Vocal fold paralysis following spinal anesthesia

Transient upper cranial neuropathy is a well-described complication of spinal anesthesia. Lower cranial neuropathies, in particular vagal neuropathies, have not been described. We present 4 cases of vocal fold paralysis (VFP) in 3 patients following spinal anesthesia and discuss a proposed mechanism.

Three women presented with dysphonia following spinal anesthesia and were found to have unilateral VFP. Patient 1 presented with dysphonia immediately after knee surgery. Patient 2 developed right VFP 1 week after vaginal delivery with spinal epidural anesthesia. Two years later, she presented with sudden onset of dysphonia 3 days after another vaginal delivery with spinal and epidural anesthesia; a contralateral VFP was found. Patient 3 noted dysphonia 4 days after knee surgery and was found to have left VFP. No patient had undergone intubation, and none had a central line on the side of the weakness. Imaging ruled out a relevant lesion. All 3 women had evidence of substantial recovery of motion at 6-month follow-up.

Intracranial hypotension resulting in vagal neuropathy is a possible complication of spinal anesthesia and appears to be the cause of transient vocal fold palsy in these 4 cases.