The role of the dorsal column pathway in visceral nociception.

Neurosurgeons have successfully used punctate midline myelotomy to relieve visceral cancer pain in human patients. Animal experiments demonstrate a visceral nociceptive pathway in the posterior column that is more effective than the spinothalamic tract in activating thalamic neurons, eliciting behavioral responses and triggering increases in regional cerebral blood flow. This visceral nociceptive pathway involves postsynaptic dorsal column neurons in the central, visceral processing region of the spinal cord. Axons from the sacral cord ascend near the midline and from the thoracic cord at the junction of the gracile and cuneate fasciculi.