Bi-frontal Stereotactic Tractotomy: An Atraumatic Operation of Value in the Treatment of Intractable Psychoneurosis

Abstract

Stereotactic surgery has provided a means of producing accurate lesions at selected points in the nervous system where concentrations of nerve cells or fibre pathways possessing specific functions permit some small area of anatomical destruction to produce widespread physiological effects. The value of this method in relation to motor and sensory activity is illustrated by the results of thalamotomy in the treatment of Parkinsonian tremor and by stereotactic division of the spinothalamic tract in the cervical cord for the relief of incurable pain. The accuracy of approach and minimal disturbance of tissue ensures that the beneficial effects of these operations are produced in isolation without associated disfunction in the nervous system. That a similar principle can be applied in relation to the control of emotion has been shown in cases of intractable psychoneurosis treated by the operation of bifrontal stereotactic tractotomy in the substantia innominata (Knight, 1964). Owing to the influence of emotion in psychoneurotic states it is possible to influence many syndromes satisfactorily by operation at a site where connections of the limbic system concerned with instinctive and emotional activity rather than cognitive processes converge to a point beneath the head of the caudate nucleus, thereby producing a reduction in the intensity of emotional reaction without undesirable personality change or post-operative epilepsy. It is felt that it would be useful to summarize the anatomical features in order that the differences between this operation and the old leucotomy procedure can be generally appreciated. It is particularly among cases of chronic and recurrent depression that this form of surgery can be most usefully employed.