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. ).
A 60-year-old woman who developed intermittent diplopia underwent MRI scan revealing a tentorial meningioma as well as aneurysms of the posterior communication artery, right vertebral artery, and peripheral superior cerebellar artery. The tentorial meningioma tumor was located in the posterior aspect of the cerebellopontine angle and causing compression of the brainstem along the course of the 4th cranial nerve, and the complex, partially thrombosed dissecting aneurysm of the SCA was situated just proximal to the entry of the 4th nerve into the free edge of the tentorium. Angiography revealed a partially thrombosed wide-necked aneurysm not amenable to endovascular intervention. Microsurgical clipping and simultaneous tumor removal were recommended.\nA combined subtemporal, presigmoidal approach was performed. A wide bone removal of the middle cranial fossa was necessary to reach the tentorial incisura allowing exposure of the tumor. Due to the associated brainstem compression from the tumor, the meningioma was debulked first, and then the aneurysm was addressed. Interestingly, on reaching the SCA there was obvious hemosiderin staining of the arachnoid surrounding the aneurysm dome, indicating a previous rupture. During microsurgical dissection, it was confirmed that this aneurysm was thick-walled and partially thrombosed [Figure and ]. The aneurysm was reconstructed with a single clip placed well up on the aneurysm dome to avoid compromise of the parent artery. Intra-operative angiogram demonstrated complete obliteration of the aneurysm with normal flow through the SCA and distal branches. Post-operatively, apart from transient hyponatremia and hyperglycemia, the patient did well without complication.