A group of 15 persons with intractable central pains was selected for stereotaxic mesencephalic tractotomy; in 12, chronic depth electrodes were implanted in the mesencephalon and thalamus preceding therapy (Table 1). Of the 12 patients who were electrically stimulated, three had phantom arm pain and one a severe causalgic arm pain. Eight persons suffered from central pain or dysesthesia. The selection of this latter group of patients was based on Riddoch's definition of central pain as “spontaneous pain and painful over-reaction to objective stimulation resulting from lesions confined to the substance of the central nervous system, including dysesthesia of any kind.”10
|Case No.||Etiology||Site of Pathology||Type of Pain||Electrode Implants|
|1||Traumatic avulsion of arm||Brachial plexus||Phantom pain||4||Midbrain, medial and lateral Thalamus, sensory|
|2||Traumatic avulsion of brachial plexus||Plexus and spinal roots in cord||Phantom pain||2||Midbrain, lateral Thalamus|
|3||Traumatic avulsion of brachial plexus||Plexus||Phantom pain||2||Midbrain, lateral and ventral|
|4||Traumatic avulsion of plexus, incomplete||Brachial plexus||Causalgia||3||Thalamus, sensory Midbrain, medial and lateral|
|5||Trauma—Cerebral Stereotactic lesion, midbrain||Parietal lobe Dorsolat. tegmentum||Central pain face, arm, chest||4||Midbrain, medial and lateral thalamus, pulvinar, pretectal|
|6||Vascular thrombosis, post. inferior cerebellar artery||Medulla, lateral plate||Central pain face||3||Midbrain, medial and lateral Thalamus, sensory|
|7||Vascular thrombosis||Sensory thalamus Internal capsule||Central pain face, arm||3||Midbrain, medial, lateral and ventral Thalamus|
|8||Vascular thrombosis||Sensory thalamus Midbrain||Central pain face||2||Midbrain, medial and lateral|
|9||Cerebral hemorrhage Intracranial aneurysm||Thalamus Midbrain||Central pain face||3||Midbrain, medial and lateral Thalamus, sensory|
|10||Encephalomyelitis Thrombosis?||Thalamus||Central pain arm||1||Midbrain, lateral|
|11||Thrombosis? Multiple Sclerosis?||Thalamus||Central pain arm||4||Midbrain, lateral and medial Thalamus, sensory, pulvinar|
|12||Percutaneous chordotomy Arachnoiditis||Spinal cord, cervical and dorsal||Central pain arms, chest Phantom leg pain||3||Midbrain, medial Thalamus|
The cervical cord or the brachial plexus were the sites of pathologic involvement in the patients with phantom limb pain and the causalgia. In the eight patients with central dysesthesia, the pain was due to pathologic involvement at five sites in the central nervous system. These sites included the spinal cord, medulla, mesencephalon, thalamus, and the cerebral cortex (parietal lobe). There was additional clinical evidence for multiple sites of central nervous system involvement in two of these patients (Cases 5 and 12) with the central pain. Previous attempts had been made to relieve their pain by surgical interruption of the lateral spinothalamic tract in the spinal cord or the midbrain. Their original dysesthesia had then been replaced or intensified by a postoperative dysesthesia.
The etiological causes for the central pain were varied and included subarachnoid hemorrhage, cerebral thrombosis, encephalomyelitis, multiple sclerosis, spontaneous and surgical trauma. Severe trauma that had resulted in a traction injury to the arm, shoulder, and neck was the major cause of the pain in the patients with the phantom limb and the causalgia.
The pains centered in the phantom limb were always localized to the hand and fingers, while the pains associated with the central dysesthesia were more diffusely distributed and involved areas of the face, arm, chest, or abdomen.
ManningG. C.Jr. A new miniature multicontact electrode for subcortical recording and stimulating. Electroenceph. clin. Neurophysiol.196417:204–208.ManningJr. A new miniature multicontact electrode for subcortical recording and stimulating. Electroenceph. clin. Neurophysiol.17:204–208.
SpiegelE. A.WycisH. T. Stereoencephalotomy (thalamotomy and related procedures). Pt. I. Methods and stereotactic atlas of the human brain. New York:Grune and Stratton1952176 pp.SpiegelWycisStereoencephalotomy (thalamotomy and related procedures). Pt. I. Methods and stereotactic atlas of the human brain