Coffman Stephanie A, Singh Jasmeet, Wolfe Stacey, Fargen Kyle M
Department of Neurosurgery, Wake Forest Baptist Medical Center, Winston Salem, USA.
Interv Neuroradiol. 2018 Dec;24(6):718-721. doi: 10.1177/1591019918787161. Epub 2018 Jul 5.
A woman in her thirties with intracranial hypertension underwent stenting of the right transverse-sigmoid (TS) junction with resolution of the pressure gradient. Due to persisting symptoms at follow-up, she underwent a repeat study showing a patent right TS stent but the non-dominant left transverse sinus, patent on initial studies, was now completely occluded. According to the positive feedback loop hypothesis, stenting of the right transverse sinus should have resulted in a reduction in intracranial pressures (confirmed by post-stenting lumbar puncture), but also an increase in left transverse sinus diameter, opposed to the occlusion seen on venography. This unexpected finding can be explained by the positive feedback loop hypothesis if a revision is made accounting for intramural venous pressures as an opposing force of venous sinus stenosis, as venous outflow obstruction in the dominant venous sinus pathway provided an increased intramural venous pressure in the non-dominant sinus facilitating patency against extramural pressures.
一名患有颅内高压的三十多岁女性接受了右横窦-乙状窦（TS）交界处支架置入术，压力梯度得以缓解。由于随访时症状持续存在，她再次接受检查，结果显示右TS支架通畅，但初次检查时通畅的非优势侧左横窦现已完全闭塞。根据正反馈回路假说，右横窦支架置入术本应导致颅内压降低（支架置入后腰穿证实），同时左横窦直径增加，这与静脉造影显示的闭塞情况相反。如果对壁内静脉压进行修正，将其视为静脉窦狭窄的反作用力，那么这一意外发现可以用正反馈回路假说解释，因为优势静脉窦通路中的静脉流出道梗阻会使非优势窦内的壁内静脉压升高，有助于抵抗壁外压力维持通畅。
