Back pain & loss of co-or...

A 68-year-old man on apixaban presented to the emergency department with back pain following a long-haul flight. Investigations for pulmonary embolus and aortic dissection were negative, and he was discharged with analgesia for mechanical back pain. However, he presented three more times with worsening back pain, the third time with urinary retention and the fourth time with lower limb weakness and loss of coordination. MRI was done.