Biomedical subjects

H Skeidsvoll

Publications and source records attributed to H Skeidsvoll.

6 recordsLinked to original sources

PubMed1991

Electroencephalography, evoked potentials and MRI brain scans in saturation divers. An epidemiological study.

One hundred and fifty-six air and saturation divers, mean age 33.6 (range 21-49) years, were examined. The control group consisted of 100 offshore workers and policemen with the health requirements to have a diving certificate, mean age 34.0 (range 22-48) years. The examination protocol included electroencephalography (EEG), visual evoked potentials (VEPs), brain-stem auditory evoked potentials (BAEPs) and magnetic resonance imaging (MRI) of the brain and brain-stem. Abnormal EEGs, with focal slow waves mostly in the temporal regions and sharp potentials, were found in 18% of the divers and in 5% of the controls (P = 0.003). Abnormal EEGs correlated significantly with the exposure to saturation diving (P = 0.0006) and the prevalence of decompression sickness (P = 0.0102). Alcohol consumption was negatively correlated with abnormal EEGs (P = 0.0006). Mean I-III BAEP latency was increased (P = 0.047) in the diver group. P100 VEP latency decreased with age (21-49 years). High signal intensity changes obtained by MRI were found in 33% of the divers and in 43% of the controls (P = 0.14). It is concluded that the nervous system of saturation divers is influenced by their occupation and that EEG is a useful method in the health examination of divers.

Adult↗

PubMed1991

Neurological long term consequences of deep diving.

Forty commercial saturation divers, mean age 34.9 (range 24-49) years, were examined one to seven years after their last deep dive (190-500 metres of seawater). Four had by then lost their divers' licence because of neurological problems. Twenty seven (68%) had been selected by neurological examination and electroencephalography before the deep dives. The control group consisted of 100 men, mean age 34.0 (range 22-48) years. The divers reported significantly more symptoms from the nervous system. Concentration difficulties and paraesthesia in feet and hands were common. They had more abnormal neurological findings by neurological examination compatible with dysfunction in the lumbar spinal cord or roots. They also had a larger proportion of abnormal electroencephalograms than the controls. The neurological symptoms and findings were highly significantly correlated with exposure to deep diving (depth included), but even more significantly correlated to air and saturation diving and prevalence of decompression sickness. Visual evoked potentials, brainstem auditory evoked potentials, and magnetic resonance imaging of the brain did not show more abnormal findings in the divers. Four (10%) divers had had episodes of cerebral dysfunction during or after the dives; two had had seizures, one had had transitory cerebral ischaemia and one had had transitory global amnesia. It is concluded that deep diving may have a long term effect on the nervous system of the divers.

Adult↗

PubMed1991

Volumes of chronic traumatic frontal brain lesions measured by MR imaging and CBF tomography.

The volumes (ml) of chronic traumatic frontal brain lesions were compared measured "morphologically" with MR imaging (T1 and T2 weighted images) and "functionally" with a tomographic rCBF technique (SPECT with 133Xe i.v.). The T1 volumes varied between 11 and 220 ml. The correlation between T1 and T2 volumes was 0.95, the T2 volumes being 33% larger than T1 volumes (p less than 0.001). The functional SPECT volumes were considerably larger (range 16-324 ml) than the MR volumes. The mean volume difference was 81% between T1 and SPECT images (p less than 0.001), and 35% between T2 and SPECT images (p less than 0.001). Correlations between the MR and SPECT volumes were also higher for T2 than T1 volumes. The volume difference is most likely explained by a functional decrease in regions around the lesion in which no morphologic change visible on MR images had taken place. MR and SPECT volume measurements were positively related to persistent lack of energy and personality changes, but only moderately related to duration of impaired consciousness and neuropsychologic outcome.

Adult↗

PubMed1989

Delayed decrease in hemispheric cerebral blood flow during Wada test demonstrated by 99mTc-HMPAO single photon emission computer tomography.

We describe how brain regions with a flow (and metabolism) decrease can be visualized after an injection of short-acting barbiturate in one of the internal carotid arteries during a Wada test. An intravenous administration of 99mTc-HMPAO (Ceretec) was used to mark the relative flow distribution. The 99mTc-HMPAO distribution in the brain was recorded three-dimensionally about 1 h later, by means of a single photon emission computer tomograph. We show that the timing of the intravenous 99mTc-HMPAO administration during the Wada test is important for the visualization of the low-flow regions. The administration of the tracer substance should be delayed at least 30 s after the first signs of the barbiturate effect. The rCBF decrease in the barbiturate-injected cerebral hemisphere was associated with a simultaneous decrease in the contralateral, pharmacologically not directly affected, cerebellar hemisphere (crossed cerebellar diaschisis).

Adult↗

PubMed1989

The effects of nitrazepam and flunitrazepam on oxygen desaturation during sleep in patients with stable hypoxemic nonhypercapnic COPD.

Serious respiratory depression has been described in COPD patients receiving hypnotics during acute exacerbations. There are few studies quantifying the effects of hypnotics on oxygenation during sleep in patients with stable hypoxemic COPD. In this study, the effects of single therapeutic doses of nitrazepam and flunitrazepam on SaO2, apneas during sleep and other sleep variables were measured in 14 COPD patients. All patients used theophylline. Sleep-induced decrease in mean SaO2 was 1.3 percent after placebo, 1.4 percent after nitrazepam and 1.9 percent after flunitrazepam (no significant differences). Sleep apneas were not more common or longer after nitrazepam or flunitrazepam, but sleep quality seemed to improve. It is concluded that oxygenation during sleep in these nonobese patients with stable hypoxemic nonhypercapnic COPD, all on maintenance theophylline therapy, was affected very little by single therapeutic doses of nitrazepam or flunitrazepam.

Aged↗

PubMedDate not supplied

Cerebral hemodynamic changes and electroencephalography during carotid endarterectomy.

Some patients undergoing endarterectomy for occlusive carotid artery disease run a risk of brain ischemia during cross-clamping of the artery. The present study of 15 patients was undertaken to evaluate changes in cerebral blood flow (CBF), as measured with an intravenous (IV) tracer (133Xenon) technique, and to relate CBF changes to changes in the electroencephalogram (EEG). CBF was measured before and after induction of anesthesia, during cross-clamping of the carotid artery, after release of the clamps, and at 24 hours after the operation. All the patients were anesthetized with methohexitone, fentanyl, and nitrous oxide and oxygen. EEG was continuously recorded during the operation. Carotid artery shunts were not used. In 8 patients, cross-clamping of the carotid artery did not influence the EEG. In this group of patients, induction of anesthesia caused a 38% decrease in CBF, which presumably reflects the normal reaction to the anesthetic agent given. There were no further changes in CBF during cross-clamping. In 7 patients, the EEG showed signs of deterioration during the intraoperative vascular occlusion. In these patients, anesthesia did not cause any CBF change, whereas cross-clamping the artery induced a 33% decrease in CBF. In individual patients, the severity of EEG changes correlated with the decrease in CBF. The absence of a change in CBF by anesthesia and a decrease due to cross-clamping of the carotid artery may be explained by the presence of a more advanced cerebrovascular disease and an insufficiency to maintain CBF during cross-clamping.(ABSTRACT TRUNCATED AT 250 WORDS)

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