Study Design: Case report.
Objective: To report a case of quadriplegia after surgery in the prone position for a herniated lumbar disc.
Summary of Background Data: Ischemia in the vascular territories of the vertebral arteries after back surgery in the prone position is rare. Degenerative changes of the cervical spine or decreased blood flow to the head with mechanical vessel obstruction during extreme neck movements, systemic hypotension, and thromboembolism have mostly been implicated in the pathogenesis.
Methods: The case of a 33-year-old man undergoing surgery for an unilateral single level disc herniation at L4-L5 is presented. Within a few hours after surgery he developed quadriplegia and signs of occipital lobe dysfunction. He underwent magnetic resonance imaging investigation. Therapy included arterial blood pressure control, low molecular dextran, dexamethasone, bladder catheterization, and physiotherapy.
Results: Magnetic resonance imaging demonstrated intramedullary ischemic changes in the cervical spinal cord and at the borderline between anterior and posterior circulation. Outcome after 2 years is fair regarding the severe initial deficit-the patient walks alone with a cane and bladder function is under control. He is employed in a sedentary job.
Conclusions: The authors believe that a temporary mechanical occlusion of a vertebral artery led to stasis, formation of thrombi, and subsequent embolism in the vertebrobasilar vascular territory. Extreme head rotation and neck extension is to be avoided in the prone position.