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Featured researches published by Jin S. Hahn.


Lancet Neurology | 2007

Clinical features and viral serologies in children with multiple sclerosis: a multinational observational study

Brenda Banwell; Lauren B. Krupp; Julia Kennedy; Raymond Tellier; Silvia Tenembaum; Jayne Ness; Anita Belman; Alexei Boiko; Olga Bykova; Emmanuelle Waubant; Jean K. Mah; Cristina A. Stoian; Marcelo Kremenchutzky; Maria Rita Bardini; Martino Ruggieri; Mary Rensel; Jin S. Hahn; Bianca Weinstock-Guttman; E. Ann Yeh; Kevin Farrell; Mark S. Freedman; Matti Iivanainen; Meri Sevon; Virender Bhan; Marie-Emmanuelle Dilenge; Derek Stephens; Amit Bar-Or

BACKGROUND The full spectrum of clinical manifestations and outcome, and the potential importance of regional or demographic features or viral triggers in paediatric multiple sclerosis (MS), has yet to be fully characterised. Our aim was to determine some of these characteristics in children with MS. METHODS 137 children with MS and 96 control participants matched by age and geographical region were recruited in a multinational study. They underwent structured clinical-demographic interviews, review of academic performance, physical examination, disability assessment (MS patients only), and standardised assays for IgG antibodies directed against Epstein-Barr virus, cytomegalovirus, parvovirus B19, varicella zoster virus, and herpes simplex virus. FINDINGS MS was relapsing-remitting at diagnosis in 136 (99%) children. The first MS attack resembled acute disseminated encephalomyelitis (ADEM) in 22 (16%) of the children, most under 10 years old (mean age 7.4 [SD 4.2] years). Children with ADEM-like presentations were significantly younger than were children with polyfocal (11.2 [4.5] years; p<0.0001) or monofocal (12.0 [3.8] years; p=0.0005) presentations. Permanent physical disability (EDSS>or=4.0) developed within 5 years in 15 (13%) of the 120 children for whom EDSS score was available. 23 (17%) had impaired academic performance, which was associated with increasing disease duration (p=0.02). Over 108 (86%) of the children with MS, irrespective of geographical residence, were seropositive for remote EBV infection, compared with only 61 (64%) of matched controls (p=0.025, adjusted for multiple comparisons). Children with MS did not differ from controls in seroprevalence of the other childhood viruses studied, nor with respect to month of birth, sibling number, sibling rank, or exposure to young siblings. INTERPRETATION Paediatric MS is a relapsing-remitting disease, with presenting features that vary by age at onset. MS in children might be associated with exposure to EBV, suggesting a possible role for EBV in MS pathobiology.


Electroencephalography and Clinical Neurophysiology | 1992

Detection of neonatal seizures through computerized EEG analysis

A Liu; Jin S. Hahn; G.P Heldt; Ronald Coen

Neonatal seizures are a symptom of central nervous system disturbances. Neonatal seizures may be identified by direct clinical observation by the majority of electrographic seizures are clinically silent or subtle. Electrographic seizures in the newborn consist of periodic or rhythmic discharges that are distinctively different from normal background cerebral activity. Utilizing these differences, we have developed a technique to identify electrographic seizure activity. In this study, autocorrelation analysis was used to distinguish seizures from background electrocerebral activity. Autocorrelation data were scored to quantify the periodicity using a newly developed scoring system. This method, Scored Autocorrelation Moment (SAM) analysis, successfully distinguished epochs of EEGs with seizures from those without (N = 117 epochs, 58 with seizure and 59 without). SAM analysis showed a sensitivity of 84% and a specificity of 98%. SAM analysis of EEG may provide a method for monitoring electrographic seizures in high-risk newborns.


Pediatrics | 2010

Decrease in hospital-wide mortality rate after implementation of a commercially sold computerized physician order entry system.

Christopher A. Longhurst; Layla Parast; Christy Sandborg; Eric Widen; Jill Sullivan; Jin S. Hahn; Christopher G. Dawes; Paul J. Sharek

BACKGROUND: Implementations of computerized physician order entry (CPOE) systems have previously been associated with either an increase or no change in hospital-wide mortality rates of inpatients. Despite widespread enthusiasm for CPOE as a tool to help transform quality and patient safety, no published studies to date have associated CPOE implementation with significant reductions in hospital-wide mortality rates. OBJECTIVE: The objective of this study was to determine the effect on the hospital-wide mortality rate after implementation of CPOE at an academic childrens hospital. PATIENTS AND METHODS: We performed a cohort study with historical controls at a 303-bed, freestanding, quaternary care academic childrens hospital. All nonobstetric inpatients admitted between January 1, 2001, and April 30, 2009, were included. A total of 80 063 patient discharges were evaluated before the intervention (before November 1, 2007), and 17 432 patient discharges were evaluated after the intervention (on or after November 1, 2007). On November 4, 2007, the hospital implemented locally modified functionality within a commercially sold electronic medical record to support CPOE and electronic nursing documentation. RESULTS: After CPOE implementation, the mean monthly adjusted mortality rate decreased by 20% (1.008–0.716 deaths per 100 discharges per month unadjusted [95% confidence interval: 0.8%–40%]; P = .03). With observed versus expected mortality-rate estimates, these data suggest that our CPOE implementation could have resulted in 36 fewer deaths over the 18-month postimplementation time frame. CONCLUSION: Implementation of a locally modified, commercially sold CPOE system was associated with a statistically significant reduction in the hospital-wide mortality rate at a quaternary care academic childrens hospital.


Neurology | 1996

Intravenous gammaglobulin therapy in recurrent acute disseminated encephalomyelitis

Jin S. Hahn; David J. Siegler; Dieter R. Enzmann

Acute disseminated encephalomyelitis (ADEM) is a demyelinating disorder of the CNS that seems to be immune mediated. [1,2] It is usually preceded by a viral syndrome and presents with acute neurologic signs. [1] ADEM is usually monophasic, but recurrent episodes may occur. [3] When ADEM is recurrent, the distinction from MS becomes difficult. [2] Corticosteroids are commonly used in ADEM and are thought to shorten the duration of the neurologic symptoms. [4] We report on the use of intravenous gammaglobulin (IVIG) therapy for ADEM after failure of corticosteroids. An 8-year-old previously healthy boy developed headaches and fever 2 weeks before admission to Packard Childrens Hospital at Stanford. He was admitted to a community hospital. Vital signs were normal except for a temperature of 100.9 degrees F. There were no signs of meningeal irritation. LP showed 23 WBC/mm3 (34% polymorphonuclear cells, 45% lymphocytes, 21% monocytes), 0 RBC/mm3, with a protein of 23 mg/dL and a glucose of 63 mg/dL. MRI showed prominent leptomeningeal enhancement but no other lesions. He was diagnosed with viral meningitis and treated with IV acylovir for 9 days. Headaches worsened despite analgesics, and he was transferred to the Childrens Hospital. On examination, he was awake but in significant distress from a severe headache. His speech and comprehension were normal. Vital signs were normal except for a temperature of 100.7 degrees F. The general examination was unremarkable. There were several beats of ankle clonus, and the plantar responses were extensor bilaterally. The …


Electroencephalography and Clinical Neurophysiology | 1996

Predictive value of EEG for outcome and epilepsy following neonatal seizures

E.L. Ortibus; John M. Sum; Jin S. Hahn

The value of the electroencephalogram in predicting outcome and epilepsy was examined in neonates who had experienced EEG-confirmed neonatal seizures. Electroencephalogram, neuroimaging studies, and other clinical variables were systematically analyzed in 81 consecutive neonates with EEG-confirmed seizures. The surviving subjects were followed for a mean of 17 months to determine if they developed post-neonatal seizures (PNS) and abnormal neurodevelopmental outcome. Several EEG variables were correlated with neurodevelopmental outcome and PNS when analyzed with univariate and multivariate statistical analyses. The EEG background activity and the presence of status epilepticus were strong predictors of outcome, but were not associated with PNS. The presence of rhythmic theta-alpha bursts was highly favorable for both outcome and PNS. In the interictal EEG, the number of negative sharp waves in the temporal region correlated with outcome and PNS. Clinical variables associated with unfavorable outcomes included an abnormal neonatal neurologic exam and certain seizure etiologies (e.g. cerebral dysgenesis and infections). Global abnormalities on neuroimaging studies were invariably associated with an unfavorable outcome and with the development of PNS in 66% of cases. Using multivariate analysis, prediction of outcome (favorable versus unfavorable) was accurately achieved in 85% of cases when combining EEG variables with neuroimaging and clinical findings. In conclusion, in neonates with EEG-confirmed seizures, the EEG is a useful predictor of outcome, but is a less useful predictor of PNS.


American Journal of Medical Genetics Part C-seminars in Medical Genetics | 2010

Neuroimaging advances in holoprosencephaly: Refining the spectrum of the midline malformation†

Jin S. Hahn; Patrick D. Barnes

Holoprosencephaly (HPE) is a complex congenital brain malformation characterized by failure of the forebrain to bifurcate into two hemispheres, a process normally completed by the fifth week of gestation. Modern high‐resolution brain magnetic resonance imaging (MRI) has allowed detailed analysis of the cortical, white matter, and deep gray structural anomalies in HPE in living humans. This has led to better classification of types of HPE, identification of newer subtypes, and understanding of the pathogenesis. Currently, there are four generally accepted subtypes of HPE: alobar, semilobar, lobar, and middle interhemispheric variant. These subtypes are defined primarily by the degree and region of neocortical nonseparation. Rather than there being four discrete subtypes of HPE, we believe that there is a continuum of midline neocortical nonseparation resulting in a spectrum disorder. Many patients with HPE fall within the border zone between the neighboring subtypes. In addition, there are patients with very mild HPE, where the nonseparation is restricted to the preoptic (suprachiasmic) area. In addition to the neocortex, other midline structures such as the thalami, hypothalamic nuclei, and basal ganglia are often nonseparated in HPE. The cortical and subcortical involvements in HPE are thought to occur due to a disruption in the ventral patterning process during development. The severity of the abnormalities in these structures determines the severity of the neurodevelopmental outcome and associated sequelae.


Pediatrics | 1998

Wernicke Encephalopathy and Beriberi During Total Parenteral Nutrition Attributable to Multivitamin Infusion Shortage

Jin S. Hahn; William E. Berquist; Deborah Alcorn; Lisa Chamberlain; Dorsey Bass

Objective. Wernicke encephalopathy (WE) is an acute neurologic disorder characterized by a triad of ophthalmoplegia, ataxia, and mental confusion. WE is attributable to thiamine (vitamin B1) deficiency. Beriberi is the systemic counterpart of thiamine deficiency and often manifests in cardiovascular collapse. WE is usually associated with alcoholism and malnutrition. It has also been seen in people with gastrointestinal diseases with malabsorption. Patients who have received total parenteral nutrition (TPN) without proper replacement of thiamine have also developed WE. Since November 1996, there has been a shortage of multivitamin infusion (MVI). Many patients who were on chronic TPN with MVI ceased to receive the MVI and were converted to an oral form of the multivitamin. As a result, there have been several reports of children and adults on TPN who have developed WE as a result of thiamine deficiency. With this case report, we bring to attention the association of the MVI shortage and WE. Early diagnosis of WE is important, because if it is treated with thiamine in the acute stages, the neurologic and cardiovascular abnormalities can be reversed. Case Report. We report a 20-year-old female patient with Crohns disease who developed WE as a result of thiamine deficiency. She had Crohns disease since age 9 years and was on chronic TPN. Two months before admission, MVI was discontinued in the TPN because of the shortage of its supply. An oral multivitamin tablet was substituted instead. She was admitted to the hospital for persistent vomiting. In the hospital, she continued to receive TPN without MVI, but continued taking an oral multivitamin preparation. Two weeks after admission, she developed signs of WE including diplopia, ophthalmoplegia, nystagmus, and memory disturbance. She also developed hypotension that was thought to be caused by beriberi. She was treated with 50 mg of intravenous thiamine. Within hours of the intravenous thiamine, her hypotension resolved. The day after the infusion, she no longer complained of diplopia, and her ophthalmoplegia had improved dramatically. Magnetic resonance imaging showed several areas of abnormally high signal on T2-weighted images in the brainstem, thalamus, and mamillary bodies. The topographic distribution of these changes was typical of WE. After 2 months, her mental status and neurologic status had recovered completely. Conclusion. WE and thiamine deficiency should be considered in all patients with malabsorption, malnutrition, and malignancies. WE from thiamine deficiency can occur as a result of cessation of MVI in the TPN infusion. Even if an oral multivitamin preparation is given instead of MVI, patients with malabsorption may not absorb thiamine adequately. Prompt diagnosis of WE is important because it is potentially fatal and readily treatable with thiamine supplementation. Early recognition of WE may be more difficult in children, because the classic triad of symptoms may not develop fully. Magnetic resonance imaging may be useful in these cases to confirm the diagnosis of WE. Because the shortage of MVI is expected to be a long-term, there are likely to be more cases of WE in the pediatric population of TPN-dependent children. Because there is no shortage of intravenous thiamine, it should be administered with TPN even if MVI is not available.


Neurology | 2002

Neuroanatomy of holoprosencephaly as predictor of function Beyond the face predicting the brain

Lauren L. Plawner; Mauricio R. Delgado; Van S. Miller; Eric Levey; Stephen L. Kinsman; A. J. Barkovich; Erin M. Simon; Nancy J. Clegg; V. T. Sweet; Elaine E. Stashinko; Jin S. Hahn

BackgroundDespite advances in neuroimaging and molecular genetics of holoprosencephaly (HPE), the clinical spectrum of HPE has remained inadequately described. Objective To better characterize the clinical features of HPE and identify specific neuroanatomic abnormalities that may be useful predictors of neurodevelopmental function. Methods The authors evaluated 68 children with HPE in a multicenter, prospective study. Neuroimaging studies were assessed for the grade of HPE (lobar, semilobar, and alobar), the degree of nonseparation of the deep gray nuclei, and presence of dorsal cyst or cortical malformation. Results In general, the severity of clinical problems and neurologic dysfunctions correlated with the degree of hemispheric nonseparation (grade of HPE). Nearly three-quarters of the patients had endocrinopathies, with all having at least diabetes insipidus. The severity of endocrine abnormalities correlated with the degree of hypothalamic nonseparation (p = 0.029). Seizures occurred in approximately half of the children with HPE. The presence of cortical malformations was associated with difficult-to-control seizures. The presence and degree of dystonia correlated with the degree of nonseparation of the caudate and lentiform nuclei and the grade of HPE (p < 0.05). Hypotonia correlated with the grade of HPE (p < 0.05). Mobility, upper extremity function, and language correlated with the degree of nonseparation of the caudate, lentiform and thalamic nuclei, and grade of HPE (p < 0.01). ConclusionsPatients with HPE manifest a wide spectrum of clinical problems and neurologic dysfunction. The nature and severity of many of these problems can be predicted by specific neuroanatomic abnormalities found in HPE.


Neurology | 2002

Middle interhemispheric variant of holoprosencephaly: A distinct cliniconeuroradiologic subtype

Ann J. Lewis; Erin M. Simon; A. J. Barkovich; Nancy J. Clegg; Mauricio R. Delgado; Eric Levey; Jin S. Hahn

Background: The middle interhemispheric variant (MIH) is a subtype of holoprosencephaly (HPE) in which the posterior frontal and parietal areas lack midline separation, whereas more polar areas of the cerebrum are fully cleaved. While the neuroradiologic features of this subtype have been recently detailed, the clinical features are largely unknown. Objective: To present the clinical manifestations of MIH and to compare them with classic subtypes (alobar, semilobar, and lobar) of HPE. Methods: The authors evaluated 15 patients with MIH in a multicenter study. Neuroimaging and clinical data were collected and correlated. They compared the data with those of 68 patients who had classic HPE. Results: The frequency of endocrinopathy in MIH (0%) was lower compared with the classic subtypes (72%) (p < 0.0001). This correlated with the lack of hypothalamic abnormalities. The percentage of patients with seizures (40%) did not significantly differ from classic HPE. Spasticity was the most common motor abnormality, seen in 86% of MIH patients, similar to other subtypes. The frequency of choreoathetosis in MIH (0%) was lower than that for semilobar HPE (41%) (p < 0.0039). This correlated with the lack of caudate and lentiform nuclei abnormalities. Developmental functions, including mobility, upper-extremity function, and language, of the MIH group were similar to the least severe classic type, lobar HPE. Conclusion: MIH is a recognizable variant of HPE with differing clinical prognosis. Similar to the lobar subtype by functional measures, MIH differs from classic HPE by the absence of endocrine dysfunction and choreoathetosis.


Electroencephalography and Clinical Neurophysiology | 1989

Interburst interval measurements in the EEGs of premature infants with normal neurological outcome

Jin S. Hahn; Hannelore Monyer; Barry R. Tharp

Interburst intervals (IBIs) are quiescent periods of cerebral activity, which normally occur in the electroencephalograms (EEGs) of premature infants. Although it is generally felt that the duration of these intervals shorten with increasing conceptional age (CA), no systemic studies of IBIs have been done in a large group of normal premature infants with long-term follow-up and using multichannel routine EEGs. In this study, we measured the IBIs, using defined criteria, in 36 premature infants who were normal at 3 years. The IBIs were measured in 104 EEGs, obtained from these infants, using standard recording techniques. Mean and the maximum IBIs were calculated. IBI duration decreased with increasing CA, although this trend was not very prominent when very restrictive criteria for measurement of IBI length were used. Less restrictive criteria for defining an IBI led to trends which are similar to those of previous studies. Various clinical factors, such as mild encephalopathies, small intraventricular/subependymal hemorrhages, mild bronchopulmonary dysplasia, or patent ductus arteriosus did not significantly alter IBI durations. Comparison with other techniques of IBI measurement and recording are discussed. The longest period of continuous activity during a routine recording was also measured and was found to increase with increasing CA.

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Nancy J. Clegg

Texas Scottish Rite Hospital for Children

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Eric Levey

Kennedy Krieger Institute

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Erin M. Simon

Children's Hospital of Philadelphia

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Benjamin D. Solomon

National Institutes of Health

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Felicitas Lacbawan

National Institutes of Health

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