PMC6499459_01
Axial CT imaging demonstrates initial cerebellar hemorrhage with extension into the third and fourth ventricles and effacement of the basal cisterns (a and b). Immediate postoperative imaging following suboccipital decompression demonstrates good hematoma evacuation (c), with delayed development of communicating hydrocephalus (d). Immediate postoperative imaging following VP shunt insertion does not demonstrate any adverse findings (e), and delayed imaging is consistent with hemorrhage along the shunt tract (f)
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F1
Computed tomography (CT) of the head demonstrated a large cerebellar parenchymal hemorrhage [Figure 1a, b], but CT angiogram was negative for a vascular malformation, aneurysm, or venous sinus thrombosis. Five weeks following admission, the development of communicating hydrocephalus required the insertion of a VP shunt [Figure 1c, d]. An emergent CT scan demonstrated acute intraparenchymal hemorrhage into the right parietal lobe along the ventriculostomy tract with extensive intraventricular hemorrhage, acute hydrocephalus, and midline shift [Figure 1e, f].
Diagnostic cerebral angiography performed via a right common carotid injection (a: AP; b: lateral; c: lateral zoom) does not demonstrate any aneurysm, arteriovenous malformation, or arteriovenous fistula related to right middle cerebral artery and anterior cerebral artery. Following delayed hemorrhage along shunt tract, right internal carotid injection (d-f) identifies a pseudoaneurysm along the M4 segment of the right middle cerebral artery immediately adjacent to the right parietal ventriculostomy catheter (arrows)
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F2
Subsequent vascular imaging, including magnetic resonance (MR) and digital subtraction angiography was negative for pathology [Figure 2a-c]. An EVD was inserted through the previous right frontal burr hole, and a CT angiogram followed by a four-vessel angiogram revealed a pseudoaneurysm of a right distal middle cerebral artery (MCA) branch immediately adjacent to the entry point of the ventricular catheter in the right parietal region [Figure 2d-f].