舌下神经根池段的动脉供应及其与邻近血管的关系

目的]研究舌下神经池段的行程、动脉供应及其与邻近血管的关系。方法]在2 5例脑干标本上原位观察舌下神经根丝的数目、长度、排列方式,舌下神经池段的动脉供应及其与邻近血管的关系。结果]舌下神经从延髓橄榄前沟出脑,舌下神经根丝一般有5条左右,长约10mm ,神经根丝聚集成上、下二束(71.8% )、三束(9.4 % )或扇形(18.8% )。舌下神经池段主要由延髓前外侧动脉、延髓外侧动脉和脑桥外侧动脉发支供应,这些动脉可起自椎动脉、脊髓前动脉、小脑下后动脉和基底动脉或它们发出的穿动脉。椎动脉的90 %行于舌下神经根的腹面,偶尔椎动脉穿舌下神经根上下两束之间或行于舌下神经根丝的背面。小脑下后动脉的5 0 %向后穿舌下神经根丝之间,然后行于舌下神经根的背面。舌下神经与椎动脉发生接触的占74 % ,形成压迫的占18% ,小脑下后动脉与舌下神经发生接触的占2 0 %。结论]舌下神经池段有数条动脉供应,这些动脉主要起于椎动脉或它的分支,舌下神经多与椎动脉接触或被椎动脉压迫,这种接触和压迫可能不是舌下神经麻痹的重要原因。

Artery supply and surrounding neurovascular relationships of hypoglossal nerve root: surgical anatomy of its cisternal segment

Objective To study artery supply and adjacent neurovascular relationships of the hypoglossal nerve root of its cisternal segment. Method] The length, number, arrangements and artery supply of hypoglossal nerve rootlets and the relationship between the nerve root and its surrounding vessels were observed on 25 brain stems. Results] The number of the hypoglossal nerve rootlet is about 5; the length is about 10 mm. The rootlets emerged as two bundles (72%), three bundles (10%), or fan-shaped distribution (18%). The major blood supplies of the cisternal segments of the hypoglossal nerve root were from anterolateral medullary arteries, lateral medullary artery and lateral pontomedullar artery. These arteries arise from vertebral artery, anterior spinal artery, posterior inferior cerebellar artery, basilar artery or their perforating branches. The ventral surface of hypoglossal nerve root was crossed by the vertebral artery (90%), Occasionally, vertebral artery ran between upper and lower bundles or coursed dorsal surface of hypoglossal nerve root. About 50% posterior inferior cerebellar artery ran through upper and lower bundles, then ran upward behind the rootlets of hypoglossal nerve. About 74% of the rootlets of hypoglossal nerve were contacted with vertebral artery, 20% contacting with posterior cerebellar, and 18% were compressed by vertebral artery. Conclusions] The blood supplies of the cisternal segments of the hypoglossal nerves were from several vessels, which mainly arised from the vertebral artery and its branches; rootlets of hypoglossal nerve were contacted or compressed by vertebral artery.