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Biomedical subjects

J Risberg

Publications and source records attributed to J Risberg.

At least 91 records · Page 5Linked to original sources
PubMed1980

Regional cerebral blood flow in a case of amphetamine intoxication.

The regional cerebral blood flow (133Xe-inhalation method) was measured during acute amphetamine intoxication in a male 25 years old addict. During the study the patient displayed symptoms of paranoia and slight euphoria and tension. The flow level was found to be elevated by about 30% compared to a study in non-intoxicated state. The augmentation was most marked in the left hemisphere and in frontal regions (local increases up to 100%). The results confirm earlier findings in animal models and indicate the central role of frontal cortical structures in the production of psychotic symptoms.

Adult↗
PubMed1978

Effects of piracetam on regional cerebral blood flow and mental functions in patients with organic dementia.

The effects of piracetam (Nootropil, UCB6215) on mental functions and on regional cerebral blood flow (rCBF) were investigated in eight patients in the presenile age who displayed symptoms of moderate dementia. The double-blind crossover design included nine measurement occasions, each involving rCBF measurement by the 133-Xe inhalation method, ratings of symptoms of dementia, personality changes, and side effects, and a psychometric investigation. Three investigations were included in each of three treatment periods. The first investigation in a period was made without medication. Then either placebo or piracetam 4.8 g/day or 9.6 g/day was given during four weeks with measurements after 2 weekks and 4 weeks. There were intervals of 4 weeks without medication between the treatment periods. Piracetam had no significant effect on either mental functions or rCBF.

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↗
PubMed1978

Changes in regional cerebral blood flow following stereotactic psychosurgery.

Serial measurements of regional cerebral blood flow by the 133Xe inhalation method were performed in a pilot study in 6 patients undergoing stereotactic psychosurgical procedures (anterior capsulotomy, cingulotomy, frontobasal tractotomy). Average hemispheric flow did not change significantly from pre- to post-operative, but changes were seen in the patterns of regional flow distribution. The most striking finding was frontal flow reduction following capsulotomy. In view of the coupling of blood flow and function in the brain, the results indicate that this method offers a new way for exploring the effects of functional neurosurgery on brain activity.

Adult↗
PubMed1977

Regional cerebral blood flow in a case of bromide psychosis.

A case of bromide psychosis is described. A course of repeated measurements of the regional cerebral blood flow (rCBF) was followed, using the 133Xe inhalation method. At the first examination, when the serum bromide level was 45 mmol/1, the cerebral blood flow was reduced to about one-third of the normal. The regional flow pattern was also abnormal with low flows in frontal and parieto-occipital regions. Hemodialysis was performed with an overall improvement of the condition and a successive normalization of rCBF. The pronounced decrease of the cerebral blood flow, together with the positive effects of hemodialysis, seems to indicate that bromide psychosis is of a toxic origin and not an abstinence phenomenon.

Bromides↗
PubMed1977

Electroencephalographic changes in the dominant hemisphere during memorizing and reasoning.

The EEG was recorded with bipolar technique in ten normal subjects in the frontal, temporal and occipital regions of the dominant hemisphere in four situations: (1) during an auditory memory test, (2) during 'auditory rest' (listening to white noise), (3) during a visual reasoning test and (4) during 'visual rest' (watching a black dot on a white screen). Computer analysis of the EEG was made by (a) an on-line automatic EEG analyser yielding measures of mean power, mean frequency and frequency spread (complexity) and (b) an off-line period-amplitude (P-A) analysis, which gave per cent activity time and mean voltage in 21 frequency bands. As compared to auditory rest the auditory memory test gave an amplitude increase frontally in the alpha, theta, and delta bands. During the visual reasoning test there was in addition an amplitude increase in the alpha band in the temporal region. During the auditory test a tendency to a decrease of the alpha activity was seen in all three regions but this decrease occurred only occipitally during the visual test. The two types of mental activity thus induced two patterns of regional EEG changes. These showed principal similarities to regional cerebral blood flow patterns which have been recorded during visual and auditory tests of about the same types as those used in the present study.

Auditory Perception↗
PubMed1977

Cerebral dysfunction in alcoholism and presenile dementia. A comparison of two groups of patients with similar reduction of the cerebral blood flow.

Fifteen chronic alcoholics and 15 presenile patients were matched in pairs with regard to their mean hemisphere cerebral blood parameters-an index of brain metabolism. The distribution of the regional cerebral blood flow was similar in the two groups. The alcoholics performed significantly better in all psychometric tests than the presenile patients and more alcoholics than presenile patients were still employed and working. Nine presenile patients and one alcoholic showed symptoms indicating brain stem dysfunction. The measurements of the cerebral blood blow were made at rest while the psychometric testings and the evaluation of the social performance gave information about the brain at work. It is suggested that cerebral dysfunction in alcoholics to some extent can be partly overcome by brain activation procedures. In contrast, the defects of higher mental functions in presenile dementia cannot be compensated for.

Alcoholism↗
PubMed1975

Effects of promethazine on nocturnal sleep in normal man.

The effects of a phenothiazine, on sleep in ten healthy volunteers were investigated in two double blind polygraphic studies. The first part consisted of a single dose study with promethazine 50, 100, and 200 mg, using pentobarbital 100 mg as a reference substance. In the second part, four subjects spent 20 consecutive nights with nine drug nights (promethazine 100 mg), followed by a placebo withdrawal period of six nights, in the sleep laboratory. Promethazine showed a dose related REM-depressing effect with a greater decrease, the higher the dose. The placebo value was 20.7% REM of total sleep time and gave 16.3, 13.5 and 11.4 respectively, for promethazine 50, 100 and 200 mg. Pentobarbital gave 16.2% REM. There was also an increase of stage II and with the highest dose an increase of stage III + IV. An increase of REM-latency together with a decrease of REM-periods was also seen, and while pentobarbital gave a decrease in REM-density, promethazine did not cause any changes in the phasic REM-component. A REM-rebound was seen in the first night of withdrawal with an increase of per cent REM from 19.9%-25.1%. The mean for the whole withdrawal period was 23.1%. Promethazine in the highest dose, 200 mg, gave drowsiness and hangover effects in 14 nights out of 20. The REM-depressing effect of promethazine together with its relatively weak REM-rebound effect may explain its value in the treatment of withdrawal symptoms following abuse of alcohol and barbiturates.

Adult↗
PubMed1975

Effects of dixyrazine and methaqualone on the sleep pattern in normal man.

Whole night EEG and polygraphic recordings were made in ten young, healthy, male volunteers after dixyrazine (12.5 mg, 25 mg, 50 mg), methaqualone (250 mg) and Isonox (methaqualone 250 mg + etodroxizine 50 mg). A total of 156 recording nights (36 adaptation nights were not included in the analyses) were scored for different sleep stages according to accepted criteria. The smallest dose of dixyrazine (12.5 mg) had no significant effect upon sleep pattern: the larger doses (25 mg and 50 mg) caused significant decreases in REM-sleep during the first nights of administration. The decrease disappeared during the following two nights of treatment. No withdrawal effects were seen. Methaqualone also caused moderate depression of REM-sleep during the first night of treatment, and this effect, too, disappeared during prolonged administration. Isonox (methaqualone + etodroxizine) had a somewhat stronger surpressive effect upon REM-sleep than methaqualone alone.

Adult↗