Spinal imaging findings in spontaneous intracranial hypotension

OBJECTIVE. spontaneous intracranial hypotension is a syndrome of postural headaches that arises as a result of CSF leakage and without previous lumbar puncture. The purpose of this study was to review and describe the spinal imaging findings of this entity. MATERIALS AND METHODS. The spinal MRI and CT myelographic imaging findings of 13 patients with spontaneous intracranial hypotension were retrospectively reviewed. Spinal images were evaluated for spinal fluid collections, dural enhancement, dilated epidural veins, a thickened or enlarged ventral lateral epidural venous plexus, high T2 signal intensity between the spinous processes of C1 and C2 (C1-C2 sign), structural abnormalities, canal attenuation or cord compression, and active contrast extravasation. When available, brain MRI findings were reviewed. Surgical correlation was made in the cases of four patients. RESULTS. The patients were found to have spinal fluid collections (11 of 13 patients), dural enhancement (eight of 10 patients undergoing contrast administration), dilated epidural veins (10 of 13 patients), an enlarged epidural venous plexus (nine of 13 patients), C1-C2 sign (seven of 13 patients), structural abnormalities (four of 13 patients), canal attenuation or cord compression (five of 13 patients), and active contrast extravasation (four of 13 patients). CONCLUSION. Spinal imaging is likely to show one or more findings in patients with spontaneous intracranial hypotension and may be of particular value to patients with equivocal clinical or brain imaging findings and patients who need surgery. Encountering these findings on spinal images may suggest the diagnosis of spontaneous intracranial hypotension and therefore can influence patient treatment.