The influence of bilateral electrical preganglionic sympathetic stimulation on intra- and extracranial blood flow

Sympathicotomy affects cutaneous blood flow, temperature, and sympathicus-mediated reflexes

OBJECTIVE

To study the sympathetically mediated effects of transthoracic endoscopic sympathicotomy (TES) in the treatment of severe primary palmar hyperhidrosis.

MATERIALS AND METHODS

The effects of TES, on sympathetic ganglia at the thoracic level of 2-3, finger blood flow, temperature, and on heat and cold provocation were investigated. Middle cerebral artery (MCA) blood flow velocities were studied by transcranial Doppler.

RESULTS

The finger blood flow increased by about 700% after TES and finger temperature by 7.0 +/- 0.5 degrees C. Several autonomic reflexes were dramatically affected. A finger pulp-shrinking test showed a major decrease after surgery. MCA mean blood flow velocities were not affected by TES.

CONCLUSIONS

Besides the high success rate of good clinical effect of TES on palmar hyperhidrosis, major effects on local blood flow and temperature are elicited by TES. Complex autonomic reflexes are also affected. The patient should be completely informed before surgery of the side effects elicited by TES.

Reactions of the middle meningeal artery of the cat to neural and humoral stimulation

The physiology and pharmacology of the middle meningeal artery was investigated in cats in order to determine whether this artery was subject to normal neural and humoral control mechanisms. Carotid and middle meningeal arterial blood flows and resistances were measured in 16 cats anaesthetized with chloralose. The cervical sympathetic nerves were stimulated electrically. Stimulation of the cervical sympathetic nerves pre-ganglionically reduced blood flow in the middle meningeal artery by producing vasoconstriction in its resistance bed. The vasoconstriction was mediated via catecholamine-containing nerves, as it was abolished by prior intravenous administration of bretylium. Intravenous injections of noradrenaline or adrenaline also produced vasoconstriction in the middle meningeal arterial bed. 5-Hydroxytryptamine (5HT), on the other hand, produced a dilatation in the middle meningeal artery. We conclude that neurally or humorally released catecholamines can provide a plausible mechanism for vasoconstriction in the middle meningeal artery. The dilator effect of 5HT contrasts with the constrictor effect of the 5HT1-like receptor agonist sumatriptan and suggests a complex 5HT receptor pharmacology for the artery.