There has been some disagreement concerning the effect of pilocarpine on the sweat gland following degeneration of its postganglionic neuron. Brown and Adson1 gave pilocrapine to 4 subjects after lumbar and dorsal ganglionectomy, and visible sweating was induced in the areas which were usually dry. They stated:
This is evidence that degeneration of the sympathetic nerve-endings in the sweat glands had not occurred within the periods of the postoperative observations.
Lewis and Landis,2 on the contrary, stated:
It is quite clear that pilocarpine is capable of inducing sweating, and free sweating, in man after degeneration of the sympathetic nerves, and that it cannot be relied upon to mark the boundaries of sympathetic nerve lesions.
After cervicodorsal ganglionectomy List and Peet3 obtained pilocarpine sweating of the ipsilateral part of the face. They explained this by assuming that cholinergic fibers course through certain cranial nerves to innervate cutaneous vessels.
HYNDMAN OR, WOLKIN J. THE PILOCARPINE SWEATING TESTI. A VALID INDICATOR IN DIFFERENTIATION OF PREGANGLIONIC AND POSTGANGLIONIC SYMPATHECTOMY. Arch NeurPsych. 1941;45(6):992-1006. doi:10.1001/archneurpsyc.1941.02280180104008