A 39 year-old male without past notable medical history was admitted with a sudden headache and neck stiffness. Brain computed tomography (CT) demonstrated evidence of Fisher Grade III subarachnoid hemorrhage (SAH) predominance of the pre-pontine, left ambient and quadrigeminal cistern (), and a fusiform aneurysm of a left distal SCA was revealed on the CT angiography (). Subsequent digital subtraction angiography (DSA) revealed the fusiform dilatation (12 mm length; 4.5 mm width) involving the ambient segment of the left distal SCA. The left SCA was duplicated ahead of the aneurysm and there was sufficient collateral circulation from the ipsilateral anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) (). The aneurysm was treated by endovascular occlusion of the aneurysm sac and the involved branch. Under general anesthesia an Excelsior SL-10 microcatheter was used to access the aneurysm. Seven detachable platinum coils were used to obliterate the lesion. Post-procedural angiography showed complete occlusion of the aneurysm sac and involved the SCA branch (). There was no immediate complication after embolization. Diffusion MRI was done 8 hours after embolization. MRI revealed scattered high signal change on the left posterior tegmentum, superior vermis, and superior part of the left cerebellum (). Left sixth nerve palsy occurred in the patient 1 day after EVT. The symptom completely recovered within 1 week of the post-procedural period. No neurological deficit was seen during the clinical 3-month follow-up.
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.