[Traumatic spinal subarachnoid hematoma presenting with Brown-Séquard syndrome].

We report a rare case of traumatic spinal subarachnoid hematoma with Brown-Séquard syndrome following hyperextension injury. A 43-year-old man was admitted to our hospital four days after hyperextension cervical injury complaining of nuchal pain, left hemiparesis and dysesthesia of the left arm. On the third hospital day, neurological examination revealed left C2,3 level Brown-Séquard syndrome. High cervical plain CT scan showed a high density area in the left spinal canal from C1 vertebral body level to C2-3 intervertebral level. Emergency operation was performed and a left-sided subarachnoid hematoma was removed. The left C2 and C3 nerve roots were markedly stretched and the cord was shifted to the right. Neither vascular abnormality nor tumor was found and no traumatic change was seen on the cord. The Brown-Séquard syndrome disappeared soon after surgery, but the weakness of the left arm and anesthesia at the level of left C2 dermatome remained until six months after operation. Review of the literature revealed no such a case as the one in which the patient developed a spinal subarachnoid hematoma following hyperextension injury without any preexisting disease or injury of the spine. Brown-Séquard syndrome caused by spinal subarachnoid hematoma was not found on the literature either. So we believe that this is the first report of case of such lesion. The mechanism of subarachnoid clot formation on hyperextension injury may be due to transient dislocation of the spine with tearing of the anterior longitudinal ligament or to crushing of the cord between the ligamentum flavum, which bulged forward on hyperextension, and the posterior aspect of the vertebral body.(ABSTRACT TRUNCATED AT 250 WORDS)