Biomedical subjects

H End

Publications and source records attributed to H End.

2 recordsLinked to original sources

PubMed1998

[Sevoflurane and the nervous system].

During sevoflurane anaesthesia cerebral blood flow is preserved or slightly decreased. Cerebral oxygen consumption is reduced to 50% under 1 MAC sevoflurane. Autoregulation of cerebral blood flow and responsiveness of cerebral blood flow to changes in Pa CO2 are widely preserved. Sevoflurane produces a dose dependent increase in intracranial pressure and a decrease in cerebrovascular resistance that can not be observed under hypocapnic conditions. Central stimulus processing, the electroencephalogram and sensory evoked potentials are suppressed under sevoflurane in a dose dependent fashion. The electrophysiological data indicate that intraoperative awareness phenomena should be suppressed with sevoflurane 1.5-2.0 vol.%. Recovery of cognitive and psychomotor functions seems to be faster and more complete after sevoflurane than after isoflurane anaesthesia. In inducing seizure like EEG or muscle activity, sevoflurane seems to be comparable with isoflurane. There is no limitation of sevoflurane use in patients with concomitant psychiatric or neurological diseases, and sevoflurane may be valuable addition in neurosurgery or carotid surgery.

Anesthetics, Inhalation↗

PubMed1995

Individual differences in slow brain potentials in a guessing task.

18 healthy right-handed subjects had to predict one of two random non-equiprobable events by pressing one of two buttons with the right index finger. Each trial was preceded by a cue that increased the probability of the corresponding event in comparison to its overall probability. The Bereitschaftspotential (BP) before an action and the stimulus-preceding negativity (SPN) between the action and the event presentation were recorded. The subjects were subdivided into groups according to their tendency to follow the cue or to reject it. Cue rejection provided in the present situation a larger final gain than cue acceptance. Those subjects who used the former strategy were characterized by a local BP increase over the right parietal cortex, when a low-probable cue was presented. Their SPN amplitude was relatively small, but it increased substantially after a low-probable cue. Subjects who tended to follow the cue had a very large BP amplitude over the projection area and at vertex. Their SPN was overall large, regardless of condition. Peculiarities of the potentials recorded in these subjects are thought to relate to their desire to minimize errors.

Adolescent↗