PhD Scientific Days 2023

Neurosciences - Posters G

The Role of Sleep Structure Analysis in the Recognition of Alzheimer's Spectrum Disease

Text of the abstract

Introduction
The prevalence of neurocognitive disorders is 4-5% in Hungary representing the leading cause of death by the elderly. Alzheimer’s disease (AD) effective treatment is absent due to difficulties in early differential diagnosis. Sleep-wake disturbances are common in AD, even at early stages.

Aims
Our aim is to study the potential role of micro- and macrostructul sleep changes as early differencial
diagnostic tools.

Method
We involved 30 individuals with AD, and 30 controls. Sleep structure was examined with 24-
hour Holter electroencephalograph (EEG), followed by visual evaluation. For microstructural
analysis K-complex detection was used. Brain magnetic resonance imaging (MRI) and
neuropsychological tests were also performed. 32 patients with mild cognitive impairment
(MCI) and 46 healthy controls were also involved. Spearmann correlation and ANCOVA
analyses were used for statistical evaluation.

Results
A rearrangement of sleep stages was observed in AD. Significant decrease was found both in
K-complex densities avaraged for total sleep (F: 0.216; p<0.001) and for S2 sleep (F: 0.386;
p<0.001). Based on the MRI examination, significant positive correlation was found between
right caudal anterior gyrus cingulate thickness and both type of K-complex densities (total
sleep: r=0.458; p=0.042; S2 sleep: r=0.472; p=0.036). In the MCI patient group, there was a
significant reduction in right caudal anterior gyrus cingulate thickness (2.53±0.2 mm vs.
2.42±0.3 mm; p=0.004; Cohen’s d: 0.353), showing the potential of K-complex analysis in
early recognition.

Conclusion
Macro- and microstructural sleep changes were significantly observed in AD which may be
good markers of neurocognitive status. K-complex density is significantly decreased in AD,
which raises the possibility that it may have a great impact in the preclinical detection of AD.

Funding
National Brain Research Program II (2017-1.2.1-NKP-2017-00002)

e-mail: kegyes.brassai.anna@gmail.com
University and Doctoral School: Semmelweis University, MD-PhD Excellence Program
Supervisors: András Horváth M.D., P.h.D., Prof. Dr Anita Kamondi, MD, CSc, DSc