Spinal meningeal diverticula in spontaneous intracranial hypotension: analysis of prevalence and myelographic appearance.

BACKGROUND AND PURPOSE Spinal meningeal diverticula have been implicated in the pathogenesis of spontaneous intracranial hypotension and have been proposed as both diagnostic features of and therapeutic targets for the condition. We compared the prevalence and myelographic appearance of spinal diverticula in patients with SIH and healthy controls. MATERIALS AND METHODS Patients satisfying the ICHD-2 criteria for SIH were retrospectively identified. CT myelograms of 19 patients with SIH were compared with CT myelograms of 18 control patients. Images were reviewed by 2 blinded neuroradiologists. The prevalence, morphology (round versus multilobulated), size, and location (cervical, upper thoracic, lower thoracic, or lumbar) of spinal meningeal diverticula were analyzed. RESULTS There was no difference in the proportion of patients with diverticula in the SIH group compared with the control group (68% versus 44%, P = .14) or in the mean number of diverticula per patient (6.3 versus 2.2, P = .099). No difference was seen in the morphology (P = .95) or size (P = .71) of diverticula between groups. There was a difference between groups that just reached statistical significance (P = .050) in the location of the diverticula along the spinal axis, but substantial overlap was seen between groups for all spinal locations. CONCLUSIONS Despite the well-established association between spinal meningeal diverticula and SIH, we found no difference in the prevalence or myelographic appearance of diverticula in patients with SIH compared with controls. Further investigation into the role of diverticula in the diagnosis and treatment of SIH is necessary.