Diagnosis
10What is dementia with Lewy bodies?
Plain-language primer on dementia with Lewy bodies, why it is different from Alzheimer's, and how modern care works.
What is chronic inflammatory demyelinating polyneuropathy?
Plain-language primer on CIDP, why immune therapy is the foundation, and what the modern options can offer.
What is spasticity?
Plain-language primer on spasticity, why it happens after neurological injury, and what the therapy options can offer.
Acute ischemic stroke explained
Plain-language primer on acute ischemic stroke, why time matters, and how modern therapy works.
What are CSF biomarkers, and how do they fit alongside plasma and PET?
CSF biomarkers - measured in cerebrospinal fluid obtained by lumbar puncture - are well-validated tests for Alzheimer's pathology that pre-date both plasma biomarkers and broad amyloid PET access. They remain in routine clinical use, particularly where PET is not available and where the diagnostic question is complex enough to warrant the procedural friction.
What is tau PET, and how is it different from amyloid PET?
Tau PET is a brain scan that shows the build-up of tau, the second protein associated with Alzheimer's disease. The image is closer to the clinical picture than amyloid is - tau accumulation tracks more directly with where and how a person is currently impaired. The trade-off is that tau PET is harder to access than amyloid PET, and the access gap is now a rate-limiter on multiple fronts.
What is mild cognitive impairment, and how is it different from "early Alzheimer's"?
Mild cognitive impairment (MCI) is a diagnostic category, not a disease. It describes cognitive decline that is more than expected for age but not severe enough to count as dementia. When that decline is caused by underlying Alzheimer's pathology, the term you will increasingly hear in clinical-trial and treatment settings is "early Alzheimer's disease" - which means MCI due to Alzheimer's plus mild dementia due to Alzheimer's, taken together.
What is co-pathology in dementia, and why does it matter?
Co-pathology means more than one disease process is contributing to someone's symptoms at the same time. In older patients with cognitive symptoms, mixed pathology is the rule, not the exception.
What is amyloid PET, and when is it used?
Amyloid PET is a brain scan that shows whether the amyloid protein associated with Alzheimer's disease has built up in the brain. It is used to confirm or rule out Alzheimer's pathology when the diagnosis matters.
What are plasma biomarkers in Alzheimer's disease?
Plasma biomarkers are blood tests that look for proteins associated with Alzheimer's disease pathology. The most clinically useful one in 2026 is plasma p-tau217.
Treatment
7What are GLP-1 receptor agonists, and why are they being tested in Alzheimer's?
GLP-1 receptor agonists are a class of drugs originally developed for type 2 diabetes and now widely used for obesity. The class is now in late-stage Alzheimer's trials. The mechanistic case spans metabolic, vascular, inflammatory, and direct neuronal pathways - and the access shape would be very different from anti-amyloid therapy.
What is a subcutaneous anti-amyloid antibody, and why does it matter for access?
Subcutaneous formulations of the anti-amyloid antibodies are reformulations that allow the same active drug to be given as a small under-the-skin injection rather than an intravenous infusion. The biology is the same. The delivery is dramatically simpler. The access implications are real but partial - subcutaneous administration removes the infusion-chair constraint, but does not change the MRI surveillance requirement.
What is iADRS, and how is it different from CDR-SB?
iADRS - the Integrated Alzheimer's Disease Rating Scale - is a composite endpoint that combines a cognitive score (ADAS-Cog) with a functional score (ADCS-iADL) into a single number. It is the primary endpoint donanemab used in its pivotal trial and is reported alongside CDR-SB in many late-stage Alzheimer's programs. It answers a slightly different question than CDR-SB does.
What is CDR-SB, and what does a small change on it actually mean?
CDR-SB is the Clinical Dementia Rating - Sum of Boxes, the cognitive and functional scale used as the primary endpoint in most late-stage Alzheimer's trials. It is a six-box, 0–18 scale, scored by a clinician from a structured interview with the patient and a caregiver.
What is Medicare coverage with evidence development?
Coverage with evidence development (CED) is a Medicare coverage mechanism that pays for a treatment on the condition that clinical data about its use is collected and reported back to CMS. It is how Medicare currently covers anti-amyloid antibodies.
What is ALZ-NET, and what does it do with patient data?
ALZ-NET is the Alzheimer's Network for Treatment and Diagnostics - the main patient registry collecting real-world data on people receiving anti-amyloid therapy in the US. It is the registry that Medicare's coverage-with-evidence-development framework routes patients through.
What are anti-amyloid antibodies, and how do they work?
A plain-language explanation of the disease-modifying drug class that defines the current Alzheimer's treatment landscape.
Safety
2What ARIA is, and why it gates how anti-amyloid antibodies can be used
ARIA - amyloid-related imaging abnormalities - is the side effect that defines the operational and clinical experience of being on lecanemab or donanemab. Understanding what it is, who it affects more, and why it requires MRI surveillance is essential context for any conversation about anti-amyloid treatment.
What is ARIA, and why does it matter for treatment?
Amyloid-related imaging abnormalities are the defining safety consideration of the anti-amyloid antibody class - and the reason MRI surveillance is built into treatment.