Postoperative transient tetraplegia in two patients caused by cervical spondylotic myelopathy.

We report two patients with cervical spondylotic myelopathy following non-cervical spine surgery. These cases revealed postoperative transient tetraplegia with respiratory insufficiency despite optimal anaesthetic management. Both patients showed no limitation of their neck movement at pre-operative airway examination. In addition, their necks had never been overextended during anaesthesia including tracheal intubation. However, postoperative magnetic resonance imaging showed cervical spondylotic myelopathy. Cervical disc herniation and protrusion of a hypertrophic ligamentum flavum caused spinal canal cord compression, and, these may lead to tetraplegia and phrenic nerve impairment. Their muscle weakness gradually improved and completely recovered the following morning. We should consider the existence of cervical spondylosis in the elderly patients over the age of 60 years.