We report a patient with intracranial hypotension who fell into a coma caused by liquorrhea after thoracic anterior decompression and fusion as a treatment for ossification of posterior longitudinal ligament (OPLL). A 47-year-old female complained of numbness of the bilateral lower limbs and gait disturbance. Images showed OPLL from T4 to T6, which extremely compressed spinal cord. Anterior decompression and fusion were performed after laminectomy and posterior fixation with ISOLA. 12 days after the surgery, headache and dizziness started upon movement. Four weeks later, adding to these symptoms, she showed consciousness disturbance. Computed Tomography (CT) of the brain showed narrow lateral ventricles and bilateral subdural hematomas. CT and X-ray of the chest showed intrapleural effusion on the right. These symptoms and findings suggested intracranial hypotension caused by continuous liquorrhea after surgery. Her conscious level worsened rapidly within 3 days and she fell into a coma. Eemergency surgery was performed to stop liquorrhea with autologous fat, collagen and fibrin glue. Her consciousness level improved gradually and recovered to normal after 5 days. However, pleural effusion was observed for 5 months.
