Diagnostic and prognostic value of EEG in prodromal dementia with Lewy bodies

Neurology. 2020 Aug 11;95(6):e662-e670. doi: 10.1212/WNL.0000000000009977. Epub 2020 Jul 7.


Objective: Early biomarkers for dementia with Lewy bodies (DLB) are lacking. To determine whether EEG differentiates the prodromal phase of DLB from other causes of mild cognitive impairment (MCI) and whether EEG is predictive for time to conversion from MCI to DLB, we compared EEGs and clinical follow-up of patients with MCI due to DLB with those of patients with MCI due to Alzheimer disease (MCI-AD).

Methods: We compared 37 patients with MCI who developed DLB during follow-up or had an abnormal 123I-PF-CIT SPECT scan (MCI-DLB) with 67 age-matched patients with MCI-AD. EEGs were assessed visually with a score of increasing abnormality (range 1-5). We performed fast Fourier transform to analyze the power spectrum. With survival analyses, EEG characteristics were related to time to progression to dementia.

Results: The visual EEG score was higher in MCI-DLB (score >2 in 60%) compared to MCI-AD (score >2 in 8%, p < 0.001). We found frontal intermittent delta activity in 22% of MCI-DLB, not in MCI-AD. Patients with MCI-DLB had a lower peak frequency (7.5 [6.0-9.9] Hz vs 8.8 [6.8-10.2] in MCI-AD, p < 0.001) and more slow-wave activity. Several individual EEG measures showed good performance to discriminate MCI-DLB from MCI-AD (areas under the curve up to 0.94). In MCI-DLB, high visual EEG score, diffuse abnormalities, and low α2 power were related to time to progression to dementia (hazard ratios 4.1, 9.9, 5.1, respectively).

Conclusions: Profound EEG abnormalities are already present in the prodromal stage of DLB and have diagnostic and prognostic value.

Classification of evidence: This study provides Class III evidence that EEG abnormalities are more common in MCI-DLB than MCI-AD.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / diagnostic imaging
  • Alzheimer Disease / physiopathology
  • Amyloid beta-Peptides / cerebrospinal fluid
  • Cognitive Dysfunction / cerebrospinal fluid
  • Cognitive Dysfunction / diagnostic imaging
  • Cognitive Dysfunction / physiopathology
  • Diagnosis, Differential
  • Disease Progression
  • Early Diagnosis
  • Electroencephalography*
  • Female
  • Follow-Up Studies
  • Fourier Analysis
  • Humans
  • Iodine Radioisotopes
  • Lewy Body Disease / cerebrospinal fluid
  • Lewy Body Disease / diagnosis*
  • Lewy Body Disease / diagnostic imaging
  • Lewy Body Disease / physiopathology
  • Male
  • Middle Aged
  • Netherlands
  • Peptide Fragments / cerebrospinal fluid
  • Prospective Studies
  • Radiopharmaceuticals
  • Symptom Assessment
  • Time Factors
  • Tomography, Emission-Computed, Single-Photon
  • Tropanes
  • tau Proteins / cerebrospinal fluid


  • Amyloid beta-Peptides
  • Iodine Radioisotopes
  • MAPT protein, human
  • Peptide Fragments
  • Radiopharmaceuticals
  • Tropanes
  • amyloid beta-protein (1-42)
  • tau Proteins
  • 2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane
  • Iodine-123