Paroxysmal Nocturnal Hemoglobinuria in ESUS & ETUS

Inclusion Criteria: General: * Participants with embolic ischemic stroke (ESUS), embolic transient ischemic attack (ETUS) or cerebral venous thrombosis (CVTUS) of undetermined source. For transient ischemic attack (TIA): One of the following criteria needs to be fulfilled to be considered as embolic TIA: * Focal symptoms suggesting involvement of de cerebral cortex in the middle cerebral artery (MCA) territory (e.g., aphasia, neglect, apraxia, dystextia, anosognosia, isolated leg, arm or hand weakness). Some of these symptoms have been described as associated with subcortical fibers connecting cortical areas as well but, despite this, they are usually related to cortical localizations. Patients with hemianopia will be included only if hemianopia is not the primary symptom or an isolated symptom. * Rapidly resolving hemispheric symptoms. This concept comprises two components: (a) sudden onset hemispheric syndrome: sudden onset of symptoms and signs implicating extensive ischemia in the internal carotid artery (ICA) or MCA territories, including hemiparesis, hemianopia, conjugate eye deviation, other cortical signs, or altered consciousness; and (b) spectacular shrinking deficit: improvement within 24 hours (approximately). * Symptoms involving more than one vascular territory within a single hemisphere (e.g. left sided weakness + left homonymous hemianopia) or both (e.g., left sided weakness and aphasia in a right-handed patient). * Simultaneous embolization to other orga…