An 18-year-old-man was referred to the Neurology Department complaining of headache and double vision. The headache was exquisitely sensitive to postural changes, being completely abolished by lying at. Neurological examination revealed an isolated right sixth nerve palsy. Some 5 weeks previously he had been seen in the Emergency Department of his local hospital after being assaulted with a screwdriver, leading to a penetrating injury of the back at the level of the ninth thoracic vertebra. A plain X-ray was performed and the attending doctor removed the screwdriver. Three days after this injury he represented to the same hospital complaining of sudden onset of headache and vomiting. A diagnosis of migraine was made and he was discharged the next day. The headache persisted and 10 days later he represented because of double vision, mued hearing, mild neck stiness and photophobia, at which time the neurological referral was made. Computed tomography (CT) of the brain on this occasion was normal except for a dilated straight sinus (Fig. 1). A lumbar puncture was not performed. There was no signi®cant past medical history. Brain MRI was performed 4 weeks after injury. The T2-weighted axial images showed dilatation of the dural venous sinuses (Fig. 2a) and the proton density-weighted axial images revealed small subdural and subtentorial collections which were of a higher signal than CSF (Fig. 2b). A sagittal T1-weighted image showed the cerebellar tonsils at the foramen magnum, and post gadolinium-DTPA enhanced coronal T1-weighted images showed homogeneous dural enhancement (Fig. 2c). A diagnosis of probable intracranial hypotension was made and, due to the penetrating nature of the trauma, MRI of the spine was performed. A marker was placed at the site of the skin wound. Sagittal T2-weighted fat-saturated images revealed bright signal posterior to the thecal sac and no evidence of cord injury (Fig. 3a). Axial T2-weighted fat-saturated images showed the spinal cord surrounded by a reduced volume of CSF and an extradural uid collection, the same signal as CSF (Fig. 3b). From this imaging it was concluded that there was a traumatic dural CSF leak causing symptomatic intracranial hypotension. Since the patient had not improved with conservative management, an autologous epidural blood patch was performed, at the site of penetrating injury, and his symptoms resolved completely.
