Ik raad iedereen aan de onderstaande wetenschappelijke studie van Pim van Lommel zorgvuldig te lezen:
Over activiteit in de brein staat er het volgende:
NEUROPHYSIOLOGY DURING CARDIAC ARREST
Through many studies in both human and animal models, cerebral function has
been shown to be severely compromised during cardiac arrest, with sudden loss
of consciousness and of all body reflexes, but also with the abolition of brain-stem
activity with the loss of the gag reflex and of the corneal reflex, and fixed and dilated
pupils are clinical findings in those patients (Parnia and Fenwick, 2002). And also
the function of the respiratory center, located close to the brainstem, fails, resulting
in apnoea. Complete cessation of cerebral circulation is found in induced cardiac
arrest due to ventricular fibrillation (VF) during threshold testing at implantation
of internal defibrillators. This complete cerebral ischemic model can be used to
study the result of anoxia of the brain. The middle cerebral artery blood flow, Vmca,
which is a reliable trend monitor of the cerebral blood flow, decreases to 0 cm/sec
immediately after the induction of VF (Gopalan et al., 1999).
Electrical activity in
both cerebral cortex and the deeper structures of the brain has been shown to be
absent after a very short period of time. Monitoring of the electrical activity of the
cortex (EEG) has shown that the first ischemic changes in the EEG are detected an
average of 6.5 seconds from the onset of circulatory arrest, and with prolongation
of the cerebral ischemia always progression to isoelectricity occurs within 10 to
20 (mean 15) seconds (De Vries et al., 1998; Clute and Levy, 1990; Losasso
et al., 1992; Parnia and Fenwick, 2002). After defibrillation the Vmca, measured by
transcranial Doppler technique, returns rapidly within 1β5 seconds after a cardiac
arrest of short duration (Gopalan et al., 1999). However, in the case of a prolonged
cardiac arrest of more than 37 seconds, normal EEG activity may not return for
many minutes to hours after cardiac function has been restored, depending on the
duration of the cardiac arrest, despite maintenance of adequate blood pressure in
the recovery phase (Smith et al., 1990). Additionally, EEG recovery sometimes
underestimates the metabolic recovery of the brain, and cerebral oxygen uptake
may be depressed for a considerable time after restoration of circulation (De Vries
et al., 1998).
Bron en wetenschappelijke referenties:
http://www.pimvanlommel.nl/files/public ... 0Brain.pdf" onclick="window.open(this.href);return false;