Leigh Syndrome in Childhood: Neurologic Progression and Functional Outcome

BACKGROUND AND PURPOSE: Few studies have analyzed the clinical course and functional outcome in Leigh syndrome (LS). The aim of this study was to determine the clinical, radiological, biochemical, and genetic features of patients with LS, and identify prognostic indicators of the disease progression and neurological outcome. METHODS: Thirty-nine patients who had been diagnosed with LS at the Seoul National University Children's Hospital were included. Their medical records, neuroimaging findings, and histological/biochemical findings of skeletal muscle specimens were reviewed. Targeted sequencing of mitochondrial DNA was performed based on mitochondrial respiratory chain (MRC) enzyme defects. RESULTS: Isolated complex I deficiency was the most frequently observed MRC defect (in 42% of 38 investigated patients). Mitochondrial DNA mutations were identified in 11 patients, of which 81.8% were MT-ND genes. The clinical outcome varied widely, from independent daily activity to severe disability. Poor functional outcomes and neurological deterioration were significantly associated with early onset (before an age of 1 year) and the presence of other lesions additional to basal ganglia involvement in the initial neuroimaging. CONCLUSIONS: The neurological severity and outcome of LS may vary widely and be better than those predicted based on previous studies. We suggest that age at onset and initial neuroimaging findings are prognostic indicators in LS.

Painful legs and moving toes syndrome in a 16-year-old girl / 소아과

Painful legs and moving toes (PLMT) syndrome is characterized by spontaneous movements of the digits and pain in one or both lower extremities. Of the reported cases, a majority of the patients was female, and the mean age of onset was 58 years. Only one pediatric case has been reported so far. Herein, we report the first adolescent case of PLMT in Korea. A 16-year-old girl complained of tingling pain in the left leg and involuntary movement of the ipsilateral great toe one month after a second untethering surgery. Three years ago, she had undergone untethering surgery to correct lipomeningomyelocele at the S2 level of the conus medullaris. At that time, she was diagnosed with polyradiculopathy at the left L5 level with axonal involvement. We diagnosed her with PLMT syndrome and prescribed gabapentin. Her symptoms diminished within a day. Complete relief from involuntary movement of the toe was achieved within four months. PLMT is a rare syndrome but it should be considered in the differential diagnosis of children and adolescents with limb pain and spontaneous movement in their toes.

Efficacy and Tolerability of Valproic Acid Once Daily Dosing for Juvenile Myoclonic Epilepsy / 대한소아신경학회지

PURPOSE: The purpose of this study was to evaluate the efficacy and tolerability of extended-release valproic acid once daily dosing in juvenile myoclonic epilepsy (JME). METHODS: Medical records of patients who received valproic acid monotherapy for the treatment of JME were retrospectively reviewed. Their clinical information regarding age, gender, seizure types, underlying neurologic status, dosing regimen, response to treatment, and adverse events related to valproic acid, were analyzed. Seizure control, compliance, and adverse events rates were compared between the group of once daily dosing and the group of twice daily dosing. RESULTS: Twenty one patients (11 boys and 10 girls) were included in the study. Twelve patients were taking valproic acid extended-release once daily and nine patients were taking twice a day. More than 50% decrease in myoclonic seizure was achieved in all the patients in both groups. Generalized tonic-clonic seizure was controlled in all the patients who were taking once daily while 3 patients (36%, 3/8 patients) in twice daily group had breakthrough generalized tonic clonic seizures during the 2 year period of treatment. However, there were no statistically significant differences in seizure control, compliance, and adverse event rates between the two groups. CONCLUSION: This study demonstrated that valproic acid extended-release once daily dosing was as effective and tolerable as twice daily in the treatment of JME. Once daily dosing of valproic acid would be convenient which improve patient compliance and consequently bring better outcome in treatment of JME.

Electroencephalographic Features of Rasmussen's Encephalitis by Stage / 대한소아신경학회지

PURPOSE: The purpose of this study was to describe the characteristic electroencephalographic features in Rasmussen's encephalitis by stage. METHODS: Patients diagnosed with Rasmussen's encephalitis at Seoul National University Children's Hospital were retrospectively assessed. We analyzed the background activities and epileptiform discharges from electroencephalography (EEG) findings to identify the characteristic EEG features by stage. RESULTS: Seven patients were included in the study. The mean age of first seizure onset was 6.7 years, and the mean duration of the prodromal phase was 21.4 months. During disease course, background activities, such as slow waves, were more prominent and diffuse, and contralateral slow waves were observed. In most patients, focal epileptiform discharges were observed during all stages without change. CONCLUSION: As Rasmussen's encephalitis progresses, background abnormalities in the affected hemisphere increased, and contralateral slow waves occurred. However, characteristic EEG findings that were distinguishable at each stage were not observed.

Effectiveness and Tolerability of Fosphenytoin for Pediatric Status Epilepticus / 대한소아신경학회지

PURPOSE: The study was aimed to investigate the effectiveness and tolerability of intravenous fosphenytoin (fPHT) in the treatment of pediatric status epilepticus (SE). METHODS: Medical-records of patients who received intravenous (IV) fPHT for the treatment of SE were retrospectively reviewed and their clinical data were analyzed regarding age, gender, seizure types, underlying neurologic status, use of other anticonvulsants, loading dose, response and adverse events of IV fPHT. RESULTS: Twenty patients (12 boys and 8 girls) were included in the study. The mean age at administration of IV fPHT was 3.98 years (range 0-18.6 years). Of the 20 patients, 15 patients had no underlying neurological conditions, but five patients were on anticonvulsants. IV fPHT terminated the seizures in 15 of the 20 patients (75%). No adverse events occurred during or after the infusions. CONCLUSION: This study demonstrated that IV fPHT was as effective as phenytoin and was well-tolerated in the treatment of pediatric SE. IV fPHT can be considered as a substitute for phenytoin in the management of pediatric SE.

Clinical Characteristics and Efficacy of Prophylactic Treatment of Pediatric Chronic Daily Headache / 대한소아신경학회지

PURPOSE: The purpose of this study was to evaluate the clinical characteristics and efficacy of prophylactic treatment of pediatric chronic daily headache (CDH). METHODS: A retrospective medical-record review of patients who underwent the prophylaxis after a diagnosis of CDH was performed. Response to treatment was assessed by the total number of headache days/month. More than 50% reduction of headache frequency was classified as responders. RESULTS: Eighty patients with the diagnosis of CDH were included in the study. CDH was more prevalent in girls than in boys. It was classified into chronic migraine (81.2%), chronic tension-type headache (15.0%), or new-onset persistent daily headache (3.7%). None of the patient fulfilled the diagnostic criteria of hemicrania continua. The mean age of the patients was 11.8+/-1.2 years. The mean number of monthly headache episodes before treatment was 25.5+/-4.4. After prophylactic treatment, headache episodes were reduced to 8.7+/-9.5 episodes per month. The responder rate of prophylactic treatment was 70.2% (55/80 patients) for either topiramate or flunarizine. CONCLUSION: In our study, the most common type of CDH was chronic migraine. All patients with CDH had frequent, long lasting migraine attacks. This study also suggests that prophylactic treatment is effective in the treatment of pediatric CDH.

A Case of Japanese Encephalitis Presenting with Fever and Seizure in a 7-month old Infant / 대한소아신경학회지

Japanese encephalitis is one of the leading causes of acute encephalitis in Asia. But in Korea, the number of Japanese encephalitis cases has dropped considerably due to mass vaccination and vector control. Especially, there were no case reports under the age of 9 years during the last ten years. We will describe a case of a previously healthy 7-month old boy who presented with fever and seizure. The patient was diagnosed with Japanese encephalitis, based on the cerebrospinal fluid and serum antibody analyses for the Japanese encephalitis virus. Typical brain magnetic resonance image findings of Japanese encephalitis were observed. The patient received extensive conservative treatment including high dose intravenous corticosteroid treatment and immunoglobulin. In spite of severe hemodynamic instability, the patient survived, and he is currently in a vegetative state with respiratory assist by a home ventilator. Although the incidence of Japanese encephalitis dropped dramatically in Korea, pediatricians should always consider the diagnosis as one of the possibilities for patients with encephalitis, especially if the patient is not immunized for JEV. Since there is no specific treatment for JEV, timely and comprehensive conservative care is critical to reduce the mortality and morbidity.

A Neonatal Form of Alexander Disease Presented with Intractable Seizures and Obstructive Hydrocephalus

Alexander disease is a rare degenerative leukodystrophy caused by dominant mutations in glial fibrillary acidic protein (GFAP). The neonatal form of Alexander disease may manifest as frequent and intractable seizures or obstructive hydrocephalus, with rapid progression leading to severe disability or death within two years. We report a case of a 50-day-old male who presented with intractable seizures and obstructive hydrocephalus. His initial magnetic resonance imaging (MRI) suggested a tumor-like lesion in the tectal area causing obstructive hydrocephalus. Despite endoscopic third ventriculostomy and multiple administrations of antiepileptic drugs, the patient experienced intractable seizures with rapid deterioration of his clinical status. After reviewing serial brain MRI scans, Alexander disease was suspected. Subsequently, we confirmed the de novo missense mutation in GFAP (c.1096T>C, Y366H). Although the onset was slightly delayed from the neonatal period (50 days old), we concluded that the overall clinical features were consistent with the neonatal form of Alexander disease. Furthermore, we also suspected that a Y366 residue might be closely linked to the neonatal form of Alexander disease based on a literature review.

Clinical Characteristics of Post-traumatic Seizures in Children / 대한소아신경학회지

PURPOSE: Post-traumatic seizures (PTS) are well-recognized complications from head injuries and children are particularly more vulnerable to them. The aim of this study was to investigate the clinical characteristics of PTS in children and the findings of several diagnostic tools and to determine the role of prophylactic anticonvulsants. METHODS: We retrospectively reviewed the medical records of patient under 18 years of age who presented with seizures after traumatic brain injuries. Data analyzed included patient's demographics, clinical presentations, radiological and electroencephalographic findings, management and outcomes. RESULTS: Thirty one patients with PTS were included in the study and consisted of 13 males and 18 females. A mean age of the accident was 3.2 years (4 months-6.8 years) and a mean duration of follow-up was 26.0 months (12 months-54 months). Twenty one patients (67.7%) developed seizures within 24 hours after injury. Focal radiological findings were observed in 83.8% and described as subdural or epidural hematoma (25.8%), intraparenchymal hemorrhage (19.3%) and intracerebral parenchymal lesions (51.6%). Electroecephalographic findings included background abnormalities in 32.2% and interictal epileptiform discharges in 45.1%. All patients were treated with anticonvulsants for a certain period of time and a mean duration of treatment was 12.5 weeks (4-40 weeks). Eight patients (25.8%) developed subsequent seizures during follow-up period and 2 patients (6.5%) were diagnosed afterward with post-traumatic epilepsy. CONCLUSION: PTS generally take a benign clinical course, but subsequent seizures including epileptic seizures can occur in minor proportion. In these cases, radiological and electroencephalographic findings are helpful in prediction of clinical course of PTS.

Magnetoencephalography in Pediatric Lesional Epilepsy Surgery

This study was performed to assess the usefulness of magnetoencephalography (MEG) as a presurgical evaluation modality in Korean pediatric patients with lesional localization-related epilepsy. The medical records and MEG findings of 13 pediatric patients (6 boys and 7 girls) with localization-related epilepsy, who underwent epilepsy surgery at Seoul National University Children's Hospital, were retrospectively reviewed. The hemispheric concordance rate was 100% (13/13 patients). The lobar or regional concordance rate was 77% (10/13 patients). In most cases, the MEG spike sources were clustered in the proximity of the lesion, either at one side of the margin (nine patients) or around the lesion (one patient); clustered spike sources were distant from the lesion in one patient. Among the patients with clustered spike sources near the lesion, further extensions (three patients) and distal scatters (three patients) were also observed. MEG spike sources were well lateralized and localized even in two patients without focal epileptiform discharges in the interictal scalp electroencephalography. Ten patients (77%) achieved Engel class I postsurgical seizure outcome. It is suggested that MEG is a safe and useful presurgical evaluation modality in pediatric patients with lesion localization-related epilepsy.

Efficacy and Tolerability of Rufinamide for Intractable Generalized Epilepsies / 대한소아신경학회지

PURPOSE: The purpose of the study was to evaluate the efficacy and safety of rufinamide for intractable generalized epilepsies. METHODS: Eighteen patients with intractable generalized epilepsies were included in the study. Their medical records were retrospectively reviewed. Rufinamide was administered as an add-on treatment for intractable epilepsies. The initial administered dose was 10 mg/kg/day, which was subsequently titrated up to 30-50 mg/kg/day. The effectiveness was assessed by comparing the frequency of seizures after the treatment. The difference in number of seizures during 4 weeks was compared before and after reaching the final dose. RESULTS: The study population consisted of 13 males and 5 females (mean age 13.6+/-6.2 years, range 3.3-29.2 years). The responder rate (> or =50% in seizure frequency) was 39% and the seizure free rate was 11%. Retention rate was 44% and the reasons for withdrawal was adverse events (6/18 patients, 33%), aggravation of seizures (4/18 patients, 22%), and ineffectiveness (2/18 patients, 11%). Adverse events included hyperactivity, somnolence, ataxia and polyhidrosis. Adverse events and seizure aggravation occurred even at the starting dose of rufinamide treatment. CONCLUSION: Rufinamide can be used as an efficacious and safe adjunctive anticonvulsant for patients with intractable generalized epilepsy.

A case of Becker muscular dystrophy with early manifestation of cardiomyopathy / 소아과

An 18-year-old boy was admitted with chest discomfort, nausea, and dyspnea at rest. At the age of 3 years, he underwent muscle biopsy and dystrophin gene analysis owing to an enlarged calf muscle and elevated serum kinase level (6,378 U/L) without overt weakness; based on the results, Becker muscular dystrophy (BMD) was diagnosed. The dystrophin gene showed deletion of exons 45 to 49. He remained ambulant and could step upstairs without significant difficulties. A chest roentgenogram showed cardiomegaly (cardiothoracic ratio, 54%), and his electrocardiogram (ECG) showed abnormal ST-T wave, biatrial enlargement, and left ventricular hypertrophy. The 2-dimensional and M-mode ECGs showed a severely dilated left ventricular cavity with diffuse hypokinesis. The systolic indices were reduced, including fractional shortening (9%) and ejection fraction (19%). Despite receiving intensive medical treatment, he died from congestive heart failure 5 months after the initial cardiac symptoms. We report a case of BMD with early-onset dilated cardiomyopathy associated with deletion of exons 45 to 49. Early cardiomyopathy can occur in BMD patients with certain genotypes; therefore, careful follow-up is required even in patients with mild phenotypes of BMD.

A case of isodicentric chromosome 15 presented with epilepsy and developmental delay / 소아과

We report a case of isodicentric chromosome 15 (idic(15) chromosome), the presence of which resulted in uncontrolled seizures, including epileptic spasms, tonic seizures, and global developmental delay. A 10-month-old female infant was referred to our pediatric neurology clinic because of uncontrolled seizures and global developmental delay. She had generalized tonic-clonic seizures since 7 months of age. At referral, she could not control her head and presented with generalized hypotonia. Her brain magnetic resonance imaging scans and metabolic evaluation results were normal. Routine karyotyping indicated the presence of a supernumerary marker chromosome of unknown origin (47, XX +mar). An array-comparative genomic hybridization (CGH) analysis revealed amplification from 15q11.1 to 15q13.1. Subsequent fluorescence in situ hybridization analysis confirmed a idic(15) chromosome. Array-CGH analysis has the advantage in determining the unknown origin of a supernumerary marker chromosome, and could be a useful method for the genetic diagnosis of epilepsy syndromes associated with various chromosomal aberrations.

Neurologic Complications of Bacterial Meningitis in Children / 대한소아신경학회지

PURPOSE: This study was performed to investigate clinical findings of acute neurologic complications and risk factors for chronic neurologic complications of bacterial meningitis in children. METHODS: Pediatric patients with community acquired bacterial meningitis diagnosed at Seoul National University Children's Hospital and Bundang Seoul National University Hospital were included. We investigated the relative frequency of neurologic complications and distribution of causative organisms. Chronic neurologic complication was defined as persistent neurologic deficit including recurrent seizures 6 months from the diagnosis. Multiple logistic regression analysis was used to identify risk factors for epilepsy and motor deficits, which were the most frequently reported chronic neurologic complications. RESULTS: A total of 90 cases were included in the study. Thirteen cases with less than 6 months follow-up duration were excluded from the analysis of risk factors for chronic neurologic complications. The mean age at diagnosis was 15.6 months. Streptococcus agalactiae was the most common pathogen accounting for 27 cases, followed by Streptococcus pneumoniae (19 cases), Hemophilus influenzae type b (13 cases), and Neisseria meningitidis (12 cases). Acute neurologic complications were found in 28 cases (31%): cerebral infarction in 16 cases, subdural effusion in 15 cases, and hydrocephalus in 9 cases. Chronic neurologic complications were found in 41 (53%) cases: epilepsy in 28 cases, motor deficit in 16 cases, hearing loss in 6 cases, and cognitive impairment in 4 cases. Cerebral infarction and S. pneumoniae infection were identified as risk factors for epilepsy. Cerebral infarction was a unique risk factor for motor deficit. CONCLUSION: Cerebral infarction is the important risk factor for the development of chronic neurologic complications including epilepsy and motor deficit in pediatric patients with bacterial meningitis.

Neurologic Manifestations and Prognosis in Hemophagocytic Lymphohistiocytosis / 대한소아신경학회지

PURPOSE: Hemophagocytic lymphohistiocytosis (HLH) presenting with neurologic manifestationhas a poor prognosis due to delayed diagnosis and treatment. We investigated the time between onset of symptoms and diagnosis of HLH and clinical findings and outcome in patients with HLH presenting with neurologic manifestation. METHODS: We retrospectively assessed 24 patients with HLH in Seoul National University Children's Hospital from January 2002 to December 2010. Sex, age on diagnosis, symptoms, laboratory findings, time between onset of symptoms and diagnosis of HLH, cerebral spinal fluid (CSF) findings and brain magnetic resonance imaging (MRI) findings were reviewed. RESULTS: At diagnosis, 7 children (29.2%) had neurologic symptoms, including seizure (n=6) and right side weakness (n=1). Time to diagnosis from onset of symptoms ranged between 7 and 385 days in patients with neurologic symptoms and between 2 and 87 days in patients without neurologic symptoms. Five patients had brain MRI abnormalities; radiologic findings were multiple high signal intensity lesions on T2-weighted image (n=3), focal high signal intensity lesion followed by severe cerebral edema (n=1), and diffuse cerebral atrophy (n=1).Of these 7 patients, 4 died, 1 underwent stem cell transplantation and was followed, 1 was followed after completion of therapy without neurologic sequelae, and 1 is still under treatment and has mild neurologic sequelae. CONCLUSION: HLH presenting with neurologic manifestation is difficult to distinguish from other diseases because of nonspecific symptoms and imaging findings. However, HLH is treatable with chemotherapy and stem cell transplantation, so it is important to consider HLH in a patient with neurologic disease that is unresponsive to treatment and accompanies systemic symptoms.

Prognostic Indicators of Gross Motor Developmental Outcomes in Preterm Infants with Cerebral Insults as Detected by Neuroimaging / 대한소아신경학회지

PURPOSE: To examine the developmental outcome of preterm infants with cerebral insults and to evaluate the prognostic indicators for gross motor development. METHODS: Forty-eight preterm infants less than 37 weeks of gestation, who had been born at Seoul National University Bundang Hospital between March, 2004 and September, 2008 where the subjects of this. The infants' charts were reviewed to obtain data, including gestational age, birth weight, gender, 1/5 minute Apgar scores, neuroimaging findings, and others. RESULTS: Of the 48 patients, 29 infants (60.4%) were put into a normal developmental group and 19 (39.6%) were put into developmental delay group. Univariate analysis of the two groups showed that P values less than 0.05 were observed with respect to gestational age, premature rupture of membrane (PROM), respiratory distress syndrome, bronchopulmonary dysplasia, and patent ductus arteriosus. PROM and antenatal steroid showed statistically significant differences on a multivariate analysis. The same analysis method was applied to preterm infants less than a corrected age of 32 weeks. Multivariate analysis suggested that PROM showed statistically significant differences. Also, 48 patients were analyzed with respect to neuroimage finding. Twenty-five infants (52.1%) were assigned to a germinal matrix hemorrhage (GMH) group and 23 infants (47.9%) were allocated to a non-GMH group. Cesarean section delivery showed statistically significant difference according to univariate analysis. CONCLUSION: In preterm infants with cerebral insults, PROM and antenatal steroids were independent risk factors for impaired gross motor development.

A case of Rubinstein-Taybi Syndrome with a CREBbinding protein gene mutation / 소아과

Rubinstein-Taybi syndrome (RTS) is a congenital disorder characterized by typical facial features, broad thumbs and toes, with mental retardation. Additionally, tumors, keloids and various congenital anomalies including congenital heart defects have been reported in RTS patients. In about 50% of the patients, mutations in the CREB binding protein (CREBBP) have been found, which are understood to be associated with cell growth and proliferation. Here, we describe a typical RTS patient with Arnold-Chiari malformation. A mutation in the CREBBP gene, c.4944_4945insC, was identified by mutational analysis.

A Case of Pediatric Nephrolithiasis Associated with Topiramate Treatment / 대한소아신경학회지

Topiramate is an antiepileptic drug widely used to treat various seizures, mood disorders and migraine based on its various pharmacological mechanisms. Even though nephrolithiasis is listed as one of its side effects, there have been no cases reporting nephrolithiasis caused by use of topiramate on Korean pediatric patients. Since the use of topiramate is increasing in many patients, the possibility of nephrolithiasis after the treatment needs to be considered. Here, we report our experience in correcting neprholithiasis by simply discontinuing topiramate without administering any additional treatments.

Glutaric Aciduria Type 1 in Korea: Report of Two Novel Mutations

Glutaric aciduria type I (GA I) is an autosomal recessive disorder caused by a deficiency of glutaryl-CoA dehydrogenase. Although over 400 patients confirmed as GA I have been reported, reports from the Asian population had contributed to the minor proportion. We recently diagnosed two cases of GA I confirmed with mutational analysis. Here, we present their rather atypical clinical presentations with genetic characteristics for the first time in Korea. Profound developmental delay from birth, association of hearing loss, and neurological improvement after surgical intervention, were considered to be different clinical features from most reported cases. One patient was a compound heterozygote for p.Ser139Leu and p.Asp220Tyr, and the other for p.Ser139Leu and Glu160X. The mutations of the two alleles (p.Asp220Tyr and p.Glu160X) were novel and reports of p.Ser139Leu were rare both in Western and other Asian populations. These might suggest different genetic spectrum of Korean GA I patients.

Efficacy and Safety of Levetiracetam in Children Younger than 4 Years with Intractable Epilepsy / 대한간질학회지

PURPOSE: The aim of this study was to evaluate the efficacy and safety of levetiracetam in children younger than 4 years with intractable epilepsy. METHODS: A retrospective analysis of pediatric epilepsy patients was performed. Data were obtained from the medical records of 30 patients (male 19, female 11) with intractable epilepsy, who were treated with levetiracetam. RESULTS: Seizure types were partial in 18, and generalized in 12. Fifteen patients had symptomatic etiologies. The median age of the patients at the time of levetiracetam administration was 26 months old (range: 4-47 months). The median starting dose was 13 mg/kg/ day, and the median maintenance dose was 52 mg/kg/day (range: 10-123 mg/kg/day). Ten (10/30, 33%) patients experienced more than 50% reduction in seizure frequency, and 4 (4/30, 13%) partial epilepsy patients became seizure-free. Eight partial epilepsy patients (44%) had more than 50% seizure reduction, while 2 patients (17%) with generalized epilepsy did. All of patients with infantile spasms and Lennox-Gastaut syndrome except one, had less than 50% reduction in seizure frequency. Adverse events reported in 8 patients (27%), included lethargy, behavioral problems, sleep disturbance, and seizure aggravation. CONCLUSIONS:Levetiracetam is effective in children aged 4 years or less with intractable epilepsy, and also seems to be safe to use in this age group.