Neurological concepts of pain management in head and neck cancer.

The physiological basis, historical evolution, and our own practice of stereotactic surgery for the relief of cancer pain are briefly described. Thirty-nine procedures have been performed on 33 patients, 27 for pain due to cancer. Lesions have been made both in the specific neospinothalamic pathway of midbrain and thalamus and in the non-specific reticulothalamic system with an overall five per cent mortality and five per cent morbidity. Initial pain relief was achieved in 90 per cent of patients with relief till death in 74 per cent. Lesions were more successful in releiving pain when the specific pain system was involved but only if the analgesia produced by the lesion "covered" the patient's pain. On the other hand, dysesthesia occurred only with lesions of the specific system, especially if they involved the thalamus.