Normalized Theta but Increased Gamma Activity after Acetylcholinesterase Inhibitor Treatment in Alzheimer's Disease: Preliminary qEEG Study


Fide E., Yerlikaya D., Oz D., Oztura I., YENER G.

CLINICAL EEG AND NEUROSCIENCE, no.3, pp.305-315, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2023
  • Doi Number: 10.1177/15500594221120723
  • Journal Name: CLINICAL EEG AND NEUROSCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Biotechnology Research Abstracts, EMBASE, MEDLINE
  • Page Numbers: pp.305-315
  • Keywords: acetylcholinesterase inhibitors (AChE-I), Alzheimer's disease (AD), EEG power and coherence, gamma band, theta band, alpha band, QUANTITATIVE EEG, CHOLINESTERASE INHIBITOR, CHOLINERGIC HYPOTHESIS, FREQUENCY OSCILLATIONS, EPILEPTIFORM ACTIVITY, SPECTRAL-ANALYSIS, NUCLEUS BASALIS, DONEPEZIL, MEMORY, RIVASTIGMINE
  • Dokuz Eylül University Affiliated: Yes

Abstract

Acetylcholinesterase inhibitors (AChE-I) are the core treatment of mild to severe Alzheimer's disease (AD). However, the efficacy of AChE-I treatment on electroencephalography (EEG) and cognition remains unclear. We aimed to investigate the EEG power and coherence changes, in addition to neuropsychological performance, following a one-year treatment. Nine de-novo AD patients and demographically-matched healthy controls (HC) were included. After baseline assessments, all AD participants started cholinergic therapy. We found that baseline and follow-up gamma power analyzes were similar between groups. Yet, within the AD group after AChE-I intake, individuals with AD displayed higher gamma power compared to their baselines (P < .039). Also, baseline gamma coherence analysis showed lower values in the AD than in HC (P < .048), while these differences disappeared with increased gamma values of AD patients at the follow-up. Within the AD group after AChE-I intake, individuals with AD displayed higher theta and alpha coherence compared to their baselines (all, P < .039). These increased results within the AD group may result from a subclinical epileptiform activity. Even though AChE-I is associated with lower mortality, our results showed a significant effect on EEG power yet can increase the subclinical epileptiform activity. It is essential to be conscious of the seizure risk that treatment may cause.