The first in vivo experience of the effects of the continuous intrathecal infusion of clonidine on the locus coeruleus in the regulation of cerebral blood flow: a TCD study.
This was a study of the action of continuous intrathecal clonidine infusion on the locus coeruleus in the regulation of cerebral blood flow (CBF) by means of a test of the activation of the locus coeruleus (cold pressure test, CPT).


METHODS
The effects on CBF of intrathecal clonidine used for analgesic purposes in a patient with a chronic painful benign syndrome were studied by means of transcranial Doppler sonography (TCD) before and after administering the CPT.


RESULTS
TCD with the infusion device activated revealed an increase in CBF velocities compared with those recorded when the device was inactivated. During CPT with the infusion device inactivated, TCD showed a decrease in CBF velocity: this decrease was less when the device was activated.


CONCLUSIONS
Our results suggest that the intracerebral vascular responses induced by CPT and intrathecal clonidine infusion may be related to a sympathetic regulating mechanism of cerebral vascularization, possibly mediated by locus coeruleus.
Bramanti
P
P
Centro per lo Studio ed il Trattamento dei Neurolesi Lungodegenti, Cattedra di Neurofisiopatologia, Università di Messina, Italy.
Mariani
C A
CA
D'Aleo
G
G
Malara
A
A
D000328:Adult; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D003000:Clonidine / Q000494:pharmacology*; D006801:Humans; D007278:Injections, Spinal; D008125:Locus Coeruleus / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial
D003000:Clonidine