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Biomedical subjects

H Silfvenius

Publications and source records attributed to H Silfvenius.

At least 19 recordsLinked to original sources
PubMed2000

Overview: epilepsy surgery in developing countries.

Epilepsy surgery (ES) is addressed in relation to economic classifications of national resources and welfare in developing countries. A decade ago, ten developing countries conducted ES; now 26 such countries have reported results of ES. A number of international authorities define indicators of national economic welfare. Adopting the economic classification of the International Monetary Fund. we find that ES is nonexistent in 98% of African countries, 76% of Asian countries, 58% of European countries, 82% of Middle East countries, and in 86% of countries of the Western Hemisphere. The 1980-1990 global ES survey conducted by the International League Against Epilepsy identified ten developing countries reporting ES (DCRES): Brazil, China, Czechoslovakia, Hungary, Mexico, Poland, Taiwan, the U.S.S.R., Yugoslavia, and Viet Nam. The present survey based on the proceedings of the 19th-23rd International Epilepsy Congresses and Medline reports from 1991 to November 1999 revealed at least 26 (18.3%) DCRES of 142 developing countries: Argentina, Brazil, Chile, China, Colombia, Czech Republic, Egypt, Estonia, Hungary, India, Iran, Israel, Korea, Lithuania, Mexico, P.R.China, the U.S.S.R., Singapore, Slovenia, South Africa, South Korea, Taiwan, Turkey, Ukraine, Uruguay, and former Yugoslavia. National vital statistics expose the hardships of developing countries. The population ratio of developed countries to developing countries is approximately 1:5. The reverse per capita Gross Domestic Product ratio is 20:1. Great disparities exist in vital statistics, all to the disadvantage of the DCRES. The World Health Organization defines health-related sectors geographically, then divides developing countries into several subgroups. Disability caused by length of disease and years lived with disability can be quantified monetarily for epilepsy, and the total health expenditures of developed and developing countries can be compared. The DCRES are short of technology, and their ES teams must choose from an excess of surgical candidates, investigating with computed tomography, magnetic resonance imaging, noninvasive video-electroencephalography, and neuropsychology. The surgical outcomes achieved are similar to those in the developed world, but at a fractional cost. To internationalize ES, outcome, cost, and savings from care, evolution of assessment methodology is needed. Also needed is general support from the developed world.

Adolescent↗
PubMed1999

Proton magnetic resonance spectroscopy of brain biopsies from patients with intractable epilepsy.

In the present study metabolite concentrations were determined by proton magnetic resonance spectroscopy (MRS) in biopsies obtained from patients suffering intractable epilepsy from several different causes. Seven patients had gliosis, four had mild cortical dysplasia, three had tuberous sclerosis, two had astrocytomas, and one had a cavernous angioma. No significant differences were found in gliotic tissue in comparison with controls except for an increase in lactate. However, in the subgroup with tuberous sclerosis an increase was found in GABA and a dramatic decrease in N-acetyl aspartate (NAA). The most marked changes were found in the group with mild cortical dysplasia. There was a considerable decrease in NAA as well as large increases in GABA, alanine, tyrosine, acetate, inositol, glucose and lactate. The GABA content did not appear to correlate with antiepileptic therapy. Moreover, since all these patients required surgery, an elevated GABA level does not necessarily provide protection from seizures. The results indicate that use of proton MRS could become a useful presurgical predictor of underlying pathology.

Adolescent↗
PubMed1999

Cost-benefit of epilepsy surgery.

A cost-benefit study of Epilepsy Surgery (ES) evaluates the monetary consequences of the societal gain by reduced production loss. High direct cost of ES has been addressed by suggesting simpler diagnostics, preference for certain investigations, and weighing the direct cost against the postoperative savings. New MRI technology has simplified diagnostics and, currently, the surgical procedure is more accurate. A shortlasting procedure will reduce theater cost and hospitalization. Resective procedures achieve freedom from seizures in 45-90%. Postoperative worsening may be burdened by permanent morbidity, or may cause death. Re-operation, an extra direct cost, yields freedom from seizures in 45-50%, being thereby justified health economically. If ES stops seizures at the expense of impaired cognition, it is of limited help in restoring quality of life. In adults, surgery often is performed late, and the social status may have declined for the patient. Children with epilepsy and their families experience social restrictions difficult to normalize. A successful outcome unaccompanied by other improvement in life may turn into disappointment. Operated patients employed preoperatively continue to be so postoperatively, or maintain their employment which may also improve, an effect experienced even after a re-operation. But, a limited gain in employment after surgery has likewise been reported. Early surgery has a positive effect on education and occupation. The postoperative income of adults may increase significantly. Similarly, successful pediatric surgery is cost-effective for the child and the family. Using seizure free rate as effectiveness measure shows that ES is cheaper than AED treatment alone. The high cost for advanced diagnostics should be seen in a long-term perspective. The reduction in life long indirect cost after successful pediatric surgery has been evaluated.

Cost-Benefit Analysis↗
PubMed1997

Carotid angiography in conjunction with amytal testing of epilepsy patients.

Angiography is carried out as a basic part of the sodium amobarbital procedure in most institutions in order to predict the distribution of the amobarbital before the procedure itself is performed. This paper presents details of cerebral circulation to provide a framework that will help investigators who are not radiologists to interpret angiography results. The application of angiography specifically to the amobarbital procedure and the implications of different patterns of arterial filling for interpretation of speech and memory test results are discussed.

Amobarbital↗
PubMed1996

Cortical reorganisation of sensory, motor and language functions due to early cortical damage.

During evaluation of a 22-year-old man for epilepsy surgery it was demonstrated that reorganisation of sensory, motor and language functions had occurred. Restricted perinatal lesions in the left frontal opercular region and in the hand primary sensory area had resulted in severe partial epilepsy and minor neuropsychological deficits, but no neurological deficits. The dominance for language and handedness was shifted to the right hemisphere but some language representation was still found in the left hemisphere. Threshold electrical stimulation via subdurally placed cortical electrodes revealed reorganisation of the hand sensory area in the left hemisphere. Hand sensory responses were electrically evoked close to the opercular region where also face sensory responses were recorded. Some of the sensory responses were located in the frontal lobe in the premotor cortex. The locations of the sensory representation areas differed from those expected neuroanatomically. The cortical motor responses were located around the presumed location of the precentral gyrus. These findings are considered to represent a functional intra- and interhemispherical reorganisation of cortical areas as a result of early cortical lesions, anatomically close to the somatosensory and language areas. A possible mechanism discussed is reorganisation of the thalamocortical projections.

Adult↗
PubMed1996

Autism and epilepsy (and tuberous sclerosis?) in two pre-adolescent boys: neuropsychiatric aspects before and after epilepsy surgery.

We report on two pre-adolescent boys with a combination of severe seizure disorders and severe-moderate autism who underwent brain surgery for their epilepsy at the ages of 9 and 10 years, respectively. Both boys became seizure-free and initially improved dramatically with regard to autism symptoms. One of the boys continued to improve, but the other had a relapse to his pre-operative state in conjunction with his pubertal growth spurt. Several years after surgery, one of the boys remained much improved with respect to his autism. The other subject showed some improvement with respect to self-injury and aggression, and had slightly lower scores on screens for autism symptoms than in the year preceding epilepsy surgery. The histopathological examination of the brain tissue that was removed at surgery suggested a diagnosis of tuberous sclerosis in both cases.

Autistic Disorder↗
PubMed1995

Life satisfaction and sexuality in patients operated for epilepsy.

Changes in sexual behavior are often observed in patients with epilepsy. In order to investigate postoperative changes in sexuality and life satisfaction, operated and non-operated patients with epilepsy, as well as normal controls, were contacted for a survey. The questionnaire included 67 items concerning social background, life satisfaction, physical and psychological health, and sexuality (sexual desire, sexual contacts, sexual activity, etc). The results showed that patients with epilepsy do not rate overall life satisfaction much differently from neurologically normal control subjects. Specific questions regarding sexuality, revealed a lower sexual drive among the epilepsy patients compared with the controls. In most cases, there were no differences between the operated and the non-operated patients. Among the operated patients, the seizure-free group rated a higher level of life satisfaction and sexuality than the non-seizure free group.

Adult↗
PubMed1995

Latest advances in epilepsy surgery.

Recent advances in epilepsy surgery are a result of improved methods of assessment and diagnosis, a better understanding of seizures, the possibility of surgery at a younger age and the development of new surgical techniques. These factors have led to a wider selection of candidates for epilepsy surgery and shorter treatment trials with anti-epilepsy drugs before surgery is considered. The psychosocial indications for surgery, however, are often not examined thoroughly enough. Epilepsy surgery shows the best results following temporal lobe excision, with 68% of patients becoming seizure-free and 24% showing an improvement. Extra-temporal surgery results in 45% of patients seizure-free and 35% improved. The results of epilepsy surgery in children are similar to those of adults, with 67% of children becoming seizure-free and 21% showing improvement, following successful extensive cortical excision for non-inflammatory lesions. The beneficial psychosocial-economic effects of epilepsy surgery are, however, seldom documented and more research is needed into methods of quantifying, in broader perspectives, the outcome of surgery.

Adult↗
PubMed1993

Hemisphere inactivation and mood-state changes.

Mood-state changes were studied during a sodium Amytal testing procedure in epilepsy patients with unilateral temporal lobe foci. The results showed that inactivation of the left hemisphere, but not the right hemisphere, produced a negative mood state. This decline in mood was not specifically related to side of focus or sex. As expected, the inactivation of either hemisphere also lead to an impairment in memory performance. This impairment was somewhat worse during a left than a right hemisphere inactivation. Furthermore, patients with left hemisphere foci showed a lower memory performance than patients with a right-hemisphere lesion. These results suggest (a) a hemispheric specialization for emotion that underlie changes in mood and (b) a discrepancy between mood states at encoding (during inactivation) and retrieval (after inactivation).

Adult↗
PubMed1993

Biochemical correlates to cortical dysplasia, gliosis, and astrocytoma infiltration in human epileptogenic cortex.

The study provides detailed biochemical correlates to the common histopathological diagnoses in epilepsy. A dot immunobinding procedure was used for quantification of NSE, GFA, S-100, NCAM, NF 68 and NF 200. The material consisted of samples from 48 patients either selected for surgical treatment of partial epilepsy or for disorders not related to epilepsy. The histopathological diagnosis of the epileptic cases was: MCD (mild cortical dysplasia, microdysgenesis), gliosis, astrocytoma, ganglioglioma, oligodendroglioma and single cases. The concentration in non-epileptic white matter, in per cent of that in grey matter was: NSE, 85; GFA, 175; S-100, 117; NCAM, 43; NF 68,227 and NF 200, 173. The concentration of NSE as well as of GFA was close to normal in the specimens of the MCD and gliosis groups and of one subgroup of the astrocytomas. There was a striking inverse relationship of the GFA vs the NSE concentrations in the whole material. The concentrations of S-100 showed no such inverse relationship to NSE levels. In all the epileptic groups, total NCAM was lower than 50% of that of the non-epileptic group. The mean NF 68 and NF 200 concentration in the gliosis and astrocytoma groups was 75% of that of the non-epileptic group while the corresponding value for the MCD group was 50%. There was a positive correlation of immunochemically determined GFA and the histopathological gliosis score in the samples of epileptogenic cortex. There was no correlation between the concentration of GFA in the samples and the duration of epilepsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Co-variation of free amino acids in human epileptogenic cortex.

The concentration of free amino acids was measured in 41 surgically removed samples of human epileptogenic brain and in 7 specimens of non-epileptic brain tissue, removed during surgery for meningiomas, etc. The material was subdivided according to the neuropathological diagnosis: mild cortical dysplasia (MCD), gliosis astrocytoma infiltration and a histologically heterogeneous group. The non-tumoral epileptogenic samples had five times higher than normal concentration of ethanolamine and 50% elevated concentration of glycine. The concentration of other neurotransmitter amino acids did not differ markedly between epileptogenic and non-epileptic samples. The concentration of neurotransmitter amino acids showed a strong correlation with the enzyme neuron specific enolase (NSE) and were low in most samples with astrocytoma infiltration. On the other hand, tyrosine and leucine had higher concentrations in samples with lower NSE concentration. Factor analysis of the amino acids revealed four groups of covarying compounds in the brain samples, first, a neurotransmitter group, including aspartate, glutamate, GABA and phosphoethanolamine. Another group contained ethanolamine, glutamine, glycine and taurine. Factor analysis on corresponding extracellular amino acids showed two groups, the first being a "neurotransmitter" group, containing serine, taurine phosphoethanolamine and ethanolamine in addition to aspartate and glutamate. The other group consisted of asparagine, glycine, alanine, tyrosine, valine, phenylalanine, isoleucine and leucine.

Adolescent↗
PubMed1992

A compound score for estimating the influence of inattention and somnolence during the intracarotid amobarbital test.

Alterations in the level of consciousness may render the interpretation of the memory test results from the intracarotid amobarbital procedure difficult. The present study was designed to investigate the impact of inattention and somnolence on memory performance during the Amytal test. Nineteen consecutive patients undergoing the test were investigated. The memory test was constructed to comprise two consecutive parts with identical design, so as to make possible comparisons over time in the same patients. Reaction level and somnolence were continuously assessed during the procedure and a stimulus-task response test to evaluate the degree of attention was used. On the basis of these parameters a compound 'inattention score' was constructed. The results indicate that inattention and somnolence negatively influence memory performance and should be taken into account when evaluating the Amytal memory test results. In cases with poor memory results high inattention scores may speak in favour of preoperative hemisphere memory testing or a repeat injection with reduced Amytal dosage before deciding upon the extent of a planned resection. On the other hand, low inattention scores together with amnesia for the testing procedure may indicate that the memory test results can be relied on.

Adult↗
PubMed1992

Visual half-field testing of memory functions in patients considered for surgical treatment of intractable complex partial epilepsy.

The present research employed the visual half-field (VHF) technique to assess memory functions in normal subjects and in patients with unilateral temporal lobe epilepsy prior to surgery. Two studies were conducted. In Study 1, concrete and abstract words were presented to the left (LVF) or the right visual half field (RVF), and measures were made of response latencies, naming, free recall, and recognition. In Study 2, pictures depicting random shapes with low verbal association values were presented, and measures were made of latencies for identification and recognition of the shapes. Overall, the results showed a RVF advantage for words, but no lateralization for shapes. A selective hemisphere memory deficit was obtained for abstract words in patients with left temporal lobe lesions. Otherwise, no obvious lesion-related differences were found in the preoperative analyses. It is concluded that VHF testing of verbal information, but not abstract visuo-spatial information, is discriminative in assessing hemispheric functions in normal subjects and patients with temporal-lobe epileptic lesions.

Adult↗
PubMed1990

Sex steroids in human brain tumors and breast cancer.

The concentrations of three sex steroids, estradiol, progesterone and testosterone, were analyzed by radioimmunoassay after celite chromatography in brain tumor and breast cancer tissues. The concentrations in malignant gliomas and breast cancers showed interindividual variations, especially evident with regard to estradiol. High estradiol concentrations were recorded in two patients with malignant astrocytoma. The concentrations of 1.00 pg/mg and 3.32 pg/mg were 10 to 30 times as high as in normal female brain. In five of ten astrocytomas the estradiol concentration was higher than the lowest breast cancer value. The distribution of progesterone seemed more even, and the level was significantly lower in brain tumors and breast cancers as compared with female brain, perhaps indicating an increased metabolism. Testosterone levels were somewhat higher in brain tumors, as compared with breast cancers, but not different from values in brain tissue. There were no significant age or sex correlation or differences in the concentrations of steroids in the brain tumors. The results suggest that manipulation of sex steroid metabolism in malignant brain tumors can be of beneficial therapeutic value as has been shown for breast cancer and prostatic carcinoma.

Adolescent↗
PubMed1990

Pre- and postoperative rehabilitation related to epilepsy surgery.

A short review is presented of the mental impairment and personality deficits of persons with severe epilepsy and of their consequences, that require psychosocial and occupational rehabilitation, as well as of some aspects of health economics related to epilepsy surgery. It is concluded that detailed studies on the psychosocial outcome of epilepsy surgery are rather rare in the vast literature on epilepsy surgery, a situation that needs to be changed in order to promote better understanding of the therapeutic and palliative surgical treatment of epilepsy, to develop and broaden it, and to motivate more financial support from health authorities.

Activities of Daily Living↗