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.
History & examination\nA 31-year-old African-American female with no significant medical history presented with a sudden onset of severe headaches that were highly suggestive of subarachnoid hemorrhage (SAH). The patient was initially evaluated in the emergency department where a neurological examination revealed no deficits.\nPathological findings\nA computed tomography (CT) scan revealed a SAH filling the pre-pontine, crural, ambient, and quadrigeminal cisterns more prominently on the left side of the brain, with mild hydrocephalus (Figure ). A CT-angiography (CTA) showed an enlarged vessel within the left ambient cistern. Digital subtraction angiography (DSA) also revealed the large and irregular appearance of the left SCA in the ambient cistern. No immediate intervention was undertaken.\nThe patient was admitted to the neurosurgical intensive care unit (ICU) and treatment was initiated with regular neurological examinations and daily transcranial-doppler (TCD) studies. The patient remained intact, with TCD values showing only moderate vasospasm. The patient did not require any treatment for the mild radiographic hydrocephalus. On Day 14, the patient underwent a repeat DSA which showed a persistent vasospasm in the distal basilar and bilateral posterior cerebral arteries. Three-dimensional (3-D) reformatting also demonstrated a dissecting fusiform SCA aneurysm in the lateral ponto-mesencephalic segment (Figure ). Due to the persistent vasospasm, no intervention was undertaken at that time as definitive treatment measures were being discussed in a multidisciplinary board meeting.\nEndovascular intervention\nOn Day 21, the patient underwent a successful placement of a low-profile visualized intraluminal support (LVIS Jr.) device (MicroVention, Tustin, CA) covering the fusiform aneurysm, which measured 3-mm wide and 18-mm in length. After premedication with aspirin and clopidogrel, a 7-Fr sheath was inserted into the common femoral artery and a 6-Fr guide catheter was inserted into the left vertebral artery. The left SCA was catheterized using the microcatheter and microguidewire. The LVIS Jr. device was then deployed successfully along the fusiform segment of the SCA without evidence of contrast extravasation. The treatment goal was to preserve the intraluminal flow with flow diversion from the aneurysm for reduction and eventual obliteration.\nPostoperative course\nAt the three-month follow-up, the patient had no complaint and was neurologically intact on examination. A CTA performed at that time showed the SCA patency proximal and distal to the stent without evidence of persistent dilatation or an aneurysm (Figure ). A formal catheter angiogram was deferred by the patient. At the 10-month follow-up, a DSA demonstrated the interval healing of the aneurysm with preserved vessel patency as well as mild distortion caused by the stent in the SCA (Figure ). The patient remained neurologically intact on examination with no complaints.