Supplementary Material for: Cerebral Venous Thrombosis Causing Posterior Fossa Lesions: Description of a Case Series and Assessment of Safety of Anticoagulation

Background: Isolated posterior fossa parenchymal lesions associated with cerebral venous thrombosis (CVT) are rare. Posterior fossa lesions are an independent predictor of death in CVT. We aim to describe the characteristics and outcome of patients with CVT and isolated posterior fossa lesions and assess the safety of anticoagulation in patients with posterior fossa lesions associated with CVT. Methods: We retrieved data from all patients with posterior fossa parenchymal lesions in the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT) cohort related to clinical features, therapy and outcome. Fisher's exact test was used to evaluate associations. To assess the safety of anticoagulation in CVT patients with posterior fossa lesions we considered all patients with a lesion in this topography, either isolated or with concomitant supratentorial lesions, and compared the rate of new intracranial haemorrhages on repeated imaging with the remaining cohort. Results: Out of 624 patients, 12 had isolated posterior fossa lesions and 14 had posterior fossa lesion with accompanying supratentorial lesions. The lateral sinus was most frequently occluded (n = 11). Involvement of the superior sagittal sinus was significantly less frequent compared to the remaining patients of the cohort (p = 0.013). None of the patients with isolated posterior fossa lesion died but 3 remained dependent on follow-up. Poor outcome (modified Rankin Scale ≥3) was more frequent in patients with any posterior fossa lesion, even when on anticoagulation (29.2% vs. 11.9%; OR 3.04; 95% CI 1.2-7.6; p = 0.018). Of the 24 anticoagulated patients with a posterior fossa lesion, 3 (12.5%) had new haemorrhages on repeated imaging, compared with 30 out of 495 anticoagulated patients (6.1%) without posterior fossa lesions (p = 0.19). Conclusions: We describe the largest series of CVT patients with associated posterior fossa lesions. When compared to anticoagulated CVT patients without posterior fossa lesions, CVT patients with posterior fossa lesions on full anticoagulation did not have a significant increase in the rate of new intracranial haemorrhages.

背景：伴随脑静脉血栓形成（cerebral venous thrombosis, CVT）的孤立性后颅窝实质病变较为罕见。后颅窝病变是CVT患者死亡的独立预测因素。本研究旨在描述合并孤立性后颅窝病变的CVT患者的临床特征与预后，并评估合并后颅窝病变的CVT患者接受抗凝治疗的安全性。
方法：我们从国际脑静脉和硬脑膜窦血栓形成研究（International Study on Cerebral Vein and Dural Sinus Thrombosis, ISCVT）队列中提取所有合并后颅窝实质病变患者的临床特征、治疗方案及预后相关数据。采用Fisher确切概率法评估变量间的关联。为评估合并后颅窝病变的CVT患者抗凝治疗的安全性，我们纳入所有存在该部位病变的患者（无论病变为孤立性还是伴随幕上病变），并将其随访影像学检查中新发颅内出血的发生率与队列中其余患者进行对比。
结果：在624例患者中，12例为孤立性后颅窝病变，14例合并后颅窝病变及幕上病变。横窦是最常见的闭塞静脉窦（n=11）。与队列其余患者相比，上矢状窦受累的发生率显著更低（p=0.013）。孤立性后颅窝病变患者无死亡病例，但3例患者随访期间仍需依赖他人照料。无论是否接受抗凝治疗，合并任意后颅窝病变的患者预后不良（改良Rankin量表≥3分）的发生率均更高（29.2% vs. 11.9%；比值比（odds ratio, OR）=3.04；95%置信区间（confidence interval, CI）1.2~7.6；p=0.018）。在24例接受抗凝治疗的后颅窝病变患者中，3例（12.5%）在随访影像学检查中出现新发颅内出血，而495例未合并后颅窝病变的抗凝治疗患者中仅30例（6.1%）出现新发颅内出血（p=0.19）。
结论：本研究报道了目前最大样本量的合并后颅窝病变的CVT患者队列。与未合并后颅窝病变的CVT抗凝患者相比，接受足量抗凝治疗的合并后颅窝病变的CVT患者，其新发颅内出血的发生率并未出现显著升高。