Published in 1985

Cerebral blood flow by xenon-133 washout: Tomographic/nontomographic metods compared

Kastrup, J., Olsen, T. S., Christensen, J., Sugiyama, H., Parving, H-H. & Lassen, N. A. 1985 I : Journal of Cerebral Blood Flow and Metabolism. s. 653-4 2 s.

Publikation: Forskning - peer reviewTidsskriftartikel

Originalsprog Engelsk
Tidsskrift Journal of Cerebral Blood Flow and Metabolism
Sider (fra-til) 653-4
Antal sider 2
ISSN 0271-678X
Status Udgivet - 1985

Focal increase of blood flow in the cerebral cortex of man during vestibular stimulation

Friberg, L., Olsen, T. S., Roland, P. E., Paulson, O. B. & Lassen, N. A. sep 1985 I : Brain. 108 ( Pt 3), s. 609-23 15 s.

Publikation: Forskning - peer reviewTidsskriftartikel

This study is an attempt to reveal projection areas for vestibular afferents to the human brain. Changes in regional cerebral blood flow (rCBF) were measured over 254 cortical regions during caloric vestibular stimulation with warm water (44 degrees C). rCBF was measured when the external auditory meatus was irrigated with water at body temperature as a control to vestibular stimulation. During vestibular stimulation there was only a single cortical area, located in the superior temporal region, which showed a consistent focal activation in the hemisphere contralateral to the stimulated side. On the rCBF display this area was located in the superior temporal region posterior to the auditory area, probably in the superior temporal gyrus. It is suggested that this area represents the primary projection area of the vestibular nerve and that it is the activation of this area during caloric stimulation that gives rise to the associated conscious vestibular sensation of vertigo.
Originalsprog Engelsk
Tidsskrift Brain
Udgivelsesdato sep 1985
Vol/bind 108 ( Pt 3)
Sider 609-23
Antal sider 15
ISSN 0006-8950
Status Udgivet

Published in 1984

The present study investigates the pathogenesis of focal cerebral hyperemia, its effect on brain tissue and discusses its pathophysiological and therapeutic importance in the light of interpreting severe hyperemia as a sign of arterial reopening probably due to embolic migration. Cerebral angiography, serial CT-scans and serial TC99 -scans were performed in a consecutive group of 73 patients with completed stroke all admitted to hospital within 3 days after stroke onset. When possible the regional cerebral blood flow (rCBF) was studied with the intracarotid Xe 133 injection method. Twenty-nine patients had evidence of middle cerebral artery (MCA) occlusion; rCBF was investigated in 24. Fourteen patients had either occlusion or severe internal carotid artery (ICA) stenosis; rCBF was not measured in these patients. Thirty patients had no angiographical evidence of MCA occlusion, ICA occlusion or severe ICA stenosis; rCBF was investigated in 24. Focal hyperemia was observed in 21 patients but exclusively in the group with evidence of MCA occlusion. Hence, these 21 patients are typical and representative for the group of patients with evidence of MCA occlusion. Hyperemia was found in infarcted as well as in non-infarcted tissue. Apparently, it is the severity of the initial ischemic episode and not the hyperemia that determines whether or not tissue necrosis develops. Interpreting severe hyperemia as a sign of arterial reopening and embolic migration (evidenced by partial reopening affecting only some MCA branches) reopening had occurred in about 1/3 of the patients with MCA occlusion before they were examined 1 to 4 days after stroke onset. Autopsy studies performed in 8 of the patients with MCA occlusion indicate that arterial reopening also takes place in many patients later on (7 of 8). According to this interpretation, hypothetical as it is, the changing position of the embolus is associated with partial or complete reperfusion leading to hyperemia in the initially ischemic brain tissue. The hemodynamic basis for appropriate therapy therefore may change from one day to the next in the acute state of stroke due to MCA occlusion.
Originalsprog Engelsk
Tidsskrift Stroke
Udgivelsesdato 1984
Vol/bind 15
Tidsskriftsnummer 3
Sider 458-68
Antal sider 11
ISSN 0039-2499
Status Udgivet

Thyroid stimulating immunoglobulins in Graves' disease with goitre growth, low thyroxine and increasing triiodothyronine during PTU treatment

Hegedüs, L., Hansen, J. M., Bech, K., Kampmann, J. P., Jensen, K., Andersen, E., Hansen, P., Karstrup, S. & Bliddal, H. dec. 1984 I : Acta Endocrinologica (Copenh). 107, 4, s. 482-8 7 s.

Publikation: Forskning - peer reviewTidsskriftartikel

In 50 consecutive patients with Graves' disease treated with PTU, 7 (group 1) developed increasing goitre in spite of unmeasurable TSH. Thyroid variables were compared with those from 10 controls with an ordinary response to PTU (group 2). Serum T4 decreased in group 1 from 246 +/- 47 nmol/l (mean +/- SD) to 40 +/- 9 nmol/l after 6 weeks of PTU treatment and continued to be below the normal range during the next 4 months. In group 2 serum T4 decreased from 190 +/- 35 to 88 +/- 47 nmol/l and stayed in the normal range. Serum T3 was normalized in both groups after 6 weeks but increased to values above the normal range in group 1 after that time. In spite of unmeasurable TSH during the 6 months of treatment in group 1, thyroid volume, determined ultrasonically, increased significantly from 60 +/- 29 to 93 +/- 68 ml (P less than 0.05), but was unaltered in group 2 about 25 ml. Thyroid stimulating antibodies (TSAb) measured by adenylate cyclase activation (normal below 109%) decreased in group 2 from 117 +/- 23 to 90 +/- 17% (P less than 0.01) (6 months of therapy), but increased significantly in group 1, from 201 +/- 47% to a maximum value of 234 +/- 69% (P less than 0.05). TSH binding inhibitory immunoglobulins (TBII) (given as per cent inhibition, normal below 26%) decreased in group 2 from 43 +/- 29 to 29 +/- 27% (P less than 0.05) but were unaltered high in group 1, 66 +/- 25% before therapy and 57 +/- 26% after 6 months of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
Originalsprog Engelsk
Tidsskrift Acta Endocrinologica (Copenh)
Vol/bind 107
Tidsskriftsnummer 4
Sider (fra-til) 482-8
Antal sider 7
ISSN 0001-5598
Status Udgivet - dec. 1984

Published in 1983

Blood flow and vascular reactivity in collaterally perfused brain tissue. Evidence of an ischemic penumbra in patients with acute stroke

Olsen, T. S., Larsen, B., Herning, M., Skriver, E. B. & Lassen, N. A. 1983 I : Stroke. 14, 3, s. 332-41 10 s.

Publikation: Forskning - peer reviewTidsskriftartikel

In a group of 48 patients with completed stroke, 8 patients had viable collaterally perfused brain tissue which was accessible for rCBF recordings with a two dimensional technique. All 8 had deep subcortical infarcts on CT-scan, and angiographic occlusion of the arteries normally supplying the infarcted territory. The brain tissue overlying the deep infarcts appeared normal on CT-scan and was supplied by collateral circulation. rCBF was measured in all within 72 hours after the stroke. The intra-carotid Xe-133 injection method and a 254 multidetector camera were used to study rCBF. Relatively ischemic low flow areas were a constant finding in the collaterally perfused tissue. In 6 of the patients, the collaterally perfused part of the brain had low flow values comparable to those of an "ischemic penumbra" (viable, but functionally depressed brain tissue due to inadequate perfusion). Autoregulation was impaired in all of the collaterally perfused areas while the CO2-response always was preserved. Steal phenomena were not seen. In the surrounding brain tissue, autoregulation was normal in 5 patients and impaired in 3 while the CO2-response seemed to be normal. The results confirm the experimental finding of an ischemic penumbra associated with acute cerebral infarcts and suggest that early restoration of the blood flow in acute stroke patients might improve recovery and prognosis in selected patients.
Originalsprog Engelsk
Tidsskrift Stroke
Udgivelsesdato 1983
Vol/bind 14
Tidsskriftsnummer 3
Sider 332-41
Antal sider 10
ISSN 0039-2499
Status Udgivet
Brain scintigraphy with Tc99-pertechnetate (Tc99-scan) was performed 4 times in 95 consecutive stroke patients: on average 5 days, 18 days, 103 days and 194 days after the stroke. The type (infarct, hematoma), size and localisation of the lesion was evaluated by CT-scan performed 3 times in all: on average 3 days, 18 days and 207 days after the stroke. The detection rate of Tc99-scan was 31% on day 5, 47% on day 18, 18% on day 103 and 9% on day 194. The detection rate was however highly dependent upon: (i) the localisation of the lesion, i.e. superficially localised lesions were nearly always identified (90%) while infarcts localised deep in the hemisphere were identified in only 20% of the patients; (ii) the size of the lesion, i.e. large deep infarcts were seen with a much higher frequency than small deep infarcts. The detection rate of the CT-scan was practically not dependent upon the time of investigation: 63% on day 3, 70% on day 18, 69% on day 207. The detection rate of the Tc99-scan and CT-scan was nearly identical for large superficially localised lesions 2-3 weeks after the stroke. In this period, however, CT-scan identified 30 deep infarcts. Only 12 of these were identified by Tc99-scan.
Originalsprog Engelsk
Tidsskrift Acta Neurologica Scandinavica
Vol/bind 67
Tidsskriftsnummer 4
Sider (fra-til) 229-34
Antal sider 6
ISSN 0001-6314
Status Udgivet - apr. 1983

Regulation of regional cerebral blood flow during and between migraine attacks

Lauritzen, M., Olsen, T. S., Lassen, N. A. & Paulson, O. B. nov 1983 I : Annals of Neurology. 14, 5, s. 569-72 4 s.

Publikation: Forskning - peer reviewTidsskriftartikel

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.
Originalsprog Engelsk
Tidsskrift Annals of Neurology
Udgivelsesdato nov 1983
Vol/bind 14
Tidsskriftsnummer 5
Sider 569-72
Antal sider 4
ISSN 0364-5134
DOI
Status Udgivet

Published in 1982

Originalsprog Engelsk
Tidsskrift Journal of Cerebral Blood Flow and Metabolism
Udgivelsesdato 1982
Vol/bind 2 Suppl 1
Sider S35-7
ISSN 0271-678X
Status Udgivet

Left-right cortical asymmetries of regional cerebral blood flow during listening to words

Nishizawa, Y., Olsen, T. S., Larsen, B. & Lassen, N. A. aug 1982 I : Journal of Neurophysiology. 48, 2, s. 458-66 9 s.

Publikation: Forskning - peer reviewTidsskriftartikel

1. Regional cerebral blood flow (rCBF) was measured during rest and during listening to simple words. The xenon-133 intracarotid technique was used and results were obtained from 254 regions of seven right hemispheres and seven left hemispheres. The measurements were performed just after carotid angiography, carried out to exclude space occupying lesions. In all subjects the angiogram was normal. All were right handed. 2. Mean hemispheric blood flow of both left and right hemispheres increased 10% from the resting measurement during the listening task. This increase was due in part to activation of the entire hemisphere. The focal rCBF increases were localized to the superior part of the temporal regions, the prefrontal regions, the frontal eye fields, and the orbitofrontal regions. Significant asymmetries were found in particular in the superior temporal region with the left side showing a more widespread and intense increase, averaging 29% as compared to 18% on the right side. This left-sided dominance during verbal stimulation should be compared to the right-sided dominance of rCBF during nonverbal sound discrimination reported by Roland et al. (25, 26), who used precisely the same technique as in the present study.
Originalsprog Engelsk
Tidsskrift Journal of Neurophysiology
Udgivelsesdato aug 1982
Vol/bind 48
Tidsskriftsnummer 2
Sider 458-66
Antal sider 9
ISSN 0022-3077
Status Udgivet

Published in 1981

Estrogens and portal hypertension in cirrhosis of the liver

Gluud, C., Henriksen, H. H. & Svenstrup, B. 1 jan. 1981 I : New England Journal of Medicine. 304, 1, s. 52

Publikation: Forskning - peer reviewTidsskriftartikel

Originalsprog Engelsk
Tidsskrift New England Journal of Medicine
Vol/bind 304
Tidsskriftsnummer 1
Sider (fra-til) 52
ISSN 0028-4793
DOI
Status Udgivet - 1 jan. 1981

Focal cerebral hyperemia in acute stroke. Incidence, pathophysiology and clinical significance

Olsen, T. S., Larsen, B., Skriver, E. B., Herning, M., Enevoldsen, E. & Lassen, N. A. 1981 I : Stroke. 12, 5, s. 598-607 10 s.

Publikation: Forskning - peer reviewTidsskriftartikel

In a consecutive study comprising 41 patients with completed stroke of less than 72 hours duration, cerebral angiography and measurements of the regional cerebral blood flow (rCBF) were performed within 24 hours after admission. The rCBF study was done using the 133-Xenon intracarotid injection method and a 254 multi-detector camera. CT scan was done 24 hours after the rCBF study. Focal cerebral hyperemia was found in 16 patients. The study revealed 3 different types of hyperemia: Border-zone hyperemia, surrounding ischemic areas, was seen in patients with occluded arteries on angiography, presumably resulting from accumulation of acid metabolites in the border-zone of acute infarcts. Postischemic hyperemia was seen in patients without occlusion, presumably due to recanalization of a prior occluded artery. Remote hyperemia was found distant from the infarcted area, presumably due to local tissue pressure on brain tissue. Cortical infarcts (10 patients) all had extensive hyperemic areas. Because the 254 detector camera has an excellent resolution in the cortical surface, our findings strongly suggest that all acute cerebral infarcts are, in fact, associated with hyperemic areas. The hyperemic areas are often extensive and vascular reactivity is commonly impaired. It is suggested that treatment aimed at reducing blood flow in hyperemic areas might improve prognosis.
Originalsprog Engelsk
Tidsskrift Stroke
Udgivelsesdato 1981
Vol/bind 12
Tidsskriftsnummer 5
Sider 598-607
Antal sider 10
ISSN 0039-2499
Status Udgivet

The possible role of hypertension on rCBF in acute stroke

Olsen, T. S., Larsen, B., Skriver, E. B., Herning, M., Enevoldsen, E. & Lassen, N. A. 1981 I : Journal of Cerebral Blood Flow and Metabolism. s. 508-9 2 s.

Publikation: Forskning - peer reviewTidsskriftartikel

Originalsprog Engelsk
Tidsskrift Journal of Cerebral Blood Flow and Metabolism
Sider (fra-til) 508-9
Antal sider 2
ISSN 0271-678X
Status Udgivet - 1981

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