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 56-year-old male patient came to the emergency room due to a right-sided occipital headache and vertigo, which suddenly began three days before the visit, and a symptom of tilting to the right, which began one day before the visit. There was no history of an external injury within the past one week. The patient did not have any underlying diseases, history of migraines, or risk factors for stroke, except for smoking. He also did not have a history of taking antiplatelet agents. When the patient visited the emergency room, his blood pressure was 160/100 mmHg, the pulse rate was 62/min, breathing rate was 19/min, and body temperature was 36.5 °C. The results of a neurological examination showed lateropulsion to the right side, hypoesthesia on the right side of the face, ataxia in the right upper and lower limbs, and the NIH stroke scale was 2. The results of serological studies and electrocardiography were normal.\nThe diagnosis was determined to be an acute ischemic stroke because the diffusion weighted imaging (DWI) of MRI revealed a high signal intensity area in the right lateral medulla. CT angiography (CTA) was taken first at 3 days after the symptom occurred. HR vw-MRI was taken a day after (at the 4th-day). The right PICA was not observed in the first CTA, and partial spontaneous recanalization was observed on the time-of-flight MR angiography (TOF-MRA), which was taken one day after. Moreover, the sagittal 3D T1 weighted HR vw-MRI showed a T1 hyperintense intramural hematoma in the right proximal PICA (Fig. ). However, a T2 weighted 3D curved MPR image revealed the luminal dilation and intimal flap in the right proximal PICA (Fig. ). The patient was diagnosed with spontaneous isolated PICA dissection on the basis of the neurological symptoms and imaging. He was treated with antiplatelet agents and the neurological symptoms of the patient improved during course of admission.