Jeehun Lee

Neurodevelopmental Outcomes in Preterm Infants: Comparison of Infants with and without Diffuse Excessive High Signal Intensity on MR Images at Near–term-equivalent Age

PURPOSE To compare the neurodevelopmental outcomes between preterm infants with diffuse excessive high signal intensity (DEHSI) and those without DEHSI on magnetic resonance (MR) images, in association with other white matter lesions. MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and requirement to obtain informed consent was waived. High-risk preterm infants (n = 126) who underwent screening brain MR imaging at near-term-equivalent age were classified into two groups according to the presence of DEHSI. Bayley Scales of Infant Development-II, presence of cerebral palsy, and neurosensory impairment between 18 and 24 months of age were compared between the two groups. The associations of MR findings of other white matter lesions (cystic encephalomalacia, punctate lesions, loss of volume, ventricular dilatation, and delayed myelination) and subsequent outcomes were also analyzed. Outcome data were evaluated by using exact logistic regression analyses and Fisher exact test. RESULTS DEHSI was present in 75% (95 of 126) of infants. Subsequent neurodevelopmental outcomes did not differ significantly between the two groups. Severe motor delay and cerebral palsy were more common in infants with both DEHSI and other white matter lesions as compared with infants with normal white matter (P = .001 and P < .001, respectively). Among other white matter lesions, cystic encephalomalacia (odds ratio, 19.6; 95% confidence interval: 1.3, 333.3) and punctate lesions (odds ratio, 90.9; 95% confidence interval: 6.4, 1000) were significant predictors of cerebral palsy. CONCLUSION Although the incidence of DEHSI was high (75%) in preterm infants at near-term-equivalent age MR imaging, DEHSI was not predictive of following adverse outcomes. Cystic encephalomalacia and punctate lesions were more significant predictors of cerebral palsy.

The role of ketogenic diet in the treatment of refractory status epilepticus

Ketogenic diet (KD) is known to be effective in intractable epilepsy. However, the role of KD in refractory status epilepticus (RSE) has not been well described. The aim of this study is to explore the role of KD in patients with RSE. We retrospectively reviewed the medical records of four children and one adult with RSE between October 2006 and August 2010. All presented with status epilepticus (SE) that was presumed to be associated with viral encephalitis. After we failed to control the seizures with standard measures for SE, we tried KD. The overall seizure frequency decreased to <50% of baseline in median eight (1–19) days. At one month of KD, two patients were seizure‐free, one patient showed >90% seizure reduction, and the others had >75% decrease without generalized seizures. With improvement in the RSE, we were able to taper the antiepileptic drugs (AEDs) and wean patients from prolonged mechanical ventilation. The adverse events of KD in RSE included aspiration pneumonia, gastroesophageal reflux, constipation, and hypertriglyceridemia. Those results demonstrate that KD can be a valuable therapeutic option for patients with RSE.

Dysembryoplastic neuroepithelial tumors in pediatric patients

OBJECTIVE Dysembryoplastic neuroepithelial tumors (DNTs) are benign cortical tumors that are frequently associated with the medically intractable focal epilepsy. In this study, the authors delineate the clinical characteristics of DNTs in children and evaluate the role of cortical dysplasia (CD) in the epileptogenicity to find out the optimum surgical strategy. METHODS A retrospective analysis was performed for clinical data of children with DNT, who underwent surgery between 1996 and 2006. The adopted surgical methods were uniform according to the tumor location and included intraoperative electrocorticography (ECoG)-guided resection. The prognostic factors were evaluated for the two prognostic group categorized by the seizure outcome at one year after surgery. RESULTS Of 22 patients, the overall seizure free rate was 90.9% and the other two patients belonged to Engel class II during the mean follow-up period of 44.1 months. There was no worsening of the seizure after one year of surgery. Associated CD was found in 18 cases (81.8%) and in the 80% (8 of 10 cases) of the additionally resected areas according to the electrophysiologic studies. CONCLUSIONS The CD associated with DNT appears to have its own epileptogenicity. Therefore, complete removal of the CD with tumor itself is important for patient outcome. A thorough surgical approach can be accomplished by comprehensive presurgical evaluations and extensive surgery with the aid of the intraoperative ECoG or intracranial recording.

Genetic Analysis of Dystrophin Gene for Affected Male and Female Carriers with Duchenne/Becker Muscular Dystrophy in Korea

Duchenne and Becker muscular dystrophy (DMD/BMD) are X-linked recessive disorders caused by mutation in dystrophin gene. We analyzed the results of a genetic test in 29 DMD/BMD patients, their six female relatives, and two myopathic female patients in Korea. As the methods developed, we applied different procedures for dystrophin gene analysis; initially, multiplex polymerase chain reaction was used, followed by multiplex ligation-dependent probe amplification (MLPA). Additionally, we used direct DNA sequencing for some patients who had negative results using the above methods. The overall mutation detection rate was 72.4% (21/29) in DMD/BMD patients, identifying deletions in 58.6% (17/29). Most of the deletions were confined to the central hot spot region between exons 44 and 55 (52.9%, 7/19). The percentage of deletions and duplications revealed by MLPA was 45.5% (5/11) and 27.2% (3/11), respectively. Using the MLPA method, we detected mutations confirming their carrier status in all female relatives and symptomatic female patients. In one patient in whom MLPA revealed a single exon deletion of the dystrophin gene, subsequent DNA sequencing analysis identified a novel nonsense mutation (c.4558G > T; Gln1520X). The MLPA assay is a useful quantitative method for detecting mutation in asymptomatic or symptomatic carriers as well as DMD/BMD patients.

Improvement of CNS Defects Via Continuous Intrathecal Enzyme Replacement by Osmotic Pump in Mucopolysaccharidosis Type II Mice

Mucopolysaccharidosis type II (MPS II), also known as Hunter syndrome (OMIM 309900), is a rare, X‐linked lysosomal storage disorder caused by a deficiency of iduronate‐2‐sulfatase (IDS; EC 3.1.6.13), which is involved in the lysosomal degradation of glycosaminoglycans (GAG). Although intermittent intrathecal (IT) injection of the enzyme has been introduced as a method to overcome the blood‐brain barrier, continuous IT infusion of the enzyme would be more physiologic. This study was performed to investigate responses in the brain of MPS II mice to varying doses of continuous IT infusion of recombinant human IDS (rh‐IDS) in MPS II mice by osmotic pump in three different doses (2.4, 4.8, and 12 µg/day) of rh‐IDS for 3 weeks. The results showed that the group treated with 12 µg/day doses of rh‐IDS demonstrated decreased GAG concentrations compared to the untreated KO mice group (P = 0.003). After 3 weeks of continuous IT ERT, the brain tissues of the high‐dose IT‐treated KO mice showed a reduction of vacuolation in the cerebral cortex, thalamus and cerebellar cortex, which was not observed in the low‐ and medium‐dose KO mice groups. Moreover, the anti‐NeuN signal representing intact neuron was restored in the cortexes of the high‐dose group. In conclusion, continuous IT infusion of the deficient enzyme was effective in improving CNS defects in the MPS II mice, and could be a valuable therapeutic method for treating neurological deterioration in patients with MPS II.

Clinical and genetic analysis of Korean patients with congenital insensitivity to pain with anhidrosis

Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal recessive disease characterized by anhidrosis, insensitivity to noxious stimuli, and mental retardation. Mutations in the NTRK1 gene are associated with the pathogenesis of CIPA. In this study, we performed a clinical and genetic analysis on the NTRK1 gene in four Korean patients with CIPA. All patients had typical clinical manifestations of CIPA, including anhidrosis, recurrent fever, absent pain perception, and developmental delay. Sequencing analysis revealed one predominant mutation, c.851‐33T>A, in four affected alleles and three novel mutations, including c.287+2dupT, c.2155G>A (p.Glu719Lys), and c.1218delC (p.Pro407ArgfsX), in each affected allele. For one patient, who was heterozygous for c.851‐33T>A, another mutation could not be identified, suggesting that a possible hidden intronic or large genomic mutation may have been present. This study extends the spectrum of mutations in the NTRK1 gene and confirms that Korean patients with CIPA have the same genetic background as other ethnicities. Muscle Nerve, 2009

Clinical features and genetic analysis of children with hyperekplexia in Korea.

Hyperekplexia is a rare inherited neurologic disorder that is characterized by hypertonia and an exaggerated startle response to sudden external stimuli. Until now, 5 genes are known to be associated with hyperekplexia: GLRA1, SLC6A5, GLRB, GPHN, and ARHGEF9. In this report, we performed a clinical and genetic analysis of 4 Korean children with hyperekplexia. Two patients had typical clinical manifestations of hyperekplexia that initially were misdiagnosed as epilepsy. Direct sequencing of the GLRB and GLRA1 genes revealed 2 novel mutations, GLRB c.298-1G>A and c.1028C>T (p.S343F), in patient 1 and 1 novel mutation, GLRA1 c.895C>T (p.R299X), in patient 2. The other 2 familial cases, patients 3 and 4, exhibited startle responses, which appeared at the age of 1 year, and had global developmental delay. Those patients showed negative results for the 5 genes.

Clinical manifestations and treatment response of steroid in pediatric Hashimoto encephalopathy.

Hashimoto encephalopathy is a steroid-responsive encephalopathy associated with elevated titers of antithyroid antibodies. Clinical symptoms are characterized by behavioral and cognitive changes, speech disturbance, seizures, myoclonus, psychosis, hallucination, involuntary movements, cerebellar signs, and coma. The standard treatment is the use of corticosteroids along with the treatment of any concurrent dysthyroidism. Other options are immunoglobulins and plasmapheresis. We described symptoms and outcomes on 3 teenage girls with Hashimoto encephalopathy. Presenting symptoms were seizure or altered mental status. One patient took levothyroxine due to hypothyroidism before presentation of Hashimoto encephalopathy. After confirmation of elevated antithyroid antibodies, all patients were treated with steroids. One patient needed plasmapheresis because of the lack of response to steroids and immunoglobulins. Hashimoto encephalopathy should be considered in any patient presenting with acute or subacute unexplained encephalopathy and seizures. Even though the use of steroids is the first line of treatment, plasmapheresis can rescue steroid-resistant patients.

The natural course of clinically isolated syndrome in pediatric patients

BACKGROUND The first episode of central nervous system (CNS) symptoms with a presumed inflammatory demyelinating cause is defined as clinically isolated syndrome (CIS) according to the 2007 consensus of the International Pediatric Multiple Sclerosis Study Group, which developed diagnostic criteria for CNS demyelination disease in children. Using this definition of CIS, we attempted to identify the natural course of pediatric patients with CIS in a single Korean institution and to determine the factors affecting their prognosis. METHODS We retrospectively reviewed the medical records of all pediatric patients (age <18 years old) who presented with clinical symptoms of CNS events between 1997 and 2008. RESULTS We identified 32 patients with CIS. Their mean age with standard deviation was 10.0±4.1 years. The most common type of presentation of CIS was optic neuritis (ON). Sixteen (16/32, 50%) patients experienced a second demyelinating event. The mean interval between the first event and the recurrent episode was 21±20 months. The mean follow-up was 6.1±1.6 years. Eleven (34%) patients developed childhood onset multiple sclerosis (MS). In contrast to previous studies, asymptomatic brain lesions on magnetic resonance imaging (MRI) and the presence of cerebrospinal fluid (CSF) oligoclonal bands (OCBs) were not predictors of conversion to MS. CONCLUSION In our study, a second relapse and initial presentation with brain stem, cerebellar, cerebral dysfunction, or multifocal CIS were strongly associated with the development of MS (p=0.002). Despite clinical definitions and increased understanding of CIS in children, challenges remain in predicting its progression to a chronic demyelinating disease.

Prognostic factors of infantile spasms: Role of treatment options including a ketogenic diet

OBJECTIVES The aim of this study was to provide additional evidences on prognostic factors for infantile spasms and the possible role of a ketogenic diet. METHODS A retrospective analysis was performed for patients with infantile spasms who had been followed up for more than 6months between January 2000 and July 2012 at Samsung Medical Center (Seoul, Republic of Korea). We analyzed the association between possible prognostic factors and seizure/developmental outcomes. RESULTS Sixty-nine patients were included in this study and their mean follow-up duration was 52.5 (9-147) months. In the patients who had been followed up for more than 2years, 53.6% (n=30/57) remained seizure-free at the last visit. Sixty patients (86.9%) showed developmental delay at last follow-up. Forty-two patients (60.9%) became spasm-free with one or two antiepileptic drugs, one patient with epilepsy surgery for a tumor, and seven patients with a ketogenic diet after the failure of two or more antiepileptic drugs. The etiology and age of seizure onset were the significant prognostic factors. CONCLUSIONS In this study, about 60% of the patients became spasm-free with vigabatrin and topiramate. Ketogenic diet increased the rate by 10% in the remaining antiepileptic drug resistant patients. However, 86.9% of the patients showed developmental delay, mostly a severe degree. Early diagnosis and prompt application of treatment options such as antiepileptic drugs, a ketogenic diet or epilepsy surgery can improve outcomes in patients with infantile spasms.