Incidence rate and prevalence of pediatric-onset multiple sclerosis in Sweden: A population-based register study.

BACKGROUND AND PURPOSE: Pediatric-onset multiple sclerosis (PoMS) is associated with high health care use. To plan resource allocation for this patient group, knowledge of the incidence rate and prevalence is important. However, such studies are scarce, few are population-based, and the methodology varies widely. We aimed to address this knowledge gap by performing a nationwide study of the incidence rate and prevalence of PoMS in Sweden, an area of high multiple sclerosis (MS) incidence and prevalence. METHODS: MS cases were identified by linking two nationwide registers, the National Patient Register and the Swedish MS Registry. MS cases having their first central nervous system demyelinating event or MS clinical onset before age 18 years were classified as pediatric onset. Incidence rate and prevalence were estimated annually over the study period (2006-2016) for the total population and stratified by sex and age group (<12, 12-15, and 16-17 years). Temporal trends and ratios between sexes and age groups were estimated. RESULTS: We identified 238 incident cases from 2006 to 2016, corresponding to an overall crude incidence rate of 1.12 per 100,000 person-years and an overall crude prevalence of 2.82 per 100,000 population. There was a higher incidence rate among females and the highest age category. The overall incidence rate and prevalence estimates remained stable during the study period. CONCLUSIONS: Sweden exhibits a consistently high incidence rate and prevalence of PoMS that has remained stable over time. This knowledge serves as a tool to aid in planning resource allocation and health services for this patient population.

Clinical and neuroimaging phenotypes of autoimmune glial fibrillary acidic protein astrocytopathy: A systematic review and meta-analysis.

OBJECTIVE: This study was undertaken to provide a comprehensive review of neuroimaging characteristics and corresponding clinical phenotypes of autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A), a rare but severe neuroinflammatory disorder, to facilitate early diagnosis and appropriate treatment. METHODS: A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis)-conforming systematic review and meta-analysis was performed on all available data from January 2016 to June 2023. Clinical and neuroimaging phenotypes were extracted for both adult and paediatric forms. RESULTS: A total of 93 studies with 681 cases (55% males; median age = 46, range = 1-103 years) were included. Of these, 13 studies with a total of 535 cases were eligible for the meta-analysis. Clinically, GFAP-A was often preceded by a viral prodromal state (45% of cases) and manifested as meningitis, encephalitis, and/or myelitis. The most common symptoms were headache, fever, and movement disturbances. Coexisting autoantibodies (45%) and neoplasms (18%) were relatively frequent. Corticosteroid treatment resulted in partial/complete remission in a majority of cases (83%). Neuroimaging often revealed T2/fluid-attenuated inversion recovery (FLAIR) hyperintensities (74%) as well as perivascular (45%) and/or leptomeningeal (30%) enhancement. Spinal cord abnormalities were also frequent (49%), most commonly manifesting as longitudinally extensive myelitis. There were 88 paediatric cases; they had less prominent neuroimaging findings with lower frequencies of both T2/FLAIR hyperintensities (38%) and contrast enhancement (19%). CONCLUSIONS: This systematic review and meta-analysis provide high-level evidence for clinical and imaging phenotypes of GFAP-A, which will benefit the identification and clinical workup of suspected cases. Differential diagnostic cues to distinguish GFAP-A from common clinical and imaging mimics are provided as well as suitable magnetic resonance imaging protocol recommendations.

Rituximab treatment in pediatric-onset multiple sclerosis.

BACKGROUND AND PURPOSE: Rituximab (RTX) is frequently used off-label in multiple sclerosis. However, studies on the risk-benefit profile of RTX in pediatric-onset multiple sclerosis are scarce. METHODS: In this multicenter retrospective cohort study, patients with pediatric-onset multiple sclerosis from Sweden, Austria and Germany, who received RTX treatment were identified by chart review. Annualized relapse rates, Expanded Disability Status Scale scores and magnetic resonance imaging parameters (new T2 lesions and contrast-enhancing lesions) were assessed before and during RTX treatment. The proportion of patients who remained free from clinical and disease activity (NEDA-3) during RTX treatment was calculated. Side effects such as infusion-related reactions, infections and laboratory abnormalities were assessed. RESULTS: Sixty-one patients received RTX during a median (interquartile range) follow-up period of 20.9 (35.6) months. The annualized relapse rate decreased from 0.6 (95% confidence interval [CI] 0.38-0.92) to 0.03 (95% CI 0.02-0.14). The annual rate of new T2 lesions decreased from 1.25 (95% CI 0.70-2.48) to 0.08 (95% CI 0.03-0.25) and annual rates of new contrast-enhancing lesions decreased from 0.86 (95% CI 0.30-3.96) to 0. Overall, 70% of patients displayed no evidence of disease activity (NEDA-3). Adverse events were observed in 67% of patients. Six patients discontinued treatment due to ongoing disease activity or adverse events. CONCLUSION: Our study provides class IV evidence that RTX reduces clinical and radiological activity in pediatric-onset multiple sclerosis.

Autoimmune Encephalitis with Autoantibodies to NMDAR1 following Herpes Encephalitis in Children and Adolescents.

Herpes simplex virus (HSV) type 1 is a frequent pathogen causing infectious encephalitis (HSVE). Early treatment with intravenous acyclovir has led to a significant decrease in mortality. However, especially in children, deterioration during or after HSVE may occur without any evidence of HSV reactivation or improvement following repeated antiviral therapy. Here, we report 15 patients (age range 3 months to 15 years) who suffered from autoimmune encephalitis with autoantibodies to NMDAR1 following Herpes encephalitis, presenting with movement abnormalities (young children) or neuropsychiatric symptoms (older children) as major complaints, respectively. The diagnosis was based on positive cerebrospinal fluid (CSF) and/or serum anti-NMDAR-antibodies with two children showing only positive CSF antibody findings. The time lag between first symptoms and diagnosis of autoimmune encephalitis was significantly longer than between first symptoms and diagnosis of HSVE (p <0.01). All patients improved during immunosuppressive treatment, during which plasmapheresis or rituximab treatments were applied in 11 patients, irrespective of their age. Despite immunotherapy, no patients relapsed with HSVE. Early diagnosis and treatment of autoimmune encephalitis after HSVE may be associated with a better outcome so that high clinical awareness and routine testing for anti-NMDAR-antibodies after HSVE seems advisable. If autoimmune encephalitis is suspected, antibody testing should also be performed on CSF if negative in serum.

International consensus recommendations for management of New Onset Refractory Status Epilepticus (NORSE) incl. Febrile Infection-Related Epilepsy Syndrome (FIRES): Statements and Supporting Evidence.

OBJECTIVE: To develop consensus-based recommendations for the management of adult and paediatric patients with NORSE/FIRES based on best evidence and experience. METHODS: The Delphi methodology was followed. A facilitator group of 9 experts was established, who defined the scope, users and suggestions for recommendations. Following a review of the current literature, recommendation statements concerning diagnosis, treatment and research directions were generated which were then voted on a scale of 1 (strongly disagree) to 9 (strongly agree) by a panel of 48 experts in the field. Consensus that a statement was appropriate was reached if the median score was greater or equal to 7, and inappropriate if the median score was less than or equal to 3. The analysis of evidence was mapped to the results of each statement included in the Delphi survey. RESULTS: Overall, 85 recommendation statements achieved consensus. The recommendations are divided into five sections: 1) disease characteristics, 2) diagnostic testing and sampling, 3) acute treatment, 4) treatment in the post-acute phase, and 5) research, registries and future directions in NORSE/FIRES. The detailed results and discussion of all 85 statements are outlined herein. A corresponding summary of findings and practical flowsheets are presented in a companion article. SIGNIFICANCE: This detailed analysis offers insight into the supporting evidence and the current gaps in the literature that are associated with expert consensus statements related to NORSE/FIRES. The recommendations generated by this consensus can be used as a guide for the diagnosis, evaluation, and management of patients with NORSE/FIRES, and for planning of future research.

International consensus recommendations for management of New Onset Refractory Status Epilepticus (NORSE) including Febrile Infection-Related Epilepsy Syndrome (FIRES): Summary and Clinical Tools.

OBJECTIVE: To develop consensus-based recommendations for the management of adult and pediatric patients with NORSE/FIRES based on best available evidence and expert opinion. METHODS: The Delphi methodology was followed. A facilitator group of 9 experts was established, who defined the scope, users and suggestions for recommendations. Following a review of the current literature, recommendation statements concerning diagnosis, treatment and research directions were generated which were then voted on a scale of 1 (strongly disagree) to 9 (strongly agree) by a panel of 48 experts in the field. Consensus that a statement was appropriate was reached if the median score was greater than or equal to 7, and inappropriate if the median score was less than or equal to 3. RESULTS: Overall, 85 recommendation statements achieved consensus. The recommendations are divided into five sections: 1) disease characteristics, 2) diagnostic testing and sampling, 3) acute treatment, 4) treatment in the post-acute phase, and 5) research, registries and future directions in NORSE/FIRES. These are summarized in this article along with two practical clinical flowsheets: one for diagnosis and evaluation and one for acute treatment. A corresponding evidence-based analysis of all 85 recommendations alongside responses by the Delphi panel is presented in a companion article. SIGNIFICANCE: The recommendations generated by this consensus can be used as a guide for the diagnosis, evaluation, and management of patients with NORSE/FIRES, and for planning of future research.

Age-related changes in the inflammatory responses to viral infections in the central nervous system during childhood.

BACKGROUND: The developmental stages and function of immune cells in the central nervous system during infancy and childhood are poorly understood. We analyzed whether cytokine and chemokine profiles in children and adolescents with viral central nervous system infections were different depending on age. METHODS: The acute phase cerebrospinal fluid of 80 children (mean age 98 months, range 1-206 months) were analyzed for protein levels of interleukin-1ß (IL-1ß), IL-1-RA, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, IL-18, monocyte chemoattractant protein-1 (MCP-1), interferon (IFN) gamma-induced protein 10 (IP-10), IFN-γ, and macrophage migration inhibitory factor (MIF). RESULTS: We found an age-dependent increased expression of IL-4, IL-6, IL-13, MIF, IP-10, and IFN-γ and a decreased expression of MCP-1 and IL-15 in response to a viral infection of the central nervous system. In contrast, all other cytokines and chemokine were unaffected by the age of the patient. CONCLUSION: These findings demonstrate that the immunological response to a viral infection matures during childhood and adolescence. This may in turn be of importance for the outcome of a viral infection and the risk for subsequent sequela. It also demonstrates that age is a factor that needs to be considered when using cytokines and chemokines as biomarkers for infections in the central nervous system. IMPACT: The immunological response to a viral infection matures during childhood and adolescence. This may be of importance for the outcome of a viral infection and the risk for subsequent sequela. It also demonstrates that age is a factor that needs to be considered when using cytokines and chemokines as biomarkers for infections in the central nervous system.

Deciphering the TLR transcriptome and downstream signaling pathway in cerebrospinal fluid in pediatric meningitis.

OBJECTIVE/DESIGN: Pediatric meningitis is characterized by a colossal inflammatory response to the pathogen in the central nervous system (CNS). This unabated inflammatory response persists even after the removal of the pathogen by antibiotics/steroids causing collateral damage to CNS tissue. Toll-like receptors (TLRs) are the key players in the recognition and elicitation of innate-immune response against bacterial/viral components in cerebrospinal fluid (CSF). Till date, the precise understanding of TLR-triggered inflammatory response in pediatric meningitis is lacking. The present study was designed to delineate the role of TLR transcriptome and downstream signaling pathways in CSF of pediatric meningitis. METHODS: Children in the age group of > 3 months to 12 years with pediatric meningitis were included. A total of 249 cases of pediatric meningitis (bacterial = 89, viral = 160) were included. In addition, 71 children who tested negative to the pathogen in CSF tap and did not have signs of infection clinically constituted the controls. RNA was extracted from the CSF samples of both cases and controls. The relative gene expression profile of 42 TLR signaling pathway genes was performed. For the analysis of secretory cytokines and chemokines in CSF, Luminex assay was performed. RESULTS: We report global upregulation of TLR genes in patients with acute bacterial meningitis (ABM). The downstream signaling molecules were upregulated as well. The CSF of pediatric ABM patients revealed a predominant pro-inflammatory milieu marked by increased levels of pro-inflammatory cytokines. A significant correlation between poor clinical outcomes of patients and an increased expression of TLR/pro-inflammatory cytokine genes was observed. CONCLUSION: Our findings provide support for future studies exploring TLR-based adjunct therapy to limit the neurological sequelae, owing to persistent inflammation in pediatric ABM patients.

Validation of central nervous system-induced seizures and other neurological variables in the Swedish Neonatal Quality Register.

AIM: We sought to validate neurological variables and relevant International Classification of Diseases, Tenth Revision (ICD-10) codes in the Swedish Neonatal Quality (SNQ) Register. METHODS: Register data were collected for 351 neonates, born between January 2009 and December 2016, who were treated at a neonatal unit in the Stockholm region on 385 occasions. They were eligible if the check-box for central nervous system (CNS)-induced seizures was ticked. The Register data, including relevant ICD-10 codes, were validated by checking the patients' electronic medical charts. RESULTS: Most of the neonates were born at term (76%) and weighed >2500 g (80%). The variable CNS-induced seizures had a positive predictive value of 46%. The ICD-10 diagnosis P90.9A had a positive predictive value of 90%. This comprises seizures validated with electroencephalography, amplitude-integrated electroencephalography or continuous function monitoring. The majority of the associated neurological variables in the Register had positive predictive values above 85%. CONCLUSION: When the check-box was ticked for central nervous system-induced seizures, most of the neurological variables in the Register had high validity. However, the CNS-induced seizures variable per se had a lower positive predictive value. Future SNQ Register-based studies of such neonatal seizures should also include ICD-10 P90.9A.

Clinical and Magnetic Resonance Imaging Outcome Predictors in Pediatric Anti-N-Methyl-D-Aspartate Receptor Encephalitis.

OBJECTIVE: To evaluate disease symptoms, and clinical and magnetic resonance imaging (MRI) findings and to perform longitudinal volumetric MRI analyses in a European multicenter cohort of pediatric anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) patients. METHODS: We studied 38 children with NMDARE (median age = 12.9 years, range =1-18) and a total of 82 MRI scans for volumetric MRI analyses compared to matched healthy controls. Mixed-effect models and brain volume z scores were applied to estimate longitudinal brain volume development. Ordinal logistic regression and ordinal mixed models were used to predict disease outcome and severity. RESULTS: Initial MRI scans showed abnormal findings in 15 of 38 (39.5%) patients, mostly white matter T2/fluid-attenuated inversion recovery hyperintensities. Volumetric MRI analyses revealed reductions of whole brain and gray matter as well as hippocampal and basal ganglia volumes in NMDARE children. Longitudinal mixed-effect models and z score transformation showed failure of age-expected brain growth in patients. Importantly, patients with abnormal MRI findings at onset were more likely to have poor outcome (Pediatric Cerebral Performance Category score > 1, incidence rate ratio = 3.50, 95% confidence interval [CI] = 1.31-9.31, p = 0.012) compared to patients with normal MRI. Ordinal logistic regression models corrected for time from onset confirmed abnormal MRI at onset (odds ratio [OR] = 9.90, 95% CI = 2.51-17.28, p = 0.009), a presentation with sensorimotor deficits (OR = 13.71, 95% CI = 2.68-24.73, p = 0.015), and a treatment delay > 4 weeks (OR = 5.15, 95% CI = 0.47-9.82, p = 0.031) as independent predictors of poor clinical outcome. INTERPRETATION: Children with NMDARE exhibit significant brain volume loss and failure of age-expected brain growth. Abnormal MRI findings, a clinical presentation with sensorimotor deficits, and a treatment delay > 4 weeks are associated with worse clinical outcome. These characteristics represent promising prognostic biomarkers in pediatric NMDARE. ANN NEUROL 2020 ANN NEUROL 2020;88:148-159.

Clinical guidance for diagnosis and management of suspected Pediatric Acute-onset Neuropsychiatric Syndrome in the Nordic countries.

Pediatric acute-onset neuropsychiatric syndrome is a clinical concept used to describe a subgroup of children with sudden onset of psychiatric and somatic symptoms. The diagnostic term and especially management of children differs depending on the clinical setting to which they present, and the diagnosis and management is controversial. The aim of this paper is to propose a clinical guidance including homogenous diagnostic work-up and management of paediatric acute onset neuropsychiatric syndrome within the Nordic countries. The guidance is authored by a Nordic-UK working group consisting of paediatric neurologist, child psychiatrists and psychologists from Denmark, Norway, Sweden and Great Britain, and is the result of broad consensus. CONCLUSION: Consensus was achieved in the collaboration on work-up and treatment of patients with paediatric acute-onset neuropsychiatric syndrome, which we hope will improve and homogenise patient care and enable future collaborative research in the field.

Variants in CHRNB2 and CHRNA4 Identified in Patients with Insular Epilepsy.

PURPOSE: Our purpose was to determine the role of CHRNA4 and CHRNB2 in insular epilepsy. METHOD: We identified two patients with drug-resistant predominantly sleep-related hypermotor seizures, one harboring a heterozygous missense variant (c.77C>T; p. Thr26Met) in the CHRNB2 gene and the other a heterozygous missense variant (c.1079G>A; p. Arg360Gln) in the CHRNA4 gene. The patients underwent electrophysiological and neuroimaging studies, and we performed functional characterization of the p. Thr26Met (c.77C>T) in the CHRNB2 gene. RESULTS: We localized the epileptic foci to the left insula in the first case (now seizure-free following epilepsy surgery) and to both insulae in the second case. Based on tools predicting the possible impact of amino acid substitutions on the structure and function of proteins (sorting intolerant from tolerant and PolyPhen-2), variants identified in this report could be deleterious. Functional expression in human cell lines of α4ß2 (wild-type), α4ß2-Thr26Met (homozygote), and α4ß2/ß2-Thr26Met (heterozygote) nicotinic acetylcholine receptors revealed that the mutant subunit led to significantly higher whole-cell nicotinic currents. This feature was observed in both homo- and heterozygous conditions and was not accompanied by major alterations of the current reversal potential or the shape of the concentration-response relation. CONCLUSIONS: This study suggests that variants in CHRNB2 and CHRNA4, initially linked to autosomal dominant nocturnal frontal lobe epilepsy, are also found in patients with predominantly sleep-related insular epilepsy. Although the reported variants should be considered of unknown clinical significance for the moment, identification of additional similar cases and further functional studies could eventually strengthen this association.

Standardised guidelines and reference networks for treating neuroinflammatory conditions in children are lacking.

AIM: To investigate whether local or national guidelines are used in treating neuroinflammatory conditions in children and if there is a perceived need for more guidelines and forums of cooperation. METHODS: A web-based questionnaire sent to all university hospitals in the Nordic countries (n = 21) between March and July 2015. RESULTS: All 21 centres replied to the survey. Markers of neuronal or glial damage and markers of inflammation were used at varying rates. Neuronal antibodies were used at all sites except two. Only three hospitals collaborated with their laboratories in developing new assays for biomarkers. Although most centres used some form of guideline for neuroinflammatory conditions, no single disease had a guideline prevalence over 60%. For some diagnoses, access to guidelines was as low as 10%. Standardised follow-up programs were lacking in 50-95%. A clear majority of the centres perceived a need for more guidelines. Also, forums of cooperation were few. However, there was a great interest in developing paediatric neuroinflammatory guidelines and to create platforms for further consensus work and discussion. CONCLUSION: There is a need for developing treatment guidelines within the field of paediatric neuroinflammation to aid in clinical decision-making, and to establish forums of cooperation.

Snus users had high levels of nicotine, cotinine and 3-hydroxycotinine in their breastmilk, and the clearance was slower than in smoking mothers.

AIM: Using snus, an oral moist tobacco, has increased among pregnant women in Sweden, the only European Union country where sales are legal. This study evaluated whether snus generated similar concentrations of nicotine and its metabolites in breastmilk to cigarette smoking. METHODS: We analysed 49 breastmilk samples from 33 nursing mother - 13 snus users, six cigarette smokers and 14 controls - for concentrations of nicotine, cotinine and 3-hydroxycotinine. The mothers were recruited at antenatal clinics in Sweden from 2007 to 2012. RESULTS: The median nicotine concentration in breastmilk of the snus users was 38.7 ng/mL (0-137) versus 24.0 ng/mL (0-56) in smokers, with median cotinine levels of 327.6 ng/mL (37-958) versus 164.4 ng/mL and median 3-hydroxycotinine levels of 202.7 ng/mL (28-452) versus 112.4 (0-231), respectively. Nicotine was still detected in the breastmilk of eight of the 13 snus users after abstaining from tobacco for a median duration of 11 hours (0.6-12.5), while the breastmilk of the smokers was nicotine-free after four hours' abstinence. CONCLUSION: Snus users had high levels of nicotine and metabolites in their breastmilk and nicotine was found even after 12.5 hours of abstinence.

High prevalence of pituitary hormone deficiency in both unilateral and bilateral optic nerve hypoplasia.

AIM: This study examined the prevalence of neurological impairment and pituitary hormone deficiency (PHD) in patients with unilateral and bilateral optic nerve hypoplasia (ONH). METHODS: A population-based cross-sectional cohort study of 65 patients (51% female) with ONH was conducted in Stockholm. Of these were 35 bilateral and 30 unilateral. The patients were below 20 years of age, living in Stockholm in December 2009 and found through database searching. The median age at the analysis of the results in January 2018 was 16.1 years (range 8.1-27.5 years). Neurological assessments and blood sampling were conducted, neuroradiology was reviewed and growth curves were analysed. Diagnoses of PHDs were based on clinical and biochemical evidence of hormone deficiency. RESULTS: Neurological impairments were identified in 47% of the patients and impairments in gross and fine motor function were more prevalent in bilateral ONH (p < 0.001). In addition, 9% had cerebral palsy and 14% had epilepsy. The prevalence of PHD was 29 and 19% had multiple PHD. CONCLUSION: Children with ONH had a high risk of neurological impairment, especially in bilateral disease. Both unilateral and bilateral ONH signified an increased prevalence of PHD and all these children should be endocrinologically followed up until completed puberty.

Moderate neonatal hypoglycemia and adverse neurological development at 2-6 years of age.

To determine whether moderate neonatal hypoglycemia in otherwise healthy infants is associated with adverse neurodevelopmental outcome in pre-school children. Population-based cohort study with prospectively collected register data from Sweden. All singletons born July 1st 2008 through December 31st 2012 (n = 101,060) in the region were included. Infants with congenital malformations, infants treated in neonatal intensive care unit, infants with inborn errors of metabolism and infants to mothers with diabetes were excluded. Infants were followed-up until 2014, at 2-6 years of age. Exposure was neonatal moderate hypoglycemia. Main outcomes were a compiled neurological or neurodevelopmental outcome; any developmental delay; motor developmental delay; and cognitive developmental delay. In adjusted regression analyses, the odds ratio (OR) of any neurological or neurodevelopmental outcome was 1.48 (95% confidence interval: 1.17-1.88) in hypoglycemic compared to normoglycemic infants. The adjusted risk of any developmental delay was more than doubled (OR 2.53 [1.71-3.73]), the adjusted risk of motor developmental delay was almost doubled (OR: 1.91 [1.06-3.44]) and the adjusted risk of cognitive developmental delay was almost tripled (OR 2.85 [1.70-4.76]). Infants with early neonatal hypoglycemia (< 6 h) had a double risk (OR 1.94 [1.30-2.89]) of any neurological or neurodevelopmental outcome and a tripled risk of cognitive developmental delay (OR 3.17 [1.35-7.43]), compared to normoglycemic infants. In the first population-based study on this topic, we show that moderate neonatal hypoglycemia is associated with increased risks of impaired neurodevelopment. Current treatment routines for uncomplicated hypoglycemia should be followed.

Maternal snuff use and cotinine in late pregnancy-A validation study.

INTRODUCTION: Oral moist snuff is widely used in Sweden including during pregnancy. Maternal snuff use has been associated with increased risks of adverse pregnancy outcomes in epidemiological studies. Self-reported maternal snuff use has not been validated previously. The main objective of this study was to validate self-reported snuff use in pregnancy in a prospective cohort study and in the Medical Birth Register. MATERIAL AND METHODS: A prospective Swedish cohort study, 2005-2011, in which 572 women were asked to participate. Of 474 recruited women, 381 non-smokers (263 snuff users and 118 non-tobacco users) were included in the main analyses. Participants prospectively reported snuff use through questionnaires. Medical Birth Register data on the participants was obtained. Maternal urine cotinine was collected in late pregnancy and was used as a biomarker. RESULTS: Cotinine levels in maternal urine confirmed a high validity of self-reported snuff use through questionnaires in late pregnancy; sensitivity and specificity values were 98% and 96%, respectively. In the Medical Birth Register, 45% of the snuff users were misclassified as nonusers in late pregnancy. There were significant differences in median cotinine levels between users of mini pouches and users of standard pouches, but there was a great difference of cotinine levels among users with similar number of pouches used daily. CONCLUSIONS: Self-reported snuff use through questionnaires has high validity. In the Medical Birth Register, in late pregnancy, many snuff users were misclassified as nonusers. As a consequence, there is a risk of underestimating the harmful effects of snuff use when using late pregnancy Medical Birth Register data.

Children with optic nerve hypoplasia face a high risk of neurodevelopmental disorders.

AIM: Optic nerve hypoplasia (ONH) is a congenital ocular malformation that has been associated with neurodevelopmental disorders, but the prevalence in unilateral disease and less severe visual impairment is unknown. We studied intellectual disability and autism spectrum disorders (ASDs) in patients with ONH. METHODS: This was a population-based cross-sectional cohort study of 65 patients (33 female) with ONH below 20 years of age, living in Stockholm in December 2009, with data analysed in January 2016. Of these 35 were bilateral and 30 were unilateral. Neurodevelopmental disorders were diagnosed or confirmed by neurological assessments, the Five to Fifteen parent questionnaire and reviewing previous neuropsychological investigations or conducting neuropsychological tests. RESULTS: Bilateral ONH patients had lower mean full scale intelligence quotient scores than unilateral patients (84.4 and 99.4, respectively, p = 0.049). We assessed intellectual disability in 55 eligible patients, and it was more common in patients with bilateral ONH (18 of 32, 56%) than unilateral ONH (two of 23, 9%, p < 0.001). ASDs were diagnosed in seven of 42 (17%) patients. CONCLUSION: Children with bilateral ONH had a high risk of neurodevelopmental disorders, especially intellectual disability. The risk was lower in unilateral ONH, but the levels of neurodevelopmental disorders warrant screening of both groups.

Cerebrospinal fluid kynurenine and kynurenic acid concentrations are associated with coma duration and long-term neurocognitive impairment in Ugandan children with cerebral malaria.

BACKGROUND: One-fourth of children with cerebral malaria (CM) retain cognitive sequelae up to 2 years after acute disease. The kynurenine pathway of the brain, forming neuroactive metabolites, e.g. the NMDA-receptor antagonist kynurenic acid (KYNA), has been implicated in long-term cognitive dysfunction in other CNS infections. In the present study, the association between the kynurenine pathway and neurologic/cognitive complications in children with CM was investigated. METHODS: Cerebrospinal fluid (CSF) concentrations of KYNA and its precursor kynurenine in 69 Ugandan children admitted for CM to Mulago Hospital, Kampala, Uganda, between 2008 and 2013 were assessed. CSF kynurenine and KYNA were compared to CSF cytokine levels, acute and long-term neurologic complications, and long-term cognitive impairments. CSF kynurenine and KYNA from eight Swedish children without neurological or infectious disease admitted to Astrid Lindgren's Children's Hospital were quantified and used for comparison. RESULTS: Children with CM had significantly higher CSF concentration of kynurenine and KYNA than Swedish children (P < 0.0001 for both), and CSF kynurenine and KYNA were positively correlated. In children with CM, CSF kynurenine and KYNA concentrations were associated with coma duration in children of all ages (P = 0.003 and 0.04, respectively), and CSF kynurenine concentrations were associated with worse overall cognition (P = 0.056) and attention (P = 0.003) at 12-month follow-up in children ≥5 years old. CONCLUSIONS: CSF KYNA and kynurenine are elevated in children with CM, indicating an inhibition of glutamatergic and cholinergic signaling. This inhibition may lead acutely to prolonged coma and long-term to impairment of attention and cognition.