A 42-year-old man with no past significant medical illness presented with headache. CT scan done showed subarachnoid hemorrhage (SAH) predominantly in the perimesencephalic cisterns []. Magnetic resonance imaging T1 gradient sequence also showed the hypointense signal suggestive of blood products in the perimesencephalic cisterns []. Fetal posterior cerebral arteries are seen on both the sides arising from the internal carotid artery [Figures and ]. DSA (digital subtraction angiogram) done subsequently revealed fusiform bulbous dilation involving both the cisternal and cortical segments of the left SCA []. Endovascular treatment in the form of parent artery occlusion was done under general anesthesia, with complete exclusion of the aneurysm from the circulation as seen on post-coiling angiogram []. Standard heparin protocol was followed and activated clotting time greater than 250 s was maintained during the procedure. Six-French (6F) Envoy (cordis) guiding catheter was placed in the distal vertebral artery. A combination of echelon-10 microcatheter (ev3) and transcend 0.014 microwire (Stryker) were used to access the aneurysms. Multiple Axium (ev3) coils were used to occlude the aneurysm. There were no intra- and periprocedural complications and patient was discharged on the 5th day after operation. The post-operative course was uneventful. The patient's neurological examination after 1 month was completely normal. Control angiogram done after 1 year showed stable occlusion of the aneurysm with endovascular coil in place [].
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.