Prefrontal and Occipital Network Excitability Differences in Dementia with Lewy Bodies and Alzheimer's Disease

Summary

Distinguishing dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) remains a clinical challenge. This study used TMS-evoked potentials (TEPs), a non-invasive measure of neurophysiological changes, to compare network excitability in the two conditions.

Study design

• Participants: 39 in total, 12 with DLB, 10 with AD and 17 age-matched healthy controls.
• TEPs were recorded after stimulation of the dorsolateral prefrontal cortex (DLPFC), primary motor cortex (M1) and primary visual cortex (V1).

Key findings

• Late global mean field potential (130–250 ms) after V1 stimulation was higher in DLB than in AD and in healthy controls (p = .001 for both comparisons).
• The P60 amplitude after DLPFC stimulation differed between DLB and AD (p = .0013) and between DLB and controls (p = .0032).
• DLPFC N45 amplitude correlated with motor symptom severity on the UPDRS-III (r = 0.9, p = .0002).
• In AD, a relatively higher left-over-right DLPFC P30 amplitude correlated with poorer MoCA scores (r = −0.84, p = .002).

Authors' conclusions

The authors propose the DLPFC as a target for assessing motor symptom severity in DLB and cognitive impairment in AD, and suggest that DLPFC and V1 network characteristics offer a promising non-invasive method to distinguish DLB from AD and to monitor disease.

Read the full article

Bregman N, Zifman N, Fogel H, Abulher E, Maidan I, Shiner T. Prefrontal and Occipital Network Excitability Differences in Dementia with Lewy Bodies and Alzheimer's Disease. Clinical EEG and Neuroscience. 2026. doi:10.1177/15500594261452759

Summary prepared by QuantalX from the published abstract. All results are as reported by the authors. The full text is available from the publisher.