Central Pain

Central pain syndromes are notoriously one of the most difficult pain syndromes to treat. Central pain can arise form a lesion anywhere within the central nervous system, but usually the lesion involves the spinothalamic tract. Thus, both spinal cord injuries, such as from trauma, or brain lesions, such as from a stroke, can result in pain. The incidence is variable, and has been reported to be anywhere from 7.5% to 40% in spinal cord injuries. For strokes, the incidence is much lower, on the order of 1 in 1500 cases. Two types of pain exist with central pain: spontaneous pain and hypersethesia. Hyperesthesia can be intense discomfort produced by a mild or moderately painful stimuli, or an unpleasant sensation produced by a normally nonoxious stimuli.

Medical treatment of central pain includes barbiturates, dilantin, carbamazepine, and clonazepam. Narcotics are historically ineffective in treating pain, but results may be obtained if high dose therapy is initiated. Central administration of opiates has been used, as well as other intraspinal agents, such as clonidine, neostigmine, and local anesthetics. Spinal cord stimulation can be attempted for well-localized pain, but the success rates have been much lower than for other conditions.

Neurosurgical interventions for central pain, such as cordotomy, rhizotomy, and dorsal root entry zone lesioning, or DREZ, have achieved good results when studied short term, but unfortunately, the long term results are poor.