A 56-year-old woman began to suffer from an occipital headache for 7 days before admission to our hospital, and dizziness appeared 5 days later. On admission, she complained of dizziness and a mild occipital headache. She showed nystagmus and the right nose-finger-nose test was positive. In peripheral blood cell counts and biochemical studies, elevations in white blood cells (9,200/μl) and low-density lipoprotein cholesterol (215 mg/dl) were observed. Coagulation studies and immunological studies were normal. Head computed tomography (CT) showed low-density areas in the right cerebellar hemisphere, diffusion weighted imaging (DWI) of magnetic resonance imaging (MRI) displayed high-intensity signal areas in the cerebellar vermis and the right cerebellar hemisphere (Fig. ). In addition, a high-intensity signal area was observed just adjacent to the right VA on T1-VISTA (Fig. ), whereas no such high intensity was detected on conventional T1 image. Conventional MRA did not depict the right PICA or any abnormal findings of the right VA (Fig. ). Echocardiography and 24-hour electrocardiography showed no findings suggestive of cardioembolic causes. According to these findings, ischemic stroke of the cerebellum induced by the right PICA-D was diagnosed, and after confirming that she had neither hypertension nor aneurysmal formation, combined therapy with clopidogrel and unfractionated heparin administration was started. T1-VISTA showed a slight expansion of the high-intensity area at 3 days after admission, but still no lesions on T1 images. At 9 days after admission, cerebral angiography revealed the “pearl and string sign” at the proximal portion of the right PICA (Fig. ). At 12 days after admission, the patient was discharged with single antiplatelet therapy (clopidogrel). On T1 images, a pale high-intensity area was documented at the dissected lesion at 19 days after admission. Thereafter, the right PICA was gradually depicted on MRA and completely visualized at 5 months after the onset. In parallel with that, the high-intensity signal area on T1-VISTA gradually decreased in size and disappeared by 5 months after the onset (Fig. ). Clopidogrel administration was then stopped.
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.