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Biomedical subjects

M L Friis

Publications and source records attributed to M L Friis.

At least 19 recordsLinked to original sources

Genetic and environmental factors in epilepsy: a population-based study of 11900 Danish twin pairs.

The contribution of genetic and environmental factors to the occurrence of epilepsy was examined in an unselected sample of twins recruited from the population-based Danish Twin Registry. Information on the occurrence of epilepsy in both members of a twin pair was obtained from 11900 pairs whose ages ranged from 12 to 41 years. Concordance rates, odds ratios and tetrachoric correlations were used to quantify the similarity of monozygotic (MZ) and dizygotic (DZ) twins. The sample was stratified by sex and separated into two age cohorts for analysis. Significantly higher probandwise concordance rates were found for MZ compared with DZ twins (0.37 and 0.08, P<0.01). Odds ratios and tetrachoric correlation showed similar pattern. An etiological model including additive genetic and individual specific environmental factors provided the best overall fit to the data, with 70 and 88% of the liability to develop epilepsy being accounted for by genetic factors in the younger and older cohorts, respectively. Individual specific environmental factors explained the remaining 30 and 12%, respectively. In conclusion, this study has confirmed the substantial impact, which genetic factors have in the etiology of epilepsy. The heritability of epilepsy is high and seems to increase with age.

Adolescent↗

Antiepileptic drug utilization: a Danish prescription database analysis.

OBJECTIVES: The purpose of the study was to use prescription data from a Danish database to analyse and evaluate antiepileptic drug (AED) utilization, and compare with other prevalence studies. METHODS: A Danish research database covering outpatient prescription data from a population of 471,873 persons was used. Prescription records on all patients prescribed AEDs during 1998 were retrieved. A cohort was extracted from the group of AED users. RESULTS: We identified 5426 AED users. A total of 3756 of the 5426 AED users were included in our cohort. Of the subjects in the cohort 74% were on monotherapy, 19% used two AEDs and only 7% used three or more AEDs. The eight most frequent regimens were all monotherapy: carbamazepine, oxcarbazepine, phenobarbital, valproic acid, lamotrigine, clonazepam, phenytoin and primidon in that order. The estimated crude 1-year prevalence of AED use was 0.77% for women and 0.83% for men (P<0.001), and it increased with age for both genders. CONCLUSIONS: The prescription pattern reported here is in accordance with the general guidelines for the treatment of epilepsy in Denmark, except for a surprisingly extensive use of phenobarbital. With specific reservations the figures appear to be reasonable estimates of the prevalence of epilepsy.

Adolescent↗

Recommendations on the clinical use of oxcarbazepine in the treatment of epilepsy: a consensus view.

Extensive clinical use and a series of clinical trials have shown that oxcarbazepine is a valuable antiepileptic drug for the treatment of adults and children with partial onset seizures both in initial monotherapy, for conversion to monotherapy and as adjunctive therapy. The clinically recommended titration scheme for all forms of therapy in adults is to start with 150 mg/day at night and to increase by 150 mg/day every second day until a target dose of 900-1200 mg/day is reached. If necessary, one can go faster and start with up to 600 mg/day and titrate with weekly increments of up to 600 mg/day. In children, treatment can be initiated with 8-10 mg/kg/day body weight in two to three divided doses. Dosage can be increased by 8-10 mg/kg/day in weekly increments if necessary for seizure control. Hyponatremia (serum sodium <125 mmol/l) can develop gradually during the first months of oxcarbazepine therapy in approximately 3% of patients with a previously normal serum sodium. However, there is no need to measure baseline serum sodium concentrations unless the patient has renal disease, is taking medication which may lower serum sodium levels (such as diuretics, oral contraceptives or nonsteroidal anti-inflammatory drugs) or--in rare cases--has clinical symptoms of hyponatremia. During oxcarbazepine maintenance therapy measurement of serum sodium levels should also be considered if medications known to decrease sodium levels are added or symptoms of hyponatremia develop. Oxcarbazepine does not appear to have any clinically notable effects on other safety parameters such as renal and liver function or haematological test results. In summary, oxcarbazepine is a safe and well tolerated antiepileptic drug for partial epilepsy.

Anticonvulsants↗

[Mortality in epilepsy. A review].

The overall risk of premature death in patients with epilepsy is two to three times that of the general population. The mortality risk is highest in patients with symptomatic epilepsy, but the mortality rate is also increased in patients with idiopathic epilepsy, indicating that epilepsy itself carries an increased risk of premature death. Cerebrovascular disease and primary brain tumours are common causes of death in patients with symptomatic epilepsy, while sudden unexplained death (SUDEP), accidents, suicide and status epilepticus are important causes of epilepsy related deaths. Prevention of accidents and suicide in patients with epilepsy and further knowledge on SUDEP is essential in order to reduce the mortality rate of epilepsy.

Accidents↗

[Extramammary Paget's disease interpreted as psoriasis].

We describe a case of extramammary Paget's disease (EMPD) in the lateral part of the breast of a woman with known psoriasis. The eczema was treated as psoriasis for three years. There were no macroscopic changes of the nipple or areola. Nodular swellings beneath the eczema proved to be infiltrating ductal carcinoma. The eczema showed the pattern of EMPD. A mastectomy was performed. Two foci of ductal carcinoma in situ were found in the mammary body and two foci of Paget's disease were found in the areola and nipple. Fourteen axillary lymph nodes were examined without signs of malignancy.

Aged↗

Distension-induced duodenal contractions vary with the phases of the canine interdigestive migrating motility complex.

BACKGROUND: The aim of the study was to evaluate whether the sensitivity for distension-induced contractions in the duodenum varied with the phases of the interdigestive migrating motility complex (MMC). METHODS: Four beagles (12-17 kg) with gastric fistulas were studied by means of perfused low-compliance manometry. A 2.5-cm-long balloon was placed in the third part of the duodenum. Side holes for pressure measurements were placed inside the balloon, 2cm proximal to the balloon, and in the antrum. Two-minute distensions with balloon pressures of 10 cmH2O were repeated in 10-min intervals during 17 MMCs. Twelve MMCs were also recorded without doing distensions. RESULTS: Balloon distension did not affect the duration of phase III and the MMC. In the beginning of phase I, distension did not significantly affect duodenal motility whereas distension induced contractile responses in late phase I, early phase II and late phase II (p < 0.05). The highest increase from the pre-distension to distension period was observed in early phase II (average 4 contractions min(-1)). However, considering the level of pre-distension contraction frequency, the fractional increase was by far the highest in late phase I. In phase III no difference was found between the periods before and during distension (15.8 +/- 0.7 versus 15.8 +/- 0.5 contractions min(-1)). The effect of balloon distension in phase IV was difficult to evaluate due to the inconsistent nature and sometimes rapidly decreasing activity in phase IV. Duodenal distension did not change frequency and amplitude of antral phase II contractions (p > 0.5). CONCLUSIONS: Duodenal balloon distension elicited ascending contractions in the canine duodenum in late phase I and in phase II. A refractory phase was demonstrated in the beginning of phase I while in phase III the frequency of contraction could not be increased further.

Animals↗

Valproate in the treatment of epilepsy in people with intellectual disability.

Valproate is a major broad-spectrum antiepileptic drug effective against many different types of epileptic seizures. Valproate is a first-line drug in the treatment of primary generalized seizures and syndromes, but it is also effective in other seizure and epilepsy types. The possible mechanisms of action and the pharmacokinetics of valproate are outlined. A limited number of studies on the efficacy and safety of valproate treatment in patients with West syndrome and Lennox-Gastaut syndrome have shown that even therapy-resistant people with intellectual disability can benefit from add-on valproate medication. In status epilepticus, valproate can be effective either intravenously, by gastric drip or following rectal administration. Patient tolerance towards valproate is generally good. The most serious adverse effect of valproate include hepatotoxicity and teratogenicity.

Anticonvulsants↗

Identification of mutations in the CACNL1A3 gene in 13 families of Scandinavian origin having hypokalemic periodic paralysis and evidence of a founder effect in Danish families.

Familial hypokalemic periodic paralysis (hypoPP) is an autosomal dominant disorder characterised by episodic attacks of paralysis of varying severity. Recently, linkage was found to markers in 1q31-32 and to the gene encoding the muscle DHP-sensitive calcium channel alpha 1-subunit (CACNL1A3). Subsequently, three mutations in this gene were identified in patients with hypoPP: Arg528His, Arg1239His and Arg1239Gly. In this study, two different mutations were found in the CACNL1A3 gene in 13 Scandinavian families, 10 of whom have the Arg528His mutation while 3 families have the Arg1239His. Furthermore, there is evidence of a founder effect in 8 of the 9 Danish hypoPP families investigated, consisting of haplotypes of microsatellite markers close to and within the CACNL1A3 gene and of the geographic origin of the families. For the first time, reduced penetrance in males with the Arg528His mutation was found in several cases.

Adolescent↗

Genetic mapping of a major susceptibility locus for juvenile myoclonic epilepsy on chromosome 15q.

The epilepsies are a group of disorders characterised by recurrent seizures caused by episodes of abnormal neuronal hyperexcitability involving the brain. Up to 60 million people are affected worldwide and genetic factors may contribute to the aetiology in up to 40% of patients. The most common human genetic epilepsies display a complex pattern of inheritance. These are categorised as idiopathic in the absence of detectable structural or metabolic abnormalities. Juvenile myoclonic epilepsy (JME) is a distinctive and common variety of familial idiopathic generalised epilepsy (IGE) with a prevalence of 0.5-1.0 per 1000 and a ratio of sibling risk to population prevalence (lambda(s)) of 42. The molecular genetic basis of these familial idiopathic epilepsies is entirely unknown, but a mutation in the gene CHRNA4, encoding the alpha4 subunit of the neuronal nicotinic acetylcholine receptor (nAChR), was recently identified in a rare Mendelian variety of idiopathic epilepsy. Chromosomal regions harbouring genes for nAChR subunits were therefore tested for linkage to the JME trait in 34 pedigrees. Significant evidence for linkage with heterogeneity was found to polymorphic loci encompassing the region in which the gene encoding the alpha7 subunit of nAChR (CHRNA7) maps on chromosome 15q14 (HLOD = 4.4 at alpha = 0.65; Z(all) = 2.94, P = 0.0005). This major locus contributes to genetic susceptibility to JME in a majority of the families studied.

Chromosome Mapping↗

[Progressive myoclonic epilepsy].

Progressive myoclonic epilepsy (PME) is a syndrome characterized by myoclonias, epilepsy, progressive dementia and other neurological deficits. PME may be caused by various, rare, incompletely elucidated genetic diseases, and is characterized by age at onset, duration, clinical and pathoanatomical abnormalities. There is ethnic and geographic variation in the frequency of the syndrome. The diseases are frequently autosomal recessive. Research in PME leads to a better understanding of the neurobiological processes of epilepsy. PME should be considered in cases of severe myoclonic epilepsy, progressive neurological disability and poor effect of antiepileptic treatment, and biopsies from skin, mucosa or muscle should be performed. Centralization of treatment of these rare diseases is recommended.

Adult↗

Controlled trial of lamotrigine (Lamictal) for treatment-resistant partial seizures.

The antiepileptic effect of lamotrigine (Lamictal) was assessed in a double-blind, placebo-controlled, crossover trial in 56 adult patients with refractory partial seizures. Lamotrigine or placebo was added to the patients' existing antiepileptic drugs (AEDs). The dose of lamotrigine varied from 75 to 400 mg daily. Thirty-eight patients completed the trial and 7 withdrew because of adverse experiences. There was a statistically significant reduction in seizure counts on lamotrigine compared with placebo for total seizures (30.3% reduction, 95% CI 8.4%, 47.0%), complex partial seizures (29.2% reduction, 95% CI 3.8%, 47.9%) and secondary generalised seizures (37.9%, CI 18.9%, 52.4%). The analysis of total seizure days showed a similar significant reduction during lamotrigine treatment for the same seizure categories. There was no statistically significant difference in reporting of adverse events between lamotrigine and placebo except for dizziness which was reported more frequently on lamotrigine than on placebo. There were no differences in abnormal haematological or biochemical findings between lamotrigine and placebo, and lamotrigine had no effect on plasma concentrations of concomitant AEDs.

Adolescent↗

Linkage analysis of juvenile myoclonic epilepsy and microsatellite loci spanning 61 cM of human chromosome 6p in 19 nuclear pedigrees provides no evidence for a susceptibility locus in this region.

Linkage analysis in separately ascertained families of probands with juvenile myoclonic epilepsy (JME) has previously provided evidence both for and against the existence of a locus (designated "EJM1"), on chromosome 6p, predisposing to a trait defined as either clinical JME, its associated electroencephalographic abnormality, or idiopathic generalized epilepsy. Linkage analysis was performed in 19 families in which a proband and at least one first- or two second-degree relatives have clinical JME. Family members were typed for seven highly polymorphic microsatellite markers on chromosome 6p: D6S260, D6S276, D6S291, D6S271, D6S465, D6S257, and D6S254. Pairwise and multipoint linkage analysis was carried out under the assumptions of autosomal dominant inheritance at 70% and 50% penetrance and autosomal recessive inheritance at 70% and 50% penetrance. No significant evidence in favor of linkage to the clinical trait of JME was obtained for any locus. The region formally excluded (LOD score < -2) by using multipoint analysis varies depending on the assumptions made concerning inheritance parameters and the proportion of linked families, alpha-that is, the degree of locus heterogeneity. Further analysis either classifying all unaffected individuals as unknown or excluding a subset of four families in which pyknoleptic absence seizures were present in one or more individuals did not alter these conclusions.

Adolescent↗

[Genetic aspects of epilepsy].

Accumulating evidence suggests a significant proportion of the forms of epilepsy to be genetically determined. Several epilepsy syndromes have been mapped on the human genome, though their molecular basis remains unknown. Technical advances in molecular biology now provide a basis for improving our understanding of the molecular mechanisms involved in genetically determined types of epilepsy Genetic mapping will improve the accuracy of genetic counselling. Improved insight into the molecular biology may help to elucidate the underlying epileptogenic mechanisms and pave the way for new developments in pharmacological control of epileptic seizures. Further advances in research on genetics and epilepsy will require national and international cooperation between epileptologists and geneticists in search of informative families for linkage analysis.

Chromosome Mapping↗

[Digital strangulation--released by the use of a dentist's drill].

A six year-old girl got her third right finger stuck into a padlock-fitting made of hardened steel. It was impossible to loosen the finger using the conventional methods of oil, soap, cooling, compression or wind-unwind technique. The fitting was split using a dentist's high speed drill and then easily removed leaving the finger uninjured.

Accidents, Home↗

[Neuropathy in adult metachromatic leukodystrophy].

Metachromatic leukodystrophy is a rare autosomal recessive disorder with deficient arylsulphatase A activity. Different forms occur according to the age at onset of symptoms. Adult forms generally present with presenile dementia and/or psychiatric symptoms. We report a case of a 45-year-old woman, without a family history of neuropsychiatric disorders, presenting with complaints of numbness and weakness of the lower limbs. No intellectual or behavioral disturbances were clinically detectable. Electrophysiological investigation was compatible with severe demyelinating neuropathy in upper and lower limbs. MRI of the brain showed multiple white matter lesions. Adult metachromatic leukodystrophy was diagnosed on the basis of low leucocyte arylsulfatase-A-activity and accumulation of metachromatic material in the sural nerve. Pseudo-deficiency was excluded by DNA analysis. This case indicates that adult metachromatic leukodystrophy should be considered in patients with symptoms and signs resembling multiple sclerosis with peripheral neuropathy and in patients with neuropathy of unknown etiology.

Brain Diseases↗

Inter-observer variation in the evaluation of neurological signs: patient-related factors.

The influence of patient-related factors on inter-observer variability in the evaluation of neurological signs was investigated. Two hundred and two consecutive unselected inpatients were examined by two senior neurologists who were unaware of the neurological case history. Eight signs were evaluated: anisocoria, jerky eye movements, facial palsy, difference in elbow extension force, abnormal finger-nose test, Barré sign, difference in knee jerk, and extensor plantar reflex. Agreement rates were calculated in order to compare the inter-observer variability with reference to the patients' sex, age, mode of admission, and diagnosis at discharge. Observed agreement rates for the eight examined signs only sporadically showed statistically significant differences between the chosen patient-related factors. In general, inter-observer variation does not appear to be influenced by the sex, age, mode of admission or diagnosis at discharge of the patients.

Adolescent↗