Respiratory changes following percutaneous cervical (C2) cordotomy for intractable pain, were reported including a retrospective review of 13/200 patients with respiratory complications; and a prospective study of pulmonary function in 41 patients. Three of 13 patients had sleep-induced apnea following bilateral cordotomy and required artificial ventilation for 1-3 months. Following unilateral cordotomy, mean FVC [forced vital capacity], MEFR [maximal expiratory flow rate] and PaO2 [arterial O2 pressure] in all 41 patients were not lowered. Seven of 41 patients developed dyspnea post-cordotomy; 2 needed temporary artificial ventilation; but 6/7 had greatly reduced pulmonary function pre-cordotomy. Two developed phrenic palsy without dyspnea. Following cordotomy on the 2nd side (17 patients) there was a significant reduction in MEFR, FVC and PaO2 values, greater in the 7/17 who became dyspneic. Three developed phrenic palsy with dyspnea.