Blood-brain Barrier Permeability in Alzheimer's Disease

The main aim of the present study is to improve our understanding of the role of blood-brain barrier function in dementia of the Alzheimer's type. The investigators hypothesize that microvascular dysfunction - more specifically "cerebral perfusion and blood-brain barrier leakage" - is a determinant of cognitive decline and cortical atrophy in Alzheimer's disease.

Inclusion Criteria:

Patients with AD:

• Informed consent before participation in the study
• Received standard diagnostic procedure according to the Parelsnoer Initiative procedure
• Diagnosed with dementia of the Alzheimer's type
• Clinical dementia rating (CDR) of 1, which means a mild to moderate stage of dementia
• MMSE ≥ 20 and patients are mentally competent (in general, individuals with an MMSE ≥ 18 are considered mentally competent)

Patients with prodromal AD:

• Informed consent before participation in the study
• Received standard diagnostic procedure according to the Parelsnoer Initiative procedure
• Diagnosis of prodromal dementia according to the Dubois criteria (16)
• CDR of 0.5, which suggests a very mild stage of dementia
• Memory impairment defined as Delayed Recall on Verbal Learning Test (15 WLT) < 1.5 SD
• MMSE ≥ 20 and patients are mentally competent.
• Medial temporal lobe atrophy scale MTA ≥ 1 (17) OR abnormal levels of Aß42, t-tau or p-tau

Healthy participants:

• Informed consent before participation in the study
• No Diagnosis of dementia, prodromal dementia, or mild cognitive impairment.
• MMSE ≥ 26
• No substantial memory complaints (according to participant)
• Age, gender and education is matched to the patient groups.

Exclusion Criteria:

• Contraindications for scanning (e.g. brain surgery, cardiac pacemaker, metal implants, claustrophobia, large body tattoos)
• Contraindications for contrast agent Gadovist (renal failure) as determined by the estimated Glomular Filtration Rate eGFR < 30 mL/min.
• Major vascular disorders (e.g. stroke, heart disease)
• Psychiatric or neurological disorders: Major depression (< 12 months); history of schizophrenia; bipolar disorder; psychotic disorder NOS or treatment for a psychotic disorder (< 12 mnd); cognitive impairment due to alcohol abuse; epilepsy; Parkinson's disease; MS; brain surgery; brain trauma; electroshock therapy; kidney dialysis; Meniere's disease; and brain infections.
• Structural abnormalities of the brain
• Cognitive impairment due to alcohol/drug abuse
• Absence of reliable informant (for patient groups)