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Biomedical subjects

H G Lenard

Publications and source records attributed to H G Lenard.

At least 37 records · Page 2Linked to original sources
PubMed1998

A new leukoencephalopathy with bilateral anterior temporal lobe cysts.

We describe an identical syndrome of cystic leukoencephalopathy in three Turkish children, including two siblings. The neurological findings were noted within the first months of life and include severe intellectual impairment, motor retardation, and spasticity. Magnetic resonance imaging of the brain showed extensive cysts within the anterior temporal lobes, ventricular enlargement and white matter disease. The signal intensities of the cysts' content were identical to those of the cerebrospinal fluid. The patients' screening for known inborn errors of metabolism, especially those characterised by white matter involvement, did not reveal any abnormality. The clinical picture and the magnetic resonance imaging characteristics are unique diagnostic features of a new disease entity so far not described in the literature.

Child↗
PubMed1998

Complete remission of a diffuse pontine glioma.

A patient is described in whom a large diffuse glioma of the pons extending into the midbrain was diagnosed at the age of 2 years. Biopsy showed a fibrillary astrocytoma. After shunting of a hydrocephalus, the clinical symptoms abated without conventional therapy. Repeated MRI studies showed a continuous decrease of the tumour which was no longer visible when the patient was 6.6 years old. In reviews on spontaneous remissions of oncologic disorders we were unable to find a case of a biologically benign brain stem tumour. There is one isolated report on a similar case, though without histologic documentation.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Primitive neuroectodermal tumors of the cerebral hemispheres in two siblings with TP53 germline mutation.

AWe report on two siblings (brother and sister) who developed cerebral PNETs at the age of 5 years and 6 months, respectively. Both children were treated by operation followed by polychemotherapy. The brother also received cranio-spinal irradiation. Nevertheless, the children died about 12 months and 24 months post-operatively due to extensive cerebral tumor recurrences. Shortly after having lost both of her children, the mother developed an intra-abdominal tumor, which was resected and histologically diagnosed as ovarian carcinoma. Because of this unusual familial clustering of tumors and a positive history of brain tumors and other cancers in several maternal relatives, we analyzed DNA isolated from both PNETs and the ovarian carcinoma as well as constitutional (leukocyte) DNA from the whole family for mutation of the TP53 tumor suppressor gene. This analysis revealed that all tumors were homozygous for a missense mutation at codon 213 (CGA => TGG) resulting in an amino acid exchange from arginine to tryptophane. The same mutation was present in one TP53 allele in the constitutional DNA of the mother and the children, indicating that the mother had transmitted a TP53 germline mutation to both of her children. Analysis of loss of heterozygosity at microsatellite markers from 17p confirmed deletion of the paternal (wild-type) allele in both PNETs. Further investigation of the PNETs by comparative genomic hybridization revealed multiple chromosomal abnormalities. Interestingly, some genomic changes were common to both PNETs, while many others were not, a finding suggesting substantial genomic instability, probably as a consequence of p53 inactivation.

Adult↗
PubMed1997

Cerebral metabolic changes in biotinidase deficiency.

Clinical and metabolic changes in the central nervous system are described in a patient with biotinidase deficiency before and after biotin treatment. Lactate, pyruvate and 3-hydroxyisovaleric acid as metabolic disease markers were measured in blood, cerebrospinal fluid and brain tissue by biochemical analyses or localized magnetic resonance proton spectroscopy. The patient improved markedly with biotin treatment. Nevertheless, neurological sequelae and abnormal intracerebral lactate concentrations persisted despite normalized metabolic disease markers in extracerebral fluids. Therefore, localized in vivo measurements of intracerebral metabolites may be a valuable tool for elucidating the pathogenesis of biotinidase deficiency.

Amidohydrolases↗
PubMed1997

Motor performance and handedness in children with developmental language disorder.

Developmental language disorder (DLD) is diagnosed when there is a failure of normal language development in a child with normal nonverbal intelligence. The discussion about additional or causal deficits is controversial. In this study a computer-based motor performance series with a tapping, aiming and pegboard movement task and an additional paper-pencil handedness test were applied to a group of children with DLD of the phonologic-syntactic subtype and with normal nonverbal intelligence to describe the additional motor problems. Furthermore we examined whether our DLD children showed a different handedness. Tapping and pegboard with both hands were significantly impaired in our DLD children. Overall our DLD children did not show a different handedness than the control group.

Age Factors↗
PubMed1997

Typical pattern of the Kaufman-Assessment Battery in children with developmental language disorder.

In this study we used the Kaufman-Assessment Battery for children (K-ABC), which assumes a dichotomy of sequential versus simultaneous processing of intelligence, in order to describe the typical pattern of processing in 25 children with normal nonverbal intelligence and developmental language disorder (DLD) of the phonologic-syntactic subtype, a mixed receptive-expressive DLD with grammatical and phonologic deficits. The results of the K-ABC showed a significant deficit in auditory sequential processing, whereas simultaneous processing was normally performed.

Child Language↗
PubMed1996

Diffuse polymicrogyria associated with an unusual pattern of multiple congenital anomalies including turribrachycephaly and hypogenitalism.

A newborn male infant born to consanguineous parents was found to have diffuse polymicrogyria associated with an unusual pattern of congenital anomalies including microbrachycephaly, turricephaly, blepharophimosis, microstomia with maxillary retrusion and mandibular prognathism, micropenis with cryptorchidism, camptodactyly and adducted thumbs, and a progeroid appearance. The combination of manifestations in our patient represents a unique form of polymicrogyria with congenital anomalies, probably representing a new syndrome.

Abnormalities, Multiple↗
PubMed1996

Goldenhar, Möbius and hypoglossia-hypodactyly anomalies in a patient: syndrome or association?

UNLABELLED: The Möbius, Goldenhar and hypoglossia-hypodactyly anomalies are usually sporadic conditions with a recurrence risk of about 2%. The combination of Goldenhar and one or the two others is rare, whereas the concomitant occurrence of Möbius and hypoglossia-hypodactyly, and/or Poland, and/or Klippel-Feil anomaly is well known. Pathogenetically, vascular disruptions around the 4th embryonic week have been hypothesized. In vivo and pathological studies as well as animal models support this theory for all the above-mentioned combinations. Whether a preceding blastogenetic alteration is an influencing factor or a disorganization mutation, remains unclear. We describe a 3-year-old girl with bilateral anotia, epidermoid on the right eye, 6th and 7th nerve palsy, hypoglossia, left hypodactyly, and ventricular septal defect. CONCLUSION: We wish to emphasize the aetiological relevance of vascular disruptions in this previously unreported combination of Möbius, Goldenhar and hypoglossia-hypodactyly anomalies. The concurrence of anomalies in this patient represents an association and not a pleiotropic syndrome.

Abducens Nerve↗
PubMed1996

Fetal CNS damage after exposure to maternal trauma during pregnancy.

Nine case reports are presented to indicate the possible effects of maternal trauma on surviving fetuses. Previous reports have only addressed fatal consequences. Traumata occurred between gestational weeks 23 and 37. Seven mothers had motor-vehicle accidents (MVA), two had blunt abdominal traumata. Four mothers suffered severe injuries, such as cerebral contusion, fractures or placental abruption leading to emergency Cesarean section. Premature uterine contractions were observed in five mothers and hemorrhage in two. The nine children were born after 30 to 40 weeks of gestation. Seven had normal postpartal vital signs, one required resuscitation and one premature needed assisted ventilation. Clinical symptoms were variable: movement disorders (n = 3), hydrocephalus (n = 2), convulsions (n = 1), cerebral palsy (n = 1), and normal (n = 3). Follow-up ranged from 7 months to 5 years. Neuroimaging revealed periventricular leukomalacia (n = 2), localized vascular infarctions (n = 2), hemorrhage (n = 1), hydrocephalus (n = 2) and global damage (n = 1). The causative role of maternal accidents was extremely likely in one patient, and probable but unproved in the remaining cases.

Accidents, Traffic↗
PubMed1995

The syndrome of autosomal recessive pontocerebellar hypoplasia, microcephaly, and extrapyramidal dyskinesia (pontocerebellar hypoplasia type 2): compiled data from 10 pedigrees.

The syndrome of autosomal recessive pontocerebellar hypoplasia, microcephaly, severely impaired mental and motor development, and extrapyramidal dyskinesia is a distinct system degeneration, previously designated pontocerebellar hypoplasia type 2 (PCH-2). To further characterize its clinical and neuroimaging features, we compiled data from 10 nonrelated pedigrees. Six pedigrees were Dutch, two Swedish, and two German. All 16 patients showed an identical profile of virtually absent developmental milestones, early-onset severe chorea, and microcephaly together with pontocerebellar hypoplasia. Family distribution supports autosomal recessive transmission. The present data support the PCH-2 phenotype as a distinct neurogenetic entity.

Adolescent↗
PubMed1995

Papillon-Lefèvre syndrome--successful treatment with a combination of retinoid and concurrent systematic periodontal therapy: case reports.

Papillon-Lefevre syndrome is a rare autosomal-recessive congenital differentiation disorder; the external signs are hyperkeratosis of the palms and soles. Intraorally, the most salient manifestations are dystrophic periodontal problems that affect both the primary and permanent dentitions and frequently lead to premature tooth loss. Two children were treated with acitretin 0.5 mg/kg of body weight per day from November 1992 to November 1993, and another child since October 1993. Concurrently, the children received professional oral hygiene care (scaling, root planing, and curettage). The combination of retinoid therapy and periodontal treatment improved the dermatologic and periodontal conditions.

Acitretin↗
PubMed1994

Haemolytic anaemia in association with Escherichia coli O157 infection in two sisters.

Two sisters, 2 and 5 years of age, suffered from acute haemolytic anaemia occurring after gastroenteritis with Escherichia coli O157. One patient developed clinical signs of severe and acute intravascular haemolysis and sepsis. She received transfusion and antibiotic therapy. The second patient presented with mild to moderate haemolytic symptoms only. None of them developed renal impairment. In serum of both children, elevated titres of short-lived agglutinins were demonstrated in the indirect haemagglutination assay consisting of sheep erythrocytes coated with lipopolysaccharide from E. coli O157. By immunoblot analysis IgM antibodies against the O157 lipopolysaccharide were demonstrated in the acute phase sera but not in follow up sera taken 2 months after disease. On erythrocyte membranes, adsorption of microbial antigens was detected by use of a pool-immunoglobulin fluorescence test. The immunological status of both patients was normal. Complete recovery from haemolytic disease was observed without further therapy. Microbial antigens attached to the cell surface were assumed to be the pathophysiological cause of E. coli O157 associated haemolytic anaemia in two siblings.

Acute-Phase Reaction↗
PubMed1994

Intracranial germ cell tumors: a comprehensive update of the European data.

Intracranial germ cell tumors are rare tumor entities in childhood and adolescents. Extra- and intracranial germ cell tumors are identical in their histologic pattern and occur in preferential midline localizations such as the pineal and the suprasellar region. Germ cell neoplasms show increasing incidence rates over the last 30 years. The majority of intracranial germ cell neoplasms are germinomas. About 90% of the patients with pure germinomas can be salvaged by radiotherapy alone according to modern protocols. Non-germinomatous malignant CNS-germ cell tumors are considered to have a poor prognosis. In order to improve the survival of patients affected by these tumors different treatment approaches adding chemotherapy to conventional surgery and radiotherapy have been initiated by various study groups throughout the world. Due to the rarity of these neoplasms only a very limited number of patients has been enrolled in each study. In 1993 an international working group on these tumors was established by the International Society of Pediatric Oncology (SIOP).

Brain↗
PubMed1994

Multisystem triglyceride storage disorder without ichthyosis in two siblings.

A four-year-old boy presented with hepatomegaly, vacuolized granulocytes (Jordans' anomaly) and slightly progressive myopathy as signs of multisystem triglyceride storage disease. The nine-year-old sister of the patient also showed Jordans' anomaly and early fatigability, but no overt weakness. Biochemical analysis revealed normal values for carnitines, carnitine palmityl transferase in serum and striated muscle, and beta-oxidation enzymes in striated muscles. Distribution of non-membrane-bound lipids in granulocytes, fibroblasts, smooth muscle cells and striated muscle was compatible with Chanarin-Dorfman syndrome. In contrast to Chanarin-Dorfman syndrome, our patients lacked congenital ichthyosis.

Child↗
PubMed1992

Magnetoelectrical stimulation of motor cortex in children with motor disturbances.

Transcranial magnetoelectrical stimulation (TMS) is now widely used as a diagnostic tool in adults. In this study we report our experiences with this technique in children with central motor disturbances. We used a Cadwell MES10 magnetoelectrical stimulator with a maximal magnetic field of 2 tesla. The stimulation procedure followed a standardized protocol, with the patients being as relaxed as possible in order to avoid contamination of parameters with different preinnervational levels. Stimulation data were compared to a data base obtained in 58 normal children. The first group of patients consisted of 20 children aged from 7 months to 16 years with hemiparesis of different etiologies. Neuroimaging data were correlated with the results of magnetoelectrical stimulation. In 13 patients a pathological pattern of TMS could be detected, and in 7 of these a corresponding lesion of the cortico-spinal tract was found in CT or MRI scans. In 7 children TMS was normal, in spite of a clear-cut lesion of the cortico-spinal tract in CT or MRI scans in 4 of them. The second group of patients consisted of 16 children with extrapyramidal disease, mostly of hereditary origin, such as DOPA-responsive dystonia or benign hereditary chorea. TMS showed a normal response pattern in this group. We discuss problems and possible pitfalls in TMS in childhood in evaluating the diagnostic value of TMS. At the moment the diagnostic usefulness of TMS in children with motor disturbances appears limited and calls for careful interpretation.

Adolescent↗
PubMed1992

Maturation of set-modulation of lower extremity EMG responses to postural perturbations.

To analyse the influence of different "postural sets" on stance stabilizing EMG responses in children, EMG responses to toe-up tilt perturbations were recorded in 70 children between the age of 9 months and 10 years, as well as in a control group of 10 adults under different postural set conditions, using either bilateral destabilization with eyes opened, eyes closed, or introducing additional minute upper extremity support. Recordings were also made with the children seated in front of the platform with the ankle joint angle being identical to that in the standing condition. Also recordings were made after unilateral destabilization in bilateral lower leg muscles, to determine if there is a generalization of EMG response patterns to the mechanically not disturbed side. Across all age-groups the principal modulation of EMG response changes according to postural conditions was identical. Long latency (LL) EMG responses were down-regulated when additional upper extremity support was provided. LL-responses were abolished in the sitting condition. With unilateral destabilizations throughout all age-groups short latency responses were restricted to the perturbed side, whereas long latency responses could be obtained symmetrically. The proximal to distal gradient of recruitment of muscle groups, remained identical across all age-groups. The data indicate that the basic organizational principle of stance stabilizing EMG responses and their modification by postural sets remains invariant across development. This indicates that the involved organizational principles are present as soon as a child is able to stand upright and are not subject to further shaping by motor learning.

Child↗