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Biomedical subjects

H J Christen

Publications and source records attributed to H J Christen.

At least 37 records · Page 2Linked to original sources
PubMed1997

Aromatic L-amino acid decarboxylase deficiency: an extrapyramidal movement disorder with oculogyric crises.

Aromatic L-amino acid decarboxylase (AADC) deficiency results in an impaired synthesis of catecholamines and serotonin, and has been reported only in two middle eastern families. We report on a European family with an affected child. The child showed the characteristic clinical picture of an extrapyramidal movement disorder, oculogyric crises and vegetative symptoms seen in the three patients described previously. Treatment with a combination of the AADC cofactor pyridoxine, the monoamine oxidase B inhibitor selegiline and bromocriptine was started during the fifth year of life and showed only a moderate clinical improvement in contrast to patients who have been treated since the first year of life.

Amino Acid Metabolism, Inborn Errors↗
PubMed1996

Localized proton magnetic resonance spectroscopy of a cerebellar tumor in a two-year-old child.

Noninvasive localized proton magnetic resonance spectroscopy (MRS) was used for differential diagnosis of a focal brain lesion in a 2.5-year-old girl. The clinical signs were a mild head tilt and neck pain. Magnetic resonance imaging (MRI) revealed a lesion in the right hemisphere of the cerebellum, but its nature remained obscure. In this lesion quantitative determinations of cerebral metabolites by fully relaxed, short-echo-time proton MRS revealed markedly lowered N-acetylaspartate (NAA) and pronounced elevations of choline-containing compounds (Cho) and myo-inositol (Ins), whereas metabolite concentrations in cortical gray matter and white matter were within normal ranges. The metabolite pattern of the lesion indicated loss of vital neuroaxonal tissue (low NAA) and enhanced glial proliferation (high Cho and Ins), which, together with the MRI morphology, suggested a brain tumor. The diagnosis was established by neurosurgical exploration and total extirpation of the tumor. Histology confirmed an astrocytoma (WHO II). After 2 weeks' recovery the child was discharged with no neurological signs.

Astrocytoma↗
PubMed1996

Intra-axial endophytic primitive neuroectodermal tumors in the pons: clinical, radiological, and immunohistochemical aspects in four children.

We present the clinical findings, radiological aspects, operative results, and histopathological features of four typical primitive neuroectodermal tumors (PNET) located in the pontine region in children. All the tumors had an endophytic intra-axial growth pattern. All the children had a short history of severe neurological deficits with involvement of the cranial nerves and pyramidal tract. MRI did not reveal any common feature of malignancy. Compared to our successful experience in operations of intra-axial endophytic brainstem tumors in a total of 32 children, the outcome was poor: all 4 children died within 13 months. We conclude that PNET occurring in the pons is not as rare as was believed, and, compared to PNET in other areas the prognosis is worse.

Actins↗
PubMed1996

Use of transcranial real-time ultrasonography for programming a shunt valve system.

For patients who suffer from hydrocephalus that is difficult to treat because of impaired intracranial compliance, a programmable shunt system may be a helpful alternative. However, especially during the first weeks after implantation, many radiological follow-up studies are necessary to achieve the optimum pressure level. The authors present the case of a 7-year-old boy who suffered from posthemorrhagic hydrocephalus and did not respond to conventional shunt valve systems. After implantation of a programmable shunt system, achieving the optimum craniospinal fluid (CSF) pressure level was difficult because the symptoms of over- and under-drainage were similar. Using transcranial real-time ultrasonography for evaluation of the diameter of the intracranial CSF spaces, we were able to adjust the correct pressure level without long-term intracranial pressure monitoring or daily computed tomography, which otherwise would have been necessary because of the ambiguous symptomatology. Transcranial real-time ultrasonography (TCUS) displays an image of the intracranial parenchyma and CSF spaces through the intact temporal bone and is a valuable, serially applicable bedside monitoring technique for patients requiring close imaging follow-up.

Cerebral Hemorrhage↗
PubMed1996

Immunohistochemistry of primary central nervous system malignant rhabdoid tumors: report of five cases and review of the literature.

Malignant rhabdoid tumors (MRT) are characterized by a typical light microscopic morphology with uniformly round tumor cells, vacuolated cytoplasm with occasional round, hyaline intracytoplasmic, periodic acid-Schiff-positive inclusions, vesicular nuclei with prominent nucleoli and positive immunoreactivity for vimentin. The histogenesis of MRT is controversial. Five cases of primary central nervous system (CNS) rhabdoid tumors in children are presented. Immunohistochemical, light and electron microscopic features are compared with primary CNS malignant rhabdoid tumors reported in the literature. Expression of various neurofilaments in our cases of primary CNS rhabdoid tumors was prominent and we therefore favor a neural differentiation of extrarenal intracerebral rhabdoid tumors.

Brain Neoplasms↗
PubMed1996

Localized proton magnetic resonance spectroscopy of cerebral metabolic disturbances in children with neuronal ceroid lipofuscinosis.

Cerebral metabolic abnormalities in five children with infantile (1), late infantile (1), and juvenile (3) neuronal ceroid lipofuscinosis (NCL) were noninvasively assessed by localized proton magnetic resonance spectroscopy (MRS). Infantile NCL was characterized by a complete loss of N-acetylaspartate (NAA, neuronal marker), a marked reduction of creatines (Cr) and choline-containing compounds (Cho), and an elevation of myo-inositol (Ins, glial marker) and lactate (Lac) in both gray and white matter. Reduced NAA and elevated Lac were also detected in gray and white matter of late infantile NCL, but in this case not only Ins but also Cr and Cho were increased in white matter. In contrast to the infantile forms, juvenile NCL exhibited normal metabolic profiles. In one patient disease progression was indicated by reduced NAA and Cr in gray matter in a follow-up study after four years. The present findings in NCL are consistent with irreversible and generalized neuroaxonal loss as well as alterations of white matter glia similar to those found in leukodystrophies. The severity of metabolic disturbances correlates with clinical symptoms and decreasing age of onset.

Aspartic Acid↗
PubMed1996

Etiology of the acrodermatitis chronica atrophicans lesion in Lyme disease.

Spirochete diversity in acrodermatitis chronica atrophicans lesions in a closely defined central European site was compared to that in the local vector population, in human erythema migrans lesions, and in cerebrospinal fluid by amplifying and sequencing a segment of the gene of outer surface protein A directly from sampled tissues. Borrelia garinii, Borrelia afzelii, and Borrelia burgdorferi acutely infect human skin and invade internal tissues. Only B. afzelii, however, is associated with acrodermatitis chronica atrophicans lesions, persisting chronically where the skin has atrophied.

Acrodermatitis↗
PubMed1996

Lyme neuroborreliosis in children.

Children are more likely than adults to be bitten by ticks and thus more likely to be infected by Borrelia burgdorferi. In a serosurvey the infection rate measured by immunoglobulin G (IgG) antibodies was 2.6%. In a prospective hospital-based multicentre study 169 children with Lyme neuroborreliosis were examined; the infection was diagnosed by detection of specific immunoglobulin M (IgM) antibodies in the cerebrospinal fluid (CSF) using an IgM capture ELISA. The yearly incidence of Lyme neuroborreliosis was 5.8 cases per 100,000 children aged 1-13. Facial palsy and lymphocytic meningitis account for nearly 90% of all cases with neuroborreliosis indicating striking differences in the clinical spectrum between children and adults. Lyme borreliosis proves to be the most frequently verifiable cause of acute peripheral facial palsy in children, causing every second case of this disorder in the summer and autumn. In cases of facial palsy, nearly all patients with a positive history of tick bite or erythema migrans in the head and neck region show ipsilateral subsequent facial nerve palsy, suggesting a direct invasion via the affected nerve by Borrelia burgdorferi. Lyme borreliosis is the third most frequent cause of lymphocytic meningitis in childhood. Inflammatory changes of the cerebrospinal fluid along with the presence of specific antibodies are mandatory for the diagnosis of Lyme neuroborreliosis. High-dose intravenous penicillin G as well as third-generation cephalosporins prove to be effective in paediatric Lyme neuroborreliosis.

Anti-Bacterial Agents↗
PubMed1995

Evaluation of the polymerase chain reaction for the detection of Borrelia burgdorferi in cerebrospinal fluid of children with acute peripheral facial palsy.

UNLABELLED: Neuroborreliosis occasionally represents a diagnostic problem, especially in the early stage of the infection. The polymerase chain reaction (PCR) offers an attractive alternative to antibody testing. The aim of our study was to investigate the diagnostic potential of PCR in comparison to antibody tests in CSF of children with facial palsy. In contrast to other manifestations of neuroborreliosis, facial palsy is a well-defined clinical entity in which CSF findings allow an early distinction according to aetiology. The study included 17 children with neuroborreliosis, defined by the detection of specific IgM antibodies in CSF, and 20 children with facial palsy of unknown cause. Primers used for the nested PCR were generated from conserved sequences of the OspA-gene. Most of the cases in both subgroups have been examined within a few days after the onset of the paresis. Only in 2 out of 17 cases with neuroborreliosis could specific DNA be amplified. The PCR gave negative results in all cases of the control group. CONCLUSION: The IgM capture ELISA is superior to PCR to support the clinical diagnosis of neuroborreliosis.

Acute Disease↗
PubMed1995

Male Rett variant.

Seven cases of male Rett-like syndrome have been reported in the literature, so far. Another case of a 7-year-old-boy is presented who shows the phenotype of classical Rett syndrome.

Brain↗
PubMed1995

Cerebral proton magnetic resonance spectroscopy in Rett syndrome.

Combined MRI/MRS studies were performed in 9 girls with Rett syndrome of different ages. NAA, as marker of neuronal tissue, was found to decrease with increasing age. There was no evidence for a defective energy metabolism. The data point towards a probably secondary degenerative process in the pathogenesis of Rett syndrome.

Adolescent↗
PubMed1995

Nondifferentiation between Lyme disease spirochetes from vector ticks and human cerebrospinal fluid.

To determine whether Lyme disease neuropathogenesis may result from infection by a particular segment of the locally extant population of spirochetes, genetic markers of spirochetes found in cerebrospinal fluid (CSF) of 12 pediatric patients were compared with those in spirochetes from 40 vector ticks sampled in the vicinity of their homes. The primary structure of the outer surface protein A served as the marker of variation; a fragment of the corresponding gene was amplified by nested polymerase chain reaction and the products sequenced. Tick-derived variants clustered in seven distinct categories, of which four were present in CSF. One of the CSF variants differed from any found in ticks. Coinfection by different spirochete variants was infrequent in ticks and absent in human samples. Spirochetal neuropathology in children in our study site does not correlate with a particular segment of the tickborne pathogens present in nature.

Amino Acid Sequence↗
PubMed1995

Hemimegalencephaly: localized proton magnetic resonance spectroscopy in vivo.

Two children with hemimegalencephaly were examined by magnetic resonance imaging (MRI) and localized proton MR spectroscopy (MRS). In both cases, structural changes in the enlarged hemisphere included pachy- or polymicrogyria and gliosis of white matter. Associated metabolic disturbances included a dramatic reduction of glutamate and N-acetylaspartate (NAA) in white matter. Less severe or no alterations were noted in cortical gray matter, basal ganglia, and cerebellum. The older child (13 years) showed increased myoinositol in both gray and white matter as well as markedly increased choline-containing compounds in gray matter. Both children also had mildly decreased NAA levels in the white matter of the contralateral hemisphere. The spectroscopic findings indicate loss of vital neuroaxonal tissue and glial cell proliferation. Metabolic disturbances were more pronounced in the older child. The normal-appearing hemisphere was mildly affected in both cases.

Brain↗