Follow-up of optic pathway gliomas in children with neurofibromatosis type 1

Optic pathway gliomas (OPG) are found in about 15% of patients with neurofibromatosis Type 1 (NF-1). The natural history of OPG is not yet well documented. Treatment in cases with growing tumors is still controversial. Twenty-one patients with NF-1 and OPG, diagnosed over a 20-year period, and followed neuroradiologically and ophthalmologically for at least two years, were reevaluated. The diagnosis of OPG was made at a mean age of 7.1 years (range 0-14.5 years); six children were asymptomatic, 15 were symptomatic. The mean follow-up was 9.0 years (2.0-18.5 (years). In eight initially operated or biopsied patients (three optic nerve and five chiasmal gliomas) tumor regrowth was found in one patient without progression on subsequent follow-up. Improvement of visual acuity occurred in one child after operation of a large suprasellar tumor and deterioration in one patient after biopsy of a chiasmal glioma. The neuroradiological follow-up of the 13 not-operated and not-radiated patients (four optic nerve and nine chiasmal gliomas) was stable in 10, progressive in three, resulting in visual loss in one patient. In 11 children (52%) a second tumor outside the optic pathway was found at a mean age of 4.0 years after the diagnosis of an OPG. Until now they are mostly asymptomatic. Second site tumors were operated in two children because of rapid tumor growth, one child died of a brainstem tumor. OPG are a frequent complication in children with NF-1, appearing within the first decade.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of halothane anesthesia on cerebral blood flow velocity in children]

The effects of halothane on the cerebral circulation were studied in 23 children during general anaesthesia. Blood flow velocity in one middle cerebral artery was recorded continuously by transcranial Doppler sonography. Furthermore arterial blood pressure, pulse rate, endtidal CO2partial pressure and endtidal halothane concentration were recorded. Mean flow velocities/mean arterial blood pressures were 79 cm x s-1/65 mmHg; 86 cm x s-1/61 mmHg; 78 cm x s-1/54 mmHg and 67 cm x s-1/48 mmHg with 1; 1.5; 2 and 2.5 per cent endtidal halothane concentrations, respectively. Endtidal CO2-partial pressure and pulse rate remained constant throughout the study. The higher cerebral blood flow velocities seen with 1.5 per cent halothane compared with 1 per cent can be explained by an increase in cerebral blood flow. The lower cerebral blood flow velocities and arterial blood pressure with 2.5 per cent halothane compared with 1.5 per cent indicate impaired cerebral autoregulation. However, cerebral blood flow appeared to be sufficient even with low arterial blood pressures.

Congenital tetraplegia, respiratory insufficiency, and hypoplasia of medulla oblongata

A term infant with normal delivery presented with congenital tetraplegia and respiratory insufficiency just after birth. Magnetic resonance tomography on days 8 and 72 of life revealed an extreme thinning of the lower medulla oblongata. Endoscopy confirmed this and demonstrated the presence of vascular anomalies around the lesion which were not detectable by angiography. It is presumed that this is a malformation of the lower medulla oblongata.

Bioanalytics of nimodipine--an overview of methods

The analytical test procedures currently established for the determination of the dihydropyridine calcium antagonist nimodipine in biological fluids are presented. Method of choice which has been dominantly used in pharmacokinetic investigations and drug interaction studies is gas chromatography with electron-capture detection (GC-ECD) subsequent to simple toluene extraction. The limit of quantification of 0.1 ng/ml in plasma conveniently allows to follow concentration/time profiles in the nano/subnanogram per ml-range after therapeutic doses. If not restricted by its markedly higher limit of quantification of approx. 1-5 ng/ml, high-performance liquid chromatography with either UV- or amperometric detection may be an attractive alternative for therapeutic drug monitoring or compliance control. A combined approach of HPLC and GC--chiral stationary-phase HPLC with GC-MS as off-line detection mode--has proven adequate and efficient to obtain pharmacokinetic data for nimodipine enantiomers after administration of the racemic drug.

[EEG changes in type I and type II lissencephaly]

Lissencephaly syndromes are rare disturbances of the neuronal migration with agyria and/or pachygyria. Typical patterns in the EEG of 5 children with lissencephaly are presented. Rhythmic alpha- or beta-waves with high amplitudes of diffuse or fronto-precentral localisation are characteristic in type I lissencephaly. In type II lissencephaly initially theta- or delta-waves of somewhat lower amplitude are observed. Sharp and slow wave-complexes of very high amplitude are found more often in type I lissencephaly. They seem to correlate with the severity of the brain malformation and the epilepsy. In both types of lissencephaly the spatial organisation of the background activity and the sleep-wake differentiation are absent. The EEG of most type I lissencephalies show no reactivity to intravenous benzodiazepines. With increasing age the frequency of the background activity and of the high amplitude rhythmic waves decrease in type I and increase in type II lissencephaly. A complete dedifferentiation of the EEG tracings has been observed in the course of type I lissencephaly. Lissencephaly is diagnosed by imaging techniques. However, with a high probability lissencephaly can be suspected already by its EEG.

Effects of laryngoscopy and tracheal intubation on cerebral and systemic haemodynamics in children under different protocols of anaesthesia

The effects of laryngoscopy and tracheal intubation on cerebral and systemic haemodynamics were studied in 30 children. The objective was to identify conditions in which the alterations of cerebral and systemic haemodynamics were minimal. The children were intubated after muscular relaxation and following 10 min of mechanical ventilation with end-tidal halothane concentrations of 1.5%, 2.0% and 2.5%, respectively. With 1.5%, 2.0% and 2.5% end-tidal halothane, the mean flow velocity increased by 26%, 19% and 5%, the mean blood pressure by 14%, 10% and 1%, and the heart rate by 26%, 8% and 5% respectively after intubation. Adverse effects of laryngoscopy and tracheal intubation on cerebral haemodynamics in children can be avoided by adequate anaesthetic protocols.

[Acute spinal syndromes in children and adolescents]

23 children with acute spinal syndromes are presented. The clinical signs were caused by trauma in 11 patients, by extramedullary tumors in 6, by operations (coarctation of the aorta, scoliosis) in 4 and by encephalomyelitis in 2. Motor signs (flaccid paraplegia or paraparesis, monoplegia, bilateral weakness) and changes of reflex intensities were always observed. Most children presented with disturbances of sensory functions and micturition, some exhibited ataxia. In addition to the neurological signs, plain films of the spine were of diagnostic importance after trauma, for tumors myelography and/or computerized tomography were most useful. The unfavourable prognosis of posttraumatic paraplegia may be improved by early application of corticosteroids in very high doses. The value of GM1-ganglioside is controversial. In cases of external compression by tumors a decompression of the spinal cord is urgent. "Spinal cord monitoring" can be used intraoperatively in surgery of scoliosis and coarctation of the aorta to detect neurological complications early. Differential diagnosis and therapies of encephalomyelitis and Guillain-Barré-Syndrome are discussed.

[Lissencephalia syndromes]

Lissencephaly is in most cases a genetic anomaly of the brain development with agyria and/or pachygyria. It causes severe psychomotor retardation and epilepsy, which is often resistant to therapy. Some patients with type-I lissencephaly show cranial and facial dysmorphism and a deletion of chromosome 17p13.3 (Miller-Dieker syndrome). The isolated lissencephaly sequence occurs without these features. Patients with type-II lissencephaly present additional malformations of the posterior fossa and of the eyes (Walker-Warburg syndrome) and in some cases muscular dystrophy (cerebro-oculomuscular syndrome). Lissencephaly can be suspected with a high probability by its typical EEG. It is proved by imaging techniques. Therapeutic success is limited, the life expectancy is strongly reduced.

Intracranial blood flow velocities during seizures and generalized epileptic discharges

In 51 children with different types of epilepsy, blood flow velocities in the middle cerebral artery were recorded continuously by transcranial Doppler sonography during a standard electroencephalogram of 30 min duration. In 16 children 33 epileptic seizures were recorded. During tonic seizures, the mean flow velocity increased to a maximum of 133%-191% (median 160%) of the baseline values. Tonic-clonic seizures were also accompanied by a velocity increase. During absence seizures the mean flow velocity decreased to a minimum of 46%-82% (median 71%) of the baseline values. Changes in cerebral metabolism and arterial blood pressure in the presence of disturbed autoregulation are thought to be factors causing these alterations. No alteration of the flow velocities occurred in cases of petit-mal status, electrical status epilepticus and in 35 children with generalized epileptic discharges of up to 5 s duration without clinical manifestations.

Conservation of the prohormone convertase gene family in metazoa: analysis of cDNAs encoding a PC3-like protein from hydra

A subclass of proteolytic enzymes that correctly cleave precursor proteins at paired basic residues and are structurally related to the bacterial subtilisins has recently been identified. In yeast, a single membrane-bound proteolytic processing enzyme encoded by the kex2 gene has been found, whereas in higher vertebrates cDNAs encoding four distinct enzymes (PC2, PC3, furin, and PACE 4) have been identified. Like kex2, furin (also known as PACE) contains a hydrophobic transmembrane domain, but PC2, PC3, and PACE 4 lack this feature. All five enzymes exhibit striking similarities in their catalytic domains, and this suggests that they have arisen from a common ancestral subtilisin-like gene. We report here the identification of cDNAs encoding a protein that is similar in structure to PC3 from a simple metazoan, Hydra vulgaris (formerly Hydra attenuata). cDNAs encoding two isoforms of this PC3-like enzyme were obtained that differ only in their carboxyl-terminal sequences, probably due to alternative splicing of a common pre-mRNA. Neither form contains a transmembrane domain. Predicted amino acid sequence comparisons revealed that the hydra PC3-like enzyme is 55.4% and 56.7% identical in the catalytic domain to mouse PC3 and human furin, respectively. RNA blot analyses revealed that the PC3-like RNA is expressed predominantly in the hydra body column and not in the head region, although the hydra head contains a high density of nerve cells, which synthesize a variety of neuropeptides. For this reason, we suspect that another proprotein cleavage enzyme isoform may be expressed in head nerve cells. The isolation of a PC3-like cDNA from hydra is consistent with the presence of neuroendocrine cells and indicates that the PC/furin gene family has been well conserved in all metazoa. A simplified nomenclature for the group of mammalian processing proteases is proposed.

Abnormal cerebral hemodynamics during attacks of alternating hemiplegia

Frequent episodes of bilateral weakness and apathy, followed later by hemiplegia of alternating sides were observed in a now 32-month-old girl. Transcranial Doppler ultrasonography showed reduced flow velocities in the middle cerebral artery of the affected side during a hemiplegic attack and increased flow velocities at different sites of the basilar artery during a bilateral episode. These abnormal cerebral hemodynamics appear to indicate that alternating hemiplegia and some forms of migraine have a similar pathophysiology.

[Cerebral Doppler measurements in risk newborn infants do not have a prognostic value]

PROBLEM

The prognostic value of cerebral doppler for the neonatal and the developmental prognosis was studied.

METHODS

A prospective longitudinal study on 175 newborns at risk was performed. The blood flow velocities were recorded transcranially in the middle cerebral, posterior cerebral and internal carotid artery on day 1, 3-5 and 8-10 of life. Neonatal mortality and cerebral sonography gave the criteria for neonatal prognosis. Developmental prognosis was determined at a corrected age of 9 months by neurological examination and Griffth's test.

RESULTS

In 60 neonates abnormal flow velocities were obtained at least at one recording. Ultrasound revealed cerebral hemorrhage in 20, hypoxic-ischemic encephalopathy in 5 children. 14 infants died during the neonatal period, 5 in the following months. Premature babies with birth weights below 1501 g and abnormal flow velocities presented more cerebral hemorrhages and deaths than those with normal flow velocities. At the age of 9 months a slight handicap was observed in 10, a severe handicap in 6 of the surviving 156 infants. The majority of infants with abnormal neonatal doppler-recording had a normal neurodevelopmental status.

CONSEQUENCE

Cerebral doppler seems to be of little value to determine the prognosis of newborns at risk.

[Children of drug-dependent mothers--personal experiences and review of the literature]

The increasing incidence of drug abuse in central Europe leads to a growing number of children with intrauterine drug exposure. During pregnancy various risks affect these children. Postnatally severe symptoms of withdrawal are observed frequently. The psychosocial development is endangered. Between 1986 and 1990 30 drug dependent women attended the obstetric department of the University Hospital Basel during pregnancy. The data of 21 children born to mothers drug dependent at birth were evaluated. 11 children were born in 1990. 12 mothers received Methadon, 10 were polydrug abusers. Positive serology was found for hepatitis in 18, for HIV-infection in 9 women. 6 babies were premature, 8 were small for gestational age. 20 newborns presented withdrawal symptoms which required a mean hospitalization time of 45 days. Tonic and/or clonic seizures were observed in 6 neonates. In 9 other children some symptoms were suspicious of seizures. EEG recordings were pathological in 10 of 12 infants. For the control of withdrawal symptoms 16 children received pharmacological treatment for a mean duration of 61 days. Neurodevelopmental examinations were performed in 14 children at an average age of 22 months. Neurological findings were pathological in 2 children. 3 had mild, 2 had severe mental retardation, 5 presented with behavioural disturbances. Our data are compared with those of the literature. Therapeutic proposals for children of drug dependent mothers are presented. The impact of methadon programs on the exposed children is discussed.

[Successful multiple resuscitation in flecainide poisoning]

After a family quarrel a 37-year-old woman swallowed, with suicidal intent, a large number of flecainide tablets (exact amount unknown) together with alcohol. On admission to hospital some hours later her pupils were fully dilated, fixed and of irregular outline; she was unconscious and in cardiorespiratory failure. Nine hours after admission several episodes of ventricular fibrillation and asystole occurred, two of them lasting for 2 and 3 hours, respectively, before successful resuscitation (after defibrillation). The highest plasma flecainide level, between 3 and 10 hours after swallowing the drug, was 6160 ng/ml, i.e. six times the maximal therapeutic level. Under the influence of flecainide the ECG of the previously healthy woman had shown idioventricular rhythm with marked QRS widening and Q-T prolongation. The tachyarrhythmias, at times torsades de pointes, were successfully treated with high doses of lidocaine (4 g daily) after repeated defibrillations. As a late complication the patient went into acute left ventricular failure with pulmonary edema and pneumonia. There were no recognizable permanent sequelae on discharge 37 days after admission.

[Aspects of cerebral circulation in children]

Investigation of cerebral circulation represents an essential diagnostic adjunct to pediatric neurology. Doppler-sonography is presented as one of the diverse techniques to examine cerebral hemodynamics. The human cerebral circulation is controlled by autoregulatory mechanisms. Factors such as hematocrit, pulse, orthostasis and physical activity modulate the cerebral blood supply. The demand for blood depends essentially on arterial pCO2 but also on behavioural situations such as mental activity, effect of sensory stimuli or sleep. Bioelectric activity and perfusion of the central nervous system are closely linked. The cerebral perfusion in infants is characterized by a rapid increase in flow over the first couple of years to values exceeding those of adults. Disturbances of the cerebral perfusion are found in a variety of pediatric diseases. The patterns of perinatal brain damage depend on the maturity of the newborn. They are mainly sequels of impaired cerebral perfusion. In prematures periventricular leukomalacia and intracerebral hemorrhage are frequent whereas in infants at term cerebral edema and infarcts are more common. Acute hemiplegia in childhood can be of thromboembolic or vascular origin, however of etiologies different from those in adulthood. Prevention is the best treatment for disturbances of cerebral perfusion in childhood. Continuous monitoring techniques and pharmacotherapy need further clinical investigation.

Non calcific vasculopathy in the basal ganglia

Stripes of high echogenicity in the basal ganglia of infants have been rarely observed on cerebral ultrasound. These lesions, which appear to be due to a non calcific vasculopathy, are caused, in the majority of cases, by congenital infections and trisomy 13. We describe four infants with the characteristic ultrasonic appearance of this vasculopathy. Two children had cytomegalovirus (CMV) infection, one a human immunodeficiency virus (HIV) infection. The fourth child who presented a malformation of the skull and eye anomalies had no definitive diagnosis. Of the three surviving children one was developing normally. One had mild and one severe psychomotor retardation.

Cerebral blood flow velocities during orthostasis and physical exercise

The peak flow velocities in the middle cerebral artery were continuously recorded by transcranial Doppler sonography in 29 children. Arterial blood pressure and heart rates were measured every minute. The values observed during orthostasis and physical exercise were compared to baseline values obtained in the supine position. During orthostasis the velocities were, on average, reduced to 87%-94%, the minimal values being 75%-78% of the baseline values. The heart rate increased whereas blood pressure showed only minor alterations. Upon standing up the systolic peak flow velocity remained unchanged while the mean- and enddiastolic peak flow velocities decreased to 66% and 39% respectively. On average, the velocities increased to 103%-108% during physical exercise. Systolic blood pressure increased to the same extent, the heart rate even more. Continuous recording of cerebral blood flow velocities may be more useful than intermittent measurements of blood pressure to differentiate children with and without symptoms of orthostasis.

[Brain circulation in residual cerebral damage. A Doppler ultrasound study]

Transcranial Doppler recordings of flow velocities in 5 cerebral arteries were performed in children with cerebral palsy or with focal epileptic discharges. In 22 children with severe bilateral cerebral palsy as an average the flow velocities were 55% of the norm. In 8 of 10 children with spastic hemiplegia, the velocities were reduced at least in one artery of the affected side. 7 of 11 children with a mixed focus and 4 of 18 children with a pure epileptic focus in the EEG presented reduced velocities within the artery belonging to the focus. The results and other studies indicate a reduced cerebral blood flow in severe cerebral palsy with may be caused by vascular, metabolic, bioelectric or pharmacologic factors.

[Translocation trisomy 4q in 2 siblings as a sequela of paternal balanced reciprocal translocation: t(1;4)(q44;q31)]

In a sister and a brother with striking similarity of facial dysplasias, severe disturbance of expressive speech, and mild mental retardation a partial trisomy of the long arm of chromosome 4 was identified as cause of these anomalies. The partial trisomy 4q was due to a balanced translocation between the chromosomes 1 and 4 in the father of both children.

[An unusual "tumor-like finding" between the head of the pancreas and the duodenal wall]

A 48-year-old woman complained of right-sided upper abdominal pain and recurrent vomiting, and had lost 10 kg in 4 months. Ultrasound and computed tomography showed a solid, space-occupying lesion in the head of the pancreas, not separable from the duodenum. Despite thorough investigation the nature of the lesion remained obscure. Operation revealed a divided pancreas with stenosis of the accessory duct at the papilla. Histological examination showed pseudosarcomatous myofibroblastic proliferation within the duodenal wall in the vicinity of a duodenal wall cyst which had been destroyed by inflammation. In cases of divided pancreas it is the accessory duct which drains the main bulk of the pancreas, while the main duct carries little or no secretion; the stenosis of the accessory duct in this patient had therefore led to low-grade pancreatitis involving the head of the pancreas.

Origin of the left coronary artery from the right pulmonary artery and ventricular septal defect in a child of a mother with raised plasma phenylalanine concentrations throughout pregnancy

A child with anomalous origin of the left coronary artery from the right pulmonary artery, ventricular septal defect, fetal growth retardation, and facial abnormalities was born to a woman in whom plasma phenylalanine concentrations had been raised throughout pregnancy. The cardiac abnormalities were diagnosed by angiography when the child was eight months old. The anomalous coronary artery was imaged in a subsequent echocardiogram. Development retardation was caused by maternal phenylketonuria, which may also have been responsible for the development of the ventricular septal defect and the coronary anomaly. If dietary treatment of the mother had been started before pregnancy damage to the child might have been prevented.