Intracerebral hemorrhage following mild ARIA-H in an APOE ε2 carrier receiving lecanemab

Although APOE ε2 is known to be protective against Alzheimer's disease, it has also been shown to increase risk for hemorrhage with cerebral amyloid angiopathy. This case serves as an opportunity to examine the complex role that APOE ε2 plays in both protection against Alzheimer's disease and contribution to increased hemorrhagic risk with lecanemab.