Adeno-associated virus serotype 9 antibody titers in patients with SMA pre-screened for treatment with onasemnogene abeparvovec -routine care evidence.

Spinal muscular atrophy (SMA) is characterized by progressive weakness of skeletal and respiratory muscles. This study aimed to evaluate the prevalence of pre-existing anti adeno-associated virus serotype 9 antibody (AAV9-Ab) titers among infantile-onset SMA diagnosed infants pre-screened for treatment with AAV9-based onasemnogene abeparvovec, and to explore whether clinical and/or demographic characteristics are correlated with AAV9 Ab test results. This is a retrospective multicenter study of children diagnosed with 5q SMA younger than two years of age. The obtained data included demographic data, SMA type, SMN2 gene copy number, onset date, and results of AAV9-Ab test and of SMA prior treatments. Thirty-four patients were enrolled; six patients had positive results of AAV9-Ab (titer > 1:50) in the initial screening, 15 patients were re-tested for AAV9-Abs, of whom, three patients had seroreverted [1.5-4.5 months] between the two AAV9-Abs tests. One patient had seroconverted (5.5 months after the first AAV9-Abs test). The remaining 11 patients presented matching titer results in the two tests. No demographic/clinical factors were correlated to high AAV9-Abs titers (P > 0.05).We recommend AAV9-Ab re-tests to be performed until the age of 8 months, or, if 1.5 months or more have passed after the initial AAV9-Abs test.

Variants in SCAF4 Cause a Neurodevelopmental Disorder and Are Associated with Impaired mRNA Processing.

RNA polymerase II interacts with various other complexes and factors to ensure correct initiation, elongation, and termination of mRNA transcription. One of these proteins is SR-related CTD-associated factor 4 (SCAF4), which is important for correct usage of polyA sites for mRNA termination. Using exome sequencing and international matchmaking, we identified nine likely pathogenic germline variants in SCAF4 including two splice-site and seven truncating variants, all residing in the N-terminal two thirds of the protein. Eight of these variants occurred de novo, and one was inherited. Affected individuals demonstrated a variable neurodevelopmental disorder characterized by mild intellectual disability, seizures, behavioral abnormalities, and various skeletal and structural anomalies. Paired-end RNA sequencing on blood lymphocytes of SCAF4-deficient individuals revealed a broad deregulation of more than 9,000 genes and significant differential splicing of more than 2,900 genes, indicating an important role of SCAF4 in mRNA processing. Knockdown of the SCAF4 ortholog CG4266 in the model organism Drosophila melanogaster resulted in impaired locomotor function, learning, and short-term memory. Furthermore, we observed an increased number of active zones in larval neuromuscular junctions, representing large glutamatergic synapses. These observations indicate a role of CG4266 in nervous system development and function and support the implication of SCAF4 in neurodevelopmental phenotypes. In summary, our data show that heterozygous, likely gene-disrupting variants in SCAF4 are causative for a variable neurodevelopmental disorder associated with impaired mRNA processing.

Trametinib for orbital plexiform neurofibromas in young children with neurofibromatosis type 1.

INTRODUCTION: Plexiform neurofibromas (PNF) in neurofibromatosis type 1 (NF1) are usually diagnosed in childhood and can grow rapidly during this period. In 10% of patients, PNF involve the orbital-periorbital area and may cause visual problems including glaucoma, visual loss from amblyopia (deprivational, strabismic, or refractive), optic nerve compression, or keratopathy. Ptosis, proptosis, and facial disfigurement lead to social problems and decreased self-esteem. Complete surgical removal involves significant risks and mutilation, and regrowth after debulking is not uncommon. Inhibitors of the RAS/MAPK pathway have recently been investigated for their activity in PNF. We administered the oral MEK inhibitor trametinib to five young children with NF1 and PNF of the orbital area, with visual compromise and progressive tumor growth; and followed them clinically and by volumetric MRI. METHODS: Treatment was initiated at a mean age of 26.8 months (SD ± 12.8) and continued for a median 28 months (range 16-51). Doses were 0.025 mg/kg/day for children aged > 6 years and 0.032 mg/kg/day for those aged < 6 years. RESULTS: Volumetric MRI measurements showed a reduction of 2.9-33% at 1 year after treatment initiation, with maximal reductions of 44% and 49% in two patients, at 44 and 36 months, respectively. No change in visual function was recorded during treatment. One child reported decreased orbital pain after 2 weeks; and another, with involvement of the masseters, had increased ability to chew food. Toxicities were mostly to skin and nails, grades 1-2. CONCLUSIONS: Trametinib can decrease tumor size in some young children with orbital PNF and may prevent progressive disfigurement.

The great mimicker: Phenotypic overlap between constitutional mismatch repair deficiency and Tuberous Sclerosis complex.

Constitutional mismatch repair deficiency is a rare cancer predisposition syndrome caused by biallelic mutations in one of the four mismatch repair genes. Patients are predisposed to various tumors including hematological malignancies, brain tumors and colorectal carcinomas. Phenotypic overlap with Neurofibromatosis-1 is well known, with most patients presenting with café-au-lait macules. Other common features include axillary and/or inguinal freckling and intracranial MRI foci of high T2W/FLAIR signal intensity similar to the typical FASI seen in Neurofibromatosis-1. In this cohort of eight patients with constitutional mismatch repair deficiency we describe overlapping phenotypical features with Tuberous Sclerosis complex. In addition to "ash-leaf like" hypomelanotic macules (five patients), we detected intracranial tuber-like lesions (three patients), renal cysts (three patients) and renal angiomyolipomas (two patients). All our patients also had Neurofibromatosis-1 like features, mainly café-au-lait macules. This study suggests that features of Tuberous sclerosis especially when overlapping with those of Neurofibromatosis 1 or malignancies atypical for these syndromes should raise the possibility of constitutional mismatch repair deficiency. Correct diagnosis is essential for appropriate genetic counseling and pre-emptive cancer surveillance.

Evolution of EEG Findings in Pontocerebellar Hypoplasia Type 2A: Normal EEG in the First Few Months followed by Abnormal Tracing over the Years.

Pontocerebellar hypoplasia (PCH) is an autosomal recessive neurodevelopmental and neurodegenerative disorder characterized by cerebellar and pontine hypoplasia, progressive microcephaly, and developmental delay. Ten types of PCH have been described; PCH type 2A (PCH2A) due to a mutation in TSEN54 is the most frequent. Seizures have been reported in the large majority of patients. The probability of epilepsy developing increases with age, along with difficulties in differentiating seizures from dyskinetic movements. The aim of the present report was to describe the clinical symptoms and electroencephalogram (EEG) changes over time in three patients of Israeli Arab origin with PCH2A. All three, including two siblings and their first cousin, were homozygous for the TSEN54 p.A304S mutation. The patients demonstrated profound psychomotor retardation, severe spasticity and contractures, choreoathetoid movements, and seizures. The magnetic resonance imaging (MRI) scans and EEGs were reviewed by an experienced neuroradiologist and epileptologist, respectively. The MRI scans revealed a dragonfly-like cerebellar pattern in all patients. Despite the normal early EEG findings, all patients had characteristic features of epilepsy, with tonic seizures starting in the first days to months followed by focal to bilateral tonic-clonic seizures in early childhood which continued to adolescence. In conclusion, patients with PCH2A due to the missense mutation p.A304S in TSEN54 exhibit profound psychomotor delay, movement disorders, and intractable epilepsy. An evolution of EEG abnormalities and seizure semiology occurs over time. Similar to several other genetic epileptic encephalopathies, the normal early EEG tracing does not rule out the later occurrence of epilepsy.

Handwriting in children with Attention Deficient Hyperactive Disorder: role of graphology.

BACKGROUND: Handwriting difficulties are common in children with attention deficient hyperactive disorder (ADHD). The aim of our study was to find distinctive characteristics of handwriting in children with ADHD by using graphology to analyze physical characteristics and patterns, and to evaluate whether graphological analysis is an effective ADHD diagnostic tool for clinicians. METHOD: The cohort included 49 children aged 13-18 years attending a tertiary neurology and epilepsy center in 2016-2017; 22 had a previous DSM-IV/V diagnosis of ADHD. The children were asked to write a 10-12-line story in Hebrew on a blank sheet of paper with a blue pen over a 20-min period. The samples were analyzed by a licensed graphologist blinded to the clinical details of the children against a predetermined handwriting profile of individuals with ADHD. Each ADHD characteristic identified in each sample was accorded 1 point, up to a total of 15 points. Patients with a graphology score of 9-15 were considered to have ADHD. RESULTS: There were 21 boys (43%) and 28 girls (57%) in the cohort; 15 boys (71.4%) and 7 girls (25%) had a DSM-IV/V diagnosis of ADHD. The mean graphology score was significantly higher in the children who had a DSM-IV/V diagnosis of ADHD than in the children who did not (9.61 + 3.49 vs. 5.79 + 4.01, p = 0.002, respectfully). Using a score of 9 as the cutoff, in the girls, graphology had a specificity of 80% (95% CI 59.2-92.8) and a of sensitivity 71.4% for predicting ADHD. Corresponding values in the boys were 75.0 and 76.2%. CONCLUSION: The handwriting of children with ADHD has specific characteristics. Graphology may serve as a clinically useful tool in the diagnosis of ADHD.

Polymicrogyria and myoclonic epilepsy in autosomal recessive cutis laxa type 2A.

Cutis laxa syndromes are rare inherited disorders of skin and connective tissue metabolism associated with variable systemic involvement. The main clinical manifestation is loose, wrinkled, redundant, inelastic skin, hypotonia, typical facies including short nose and down-slanting palpebral fissures, and varying degrees of developmental delay. The aim of this report is to describe two siblings diagnosed with a moderate form of ATP6V0A2-related cutis laxa with polymicrogyria (cobblestone-like brain dysgenesis). One of the patients has myoclonic epilepsy which may have contributed to his more severe clinical presentation. The literature on cutis laxa syndromes is reviewed.

Brain imaging findings and social/emotional problems in Israeli children with neurofibromatosis type 1.

UNLABELLED: A potential association between brain MRI findings and social/emotional difficulties in children with neurofibromatosis type 1 (NF1) was examined. Twenty-eight children with NF1 filled in the Strengths and Difficulties Questionnaire (SDQ), and possible associations between their responses and findings in their brain MRI were sought. T2 bright foci were identified in MRI scans of 24 patients (85 %). There were no associations between the presence of the bright foci in any specific brain region and any of the SDQ scores for the emotional/behavioral measures. Male patients had significantly abnormal SDQ scores and peer problems. Patients with abnormal SDQ scores were younger than those with normal SDQ scores (mean 13.2 years vs 14.3 years, respectively; p = 0.23). A comparison of the scores obtained in ours and in another group of 11 children with NF1 yielded a significant difference between the groups. CONCLUSION: We believe that the lack of correlation between the MRI findings and the social/emotional parameters of the SDQ is another demonstration of the marked clinical variability characteristic of NF1.

Christianson syndrome: spectrum of neuroimaging findings.

Christianson syndrome (CS) is caused by mutations in SLC9A6 and is characterized by severe intellectual disability, absent speech, microcephaly, ataxia, seizures, and behavioral abnormalities. The clinical phenotypes of CS and Angelman syndrome (AS) are similar. Differentiation between CS and AS is important in terms of genetic counseling. We report on two children with CS and confirmed mutations in SLC9A6 focusing on neuroimaging findings and review the available literature. Cerebellar atrophy (CA) occurs in approximately 60% of the patients with CS and develops after the age of 12 months. Hyperintense signal of the cerebellar cortex (CbC) is less common, and may be diffuse, patchy, or involve only the inferior part of the cerebellum and is best seen on coronal fluid attenuation inversion recovery images. CA and CbC-hyperintensity are not neuroimaging features of AS. In a child with the phenotype of AS, CA and/or CbC-hyperintensity are rather specific for CS and should prioritize sequencing of SLC9A6.

Prospective, Cross-Sectional Study Finds No Common Viruses in Cerebrospinal Fluid of Children with Pseudotumor Cerebri.

Pseudotumor cerebri (PTC) in children is a rare condition whose underlying cause remains largely unknown. No study has yet systematically examined viral infection as a cause of PTC. The current study aimed to characterize PTC in children and investigate the possible role of acute viral infection of the central nervous system in its pathogenesis. A prospective, cross-sectional study was conducted in three centers in Israel. Participants were 50 children aged 0.5-18 years, of whom 27 had a definitive diagnosis of pseudotumor cerebri (the study group) and 23 comprised a control. Data collected included clinical presentation, imaging, treatment, ophthalmic findings, and cerebrospinal fluid (CSF) analysis. Using the ALLPLEXTM meningitis panel, real-time polymerase chain reaction (PCR) was used to test for the presence of 12 common viruses. PTC patients (mean age 12 ± 4.3 years; 14 males, 13 females) had mean opening pressure of 41.9 ±10.2 mmH2O. All PTC patients had papilledema, and 25 (93%) had PTC symptoms. No viruses were found in the PTC group, while in the control group, one patient tested positive for Epstein-Barr virus and another for human herpesvirus type 6. Overall, in our study, PTC was not found to be associated with the presence of viruses in CSF.

High CCL2 Levels Detected in CSF of Patients with Pediatric Pseudotumor Cerebri Syndrome.

Pseudotumor cerebri (PTC) is a disorder characterized by increased intracranial pressure in the absence of a structural lesion or other identifiable cause. Cytokines, which are involved in the regulation of immune responses and inflammation, have been implicated in the pathogenesis of PTC. In a prospective, cross-sectional study at three centers in Israel, we analyzed cerebrospinal fluid (CSF) samples from 60 children aged 0.5-18 years, including 43 children with a definitive diagnosis of PTC and a control group of 17 children. Levels of IL-4, IL-10, IL-17, CCL2, CCL7, CCL8, CCL13, BDNF, and IFN-γ were measured using ELISA kits. Levels of CCL2 were significantly higher in the PTC group compared to the control group (p < 0.05), with no other significant differences in the measured cytokines between the two groups. The groups did not differ significantly in clinical presentation, imaging, treatment, or ophthalmic findings. Our findings provide preliminary evidence that CCL2 may be involved in the pathogenesis of PTC and may serve a potential target for therapy in PTC.

Migraine abortive treatment in children and adolescents in Israel.

Migraine headaches in children may cause attacks that require abortive treatment. This study evaluated the incidence and efficacy of medications used for relieving migraine headache attacks in the pediatric population in Israel. Children 6-18 years of age who were diagnosed in our pediatric neurology clinic as having migraine headaches were enrolled into the study. Children and their parents recorded the children response to abortive treatment during consecutive migraine attacks. Fifty children, with 116 migraine attacks, were included in the study (30 females; mean age 12; range 6-18). Forty-seven (94%) reported on abortive treatment on the first migraine attack, 43 (86%) on a second migraine attack and 26 (52%) on a third migraine attack. During the first recorded migraine attack, 41 children (87.5%) reported taking only one type of medication for each headache episode, mainly ibuprofen or acetaminophen; less than a quarter used dipyrone (metamizol). Overall the improvement rate after two hours was 65.4% ± 27 for ibuprofen, 59.8 ± 35.3 for acetaminophen and 50.9 ± 27.4 for dipyrone without statistical difference. However, in the first recorded headache episode, males had a significantly better response to acetaminophen, compared to ibuprofen (95% ± 28 vs 75 ± 20). In conclusion, Children with migraine in Israel mainly use a single medication for each headache episode. Ibuprofen is the most commonly used abortive treatment; however, acetaminophen was associated with a better response among some of our patients.

Impairments in communication and social interaction in children with neurofibromatosis type 1: Characteristics and role of ADHD and language delay.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a multisystem neurocutaneous disorder with increased risk of tumor formation and higher incidence of autism spectrum disorder (ASD) than the general population. The aim of the study was to assess the presence of ASD symptoms in young children with NF1 and to examine their potential association with attention deficit hyperactivity disorder (ADHD) and speech delay. METHODS: The cohort included 30 patients with NF1 attending the multidisciplinary NF1 clinic of a tertiary pediatric medical center from September 2015 through September 2016. The parents/caregivers completed the Social Communication Questionnaire (SCQ) and the Vineland Adaptive Behavior Scales (VABS II). RESULTS: Sixteen patients (53%) had a previous diagnosis of ADHD. There was a positive association between the presence of ADHD and a low score on the VABS II interpersonal relationships subscale of the Socialization domain. Language delay, documented in 12 children (40%), also correlated with a low interpersonal relationships score. CONCLUSIONS: ADHD appears to be more a marker than an actual independent risk factor of ASD in NF1. The early evaluation of children with NF1 for interpersonal communication problems and ASD, especially those with a speech delay or ADHD, will alert clinicians to initiate appropriate and timely treatment.

Rolandic Epilepsy - A Silent Enemy. An Instructive Case.

A child is described who was followed in our clinic due to attention deficit hyperactivity disorder (ADHD) and was found to have the following list of diagnoses: mild developmental delay, motor tics, learning disability, selective mutism and autistic-like features. These disorders became manifest and were diagnosed over a period of several years in the above-noted order. He never had seizures. Medical evaluation, which was initiated due to his learning disability, was negative. The last test which was done was EEG, and this revealed a very active picture compatible with Rolandic epilepsy. Eventually, this was the key for the understanding of his whole clinical picture. It is suggested that in children with learning disability, the possibility of having seizure-free Rolandic epilepsy be considered early in the course of evaluation.

Behavioral Symptoms May Correlate With the Load and Spatial Location of Tubers and With Radial Migration Lines in Tuberous Sclerosis Complex.

Objective: Tuberous sclerosis complex (TSC) is a multisystem neurocutaneous genetic disorder. The clinical manifestations are extensive and include neurological, dermatological, cardiac, ophthalmic, nephrological, and neuropsychiatric manifestations. The prediction and pathophysiology of neuropsychiatric disorders such as emotional symptoms, conduct problems, hyperactivity, and poor social behavior are poorly understood. The aim of the study was to diagnose neuropsychiatric symptoms in individuals with TSC, and to examine their possible correlations with quantity, magnitude, and spatial location of tubers and radial migration (RM) lines. Methods: The cohort comprised 16 individuals with TSC, aged 5-29 years, with normal or low normal intelligence. The participants or their parents were requested to fill Strengths and Difficulties Questionnaire (SDQ) and the TAND (TSC-associated neuropsychiatric disorders) Checklist for assessment of their neuropsychiatric symptoms. Correlations were examined between these symptoms and the magnitude, quantities, and locations of tubers and white matter RM lines, as identified in T2/FLAIR brain MRI scans. Results: The SDQ score for peer relationship problems showed correlation with the tuber load (r = 0.52, p < 0.05). Tuber load and learning difficulties correlated significantly in the temporal and parietal area. Mood swings correlated with tubers in the parietal area (r = 0.529, p < 0.05). RM lines in the temporal area correlated with abnormal total SDQ (r = 0.51, p < 0.05). Anxiety and extreme shyness were correlated with RM lines in the parietal area, r = 0.513, p < 0.05 and r = 0.593, p < 0.05, respectively. Hyperactive/inattention correlated negatively with RM lines in the parietal area (r = -707, p < 0.01). Conclusions: These observations may lead to future studies for precise localization of neuropsychiatric symptoms, thereby facilitating directed therapy.

Optic Nerve Drusen Is Highly Prevalent Among Children With Pseudotumor Cerebri Syndrome.

Introduction: The clinical presentation of pseudotumor cerebri syndrome (PTCS) usually includes headache, nausea, and vomiting with normal physical examination apart from papilledema and diplopia. However, pseudopapilledema, which can be caused by optic nerve drusen, may lead to misdiagnosis. The prevalence of optic nerve drusen in the general population is 0.5-2%. The purpose of our study was to evaluate the prevalence and risk factors of optic nerve drusen among patients with PTCS. Materials and Methods: Medical records of children evaluated in the pediatric department at Bnai Zion Medical Center due to PTCS between 2008 and 2020 were assessed. Inclusion criteria were children age under 18 years with a PTCS diagnosis and ophthalmic B-mode ultrasonography (US). Exclusion criteria were secondary intracranial hypertension. Results: Thirty-four children were included with a mean age 10.1 years which included 50% boys. A majority of the patients, 24 (72.4%), complained of headaches, while 15 (45.5%) complained of transient visual obscuration, and 9 (26.5%) of vomiting. Visual acuity on presentation was normal (20/20-20/30) in 23 of the children (67%), moderately diminished (20/40-20/80) in 9 (26%), and showing profound loss (20/200) in 2 (7%). Five patients (14.7%) were diagnosed with optic nerve drusen via B-mode ophthalmic ultrasonography (US). However, they still fulfilled the diagnostic criteria for PTCS, and disc swelling improved after treatment. There were no statistically significant differences between the group with optic nerve drusen and the rest of the patients. Conclusions: Optic nerve drusen are common among pediatric patients with PTCS. Diagnosis of optic nerve drusen should not rule out the presence of increased intracranial pressure.

[Developmental manifestation in children with neurofibromatosis type 1].

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition that primarily involves the skin and the nervous system. It affects about 1 in 4000 individuals. NF1 is caused by a mutation in the nfl gene located on chromosome 17q11.2. Neurofibromin, the protein products of the normal nf1 gene, acts as a tumor suppressor and limits cell growth. Mutation in this gene leads to cell overgrowth and an increased risk of developing benign and malignant tumor. The diagnosis of NF1 is made in an individual with any two of the following clinical features: café-au-lait spots, intertriginous freckling, Lisch nodules, neurofibromas, optic glioma, distinctive bone lesions and first degree family relative with NF1. Learning and developmental disorders are the most common neurologic complication of neurofibromatosis type 1 and can be responsible for significant lifetime morbidity. This report provides a review on cognitive and developmental manifestation of children with NF1 and the importance of early diagnosis and treatment.

Prognostic Parameters of Acute Transverse Myelitis in Children.

Acute transverse myelitis is a rare and disabling disorder. Data on the imaging features in children are sparse. The aim of this study was to describe the clinical and magnetic resonance imaging findings characteristic of pediatric idiopathic acute transverse myelitis and to identify those with prognostic value. The database of a tertiary pediatric medical center was retrospectively reviewed for patients aged less than 18 years who were diagnosed in 2002-2017 with acute transverse myelitis that was not associated with recurrence of a demyelinating autoimmune event. Data were collected on clinical, laboratory, and imaging findings and outcome. A total of 23 children (11 male, 12 female) met the study criteria. Mean age at disease onset was 10 years, and mean duration of follow-up was 6 years 10 months. Spinal cord and brain magnetic resonance imaging scans were performed on admission or shortly thereafter. The most common finding was cross-sectional involvement, in 16 patients (70%). The mean number of involved spinal segments was 8. The most frequently involved region was the thoracic spine, in 17 patients (74%). Clinical factors predicting good prognosis were cerebrospinal fluid pleocytosis, absence of tetraparesis, and prolonged time to nadir. In conclusion, most children with acute transverse myelitis appear to have a good outcome. Prompt diagnosis and treatment are important. Further research is needed in a larger sample to evaluate the predictive value of imaging features.

Impact of a national population-based carrier-screening program on spinal muscular atrophy births.

Spinal muscular atrophy (SMA) is a genetic neurodegenerative disease. Population carrier screening for SMA was introduced in Israel in 2008 through health-care services' insurance plans and expanded to the entire Israeli population in 2013 by a national health program. The aim of the study was to evaluate the impact of carrier screening on reducing the rate of birth of infants with SMA. All cases of prenatal and postnatal diagnosis of SMA in 2008-2017 were identified from databases of relevant government organizations, genetic laboratories in medical centers, and health care systems in Israel. Since 2013, screening was performed in 309,352 individuals, of whom 5741 were found to be carriers (carrier rate 1:54). Given an average of 180,000 live births annually, the predicted rate of SMA diagnosis was 15 cases per year. Prior to 2013, the average rate of prenatally diagnosed SMA was 4.66 cases per year, compared with 7.75 cases per year following population-wide provision of screening. The annual rate of postnatally diagnosed cases remained steady since 2008, with an average of 7- 7.25 cases per year. Screening has been effective in increasing prenatal detection of SMA but has had no effect on the rate of confirmed postnatal diagnoses. We speculate that screening rates may be affected by social, cultural, and religious factors.

Attention Deficit Hyperactivity Disorder in Neurofibromatosis Type 1: Evaluation with a Continuous Performance Test.

BACKGROUND AND PURPOSE: The objective of this study was to determine if the MOXO visual- and vocal-distractors-based continuous performance test distinguishes patients with attention deficit hyperactivity disorder (ADHD) and neurofibromatosis type 1 (NF1) from those without NF1. METHODS: Thirty-five patients (16 males; mean age 9.91 years) attending a multidisciplinary NF1 clinic completed the MOXO test. The findings were compared to 532 healthy age-matched standardized control subjects (285 males) without ADHD. RESULTS: The overall performance in the MOXO text was significantly worse in the NF1 group than in controls (p<0.01), but no group-specific pattern was identified. Impulsivity and hyperactivity were significantly more prominent in males than females (p<0.01). Compared to controls, the NF1 group exhibited significantly more failures to respond to target stimuli in the presence of visual distractors. CONCLUSIONS: MOXO scores are abnormal in patients with NF1, but the test cannot differentiate between NF1 with ADHD characteristics and ADHD. The test highlights sex differences in ADHD characteristics in NF1. Overreactivity to visual distractors may form part of the attention deficit in NF1.