Occult respiratory dysfunction in a craniovertebral anomaly.

Abstract

C RANIOVERTEBRAL ANOMALIES are developmental disorders that affect the skeleton and the enclosed neuraxis at the junction of the cranium and cervical spine. The two fundamental types of malformations result from faulty metameric segmentation or from dysraphic anomalies in the median sagittal plane. The associated clinical syndromes may he caused by any one of several factors, among which are bony deformities that produce compression or traction upon the neuraxis, intrinsic malformations of the nervous system, and disturbed circulation of cerebrospinal fluid. 2 The effect of these lesions on respiratory function has received scant attention in the literature. The hazards accompanying operative intervention were first appreciated by List 8 and were described secondarily by Mullan and Raimondi. 1~ The flexed position of the head, which is of utmost importance for proper surgical exposure, may stretch already compromised neural tissues and so produce changes in respiration which, if not corrected, may result in apnea and death. Pathological confirmation of respiratory peril was described by Bharucha and DastuP who, in 20 operations, reported four operative mortalities from ventilatory failure. Necropsy in two patients demonstrated areas of softening and hemorrhage in the cervicomedullary region. In a later communication, 4 a similar danger was associated with decompression of atlanto-axial dislocations.