Aneurysms of the communicating segment of the internal carotid artery with posterior communicating artery agenesis are associated with perforator infarction after embolization.

BACKGROUND: While anatomic features associated with the risk of posterior communicating artery (PcoA) occlusion after embolization of aneurysms of the PcoA segment of the internal carotid artery (ICA) are well known, the link between perforator origin and perforator infarction has only been reported following neurosurgical clipping. The aim of this study was to determine the origin of anterior thalamic perforators and correlate it with risk of perforator infarction after embolization of PcoA segment aneurysms. METHODS: One-hundred-and-ninety consecutive patients treated for PcoA segment aneurysms between 2017 and 2019 were included. PcoA and anterior thalamic perforator origin anatomy was assessed with computed tomography (CT) angiography, digital subtracted angiography, and high-resolution three-dimensional rotational cone-beam CT angiography (CBCT-A) by two independent interventional neuroradiologists. The presence of perforator infarction after embolization was ascertained from the patient's notes and follow-up imaging. RESULTS: CBCT-A was superior in demonstrating the origin of perforators (P<0.001). The prevalence of perforator origin was estimated at 86% (95% CI 81%-92%) for PcoA, 8% (95% CI 4%-13%) for aneurysm wall, and 5% (95% CI 2%-9%) for ICA. The aneurysm wall origin was exclusively associated with PcoA agenesis, as well as higher risk of perforator infarction after aneurysm coiling compared with other variants (OR=14, 95% CI 2-88, P=0.006). CONCLUSIONS: Our study suggests that anterior thalamic perforators may arise from aneurysm wall when there is no PcoA. Anatomic association between PcoA agenesis and perforator arising from ICA could underlie such findings, and careful consideration is essential before aneurysm repair to anticipate the risk of thalamic infarction in such cases.

Association of spontaneous cerebrospinal fluid rhinorrhea with transverse venous sinus stenosis: a retrospective matched case-control study.

BACKGROUND: A significant proportion of spontaneous cerebrospinal fluid (sCSF) leaks are associated with idiopathic intracranial hypertension (IIH). The aim of this study was to assess the association between sCSF rhinorrhea and transverse venous sinus stenosis (VSS), a feature commonly observed in IIH with a proposed role in its pathophysiology. METHODS: In this single-center, retrospective, matched case-control study, venous and pituitary imaging data of consecutive patients undergoing endoscopic surgery for sCSF rhinorrhea over the last 10 years were retrospectively reviewed. Measurement of the height of the pituitary gland was used to assess empty sella and VSS was quantified as the ratio between the minimal area of the transverse sinus and the cross-sectional area of the sigmoid sinus. VSS was considered significant when it was ≥50% and bilateral. Cases were compared with 1:1 age- and sex-adjusted controls explored for causes other than IIH, intracranial mass effect, or venous thrombosis. RESULTS: Twenty-nine patients were included (median age 56 years, females 69%, body mass index [BMI] 33.8 kg/m2 ). Cases had a significantly lower height of the pituitary gland than controls (2.5 mm vs 6.6 mm, p < 0.001). Bilateral VSS was found in 23 of 29 cases (79%; 95% confidence interval [CI], 65% to 94%) vs 3 of 29 controls (10%; 95% CI, 0% to 21%), with p < 0.001. CONCLUSION: In this retrospective study, sCSF leaks were strongly associated with VSS. This novel finding provides a rationale for further investigation of the role of VSS in the onset of sCSF leaks and of the potential interest in venous stenting after the surgical repair of leaks.