Ruptured basilar artery perforator aneurysm (BAPA) is a rare cause of subarachnoid hemorrhage (SAH) and is difficult to diagnose.

A 60-year-old male was rushed to our hospital due to severe headache. Computed tomography (CT) showed diffuse SAH, and 3-dimensional CT angiography (CTA) showed a saccular aneurysm in the left anterior cerebral artery (ACA), which was treated with clipping. However, intraoperative findings showed little SAH around the aneurysm and neither a rupture point nor a white thrombus on the aneurysm. Postoperative CT showed a marked decrease in SAH in the prepontine cistern, and digital subtraction angiography (DSA) showed disappearance of the ACA aneurysm and no other lesions. SAH in the prepontine cistern re-increased on CT on the 6th postoperative day, when CTA failed to show the cause. On the 12th postoperative day, CT showed further increased SAH in the prepontine cistern, and DSA revealed a BAPA. Stent-assisted coil embolization was planned at the chronic phase, but the patient went into cardiac arrest the next day, presumably due to a third re-rupture of the BAPA.

The coexistence of a ruptured BAPA and an unruptured saccular aneurysm is extremely challenging in terms of both diagnosis and treatment strategy.

Primary immune thrombocytopenia (ITP) paradoxically carries a high risk of developing thrombosis. However, the efficacy of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) in ITP patients remains unclear due to its rarity.

A 47-year-old female treated for chronic ITP for 2 years was admitted to the hematology department with severe thrombocytopenia. The patient was started on glucocorticoid therapy, and her platelet count rose soon. On sixth day of hospitalization, she suddenly presented with loss of consciousness, conjugate eye deviation to the left, and left hemiplegia. Magnetic resonance imaging and angiography showed an acute ischemic lesion with the left M1 occlusion. Emergent MT was performed and resulted in successful recanalization. Postoperatively, she recovered consciousness and was able to follow instructions. However, on the third day after MT, the patient suffered hemorrhagic infarction and brain herniation, and decompression craniectomy was performed. Her consciousness slowly recovered, and cranioplasty was performed after brain swelling improved. The patient was transferred to a rehabilitation hospital with modified Rankin Scale (mRS) 4 on 84th day of hospitalization, and eventually improved to mRS 3 with motor aphasia and right hemiparesis.

MT may be effective for AIS in ITP patients with appropriate case selection.