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 38-year-old male patient came to the emergency room due to vertigo and vomiting that had started suddenly one day before the visit. The patient complained of a left-sided occipital headache that began two days before the visit. He had no history of trauma within 1 week prior to admission. The patient did not have any underlying diseases, history of migraines, or risk factors for stroke except for smoking and alcohol consumption. His blood pressure was 170/100 mmHg, the pulse rate was 70/min, breathing rate was 20/min, and body temperature was 36.5 °C. A neurological examination showed ataxia in the left upper extremity and the NIH stroke scale was 1. The results of serological studies and electrocardiography were normal.\nThe patient was determined to have an acute ischemic stroke because the DWI of MRI showed a high signal intensity area in the left PICA territory. CTA was taken at 2 days after the onset of a headache and at 1 day after the onset of neurological symptoms. Moreover, HR vw-MRI was taken at 6 days after the onset of a headache and at 5 days after the onset of neurological symptoms. Although the left PICA was not observed on the TOF-MRA, other vessels including the left vertebral artery were normal. An intraluminal high signal intensity and mild dilation of the left proximal PICA was revealed on routine 3D HR vw-MRI, but pathognomic signs of dissection was not seen. Curved MPR image reconstructed from 3D T2 weighted HR vw-MRI showed dilation and an intimal flap in the left PICA origin and post dilation stenosis in the left proximal PICA (D). (Fig. ). The patient was diagnosed with spontaneous isolated PICA dissection based on the neurological symptoms and imaging. The patient was treated with antiplatelet agents and discharged after his neurological symptoms improved.