Shlapak, Darya P.

Introduction Spontaneous intracranial hypotension (SIH) caused by a spinal cerebrospinal fluid (CSF) leak classically presents with orthostatic headache. Digital subtraction myelography (DSM) has a well-established diagnostic yield in the absence of extradural spinal collection. At our institution, DSM is followed by lateral decubitus CT myelogram (LDCTM) in the same decubitus position to increase diagnostic yield of the combined study. We evaluated the incremental diagnostic yield of LDCTM following negative DSM and reviewed patient outcomes. Methods Retrospective review of consecutive DSMs with subsequent LDCTM from April 2019 to March 2021 was performed. Combined reports were reviewed, and studies with positive DSMs were excluded. Of the exams with negative DSM, only studies with LDCTM reports identifying potential leak site were included. Interventions and follow-up clinical notes were reviewed to assess symptoms improvement following treatment. Results Of the 83 patients with negative DSMs, 11 (13.2%) had positive leak findings on LDCTMs, and 21 (25.3%) were equivocal. Of 11 positive LDCTMs, 6 leaks were nerve sheath tears (NSTs) and 5 were CSF-venous fistulas (CVFs). 10/11 (90.9%) had intervention and follow-up, with 9/10 (90%) having positive clinical outcome. Of the 21 equivocal LDCTM patients (19 CVFs and 2 NSTs), 15 (71.4%) had interventions and follow-up, with 3/15 (20.0%) with positive clinical outcomes. Conclusion LDCTM following negative DSM has an incremental diagnostic yield up to 38.6%, with up to 14.5% of positive patient outcomes following treatment. LDCTM should be considered after DSM to maximize diagnostic yield of the combined exam.

Background Cerebral venous sinus stenting is an established treatment for patients with idiopathic intracranial hypertension (IIH), refractory to medical management and with stenotic venous sinus on conventional cerebral venography. Currently, there are no clear guidelines on optimal noninvasive imaging modality for routine post-stenting follow-up. We investigated diagnostic yield of CT venography (CTV) for evaluation of stent patency. Methods We reviewed our clinical database of patients with a diagnosis of IIH, who underwent stenting of stenotic transverse or transverse/sigmoid sinus junction. Patients who had follow-up CTVs after more than 30 days were included in the final study group. All CTVs were reviewed by two readers for in-stent thrombosis, extrinsic stent compression, juxta-stent stenosis, and new contralateral venous sinus stenosis. Inter-observer agreement and association of stent patency with clinical outcomes (headache and papilledema) were assessed. Results In all 36 included patients with 38 cerebral venograms for stenting, follow-up CTVs demonstrated adequate opacifications of the venous sinuses and stents for confident evaluation for in-stent thrombosis, extrinsic stent compression, juxta-stent stenosis, and new contralateral venous sinus stenosis, with inter-observer agreement coefficient of 0.7, 1.0, 0.8, and 1.0 respectively. Association between abnormal CTV and higher rates of persistent headache and lower rates of headache improvement/resolution was statistically significant (P-value of 0.01). Conclusion CTV is a reliable noninvasive imaging modality for evaluation of cerebral venous sinuses and stent patency following treatment of idiopathic intracranial hypertension with venous sinus stenting and could be used as a routine follow-up study.