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 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 [].