"What was I going to say just now?" "Where did I put my glasses?"
These everyday moments of forgetfulness may hide the earliest signs of Alzheimer's disease.
In the past, a diagnosis could only be made when dementia symptoms were evident. Nowadays, with the latest biomarker detection technology, we can detect the early signs of the disease 10-20 years in advance.
In 2024, the American Alzheimer's Association Working Group (AAW) released the "Revised Criteria for the Diagnosis and Staging of Alzheimer's Disease," marking a significant breakthrough in the global field of Alzheimer's disease diagnosis. We are proud to announce that our team at Xuanwu Hospital has taken the lead in applying these criteria to the Chinese Longitudinal Study of Cognitive Decline (SILCODE) cohort.
01 Major diagnostic innovation: from post-dementia diagnosis to preclinical warning
Many people believe that memory decline is a "normal part of aging," but this is not the case. Alzheimer's Disease (AD) is a progressive condition that results from the gradual degeneration and death of brain cells, leading to an inability to manage daily life and work independently.
Traditional diagnostic methods can only confirm the diagnosis after patients exhibit obvious symptoms of dementia, thus missing the optimal intervention period. Nowadays, through molecular imaging technology and biomarker detection, we are able to make a diagnosis in the preclinical stage.
02 Core breakthrough: Blood testing has become a reality, with costs significantly reduced
In July 2025, the Alzheimer's Association International Conference (AAIC 2025) released the first clinical practice guidelines on the use of blood biomarkers for detection, marking a new era in AD diagnosis.
The latest guidelines confirm that a single blood draw is sufficient to test several key indicators (such as p-tau217 and Aβ42/40 ratio), achieving an accuracy rate of over 96%! The cost of blood testing is only 1/5 to 1/10 of that of PET testing.
This breakthrough means that what used to require tens of thousands of yuan for PET CT or cerebrospinal fluid testing can now be accomplished through a simple blood draw test.
03 Four stages: How to predict the progression of Alzheimer's disease
The core innovation of the new standard lies in the establishment of the ABCD staging system, which enables both doctors and patients to clearly understand the stage of the disease.
Stage A (early stage): There is abnormal deposition of Aβ protein, but tau protein has not yet spread. This stage is completely asymptomatic and can only be detected through core 1 biomarker testing.
Stage B (early stage): Aβ positivity with tau protein appearing locally in the medial temporal lobe. The patient may begin to experience mild memory changes.
Stage C (intermediate stage): tau protein spreads to the neocortical regions. Patients may experience mild cognitive impairment and start to feel inadequate in daily life.
Stage D (late stage): tau protein is highly taken up in the neocortex. At this point, patients usually exhibit significant symptoms of dementia.
04 Seven clinical manifestations: from completely normal to severe dementia
In addition to biomarker staging, the new standard also provides a detailed definition of clinical stages 0-6:
Stage 0: asymptomatic and without positive core markers, only with genetic risk genes
Stage 1: Only biomarker abnormalities are present, with completely normal objective cognitive tests
Stage 2: Patients experience a decline in self-perceived memory, but clinical tests remain within the normal range. This stage can last for several years
Stage 3: Objective examination reveals cognitive impairment, but ability to perform daily activities remains normal
Stage 4: Emergence of temporal disorientation, requiring assistance with complex daily activities
Stage 5: Difficulty in orienting to the environment, requiring assistance to complete basic daily activities
Stage 6: Personality orientation disorder, loss of self-care ability, requiring full-time care
05 Preventive intervention: 45% of dementia risk can be reduced through intervention
The focus of Alzheimer's disease lies in prevention and early intervention. The Lancet suggests that controlling 14 major modifiable risk factors can prevent 45% of the risk of dementia:
Adulthood (20-40 years old)
Receive education and accumulate cognitive reserves
Establish a healthy lifestyle: quit smoking, limit alcohol consumption, and maintain a balanced diet
Protect your head to avoid external injuries
Middle age (40-65 years old)
Control the "Three Highs" (hypertension, hyperglycemia, and hyperlipidemia)
Correct hearing loss and treat depressive symptoms
Maintain a body mass index (BMI) within the range of 18.5 to 24.9
At least 150 minutes of moderate-intensity aerobic exercise per week
Old age (over 65 years old)
Maintain social activity and cultivate hobbies
Monitor cognitive changes and conduct regular cognitive assessments
Prevent falls and maintain muscle strength
Adopt the Mediterranean-DASH diet (MIND diet)
06 Therapeutic breakthrough: Early intervention becomes possible
These new drugs bring hope
If you or your family members experience the following conditions, it is recommended to visit a memory clinic or neurology department for consultation:
My memory has noticeably declined compared to my peers, especially in terms of forgetting recent events
Changes in personality, such as becoming suspicious, anxious, and depressed
Executive function decline, such as being unable to do things well that were previously manageable
Language ability declines, and often I can't find the right words
The doctor may suggest the following examinations:
Professional neuropsychological scale assessment
Magnetic resonance imaging (MRI) of the brain (hippocampal volume measurement is important)
APOE gene testing (to assess genetic risk)
Blood biomarker detection (such as p-tau217, Aβ42/40 ratio)
Perform Aβ PET or tau PET examination when necessary (based on actual conditions)
Hainan Chengmei Hospital's Memory Clinic integrates professional resources from multiple fields to provide patients with comprehensive, precise, and personalized diagnosis and treatment services.
Visiting expert
Clinic Hours: Monday morning
Clinic Hours: Wednesday afternoon
Source | WeChat official account of Professor Han Ying's team at Xuanwu Hospital