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Biomedical subjects

K L Hung

Publications and source records attributed to K L Hung.

At least 19 recordsLinked to original sources

The spectrum of postinfectious encephalomyelitis.

The medical records of 52 consecutive patients diagnosed with postinfectious encephalitis/encephalomyelitis during the period from 1980 to 1998, including 29 males and 23 females, were reviewed. These patients were divided into three groups according to their clinical and neurodiagnostic characteristics: (1) group I: postinfectious encephalitis, 38 patients; (2) group II: acute disseminated encephalomyelitis (ADEM), 13 patients; (3) group III: multiphasic disseminated encephalomyelitis (MDEM), one patient. Fever, headache/vomiting, seizure and disturbance of consciousness were common clinical features in all patients, while pictures of pyramidal, extrapyramidal, brainstem, and spinal cord lesions were more often found in the group II and group III patients than in the group I patients. Magnetic resonance imaging (MRI) revealed abnormal lesions in six (60%) of ten group I patients, but all group II (n=7) and group III (n=1) patients who received MRI study showed abnormal signals in various regions of the brain including the cerebral hemisphere, basal ganglia, brainstem and cerebellum. Patients with ADEM and MDEM had a longer clinical course and more neurological sequelae than group I patients. This study demonstrates the breadth of the clinical spectrum of postinfectious encephalomyelitis. Thorough clinical observations and appropriate neurodiagnostic studies such as MRI are crucial for the diagnosis.

Brain↗

Spontaneous closure of ventricular septal defects in the first year of life.

BACKGROUND AND PURPOSE: The recent increase in the prevalence of ventricular septal defect (VSD) has been ascribed to the improved detection of small defects with echocardiography and the wider use of screening. The aim of this study was to determine the prevalence and timing of spontaneous closure of specific types of VSD in neonates using echocardiographic screening and follow-up. METHODS: Two-dimensional color Doppler echocardiography was performed in 3,472 clinically normal full-term neonates born at Cathay General Hospital to detect isolated VSD. The relative prevalence of muscular versus perimembranous defects and their outcome in the first year of life were evaluated. RESULTS: VSD was found in 74 neonates (34 male, 40 female), resulting in a prevalence of 21.3/1,000 live births. There were 48 muscular, 25 perimembranous, and one subpulmonic defects. Of the 74 patients, 11 were lost to follow-up. Within the observation period of 12 months, spontaneous closure occurred in 40 patients in the muscular group and in six patients in the perimembranous group. The overall rate of spontaneous closure was 73% by the end of the first year. Only five patients with perimembranous defects received digoxin therapy. CONCLUSIONS: The prevalence of VSD in this series of neonates was 21.3/1,000 live births. The most common location of VSD in the neonatal period was in the region of the muscular septum. Muscular defects were more likely to close spontaneously than perimembranous defects. Most muscular defects underwent spontaneous closure during the 12-month follow-up period.

Age Factors↗

Postinfectious encephalomyelitis: etiologic and diagnostic trends.

Fifty cases of postinfectious encephalomyelitis admitted to our Pediatric Department during the period 1980 to 1997 were consecutively collected and reviewed. There were 28 males and 22 females. The age of onset ranged from 9 months to 14 years. The antecedent infections included measles (6 cases), rubella (5 cases), mumps (4 cases), chicken pox (4 cases), Epstein-Barr virus infection (11 cases), mycoplasma infection (6 cases), and unknown etiology (14 cases). The cessation of measles, rubella, and mumps as causes for encephalomyelitis in our patients corresponds with the introduction of a measles-mumps-rubella nationwide vaccination program in Taiwan commencing in 1992. The main clinical symptoms were fever, headache, and/or vomiting, seizure, and motor weakness. The presenting signs included altered consciousness, meningeal signs, cranial nerve palsy, brainstem signs, involuntary movement, and cerebellar signs. Computed tomography scans were abnormal for 14 (56%) of 25 patients studied, whereas magnetic resonance imaging (MRI) disclosed lesions in 14 (82%) of 17 patients, with abnormal signals in various parts of the cerebral hemisphere, as well as in the basal ganglion, diencephalon, midbrain, brain stem, and cerebellum. Of the three patients with negative MRI findings, an abnormal finding on somatosensory evoked potential was noted for one patient, and a focal decrease in tracer uptake on single photon emission computed tomography (SPECT) was found for the other two patients. This study demonstrates that the causative agents of postinfectious encephalomyelitis in Taiwan have changed from those of traditional exanthematous diseases to nonspecific respiratory infections and suggests that this may also be the case in other parts of the world. MRI remains the imaging method of choice, whereas other neurofunctional studies such as evoked potentials and SPECT are complementary for the diagnosis.

Adolescent↗

Topographic mapping and clinical analysis of benign childhood epilepsy with centrotemporal spikes.

We studied the topographic mapping of the electroencephalography (EEG) of 47 children whose clinical history and course were compatible with typical benign childhood epilepsy with centrotemporal spikes (BCECT). Twenty-nine (62%) patients showed typical dipole fields, with a negative potential field in the centrotemporal region and a positive field in the frontal region. Eighteen children did not demonstrate the typical dipole field. Their non-dipole rolandic discharges were localized in small fields of centrotemporal region. The patients with dipole fields in BCECT had significantly less frequent seizures than patients without dipole fields. Twelve of the 47 patients with BCECT (26%) had more than one EEG focus. The clinical courses of patients with multiple foci were not worse than those of patients with a single focus. We conclude that EEG topographic mapping is helpful in identifying typical or atypical EEG topographic patterns in patients with clinically diagnosed BCECT. We also conclude that the presence of dipole field usually indicates a better clinical course of epilepsy and multiple foci do not mean a poor clinical course.

Action Potentials↗

Neonatal jaundice and molecular mutations in glucose-6-phosphate dehydrogenase deficient newborn infants.

Molecular mutations of the glucose-6-phosphate dehydrogenase (G6PD) gene and clinical manifestations of neonatal jaundice in 112 male and 50 female Chinese neonates with G6PD deficiency were studied. In the 112 males, the nucleotide (nt) 1376 (G-->T) mutation was the dominant type (50.0%), followed by nt 1388 (G-->A) (16.1%), nt 493 (A-->G) (8.0%), nt 1024 (C-->T) (6.2%), nt 95 (A-->G) (5.4%), nt 392 (G-->T) (1.8%), nt 487 (G-->A) (1.8%), nt 871 (G-->A) (0.9%), and nt 1360 (C-->T) (0.9%). The nt 871 variant has not been reported in Taiwan before. The occurrence rates for nt 1376, nt 1388, nt 493, nt 95, and nt 1024 mutations in the 50 females were 44.0%, 18.0%, 12.0%, 6.0%, and 6.0%, respectively. The type of G6PD mutation in 10 male and 7 female neonates has not been identified yet. Although G6PD deficient neonates had higher frequency of phototherapy than G6PD normal neonates in both sexes, a significant difference in the prevalence of hyperbilirubinemia (peak bilirubin > or = 15.0 mg/dl) between G6PD deficient and normal neonates was found only in males. Further analysis showed that duration of phototherapy was longer in G6PD deficient male neonates than in the control group, while the outcome of phototherapy was better in subjects with non-nt 1376 mutations than subjects with the nt 1376 mutation. Most (78.3%) of the 23 G6PD deficient neonates who subsequently suffered from neonatal hyperbilirubinemia carried the nt 1376 mutation. The results of this study indicate that the nucleotide substitution at 1376 is the most common and important mutation for G6PD deficiency in Chinese neonates in Taiwan.

Base Sequence↗

Risk factors for subsequent epilepsy after febrile convulsions.

To evaluate the risk of subsequent epilepsy after febrile convulsions and the long-term prognosis of such patients, the risk factors for afebrile seizures following initial febrile convulsions were studied in 154 hospitalized children: 122 with simple febrile convulsions and 32 with complex features of febrile convulsions. The mean follow-up period was 7 years 2 months (range, 4 yr - 11 yr 2 mo). Nineteen patients (12.3%) developed subsequent epilepsy in the follow-up period. The seizure types in patients with subsequent epilepsy following febrile convulsions included generalized seizures in seven patients, complex partial seizures in five patients, partial seizures evolving to secondary generalized seizures in six patients and benign childhood epilepsy with centrotemporal spike in one patient. The occurrence of epilepsy was strongly associated with complex features of febrile convulsions, pre-existing neurodevelopmental abnormalities, family history of epilepsy, and abnormal electroencephalographic findings. However, the number of recurrences of febrile convulsions, sex, family history of febrile convulsions, age of onset and long-term prophylactic use of anticonvulsants for febrile convulsions were not significant factors for subsequent epilepsy. This study demonstrates the importance of identifying the risk factors for subsequent afebrile seizures after febrile convulsions.

Adolescent↗

Blood-brain barrier damage in children with central nervous system infections.

The blood-brain barrier (BBB) function in childhood central nervous system (CNS) infections was evaluated, using cerebrospinal fluid (CSF) and paired serum samples from 30 controls and 74 patients aged from 1 to 15 years with various CNS infections. The 74 patients included 34 cases of aseptic meningitis, 24 of encephalitis and 16 of purulent meningitis. The degree of BBB damage was graded by CSF/serum albumin ratio, and IgG production by IgG index (IgG ratio/albumin ratio of CSF to serum). In the acute stage, patients with purulent meningitis had greater elevation of the albumin ratio than other study groups. The patients with encephalitis, especially chronic encephalitis, had a selectively elevated IgG index compared to other groups. Most patients with aseptic meningitis showed little or no elevation of albumin ratio and IgG index. This study demonstrated the nature of various degrees of BBB damage and intra-BBB IgG production in different infectious CNS diseases in children. BBB damage is most severe in cases of purulent meningitis, while the intrathecal IgG production is greatest in chronic encephalitis. These abnormalities disappear as the inflammatory processes subside.

Adolescent↗

[Unilateral thalamic tumor with atrophy of ipsilateral cortical cortex: report of a case].

Ipsilateral brain atrophy is rare in neoplastic lesions of the brain, but it has been reported in patients with a thalamic tumor. We report a Chinese boy who presented with a right focal motor seizure and right side weakness at the age of six and half years when an electroencephalogram (EEG) showed focal epileptic discharges over the left hemisphere, but computed tomography (CT) of the brain failed to reveal a definite mass lesion. The weakness became gradually worse. On admission at age 8, follow-up CT scan revealed a huge tumor (5 x 5 x 7 cm) compressing the third and lateral ventricles with mixed densities in the left thalamus and centrum semiovale. The scan after contrast infusion showed a marked enhancement of the tumor. Instead of peri-mass edema surrounding the tumor, the overlying cerebral tissue showed atrophy of the ipsilateral cortical layer. He received subtotal resection of the tumor. The pathology proved to be germinoma. A test of tumor markers revealed a high human chorionic gonadotrophin level in the blood and cerebrospinal fluid. A short course of radiotherapy and chemotherapy was given after surgery. He has been well for the past two years.

Atrophy↗

[Clinical and cellular biologic diagnosis of Cockayne syndrome: a case report].

We report a case of Cockayne syndrome. A 6-year-old boy presented with a progeroid face, dwarfism, psychomotor retardation, skin photosensitivity and retinal pigmented degeneration. Neurological study disclosed slowed nerve conduction velocities and a brain CT showed calcification in the basal ganglia. Auditory brain stem evoked potential showed prolonged interpeak latency of wave I to wave V. Laboratory evaluation revealed mild liver dysfunction and peripheral eosinophilia. Fibroblast cultures from the patient and his family were exposed to ultraviolet (UV) light of 254 nm, ranging from 1 to 10 J/m2. Under 1 J/m2 irradiation, the surviving fraction of the fibroblasts from the patient, his mother, and a control subject were 40%, 50%, 90% respectively. If the fibroblasts of these subjects were exposed to 2 J/m2 and 3 J/m2 irradiation, the surviving fraction changed to 10%, 22%, 80% and 1.5%, 9%, 68%, respectively. However, fibroblasts from his sister and father showed the same surviving fraction as the control. The study showed that fibroblasts from the patient and his mother were extremely sensitive to UV light irradiation. We also study the concentration of the pyrimidine dimer of DNA in the patient and the control subject. Pyrimidine dimer showed no difference between the patient and the normal subject before and after 24-hour UV irradiation. These results suggest that the sensitivity to UV of Cockayne fibroblasts may be due to a ligase deficiency or to a replicon initiation disturbance in Cockayne cells.

Cell Survival↗

Diagnostic value of cerebrospinal fluid immunoglobulin G (IgG) in pediatric neurological diseases.

A total of 71 cerebrospinal fluid (CSF) specimens with paired serum samples from 16 controls and 55 patients with various neurologic diseases ranging in age from 1 to 15 years old were studied using a rate nephelometer to measure their immunoglobulin G (IgG) and albumin levels in both their CSF and serum. The patients included 15 cases of encephalitis, 6 cases of purulent meningitis, 20 cases of aseptic meningitis, 2 cases of multiple sclerosis and 12 cases of other noninflammatory neurologic diseases. The values of the CSF IgG quotient, IgG index, and de novo central nervous system (CNS) IgG synthesis were then calculated for each subject. In the control group, the mean values were as follows: CSF IgG, 1.45 mg/dl; IgG quotient, 6.2%; IgG index, 0.55; and de novo IgG synthesis, -1.17 mg/day. Those with CNS inflammatory diseases had significantly higher CSF IgG levels and IgG quotients compared with controls (p less than 0.05). The IgG index was selectively elevated in cases of encephalitis (p less than 0.005). The values for de novo IgG synthesis showed significant increase in all types of CNS inflammatory diseases except for the group with aseptic meningitis. In the noninflammatory diseases, none of the CSF parameters revealed any significant differences from those of the control group. Six cases (40%) of encephalitis showed normal CSF protein value, but an abnormal IgG component, IgG index and de novo IgG synthesis. Quantitation of IgG and other derivatives in CSF gives a sensitive supplementary reference for the detection of CNS infection.

Adolescent↗

Familial medulloblastoma in siblings: report in one family and review of the literature.

Two siblings in a family--a 5-year-old boy and an 8-year-old girl--suffered from progressive headache and gait disturbance in an interval of 1 year, consecutively. Neurologic manifestations were papilledema and truncal ataxia. Both of their computed tomography scans showed a large, well-enhanced tumor located in the cerebellar vermis with secondary hydrocephalus. Both had surgical resection followed by craniospinal irradiation and then chemotherapy. The pathologic findings confirmed the diagnosis of medulloblastomas. The family pedigree disclosed some other cancer in close relatives. These findings suggested a possible role of heredity in the oncogenesis of this tumor. To our knowledge, our cases are the seventh report of familial medulloblastoma occurring in nontwin siblings in the world.

Brain Neoplasms↗

Post-hepatitic aplastic anaemia in children in Taiwan, a hepatitis prevalent area.

Aplastic anaemia is a rare but serious complication of hepatitis, and hepatitis is an unusual cause of aplastic anaemia in children in the West. However, the relative frequencies of acquired aplastic anaemia in children in Taiwan, a hepatitis prevalent area, differ from those in the West, in the very high frequency of post-hepatitic aplastic anaemia (23.9% of all cases of aplastic anaemia). This may account for the higher incidence of aplastic anaemia in children in Taiwan. Although the prognosis of post-hepatitic severe aplastic anaemia was very poor, the present study using bone marrow transplantation, antithymocyte (or antilymphocyte) globulin, high-dose methylprednisolone and cyclosporin, etc., has improved the response rate and the survival.

Adolescent↗

Cerebral blood flow velocity in newborn infants with asphyxia.

A pulsed-Doppler real-time technique was used to assess the anterior cerebral artery (ACA) flow velocity in 30 asphyxiated infants during the first 5 days after birth. Thirty healthy term infants were also studied as controls. Peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), mean flow velocity (MFV), and pulsatility index (PI) were measured. Mean PI values of the ACA of the asphyxiated and control groups were 0.63 +/- 0.05 vs 0.71 +/- 0.04 (p less than 0.001) on the first day; 0.64 +/- 0.03 vs 0.70 +/- 0.05 (p less than 0.001) on the third day and 0.69 +/- 0.04 vs 0.70 +/- 0.04 (p greater than 0.05) on the fifth day of life. The asphyxiated group also had significantly higher EDFV and MFV than those of control group until the 5th day of life. The low PI values of asphyxiated infants were mainly due to an increase in EDFV. These results suggest that the cerebrovascular resistance of asphyxiated infants, as reflected by the PI, is low during the first 3 days of life, indicating an increase in cerebral blood flow. With this technique, we can repeatedly and safely evaluate the cerebral hemodynamic changes in asphyxiated newborn infants.

Asphyxia Neonatorum↗

Subacute necrotizing encephalomyelopathy (Leigh's disease): report of a case.

A 5-month-old male infant was referred to us for evaluation of progressive hypotonia. He had growth retardation, feeding difficulty and general weakness. Brain sonography and computed tomography demonstrated symmetrical lesions in the caudate, lenticular nuclei, thalamus and hypothalamus, suggesting bilateral necrosis. Lactate and pyruvate levels in the blood and cerebral spinal fluid were persistently elevated. A biopsy of the quadriceps muscle showed increased subsarcolemmal mitochondrial enzyme activity on light microscopy. Electron microscopy of the muscle showed deformed and bizarre mitochondria. The patient eventually died at the age of 8 months. Autopsy showed bilateral necrotic foci in the caudate, lenticular nuclei, thalamus, hypothalamus, midbrain, and pons. Histopathologic findings included spongiform degeneration of the affected brain tissue. The characteristic clinical and pathological findings confirmed this case as subacute necrotizing encephalo-myelopathy of Leigh's type. To our knowledge, this is the first autopsy-proven case of Leigh's disease in Taiwan.

Humans↗

Brain abscesses in children--a cooperative study of 83 cases.

This study reviews our experience in 83 cases of brain abscesses in children diagnosed at seven teaching hospitals during the 10-year period from June 1978 to July 1987. The average age of the patients was 7 years, with 12% of them less than 1 year old. The male-to-female ratio was 1.7:1. Of the brain abscesses, 90.4% were detected by CT brain scan. A total of 50.6% patients had congenital heart disease, and 20.4% patients had sepsis and/or meningitis. Only 6% cases had ear, nose, and throat infection. Sixty-eight (81.9%) patients received a combination of antibiotics and surgical treatment. The cerebral abscesses were totally excised in 26 cases, aspirated and partially excised in 6, and aspirated in 32. Sixty patients had pus cultures from the cerebral abscesses. Organisms were isolated in 29 (49.2%) of them. Streptococcus was by far the most common organism. The overall outcome was: 49 (59%) alive; 16 (19.3%) dead; 18 (21.7%) lost to follow-up. Among the 16 mortalities, the causes of death were due to failure to treat the diseases causing the brain abscesses. We had a better outcome in patients whose cerebral abscesses were totally excised or whose abscesses were aspirated, and in patients who were older than 1 year of age.

Adolescent↗

Auditory brainstem responses in patients with neonatal hyperbilirubinemia and bilirubin encephalopathy.

To understand the neurotoxicity of neonatal hyperbilirubinemia, auditory brainstem response (ABR) studies were performed in 75 jaundiced patients, who were divided into 4 groups in either a retrospective or prospective way. Retrospective ABR study in 10 known kernicteric patients (group I) showed elevation of the hearing threshold and delay of wave I, as well as prolongation of central brainstem transmission, in various degrees, in most cases. Six jaundiced infants (group II) with ABR testing before and after blood exchange transfusion (BET) showed shortening of wave latencies and increase in amplitude after BET. There were additional 20 infants with BET (group III) and 39 with phototherapy (group IV) receiving ABR testing after the therapeutic procedures. Prospective follow-up in groups II, III and IV showed normalization of the ABRs in all except one patient in the following months. These findings demonstrate the nature of bilirubin neurotoxicity and the prognostic value of ABRs in the monitoring of bilirubin toxicity. ABR testing is sensitive in reflecting the effect of hyperbilirubinemia, and provides a valuable guide for the early recognition and close follow-up of bilirubin neurotoxicity.

Bilirubin↗

Congenital poisoning by polychlorinated biphenyls and their contaminants in Taiwan.

In 1979, a mass poisoning occurred in Taiwan from cooking oil contaminated by thermally degraded polychlorinated biphenyls. Because these chemicals persist in human tissue, children born to female patients after the outbreak were exposed in utero. In 1985, 117 children born to affected women and 108 unexposed controls were examined and evaluated. The exposed children were shorter and lighter than controls; they had abnormalities of gingiva, skin, nails, teeth, and lungs more frequently than did controls. The exposed children showed delay of developmental milestones, deficits on formal developmental testing, and abnormalities on behavioral assessment. These findings are most consistent with a generalized disorder of ectodermal tissue. This syndrome is one of very few documented to result from transplacental exposure to pollutant chemicals.

Conjunctivitis↗