Bilateral medial medullary syndrome following anterior screw fixation of type 2 odontoid fracture, a case report of two patients.

Abstract

Medial medullary syndrome (MMS) has not been reported after anterior screw fixation of an odontoid type 2 fracture. We report on two cases who suffered from an unstable type 2 odontoid fracture following a skiing and a domestic fall accident. Prior to anterior screw fixation surgery both patients presented without neurologic deficits but postoperatively developed a bilateral MMS, including an incomplete tetraparesis, impaired sensation of position and movement as well as tactile discrimination and paralysis of the tongue muscle with deviation to the paralyzed side. MRI showed a typical heart-shaped ischaemic lesion in the medial medulla bilaterally. The search for aetiologic factors was uneventful in both patients except for severe atherosclerosis. Due to the close proximity of the ischaemic area to the surgical site, we here propose the perioperative mechanical manipulation of the upper cervical spine during surgery of patients with atherosclerosis as a new aetiology for MMS.