Multi center study of six Memory Clinics in four Nordic countries in validating a prognostic diagnostic investigation of qEEG in Mild Cognitive Impairment (MCI). The study is in two parts, the first one is a follow up of a previous study conducted in 2011-2013 and the second half is new recruitment with two years follow up. End points are diagnosis of a dementing disorder, primarily dementia of Alzheimer´s type.

The Nordic Network in Dementia Diagnostics (NIDD) conducted a study in 2011-2013 on qEEG using a method of Statistical Pattern Recognition (SPR) in six academic Memory Clinics in four Nordic countries. In the current study, those from the former study diagnosed either with Mild Cognitive Impairment (MCI; n= 120) or with Subjective Cognitive Impairment (SCI; n=60) are contacted again and evaluated for cognitive impairment. The EEG registered at entry in the former study is considered in relation to their current diagnosis (SCI,MCI or dementia) and thereby, the prognostic value of the method is evaluated.

In the second part of the study (n=120), new patients evaluated in the Memory Clinics and diagnosed with MCI (not SCI) are invited to participate for a two year follow up.

In the diagnostic work-up, simple screening tests and information from a close relative form the basis of the cognitive status (SCI;MCI, Dementia). In evaluating the cause of cognitive impairment, detailed neuropsychological testing is performed as well as MRI of the brain and CSF for Alzheimer´s markers. qEEG with SPR analysis is registered but the clinician is blinded to its outcome.

The end point in both parts of the study is a diagnosis of a dementing disorder.

Inclusion Criteria:

Group 1: Individuals diagnosed with either SCI or MCI during 2011-2013 Group 2: Individuals diagnosed with MCI at entry of the study

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Exclusion Criteria:

• Age <50 years or >85 years
• Medically or psychologically unstable
• Living outside the capital region

Individuals referred for diagnostic evaluation to an academic Memory Clinic (MC) in either of the six participating centers.

Group 1: Individuals diagnosed with either SCI or MCI in a study by the same centers in 2011-2013 Group 2: Individuals referred to the same academic MC, diagnosed with the cognitive status of MCI at the first visit. They are followed up for 2 years for evaluation of their cognitive status and if diagnosed with dementia, their disorder is registered.