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Biomedical subjects

D H Ingvar

Publications and source records attributed to D H Ingvar.

At least 55 records · Page 3Linked to original sources
PubMed1981

Measurements of regional cerebral blood flow and metabolism in psychopathological states.

In different psychopathological states like focal epilepsy, organic dementia, and chronic schizophrenia, rCBF studies have previously demonstrated specific changes of the normal cerebral perfusion landscape. It has been assumed that these abnormalities - the hyperemia in epileptic foci, the regional reduction pattern in dementia as well as the abnormal flow distribution in chronic schizophrenia - represent metabolic alterations. Recent studies with positron emission tomography give solid support to this hypothesis. The glucose uptake in epileptic foci is increased and the uptake in the frontal cortex is reduced in chronic schizophrenia. The metabolic studies show that regional cerebral activity in various psychopathological states is now accessible to a detailed study.

Cerebrovascular Circulation↗
PubMed1980

Normal sleep pattern analyzed statistically and studied by color "dormograms".

Polygraphic sleep recordings were made from 46 healthy adult volunteers during 159 nights and evaluated visually. Sleep stages for each 30 sec epoch were entered into a computer data base from which plots of individual nights, as well as color "dormograms" and/or statistical parameters for a set of nights, could be produced. The total mean dormogram in which all the nights were synchronized at sleep onset revealed a dominant sleep pattern, which was found to be very stable even for subgroups. Synchronizing at the beginning of the second REM period allowed the pattern for the last half of the nights to appear more clearly. A large number of different sleep parameters were calculated for each night and statistically analyzed. On the basis of these results a normal "mean" sleep pattern could be reconstructed and related to other studies of normal sleep patterns.

Adult↗
PubMed1979

EEG and cognitive impairment in presenile dementia.

EEG and psychometric findings were studied in a group of 57 patients consisting of 19 cases of Alzheimer's disease, 7 cases of Pick's disease, 24 cases of cerebrovascular dementia (CVD) and a group of 7 cases with dementia of various other etiology. The diagnoses have so far been confirmed by autopsy in 23 out of 57 cases. EEG was evaluated by means of visual inspection. Psychometric studies enabled a classification into 5 psychometric defect groups according to the degree of dementia. An overall good correlation was found between the degree of dementia and EEG abnormality. A significant correlation between the test socre and the EEG was found only for the vocabulary test and paired associates test. However, on the reaction time test, color word test, and Koh's block design test, large patient groups were untestable, and a highly significant correlation was found between non-testability and severely abnormal EEG. The Alzheimer and the CVD groups differed distinctly, most of the Alzheimer cases showing a severe or moderate degree of EEG abnormality and dementia, whereas in the CVD cases, the dementia was less pronounced and the EEG often normal or only slightly abnormal. Four out of seven cases of Pick's disease had a normal EEG, which distinguished them from the Alzheimer cases which had a comparable psychometric defect.

Adult↗
PubMed1979

"Hyperfrontal" distribution of the cerebral grey matter flow in resting wakefulness; on the functional anatomy of the conscious state.

Regional cerebral blood flow was measured with the intra-arterial 133 Xenon clearance technique using a multidetector device in 11 patients undergoing carotid angiography (with normal findings). During the flow studies the patients were awake and strict resting conditions were observed. The patients did not move or speak, and sensory stimulation were kept at a minimum. It was confirmed that the distribution of the grey matter blood flow showed a hyperfrontal pattern, the flow in frontal regions being significantly (20-40%) higher than in postcentral, occipital and temporal regions. There were no technical factors or morphological features of the telencephalon which could explain this difference. It was also shown that the distribution of the white matter flow and the relative weight of the grey matter corresponded in general to hemisphere morphology. Since in normal nervous tissue the blood flow is regulated by the neuronal activity, the following interpretation is given of the main finding. The hyperfrontal flow distribution of the grey matter (cortical) flow during resting wakefulness shows that there is a high activity in frontal "efferent" (motor-behavior) regions. At the same time there is a low activity in post-central and temporal "afferent" (sensory-gnostic) cortical areas. The high frontal activity suggests that in the resting conscious state--unaccompanied by movements, speech or behavioral reactions--the brain is active with an anticipatiory "simulation of behavior". The low postcentral flow, on the other hand, may possibly be related to a global inhibition of the sensory input. Several clinical as well as general biologic arguments are forwarded to support this interpretation. It is further pointed out that the hyperfrontal distribution of the resting activity in the cerebral cortex correlates to the resting EEG, in which lower frequencies (the alpha rhythm) predominate in postcentral and temporal regions where there is a low flow/activity, and high frequencies in frontal areas where the blood flow is high. This is in agreement with the finding that the blood flow and metabolism of the brain correlate to the EEG frequency content.

Aged↗
PubMed1978

Neurocirculatory analysis of potential EIAB patients.

Twelve patients with gross vascular occlusions and with infarcts demonstrated in CT were examined with regard to their hemodynamic situation. Angiography and rCBF with intra-arterial and inhalation techniques were performed. Response to increased arterial hypertension and to CO2 inhalation was tested. It is concluded that one technique alone does not provide enough information for the selection of patients suitable for EIAB operation.

Brain Ischemia↗
PubMed1977

Evaulation of the effect of fosazepam (a new benzodiazepine), nitrazepam and placebo on sleep patterns in normal subjects.

The nocturnal sleep of eight healthy young volunteers was studied after placebo, Fosazepam 100 mg and Nitrazepam 10 mg. Overall results were very similar after the two drugs. During drug periods there was less of sleep Stages I, III + IV and REM, compensated by an increase in Stage II. The decrease in SWS (III + IV) persisted during the withdrawal periods. There was also an increase in Stage I during Fosazepam withdrawal, whereas the percentage of other sleep stages returned to normal. Sleep quality was reported to be slightly better and morning drowsiness, as well as hangover effects, were said to be less pronounced after Fosazepam than after Nitrazepam.

Adult↗
PubMed1977

Distribution of cerebral blood flow in the dominant hemisphere during motor ideation and motor performance.

Distribution of activity in the dominant (left) hemisphere was studied with a multidetector instrument during diagnostic measurements of regional cerebral blood flow in 6 patients, 4 of them neurologically normal. Computercalculated charts, in color, of the flow/activity distribution--"cerebral ideograms"-- were obtained in three situations: at rest, during motor ideation (attempts to conceive of rhythmic clenching movements of the right hand), and during actual movements of the right hand. Motor ideation changed the normal "hyperfrontal" resting flow distribution, and an increase of the hemisphere mean flow was recorded. The increase was especially marked in frontal and temporal structures. This pattern differed from the one during actual hand movements, when a rolandic flow increase was seen. The result suggests that centers for motor ideation have a different cerebral location than those which control the actual hand movement.

Adult↗