High incidence of cardiopulmonary complications associated with implantation of adrenal medullary tissue into the caudate nucleus in patients with advanced neurologic disease. OBJECTIVE: The purpose of our study was to examine the cardiopulmonary complications of a group of patients who had undergone implantation of adrenal medullary tissue into the caudate nucleus for treatment of neurologic disease. DESIGN: Prospective study with partially matched historical controls. SETTING: Tertiary care community medical center. PATIENTS AND METHODS: Seven patients with advanced Parkinson's disease and three patients with progressive supranuclear palsy underwent implantation of adrenal medullary tissue into the caudate nucleus. These patients were compared with respect to their cardiopulmonary complications with a control group who had undergone craniotomy and then compared with a control group who had undergone only abdominal surgery. RESULTS: In the study group, six patients developed major postoperative complications including development of large pleural effusions, lobar atelectasis, pneumonia, upper airway obstruction, and cardiac arrest. Three patients had minor complications including development of small pleural effusions, subsegmental atelectasis, purulent bronchitis, mild congestive heart failure, and atrial flutter/fibrillation. One patient had an unremarkable postoperative course. The first control group, whose only surgery was a craniotomy, had only one major complication. The second control group, the abdominal surgery control group, had one major and five minor complications. CONCLUSION: The particular neurologic disease, its severity, and the type of surgery performed appear to be causative factors in the high incidence of complications in the study group. 