[Horners syndrome. A complication of the lateral recumbent position (author's transl)].

The appearance of a unilateral Horner's syndrome after an anesthetic in the lateral recumbent position is reported. It was caused by a damage to the sympathetic nerve at the level of Th 1 probably due to the extreme lateral flexion of the cervical vertebral spine. The importance of correct positioning of the head during anesthesia is stressed.