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 summarize the clinical characteristics of SYNGAP1-related epilepsy in children.Methods:Data of 13 patients with SYNGAP1 gene variants diagnosed with epilepsy at Department of Neurology, Beijing Children's Hospital were collected retrospectively from March 2017 to October 2020 and the patients were followed up. The clinical features, electroencephalogram(EEG), brain imaging, gene results and treatment were summarized.Results:Twelve patients were followed up successfully among the 13 patients with SYNGAP1 variants. The last follow-up age was 5 years and 7 months (3 years and 1 month to 9 years).The onset age of seizures was 2 years (4 months to 3 years). Seizure types included eyelid myoclonia with or without absence (9 cases), myoclonic seizure (5 cases), atypical absence (4 cases), suspicious atonic seizures(4 cases),unclassified fall attack (6 cases), and the frequency of seizures varied from several times to more than 100 times per day. Four cases had the mimic phenotype of myoclonic astatic epilepsy. The seizures of 10 cases could be triggered by eating (5 cases), emotion (5 cases), fever (3 cases), voice (2 cases), fatigue (2 cases), etc. Electroencephalography (10 cases) showed interictal generalized or focal epileptiform discharges (9 cases), and atypical aphasia (4 cases), myoclonic seizure (2 cases) and eyelid myoclonic seizure (1 case) were monitored. Of the 12 cases, 9 were added with valproate, all of which were effective (the frequency of seizures reduced>50%). Five cases received combined levetiracetam, in 3 the treatments were effective. To last follow-up, 3 cases were seizure free from 6 months to 1 year and 1 month, but the remaining 7 cases still had seizures, one or several times per day. All 13 cases had developmental retardation (speech ability impaired mostly), 2 cases were severe, 10 cases were moderate, 1 case was mild. The SYNGAP1 gene variants of 13 patients were all de novo, including 12 variants. Among them, 4 were frameshift variants, 4 were nonsense variants, 2 were missense variants and 2 were splice site variants.Conclusions:Patients with SYNGAP1-related epilepsy have an early onset age and many seizure types. The main seizure type is eyelid myoclonia with or without absence, and other seizure types include myoclonic seizure, atypical absence, unclassified fall attack, etc. Valproate is effective in most patients, but seizures in some patients might be intractable. Most patients have developmental delay (mainly moderate and severe), speech ability impaired mostly.

Objective:To summarize the clinical data of patients with acute pandysautonomia (APD) and discuss the treatment and prognosis of them.Methods:A total of 13 patients with APD in the Department of Neurology, Beijing Children′s Hospital, Capital Medical University, from January 2010 to December 2019, were investigated retrospectively.The general data, clinical symptoms, autonomic nerve examination and function test, laboratory examination, treatment and follow-up were collected and analyzed.Results:There were 4 males and 9 females in 13 patients with APD, with an average age was 8 years and 5 months (3 years and 8 months to 12 years and 5 months ). The average course of disease was 94.5 d (14-410 d). The common initial symptoms were gastrointestinal motility disorder (11 cases), dysuria (3 cases), and upright syncope/vertigo (3 cases). During the course of the disease, all the patients manifested with gastrointestinal motility disfunction and dyshidrosis, glands involvement and orthostatic hypotension in 12 cases, abnormal pupil in 9 case and urinary retention in 7 case.Other symptoms included fatigue in 9 cases, emotional disorder in 4 cases, limb weakness in 2 cases, and sensory disturbance in 2 cases.All the patients were treated with intravenous immunoglobulin (IVIG), and 3 cases combined with glucocorticoid.Six patients with severe gastrointestinal symptoms were treated with intravenous nutrition; 4 patients were fed with jejunum, 3 cases of whom returned to normal diet within 1-12 months, and 1 patient was followed up for 5 years and 2 months.Hyponatremia was found in 7 cases, which recovered in 2-30 d. Nine cases were followed up for 1 month to 9 years.Seven cases were normal in daily work and study, with satisfactory nutritional status, stable mood and no relapse.Conclusions:The clinical manifestations of APD are varied.The initial symptoms are gastrointestinal motility disorders, orthostatic hypotension, urinary retention and hyponatremia.Individualized multi-disciplinary comprehensive management for symptoms, especially the comprehensive treatment of gastrointestinal motility disorders, management of postural hypotension, and the urinary system diagnosis and individualized treatment of can shorten the length of hospital stay and improve the prognosis effectively.

Objective:To investigate the clinical and laboratory characteristics of subacute sclerosing panencephalitis (SSPE).Methods:The clinical, laboratory and electroencephalogram (EEG) data of eight patients with SSPE who admitted to the Department of Neurology, Beijing Children's Hospital, Capital Medical University, from May 2014 to February 2019 were retrospectively analyzed and followed up.Results:Four of the patients were male and four were female, who aged from two years and seven months to 13 years and five months with a median onset age of five years and six months. All of the eight cases had disease onset with progressive mental and physical regression, then developed periodic myoclonic seizures at the course of 11 days to 11 months. Video EEG examinations showed persistent generalized periodic complex waves with long interval (3-20 s). The IgG titers of measles virus in blood and cerebrospinal fluid of all cases were significantly increased. There was no significant abnormality in blood/urine metabolism screening nor head magnetic resonance imaging for the first time. Five cases performed head magnetic resonance imaging again, in which two cases with deepening hemispheric sulcus, two cases with cerebral white matter signal abnormalities. Antiepileptic drugs, gamma globulin, adrenocortical hormone and antiviral drugs were used after diagnosis though all were ineffective. All patients presented progressive deterioration. During the follow-up period of three months to two years and seven months, four patients died, of which three patients died at the time of five months, one year and two months, two years and six months after onset respectively, and the other one was unknown.Conclusions:The diagnostic clues of SSPE are progressive mental and physical regression, recurrent myoclonic seizures during period Ⅱ, as well as the extensive periodic complex waves of EEG. It is necessary to detect measles virus IgG antibody in blood and cerebrospinal fluid to make a definite diagnosis. There is no specific treatment for SSPE and its prognosis is very poor.

Objective: To explore the clinical characteristics and genotyping results of childhood-onset myoclonus dystonia syndrome caused by SGCE variants. Methods: The clinical data of 9 children with SGCE-related myoclonus dystonia syndrome admitted at either the Department of Neurology, Beijing Children′s Hospital, Capital Medical University or the Department of Pediatrics, Peking University First Hospital from May 2018 to October 2019 were collected and the patients were followed up. The definite diagnosis was made on the basis of whole exome sequencing and multiple ligation-dependent probe amplification. The clinical features and gene test results were analyzed retrospectively. Results: Data of 9 patients (4 boys and 5 girls) diagnosed as myoclonus dystonia syndrome caused by SGCE variants were collected. The onset age ranged from 1 year to 3 years and 2 months. The first symptom was myoclonus in 4 cases, while dystonia in the remaining 5 cases. In the course of the disease, 9 cases had myoclonus and 8 had dystonia. Myoclonic jerks were characterized by involuntary jerks in both upper limbs in 8 patients. Six patients had involuntary jerks of lower limbs, resulting in gait instability or even falling. The myoclonus was exacerbated during the fine motor activities, emotional stress or fatigue. Dystonia was characterized by abnormal gait, including 5 cases with right leg dystonia, and 3 cases with the left leg dystonia. Three probands had a positive family history. Intellectual development was normal in all cases. There was no obvious abnormality in video-electroencephalogram (EEG) during both ictal and interictal periods. Electromyography (EMG) and brain magnetic resonance imaging (MRI) of 9 patients were normal. Nine patients carried SGCE gene variants, including 3 frame shift variants, 2 nonsense variants, 2 missense variants, 1 fragment deletion variant and 1 splice site variant. Seven variants were inherited paternally, and 2 variants were de novo. Madopar was used in 8 patients, and nitrazepam in 4 patients, leading to the decrease in the myoclonus jerks and improvement of gait in 6 and 2 patients, respectively. Conclusions SGCE gene variants can cause myoclonus dystonia syndrome. The onset of the disease may occur at infancy or preschool age, with either myoclonic jerks or dystonia as the initial symptom. Non-epileptic myoclonus is the prominent symptom, with upper limb mainly involved. Most of the patients have the accompanying symptoms of dystonia, and some of them may have spontaneous symptom relief. SGCE gene is imprinted maternally, and the inherited variants of SGCE are paternal in origin.

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 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 characterize fever-induced paroxysmal weakness and encephalopathy (FIPWE) caused by ATP1A3 gene pathogenic variant. Methods: Phenotypic and genotypic characteristics of 4 FIPWE patients (3 boys and 1 girl), who were ascertained from October 2016 to March 2018 in Beijing Children's Hospital due to ATP1A3 heterozygous variants, were retrospectively analyzed. The whole exsome sequencing was used for genetic testing. Results: The onset ages of 4 patients were 2 years and 9 months, 2 years and 4 months, 8 months, 2 years and 5 months respectively. The episode ranged from 1 to 3 times, and at 3 months to 2 years and 10 months intervals. All 4 patients had symptoms of limb weakness and encephalopathy, accompanied with mild to severe ataxia or athetosis. The tendon reflex was absent in all patients, and the Babinski's sign was positive. Three patients had dysphagia and 3 patients had slurred speech. Three patients had abnormal eye movements, including strabismus and opsoclonus. None of the 4 patients exhibited visual impairment, auditory impairment or talipes cavus. The duration of acute phase ranged from 1 week to 3 months. In 3 relapsing patients, symptoms became progressively worse, with relapses occurring frequently and recovery being more difficult, and various sequelae were found after the last relapse. All patients carried heterozygous variant in ATP1A3 gene. The missense variants result in the substitution of an arginine residue at position 756. Three variants were identified, including C. 2267G > T (p. R756L) (1 case), C. 2266C > T (p. R756C) (2 cases), and C. 2267G > A (p. R756H) (1 case). Three were de novo and one inherited from his father, but the grandparents did not carry the variant. All variants were reported as pathogenic. Conclusions FIPWE is one of new clinical phenotypes of ATP1A3 spectrum disease and most cases are sporadic. The missense variants result in the substitution of an arginine residue at position 756. This report provided insights into the phenotype-genotype association in patients with FIPWE caused by pathogenic variants of ATP1A3.

Objective: To describe the clinical manifestations of central nerve system inflammatory demyelinating disease associated with anti-myelin oligodendrocyte glycoprotein antibody (MOG-IDD) in children, and to explore the clinical characteristics of the children. Methods: The clinical and laboratory characteristics of the patients diagnosed in Beijing Children′s Hospital, Capital Medical University, from October 2016 to August 2018 were described, and the clinical data of the patients with unipolar and recurrent diseases were compared. Results: A total of 50 patients were included, among whom the ratio of male to female was 24:26, and the average age of onset was (6.7±3.1) years old (0.4-12.6 years old). There was no significant difference in the age of onset between boys and girls(t=0.712, P=0.480). The main symptoms included fever (31/50 cases), encephalopathy (26/50 cases) and optic neuritis (22/50 cases), etc.In the last follow-up, 26 patients (52.0%) had a monophasic course and 24 patients (48.0%) had a recurrent course.There were age differences in encephalopathy and ataxia in the first episode of [(5.7±2.8) years old vs.(8.1±3.0) years old, (5.0±2.5) years old vs. (7.7±3.0) years old](t=2.746, P=0.009; t=2.837, P=0.007). The average number of recurrence was (2.1±1.4) times (1-7 times), in which 17 cases (70.8%) of recurrence presented within 12 months and 20 cases (83.3%) of recurrence presented within 24 months after onset.Convulsion incidences of recurrent cases were 10 cases and 13 cases respectively in the first episode and recurrent courses, which were significantly higher than those of monophasic cases (4 cases, 4 cases)(χ²=7.912, P=0.005; χ²=8.365, P=0.004). All patients were sensitive to first-line immunotherapy.Seven patients with recu-rrence were treated with mycophenolatemofetil, and 17 patients with repeated first-line therapy.In the last follow-up, all patients were in remission and 2 patients had mild neurological dysfunction. Conclusions MOG-IDD can occur in childhood.Encephalopathy and optic neuritis are the most common symptoms.Encephalopathy and ataxia are more common in young children.Convulsions may indicate the course of recurrence.

Objective To characterize fever‐induced paroxysmal weakness and encephalopathy (FIPWE) caused by ATP1A3 gene pathogenic variant. Methods Phenotypic and genotypic characteristics of 4 FIPWE patients(3 boys and 1 girl), who were ascertained from October 2016 to March 2018 in Beijing Children′s Hospital due to ATP1A3 heterozygous variants, were retrospectively analyzed. The whole exsome sequencing was used for genetic testing. Results The onset ages of 4 patients were 2 years and 9 months, 2 years and 4 months, 8 months, 2 years and 5 months respectively. The episode ranged from 1 to 3 times, and at 3 months to 2 years and 10 months intervals. All 4 patients had symptoms of limb weakness and encephalopathy, accompanied with mild to severe ataxia or athetosis. The tendon reflex was absent in all patients, and the Babinski′s sign was positive. Three patients had dysphagia and 3 patients had slurred speech. Three patients had abnormal eye movements, including strabismus and opsoclonus. None of the 4 patients exhibited visual impairment, auditory impairment or talipes cavus. The duration of acute phase ranged from 1 week to 3 months. In 3 relapsing patients, symptoms became progressively worse, with relapses occurring frequently and recovery being more difficult, and various sequelae were found after the last relapse. All patients carried heterozygous variant in ATP1A3 gene. The missense variants result in the substitution of an arginine residue at position 756. Three variants were identified, including C. 2267G>T (p. R756L) (1 case), C. 2266C>T (p. R756C) (2 cases), and C. 2267G>A (p. R756H) (1 case). Three were de novo and one inherited from his father, but the grandparents did not carry the variant. All variants were reported as pathogenic. Conclusions FIPWE is one of new clinical phenotypes of ATP1A3 spectrum disease and most cases are sporadic. The missense variants result in the substitution of an arginine residue at position 756. This report provided insights into the phenotype‐genotype association in patients with FIPWE caused by pathogenic variants of ATP1A3.