Objective:To summarize the clinical characteristics and genetic features of tyrosine hydroxylase deficiency(THD) caused by TH gene variants for the improvement of the understanding of the disease. Methods:The clinical and genetic data of 33 children with THD caused by TH gene variants were diagnosed in the Department of Neurology of Beijing Children′s Hospital, Capital Medical University from May 2011 to January 2020 and their data were retrospectively collected and analyzed. Results:There were 19 females and 14 males.The age at onset was ranged from 0 to 6.3 years.13 patients developed diseases, accompanied with fever after infection, and 1 patient suffered from hypoxia, 19 patients suffered from no predisposing factors.There were 7 mild TH-deficient dopa-responsive dystonia cases, 16 severe TH-deficient infantile parkinsonism with motor delay cases and 10 very severe TH-deficient progressive infantile encephalopathy cases.Clinical symptoms were fluctuating, including 26 cases of diurnal fluctuation, 22 cases of infection aggravation, and 30 cases of fatigue aggravation.The initial symptoms included tiptoeing and numbness in the limbs(7 cases), motor development retardation or degression (26 cases), fremitus (8 cases), ptosis (2 cases), and status dystonicus (3 cases). Other clinical features had hypermyotonia (23 cases), hypomyotonia (27 cases), decreased movement (27 cases), decreased facial expression (24 cases), fremitus (18 cases), tiptoeing (20 cases), talipes equinovarus (7 cases), ptosis (8 cases), oculogyric crisis (10 cases), salivation (21 cases), dysphagia (12 cases), dysarthria (16 cases), dyspnea (3 cases), increased sleep (10 cases), decreased sleep (5 cases), irritable mood (15 cases), apathetic mood (2 cases), profuse sweating (8 cases), and status dystonicus (6 cases). A total of 6 patients′ right limbs were more severe, and 14 patients′ lower limbs were more severe.Eight patients had family history, and Levodopa treatment was effective for all patients.Ten patients suffered side effects, including dyskinesia and irritability.Four patients were lost follow-up, and 29 patients were followed up between 0.8 and 13.2 years old until Ja-nuary 2020.Totally, 22 patients almost had no such symptoms.Twenty-five TH gene pathogenic variants were discovered in 33 patients.There were 13 novel variants (c.1160T>C, c.1303T>C, c.887G>A, c.1084G>A, c.1097A>T, c.734G>T, c.907C>G, c.588G>T, c.992T>G, c.755G>A, c.184-6C>T, c.1510C>T, c.910G>A) and 2 patients had c. 910G>A variant.Meanwhile, there were 5 hot variants [c.698G>A(13 cases), c.457C>T(9 cases), c.739G>A(6 cases), c.1481C>T(4 cases), c.694C>T(3 cases)]. c.910G>A(2 cases) may be the foun-der variant of Chinese population. Conclusions:THD caused by TH gene variant mostly onsets from infant, with complex clinical features.Most of these patients were severe, and only a few were very severe and mild.Very severe and mild symptoms were easily misdiagnosed.Levodopa treatment was obviously effective.A possible founder variant of Chinese population (c.910G>A) was found.c.698G>A and c. 457C>T mutations mainly appeared in patients with severe and extremely severe THD, while c. 739G>A mainly appeared in patients with mild THD.

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.

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.

Objective:To analyze the clinical and imaging features of influenza associated encephalopathy(IAE) in children, thus contributing to enhance the efficacy of early identification, timely treatment and prognosis.Methods:Clinical data, laboratory examination, imaging data, treatment and outcomes of 40 children with IAE diagnosed and treated in the Beijing Children′s Hospital, Capital Medical University from December 2016 to January 2020 were retrospectively analyzed.Clinical features were summarized and they were further classified according to clinical imaging features.The prognosis was compared and analyzed.Results:A total of 20 boys and 20 girls were recruited, with the age of attending hospital at (4.0±2.3) years (median, 3.2 years). There were 28 children with influenza A and 12 with influenza B. All children initially had fever, and the interval between fever and symptoms of neurological onset was 24 hours (0-120 hours). The most-common symptom of neurological onset was seizures(32 cases), among which 17 patients showed continuous seizures.All children presented encephalopathy at varying degrees, including 33 cases in coma and 7 in drowsiness or cognitive decline.Thirty cases developed central respiratory failure and received mechanical ventilation.Examination results showed 30 cases had elevated aspartate transaminase (AST), 18 cases had elevated alanine transaminase (ALT), 14 cases had elevated creatinine, 31 cases had elevated lactate dehydrogenase, 16 cases had elevated blood glucose and 1 case had significantly lowered blood glucose.Blood ammonia testing was performed in 38 children and 9 cases had elevated level.The whole exon sequencing in 6 cases showed de novo heterozygous mutation of the SCN1A gene in 1 case, and heterozygous mutation of the ATP1A2 gene inherited from the mother in another case.Lumbar puncture was performed in 35 cases, and all of them had a normal range of cerebrospinal fluid leukocyte counts, while 12 cases had elevated cerebrospinal fluid proteins.Abnormal image findings were examined in 33 cases and the acute necrotizing encephalopathy was the most common one (14 cases). All children received Peramivir or Oseltamivir after admission.A total of 28 cases were treated with glucocorticoids, and 29 cases were treated with immunoglobulin.Seventeen cases died, 9 cases had disability at varying degrees, and 14 cases recovered to the baseline.Patients were divided into good prognosis group and poor prognosis group.(1) Patients in good prognosis group presented significantly shorter interval between fever and first neurological symptoms[(22.7±12.2) h vs.(38.6± 30.9) h], higher Glasgow score on admission[(7.6±2.5) points vs.(4.5 ± 1.6) points], lower ALT [15.6 (9.0-1 631.5) U/L vs.140.2 (12.3-3 232.4) U/L] and lower AST [47.6 (25.4-1 721.3) U/L vs.251.8 (21.7-4 991.6) U/L] than those in poor prognosis group (all P<0.05). (2) Glucocorticoids were applied to 17 and 11 cases in good prognosis group and poor prognosis group, while immunoglobulins were applied to 17 and 12 cases, respectively ( P>0.05). (3) Patients were further classified into cytokine storm group, excitotoxicity group and unclassifiable group according to clinical imaging findings.The Glasgow score [ (4.6±1.7) points vs.(7.6±2.2) point vs.(7.3±2.8) points] and median modified Rankin Scale score (6.0 points vs.1.5 points vs.0) were significantly different among 3 groups (all P<0.01). Conclusions:Influenza associated encephalopathy is common in infants and young children.Fever, convulsions and rapidly progressing disturbance of consciousness are the most common clinical manifestations.Acute necrotizing encephalopathy is the most common subtype of clinical imaging syndrome.Acute onset and rapid progression predict the poor prognosis of influenza associated encephalopathy.

Objective:To investigate the clinical application of the new classification criteria in children with Miller Fisher syndrome (MFS), and to analyze clinical characteristics of different types of MFS.Methods:Clinical data of MFS patients hospitalized in the Department of Neurology, Beijing Children′s Hospital, Capital Medical University from January 2015 to December 2019 were collected and analyzed retrospectively, including demographic characteristics, clinical symptoms, neurological examination findings, laboratory examination data, diagnosis and treatment, and prognosis.The counting data was described by percentage, and the measurement data was described by median.Results:A total of 23 patients were included in the research, including 14 males and 9 females, with a median age of 4 years and 8 months.There were 3 cases of pure MFS; 5 cases of incomplete MFS, including 1 case of acute ptosis and 4 cases of acute ataxia neuropathy; 15 cases of overlapping syndrome, including 13 cases of MFS/Guillain Barre syndrome (GBS), 1 case of MFS/pharyngocervical brachial variant GBS(PCB GBS)and 1 case of MFS/GBS/Bickertaff brainstem encephalitis (BBE). In addition to Ⅲ, Ⅳ and Ⅵ cranial nerve palsy, 11 cases had the involvement of other cra-nial nerves, including 2 cases in pure MFS, 8 cases in MFS/GBS and 1 case in MFS/GBS/BBE.Autonomic nervous dysfunction occurred in 6 cases.Respiratory muscle paralysis occurred in 6 cases, including 5 cases in MFS/GBS and 1 case in MFS/GBS/BBE.Graded by the Hughes scoring system (HG score), 3 cases with pure MFS were graded 4 points; 1 case with acute ptosis was graded 0; 3 cases with acute ataxia neuropathy were graded 2 points, and the other one was graded 3 points; 1 case with MFS/PCB GBS was graded 3 points; 10 cases with MFS/GBS were graded 4 points, 1 case was graded 3 points, and the other 2 cases were graded 2 points; 1 case with MFS/GBS/BBE was graded 4 points.Twenty-two patients were treated with intravenous immunoglobulin.The HG of all patients at discharge decreased at varying degree, which was graded 0 at 6 months of follow-up.Conclusions:The clinical application of the new diagnostic classification method is helpful to the accurate diagnosis of different types of MFS.More than half of MFS cases will develop into the overlapping syndrome.The overlapping of MFS and GBS or BBE is prone to the involvement of cranial nerves except for the external ophthalmic muscles, autonomic nerve dysfunction and respiratory muscle paralysis.The disease course of MFS varies, and its diagnosis should be comprehensively made.All cases of MFS in this study have a satisfactory prognosis.

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.

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.

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.

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.