Experimental deafferentation syndromes.

Animal models of dysesthesias have been established, and reveal the following major points. Dysesthesias of peripheral nerve or dorsal root origin have a central neural cause. Chronic dysesthesias of spinal origin have a cause which resides in the brain. The origins of these effects are lesions in the spinothalamic system. The causes of these effects are abnormal functionings among opiate, catecholamine, and purine pathways. Denervation supersensitivity is suggested.