Stereotactic cervical myelotomy.

The first spinal commissurotomy was performed by Armour and reported in 1927. The patient, suffering from tabetic gastric pain, died post-operatively. Putnam (1934) devised a similar procedure independently and advocated it for intractable pain in the arms and shoulders. The operation aimed at interrupting the decussating fibres passing to the spinothalamic tracts and, since the decussation was believed to take place over two to three segments for each dermatome, an attempt was made to split the commissure over several segments. Putnam's first patient was completely relieved of pain, and analgesia was produced from C5 to approximately T9 by splitting the commissure from C4 to T3, subsequently confirmed at necropsy. His second patient had only incomplete relief and a third patient died post-operatively. The method soon fell into disrepute because of cases of paralysis caused by injury to the anterior spinal artery. Leriche performed commissurotomy at lower levels in 1928 and reported it in 1936. It is now an established pain-relieving procedure, notably by French workers. Theoretically, cervical commissurotomy would be ideal for bilateral shoulder, arm, or upper chest pain which is uncommon. Unilateral arm or chest pain due to bronchial carcinoma, however, is relatively common and, although such pain can be relieved by high cervical cordotomy, pre-operative respiratory inadequacy may make the procedure hazardous due to injury to descending respiratory pathways (Belmusto, Brown, and Owens, 1963; Hitchcock and Leece, 1967). The advantages of a procedure which would not interfere with these pathways encouraged a reappraisal of the operation of cervical commissurotomy. The extensive laminectomy and myelotomy required, with the risk of injury to the anterior spinal artery, seemed to demand the use of a more precise method. Percutaneous stereotactic spinal tractotomy had been described, using a special stereotactic instrument (Hitchcock, 1969), and a similar technique has been used to interrupt the spinal commissure at the first cervical segment or cervico-medullary junction. MATERIAL AND METHOD