[Diagnosis without therapy: early diagnosis of Alzheimer's disease in the stage of mild cognitive impairment].

Alzheimer's disease (AD) is a histopathologically defined progressive neurodegenerative disorder. Its clinical manifestation can be subdivided into the stage of mild cognitive impairment (MCI) and the stage of dementia. According to ICD-10 the diagnosis of AD can only be made in the stage of dementia. The indication for anti-dementia drugs is restricted to the stage of dementia in AD, too. Diagnostic tools to detect AD have improved considerably in recent years. They include the MRI findings of atrophy of the medial temporal lobe, cerebrospinal fluid (CSF) biomarkers β-amyloid and τ, the visualisation of metabolic deficits on positron emission tomography (PET) using [(18)F]-fluoro-2-deoxy-D-glucose (FDG) and the emerging possibility to demonstrate amyloid deposits in vivo using PET ligands. The application of these methods allows the diagnosis of AD to be established already in the stage of MCI. While diagnostic methods improve and enable us to make the diagnosis of AD very early, there is no such progress in the development of treatment options. Early diagnosis of AD appears to have benefits and drawbacks. It is most important to include the patient in the decision on early diagnosis and to make clear that there is a lack of therapeutic options if the diagnosis is positive.