China Longitudinal Aging and Cognitive Impairment Study
This is a multi-center longitudinal study that consists of five cohorts: cognitive normal aging (CN), Subjective cognitive impairment (SCI), mild cognitive impairment (MCI), Alzheimer's disease (AD) and vascular cognitive impairment (VCI). The goals of this study are as follow: 1.To establish longitudinal cohort study database containing comprehensive epidemiological data, neuropsychological test data, laboratory parameters, image data and biological samples. 2. To determine the risk factors of AD and other dementias. 3. To explore the conversion rates from CN to SCI, MCI or AD and the risk factors as well as biomarkers for the progression from CN to SCI, MCI or AD. 4. To explore and validate blood, CSF, urine, imaging and other biomarkers for the early detection and progression of AD.
• Cognitive normal aging (CN) 1. 40 years and older , without cognitive impairment, MMSE≥22 2. Informed consent is signed by the participant
• Subjective cognitive impairment (SCI) Participants aged 40 and older, with absence of dementia (by DSM IV and DSM V) criteria. Normal age-, sex-, and education-adjusted performance on standardized cognitive tests, which are used to classify mild cognitive impairment (MCI) or prodromal AD. Self-experienced persistent decline in cognitive capacity in comparison with a previously normal status and unrelated to an acute event. Answering yes to both of the following questions: Do you feel like your memory or thinking is becoming worse? and Does this concern you?
• Mild cognitive impairment (MCI) 1. 40 years and older 2. Diagnosis according to 2004 Peterson's MCI criteria. 3. Clinical Dementia Rating (CDR) = 0.5. 4. Memory loss is prominent, and may also be with other cognitive domain impairment.
• 5\. Insidious onset, slow progress.
• Alzheimer's disease (AD)
‣ 50 years and older
⁃ Dementia is diagnosed according to the criteria described by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-R). The diagnosis of AD according to the National Institute of Neurologic and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS- ADRDA) or National Institute on Aging and the Alzheimer's Assocation (NIA-AA) criteria.
⁃ Subjects and their informed persons can complete relevant and follow-up examinations.
⁃ Subjects or their authorized legal guardians sign the informed consent. Vascular cognitive impairment (VCI)
• 1\. 40 years and older 2. Diagnosis according to the criteria for small vessel VCI, with the following three core elements:
• 1\) Cognitive impairment: memory decline can be highlighted 2) Vascular factors 3) Causal relationship between cognitive impairment and vascular factors 3.Cognitive impairment lasts for 3 months or more, and the CDR global score ≥0.5 point.
• 4\. All patients need to meet the following MRI criteria:
⁃ Multiple (≥3) small infarcts (3-20 mm in diameter) with or without any degree of white matter lesions (WML); or moderate to severe WML (Fazekas score ≥ 2) , with or without small infarction; or ≥ 1 small infarct in key parts of the cortex, such as: caudate nucleus, globus pallidus, thalamus et al.
⁃ No WML caused by cortical infarction, watershed infarction, hemorrhage, hydrocephalus, or other causes (such as multiple sclerosis).
⁃ No hippocampus or entorhinal cortex atrophy, Medial Temporal Lobe Atrophy (MTA)≤ 1 point.
• 5\. Subjects and their informed persons can complete relevant and follow-up examinations.
• 6\. Subjects or their authorized legal guardians sign the informed consent.