case_images: PMC5445656_01
case_images: A 47-year-old man with a one-month history of dysarthria showed isolated left hypoglossal nerve palsy (a), which was improved significantly three months after microvascular decompression (b)
case_images: SNI-8-74-g001.jpg
case_images: PMC5445656_01_SNI-8-74-g001.jpg
case_images: F1
case_images: Neurological examination revealed isolated left HNP [Figure 1a]. At a 3-month postoperative follow-up, he exhibited improvement of hypoglossal nerve palsy without lower cranial nerve dysfunction [Figure 1b].
case_images: MRI (CISS, constructive interference in steady state) images of the present case. Left hypoglossal nerves (black thin arrows) originated from the ventral side of the medulla oblongata, which is composed of two bundles, and ran into the hypoglossal canal (black thick arrows) beyond the left VA (white thin arrow). It is easy to detect when compared with the contralateral side (arrow head)
case_images: SNI-8-74-g002.jpg
case_images: PMC5445656_01_SNI-8-74-g002.jpg
case_images: F2
case_images: Magnetic resonance imaging (MRI) (CISS, constructive interference in steady state) revealed left hypoglossal nerve compression by the V4 segment of the left atherosclerotic VA [Figure 2].
case_images: Multiple aneurysms including a partially thrombosed large left MCA saccular aneurysm and a fusiform aneurysm at the left PICA were revealed. The left VA was also dilated and winding
case_images: SNI-8-74-g003.jpg
case_images: PMC5445656_01_SNI-8-74-g003.jpg
case_images: F3
case_images: This finding strongly suggested that the hypoglossal nerve was compressed by the left VA [Figure 3].
case_images: The left vertebral artery compressed the hypoglossal nerve from the deep side of the surgical field to the superficial side. Hypoglossal nerves were stretched by the left VA and became extremely thin (a). The left VA was moved anteriorly and attached to dura using a polytetrafluoroethylene (Teflon ) sheet and fibrin glue. Hypoglossal nerves were released (b)
case_images: SNI-8-74-g004.jpg
case_images: PMC5445656_01_SNI-8-74-g004.jpg
case_images: F4
case_images: The left hypoglossal nerve became free from compression after the procedure [Figure 4a and 4b].