A NEW METHOD OF IN-VIVO MICRODIALYSIS OF THE HUMAN BRAIN

In-vivo microdialysis has been used extensively to study the neurochem ical mechanisms of ischemia, epilepsy and hypoglycemia. It is also bei ng increasingly used to document the response of neurons to various me dications. Most of the work to date has been done in small animals. In the last 2 years, the technique has been adapted for use in patients with subarachnoid hemorrhage, head trauma, Parkinson's disease, brain tumors and epilepsy. Two of the major limiting factors are the invasiv eness of the technique and the resultant potential for CNS infection. We describe a simple, safe and reliable method to measure neurochemica l changes in the human brain with in-vivo microdialysis. We were able to easily monitor for 4-6 h daily for up to 4 days in awake or comatos e patients with subarachnoid hemorrhage or head trauma. Cerebral conce ntrations of glutamate, GABA, other amino acids and catecholamines wer e measured. This technique thus has a potential for on-line measuremen ts of neurotoxins in patients with unstable neurological conditions.