The only ischemic lesion inside the vascular territory of the probe occurred in the left frontal lobe of patient 1 (T2-weighted image of brain MR scan). The patient suffered from aneurysmal subarachnoid hemorrhage with subsequent severe vasospasm. The lesion resembles a small demarcated lacunar infarct (arrow). The most likely cause of ischemia in this patient was either vasospasm or an embolic lesion secondary to an angiographic intervention. However, it remains unclear, whether it was related to the introduction of the probe itself or represents a true ischemic lesion