ARIA surveillance is becoming the rate-limiting step in anti-amyloid care
Amyloid-related imaging abnormalities require protocol-defined MRI at multiple intervals, and managing positive findings demands neurologist judgment that is in short supply.
The MRI schedule, not the infusion schedule, is what most often delays therapy.
ARIA — amyloid-related imaging abnormalities — describes a set of findings (edema, microhemorrhage, superficial siderosis) detected on MRI in patients receiving anti-amyloid antibodies. Most cases are asymptomatic. A minority require treatment pause or discontinuation. A small subset are serious.
Surveillance is mandatory under both the lecanemab and donanemab labels, and the protocol-defined MRI cadence is non-trivial: a baseline plus several follow-ups in the first months of therapy. Health systems that have published their experience consistently flag two issues:
- Imaging slot availability. Routine outpatient MRI in most US health systems is not scheduled around drug-monitoring protocols.
- Interpretation and decision-making. Identifying ARIA on MRI is straightforward; deciding whether to continue, pause, or stop therapy requires neurology judgment that is unevenly available outside specialty centers.
The practical consequence is that ARIA infrastructure — not biology — often determines who can receive therapy and where.
Key sources
- FDA prescribing information — Leqembi and Kisunla, ARIA monitoring sections
- Published health-system anti-amyloid rollout protocols and audits
- Appropriate Use Recommendations for anti-amyloid therapy (Cummings et al.)