There are three possible methods of anesthesia. One can anesthetize sensory nerve endings so that their stimulation gives rise to no afferent impulses. One can interrupt the transmission of afferent impulses by anesthetizing the nerve trunks which carry them. And finally one can stupefy the entire organism so that afferent impulses fail to register on arrival at the higher centers.
Anesthetization of the sensory endings has the advantage of safety, but for the patient it makes surgical procedure a harrowing experience, and the capacity of the tissues to heal is lowered by the necessary infiltration with fluid. The disadvantages of a general intoxication so profound that the higher centers are incapable of reacting to afferent impulses require no discussion.
Theoretically conduction anesthesia is much the best. There is no general intoxication, and no injury to the tissues involved in the operation. Spinal anesthesia is the ideal conduction method. In the
HARRISON PW. POSTANESTHETIC HEADACHE. Arch Surg. 1936;32(1):99-108. doi:10.1001/archsurg.1936.01180190102005