Right watershed cerebral infarction following neck cannulation for veno-arterial extracorporeal membrane oxygenation in pediatric septic shock: a case series.

Children supported by extracorporeal membrane oxygenation present a high risk of neurological complications. Although carotid cannulation is known to be associated with neurologic injury, conflicting data exist with regard to the predominance of right- or left-sided lesions. We describe here two infants requiring veno-arterial extracorporeal membrane oxygenation for septic shock who encountered right watershed infarction ipsilateral to carotid artery cannulation. Hemodynamic failure seems to be the most probable underlying mechanism. The asymmetry of transcranial Doppler metrics in one case and the low right regional cerebral oxygen saturation value observed soon after right cannulation in both cases suggest an insufficient cerebral collateral flow compensation. The risk of ipsilateral watershed injury should be considered before cervical cannulation, notably in the context of sepsis and an evaluation of the cerebral collateral blood flow before and just after cannulation may be interesting in order to identify infants with higher risk of ipsilateral ischemic lesions.

The Prognostic Value of Early Amplitude-Integrated Electroencephalography Monitoring After Pediatric Cardiac Arrest.

OBJECTIVES: To assess the ability of amplitude-integrated electroencephalography monitoring within 24 hours of the return of spontaneous circulation to prognosticate neurologic outcomes in children following cardiac arrest DESIGN:: Retrospective review of prospectively recorded data. An amplitude-integrated electroencephalography background score was calculated according to background activity during the first 24 hours after return of spontaneous circulation, a higher score correlating with more impaired background activity. The primary endpoint was the neurologic outcome as defined by the Pediatric Cerebral Performance Category at PICU discharge (Pediatric Cerebral Performance Category 1-3: a good neurologic outcome; Pediatric Cerebral Performance Category 4-6: a poor neurologic outcome). SETTING: A referral PICU. PATIENTS: Thirty children with a median age of 10 months (2-38 mo) and a male/female sex ratio of 1.3 were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighteen patients were assigned to the favorable outcome group and 12 to the unfavorable outcome group. The median time between return of spontaneous circulation and amplitude-integrated electroencephalography initiation was 4 hours (3-9 hr). The amplitude-integrated electroencephalography score within 24 hours after return of spontaneous circulation was significantly higher in the children with poor outcomes compared with those with good outcomes (12 ± 4 vs 25 ± 8; p < 0.001). Background activity during amplitude-integrated electroencephalography monitoring was able to predict poor neurologic outcomes at PICU discharge, with an area under the receiver operating characteristic curve of 0.91 (95% CI, 0.81-1.00). CONCLUSIONS: Early amplitude-integrated electroencephalography monitoring may help predict poor neurologic outcomes in children within 24 hours following cardiac arrest.

Early-onset stroke with moyamoya-like syndrome and extraneurological signs: a first reported paediatric series.

BACKGROUND: Moyamoya syndrome is characterised by an occlusion of the carotid terminations with the development of collateral vessels. Our objective is to describe a series of infants presenting early-onset moyamoya-like syndrome, which may constitute a distinct entity. METHODS: From a cohort of children with rare cerebral vascular pathologies, we studied eight infants (28 days-1 year) with early-onset moyamoya-like syndrome demonstrated by angiography. We retrospectively analysed the patterns on MRI and MRA, as well as all other available data. RESULTS: Median age at diagnosis was 7 months (IQR: 6-8) with arterial ischaemic stroke in the middle cerebral artery territory. All of the children experienced severe stroke recurrence within a median time of 11 months (IQR: 10-12), and all showed extraneurological symptoms. The anterior cerebral circulation was involved in all cases and the posterior circulation was involved in six. Two children died and all of the other children suffered permanent neurological deficits. CONCLUSIONS: The presence of extraneurological signs in cases of early-onset moyamoya syndrome is suggestive of a newly described systemic vasculopathy with predominantly cerebrovascular expression. Given its rapid progression marked by severe recurrent strokes and poor clinical outcome, early diagnosis could help in the decision to institute aggressive therapy.

Can we improve accuracy and reliability of MRI interpretation in children with optic pathway glioma? Proposal for a reproducible imaging classification.

INTRODUCTION: Magnetic resonance (MR) images from children with optic pathway glioma (OPG) are complex. We initiated this study to evaluate the accuracy of MR imaging (MRI) interpretation and to propose a simple and reproducible imaging classification for MRI. METHODS: We randomly selected 140 MRIs from among 510 MRIs performed on 104 children diagnosed with OPG in France from 1990 to 2004. These images were reviewed independently by three radiologists (F.T., 15 years of experience in neuroradiology; D.L., 25 years of experience in pediatric radiology; and J.L., 3 years of experience in radiology) using a classification derived from the Dodge and modified Dodge classifications. Intra- and interobserver reliabilities were assessed using the Bland-Altman method and the kappa coefficient. These reviews allowed the definition of reliable criteria for MRI interpretation. RESULTS: The reviews showed intraobserver variability and large discrepancies among the three radiologists (kappa coefficient varying from 0.11 to 1). These variabilities were too large for the interpretation to be considered reproducible over time or among observers. A consensual analysis, taking into account all observed variabilities, allowed the development of a definitive interpretation protocol. Using this revised protocol, we observed consistent intra- and interobserver results (kappa coefficient varying from 0.56 to 1). The mean interobserver difference for the solid portion of the tumor with contrast enhancement was 0.8 cm(3) (limits of agreement = -16 to 17). CONCLUSION: We propose simple and precise rules for improving the accuracy and reliability of MRI interpretation for children with OPG. Further studies will be necessary to investigate the possible prognostic value of this approach.

Extracranial vertebral artery dissection in children: natural history and management.

INTRODUCTION: The objective of this study is to describe clinical and imaging presentation and outcome in extracranial vertebral artery dissection. METHODS: Single-centre retrospective study over a 14-year period included 20 consecutive patients under the age of 16 years with extracranial vertebral artery dissection. The diagnosis was based on vascular imaging performed at the acute phase and clinical symptoms. RESULTS: A male predominance was observed (sex ratio 9/1). The first symptoms consisted of headache (45%), neck pain (15%), nausea (30%) and vertigo (30%). Clinical signs leading to admission to hospital were hemiparesis (60%), visual disorders with oculomotor disorders (20%) or visual field defects (20%) and cerebellar syndrome (35%). Eight patients (40%) reported repeated transient episodes of neurological deficits, prior to the diagnosis. The segment most commonly affected was V2-V3 (50%), followed by V3 (15%) and V2 (15%), V3-V4 (10%) and proximal V4 (10%). All patients but one presented cerebral infarction. Eleven patients received first-line treatment with low molecular weight heparin (LMWH), and nine patients received aspirin. Three patients experienced a recurrence of symptoms, one under vitamin K antagonist (VKA) and 2 under aspirin. All three were switched to LMWH with success. Fifty-eight percent of the dissected arteries were occluded at long-term follow-up, although 73% of them were patent at the acute phase. CONCLUSION: Initial imaging must include posterior fossa vessels and the craniocervical region with V2-V3 segments. Conventional angiography may be indicated in the absence of a definitive diagnosis on noninvasive imaging. Healing of the dissected vertebral artery predominantly resulted in occlusion, which does not constitute a pejorative factor but indicates good quality healing.

PWI-MRI and contrast extravasation in brain AVM help to estimate angiogenic activity.

INTRODUCTION: The aim of this study is to investigate perfusion characteristics of brain arteriovenous malformation (AVM) by means of MRI perfusion-weighted imaging (PWI). METHODS: Forty-three patients with brain AVM were prospectively included and investigated by PWI-MRI. Diagnosis of type of disease was made by angiogram. According to angiographic features, the study group was classified in three groups: two groups of patients with classical AVM (group 1 with few or no angiogenic feature (13 patients) and group 2 with many angiogenic features (18 patients)) and one group (group 3) which included patients with cerebral proliferative angiopathy (CPA; 12 patients). Twenty-one patients had never been treated endovascularly for their AVM and 22 patients received partial treatment by endovascular embolisation. Through PWI, corrected cerebral blood volume (CBVc), mean transit time (MTT), and percentage of microvascular leakage (MVL) as an indirect measure of permeability were assessed. RESULTS: The three patient groups did not differ significantly in baseline and clinical parameters. CBVc, MTT, and MVL differed significantly between the three groups (p = 0.003, p = 0.04, p = 0.01, respectively), with the lowest mean values found in group 1 and the highest in group 3. Mean MVL was 11.4 in group 1, 18.6 in group 2, and 21.9 in group 3. CONCLUSION: MRI can demonstrate differences in PWI parameters among patients with classical AVM and CPA, which are related to angiographic features of these AVMs. Through PWI, the level of angiogenic activity in AVMs may be monitored.

Inflammatory optic neuropathy in granulomatosis with polyangiitis can mimick isolated idiopathic optic neuritis.

OBJECTIVE: We describe a clinico-radiological presentation of inflammatory optic neuropathy that mimicked optic neuritis. METHODS: Retrospective single-center case series and literature review of optic neuropathy without orbital pseudotumor. RESULTS: Five local patients fulfilled the inclusion criteria. Clinical presentation revealed rapidly progressive severe unilateral visual loss, retrobulbar pain (n = 4), and paralytic strabismus (simultaneous = 2, protracted = 2) without proptosis. Optic nerve abnormality was not appreciated on initial scan review. Patients did not have any general activity of the granulomatosis with polyangiitis. Upon follow-up magnetic resonance imaging and initial imaging review, all patients revealed orbital apex anomalies. Visual acuity improved in three patients who received high-dose intravenous glucocorticosteroids immediately. Relapse was frequent and visual outcome was poor (final vision > 20/40 in two patients only). Literature review identified 16 well-documented cases of granulomatosis with polyangiitis-related isolated optic neuropathies. Magnetic resonance imaging revealed no abnormality (n = 6), optic nerve and/or sheath involvement (n = 9), apex infiltration (n = 3), and/or pachymeningitis (n = 7). CONCLUSION: Granulomatosis with polyangiitis is a rare yet potentially blinding cause of inflammatory optic neuropathy. Optic neuropathy in granulomatosis with polyangiitis may occur in the absence of systemic symptoms of disease activity and is challenging to distinguish from other inflammatory and non-inflammatory disorders affecting visual acuity. Several clinical and imaging clues suggest that optic neuropathy results from the development of an extravascular granulomatous process within the optic nerve sheath in the orbital apex, a place that is difficult to image. In a granulomatosis with polyangiitis patient with unexplained visual loss and a seemingly normal workup (fundoscopy, biology, and imaging), clinician should keep a high index of suspicion.

Anti-CEA Pretargeted Immuno-PET Shows Higher Sensitivity Than DOPA PET/CT in Detecting Relapsing Metastatic Medullary Thyroid Carcinoma: Post Hoc Analysis of the iPET-MTC Study.

Pretargeting parameters for the use of anti-carcinoembryonic antigen (CEA) bispecific monoclonal antibody TF2 and the 68Ga-labeled IMP288 peptide for immuno-PET have been optimized in a first-in-humans study performed on medullary thyroid carcinoma (MTC) patients (the iPET-MTC study). The aim of this post hoc analysis was to determine the sensitivity of immuno-PET in relapsing MTC patients, in comparison with conventional imaging and 18F-l-dihydroxyphenylalanine (18F-DOPA) PET/CT. Methods: Twenty-five studies were analyzed in 22 patients. All patients underwent immuno-PET 1 and 2 h after 68Ga-IMP288 injection pretargeted by TF2, in addition to neck, thoracic, abdominal, and pelvic CT; bone and liver MRI; and 18F-DOPA PET/CT. The gold standard was histology or confirmation by one other imaging method or by imaging follow-up. Results: In total, 190 lesions were confirmed by the gold standard: 89 in lymph nodes, 14 in lungs, 46 in liver, 37 in bone, and 4 in other sites (subcutaneous tissue, heart, brain, and pancreas). The number of abnormal foci detected by immuno-PET was 210. Among these, 174 (83%) were confirmed as true-positive by the gold standard. Immuno-PET showed a higher overall sensitivity (92%) than 18F-DOPA PET/CT (65%). Regarding metastatic sites, immuno-PET had a higher sensitivity than CT, 18F-DOPA PET/CT, or MRI for lymph nodes (98% vs. 83% for CT and 70% for 18F-DOPA PET/CT), liver (98% vs. 87% for CT, 65% for 18F-DOPA PET/CT, and 89% for MRI), and bone (92% vs. 64% for 18F-DOPA PET/CT and 86% for MRI), whereas sensitivity was lower for lung metastases (29% vs. 100% for CT and 14% for 18F-DOPA PET/CT). Tumor SUVmax at 60 min ranged from 1.2 to 59.0, with intra- and interpatient variability. Conclusion: This post hoc study demonstrates that anti-carcinoembryonic antigen immuno-PET is an effective procedure for detecting metastatic MTC lesions. Immuno-PET showed a higher overall sensitivity than 18F-DOPA PET/CT for disclosing metastases, except for the lung, where CT remains the most effective examination.

Usefulness of FDG-PET/CT-Based Radiomics for the Characterization and Genetic Orientation of Pheochromocytomas Before Surgery.

PURPOSE: To assess the potential added value of FDG-PET/CT radiomics for the characterization of pheochromocytomas (PHEO) and their genetic orientation prior to surgery and genetic testing. METHODS: This retrospective monocentric study, included 49 patients (52 tumors) that underwent both FDG-PET/CT and MIBG scan before surgery. A germline mutation was secondarily identified in 13 patients in one of the genes related to Cluster 1 (n = 4) or Cluster 2 (n = 9). No mutation was identified in 32 patients and 4 did not have genetic testing. Correlation between several PET-based biomarkers, including SUVmax, metabolic tumor volume (MTV), total lesion glycolysis (TLG) and textural features, and biochemical and genetic features were analyzed. RESULTS: Sensitivity of FDG-PET/CT alone was 92%, and 98% when combined to MIBG. The SUVmax was significantly higher for mutated tumors classified in Cluster 1 than in Cluster 2 (p = 0.002) or for tumors with no identified mutations (p = 0.04). MTV and TLG of the tumors with the most intense uptake discriminated mutated Cluster 2 from sporadic tumors, but not from Cluster 1 tumors. Textural features combined with MTV led to better differentiation between sporadic and mutated tumors (p < 0.05). CONCLUSION: FDG-PET/CT is useful for preoperative characterization of PHEO, and when combined with radiomics biomarkers, provides evidences for a genetic predisposition.

Repair process in spontaneous intradural dissecting aneurysms in children: report of eight patients and review of the literature.

OBJECTIVE: The objective of this study is to present a series of eight pediatric patients (less than 16 years old) with complete spontaneous thrombosis of spontaneous intradural dissecting aneurysms. MATERIAL AND METHODS: Since 1989, eight consecutive patients in whom the cerebral aneurysms (four in middle cerebral arteries, one in posterior cerebral artery, three in basilar arteries) were found complete spontaneous thrombosis on follow-up MRI/MRA or conventional angiography. Patient histories and angiographic features were retrospectively reviewed. RESULTS: Complete thrombosis of aneurysms in between first few days to 7 months was found in eight out of 1,587 patients (0.5%) in this recent series. Aneurysm repair was related to multivariate processes. Headache (50%), vomiting, and hemiplegia (37.5%) were common presenting symptoms. Partial or total resolution of the symptoms in a few months was often seen. Associated parent artery occlusions (50%) were also observed. CONCLUSION: Spontaneous resolution of intradural dissecting aneurysm with or without parent artery occlusion is not uncommon even in the pediatric population. Aneurysm repair is a dynamic and multifaceted entity. Mural hematoma appears to be the most important factor promoting thrombosis and healing of the dissecting intracranial aneurysms.

Spinal arteriovenous malformation associated with syringomyelia.

The authors describe 4 cases of syringomyelia-associated spinal cord arteriovenous malformation (AVM). All cases were managed with embolization of the AVM. Treatments were aimed to stabilize the AVM itself and not directed toward the syrinx. In 3 of the 4 cases the syringomyelia resolved after treatment. Reports concerning AVM as a cause of syringomyelia is very scarce and lacks posttreatment clinical information. In light of the clinical course and imaging findings, the authors propose a theory that venous hypertension in the spinal cord is the trigger for the development of syringomyelia, which may reverse after AVM treatment.

Long-term visual acuity in patients with optic pathway glioma treated during childhood with up-front BB-SFOP chemotherapy-Analysis of a French pediatric historical cohort.

BACKGROUND: Visual outcome is one of the main issues in the treatment of optic pathway glioma in childhood. Although the prognostic factors of low vision have been discussed extensively, no reliable indicators for visual loss exist. Therefore, we aimed to define initial and evolving factors associated with long-term vision loss. METHODS: We conducted a multicenter historical cohort study of children treated in France with up-front BB-SFOP chemotherapy between 1990 and 2004. Visual acuity performed at the long-term follow-up visit or within 6 months prior was analyzed. Logistic regression analysis was used to estimate the effects of clinical and radiological factors on long-term visual outcome. FINDINGS: Of the 180 patients in the cohort, long-term visual acuity data were available for 132 (73.3%) patients (median follow-up: 14.2 years; range: 6.1-25.6). At the last follow-up, 61/132 patients (46.2%) had impaired vision, and 35 of these patients (57.3%) were partially sighted or blind. Multivariate analysis showed that factors associated with a worse prognosis for long-term visual acuity were an age at diagnosis of < 1 year (OR 3.5 [95% CI: 1.1-11.2], p = 0.04), tumor extent (OR 4.7 [95% CI: 1.2-19.9], p = 0.03), intracranial hypertension requiring one or more surgical procedures (OR 5.6 [95% CI: 1.8-18.4], p = 0.003), and the need for additional treatment after initial BB-SFOP chemotherapy (OR 3.5 [95% CI: 1.1-11.9], p = 0.04). NF1 status did not appear as a prognostic factor, but in non-NF1 patients, a decrease in tumor volume with contrast enhancement after BB-SFOP chemotherapy was directly associated with a better visual prognosis (OR 0.8 [95% CI: 0.8-0.9], p = 0.04). INTERPRETATION: Our study confirms that a large proportion of children with optic pathway glioma have poor long-term outcomes of visual acuity. These data suggest new prognostic factors for visual acuity, but these results need to be confirmed further by large- and international-scale studies.

Pathomechanisms of symptomatic developmental venous anomalies.

BACKGROUND AND PURPOSE: Although it is generally accepted that developmental venous anomalies (DVAs) are benign vascular malformations, over the past years, we have seen patients with symptomatic DVAs. Therefore, we performed a retrospective study and a literature study to review how, when, and why DVAs can become clinically significant. METHODS: Charts and angiographic films of 17 patients with DVAs whose 18 vascular symptoms could be attributed to a DVA were selected from a neurovascular databank of our hospital. MRI had to be available to rule out any other associated disease. In the literature, 51 cases of well-documented symptomatic DVAs were found. Pathomechanisms were divided into mechanical and flow-related causes. RESULTS: Mechanical (obstructive or compressive) pathomechanisms accounted for 14 of 69 symptomatic patients resulting in hydrocephalus or nerve compression syndromes. Flow-related pathomechanisms (49 of 69 patients) could be subdivided into complications resulting from an increase of flow into the DVA (owing to an arteriovenous shunt using the DVA as the drainage route; n=19) or a decrease of outflow (n=26) or a remote shunt with increased venous pressure (n=4) leading to symptoms of venous congestion. In 6 cases, no specific pathomechanisms were detected. CONCLUSIONS: Although DVAs should be considered benign, under rare circumstances, they can be symptomatic. DVAs, as extreme variations of normal venous drainage, may represent a more fragile venous drainage system that can be more easily affected by in- and outflow alterations. The integrity of the DVA needs to be preserved irrespective of the treatment that should be tailored to the specific pathomechanism.

Dural arteriovenous shunts: a new classification of craniospinal epidural venous anatomical bases and clinical correlations.

BACKGROUND AND PURPOSE: The craniospinal epidural spaces can be categorized into 3 different compartments related to their specific drainage role of the bone and central nervous system, the ventral epidural, dorsal epidural, and lateral epidural groups. We propose this new classification system for dural arteriovenous shunts and compare demographic, angiographic, and clinical characteristics of dural arteriovenous shunts that develop in these 3 different locations. METHODS: Three hundred consecutive cases (159 females, 141 males; mean age: 47 years; range, 0 to 87 years) were reviewed for patient demographics, clinical presentation, multiplicity, presence of cortical and spinal venous reflux, and outflow restrictions and classified into the 3 mentioned groups. RESULTS: The ventral epidural group (n=150) showed a female predominance, more benign clinical presentations, lower rate of cortical and spinal venous reflux, and no cortical and spinal venous reflux without restriction of the venous outflow. The dorsal epidural group (n=67) had a lower mean age and a higher rate of multiplicity. The lateral epidural group (n=63) presented later in life with a male predominance, more aggressive clinical presentations, and cortical and spinal venous reflux without evidence of venous outflow restriction. All differences were statistically significant (P<0.001). CONCLUSIONS: Dural arteriovenous shunts predictably drain either in pial veins or craniofugally depending on the compartment involved by the dural arteriovenous shunt. Associated conditions (outflow restrictions, high-flow shunts) may change that draining pattern. The significant differences between the groups of the new classification support the hypothesis of biological and/or developmental differences in each epidural region and suggest that dural arteriovenous shunts are a heterogeneous group of diseases.

Arterial vascularization of the cranial nerves.

We discuss the arterial supply of the cranial nerves from their exit out of the brain stem to their exit from the skull base. Four distinct groups can be differentiated from an embryologic and phylogenetic standpoint. Understanding the arterial supply to the cranial nerves and the potential anastomoses is paramount in the endovascular treatment of dural AV shunts and highly vascularized tumors of the skull base to avoid neurologic deficits.

MRI Interscanner Agreement of the Association between the Susceptibility Vessel Sign and Histologic Composition of Thrombi.

BACKGROUND AND PURPOSE: The susceptibility vessel sign (SVS) on magnetic resonance imaging (MRI) is related to thrombus location, composition, and size in acute stroke. No previous study has determined its inter-MRI scanner variability. We aimed to compare the diagnostic accuracy in-vitro of four different MRI scanners for the characterization of histologic thrombus composition. METHODS: Thirty-five manufactured thrombi analogs of different composition that were histologically categorized as fibrin-dominant, mixed, or red blood cell (RBC)-dominant were scanned on four different MRI units with T2* sequence. Nine radiologists, blinded to thrombus composition and MRI scanner model, classified twice, in a 2-week interval, the SVS of each thrombus as absent, questionable, or present. We calculated the weighted kappa with 95% confidence interval (CI), sensitivity, specificity and accuracy of the SVS on each MRI scanner to detect RBC-dominant thrombi. RESULTS: The SVS was present in 42%, absent in 33%, and questionable in 25% of thrombi. The interscanner agreement was moderate to good, ranging from .45 (CI: .37-.52) to .67 (CI: .61-.74). The correlation between the SVS and the thrombus composition was moderate (κ: .50 [CI: .44-.55]) to good κ: .76 ([CI: .72-.80]). Sensitivity, specificity, and accuracy to identify RBC-dominant clots were significantly different between MRI scanners (P < .001). CONCLUSION: The diagnostic accuracy of SVS to determine thrombus composition varies significantly among MRI scanners. Normalization of T2*sequences between scanners may be needed to better predict thrombus composition in multicenter studies.

Intracerebral Gene Therapy Using AAVrh.10-hARSA Recombinant Vector to Treat Patients with Early-Onset Forms of Metachromatic Leukodystrophy: Preclinical Feasibility and Safety Assessments in Nonhuman Primates.

No treatment is available for early-onset forms of metachromatic leukodystrophy (MLD), a lysosomal storage disease caused by autosomal recessive defect in arylsulfatase A (ARSA) gene causing severe demyelination in central and peripheral nervous systems. We have developed a gene therapy approach, based on intracerebral administration of AAVrh.10-hARSA vector, coding for human ARSA enzyme. We have previously demonstrated potency of this approach in MLD mice lacking ARSA expression. We describe herein the preclinical efficacy, safety, and biodistribution profile of intracerebral administration of AAVrh.10-hARSA to nonhuman primates (NHPs). NHPs received either the dose planned for patients adjusted to the brain volume ratio between child and NHP (1×dose, 1.1×10(11) vg/hemisphere, unilateral or bilateral injection) or 5-fold this dose (5×dose, 5.5×10(11) vg/hemisphere, bilateral injection). NHPs were subjected to clinical, biological, and brain imaging observations and were euthanized 7 or 90 days after injection. There was no toxicity based on clinical and biological parameters, nor treatment-related histological findings in peripheral organs. A neuroinflammatory process correlating with brain MRI T2 hypersignals was observed in the brain 90 days after administration of the 5×dose, but was absent or minimal after administration of the 1×dose. Antibody response to AAVrh.10 and hARSA was detected, without correlation with brain lesions. After injection of the 1×dose, AAVrh.10-hARSA vector was detected in a large part of the injected hemisphere, while ARSA activity exceeded the normal endogenous activity level by 14-31%. Consistently with other reports, vector genome was detected in off-target organs such as liver, spleen, lymph nodes, or blood, but not in gonads. Importantly, AAVrh.10-hARSA vector was no longer detectable in urine at day 7. Our data demonstrate requisite safe and effective profile for intracerebral AAVrh.10-hARSA delivery in NHPs, supporting its clinical use in children affected with MLD.

Vascular malformations of the brain.

Pediatric neurovascular malformations are rare. However, proper diagnosis and management are mandatory to achieve a good neurocognitive outcome. Among them several types can be identified with specificities for each. In the newborn and infancy, the most frequent cerebral venous malformation is vein of Galen aneurysmal malformation. It can be discovered antenatally, in neonates (mainly in cases with hemodynamic impact), or in infants presenting with macrocrania and hydrocephalus. Treatment of choice is endovascular, by transarterial selective occlusion of pathological vessels. Interventions are staged with a first session at around 5 months, adjusted to neurological development. Late consequences, especially if left untreated or treated outside the therapeutic window, are delayed neurocognitive development and seizures. Pial arteriovenous malformation can also be diagnosed antenatally. Regional parenchymal destruction could occur in the first months of life, requiring early endovascular treatment. Dural sinus malformations are the third main type of neurovascular malformation, and are also diagnosed antenatally or in the first months of life. Cardiac tolerance is usually good. Adverse consequences are mainly neurocognitive delay due to chronic venous hyperpressure or acute hemorrhage due to thrombosis of the pathological sinuses. Nidal-type brain arteriovenous malformation and cavernous angioma are usually seen later in children, with hemorrhage often being the first presenting symptom.