Overview

This is a multi-center study that has three cohorts: 1) cognitive normal cohort (CN), 2) Alzheimer's disease cohort (AD) and 3) vascular cognitive impairment cohort (VCI). The goal of this study is to understand the risk factors of AD and VCI and to identify high risk patients for early intervention. It will collect demographic information, family history, medical history, neuropsychological tests, imaging studies and biological samples through standard and uniform procedures.

Eligibility

1. The inclusion and exclusion criteria of AD group.

             1.1 The AD group inclusion criteria: 1.1.1 Aged 40-100 years old (≥ 40 years old, ≤
             100 years old). 1.1.2 Diagnosed with AD according to Alzheimer disease diagnostic
             criteria following NINCDS-ADRDA1984 or NIA-AA 2011 guideline.
             1.1.3 Had adequate hearing, vision and comprehension and verbal expression to complete
             the cognitive assessments.
             1.1.4 Had at least 3 years of education. 1.1.5 Signed informed consent.
             1.2 The AD group exclusion criteria: 1.2.1 Sequelae after previous history of severe
             central nervous system infection, multiple sclerosis, autoimmune encephalitis,
             Hashimoto's encephalopathy, etc.
             1.2.2 Previous history of instable epilepsy. 1.2.3 Systemic diseases affect the
             central nervous system (CNS), such as abnormal liver and kidney functions.
             1.2.4 History of hereditary diseases that affect cognitive function (such as
             Huntington's disease, Down's syndrome, CADASIL, adrenal leukodystrophy, mitochondrial
             encephalopathy, etc.).
             1.2.5 Infection and immune-related diseases affecting the central nervous system
             (systemic lupus erythematosus, undertreated HIV infection or a history of CNS syphilis
             infection, etc.).
             1.2.6 Metabolic and endocrine disorders (requiring new treatment or adjustment of
             current treatment for thyroid dysfunction, folate or vitamin B12 deficiency).
             1.2.7 Had contraindications for MRI (e.g., pacemakers, stents, claustrophobia.) or did
             not cooperate with PET scans.
          2. The inclusion and exclusion criteria of post-stroke cognitive observation group.
             2.1 The inclusion criteria of post-stroke cognitive observation group: 2.1.1 Aged
             40-100-years old (≥ 40 years old, ≤ 100 years old). 2.1.2 Cerebral infarction is
             diagnosed according to World Health Organization diagnostic criteria13 and was the
             first symptomatic onset.
             2.1.3 The time from onset to enrollment was less than 7 days. 2.1.4 Had adequate
             hearing, vision and comprehension and verbal expression to complete the cognitive
             assessments.
             2.1.5 Had at least 3 years of education. 2.1.6 Signed informed consent.
             2.2 The exclusion criteria of post-stroke cognitive observation group: 2.2.1 Prior to
             the onset of acute infarction had no conditions known to affect cognitive function,
             such as vascular dementia, dementia with Lewy body dementia, frontotemporal dementia,
             Parkinson's disease dementia, epilepsy, stroke, hydrocephalus, multiple sclerosis,
             traumatic brain injuries, genetic disorders affecting cognition, alcoholism,
             uncontrolled depression or other psychiatric disorders and Alzheimer's disease and
             IQCODE>3.5.
             2.2.2 Sequelae after previous history of severe central nervous system infection,
             multiple sclerosis, autoimmune encephalitis, Hashimoto's encephalopathy, etc.
             2.2.3 Previous history of instable epilepsy. 2.2.4 Systemic diseases affect the CNS,
             for abnormal liver and kidney functions.
             2.2.5 History of hereditary diseases that affect cognitive function (such as
             Huntington's disease, down syndrome, CADASIL, adrenal leukodystrophy, mitochondrial
             encephalopathy, etc.).
             2.2.6 Infection and immune-related diseases affecting the central nervous system
             (systemic lupus erythematosus, undertreated HIV infection or a history of CNS syphilis
             infection, etc.).
             2.2.7 Metabolic and endocrine disorders (requiring new treatment or adjustment of
             current treatment for thyroid dysfunction, folate or vitamin B12 deficiency).
             2.2.8 Reject or had contraindications for MRI (e.g., pacemakers, stents,
             claustrophobia.).
          3. The inclusion and exclusion criteria of normal cognitive group.
        3.1 The inclusion criteria of normal cognitive group: 3.1.1 Aged 40-100 years old (≥ 40
        years old, ≤ 100 years old). 3.1.2 The patients are cognitively normal and able to live and
        work independently.
        3.1.3 Had adequate hearing, vision and comprehension and verbal expression to complete the
        cognitive assessments.
        3.1.4 Had at least 3 years of education. 3.1.5 Signed informed consent.
        3.2 The exclusion criteria of normal cognitive group: 3.2.1 The patients had no conditions
        known to affect cognitive function, such as vascular dementia, dementia with Lewy body
        dementia, frontotemporal dementia, Parkinson's disease, epilepsy, stroke, hydrocephalus,
        multiple sclerosis, traumatic brain injuries, genetic disorders affecting cognition,
        alcoholism, uncontrolled depression or other psychiatric disorders, Parkinson's disease,
        epilepsy or Alzheimer's disease.
        3.2.2 Sequelae after previous history of severe central nervous system infection, multiple
        sclerosis, autoimmune encephalitis, Hashimoto's encephalopathy, etc.
        3.2.3 Previous history of instable epilepsy. 3.2.4 Systemic diseases affect the CNS, for
        abnormal liver and kidney functions.
        3.2.5 History of hereditary diseases that affect cognitive function (such as Huntington's
        disease, down syndrome, CADASIL, adrenal leukodystrophy, mitochondrial encephalopathy,
        etc.).
        3.2.6 Infection and immune-related diseases affecting the central nervous system (systemic
        lupus erythematosus, undertreated HIV infection or a history of CNS syphilis infection,
        etc.).
        3.2.7 Metabolic and endocrine disorders (requiring new treatment or adjustment of current
        treatment for thyroid dysfunction, folate or vitamin B12 deficiency).
        3.2.8 Reject or had contraindications for MRI (e.g., pacemakers, stents, claustrophobia.).