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 32-year-old man was admitted to the emergency room with a history of sudden headaches, vomiting, and drowsiness. His past medical history showed arterial hypertension. On neurological examination, he was confused without localized neurological deficits. A computerized tomography (CT) scan showed a dense subarachnoid hemorrhage (SAH) with blood in the fourth ventricle. He underwent a digital angiography, which revealed a 6 mm fusiform SCA aneurysm without other signs of vascular dissection [].\nThe patient underwent surgery on the 15th post-hemorrhage day. He was positioned in park bench. A lumbar catheter was inserted and the cerebrospinal fluid (CSF) was drained to induce brain relaxation. A right subtemporal approach was performed, starting with a straight incision over the parietal branch of the STA. This artery was then dissected 10 cm from subcutaneous tissue under microscopic assistance. The temporal muscle was incised and a basal temporal craniotomy was performed. At that time, the lumbar drain was opened and 20 ml of CSF was drained. After a gentle lifting of the temporal lobe, the perimesencephalic cisterns were visualized and opened widely. The cerebellar tent was then incised. A fusiform dilatation of the SCA was observed between the anterior and lateral mesencephalopontine segments. The perforator arteries to brainstem were visualized proximal and distal to the aneurysm. A segment of the artery distal to the aneurysm that did not have perforator arteries was identified as the location for the anastomosis. The STA was then prepared for a terminolateral anastomosis. Temporary clips were positioned in the SCA segment and this artery was then opened and cleaned with heparin solution. Anastomosis was then performed in 40 min with 10-0 nylon single stitches. At the end of the procedure, the temporary clips were opened in a sequential manner. The patency of the anastomosis was confirmed by a micro-Doppler probe. Finally, aneurysm trapping was performed.\nThe patient had an unremarkable recovery and was discharged on postoperative day 7, with a prescription for 100 mg aspirin daily. The postoperative angiogram showed the patency of the bypass, with an excellent filling of the distal SCA segments from the bypass and total aneurysm exclusion [].