Persistent hypertransaminasemia as the presenting findings of muscular dystrophy in childhood

Prolonged elevation of the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) is often attributed to hepatic diseases. However, these enzymes are also present in a variety of extrahepatic tissues, including skeletal muscle. Five children (all boys) were referred to the pediatric department of the National Taiwan University Hospital because of persistent elevation of serum aminotransferase activities. The ages of these children were between 4 months and 5.5 years. The neurological findings were all not remarkable. The initial ALT and AST values were 114-581 U/L and 183-700 U/L, respectively. Serum creatine kinase was checked first after 0 to 30 months follow-up and found to be markedly elevated (range, 10,557 U/L to 62,508 U/L). Muscle biopsies in the five cases all showed degenerating and regenerating myofibers with interstitial fibrosis. In Cases 3, 4 and 5, complete absence of dystrophin immunoreactivity was found. Genetic studies showed deletions in the DMD gene (exons 45-48 in case 2 and 49-50 in case 4). This experience indicates that occult muscle diseases should be taken into account in patients with unexplained long-lasting hypertransaminasemia and therefore measurement of serum creatine kinase activity and muscle biopsy should be done early for the correct diagnosis of muscular dystrophy.

Displacement effect of valproate on bilirubin-albumin binding in human plasma

Drugs that can displace bilirubin from plasma albumin binding may cause various late manifestations of brain damage if given to newborns with unconjugated hyperbilirubinemia. The purpose of this study was to examine the displacement effect of valproate (VPA) on bilirubin-albumin binding in human serum albumin (HSA) and human plasma. Bilirubin-HSA solution and bilirubin-plasma solution containing no or serial concentrations of VPA were prepared, and free bilirubin in these solutions was measured by the enzyme oxidation method. VPA displaced bilirubin from bound bilirubin-albumin. The binding constant (KD) of VPA to the high affinity bilirubin-binding site of HSA and plasma protein were 11.6 L/mmol and 9.0 L/mmol respectively. The displacement effect may occur at the clinical concentration range of VPA, with a maximal displacing factor of 1.5 to 4.7. These results suggest that the clinician should use VPA in jaundiced neonates with caution.

Muscle phosphofructokinase deficiency (Tarui's disease): report of a case

A 14-year-old girl had an acute episode of rhabdomyolysis after vigorous exercise and seizures. Laboratory studies revealed elevated creatine phosphokinase (CPK) activity and myoglobinuria without acute renal failure, as well as mild indirect hyperbilirubinemia, and hyperuricemia. The elevated CPK activity, mild indirect hyperbilirubinemia, and hyperuricemia persisted during a 10-month follow-up period, during which chronic hemolysis without overt anemia was also noted. A muscle biopsy specimen from the left biceps muscle revealed occasional muscle fiber necrosis and mild excess of glycogen accumulation on periodic acid-Schiff staining. Histochemical reactions were negative with phosphofructokinase (PFK) stain when fructose-6-phosphate was used as the substrate, but positive when fructose 1,6-bisphosphate was used as the substrate. These findings confirmed the diagnosis of muscle PFK deficiency (Tarui's disease), which is a defect of glycolysis in muscles and erythrocytes. Less than 40 such patients have been reported to date. When a specific metabolic myopathy is suspected in children with rhabdomyolysis, symptoms of hemolysis should also be sought to identify Tarui's disease. To the best of our knowledge, this is the first case of Tarui's disease identified in Taiwan.

Vocal cord paralysis and hypoventilation in a patient with suspected Leigh disease

The authors report the case of a 16-month-old male with suspected Leigh disease, which was diagnosed on the basis of the clinical manifestations, abnormal lactate stimulation test, proton magnetic resonance spectroscopy, and neuroradiologic findings. Progressive stridor resulting from bilateral vocal cord paralysis and hypoventilation was evident. The authors suggest that for infants or children who exhibit vocal cord paralysis, mitochondrial disorders, such as Leigh disease, should be considered.

Pathologic features of initial adenomas as predictors for metachronous adenomas of the rectum

BACKGROUND

Colorectal cancer is the third most common cancer in the world, arising mostly from pre-existing adenomatous polyps (adenomas) of the large bowel. Patients with colorectal adenomas are at increased risk of colorectal cancer because of a high recurrence rate for adenomas. We followed a cohort of 1490 patients with rectal adenomas to determine whether recurrence might be related to pathologic characteristics of the initial adenomas.

METHODS

The patients were identified in Haining County, China, from 1977 through 1978 by means of examination with a 15-cm rigid sigmoidoscope. They were followed by endoscopic examination at years 2, 4, 6, 11, and 16 after their initial polypectomy. New adenomas in the rectum were identified in 280 patients in these follow-up examinations.

RESULTS

Statistically significant twofold to threefold elevated risks of metachronous (recurrent) adenomas were observed for patients who had more than two initial adenomas or whose most advanced initial adenoma was more than 1.0 cm in size, was of villous/tubulovillous type, or showed moderate to severe dysplasia. Much stronger associations were observed for advanced metachronous neoplasms, which are defined as cancers or adenomas with severe dysplasia, with multivariate adjusted relative risks (95% confidence interval) of 4.2 (1.8-9.9) for a large initial adenoma (>1.0 cm), 8.1 (4.2-15.6) for villous/tubulovillous architecture, and 14.4 (5.0-41.3) for severe dysplasia. In particular, patients who had a large (>1.0 cm) adenoma with severe dysplasia at baseline had a relative risk of 37 (7.8-174.7) of developing advanced metachronous neoplasms compared with patients who had small adenoma(s) with mild dysplasia.

CONCLUSIONS

The risk of metachronous adenomas is closely related to the pathology of initial adenomas, thus allowing identification of a high-risk group of adenoma patients for close surveillance after their initial polypectomy.

The controversy regarding diagnostic criteria for early myoclonic encephalopathy

To re-evaluate the diagnostic criteria for early myoclonic encephalopathy (EME), the following study was done. During the past 2 years, five patients with erratic, fragmentary myoclonus of neonatal onset, in association with other types of seizures, were analyzed with regard to etiologies, electroclinical features and their evolution, using a series of examinations including electroencephalographies (EEGs) and metabolic investigations. Of these five patients, three were diagnosed to have non-ketotic hyperglycinemia (NKH); one was pyridoxine-dependent; the other was cryptogenic. Only two cases (one NKH and one cryptogenic) had initial typical suppression-burst (S-B) EEG pattern, which subsequently evolved into multiple paroxysmal abnormalities with random asynchronous attenuation (MP-AA) pattern. The other two cases with NKH had MP-AA EEG pattern throughout both awake and sleep recordings in two consecutive EEG studies. All three cases with NKH survived with increasing microcephaly, muscle tonicity; all developed infantile spasm with hypsarrhythmia on EEGs. The patient with pyridoxine-dependency had an initial MP-AA EEG pattern, which converted into S-B pattern after the first use of pyridoxine, eventually becoming normal after a supplement with the second-dose of pyridoxine. In conclusion, either S-B or MP-AA pattern may reflect the severity of the underlying pathologies or the disease stages. These results suggest that, from both etiological and electroclinical viewpoints, EME may represent a broader spectrum than previously recognized. The still ongoing controversy regarding whether the S-B pattern should be recognized as the sole EEG criteria for the diagnosis of EME needs further experience to clarify.

Intracranial arachnoid cysts in children: related signs and associated anomalies

Intracranial arachnoid cysts are benign development anomalies that may be clinically asymptomatic. The authors describe 30 children with intracranial arachnoid cysts in terms of clinical manifestations and relations to the associated brain anomalies or lesions. The mean age at onset of clinical manifestations was 4 years, 7 months (range 1 day to 14 years). The mean age at diagnosis was 6 years, 2 months (range 10 days to 16 years). Most patients with nonprogressive symptoms, such as seizures and headache, had focal epileptiform discharges on electroencephalogram, and they benefited from antiepileptic drugs. Surgery resulted in only partial reduction in both cyst size and seizure frequency in patients with intractable seizures, and it also failed to improve some neurologic signs, such as sexual precocity or cranial neuropathy resulting from long-term compression of arachnoid cysts. We conclude that the only absolute indication for surgery is the presence of progressive hydrocephalus or intracranial hypertension. The associated anomalies or lesions include brain tumors, giant nevocellular nevi, achondroplasia, microphthalmia, intracystic hemorrhage, dysgenesis of the corpus callosum, and heterotopia.

Strokes in children: a medical center-based study

Stroke is an important cause of mortality and morbidity in children. Cases of pediatric stroke admitted to National Taiwan University Hospital from January 1985 to December 1995 were reviewed. Patients whose stroke was obviously caused by premature birth, birth trauma or head injury were excluded. Totally 65 patients were enrolled, including 37 boys and 28 girls. Their ages ranged from birth to 18 years old. They were classified into two groups: ischemic stroke (38 patients) and hemorrhagic stroke (27 patients), according to the pathogenesis. The ages of onset, clinical manifestation, underlying diseases and treatment of these two groups were systematically analyzed. The major presenting symptoms of both ischemic and hemorrhagic strokes were motor deficit (65.8%) and consciousness disturbance (55.6%). A wide variety of diseases predisposing to strokes was identified. The major causes of hemorrhagic stroke were vascular malformation and oncologic conditions, with the latter, the most frequently encountered underlying diseases associated with childhood ischemic stroke. The mortality rate for hemorrhagic stroke was 37% and, for ischemic stroke, 21.1%. There was male predominance in pediatric stroke. Although the clinical symptoms and signs might provide some guidelines to differentiate between hemorrhagic and ischemic strokes, neuroimaging studies were crucial to more exact diagnosis. A variety of diseases may contribute to pediatric stroke. Early diagnosis determine treatability, then aggressive treatment are important.

Cancellation of low-frequency stimulation-induced long-term depression by docosahexaenoic acid in the rat hippocampus

The effects of docosahexaenoic acid (DHA) on low-frequency stimulation (LFS)-induced long-term depression (LTD) were investigated in the CA 1 subfield of rat hippocampal slices. LTD was routinely produced by LFS of 900 pulses at 1 Hz. The field excitatory postsynaptic potential (fEPSP) 40 min after LFS was 59 +/- 4% (n = 18) of baseline response. However, in experiments from 18 neurons pretreated with DHA (50 microM), fEPSP returned to baseline levels within 20 min after LFS in eight cells and was slightly potentiated in three cells. Only in seven cells was LTD induced. The effect of DHA on LTD was concentration dependent. The slopes of fEPSP 40 min after LFS were 67 +/- 4% (n = 6), 72 +/- 7% (n = 7) and 80 +/- 5% (n = 18) of baseline response, with pretreatment of 1, 10 and 50 microM DHA, respectively. The blockade of LTD induction suggests that DHA may play a role in learning and memory.

Effect of valproate on the pharmacokinetics of free and total plasma bilirubin in experimental hyperbilirubinemia in guinea pigs

The effects of valproate (VPA) on free and total bilirubin concentrations in plasma were studied in guinea pigs. Steady-state hyperbilirubinemia (around 2.5-3.0 mg/100 mL) was induced by constant intravenous (i.v.) infusion of bilirubin followed by an i.v. bolus dose of sodium valproate (VPA-Na) of 50 (n = 4) or 200 (n = 5) mg/kg. Steady-state plasma total bilirubin concentration was lowered by 40% and 55% and the unbound fraction (fu) increased by 1.9- and 4.9-fold at the respective doses of 50 mg/kg and 200 mg/kg VPA-Na. Free bilirubin was not significantly changed by 50 mg/kg VPA-Na, but did show a significant transient elevation with the 200 mg/kg dose. In another experiment, guinea pigs (n = 3) were given a constant i.v. infusion of VPA-Na to maintain a steady-state plasma concentration (58 micrograms/mL), followed by an i.v. bolus dose of bilirubin (2 mg/kg). A control study (n = 3) was performed simultaneously using normal saline instead of VPA. Free bilirubin was detectable only following induction of hyperbilirubinemia in either group. A higher volume of distribution and lower elimination rate constant of bilirubin were observed in the VPA-treated than in the control animals. The displacement effect of VPA on bilirubin-plasma binding in vitro was studied by adding serial concentrations of VPA-Na to bilirubin-plasma solution. VPA displaced bilirubin from the high-affinity plasma protein binding site, with a binding constant (KD) of 5.7 x 10(-2)/microM. Similar displacement of bilirubin plasma protein binding was observed in vivo. These results suggest that VPA reduces plasma protein binding and slows the elimination rate of bilirubin. The principal mechanism for decreased plasma concentrations of total bilirubin by administration of VPA is caused by decreased plasma binding, as opposed to metabolic induction.

Duplication of proteolipid protein gene: a possible major cause of Pelizaeus-Merzbacher disease

The classic form of Pelizaeus-Merzbacher disease is a rare X-linked dysmyelinating disorder of the central nervous system in which mutations of the proteolipid protein gene have been reported since 1989. However, mutations in the proteolipid protein gene have been identified in only 10 to 25% of all cases of Pelizaeus-Merzbacher disease, which suggests that other genetic aberrations may be present. Recently, proteolipid protein gene overdosage was discovered to cause Pelizaeus-Merzbacher disease. By using comparative multiplex polymerase chain reaction and restriction fragment length polymorphism analysis, we confirmed the proteolipid protein gene duplication as the cause of Pelizaeus-Merzbacher disease in 4 patients from 3 Chinese families with Pelizaeus-Merzbacher disease with no detectable exonic mutations. These results support the hypothesis that proteolipid protein gene duplication may be a major cause of Pelizaeus-Merzbacher disease in all ethnic groups and also suggest that the molecular diagnosis of Pelizaeus-Merzbacher disease should therefore include duplication analysis of proteolipid protein gene.

Magnetic resonance imaging in symptomatic/cryptogenic partial epilepsies of infants and children

In order to identify the brain lesions of symptomatic/cryptogenic partial epilepsies (S/CPEs) in infants and children, magnetic resonance imaging (MRI) studies, thorough encephalographic (EEGic) studies, and detailed clinical and neurologic evaluations were obtained in 300 infants and children who were diagnosed to have S/CPEs with onset before the age of 13 years during the past 7 years. The overall detection rate of brain lesions by MRI was 41.7% (125/300). Congenital malformations (18 cases), vascular malformations (9 cases), neurocutaneous syndromes (13 cases), and space-taking lesions (20 cases) constitute a large percentage of SPEs in infants and children. A variety of insults such as infection, ischemia, hemorrhage, trauma and metabolic disorders can result in destructive parenchymal loss lesions including porencephaly, focal atrophy, hemiatrophy, and diffuse brain atrophy (20 cases). Major etiologic factors leading to infarction, encephalomalacia, leukomalacia, included trauma, hvpoxicischemic encephalopathy (HIE), systemic lupus erythematosus (SLE), encephalitis, vasculitis, venous thrombosis, vasculopathies, and heart problems (22 cases). Mesial temporal sclerosis (MTS) could be evidenced in around 20% (18/95) of cases with temporal lobe epilepsy (TLE), which was strongly associated with past histories of febrile seizures and encephalitis complicated by status epileptics. However, cases with porencephaly, global atrophy or delayed myelination of unilateral temporal lobe on MRI were more related to HIE. With the advent of neuroimaging techniques, particularly MRI, a wide variety of underlying pathology can be detected as a cause of symptomatic partial epilepsies in pediatric patients. The occurrence of S/CPE indicates the presence of localized brain dysfunction, and many of the causes are potentially treatable. An orderly and thorough clinical and laboratory investigations, as well as neuroimaging studies should be made to diagnose and treat any underlying conditions.

Severe myoclonic epilepsy in infancy: evolution of electroencephalographic and clinical features

Since 1987, we have diagnosed 10 patients, 4 males and 6 females, aged 2-11 years at the last evaluation, who all met the following criteria of severe myoclonic epilepsy in infancy (SMEI): generalized or unilateral long-lasting febrile clonic seizures in the first year of life; the subsequent appearance of myoclonic seizures and other types of seizure (partial seizures, atypical absences and convulsive status epilepticus); and neuropsychological deterioration for a certain period. Family histories of epilepsy and febrile seizures could be traced in 1 and 3 cases, respectively. None of them had previous personal history of brain insult. Electroencephalographic (EEGic) recordings in febrile seizure stage were normal; and continuous prophylaxis with phenobarbital failed to prevent the recurrence of febrile seizures. EEG studies in myoclonic stage showed generalized spike-and-waves, polyspike-and-waves, focal abnormalities and/or photosensitivity. The seizures were highly resistant to antiepileptic drugs. Our experiences suggested that comedication of valproic acid, clonazepam and carbamazepine may be most effective in treatment of the diverse seizures including myoclonic seizures, myoclonic-tonic-clonic seizures, atypical absences and partial seizures. Myoclonic seizures and atypical absences diminished in parallel to a clear-cut decrease in generalized abnormalities on EEG in 4 cases aged more than 7 years. However, the partial seizures, secondarily generalized seizures and status epilepticus were still present. Further investigations should aim to identify the underlying etiology and to search more effective treatment.

Late infantile type neuronal ceroid lipofuscinosis: report of one case

A 4-year-10-month-old boy with late infantile type neuronal ceroid lipofuscinosis was reported. He presented with progressive dementia, loss of visual acuity, gradual regression of speech and motor functions, and myoclonic jerks. A hyperactive deep tendon reflex was noted, but there was neither muscle weakness nor hepatomegaly. Serum lactate, pyruvate and ammonia levels were within normal limits. The funduscopic examination showed diffuse mottling of the retinal pigmented epithelium. The electroencephalogram showed irregular bilateral spike-and-waves or polyspike-and-waves and isolated focal spikes from the bilateral parieto-occipital regions. The wave forms of visual evoked potentials were flat. The electroretinogram was unrecordable. The somatosensory evoked potentials showed prolonged central conduction times from bilateral median nerves. The brainstem auditory evoked potentials were within normal limits. Diffuse cerebral and cerebellar atrophy were noted on magnetic resonance imaging. The diagnosis was confirmed by the electron-dense cytoplasmic inclusion bodies within the conjunctival squamous epithelial cells. No specific treatment was available. Regular anticonvulsants were not given during follow-up because seizures attacked him only on occasion. His visual acuity was progressively impaired. In addition to nearly total absence of speech, an inability to communicate and walk independently was also noted. The clinical features according to the subtypes, radiology, pathology, managements and prenatal diagnosis for this case are discussed.

Cytochrome c oxidase deficiency in fibroblasts of a patient with mitochondrial encephalomyopathy

Cytochrome c oxidase (CCO) deficiency is associated with various types of mitochondrial encephalomyopathy. The enzyme activities in different tissues and organs are varied. We report an 11-year-old girl with CCO deficiency, who presented with nystagmus, ptosis and optic atrophy. Her younger sister died of respiratory failure at 7 years of age and had the same initial clinical manifestations. Their parents were consanguineous. The girl had mild mental retardation and frequent premature ventricular contractions. Brain magnetic resonance imaging of the patient on admission revealed multiple lesions in both the gray and white matter. Except for arrhythmia and marked right axis deviation of the heart on electrocardiography, no other evidence of cardiac involvement was noted. Although a muscle biopsy was normal for both histochemical stains and electron microscopy, the enzyme assays in cultured skin fibroblasts revealed partial CCO deficiency, which may explain the clinical presentations.

Glucuronidation metabolic kinetics of valproate in guinea pigs: nonlinear at clinical concentration levels

PURPOSE

Nonlinear conjugation metabolic rate of valproic acid (VPA) has been speculated previously from plasma elimination and liver concentration of VPA in guinea pigs. The purposes of the present study were to assess our speculation by direct measurement of VPA glucuronidation rate in vitro.

METHODS

VPA at various concentrations (10-200 micrograms/ml) was incubated with guinea-pig liver-homogenate, mitochondria or microsome in the presence of cofactor, uridine 5'-diphosphoglucuronic acid (UDPGA). The maximum glucuronidation rate (Vmax) and Michaelis-Menten constant (Km) of VPA were determined.

RESULTS

On a body weight basis, the Vmax and the Km values of VPA glucuronidation estimated from liver homogenate were 1.8 mumol/min/kg and 0.3 mumol/ml, respectively; and that from microsome suspension were 1.2 mumol/min/kg and 0.16 mumol/ml, respectively. These data are comparable with the primary metabolic parameters observed from previous in vivo study. The glucuronidation clearance calculated from these parameters was 0.10-0.48 fraction of total clearance, which was in agreement with the reported data observed from clinical and animal urinary recoveries of VPA-G. The glucuronidation reaction was not detectable in mitochondria suspension.

CONCLUSIONS

The glucuronidation kinetics of VPA is nonlinear and saturable within clinical concentration range. Estimation of in vivo VPA glucuronidation kinetics from in vitro kinetic parameters is feasible.

Rotavirus gastroenteritis associated with afebrile seizure in childhood

From September 1994 to April 1995, we encountered eight children, two boys and six girls, (aged 1 year 6 months to 9 years), presented with acute diarrhea followed by afebrile, generalized tonic-clonic seizures, or transient loss of consciousness with urine incontinence. Their biochemical data, including serum electrolyte levels, were within normal limits. The infective agent causing diarrhea was later proved by stool examination to be rotavirus, judged to be serotype G1 by reverse transcription - polymerase chain reaction (RT-PCR) typing. Cerebrospinal fluid (CSF) examinations performed in seven of the eight patients were within normal limits, and cultures for bacteria and virus were negative. The electroencephalograms (EEGs) performed from 1 to 13 days after seizure showed abnormal in six, and normal in two, patients. Follow-up EEGs, performed from 4 to 11 months after onset of seizure, were all normal. None had seizure recurrence despite the fact that no long-term anticonvulsant had been given. From observation here, the authors emphasize that there is a close relationship between rotavirus and afebrile seizure, and the course of afebrile seizure following rotavirus gastroenteritis is usually benign. Further studies are needed to elucidate the underlying pathogenesis.

Acute disseminated encephalomyelitis in children: clinical, neuroimaging and neurophysiologic studies

Nine patients below 20 years of age (4 males and 5 females), who were diagnosed to have acute disseminated encephalomyelitis (ADEM) by clinical findings and magnetic resonance imaging (MRI), were reviewed retrospectively. They ranged from 4 months to 20 years of age with an average of 8.6 years. Seven patients (78%) received neurophysiological studies, which included electroencephalography, multimodality evoked potentials (EPs), nerve conduction velocity and/or F-wave measurement. The presentation symptoms were mainly headache, vomiting, consciousness change and motor deficits. Seven (78%) of nine patients had symptoms preceded by fever or upper respiratory tract infections; one (11%) was preceded by trivalent mumps, measles, rubella vaccination and no definite predisposing factor was found in another. Computed tomography (CT) scans were abnormal in five (71 %) of seven children, while MRI showed multiple lesions in seven (78%) of nine children. The lesions in MRI were mainly in the brainstem (n = 6), basal ganglion (n = 5), thalamus (n = 4), periventricular white matter (n = 4) and cerebellum (n = 4). EPs disclosed spinal cord involvement in all patients who received the examination. Peripheral neuropathy was disclosed in one patient. It was concluded that associated radiculoneuropathy is possible in patients with ADEM. Both MRI and neurophysiologic studies are complementary for diagnosis of ADEM.

Dose-dependent distribution volumes of total and unbound valproate in guinea-pigs: consequence of non-linear plasma protein binding

The response of steady-state distribution volume (Vdss for total and Vdssu for unbound drug) of valproate (VPA) to dose-dependent plasma protein binding was studied in guinea-pigs. Various steady-state plasma concentrations of VPA were achieved by intravenous constant infusion. The concentrations of VPA in plasma (Css for total and C(uss) for unbound drug) and various tissues (CT) were determined. The Vdss and the Vdssu were estimated based upon the apparent tissue-to-plasma concentration ratio of VPA. The results showed that the plasma unbound fraction (fu) of VPA increased significantly with dose. The Vdss was significantly increased with, while the Vdssu was significantly decreased against the increasing dose. The increase in Vdss with dose indicated an increase in tissue-to-plasma concentration ratio, which may be attributed to the increase in distribution of unbound drug from plasma to tissues subsequent to non-linear plasma protein binding. The decrease in Vdssu against the increasing dose indicated a decrease in tissue-to-unbound plasma concentration ratio, which suggests that the extravascular distribution of unbound VPA might be capacity limited and the tissue binding of VPA negligible.

Thenar hypoplasia in Klippel-Feil syndrome due to aberrant radial artery

A 10-year-old boy with Klippel-Feil syndrome had progressive atrophy of the left thenar eminence and absence of left radial pulse. Neurophysiologic studies and angiography were normal. However, duplex sonography over the wrists revealed an aberrant left radial artery. We speculate that the thenar atrophy in this patient is congenital, which may be due to the anomaly of the left radial artery, and is further compromised by vascular compression in the thoracic outlet.

Cerebral venous thrombosis in children

From May 1984 to April 1995, a total of 16 patients (12 females, 4 males) with cerebral venous thrombosis, diagnosed by computed tomography (CT), conventional cerebral angiography, magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA), were reviewed retrospectively. The age ranged from 1 month to 16 years of age (average: 2.5 years) with 8 below 1 year of age. The presenting symptoms for infants were mental change (75%) and seizure (100%), mainly generalized (63%) in character. Associated illness was mainly closed head injury, diarrhea or dehydration. All infants had mild to severe motor handicap in a 1 to 10 year follow-up. In contrast, older children frequently presented with headache (37%) or consciousness change (50%), and were more frequently associated with sepsis or local infections. Four (50%) of them recovered completely, but two died and two were finally in a vegetative state. For the four patients with poor prognosis, all had severe initial insults and widespread sinus thrombosis. MRI and MRA are better than CT for the diagnosis of cerebral venous thrombosis. It was concluded that prognosis for venous thrombosis cases in infants is worse than in older children, but this also depends on the severity of initial insults. For infants who present with intractable seizures, cerebral venous thrombosis should be taken into account when the seizures are difficult to control.

Analysis of tissue distribution of valproate in guinea-pigs: evidence for its capacity-limited tissue distribution

The tissue distribution of valproic acid (VPA) was investigated over a wide range of steady-state plasma levels (Css) in guinea-pigs. The VPA concentrations in various tissues, except the kidney, were all lower than in plasma. Tissue-to-unbound plasma concentration ratios (Kpu) of VPA for adipose, heart, kidney, liver, lung, muscle, pancreas and skin all decreased significantly with increasing unbound plasma concentration (Cuss). The Kpu for brain (0.5-0.9), intestine, spleen and stomach failed to show significant change with Cuss. The disposition of VPA in tissues is adequately described by a model in which VPA was distributed in interstitial and intracellular fluid and bound to interstitial albumin, with limited tissue binding. Tissue binding was extensive only in the kidney. Most of the measured apparent Kpu values agreed well with simulated Kpu values. Steady-state tissue concentration of VPA can be predicted from Css and Cuss when reference data for interstitial albumin and tissue total water are available.

Multiple sclerosis in children: clinical, neuroimaging, and neurophysiological correlations

Four female children with clinically-definite diagnoses of multiple sclerosis (MS) were studied with multimodal evoked potentials (EPs), electroencephalogram (EEG), cerebrospinal fluid (CSF) analysis, computed tomography (CT) and magnetic resonance imaging (MRI). Correlations among the clinical features, neuroimaging and neurophysiological studies were also evaluated. Their ages of the onset ranged from 5 to 11 years. The clinical evolution in the all four MS cases was relapsing-remitting form. MRI studies in three cases showed abnormal demyelinating plaques in the brainstem, cerebellum and white matter of the cerebrum. CT examination, performed in the other MS case, did not reveal hypodensic lesion. Despite that MRI failed to document optical nerve lesions, three cases had abnormal visual evoked potentials (VEPs). Somatosensory evoked potentials (SSEPs) were abnormal in three cases. Brainstem auditory evoked potentials (BAEPs) were abnormal in two cases presenting with signs of brainstem dysfunction. The conclusion was that paraclinical evidences obtained from MRI and multimodal evoked potential studies are of value as an aid in localizing involved areas and detecting silent lesions in children with MS.

Child neurology in Taiwan, ROC: past, present and future

The status of child neurology in Taiwan is analysed as to three stages, i.e., past, present and future. The year of demarcation between the past and present is set arbitrarily at 1988, when the academic organization changed. Each stage is reviewed from four aspects--academic organization of subspecialty training and research, change in disease pattern, diagnostic procedure, and treatment.

Neurophysiologic studies and MRI in Pelizaeus-Merzbacher disease: comparison of classic and connatal forms

Four patients with the classic form and 1 patient with the connatal form of Pelizaeus-Merzbacher disease were studied with magnetic resonance imaging, electroencephalography, and multimodal evoked potentials, including brainstem auditory evoked potentials, somatosensory evoked potentials, and visual evoked potentials. Comparisons between these findings were made. It was determined that the neurophysiologic studies, particularly brainstem auditory evoked potentials, are of value in early diagnosis of Pelizaeus-Merzbacher disease; brainstem auditory evoked potentials with only normal wave I may be a relatively reliable clue suggesting the classic form of Pelizaeus-Merzbacher disease in patients with nystagmus and chronic progressive encephalopathy. Magnetic resonance imaging allows an accurate assessment of the degree of hypomyelination; however, the clinical severity of various forms of Pelizaeus-Merzbacher disease seemed to be independent of the age of onset and the amount of residual myelin. The following may be distinguishing features between the connatal and classic forms of Pelizaeus-Merzbacher disease: hypoplasia of the cerebellum and brainstem, and diffuse brain atrophy on magnetic resonance imaging; optic atrophy with abnormal visual evoked potential; seizure disorder with abnormal electroencephalography, and/or auditory nerve impairment with abnormal wave I of brainstem auditory evoked potentials in the early stage of the disease.