Respiratory Function After Cervical cordotomy

¹ Assistant Professor of Medicine; Chief, Cardiopulmonary Laboratory, Albert Einstein College Hospital
² Resident, Neurological Surgery
³ Charles Frost Professor and Chairman, Department of Neurological Surgery, Albert Einstein College of Medicine

The effect of percutaneous cervical cordotomy on respiratory function was evaluated in 143 patients after unilateral cordotomy and in 37 patients after a bilateral procedure. Cervical cordotomy resulted in a reduction of FVC, MBC, minute ventilation and tidal volume, breathing both air and 5 percent CO₂, an increase in respiratory rate and a more irregular breathing pattern. These changes were greater following bilateral cordotomy than after a unilateral procedure, and were greater in patients who obtained a high level of analgesia. The impairment of motor function, indicated by the reduction of FVC and MBC, has been previously ascribed to section of efferent pathways to the phrenic nerve nuclei. The disturbance of respiratory control mechanisms indicated by hypoventilation, diminished CO₂ response and irregular breathing could not be explained by the reduction of motor function. On the other hand, the similarity of these changes to those seen with lesions of the lateral reticular formation, suggests that the disordered control mechanism following cordotomy is probably due to ablation of reticular formation tracts. Although it remains to be shown whether these are afferent or efferent pathways, the effect of cordotomy is consistent with deafferentation of the reticular formation.