroimaging studies provide information regarding the evolution of changes in Sturge-Weber syndrome over time. Early recognition and aggressive management of symptoms remains cornerstone in the management of this syndrome. An international collaborative effort is needed to maximise our understanding of the natural history and response to interventions in Sturge-Weber Syndrome.

Role of MRI in patient selection for surgical treatment of intractable epilepsy in infancy

Epilepsy surgery is an effective treatment in selected patients with localization-related intractable epilepsy. The success of epilepsy surgery is in part dependent upon identification of a lesion on MRI. In infants, the surgical epileptogenic substrates include focal cortical dysplasia (FCD), hemimegalencephaly, tuberous sclerosis complex, Sturge Weber syndrome, hypoxic-ischemic or cerebrovascular injury and low-grade tumor. The sensitivity of MRI in identifying the epileptogenic substrate is influenced by the nature of the epileptogenic substrate, MRI technique and expertise of the interpreting physician. The MRI features of some lesions such as FCD may differ in infants compared to children and adults; the white matter adjacent to FCD may demonstrate lower T2 and higher T1 signal in some infants due to premature myelination, while in others, the white matter demonstrates higher T2 or lower T1 signal due to demyelination, dysmyelination or gliosis, similar to children and adults. The appearances of some lesions, such as FCD, may change with time, due to brain maturation or seizure related changes. MRI for patients with localization-related intractable epilepsy should have high-resolution, multiplanar and multisequence. In infants, volumetric T1 and high-resolution T2 imaging are recommended. FLAIR and proton density sequences are less helpful in infants due to lack of myelin in the white matter. The physician interpreting the scan should be familiar with the imaging appearances of epileptogenic substrates and may need to review the scan more than once if a lesion is not seen on initial inspection.

Perfusion deficits in patients with mild traumatic brain injury characterized by dynamic susceptibility contrast MRI

Perfusion deficits in patients with mild traumatic brain injury (TBI) from a military population were characterized by dynamic susceptibility contrast perfusion imaging. Relative cerebral blood flow (rCBF) was calculated by a model-independent deconvolution approach from the tracer concentration curves following a bolus injection of gadolinium diethylenetriaminepentaacetate (Gd-DTPA) using both manually and automatically selected arterial input functions (AIFs). Linear regression analysis of the mean values of rCBF from selected regions of interest showed a very good agreement between the two approaches, with a regression coefficient of R = 0.88 and a slope of 0.88. The Bland-Altman plot also illustrated the good agreement between the two approaches, with a mean difference of 0.6 ± 12.4 mL/100 g/min. Voxelwise analysis of rCBF maps from both approaches demonstrated multiple clusters of decreased perfusion (p < 0.01) in the cerebellum, cuneus, cingulate and temporal gyrus in the group with mild TBI relative to the controls. MRI perfusion deficits in the cerebellum and anterior cingulate also correlated (p < 0.01) with neurocognitive results, including the mean reaction time in the Automated Neuropsychological Assessment Metrics and commission error and detection T-scores in the Continuous Performance Test, as well as neurobehavioral scores in the Post-traumatic Stress Disorder Checklist-Civilian Version. In conclusion, rCBF calculated using AIFs selected from an automated approach demonstrated a good agreement with the corresponding results using manually selected AIFs. Group analysis of patients with mild TBI from a military population demonstrated scattered perfusion deficits, which showed significant correlations with measures of verbal memory, speed of reaction time and self-report of stress symptoms.

A perfusion-metabolic mismatch in Sturge-Weber syndrome: a multimodality imaging study

OBJECTIVE

We combined perfusion weighted imaging (PWI) with 2-deoxy-2[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET) to study the relationship between regional metabolic and perfusion abnormalities and their clinical correlates in children with Sturge-Weber syndrome (SWS).

METHODS

Fifteen children (age: 0.9-10 years) with unilateral SWS underwent high-resolution PWI and FDG PET prospectively. Regional (lobar) asymmetry indices (AIs) of subcortical white matter (WM) cerebral blood flow (CBF) were correlated with corresponding cortical FDG uptake asymmetries, extent of leptomeningeal vascular malformation and clinical seizure variables.

RESULTS

Abnormal cortical glucose metabolism and/or subcortical WM CBF were seen in all lobes affected by vascular malformation and extended to lobes not affected by abnormal pial vessels in 6 patients. Lower CBF was associated with lower cortical glucose metabolism in the temporal, parietal and occipital lobes (p≤0.02). While decreased perfusion was associated with hypometabolism in most cases, increased regional CBF (found in 6 patients) was commonly associated with relatively mild or no hypometabolism. Ten of 24 cerebral lobes with normal glucose metabolism in the affected hemisphere showed abnormal perfusion. High seizure frequency was associated with severe parieto-occipital hypoperfusion (p≤0.03), while long duration of epilepsy was related to frontal lobe hypometabolism (p=0.015).

CONCLUSIONS

Regional perfusion and cortical metabolic abnormalities can extend beyond lobes affected by leptomeningeal vascular malformations and are related to epilepsy in SWS. Despite a general correlation between perfusion and metabolism, increased WM perfusion with preserved cortical metabolism in overlying cortex is a common pattern of a perfusion/metabolic mismatch. This may represent a disease stage where cortical function is preserved while increased WM perfusion provides collateral drainage of cortex via the deep vein system.

Updates and future horizons on the understanding, diagnosis, and treatment of Sturge-Weber syndrome brain involvement

AIM

To review recent developments in the understanding, diagnosis, and treatment of Sturge-Weber syndrome (SWS).

METHOD

Members of the Brain Vascular Malformation Consortium Sturge-Weber Syndrome National Workgroup contributed their expertise to review the literature and present promising directions for research.

RESULTS

The increasing number of reports dealing with SWS over the last decade reflects progress in the diagnosis and understanding of the neurological involvement. The proliferation of centers and advocacy groups to care for patients with SWS and to stimulate research has aided the development of new insights into the clinical manifestations and the pathophysiology of neurological progression, and the development of novel hypotheses to direct future research. Many key questions remain, but the tools and networks to answer them are being developed.

INTERPRETATION

This review summarizes important new knowledge and presents new research directions that are likely to provide further insights, earlier diagnosis, improved treatments, and possibly, prevention of this syndrome.

Comparison between acetazolamide challenge and 10% carbon dioxide challenge perfusion CT in rat C6 glioma

RATIONALE AND OBJECTIVES

The aim of this study was to investigate the effect of perfusion computed tomography (PCT) with acetazolamide (ACZ) challenge and compare it to 10% carbon dioxide (CO(2)) challenge in rat C6 glioma.

MATERIALS AND METHODS

PCT was performed on 32 rats, including 20 with orthotopically implanted C6 gliomas and 12 serving as controls. Ten rats with gliomas and six normal rats underwent PCT with ACZ challenge. The other 10 rats with gliomas and six normal rats underwent PCT with 10% CO(2) challenge. The raw data were processed using Philips computed tomographic brain perfusion software. Perfusion parameters before and after the challenge were recorded. Percentage changes due to ACZ administration and 10% CO(2) challenge were calculated. Pearson's correlation coefficients were used to investigate relationships between percentage changes in perfusion parameters and vascular endothelial growth factor and microvessel density.

RESULTS

In C6 gliomas, percentage change in cerebral blood flow was significantly different between ACZ (72.73%) and 10% CO(2) (28.47%) challenge (P < .01). Percentage change in cerebral blood volume was 37.85% with ACZ and 24.69% with 10% CO(2) challenge (P = .02). In controls, percentage change in cerebral blood flow was significantly different between ACZ (117.42%) and 10% CO(2) (65.86%) challenge (P < .01). For percentage change in cerebral blood volume, there was no significant difference between ACZ (107.51%) and 10% CO(2) (92.95%) challenge. Significant correlations were observed among percentage changes in vascular endothelial growth factor, microvessel density, and cerebral blood volume (P < .01). Percentage change in cerebral blood flow correlated well with vascular endothelial growth factor.

CONCLUSIONS

The results of this study indicate that PCT with ACZ challenge is a more reliable technique compared to 10% CO(2) challenge for the quantitative evaluation of microcirculation in gliomas.