Confusion after spine injury: cerebral fat embolism after traumatic rupture of a Tarlov cyst: Case report

We report a 70-year-old man with an 8-month history of left posterior thigh and leg pain who had sudden confusion after a fall from standing. It was due to cerebral fat embolism suspected by computed tomography scan, later confirmed by brain magnetic resonance imaging (MRI). A spinal MRI scan was then performed and revealed a sacral fracture which drained into an unknown perineurial cyst (Tarlov cyst). Under medical observation the patient fully recovered within three weeks.Sacral perineurial cysts are rare, however they remain a potential cause of lumbosacral radiculopathy.In Emergency Care, patients admitted for low back pain with or without sciatica are common. Specific aetiology of low back pain is rarely found and does not need routinely imaging exploration [1]. But if physical examination is abnormal or pain unusually persistent, Emergency Physician should explore the lumbar spine with a CT or MRI scan. These imaging techniques can reveal herniated disk, spinal stenosis, early spinal infection or tumour. Nevertheless other rare causes can occur as in our observation where we report a sacral fracture of an unknown Tarlov cyst complicated with cerebral fat embolism.A 70-year-old man with an 8-month history of left posterior thigh and leg pain was admitted to our Emergency Department after a fall during a gym session. He presented with a moderate pelvic and head trauma. A physical examination showed only tenderness upon palpation and percussion of the lumbar and sacral spine. Plain radiographic examinations of spine, pelvis and chest were interpreted as normal. The patient had no medical or surgical history other than essential hypertension. A few hours after admission, he became very confused and agitated. A cerebral computed tomography scan did not show either vascular lesion or cerebral contusion but fat droplets in the lateral ventricles (Figure 1A). A further investigation with CT scan of the spine revealed a fractured sacrum extending into a ruptured perine