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Biomedical subjects

M Lauritzen

Publications and source records attributed to M Lauritzen.

At least 91 records · Page 5Linked to original sources
PubMed1983

Changes in regional cerebral blood flow during the course of classic migraine attacks.

Regional cerebral blood flow (rCBF) following carotid arteriography was studied in thirteen patients with classic migraine. Using the 133xenon intraarterial injection method, rCBF was measured in 254 areas in one hemisphere. Nine patients developed a characteristic attack following arteriography and were examined by a series of rCBF studies, spaced by intervals of 5 to 10 minutes. A wave of reduced blood flow originating in the posterior part of the brain and progressing anteriorly was observed in eight of the nine patients. The oligemia advanced at a speed of 2 mm per minute over the hemisphere, progressing anteriorly but not crossing the rolandic or sylvian sulcus. Typically, the spreading oligemia reached the primary sensorimotor area after symptoms from that area had begun and persisted there long after the focal symptoms had disappeared. The observed time course suggests that the focal symptoms are not secondary to the oligemia. We suggest that focal symptoms and blood flow changes may be secondary to spreading depression of Leao.

Adult↗
PubMed1983

Regulation of regional cerebral blood flow during and between migraine attacks.

Cerebrovascular reactivity to voluntary hyperventilation, moderate hypertension, and physiological activation was studied in nine patients during induced migraine attacks and in four patients between their attacks. Regional cerebral blood flow was measured by the xenon 133 injection technique in 254 areas of one hemisphere. The partly hypoperfused hemisphere allowed for comparison of adjacent hypoperfused and normally perfused brain areas. During attacks the carbon dioxide reactivity was decreased to 2.8 +/- 0.8% per mm Hg in the oligemic regions compared with 5.8 +/- 0.8% per mm Hg in the normally perfused brain. Blood pressure autoregulation was normal in all brain regions. Regional blood flow increase in response to physiological activation was severely impaired in the hypoperfused brain areas, whereas neighboring normally perfused regions reacted normally. Confinement of the regulation abnormalities to the area of the oligemia supports our suggestion that the blood flow changes are caused by a change in local metabolism. Between attacks of migraine, the patients had normal regulation of brain circulation.

Blood Pressure↗
PubMed1982

Persistent oligemia of rat cerebral cortex in the wake of spreading depression.

Cerebral blood flow during and after spreading depression (SD) was studied in rat brain by quantitative autoradiography. The rise of cortical blood flow during SD was followed by 20 to 25% reduction below normal after SD, lasting at least an hour. Blood flow in th putamen, thalamus, and hippocampus did not change at any time during or after SD. Previous measurements of cerebral blood flow in humans showed that migraine attacks may be accompanied by wavelike spreading oligemia (Olesen et al, 1981). We speculate that the spreading oligemia of migraine may be a phenomenon physiologically related to the present finding of an oligemia after SD.

Animals↗
PubMed1982

Chlormezanone in the treatment of migraine attacks: a double blind comparison with diazepam and placebo.

One hundred and fifty patients treated for an acute migraine attack all received a standard regimen consisting of metoclopramide 10 mg i.m. and--20 min later--paracetamol 1 g orally. Simultaneous trial medication was given. This consisted of placebo, diazepam 5 mg as tablets, or chlormezanone 400 mg as capsules given in a double dummy fashion. A successful treatment result was defined as a decrease of two or three steps on a four-point verbal pain report scale, and no need for further treatment. Patients with severe pain (all three treatment groups together) showed significantly better treatment results (p less than 0.001) than patients with pain of medium severity. In the group with severe pain there was no significant difference between diazepam, chlormezanone or placebo. In the group with pain of medium severity there was a significant (p less than 0.01) effect of chlormezanone, but no significant effect of diazepam. Chlormezanone may possibly be a valuable addition to antiemetic and analgesic therapy of migraine attacks.

Acetaminophen↗
PubMed1982

The effects of sodium nitroprusside on cerebral blood flow and cerebral venous blood gases. I. Observations in awake man during and following moderate blood pressure reduction.

Cerebral blood flow (CBF) and cerebral venous blood gases were studied in seven patients before, during and after intravenous sodium nitroprusside infusion. The 133Xe intra-arterial injection method was used for the CBF measurements. A dose of sodium nitroprusside (mean 1.0 mg, mean infusion time 20 min), which reduced mean arterial blood pressure by a mean of 17%, resulted in a 13% decrease in CBF (P less than 0.05). Measurements obtained 5 and 20 min after termination of the sodium nitroprusside infusion showed no signs of a hyperaemic rebound effect. Arterial PCO2, metabolic rate of oxygen, arterio-venous oxygen difference and venous PO2 remained unchanged during and after infusion. It is concluded that sodium nitroprusside has a minor effect on cerebral haemodynamics, an effect that might be mediated by the sympathetic nervous system.

Adolescent↗
PubMed1981

Focal hyperemia followed by spreading oligemia and impaired activation of rCBF in classic migraine.

Regional cerebral blood flow (rCBF) was measured in 254 areas of a hemisphere with the xenon 133 intraarterial injection method. Six cases of classic migraine were followed from the normal state into the prodromal phase, and in 3 cases further into the headache phase. One patient with common migraine was similarly followed during his only classic attack. The attacks were initiated by focal hyperemia in 3 patients. During prodromes all patients displayed occipitoparietal rCBF reduction (oligemia), but in only 1 case did the reduction approach critical values. Oligemia gradually spread anteriorly in the course of 15 to 45 minutes. In 4 patients a global oligemia was observed. In 4 patients severe headache was present concomitantly with oligemia and with no sign of hyperemia or nonhomogeneous brain perfusion. The normal rCBF increase during cortical activity (hand movement, speech, and similar activities) was impaired in 6 patients. The results indicate that the vasospastic model of the migraine attack is too simplistic.

Adolescent↗
PubMed1981

Orbital bruits and retinal artery pressure in internal carotid artery occlusion.

Four patients are reported with orbital bruits. They had minor neurological deficits and all proved to have occlusion of the contralateral internal carotid artery. In three of the patients the retinal artery pressures were normal with no side to side difference, whereas pressure was slightly reduced on the occluded side in one patient. These observations give further evidence that an orbital bruit may indicate occlusion of the contralateral carotid artery with good collateral circulation.

Aged↗
PubMed1981

Regional cerebral blood flow during rest and skilled hand movements by xenon-133 inhalation and emission computerized tomography.

Regional cerebral blood flow (CBF) was studied in 16 normal adult volunteers during rest and in 10 the study was repeated during skilled hand movements. A fast-rotating ("dynamic"), single-photon emission computerized tomograph (ECT) with four detector heads was used. Xenon-133 was inhaled over a 1-min period at a concentration of 10 mCi/L. The arrival and washout of the radioisotope was recorded during four 1-min periods. Two slices, 2 cm thick, 7 and 12 cm above the orbitomeatal line were obtained in every study. CBF averaged 60 ml/100 g/min (SD +/- 11) in the lower slice and 51 ml/100 g/min (SD +/- 13) in the upper slice. A symmetric pattern comparing right to left sides was found in both slices. Finger tapping and writing with the right hand increased CBF in specific areas of the upper slice: in the contralateral hand area by 35 +/- 15% (p less than 0.025), and in the supplementary motor area on both sides by 34 +/- 15% (p less than 0.025).

Adult↗
PubMed1981

Relative reference values for clinical chemical and haematological quantities in 'healthy' elderly people.

A search of the literature revealed a paucity of data on reference values for clinical chemical and haematological quantities in reasonably 'healthy' ambulant persons above 65 years of age. On the basis of 90 papers, concerning 37 different types of quantities, the median values for men and for women at 30, 50, 65, and 80 years are calculated relative to the value in men at 30 years. This transformation reduces influences of analytical and demographic factors that have caused considerable systematic differences in the original data. The reference distribution is described as regards symmetry and the change in dispersion with age. The results are given in a table and show four types of changes with age: no significant variation, a fall, an increase or a maximum somewhere between 30 and 80 years; the type of change often depends on sex.

Adult↗
PubMed1981

EEG during attacks of common and classical migraine.

The Copenhagen acute headache clinic offered an opportunity to record EEG during migraine attacks in eleven patients with common migraine and ten patients with classical migraine. The median duration of the attacks was 9 h in common migraine. Three patients were studied during prodromes of classical migraine and seven in the early headache phase. The EEG was recorded in the resting state, during hyperventilation and during photic stimulation. No abnormalities were encountered in patients with common migraine nor in eight patients with classical migraine. In two patients with classical migraine mild abnormalities were seen during prodromes and in the early headache phase, but they were also present at a control EEG taken outside an attack. The present study indicates that migraine attacks are rarely associated with EEG abnormalities.

Adolescent↗
PubMed1980

Studies on the native forms of renin in the rat kidney.

This paper describes Sephadex G-100 chromatography of rat kidney extract containing various enzyme inhibitors. The high molecular weight renin (molecular weight above 50 000) constitutes about 50% of the total renin activity. Omission of the enzyme inhibitors yield solely low molecular weight renin. Upon rechromatography high molecular weight renin eluted in two peaks at lower molecular weight with a concomitant reduction of renin activity. Renin activity in the fractions from Sephadex G-100 chromatography was increased 70% by dialysis at acid as well as neutral pH through the whole molecular weight range. Cold storage of extract with low molecular weight increased renin activity about 25%. The results suggest that the fully active enzyme is not represented by the lower molecular weight forms of renin and direct connection between activation of renin and reduction of renin molecular size was not indicated.

Animals↗
PubMed1980

Eaton-Lambert syndrome and malignant thymoma.

Eaton-Lambert syndrome is most frequently associated with small-cell carcinoma of the lung. We describe the first case of this disorder in a patient with malignant thymoma. Guanidine treatment had no clinical or electrophysiologic effects.

Female↗