Mild Propofol Sedation Reduces Frontal Lobe and Thalamic Cerebral Blood Flow: An Arterial Spin Labeling Study.

Mechanisms of anesthetic drug-induced sedation and unconsciousness are still incompletely understood. Functional neuroimaging modalities provide a window to study brain function changes during anesthesia allowing us to explore the sequence of neuro-physiological changes associated with anesthesia. Cerebral perfusion change under an assumption of intact neurovascular coupling is an indicator of change in large-scale neural activity.

Temporal dynamics of lactate concentration in the human brain during acute inspiratory hypoxia.

Purpose: To demonstrate the feasibility of measuring the temporal dynamics of cerebral lactate concentration and examine these dynamics in human subjects using magnetic resonance spectroscopy (MRS) during hypoxia.

Materials And Methods: A respiratory protocol consisting of 10-minute baseline normoxia, 20-minute inspiratory hypoxia, and ending with 10-minute normoxic recovery was used, throughout which lactate-edited MRS was performed. This was repeated four times in three subjects.