Cerebral blood flow changes induced by electrical stimulation of the Gasserian ganglion after experimentally induced subarachnoid haemorrhage in pigs

Abstract

The effect of trigeminal electrical stimulation on cerebral blood flow has been studied in conditions of normal or reduced cerebral blood flow (CBF). Autologous blood was injected into the subarachnoid space of ten Pittmann-Moore pigs to induce subarachnoid haemorrhage (SAH) accompanied by cerebral blood flow (CBF) reduction. One week later, in six of ten animals, a considerable decrease of CBF was noted as evaluated by means of a recording-system monitoring over the right parieto-temporal calvarium the washout of 133Xenon injected into the internal carotid artery after the external carotid had been clamped. Continuous electrical stimulation of the Gasserian ganglion performed in the six animals with severely induced CBF reduction produced a remarkable cerebrovascular dilation and increase of CBF lasting over 3 h. Electrical stimulation of the Gasserian ganglion produced a similar pattern of vasodilation in six pigs in which no blood was injected and no reduction of CBF was evident. The mechanisms and the anatomical pathways which underlie these results are discussed.

Transcorneal stimulation of trigeminal nerve afferents to increase cerebral blood flow in rats with cerebral vasospasm: a noninvasive method to activate the trigeminovascular reflex

“…For example, Goadsby and associates 7,8 noted that stimulation of the trigeminal ganglion in the cat caused a reduction in both bulk carotid artery resistance and CVR by 39%. Salar, et al, 17 found that continuous stimulation of the ganglion maintained an increase in CBF of more than 100% in pigs; however, some other authors reported smaller increases in CBF, possibly due to partial and selective stimulation of the reflex arc and to differences in stimulation parameters. For instance, electrical stimulation of postganglionic fibers of the sphenopalatine ganglion induced a 32% increase in CBF in the ipsilateral parietal region in a rat study.…”

“…Continuous electrical stimulation of the gasserian ganglion in animals with reduced CBF produced a remarkable cerebrovascular dilation and flow increase that lasted more than 3 hours. In that study by Salar, et al, 17 however, the CBF measurements were obtained using the xenon inhalation technique and, thus, changes in CBF could not be continuously monitored as was done using the LD technique.…”

“…5,9,16,18,19 Currently, there is no effective treatment against posthemorrhagic cerebral vasospasm. Salar, et al,17 found that stimulation of the trigeminal nerve in pigs may dilate constricted cerebral arteries after experimental SAH, suggesting that activation of trigeminal afferents in patients with SAH may help improve the compromised CBF. Clearly, a noninvasive method is preferable for human applications.…”

“…11 Several authors have investigated the mechanism of trigeminal nerve-mediated vasodilation. 4,7,12,13,17,20 Cerebral blood vessels are innervated by sympathetic, parasympathetic, and trigeminal sensory nerve fibers, all of which play an important role in cerebrovascular regulation. 12 The ophthalmic division of the trigeminal nerve, which is the origin of the nasociliary nerve, is the primary sensory nerve to supply cerebral blood vessels.…”

Cerebral Vascular Control and Metabolism in Heat Stress

“…Indeed, the trigeminal ganglion is central to the cardiovascular adjustments associated with the mammalian diving reflex upon cold-water facial immersion (19), and releases known potent vasodilators, namely, substance P (309). In animals, trigeminal stimulation increases CBF (23,168,220,243,382). Similarly in humans, stimulation of the trigeminal ganglion by local injection of glycerol (451) or by thermocoagulation (450) yields marked increases in CBF.…”