case_images: PMC4866054_01
case_images: Pre- and post-operative computed tomography and magnetic resonance imaging scans. (a) Preoperative computed tomography showed a low-density area in the right cerebellar hemisphere and a partly isodense area that was difficult to diagnose. (b and c) Preoperative magnetic resonance imaging (b, T1-weighted image; c, T2-weighted image) showing a subdural hematoma. The intensity is different on these images. (d) Postoperative computed tomography showing removal of the hematoma. (e and f) Postoperative magnetic resonance imaging showing removal of the hematoma (e, T1-weighted; f, T2-weighted)
case_images: SNI-7-255-g001.jpg
case_images: PMC4866054_01_SNI-7-255-g001.jpg
case_images: F1
case_images: Computed tomography (CT) revealed a low- to high-density area in the subdural space of the posterior fossa and narrowing of the fourth ventricle [Figure 1a]. T1-weighted images, it ranged from hypo- to hyper-intense; on T2-weighted images, it was hyperintense. These findings were suggestive of CSH [Figure 1b and c]. CT and MRI studies showed no residual mass effect in the fourth ventricle [Figure 1d-f].
case_images: Operative procedure. (a) A straight skin incision (dotted line) was made for midline bilateral suboccipital craniectomy (black solid line). (b) A V-shaped dural incision was made (dotted line) and the winding occipital sinus was clipped with hemoclips (slanted line). (c) After dural incision, the outer membrane of the chronic subdural hematoma was observed
case_images: SNI-7-255-g002.jpg
case_images: PMC4866054_01_SNI-7-255-g002.jpg
case_images: F2
case_images: With the patient under general anesthesia and in the prone position, we used the midline suboccipital approach and performed bilateral suboccipital craniectomy [Figure 2a]. Intraoperatively, we encountered unexpected bleeding from a single occipital sinus that wound to the right and was well developed [Figure 2b]. The outer membrane of the CSH was observed after dural incision [Figure 2c].