Effect of pre- and postganglionic lesioning of the trigeminal nerve on cerebral blood flow and glucose metabolism following a subarachnoid haemorrhage in the squirrel monkey.

Simultaneous cerebral blood flow (CBF) and glucose metabolism (CMRglu) studies with a double isotope autoradiographic technique were applied to squirrel monkeys submitted to a unilateral pre- or postganglionic trigeminal lesion. The CBF values were not affected following a pre- or postganglionic lesion per se. In contrast, there was a global increase in the cerebral glucose uptake of about 50% as compared to controls following both kinds of lesions. Following a subarachnoid haemorrhage (SAH) 2-4 weeks after pre- or postganglionic trigeminal lesioning, there was a decrease in CBF similar to that seen in the control group. In the animals with a preganglionic lesion, the 50% increase in glucose uptake was not further augmented by a SAH and the increase in CMRglu was comparable to that found in control SAH animals. In the postganglionically lesioned monkeys, a SAH induced an additional increase in glucose uptake of about 50%. The findings suggest that the trigeminal system is involved in the regulation of cerebral metabolism via a brainstem centre.