PubMed Health⌕ Search

Biomedical subjects

G Blennow

Publications and source records attributed to G Blennow.

At least 37 records · Page 2Linked to original sources

Hyperthermia aggravates and hypothermia ameliorates epileptic brain damage.

The influence of hyperthermia and hypothermia on epileptic brain damage was studied in rats, in which status epilepticus was induced by flurothyl. Histopathological changes were examined by light microscopy after 1 or 7 days of recovery. Two series of animals were studied. In the first, short periods of seizures (20 and 25 min) were employed to examine whether moderate hyperthermia (39.5 degrees C) would aggravate epileptic brain damage, and a longer period (45 min) was used to investigate whether moderate hypothermia (32.5 degrees C) would ameliorate the damage. The second series investigated whether brief periods of status epilepticus (10 min) would cause brain damage if hyperthermia were high or excessive. For this series, animals with body temperatures of 37.0, 39.0, and 41.0 degrees C were studied. Data from normothermic animals (37.5 degrees C) confirmed previously described neuronal damage. Although hyperthermic animals failed to show increased damage in the CA1 sector, or in the hilar region of the dentate gyrus, they showed enhanced damage in the neocortex and globus pallidus (GP). In substantia nigra pars reticulata (SNPR) four out of five hyperthermic animals had bilateral infarcts after 20 min of status epilepticus, whereas no normothermic animal showed such damage. Hypothermia seemed to ameliorate epileptic brain damage in the neocortex (n.s.) and GP (P < 0.05) following status epilepticus for 45 min. Three out of seven hypothermic animals had mild SNPR involvement compared to severe infarction of the nucleus in five out of six normothermic animals (P < 0.05). Thus, hyperthermia aggravated and hypothermia ameliorated epileptic brain damage both in regions showing selective neuronal necrosis (neocortex) and in regions developing pan-necrosis (GP and SNPR). The second series displayed an unexpected result of excessive hyperthermia. Animals subjected to only 10 min of status epilepticus at a temperature of 41 degrees C showed not only neocortical lesions, but also moderate to extensive damage to the hippocampus (CA1, subiculum, and dentate gyrus). It is concluded that at high body and brain temperature, brief periods of status epilepticus can yield extensive brain damage, primarily affecting the hippocampus.

Animals↗

Withdrawal of antiepileptic medication in children. Correlation of cognitive function and plasma concentration--the multicentre 'Holmfrid' study.

Eighty-three patients with epilepsy and 83 matched controls completed 12 computerized cognitive tests while on antiepileptic drugs and six months later when they had been medication-free for three to four months. All patients had been seizure-free for more than one year and were on monotherapy with carbamazepine (CBZ, n = 56), valproate (VPA, n = 17), or phenytoin (PHT, n = 10). The tests and plasma concentration collection were done at noon. The mean peak plasma concentrations in the CBZ patients were as follows: 31% below 30 mumol/l, 48% between 30 and 42 mumol/l and 21% above 42 mumol/l. No difference in performance could be detected between the groups. One significant correlation between plasma concentration and test results was found. The mean VPA concentration was 625 mumol/l (S.D. 189). A tendency towards a weak negative correlation between test results and plasma concentration was present. The PHT patients' therapeutic range had a mean concentration of 32.0 mumol/l (S.D. 18.5). One significant correlation between a memory test and plasma concentration could be detected. Overall, the patients in the different antiepileptic groups performed less good than the control group and in a few cases the differences were statistically significant when compared either before or after withdrawal. A comparison of the changes after withdrawal showed improvement in the majority of tests, but these changes were also present in the matched control group.

Adolescent↗

Carbohydrate-deficient glycoprotein syndrome: clinical expression in adults with a new metabolic disease.

A new group of recessively inherited metabolic disorders affecting glycoprotein metabolism has been identified--the carbohydrate-deficient-glycoprotein (CDG) syndromes. Here the course and clinical expression of CDG syndrome type I in 13 patients who have passed the age of 15 years are described. All presented with early onset psychomotor retardation, in most cases combined with slight facial dysmorphic features, some degree of hepatic dysfunction, and in one case, pericardial effusion. About half of the patients had subcutaneous lipodystrophy and comatose or stroke-like episodes during childhood. After the age of 15 the disease was mainly characterised by neurological symptoms consisting of non-progressive ataxia associated with cerebellar hypoplasia, stable mental retardation, variable peripheral neuropathy, and strabismus. One third of the patients had generalised seizures, usually sporadic, and all had retinal pigmentary degeneration. In all cases there was more or less pronounced thoracic deformity and no female had passed puberty. Also, the oldest female showed premature aging. Severe internal organ symptoms, which are common in pediatric patients, were absent. All patients had highly raised serum concentrations of the biochemical marker carbohydrate-deficient transferrin, which can be used to verify the diagnosis. It is concluded that after childhood, CDG syndrome type I is a largely non-progressive disease compatible with a socially functioning but dependent lifestyle.

Adolescent↗

Sedatives and hypnotics in Stockholm: social factors and kinds of use.

OBJECTIVES: The aims of the study were (1) to estimate prevalence rates of current, regular, and long-term use of sedatives and hypnotics and the incidence of regular use in an urban population and (2) to study the association between such use of drugs and sociodemographic factors, symptoms of disease, and alcohol consumption. METHODS: Data on drug use in a random sample of 6217 adults in Stockholm County were analyzed with logistic regression. RESULTS: The prevalence rate for current use of sedatives or hypnotics was 12.8% among men and 18.6% among women; the rate for regular use was 3.7% among males and 4.7% among females. The odds ratio for current use increased with age and was higher among unemployed persons and disability pensioners, high consumers of alcohol, persons with an increased level of symptoms, and widows. More than 25% of the persons who had used sedatives or hypnotics during the previous 2 weeks were regular users 6 months later. For persons aged 25 through 64 years, the annual incidence rate was 1.8% among men and 2.7% among women. CONCLUSIONS: The comparatively low incidence and high prevalence of regular use implies that long-term use of sedatives and hypnotics is common.

Adolescent↗

Linkage of a locus for carbohydrate-deficient glycoprotein syndrome type I (CDG1) to chromosome 16p, and linkage disequilibrium to microsatellite marker D16S406.

Carbohydrate-deficient glycoprotein syndrome type I is a multisystem disease with early severe nervous system involvement. The disease, which is inherited as an autosomal recessive trait, is biochemically characterized by complex defects in the terminal carbohydrate residues of a number of serum glycoproteins. This can be most readily detected in transferrin. A whole genome scan was initiated in order to localize the gene (CDG1) with linkage techniques. We analyzed individuals from 25 CDG1 pedigrees with several highly polymorphic microsatellite markers and after exclusion of about 30% of the genome linkage was detected with markers located in chromosome region 16p. The lod score (Zmax) was above 8 (theta max = 0.00) for several markers in this region. In order to further localize the CDG1 gene, recombination and linkage disequilibrium analyses were performed. Recombination events in some pedigrees indicated that the CDG1 gene is located in a 13 cM interval between microsatellite markers D16S406 and D16S500. Furthermore, allelic association was shown for marker D16S406 indicating that the CDG1 gene is located close to this. No heterogeneity could be detected in the European family material tested by us. The positions of cytogenetically localized flanking markers suggest that the location of the CDG1 gene is in chromosome region 16p13.3-p13.12.

Alleles↗

Minor congenital malformations and mental characteristics during childhood: high-risk and normal-risk groups.

Among children with normal psychiatric risk, those born with (even minor) congenital malformations (CMs) evidenced significantly poorer attention persistence in early childhood, as well as greater anxiety-proneness, poorer interpersonal relational competency, and more mental disturbance at six years of age. No significant relationship between CMs and mental characteristics was found in children at heightened psychiatric risk.

Aggression↗

Seizures as the presenting symptom of brain tumors in children.

Epileptic seizures caused by tumors in children have been regarded as uncommon. We have studied 99 consecutive cases of brain tumors during the period 1980-1987. In 20 cases the tumor was localized to one of the hemipheres and 10 of the cases had seizures, in 9 as the only initial symptom. Details of the clinical picture and the course are presented. Delay from initial symptoms to correct diagnosis was considerable in 4 cases--more than six years. The factors mainly responsible for this delay were: initial EEG normal or soon normalized, misinterpretation of computerized tomography and seizure freedom with or without antiepileptic drug treatment. We conclude that regional slowing in the EEG is a common, although not obligatory, finding. Computerized tomography should be performed in all children with newly presented epilepsy of partial type, except for those with benign partial epilepsy with centro-temporal spikes.

Adolescent↗

Withdrawal of antiepileptic medication in children--effects on cognitive function: The Multicenter Holmfrid Study.

We present 100 children diagnosed with epilepsy who were seizure-free for more than 1 year and still on monotherapy of antiepileptic drugs (AEDs). We matched each child with a healthy classmate and performed neuropsychological testing and EEG before and after complete withdrawal of the AEDs. The withdrawal phase lasted 3 months, but the dose decrease was individualized for each patient. Three to 4 months after complete withdrawal of the drug all patients were reassessed. Patients with seizure relapse are excluded from the study. Seventeen patients are regarded as dropout, 11 because of seizure relapse and six because of protocol violation. The remaining 83 patients were treated with carbamazepine (n = 56), valproic acid (n = 17), or phenytoin (n = 10). Serum concentrations of the AEDs were measured using peak plasma levels that were taken immediately before or after psychological testing. We used neuropsychological tests to assess psychomotor function and "central" cognitive processing such as information processing or memory function. We found significant improvement attributable to drug withdrawal on only one of the cognitive tests, namely, psychomotor speed, suggesting that the impact of AED treatment on higher-order cognitive function is rather limited. In addition, we found group differences between the epilepsy group and the control group at baseline that persisted after drug withdrawal. Subsequent analysis showed some factors that may have contributed to these group differences. First, patients with a former diagnosis of absence seizures show lower scores both at baseline and after drug withdrawal. We may assume that the seizure propensity has not disappeared completely in these patients. Some evidence is found that phenytoin may have a different cognitive profile than carbamazepine, with more impairment on tests that measure motor and mental speed. Again, this impairment persists after drug withdrawal.

Adolescent↗

Sleep and wakefulness after treatment for craniopharyngioma in childhood; influence on the quality and maturation of sleep.

Craniopharyngiomas are situated in immediate vicinity of sleep regulating structures in the basal forebrain area, and the tumor and its treatment might influence the regulation of sleep and wakefulness. In 10 patients treated for craniopharyngioma nighttime sleep quality and daytime vigilance were examined with polygraphic sleep records and multiple sleep latency tests (MSLT). Two girls and 8 boys, 7.1-22.9 years of age, were studied after a follow-up time of 1.5-16.1 years postoperatively. The results were compared to those of 18 normal children. The regulation of the ultradian sleep rhythm was normal but the ability to maintain nighttime sleep was severely disturbed. The patients had an increased number of awakenings and spent long time awake during two recorded nights. Two patients had excessive daytime somnolence during this examination, one after severe sleep disturbance, the other without any known cause. The pattern of sleep and vigilance did not change in puberty in the expected fashion. The disturbances may well have an impact on the psychosocial situation of the patients.

Adolescent↗

Sleep and wakefulness in preadolescent children with deficits in attention, motor control and perception.

In 10 children with deficits in attention, motor control and perception (DAMP), the relation between daytime vigilance and night-time sleep quality was examined with polygraphic sleep recordings, multiple sleep latency tests and measurements of reaction times. Two girls and eight boys, 6-12 years of age were studied. Eighteen normal children served as controls. Normal sleep regulation and sleep quality was found, but the children with DAMP tolerated the recording procedure less well than the controls. Most patients did not suffer from increased daytime sleepiness, but at MSLT 3, patients had short sleep latencies as in daytime hypersomnolence. Reaction times were significantly longer among the patients than among the controls. It is proposed that the findings may be related to functional changes in the forebrain.

Attention Deficit Disorder with Hyperactivity↗

Congenital malformations and structural developmental anomalies in groups at high risk for psychosis.

OBJECTIVE: Early somatic developmental anomalies may be one expression of a genetic influence toward psychosis. The purpose of this study was to investigate whether higher rates of early developmental anomalies are associated with heightened genetic risk for psychosis. METHOD: Rates of congenital malformations and minor structural developmental anomalies were prospectively investigated in 84 high-risk offspring of women with histories of psychosis of nonorganic origin (schizophrenic, schizoaffective, affective, and other psychoses) and in 100 offspring of demographically similar control women with no history of psychosis. Data were collected by means of multiple physical examinations through the first 3-4 years of the offspring's lives. RESULTS: The rates of total congenital malformations were high, but the great majority of these malformations in both the index group and the control group represented minor physical aberrations. Rates of congenital malformations in the offspring of the index women (or any specific diagnostic subgroup of these women) were not different from those in the offspring of the control women. CONCLUSIONS: The inferred genetic risk for psychosis does not appear to be associated with greater rates of early somatic developmental anomalies, suggesting that early developmental anomalies do not represent an expression of genetic influence toward psychosis.

Comorbidity↗

Full-field electroretinograms in patients with the carbohydrate-deficient glycoprotein syndrome.

We examined five patients who had carbohydrate-deficient glycoprotein syndrome with full-field electroretinograms. Only two of the patients showed fundus changes typical for retinitis pigmentosa, whereas abnormal electroretinograms were seen in all patients. There was no recordable rod response; however, a delay in the cone b-wave implicit time was noted. All patients had nyctalopia. These observations suggest that patients with the carbohydrate-deficient glycoprotein syndrome have a progressive tapetoretinal degenerative disorder of the retinitis pigmentosa type with defined alterations in the electroretinogram.

Adolescent↗

Correction of non-24-hour sleep/wake cycle by melatonin in a blind retarded boy.

A 9-year-old, blind boy with severe mental retardation with a chronic sleep/wake disturbance had a circadian rhythm of 24.75 hours and an internal desynchronization of the endogenous rhythms. Treatment with oral melatonin given at 6 PM induced a regular sleep/wake pattern. Melatonin, in this patient, convincingly entrained the endogenous rhythm to the appropriate chronological 24-hour day.

Blindness↗

Neurological deviations in newborns at psychiatric high risk.

Neurological deviations on the third to fourth day of life were blindly assessed in 55 offspring of index women with histories of nonorganic psychoses and in 71 offspring of demographically similar control women with no history of psychosis. While the total index group did not differ from the total control group on rates of neurological deviation, the offspring of women with schizophrenia and cycloid psychosis showed more neurological deviations of a diverse nature than did their controls. The offspring of women with affective disorders had rates of deviation that were lower than those of controls and other index diagnostic groups. The differences observed were not sensitive to the narrowness of diagnostic criteria for schizophrenia and affective disorder.

Female↗

Importance of creatinine analyses of urine when screening for abused drugs.

We report here a simple method involving urine creatine measurements for testing authenticity and reducing false-negative results in urine testing for drugs of abuse. Urinary creatinine in consecutive patient samples (n = 176) ranged between 0.1 and 31.9 mmol/L (mean 9.8 +/- SD 6.2) and the osmolality in these urines ranged between 49 and 1183 mOsm/kg (mean 595 +/- SD 276). With other consecutive samples in which creatinine was (arbitrarily chosen) less than 4.3 mmol/L (n = 85), the correlation with osmolality was lower. In 10 randomly selected urine samples from different patients, all "clean" for all drugs of abuse in initial immunological drug testing with approved methodology (in which creatinine was less than 4.3 mmol/L and osmolality was less than 200 mOsm/kg), five patients turned out to be drug positive after a simple concentration by volume. In a formerly heavy smoker of cannabis, the excretion of cannabinoids and creatinine was monitored for 93 days. The substances showed very good correlation throughout this period (r = 0.93, P less than 0.001), whereas simple measurements of cannabinoid concentrations would have falsely indicated several relapses of cannabis abuse. Urine samples used in drug-abuse testing should be tested for creatinine; if creatinine is less than 4.0 mmol/L, negative results for drugs may not be valid.

Cannabinoids↗

Discontinuation of antiepileptic drugs in children who have outgrown epilepsy: effects on cognitive function.

Cognitive function is frequently impaired in children with epilepsy, compared with age-matched controls. It can be hard to evaluate the significance of various contributory factors. The effects of antiepileptic drugs may be studied in children who have outgrown their epilepsy but are still being treated. A multicenter study to assess various aspects of cognitive function in children with different forms of epilepsy, both during and after treatment with antiepileptic drugs, is currently under way. Definitive results are not yet available; interim analysis of the findings suggests that short-term memory is decreased in all subgroups of children being treated for epilepsy, compared to controls.

Adolescent↗