[Clinical and prognostic analysis of opsoclonus-myoclonus-ataxia syndrome in children].

Objective: To summarize the clinical and prognostic features of children with opsoclonus-myoclonus-ataxia syndrome (OMAS). Methods: A total of 46 patients who met the diagnostic criteria of OMAS in the Department of Neurology, Beijing Children's Hospital from June 2015 to June 2023 were retrospectively analyzed. Centralized online consultations or telephone visits were conducted between June and August 2023. The data of the children during hospitalization and follow-up were collected, including clinical manifestations, assistant examination, treatment and prognosis. According to the presence or absence of tumor, the patients were divided into two groups. The chi-square test or Mann-Whitney U test was used to compare the differences between the two groups. Univariate Logistic regression was used to analyze the factors related to OMAS recurrence and prognosis. Results: There were 46 patients, with 25 males and the onset age of 1.5 (1.2, 2.4) years. Twenty-six (57%) patients were diagnosed with neuroblastoma during the course of the disease, and no patients were categorized into the high-risk group. A total of 36 patients (78%) were followed up for≥6 months, and all of them were treated with first-line therapy with glucocorticoids, gammaglobulin and (or) adrenocorticotrophic hormone. Among the 36 patients, 9 patients (25%) were treated with second-line therapy for ≥3 months, including rituximab or cyclophosphamide, and 17 patients (47%) received chemotherapy related to neuroblastoma. At the follow-up time of 4.2 (2.2, 5.5) years, 10 patients (28%) had relapsed of OMAS. The Mitchell and Pike OMS rating scale score at the final follow-up was 0.5 (0, 2.0). Seven patients (19%) were mildly cognitively behind their peers and 6 patients (17%) were severely behind. Only 1 patient had tumor recurrence during follow-up. The history of vaccination or infection before onset was more common in the non-tumor group than in the tumor group (55%(11/20) vs. 23%(6/26), χ²=4.95, P=0.026). Myoclonus occurred more frequently in the non-tumor group (40%(8/20) vs. 4%(1/26), χ²=7.23, P=0.007) as the onset symptom. Univariate Logistic regression analysis showed that the tumor group had less recurrence (OR=0.19 (0.04-0.93), P=0.041). The use of second-line therapy or chemotherapy within 6 months of the disease course had a better prognosis (OR=11.64 (1.27-106.72), P=0.030). Conclusions: OMAS in children mostly starts in early childhood, and about half are combined with neuroblastoma. Neuroblastoma in combination with OMAS usually has a low risk classification and good prognosis. When comparing patients with OMAS with and without tumors, the latter have a more common infection or vaccination triggers, and myoclonus, as the onset symptom, is more common. Early addition of second-line therapy is associated with better prognosis in OMAS.

[Clinical characteristics and short-term prognosis of 22 cases with SARS-CoV-2 infection associated acute encephalopathy].

Objective: To investigate the clinical features and short-term prognosis of patients with SARS-CoV-2 infection associated acute encephalopathy (AE). Methods: Retrospective cohort study. The clinical data, radiological features and short-term follow-up of 22 cases diagnosed with SARS-CoV-2 infection associated AE in the Department of Neurology, Beijing Children's Hospital from December 2022 to January 2023 were retrospectively analyzed. The patients were divided into cytokine storm group, excitotoxic brain damage group and unclassified encephalopathy group according to the the clinicopathological features and the imaging features. The clinical characteristics of each group were analyzed descriptively. Patients were divided into good prognosis group (≤2 scores) and poor prognosis group (>2 scores) based on the modified Rankin scale (mRS) score of the last follow-up. Fisher exact test or Mann-Whitney U test was used to compare the two groups. Results: A total of 22 cases (12 females, 10 males) were included. The age of onset was 3.3 (1.7, 8.6) years. There were 11 cases (50%) with abnormal medical history, and 4 cases with abnormal family history. All the enrolled patients had fever as the initial clinical symptom, and 21 cases (95%) developed neurological symptoms within 24 hours after fever. The onset of neurological symptoms included convulsions (17 cases) and disturbance of consciousness (5 cases). There were 22 cases of encephalopathy, 20 cases of convulsions, 14 cases of speech disorders, 8 cases of involuntary movements and 3 cases of ataxia during the course of the disease. Clinical classification included 3 cases in the cytokine storm group, all with acute necrotizing encephalopathy (ANE); 9 cases in the excitotoxicity group, 8 cases with acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and 1 case with hemiconvulsion-hemiplegia syndrome; and 10 cases of unclassified encephalopathy. Laboratory studies revealed elevated glutathione transaminase in 9 cases, elevated glutamic alanine transaminase in 4 cases, elevated blood glucose in 3 cases, and elevated D-dimer in 3 cases. Serum ferritin was elevated in 3 of 5 cases, serum and cerebrospinal fluid (CSF) neurofilament light chain protein was elevated in 5 of 9 cases, serum cytokines were elevated in 7 of 18 cases, and CSF cytokines were elevated in 7 of 8 cases. Cranial imaging abnormalities were noted in 18 cases, including bilateral symmetric lesions in 3 ANE cases and "bright tree appearance" in 8 AESD cases. All 22 cases received symptomatic treatment and immunotherapy (intravenous immunoglobulin or glucocorticosteroids), and 1 ANE patient received tocilizumab. The follow-up time was 50 (43, 53) d, and 10 patients had a good prognosis and 12 patients had a poor prognosis. No statistically significant differences were found between the two groups in terms of epidemiology, clinical manifestations, biochemical indices, and duration of illness to initiate immunotherapy (all P>0.05). Conclusions: SARS-CoV-2 infection is also a major cause of AE. AESD and ANE are the common AE syndromes. Therefore, it is crucial to identify AE patients with fever, convulsions, and impaired consciousness, and apply aggressive therapy as early as possible.

[Analysis of clinical and imaging features of 6 cases of linear scleroderma en coup de sabre with central nervous system involvement in children].

Objective: To summarize the clinical and imaging features of linear scleroderma en coup de saber (LSCS) with central nervous system involvement in children. Methods: The clinical data(clinical manifestations and imaging features) of 6 children diagnosed with LSCS with central nervous system involvement who were admitted to Beijing Children's Hospital Affiliated to Capital Medical University from May 2019 to November 2021 were retrospectively analyzed. Results: The 6 patients were all female, aged 6.8 (3.3, 11.0) years at the time of diagnosis, and aged 3.0 (1.7, 4.1) years at the time of discovery of facial skin lesions. Facial skin lesions appeared before neurological symptoms in 5 cases, and neurological symptoms appeared 2 months before skin lesions in 1 case. All the patients had "sword wound" skin lesions on the forehead with alopecia. Neurological manifestations included epileptic seizures in 6 cases, focal neurological defects in 5 cases, and headaches in 2 cases. The intracranial lesions were all ipsilateral to the skin lesions. The magnetic resonance imaging (MRI) of 6 cases showed abnormal signals mainly involving white matter in 1 hemisphere, and 3 cases showed local encephalomalacia. The scattered low signal was observed in 5 cases on susceptibility weighted imaging. Localized brain parenchyma or leptomeninges enhancement was seen on Gadolinium-enhanced sequences in 5 cases. Scattered foci of calcification on the affected side were seen on cranial CT in 4 cases. Skin biopsy was performed in 2 cases. Part of the lesion of the brain was removed in 1 case, and the pathological findings suggested small vasculitis, which was consistent with skin pathological changes. All patients received symptomatic treatment with antiepileptic drugs. Oral prednisone combined with methotrexate was given in 4 cases, and 1 case was given oral prednisone only. One case was presumed to be in the resting stage of the disease due to significant cerebral atrophy in half of the brain, and only antiepileptic drugs were added. The patients were followed up for 6-36 months. The skin lesions of scleroderma and alopecia did not progress in 5 cases, and hemifacial atrophy was developed in 1 case, which was considered to be combined with Parry-Romberg syndrome. The seizures were controlled in 4 cases. One case had reduced seizure frequency but left hemiplegia. One patient still had intractable epilepsy and paroxysmal headache. Conclusions: LSCS with central nervous system involvement is more common in girls, with seizures and neurological defects as the main manifestations. Intracranial lesions are mostly ipsilateral to the skin lesions. Cerebral microbleeds, calcification, and encephalomalacia foci are common, and the pathological changes in skin and intracranial lesions are consistent with small-vessel vasculitis. Prednisone combined with methotrexate treatment has shown some efficacy, but some children remain with refractory epilepsy and neurological deficit symptoms.

[Analysis of clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion].

Objective: To investigate the clinical and genetic characteristics of epilepsy associated with chromosome 16p11.2 microdeletion. Methods: The patients (n=10) with 16p11.2 microdeletion found in children with epilepsy treated in Beijing Children's Hospital Affiliated to Capital Medical University from January 2018 to January 2021 were collected. The clinical manifestations, gene variations and prognosis were analyzed retrospectively. Results: A total of 10 children's data were collected, including 5 male and 5 female. The onset age of epilepsy was 4.5 (4.1,5.0) months. Regarding the seizure types, 7 cases had focal seizures with secondary generalization, 2 cases had generalized seizures, and 1 case had tonic seizures and spasms. Nine cases had cluster seizure attacks and 3 cases had status epilepticus. Seven cases had focal or multifocal epileptiform discharges in interictal electroencephalogram (EEG), 3 cases had borderline or normal EEG. Brain magnetic resonance imaging showed polymicrogyria in 1 case, paraventricular leukomalacia in 1 case, delayed myelination of white matter in 3 cases, and no obvious abnormalities in the other 5 cases. The patients were followed up for 0.5-3.5 years, with 1-3 kinds of antiepileptic drugs taken orally. The case with polymicrogyria still had seizures, however the other 9 cases had seizures controlled. The age of the last seizure attack was 8 (6, 12) months. There were 6 cases with mental and motor developmental delay before epilepsy onset. During the follow-up, 7 cases were retarded to varying degrees, while 3 cases had normal development. Regarding the genetic detection methods, 7 cases underwent whole exome sequencing, 2 cases underwent whole genome copy number variation detection, and 1 case underwent whole genome sequencing. The length of the 16p11.2 deletion in 10 cases ranged from 525 to 951 kb, and all contained the PRRT2 gene intact. Six cases were de novo variants, 1 case was inherited from the mother who had a history of convulsions in early childhood, and the source of variant was not verified in 3 cases, none of whose parents had relevant phenotype. Conclusions: The epilepsy associated with 16p11.2 microdeletion is mainly induced by the heterozygous deletion of PRRT2 gene in this region, however the phenotype is usually severe, and often combined with developmental and epileptic encephalopathy. Detection of copy number variation should be emphasized in children whose etiology is considered genetic but second-generation sequencing result is negative.

[The etiology of 340 infants with early-onset epilepsy].

Objective: To investigate the etiology of epilepsy onset before 6 months old and improve clinical understanding. Methods: The medical history, electroencephalogram, brain imaging, genetic examination and other clinical data of 340 patients who were diagnosed with epilepsy with onset under 6 months of age and were hospitalized in the Department of Neurology, Beijing Children's Hospital, Capital Medical University between January 2017 and December 2018 were retrospectively analyzed. Rank sum test was used to compare the ages of onset of different etiologic groups. Results: Of the 340 patients, 196 were males and 144 were females. The age of onset was 90.5 (48.0, 135.5) days. In the 250 (73.5%) underwent genetic test, 103 (41.2%) had pathogenic or likely pathogenic variants, involving 43 single gene variants and 2 chromosomal abnormalities. Seventy-nine patients (23.2%) had genetic etiology, 66 (19.4%) had structural etiology, 19 (5.6%) had metabolic etiology, 13 (3.8%) had multiple etiologies, and 163 (47.9%) had unknown etiology. In the 79 cases with genetic etiology, 30 single gene variants were detected, including 19 cases of PRRT2, 10 cases of KCNQ2, 7 cases of SCN1A, 6 cases of SCN2A, 6 cases of STXBP1, 5 cases of CDKL5, 2 cases of ARX, and 1 case of each of 23 gene variants. Two cases had chromosomal abnormalities which were 21-trisomy and 16p11.2 microdeletion syndrome respectively. Among the 66 cases with structural etiologies, 37 cases had acquired factors such as perinatal brain injury, 28 cases had congenital factors such as cortical malformation and 1 case was perinatal brain injury combined megalencephaly. The onset age of genetic etiology was 95 (26, 128) days, that of structural etiology was 90 (58, 30) days, and that of metabolic etiology was 57 (30, 90) days. The onset age of metabolic etiology was earlier than that of structural etiology (U=436.500, P=0.044). Conclusions: Genetic etiology is the most common defined etiology of infants with early-onset epilepsy aged 0-6 months, and there are certain differences in the age of onset between different etiologies. Proper application of genetic test is helpful to identify the etiology and guide treatment.

[Clinical and genetic analysis of 5 pediatric patients with hemiplegic migraine presenting as acute encephalopathy].

Objective: To analyze the clinical and genetic characteristics, diagnosis and treatment of hemiplegic migraine (HM) manifested as acute encephalopathy in children, so as to improve the understanding of this disease. Methods: The clinical data of 5 children diagnosed with HM characterized by acute encephalopathy who were admitted to Beijing Children's Hospital affiliated to Capital Medical University from August 2018 to June 2020 were retrospectively analyzed. Results: Among the 5 cases, 3 were males and 2 females with an age of 9.7 (3.9-12.7) years. The age of disease onset was 7.0(2.1-12.7) years. The peak symptoms of 5 children showed encephalopathy such as drowsiness and coma, as well as other clinical manifestations including headache, visual abnormality, hemiplegia, aphasia, convulsions, and fever, etc. The time to reach the peak was on the 2nd-6th day of the course of the disease. Before the onset of the disease 2 cases were found to have mild brain trauma and 2 cases had similar attacks in the past. Brain magnetic resonance imaging (MRI) showed hemispheric or partial cerebral cortex swelling and restricted diffusion of subcortical white matter in all cases, and cerebellar atrophy in 3 cases. All children received symptomatic treatment, and 2 of them were also treated with low-dose corticosteroids in the meantime. Finally all cases recovered clinically from the attack, but one had atrophic changes left in the affected area on brain MRI. Whole exon sequencing revealed variations of CACNA1A gene in all cases, among which 4 were de novo mutations and 1 case inherited from the mother who had migraine without aura. After the diagnosis, the 5 children were treated with long-term flunarizine and followed up for 22(7-29) months by telephone or in the outpatient clinic. Before the last follow-up, none of them showed weakness or encephalopathy, but one still had intermittent headaches and occasional transient right limb numbness. Conclusions: Hemipleg is often accompanied by impaired consciousness in addition to headache, hemiplegia, aphasia, visual abnormality, etc. Most patients recover completely after a short period, while a few recover slowly and may suffer sequelae such as brain atrophy and cognitive impairment and even death. CACNA1A gene variation is the most common genetic variation. Flunarizine could prevent recurrence of severe attack.

[Clinical features of anti-myelin oligodendrocyte glycoprotein antibody-associated diseases in children with cortical encephalitis].

Objective: To describe the clinical features of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-positive cortical encephalitis in children. Methods: Patients who were hospitalized in Beijing Children's Hospital from June 2018 to October 2019, with positive MOG antibodies and phenotype of cortical encephalitis were retrospectively analyzed. Cell-based assays (CBAs) were used to test MOG antibodies. Results: Five patients had the phenotype of cortical encephalitis during follow-up, with 3 females and 2 males. The age of onset ranged from 8 years to 12 years and 1 month. At the last follow-up, 3 cases exhibited a monophasic course and 2 cases were with relapse and remission courses. Six out of 8 episodes which had the phenotype of cortical encephalitis presented with seizures, among which 3 episodes had status epilepticus. None had recurrent seizures during remission. Other symptoms included fever (7/8), headache and vomiting (4/8), somnolence (3/8) and hemiplegia (1/8). Unilateral cortical swelling was observed in cerebral magnetic resonance imaging (MRI) of all patients, without any hemorrhage and necrosis. White blood cell (WBC) counts of cerebrospinal fluid increased, ranging from8×10(6)/L to 186×10(6)/L. All patients recovered well after treatment with intravenous immunogloblin and glucocorticoid. Two patients had relapses during follow-up and were additionally treated with mycophenolate mofetil. Conclusions: Anti-MOG antibodies can induce cortical encephalitis. In clinical setting, fever, headache and seizures are common, however, severe consciousness disturbance and local neurological deficits are rare in these patients. Cerebral MRI shows unilateral cortical swelling without any hemorrhage and necrosis. Usually, immunotherapy works well. No patients exist repeated seizures in remission, but some patients may have relapses.

[Clinical observation on the overlapping syndrome of myelin oligodendrocyte glycoprotein antibody and anti-N-methyl-D aspartate receptor in children].

Objective: To investigate the clinical features, imaging findings and prognosis of children with overlapping syndrome of myelin oligodendrocyte glycoprotein (MOG) antibody disease and anti-N-methyl-D aspartate receptor (NMDAR) encephalitis (MNOS). Methods: The clinical manifestations, immunological antibodies in blood and cerebrospinal fluid, cranial image, treatment and follow-up of 11 patients diagnosed as MNOS in the Department of Neurology, Beijing Children's Hospital from January 2011 to April 2019 were analyzed retrospectively. Results: A total of 11 patients, including 4 males and 7 females were analyzed, the age of onset was (10.4±2.3) years. A total of 29 episodes occurred in 11 children. At the last follow-up, 8 cases showed relapsed remission course, the interval of recurrence was 3 to 60 months. The onset symptoms of 11 patients included convulsions (10 cases), lethargy (6 cases), psychosis (6 cases). Among 29 episodes, the common symptoms were convulsions (16 episodes), psychosis (13 episodes),and lethargy (10 episodes). According to the diagnostic criteria of anti-NMDAR encephalitis and MOG-antibody disease, 29 episodes were divided into three phenotypes, including anti-NMDAR encephalitis(4 episodes), MOG-antibody diseases (10 episodes) and overlapping types (15 episodes).Twenty-seven times of acute stage cranial magnetic resonance imaging (MRI) were available, common lesions included cortical focus (22 times), subcortical white matter (7 times), brainstem (9 times). All patients were sensitive to first-line immunotherapy. Eight patients had recurrence during glucocorticoid reduction, 6 of them were treated with additional second-line immunosuppressive therapy, including cyclophosphamide (1 case) and mycophenolate mofetil (5 cases). The follow-up time of patients were 5-99 months. At the last follow-up, all patients were in remission, the pediatric cerebral performance category (PCPC) score was 1 (10 cases) and 2 (1 cases). Conclusions: MNOS mainly affects older children. In the period of acute episodes, convulsions and psychosis are common. The cranial MRI showed extensive brain involvement and mainly in the cortex. The recurrence rates of MNOS are relatively high, patients are sensitive to first-line immunotherapy. No significant neurological dysfunction was left in the remission stage.

[Clinical features of 19 children with Bickerstaff brainstem encephalitis].

Objective: To summarize the clinical features of Bickerstaff brainstem encephalitis (BBE) in children. Methods: In this retrospective study, data of 19 patients with BBE (11 males and 8 females) were collected from Department of Neurology, Beijing Children's Hospital from October 2015 to January 2018. The clinical features, treatment and prognosis were analyzed. Results: The onset age of BBE ranged from 1 year and 8 months to 12 years and 11 months. There were 18 cases with preceding infection. The most common infection was upper respiratory tract infection (9 cases), followed by simple fever (5 cases). The most common initial neurological symptoms were lethargy or disturbance of consciousness (8 cases), followed by limb weakness (5 cases). There were 6 cases of simple BBE and 13 cases of BBE overlapping Guillain-Barré syndrome (GBS). Besides the characteristic triad of altered mental status, ataxia, and ophthalmoplegia, there were other symptoms including convulsion (5 cases), diplopia (3 cases), nystagmus (7 cases), facial muscular weakness (7 cases),bulbar palsy (13 cases) and autonomic nerve symptoms (9 cases). Hypo or areflexia was seen in 16 cases. Positive Babinski's signs were seen in 8 cases. Hyponatremia was present in 10 cases in whom 4 showed severe hyponatremia. Albumin-cytological dissociation of cerebrospinal fluid was seen in 10 cases. The autoimmune antibodies were examined in all 19 patients. Anti-ganglioside antibodies including anti-GM1 IgG antibody was positive in 2 patients and one of whom was also found with positive anti-GD1b IgG antibody. Anti-GQ1b IgG antibody was present in 2 patients. Electromyography was performed in 14 cases and 8 cases, who were all BBE overlapping GBS, showed neurological damage. A total of 16 cases were monitored by video electroencephalography and 8 cases showed slow waves of background. In addition to, interictal focal discharge was detected in 2 cases. T2 fluid-attenuated inversion recovery (FLAIR) sequence abnormal signals were detected in 3 of 18 cases performed brain magnetic resonance imaging (MRI), and lesions involved with brainstem, basal ganglia, thalamus, cerebellum, corpus callosum and cerebral cortex. Lesions involved cervical and thoracic spinal cord were found in 1 out of 11 cases for whom spinal cord MRI was performed. All of the 4 cases who underwent enhanced MRI of spinal had partial nerve roots enhancement. All of the 19 patients received 1 to 2 courses of intravenous immunoglobulin therapy, and 2 cases also received plasma exchange. Fifteen cases received steroid therapy. The following-up period ranged from 3 months to 2.5 years. Two cases were lost to follow-up. Twelve cases achieved a full recovery within 3 months. Three cases recovered within 6 months. One case still had slight limb weakness and ataxia after 1 year and 8 months of follow-up, and another case had left autonomic nerve symptoms in the follow-up of 2 years and 3 months. Both of them were BBE overlapping GBS. Conclusions: Children's BBE is similar to that in adults, and is frequently found overlapped with GBS. Furthermore, it is sometimes accompanied by central nervous system demyelination disease. The antiganglioside antibodies are not often detectable. Immunoglobulin therapy could usually achieve good response. The prognosis of simple BBE is good in most situations. For BBE overlapping GBS, the more severe the limb weakness during the peak of disease is, the slower the recovery would be.

[Clinical and laboratory characteristics and genetic diagnosis of Kabuki syndrome].

Objective: To investigate the clinical features, laboratory characteristics and genetic diagnosis of Kabuki syndrome (KS). Methods: Between September 2014 and September 2016, seven children with clinically diagnosed KS from the neurology department, Beijing Children Hospital, Capital Medical University were included in this study. Three of them were male and 4 were female aged from 19 days to 6 years and 4 months with a median age of 3 years and 1 month. The clinical features, laboratory and imaging materials, gene tests were analyzed prospectively. Results: Clinical manifestation: cephalofacial anomaly: all seven cases had unusual facies presented as long palpebral fissures, eversion of the lateral third of lower eyelids, arched eyebrow with brow sparse, epicanthus, orbital hypertelorism, short columella with broad and depressed nasal tip; six cases presented with palatal arch deformity; four cases presented with ptosis; three cases presented with dental abnormalities and hearing impairment respectively; two cases presented with strabismus and earlap malformation respectively; one case presented with amblyopia. Six cases presented with skeletal anomalies. Six cases presented with dermatoglyphic anomalies. All cases presented with mild to moderate mental retardation. Three cases presented with short stature. Four cases presented with cardiac abnormalities. Three cases presented with epileptic seizures. Others: three cases presented with dystonia and neonatal hyperbilirubinemia respectively; two cases presented with feeding problem and hypoglycemia respectively; one case presented with micropenis and fetal finger pads respectively. All seven patients received magnetic resonance imaging (MRI) tests, and none demonstrated an abnormal finding. Five patients received electroencephalogram (EEG) tests, and three of them presented with seizures and EEG abnormalities. Five patients received genetic testing and all presented with KMT2D heterozygous mutations which were new mutations proved by parents validation (three cases were nonsense mutations, one was frameshift mutation, one was missense mutation). All patients received rehabilitation training and symptomatic treatments. Three patients presented with epileptic seizures received antiepileptic therapy. At a median follow-up of 11 months (from 4 months to 2 years), one patient died, one lost to follow-up and five had improved intellectual and physical development. Epileptic seizures were controlled or reduced significantly in three patients presented with epileptic seizures. Conclusions: KS is a multisystem disease with complicated manifestations, which needs a combination of various diagnosis and treatments. Genetic testing can help determine the diagnosis. Unusual facies and mental retardation are the main clinical features and diagnostic clue. It is important to improve prognosis through increasing the knowledge of KS, early diagnosis, and treatment.