The Anatomy and Physiology of the Mesencephalon and Thalamus from the Viewpoint of Surgical Control of Pain

Abstract

Our incomplete knowledge of the anatomical-physiological facts concerning pain undoubtedly provides a stumbling block for its neurosurgical control. So far we have not been able to elucidate whether this most complicated and complex sensation is performed primarily in the receptor elements, pain fibres of the periphery, spinal cord, brain stem, or in the thalamosubcortical and cortical structures. So far we have found out in blurred outline that the sensation of pain arises from irritation of certain nervous systems, whose involvement alters sometimes disadvantageously, sometimes however favourably, the experience of pain. These systems, getting more complicated on their way towards their subcortical and cortical termination, are interrupted at present for therapeutic reasons at different sites. The region of mesencephalon and thalamus offers many obstacles from this angle. Advances in the field of therapeutic interventions are for this reason very slow in this region, determined and guided by perfection in technique, as well as by continuing discoveries in the field of neurophysiology, histology and other disciplines.