Neurolytic blocks: when, how, why.

Interventional techniques are divided into two categories: neuroablative and neuromodulatory procedures. Neuroablation is the physical interruption of pain pathways either surgically, chemically or thermally. Neuromodulation is the dynamic and functional inhibition of pain pathways either by administration of opioids and other drugs intraspinally or intraventricularly or by stimulation. Neuroablative techniques for cancer pain treatment have been used for more than a century. With the development of imaging facilities such as fluoroscopy, neuroablative techniques can be performed more precisely and efficiently.