Neurological involvement in secondary hemophagocytic lymphohistiocytosis in children.

OBJECTIVES: To describe neurological characteristics and CNS involvement on MRI in secondary hemophagocytic lymphohistiocytosis (sHLH) and differentiate it from primary hemophagocytic lymphohistiocytosis (pHLH) and acute disseminated encephalomyelitis (ADEM). METHODS: Nine children with sHLH who had neurological symptoms were retrospectively included. Characteristics of brain MRI were compared to those of 15 children with pHLH and neurological involvement and 44 children with ADEM. RESULTS: Three children (33%) presented with isolated neurological symptoms. Neurological signs occurred within one month following Epstein-Barr virus primary infection or systemic juvenile arthritis exacerbation in 8 patients (89%). Eight children (89%) had MRI lesions. sHLH MRI lesions were distinct of those of pHLH by morphology and signal with more frequent hyposignal intensities on T1-weighted sequences (p = 0.01) and well-defined and less fuzzy lesions (p = 0.03). All patients survived and one patient presented severe motor and cognitive disability. CONCLUSION: Neurological symptoms of sHLH are non-specific and their outcome is favorable in most of the children. MRI at onset may help to differentiate this condition from pHLH.

Intracerebral Gene Therapy in Four Children with Sanfilippo B Syndrome: 5.5-Year Follow-Up Results.

We report the safety (primary endpoint) and efficacy (secondary endpoint) of a novel intracerebral gene therapy at 5.5 years of follow-up in children with Sanfilippo B. An uncontrolled, phase 1/2 clinical trial was performed in four patients aged 20, 26, 30, and 53 months. Treatment consisted of 16 intracerebral and cerebellar deposits of a recombinant adeno-associated viral vector encoding human α-N-acetylglucosaminidase (rAAV2/5-hNAGLU) plus immunosuppression. An intermediate report at 30 months was previously published. Thirty treatment-emergent adverse events were reported between 30 and 66 months after surgery, including three classified as severe with no serious drug reactions. At 5.5 years, NAGLU activity was persistently detected in the lumbar cerebrospinal fluid (18% of unaffected control level). Circulating T cells reacting against NAGLU peptides were present, indicating a lack of acquired tolerance. Patients 2, 3, and 4 showed progressive brain atrophy and neurocognitive evolution that did not differ from untreated Sanfilippo A/B children. Patient 1, enrolled at 20 months of age, had a milder disease with normal brain imaging and a significantly better cognitive outcome than the three other patients and untreated patients, although not equivalent to normal children. After 5.5 years, the primary endpoint of this study was achieved with a good safety profile of the proposed treatment. We have also observed sustained enzyme production in the brain and absence of immunological tolerance. Cognitive benefit was not confirmed in the three oldest patients. Milder disease in the youngest patient supports further investigations of adeno-associated vector-mediated intracerebral gene therapy in Sanfilippo B.

Progressive Leukodystrophy-Like Demyelinating Syndromes with MOG-Antibodies in Children: A Rare Under-Recognized Phenotype.

Acquired demyelinating syndromes (ADS) are frequently associated with myelin oligodendrocytes glycoprotein (MOG) antibodies in children. Clinical phenotypes are heterogeneous and may delay the diagnosis, especially when they relapse and are atypical, mimicking diseases such as multiple sclerosis or neuromyelitis optica spectrum disorders . Here, we describe two children: one with a progressive cognitive and behavioral deterioration with seizures after only one relapse and the other with similar clinical impairments associated with multiple relapses. Brain magnetic resonance imaging revealed a subsequent progressive leukodystrophy-like lesion with diffuse bilateral white matter injuries in both patients. Cerebrospinal fluid analysis showed pleiocytosis, increased level of proteins with no oligoclonal bands. Metabolic and inflammatory blood markers were all negative. Brain biopsy was performed in the second child and nonspecific inflammatory lesions with no argument for histiocytosis or tumor were observed. Clinical and radiological stabilization were obtained after active immunotherapy. Retrospective analysis of anti-MOG antibodies in these two children was positive at the earlier stage of the disease and turned negative after treatment and during follow-up. Leukodystrophy-like ADS with anti-MOG-antibodies may display distinct progressive phenotype and have a severe neurological prognosis. Early diagnosis and appropriate treatment may improve outcome in these children.

Imaging in Pediatric Multiple Sclerosis : An Iconographic Review.

Pediatric-onset multiple sclerosis (POMS) is defined by a first multiple sclerosis (MS) attack occurring before 18 years old and is diagnosed by demonstration of dissemination in time (DIT) and space (DIS). Although guidelines evolved over the years, they always recognized the importance of magnetic resonance imaging (MRI) for diagnosis. The 2017 McDonald criteria are increasingly used and have been validated in several cohorts. The use of MRI is the most important tool for the early diagnosis, monitoring, and assessment of treatment response of MS and standard protocols include precontrast and postcontrast T1, T2, fluid attenuation inversion recovery (FLAIR) and diffusion sequences. A distinctive MS lesion compromises white matter and it is well-demarcated and confluent, showing demyelination, inflammation, gliosis, and relative axonal preservation. Considering the growing recognition of pediatric MS as a differential diagnosis for children presenting with a clinical central nervous system event, we present a POMS lesions guide (periventricular, juxtacortical, infratentorial, spinal cord, cortical, tumefactive, black hole, contrast-enhanced). Owing to its rareness, POMS is a diagnosis by exclusion and MRI plays a fundamental role in distinguishing POMS from other demyelinating and non-demyelinating conditions. Three main groups of disorders can mimic POMS: inflammatory, metabolic and tumoral; however, imaging patterns earlier described lower the possibilities of alternative diagnoses and strongly suggest POMS when likely.

Intracerebral gene therapy in children with mucopolysaccharidosis type IIIB syndrome: an uncontrolled phase 1/2 clinical trial.

BACKGROUND: Mucopolysaccharidosis type IIIB syndrome (also known as Sanfilippo type B syndrome) is a lysosomal storage disease resulting in progressive deterioration of cognitive acquisition after age 2-4 years. No treatment is available for the neurological manifestations of the disease. We sought to assess the safety and efficacy of a novel intracerebral gene therapy. METHODS: Local regulatory authorities in France allowed inclusion of up to four children in this phase 1/2 study. Treatment was 16 intraparenchymal deposits (four in the cerebellum) of a recombinant adenoassociated viral vector serotype 2/5 (rAAV2/5) encoding human α-N-acetylglucosaminidase (NAGLU) plus immunosuppressive therapy. We assessed tolerance, neurocognitive progression, brain growth, NAGLU enzymatic activity in CSF, and specific anti-NAGLU immune response for 30 months after surgery. This trial is registered with EudraCT, number 2012-000856-33, and the International Standard Clinical Trial Registry, number ISRCTN19853672. FINDINGS: Of seven eligible children, the four youngest, from France (n=2), Italy (n=1), and Greece (n=1), aged 20, 26, 30, and 53 months, were included between February, 2012, and February, 2014. 125 adverse events were recorded, of which 117 were treatment emergent and included six classified as severe, but no suspected unexpected serious adverse drug reactions were seen. Vector genomes were detected in blood for 2 days after surgery. Compared with the natural history of mucopolysaccharidosis type III syndromes, neurocognitive progression was improved in all patients, with the youngest patient having function close to that in healthy children. Decrease in developmental quotient was -11·0 points in patient one, -23·0 in patient two, -29·0 in patient three, and -17·0 in patient four, compared with -37·7 in the natural history of the disease. NAGLU activity was detected in lumbar CSF and was 15-20% of that in unaffected children. Circulating T lymphocytes that proliferated and produced tumour necrosis factor α upon ex-vivo exposure to NAGLU antigens were detectable at 1-12 months and 3-12 months, respectively, but not at 30 months in three of four patients. INTERPRETATION: Intracerebral rAVV2/5 was well tolerated and induced sustained enzyme production in the brain. The initial specific anti-NAGLU immune response that later subsided suggested acquired immunological tolerance. The best results being obtained in the youngest patient implies a potential window of opportunity. Longer follow-up is needed to further assess safety outcomes and persistence of improved cognitive development. FUNDING: Association Française Contre les Myopathies, Vaincre les Maladies Lysosomales, Institut Pasteur, and UniQure.

Regional Pediatric Acute Stroke Protocol: Initial Experience During 3 Years and 13 Recanalization Treatments in Children.

BACKGROUND AND PURPOSE: To evaluate hyperacute management of pediatric arterial ischemic stroke, setting up dedicated management pathways is the first recommended step to prove the feasibility and safety of such treatments. A regional pediatric stroke alert protocol including 2 centers in the Paris-Ile-de-France area, France, was established. METHODS: Consecutive pediatric patients (28 days-18 years) with confirmed arterial ischemic stroke who had acute recanalization treatment (intravenous r-tPA [recombinant tissue-type plasminogen activator], endovascular procedure, or both) according to the regional pediatric stroke alert were retrospectively reviewed during a 40-month period. RESULTS: Thirteen children, aged 3.7 to 16.6 years, had recanalization treatment. Median time from onset to magnetic resonance imaging was 165 minutes (150-300); 9 out of 13 had large-vessel occlusion. Intravenous r-tPA was used in 11 out of 13 patients, with median time from onset to treatment of 240 minutes (178-270). Endovascular procedure was performed in patients time-out for intravenous r-tPA (n=2) or after intravenous r-tPA inefficiency (n=2). No intracranial or peripheral bleeding was reported. One patient died of malignant stroke; outcome was favorable in 11 out of 12 survivors (modified Rankin Scale score 0-2). CONCLUSIONS: Hyperacute recanalization treatment in pediatric stroke, relying on common protocols and adult/pediatric ward collaboration, is feasible. Larger systematic case collection is encouraged.

Intracerebral administration of adeno-associated viral vector serotype rh.10 carrying human SGSH and SUMF1 cDNAs in children with mucopolysaccharidosis type IIIA disease: results of a phase I/II trial.

Mucopolysaccharidosis type IIIA is a severe degenerative disease caused by an autosomal recessive defect of a gene encoding a lysosomal heparan-N-sulfamidase, the N-sulfoglycosamine sulfohydrolase (SGSH), the catalytic site of which is activated by a sulfatase-modifying factor (SUMF1). Four children (Patients 1-3, aged between 5.5 and 6 years; Patient 4 aged 2 years 8 months) received intracerebral injections of an adeno-associated viral vector serotype rh.10-SGSH-IRES-SUMF1 vector in a phase I/II clinical trial. All children were able to walk, but their cognitive abilities were abnormal and had declined (Patients 1-3). Patients 1-3 presented with brain atrophy. The therapeutic vector was delivered in a frameless stereotaxic device, at a dose of 7.2×10(11) viral genomes/patient simultaneously via 12 needles as deposits of 60 µl over a period of 2 hr. The vector was delivered bilaterally to the white matter anterior, medial, and posterior to the basal ganglia. Immunosuppressive treatment (mycophenolate mofetil and tacrolimus) was initiated 15 days before surgery and maintained for 8 weeks (mycophenolate mofetil) or throughout follow-up (tacrolimus, with progressive dose reduction) to prevent elimination of transduced cells. Safety data collected from inclusion, during the neurosurgery period and over the year of follow-up, showed good tolerance, absence of adverse events related to the injected product, no increase in the number of infectious events, and no biological sign of toxicity related to immunosuppressive drugs. Efficacy analysis was necessarily preliminary in this phase I/II trial on four children, in the absence of validated surrogate markers. Brain atrophy evaluated by magnetic resonance imaging seemed to be stable in Patients 1 and 3 but tended to increase in Patients 2 and 4. Neuropsychological evaluations suggested a possible although moderate improvement in behavior, attention, and sleep in Patients 1-3. The youngest patient was the most likely to display neurocognitive benefit.

Stroke due to lyme neuroborreliosis: changes in vessel wall contrast enhancement.

BACKGROUND AND PURPOSE: Neuroborreliosis is a rare cause of stroke in children. We aim here to demonstrate the diagnostic value of gadolinium-enhanced magnetic resonance imaging (MRI) for demonstrating vessel wall abnormality in a child with brainstem stroke. RESULTS: We report here the case of an 8-year-old boy with cerebral vasculitis and stroke due to Lyme neuroborreliosis. Imaging studies revealed the presence of ischemic lesions in the pons and cerebellum, with focal stenosis of the basilar artery on magnetic resonance angiography and focal gadolinium enhancement of the basilar artery wall. Nine months after treatment, clinical outcome was favorable, with no enhancement of the basilar artery. CONCLUSIONS: Gadolinium-enhanced MRI provided additional information facilitating the diagnosis of vasculitis in a child with Lyme neuroborreliosis and stroke. The location of vessel wall enhancement was correlated with the topography of the acute infarct, and the lack of vessel lumen obstruction supported the diagnosis of vasculitis rather than any other cause.

Obstetrical and neonatal characteristics vary with birthweight in a cohort of 100 term newborns with symptomatic arterial ischemic stroke.

OBJECTIVES: Many questions remain regarding the mechanism of perinatal stroke. METHODS: In a series of 100 prospectively enrolled term neonates with symptomatic arterial ischemic stroke, we explored family antecedents, pregnancy and delivery conditions and clinical presenting features and distinguished features of the 50 larger infants with the remainder. Cardiac and cervical arterial imaging were performed in 70 and 51 cases. RESULTS: Previous fetal loss, first pregnancy, primiparity, twin-gestation, cesarean and traumatic delivery, neonatal distress, male sex and premature rupture of membranes were statistically more common than in the general population. Normal pregnancy proportion and mean birthweight were in the normal range, arguing against a vasculo-placental origin in the majority. Furthermore, there was an excess of large babies. The larger infants were more subject to suffer from acute perinatal events, with a trend for an excess of neonatal distress (p=0.065) and for more severe presenting features (p=0.027), while the lighter were more likely to have experienced longstanding obstetrical risk factors such as complicated pregnancy (p=0.047) and tobacco exposure (p=0.028). Cervical MR angiography showed an internal carotid occlusion in two babies, whereas echo-Doppler was always normal; in one case the two methods were discordant. Echocardiography was non-informative. INTERPRETATION: The data from this prospective cohort of neonates with stroke confirm that many obstetrical and perinatal factors are risk determinants. They also suggest that birthweight and gender may be biomarkers of two populations of neonates with different pathological mechanisms. MR angiography appears more sensitive than echo-Doppler for the exploration of the neonatal cervical vasculature.

Expanding spectrum of encephalitis with NMDA receptor antibodies in young children.

The authors report here 2 cases of subacute-onset encephalitis with N-methyl-D-aspartate (NMDA) receptor antibodies. One had a paraneoplastic syndrome associated with a neuroblastoma, whereas the other had no primary tumor. This disease was originally described as a paraneoplastic syndrome in young women with ovarian teratoma. The clinical features of both children resembled the typical symptoms reported for older patients with this disease: psychomotor deterioration, movement disorders, and seizures. One of the reported cases is the first known case of paraneoplastic encephalitis with NMDA antibodies in a child with neuroblastoma. Both cases described here were younger than any of the previously reported cases. Consistent with recently published series, this report suggests that the spectrum of symptoms of encephalitis with NMDA receptor antibodies is probably wider than previously thought.

Prolonged refractory status epilepticus with early and persistent restricted hippocampal signal MRI abnormality.

We report a series of four children with a prolonged refractory status epilepticus with an early persistent and restricted hippocampal signal MRI abnormality but otherwise no proven etiology. The mean duration of status epilepticus was 53 days (range, 20-91 days) with a mean length of stay in Pediatric Intensive Care Unit (PICU) of 2 months (range, 26-115 days). Neurological outcome showed epilepsy disease in all, and mild to severe disability. In long-term follow-up, the initial MRI signal abnormality developed into a cortical atrophy in all cases. The establishment of the diagnosis, etiology, and options for treatment are discussed.

Acute transverse myelitis in children: clinical course and prognostic factors.

The objective of this study was to describe the clinical course of acute transverse myelitis in children, to identify prognostic factors, and to compare our findings with published data Twenty-four children, aged 2 to 14 years and admitted with a diagnosis of acute transverse myelitis, were studied. Clinical features and results of investigations were collected at admission and during the course of the disease. Motor, sphincter, and global outcomes were compared with those in the main adult and pediatric series. During the initial phase, the most common presenting symptoms were pain (88%) and fever (58%). Motor loss preceded sphincter dysfunction in two thirds of patients and became bilateral in half of the patients. When maximal deficit was achieved (plateau), the patients presented a combination of sensory, motor, and sphincter dysfunctions without radicular involvement The motor loss consistently involved the lower limbs but was inconsistent and moderate in the upper limbs. The mean duration of the plateau was 1 week. The recovery phase was characterized by a progressive improvement of all deficits. Sphincter dysfunction improved more slowly than did the other deficits. A full recovery was achieved by 31% of the patients; minimal sequelae were present in 25% and mild to severe sequelae in 44%. An unfavorable outcome was associated with complete paraplegia (P = .03) and/or a time to maximal deficit shorter than 24 hours (P = .005). A favorable outcome was associated with a plateau shorter than 8 days (P = .03), the presence of supraspinal symptoms (P = .01), and a time to independent walking shorter than 1 month (P = .01). The course of acute transverse myelitis in children proceeds through three stages, an initial phase, a plateau, and a recovery phase, each characterized by specific clinical features. The global outcome was favorable in 56% of patients. Several prognostic factors were identified.

Sturge-Weber disease with repercussion on the prenatal development of the cerebral hemisphere.

Sturge-Weber syndrome was diagnosed in a neonate on basis of a characteristic port-wine stain. In the absence of any acute neurologic episode, MR images obtained when the infant was aged 3 months showed a typical pial vascular dysplasia, as well as prominent hypotrophy of the homolateral hemisphere. Areas suggesting the presence of developmental dysplasia of the cerebral mantel were found in association with the typical pial vascular anomaly. The prenatal effect of Sturge-Weber disease on normal brain development may best be explored by using a better evaluation with cerebral imaging shortly after birth.