Search PubMed⌕ Search

Biomedical subjects

T Rasmussen

Publications and source records attributed to T Rasmussen.

At least 91 records · Page 5Linked to original sources
PubMed1991

Surgery for central, parietal and occipital epilepsy.

Patients with epileptogenic lesions that are more or less restricted to the central, parietal or occipital regions represent 14% of our total epilepsy surgery series and consisted of 322 patients at the end of 1980. Tumoral or major vascular lesions were present in 117 patients (37%), but this report is limited to the remaining 203 patients (63%) with non-tumoral epileptogenic lesions. The presumed etiology was birth trauma or anoxia in 25%, postnatal brain trauma in 25%, and unknown in 24%, miscellaneous lesions were present in 16%, post-inflammatory gliosis or multiple factors were present in the remaining 10%. Follow-up data of 2-51 years' duration (median 18 years) are available for 186 of these 203 patients. Sixty-three patients (34%) remain seizure-free. Forty-two patients (23%) have a marked reduction of seizures. The remaining 81 patients (44%) have a lesser reduction. The variation in clinical seizure patterns is considerably greater than in temporal lobe epilepsy. Focal sensorimotor phenomena are common at the onset, whether the seizures begin in the central region or further posterior. The success following cortical resection is equally gratifying and the failures just as distressing as in surgery for epilepsy, involving other brain regions.

Adult↗
PubMed1990

The clinical differentiation of seizures arising in the parasagittal and anterolaterodorsal frontal convexities.

The ictal clinical manifestations of 40 patients with frontal lobe epilepsy who became and remained seizure free after selective removal of the parasagittal or anterolaterodorsal convexities were studied. Seizures arising from the parasagittal region were characterized by a high incidence of somatosensory auras (60%) and by tonic and/or clonic motor behavior (100%) and never exhibited automatisms. Conversely, the anterolaterodorsal convexity group never showed somatosensory auras but often had warnings more typical of temporal lobe seizures, only displayed partial motor seizure activity in half the cases, and included a relatively high incidence of automatisms (30%). These clinical differences may be useful in the localization of frontal lobe epileptogenic foci. The manifestations of anterolaterodorsal convexity seizures may reflect frequent spread to the temporal lobe, whereas parasagittal convexity seizures often show initial ictal behavior, in keeping with seizure activity in that region. Early ictal unilateral head turning without other motor manifestations was seen in 3 of 10 patients in the parasagittal convexity group and in 9 of 30 patients in the anterolaterodorsal convexity group. In 11 of these 12 cases, the head turning was contralateral to the surgical removal.

Adolescent↗
PubMed1989

Cerebral hemispherectomy for seizures with hemiplegia.

The risk-benefit ratio of this functionally complete but anatomically subtotal hemispherectomy is strongly in favor of its more widespread and early use for the small group of unfortunate seizure patients who have maximal or near maximal hemiplegia and a complete or high-grade hemianopsia, and whose seizures constitute a significant handicap in regard to schooling and psychosocial development despite an adequate trial of appropriate antiepileptic medication. The earlier the "good" hemisphere and the upper brain are spared the nociferous effect of continual bombardment by wide-spread high-amplitude epileptiform discharges, the more effectively motor, sensory, intellectual, and psychosocial development can take place in the remainder of the nervous system.

Brain↗
PubMed1989

Physical and mechanical effects of cardioplegic injection on flow distribution and myocardial damage in hearts with normal coronary arteries.

The physical and mechanical effects of injecting crystalloid cardioplegic solution under various pressures and flows was studied (in canine hearts) to establish a safe method for administering it in the presence of normal coronary arteries. A constant pressure system (300 mm Hg = 15 psi) was maintained in the solution reservoir, and flows and pressures were varied with the use of cannulas of different inner diameters: 0.8, 1.35, 1.6, 2.3, 2.58, and 2.80 mm. Cardioplegia distribution was measured by 15 microns radioactive microspheres. Peak flow rate, total flow, and mean flow rate per infusion were measured by an inline electromagnetic flowmeter probe. Direct aortic root pressure, time to standstill, and myocardial temperatures were recorded by continuous monitoring. Cardiac isoenzymes were measured in the coronary sinus, peripheral blood, and directly in the myocardial tissue. Histologic changes in the left ventricle were examined by light microscopy. The results showed that the higher the flow and pressure, the shorter the prearrest period, the better the flow distribution, and the faster the myocardial temperature drop. Mean aortic root pressures higher than 110 mm Hg and peak flow rates greater than 1500 ml/min caused a higher incidence of mechanical-physical trauma to the vascular endothelium and the endocardium, but cellular protection was good. Low pressure (less than 30 mm Hg) and peak flows (less than 125 ml/min) showed a higher incidence of cellular (myocardial) ischemia, focal necrosis, and uneven flow distribution. An aortic root pressure of 61 +/- 5 mm Hg, a mean peak flow rate of 622 +/- 52 ml/min, and a total flow of 600 ml for the first injection seem to offer the best cellular protection with minimal physical injury to the endothelium and endocardium for a mean canine heart weight of 236 gm.

Animals↗
PubMed1989

Growth of fresh-frozen pulmonary allograft conduit in growing lambs.

To investigate the fate of cryopreserved pulmonary conduit allografts, an experimental model was used in lambs. The lambs underwent resection of the pulmonary trunk and valve to the level of the bifurcation of the pulmonary arteries and then were replaced by cryopreserved (CryoLife, Incorporated, Laboratories) pulmonary conduit allografts obtained from lambs of similar size. Lambs were operated on at 4 weeks of age and followed up with cardiac catheterization and cineangiography every 3 months for a period of 18 months. Lambs were electively sacrificed in the following order: two at 1 month, two at 3 months, one at 6 months, two at 12 months, and five at 18 months. To assess the structure of the conduit tissue, sections for light microscopy were obtained from the proximal, midportion, and distal ends of the conduit. While the lambs grew from a weight of 11.7 kg at the time of implant to more than 70 kg at 18 months, the diameter of the pulmonary conduit distended from 16 mm at the time of implant to 17.7, 19.1, 24.9, 34.3, and 33.7 mm at 1, 3, 6, 12, and 18 months, respectively. The length of the conduit also extended from an original inner length of 25 mm and an original outer length of 32 mm to the following dimensions: inner lengths of 27.9, 32.7, 38.8, 43.6, and 45.3 mm, respectively, at 1, 3, 6, 12, and 18 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Adrenergic effects on secretion of amylase from the rat salivary glands.

The present study was undertaken to investigate the effect of adrenergic agents on secretion of amylase from the salivary glands in vivo. Saliva was collected from the distal oesophagus in conscious rats. Adrenaline increased the concentration of amylase in saliva and serum significantly. The result of infusion of alpha- and beta-adrenergic antagonists as well as noradrenaline and isoproterenol showed that secretion of salivary amylase is predominantly mediated by stimulation of beta-adrenergic receptors, especially of the beta 1-subtype. Investigation of the isoenzyme pattern in saliva, pancreatic juice and serum demonstrated that the major component in serum is salivary amylase. This study has shown that beta-adrenergic agents stimulate secretion of amylase from the salivary glands in rats. Though the secretion is mainly exocrine small amounts of amylase is found in serum, which seems to originate from the salivary glands.

Amylases↗
PubMed1988

The Landau-Kleffner syndrome of acquired epileptic aphasia: unusual clinical outcome, surgical experience, and absence of encephalitis.

The syndrome of acquired verbal auditory agnosia in childhood with mutism and epileptic discharges has been described in over 100 cases. An encephalitic etiology has often been postulated but never proved. We report two patients with this syndrome who were treated surgically. Despite careful search, no pathologic evidence of encephalitis was found. One patient, with the typical course, had no seizures but striking positive correlation between epileptic discharge and language disorder; the second, after classic onset, developed intractable temporal lobe epilepsy, a previously unreported outcome of this syndrome. EEG discharges are generalized, bilateral, multifocal, or with shifting predominance but mainly temporal in 85% of reported cases, and unilateral, also predominantly temporal, in 15%. Language areas are preferentially involved. This syndrome has certain biologic features that resemble the benign epilepsies of childhood and may be the result of the unusual localization of the epileptic abnormality.

Adult↗
PubMed1987

Localizational concepts in epilepsy: past, present and future.

The clinical seizure pattern, particularly the initial phenomena, plus the EEG, when satisfactory recording of the seizure onset can be achieved, determine the primary localization of epileptic phenomena. The EEG has also demonstrated, by the presence of interictal epileptiform spike discharges, the presence of a second-order localization of epileptic phenomena, namely, the location and extent of cortex adjacent to the site of origin of the neuronal seizure discharge that is recruited into action in a clinical epileptic seizure. Experience with cortical resection in the treatment of focal epilepsy has demonstrated the importance of a third-order localization of epileptic phenomena, namely, how much of the potentially epileptogenic cortex must be excised in order to produce a satisfactory reduction of the seizure tendency.

Electroencephalography↗
PubMed1985

Adequacy of ascending aorta-descending aorta shunt during cross-clamping of the thoracic aorta for prevention of spinal cord injury.

The effectiveness of various sized shunts placed between the ascending and the descending aorta to prevent paraplegia in dogs with the thoracic aorta cross-clamped for 1 hour was tested. Three tapered shunts sizes were used with tip dimensions of 3.8, 5.2, and 6.3 mm inner diameter, with cross-sectional areas of 11.34, 21.23, and 33.18 mm2, respectively, and with an equal midportion diameter of 10 mm (3/8 inch). These shunts carried 40%, 60%, and 72% respectively, of baseline descending aortic flow during the cross-clamping period. Flow distribution was measured with radioactive microspheres in the spinal cord (gray and white matter) and kidneys. All dogs without shunts (Group I) developed paraplegia, severe proximal circulatory embarrassment, and severe ischemia of the spinal cord (mainly gray matter) that was followed by marked hyperemia persisting up to 24 hours following the experiment. Mortality was 33%. Only animals treated with large shunts (Groups III and IV) avoided paraplegia and postischemic injury. An effective shunt was characterized as carrying 60% or more of baseline descending aortic flow, having a cross-sectional area at its tip equal to or larger than 29% of the descending aorta, and equaling at least 54% of its diameter. Porportionately, the size of the tridodecylmethylamonium-heparin shunts being used in human beings (even the largest 9 mm inner diameter) is significantly inadequate to maintain distal flows and pressures for the prevention of spinal cord injury. Four clinical options are discussed.

Adrenal Glands↗
PubMed1984

Patient characteristics and age-dependent sub-populations in severe fibrocystic breast disease--the Hjørring project.

This study aimed at providing a detailed anamnestic, clinical, and mammographical characterization of 109 patients with fibrocystic breast disease, who were selected on the basis of pronounced mastodynia, prominent palpable structure and mammographical confirmation of the clinical diagnosis. Since these patients were selected for subsequent therapy, and most of them also underwent various hormonal investigations, accurate differential diagnosis was considered essential. Therefore, X-ray mammography was supplemented as required with adenography, galactography, and aspiration of cysts followed by aerography. Additionally, the results for most study variables were recorded by means of standardized scoring systems. On the basis of this characterization, three diagnostic sub-groups of fibrocystic disease could be distinguished: 20 patients with prominent glandular structure but no visible cysts (group A), 43 patients with prominent glandular structure as well as small (less than 1 cm) cysts (group B), and 46 patients with both small and large (greater than or equal to 1 cm) cysts. The three groups differ significantly in mean age (33.1 +/- 5.5 (SD), 39.2 +/- 4.9, and 43.7 +/- 4.6 years in groups A, B, and C, respectively). There was a significant trend towards increasing duration of breast complaints, and patients with a history of greater than 5 years account for 45, 65, and 74% in groups A, B, and C, respectively. Moreover, most of the study variables, viz. mastodynia, palpable structure, amount of glandular tissue, non-cystic nodularity, small cysts, duct ectasia, nipple discharge, and fibrosis, also tended to increase significantly in intensity and/or frequency from group A to B to C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Danazol treatment of severely symptomatic fibrocystic breast disease and long-term follow-up--the Hjørring project.

The purpose of the investigation was to study various aspects of danazol treatment in patients with fibrocystic breast disease and pronounced mastodynia. To qualify for inclusion, the patients in this study had to have a mammographically confirmed prominent glandular structure and/or severe cystic breast disease, associated with pronounced cyclical mastodynia lasting at least one week per menstrual cycle for more than 6 months. They also had to be premenopausal and not undergoing hormonal therapy. Of 109 patients with a mean age of 40 +/- 6.2 (SD) years, who completed 6 months' treatment with danazol, 65% had a pre-treatment history of more than 5 years. According to detailed mammographic characterization, only 18% of the patients had no visible cysts. Of the 82% with visible cysts, half presented with both small (less than 1 cm) and large cysts. The patients were treated in two consecutive groups, 55 patients receiving 400 mg a day and 54 patients 200 mg a day. The therapeutic response was similar following both dosages. Mastodynia responded rapidly and total elimination was noted in about 90% of cases. A marked decrease in prominence of palpable structure was observed in virtually all patients. Mammographically, a decrease in the amount of glandular tissue was observed. These changes during treatment were statistically highly significant (p less than 0.001), irrespective of dose or category of patient. Non-cystic nodularities gradually decreased in 85% and resolved completely in 58% of the cases, but the degree of resolution in the groups of patients with no or only small (less than 1 cm) visible cysts was significantly greater (p less than 0.02 or less) than in the group which also had large cysts and which included the most severe and intractable cases. The mammographical visualization of cysts, ductal system, and fibrous tissue increased initially due to the marked regression of obscuring glandular tissue. Thereafter, a decrease in the number and spread of small cysts was observed in a significant proportion of patients and in some cases a reduction in duct diameter could be demonstrated by means of galactography. Nipple discharge also decreased. The extent of fibrosis appeared to be unaffected by therapy. In the 46 patients with large cysts and, in most cases, a documented history of repeated cyst formation, danazol treatment was found to arrest the development of new cysts and to prevent recurrence for a considerable time thereafter.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1984

Treatment of recurrent cyclical mastodynia in patients with fibrocystic breast disease. A double-blind placebo-controlled study--the Hjørring project.

Thirty premenopausal women with recurrent, pronounced cyclical mastodynia associated with mammographically confirmed fibrocystic disease were studied. All patients had long-standing symptoms, had undergone one previous course of treatment with danazol, and were recruited during long-term follow-up after original treatment, when cyclical mastodynia had again reached similar severity as before the original treatment (mean interval between treatments 9.5 +/- 3.9 (SD) months). Fifteen patients each were randomly allocated to double-blind treatment with either danazol or placebo. During the first month, 2 capsules a day (each containing danazol 100 mg or placebo) were given, thereafter one capsule a day up to 6 months. Danazol caused a marked and sustained decrease in mastodynia, according to the clinician's assessment and according to each patient's self-rating on a visual analogue scale. The response to danazol was fairly uniform and statistically significant (p less than 0.005 or less), whereas the response to placebo was inconsistent and not statistically significant (p greater than 0.10). Danazol proved significantly more effective than placebo (p less than 0.05 or less). Changes in palpatory and/or mammographic findings were also found more consistently after danazol treatment than after placebo. During treatment, there was a modest weight increase, which was statistically significant in the danazol group (p less than 0.01) but not in the placebo group. A greater frequency in menstrual irregularities was observed in the danazol group than in the placebo group, but not to an extent that would have caused 'unblinding' of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Hemispherectomy for seizures revisited.

The serious, late complication of superficial cerebral hemosiderosis, which appears after several years in 1/4-1/3 of patients who have undergone hemispherectomy, has resulted in recent years in a considerable reluctance to carry out this operation despite the fact it has proved to be highly effective in patients with medically refractory seizures associated with hemiplegia. Preservation of a small portion of the hemisphere, usually the frontal or occipital pole, has proved to be effective in preventing this late complication, but at the cost of a significant reduction in the effectiveness of the operation in reducing the patients' seizure tendency. Preserving the frontal and occipital poles but disconnecting them from the rest of the brain, resulting in a functional complete but anatomical subtotal hemispherectomy, retains the therapeutic effectiveness of a complete hemispherectomy while still protecting adequately against the serious late postoperative complication of superficial cerebral hemosiderosis and its associated neurologic deterioration, hydrocephalus and sometimes death.

Adolescent↗
PubMed1983

Characteristics of a pure culture of frontal lobe epilepsy.

Forty patients with nontumoral epileptogenic lesions who have undergone cortical excision of portions of the frontal lobe for the relief of medically refractory focal epilepsy at the Montreal Neurological Institute during the period 1930-1971 have become and remained seizure free for a minimum period of 5 years (median follow-up 14 years). It seems logical to assume that, in these patients, the essential seizure-producing mechanisms were contained in the excised portions of the frontal lobe and such patients thus represent a pure culture of frontal lobe epilepsy. The clinical, radiological, EEG, surgical, and pathological findings were analyzed. The variability in the clinical pictures and EEG data gives ample testimony of the complex and varied patterns of spread of epileptiform discharges through the brain in patients with epileptiform lesions of the frontal lobe. The data presented also bear on two secondary localizational aspects of frontal lobe epilepsy: (a) how much cortex must be recruited into epileptiform discharge to produce recurring seizures, and (b) how much of the total potentially epileptogenic cortex must be removed to produce a satisfactory reduction of the seizure tendency. These data also emphasize the importance of improving the accuracy of our methods of evaluating these secondary and tertiary localizational aspects of epileptic phenomena.

Adolescent↗