A patient with migraine who had a permanent visual field defect was studied by angiography and CT scan. He also had a tomographic study of cerebral blood flow (CBF) and oxygen extraction fraction (EO2) using the non-invasive continuous oxygen-15 (15O) inhalation technique. Angiography was normal. CT scan revealed an area of decreased density with contrast enhancement suggestive of a recent infarct in the left occipital lobe. The 15O inhalation technique showed a decrease in CBF and EO2, typical of recent infarcts, in the corresponding area, an increase in CBF with normal EO2 in the left temporal lobe, and a decrease in CBF with increased EO2 in the right occipital cortex. These findings illustrate the unusual nature and extent of the ischemic process underlying migrainous cerebral infarction.

Cerebral Angiography↗

PubMedDate not supplied

Reversal of focal "misery-perfusion syndrome" by extra-intracranial arterial bypass in hemodynamic cerebral ischemia. A case study with 15O positron emission tomography.

Tomographic images of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) using the 15O continuous inhalation technique, and positron emission tomography, were obtained from a patient with cerebral ischemia distal to an occluded left internal carotid artery. There was a focal mismatch between CBF and oxygen metabolism in the brain supplied by the middle cerebral artery where CBF was decreased and OEF increased ("misery-perfusion syndrome" as opposed to "luxury-perfusion syndrome"). These abnormalities were most marked in the parieto-occipital watershed area. After left superficial temporal to middle cerebral artery anastomosis, the clinical attacks ceased and a repeat study did not demonstrate the previous CBF and OEF abnormalities. This suggests that this pattern of abnormalities indicates potential viable tissue. The concept of "misery-perfusion" may be of some importance in the pathophysiological mechanisms of hemodynamic cerebral ischemia and serve as a rational basis for revascularization procedures.

Aged↗

PubMedDate not supplied

Regional cerebral blood flow and oxygen consumption in human aging.

The oxygen-15 continuous inhalation technique and PET were used to study the age-related changes in regional CBF and CMRO2. Twenty-seven patients, aged 19 to 76 years, free of any history of cerebral disease and vascular risk factors were examined in "resting state." CBF, CMRO2 and oxygen extraction fraction (OEF) values were calculated in seven different brain structures as well as in mean gray matter. Left-right ratios were also computed for all symmetrical structures analyzed. Mean gray CBF, but not mean gray CMRO2, decreased linearly with age (p less than 0.02). However, when younger subjects (less than or equal to 50 yrs) were compared to older subjects (greater than 50 yrs), an age-related matched decrease in CBF and CMRO2 was observed in mean gray matter (18% and 17%, p less than 0.05) and in all gray matter regions analyzed, particularly in frontal, temporo-sylvian and parieto-occipital cortex. White matter CBF and CMRO2 remained remarkably stable with advancing age. Although the possibility of methodological artifacts was considered, we favor progressive loss of cortical neurones and/or diminished activity of those remaining to explain our findings. In addition, age-related changes in cognitive activities might also be involved.

Adult↗

PubMedDate not supplied

[Estimates of trace elements requirements of children receiving total parenteral nutrition].

Ten children on total parenteral nutrition were studied. Plasma copper, zinc, manganese and selenium levels were determined by neutron activation and gamma spectrometry, every 10 days. With a copper intake of 20 microgram/kg/24 h, the average level 120 microgram% (94-144) was normal (N: 118 microgram +/- 11%). With a manganese intake of 40 microgram/kg/24 h, the level increased to 2.6 microgram% (1.3-4.5) (N: 1.1 microgram +/- 0.2%). With a zinc intake of 30 microgram/kg/24 h, the level decreased to 45.9 microgram % (20-63) (N: 83 microgram +/- 28%); with an intake of 50 microgram/kg/24 h the level remained under normal. With a selenium intake of 1 microgram/kg/24 h, the level decreased to 10.6 ng/ml (3.6-21.6) (N: 38.2 ng/ml +/- 11.9), but was normalized with an intake of 3 microgram/kg/24 h. From these results, with all reserves that estimation implies, the authors suggest that the disorders due to deficit or excess of trace elements could be avoided by daily intakes per kg of body weight: copper 20 microgram, zinc 100 microgram, manganese 10 microgram and selenium 3 microgram, with supplementation of iron, iodine and fluoride.

Child↗

PubMedDate not supplied

[Quantitative study of iodine metabolism in a case of hypothyroidism with goiter due to a defect of iodotyrosine deshalogenase].

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Autoradiography↗

PubMedDate not supplied

Comparison study of CT and positron emission tomographic data in recent cerebral infarction.

To better understand the pathophysiologic correlates of the computed tomographic (CT) scan changes seen in recent cerebral infarction, 17 patients (20 studies) underwent both x-ray transmission and positron emission CT investigations within 18 days after clinical onset of complicated ischemic stroke in the internal carotid artery territory. The density changes before and after contrast study measured within the CT lesion were correlated to the local cerebral blood flow (CBF), oxygen utilization (CMRO2), and oxygen extraction fraction (OEF) measured with the oxygen-15 steady-state positron technique. Statistically significant linear correlations were found between hypodensity and CBF, hypodensity and CMRO2, and contrast enhancement and CBF, such that the more CBF and CMRO2 were depressed, the more marked was the hypodensity; and the more CBF was elevated, the more marked was the contrast enhancement. Although marked contrast enhancement was associated with decreased OEF (luxury perfusion), it was only rarely associated with increased CBF. Various hypotheses are discussed to explain these findings.

Brain↗

PubMedDate not supplied

Cyclotrons for medical use: characteristics and installation aspects.

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Particle Accelerators↗