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 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. ).