A 70-year-old woman with hypertension, hyperlipidemia, and a history of smoking presented with a peripheral fusiform SCA aneurysm found incidentally during a routine MRI investigation due to “black out” symptoms. The aneurysm was located 2 cm from the SCA origin, and measured 7 mm in maximal diameter [Figure and ]. After a thorough discussion of treatment options, the patient elected to undergo a combined subtemporal, presigmoidal approach. On the lateral aspect of the brainstem, the aneurysm was exposed along with the parent artery and two major efferent branches. One of these branches, the largest one, was superiorly directed and a double, smaller branch, presented inferiorly around the aneurysm fundus. It was necessary during microsurgical dissection to detach the aneurysm dome from the tentorial undersurface as well as from the 4th cranial nerve. Multiple clips were used to reconstruct the aneurysm without intra-operative complication. Intra-operative angiogram confirmed reconstruction of the fusiform aneurysm with preservation of distal flow [Figure –]. The patient tolerated the procedure well and was extubated and returned to the intensive care unit in stable condition. She was discharged home on the fourth post-operative day without new deficit.
A 52-year-old woman suddenly experienced vertigo and vomited while cleaning her bathtub at home and was subsequently transferred to our hospital by an ambulance. Head CT showed no abnormal findings, thus she was admitted under the suspicion of acute drug poisoning by a detergent. Although no abnormalities on a physical examination or in laboratory data were observed, her nausea and dizziness persisted. Neurologically, she presented only mild dizziness. MRI was then performed at 4 days after the onset, which showed an acute infarction in the left cerebellar hemisphere (Fig. ). The left VA was poorly visualized on MRA as compared to the right VA (Fig. ). In addition, the external diameter of the left VA on basiparallel anatomic scanning (BPAS) was narrowed, suggesting hypoplasia. The proximal portion of the left PICA was not visualized, and the adjacent distal portion appeared to be dilated on MRA (Fig. ). T1-VISTA showed a high-intensity signal area at the dilated portion (Fig. ). Conventional T1 image was obtained on admission and at 24 days after admission, but no high-intensity area was observed at both time points. Cardioembolic causes were excluded by echocardiography and 24-hour electrocardiography. According to these findings, Ischemic stroke of the cerebellum caused by dissection of the left PICA was diagnosed, and the administration of unfractionated heparin was started. Three days later, the dilated portion was enlarged on MRA, therefore, we discontinued unfractionated heparin administration. Since her blood pressure was not high, we even didn’t use antihypertensive treatment. At 8 days after the onset, cerebral angiography demonstrated the “pearl and string sign” at the proximal portion of the left PICA (Fig. ). Dilatation gradually normalized on MRA and the high-intensity signal area on T1-VISTA gradually reduced and disappeared at 4 months after the onset (Fig. ).