Quantitative electroencephalography in the diagnosis of dementia with Lewy bodies

The spectral analysis of the resting-state eyes-closed electroencephalographic (rsEEG) activity typically shows abnormal delta (< 4 Hz), theta (4-7 Hz), and alpha (8-12 Hz) power in older patients with cognitive deficits due to progressive neurodegenerative diseases. Interestingly, abnormally prominent posterior rsEEG power < 8 Hz with periodic fluctuations in the pre-alpha/theta range has been considered a supportive biomarker for diagnosing patients with prodromal or manifest dementia due to Lewy bodies (DLB) in international guidelines. Here, a panel of experts shortly reviews the concepts of thalamocortical dysrhythmia as a possible neurophysiological oscillatory mechanism generating those rsEEG abnormalities in DLB patients. It also recommends how to record and quantitatively analyze rsEEG activity in prodromal and manifesting DLB patients for the application of that cost-effective and largely available diagnostic procedure in clinical practice.