The whole problem of peripheral pain reception and central pain perception and representation remains one of the fundamental fields of investigation in neurophysiology and clinical neurology. Certain aspects of the problem are of considerable interest to the neurosurgeon. For many patients suffering from persistent intractable pain of organic origin, interruption of the central pain pathways offers a palliative measure. Because dorsal root section severs all afferent paths to the spinal cord, the most successful central interruption is obtained by cutting the lateral spinothalamic tract somewhere along its course. Its relatively superficial position renders it accessible to anterolateral chordotomy, to an incision dorsolateral to the inferior olivary nucleus or to an incision at the lateral sulcus of the mesencephalon. The literature concerning this neurosurgical field has been extensively reviewed,1 and only pertinent references will be included here.
These neurosurgical procedures depend partly for their success on an accurate anatomic knowledge