Dementia with Lewy body disease (DLB) is the second leading cause of degenerative cognitive disorder after Alzheimer's disease (AD). Its variable clinical expression makes diagnosis difficult. To date, there is no validated DLB diagnostic biomarker, despite several biomarkers in development (EEG, MRI, biology).

Studies have shown that an improvement in diagnostic performance could be obtained by combining different modalities biomarkers using machine learning.

The aim of this research is to identify the best combination of multimodal biomarkers for the diagnosis of DLB (EEG, MRI, biology, cognitive scores), using a machine learning approach applied to a clinical cohort.

Study population: Observational prospective cohort study including over 24 months at the GHU AP-HP. Nord Lariboisière, Cognitive Neurology Center : 50 probable DLB patients, 50 AD patients, and 30 control subjects with subjective cognitive impairment but without any element in favor of neurodegenerative disorders. Total clinical dataset n= 130.

Act :

• 32-electrode EEG (resting state, passive auditory and active visual task).
• 4 dry electrode EEG cap simultaneously with the 32-electrode EEG

Expected results: Improved DLB diagnosis performance using a combination of multimodal biomarkers (EEG, cognitive scores, plasma, brain MRI).

Inclusion Criteria for DLB ant AD patients:

• Neuropsychological assessment possible (good level in French language, absence of visual/auditory deficit limiting the cognitive assessment)
• Dementia with Lewy bodies according to the revised criteria of Mc Keith 2017 or probable AD defined according to McKhann 2011 criteria including CSF biomarkers (an abnormal level of beta-amyloid 1-42 protein [Ab42] or a pathological Ab42/Ab40 ratio and an abnormal level of phosphorylated tau [p-tau])

Inclusion Criteria for control patients:

• Neuropsychological assessment possible (good level in French language, absence of visual/auditory deficit limiting the cognitive assessment)
• MMSE (Mini-mental State Examination) greater than or equal to 28, normal MemScreen test results, normal brain MRI and normal neurological examination

Exclusion Criteria (for all) :

• Contraindication to MRI
• Other neurological or psychiatric or toxic/iatrogenic disorders that may account for the cognitive impairment or for EEG abnormalities
• Any unstable medical pathology and/or that may account for the cognitive impairment

Observational prospective cohort study included at the GHU AP-HP. Nord Lariboisière, Cognitive Neurology Center : 50 probable DLB patients, 50 AD patients, and 30 control subjects with subjective cognitive impairment but without any element in favor of neurodegenerative disorders