[Impact of ligation of vertebral artery on function of central nervous system, an experimental study].

OBJECTIVE

To study the impact of ligation of bilateral vertebral arteries on the function of central nervous system.

METHODS

Twenty dogs underwent ligation of bilateral vertebral arteries at the level of C4 approximately C5 and then were divided into 4 groups, 5 in each: E1 group (killed in one day after the operation), E7 (killed on the 7(th) day postoperatively), E28 (killed on the 28(th) day postoperatively), and control group. Scoring of the function of central nervous system was conducted after awakening from anaesthesia and before being killed according ro modified Tarlov method. Cortical somatosense evoked potential (CSEP), and motor evoked potential (MEP) were examined by electromyograph. CT, MRI, and magnetic resonance angiography (MRA) of the cervical vertebrae were conducted before the dogs were killed. Histological examination of the spinal cord and brain was made and microangiography was performed.

RESULTS

The myodynamia, gait, and reflex returned to normal 2 approximately 3 days after the operation with the Tarlov score of 6 for all dogs. Imaging examination and histological examination showed no abnormality, including ischemic injury in posterior inferior lobe of cerebellum.

CONCLUSION

Internal carotid artery compensates for the blood obstruction of the vertebral artery in a short time. Cerebral ischemia caused by compression of the vertebral artery is not the main pathomechanism of cervical spondylotic arteriopathy. Microcirculation of human cervical cord can be mimicked in dog model segmentally.