Written by Liu Hailing, Wang Qing

Editor in charge ︱ Wang Sizhen

Editor︱Yang Binwei

Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and elderly people

Quantitative electroencephalography (QEEG) is a non-invasive, high temporal resolution and objective diagnostic method that can rapidly assess transient neuronal and synaptic function and may be sensitive to early neurodegenerative changes [2]

A meta-analysis pointed out [4] that Hs-CRP, as a common peripheral inflammatory marker, can enhance the permeability of the blood-brain barrier (BBB), mediate the occurrence and progression of PD through the immune system, and predict the prognosis of PD.

On July 29, 2022, the team of Professor Wang Qing from Pearl River Hospital of Southern Medical University published a meta-analysis article on repetitive transcranial magnetic stimulation (rTMS) in the international authoritative journal eClinicalMedicine (Part of The Lancet Discovery Science) (IF: 17.

To explore the differences of QEEG indexes in PD patients with or without dementia, the authors retrospectively analyzed quantitative EEG data of PD patients in Zhujiang Hospital from 2018-7-1 to 2021-7-1

Figure 1 Flowchart

(Source: Hailing Liu, et al.

1.

In the EEG examination room, the subjects were kept quiet, eyes closed, and a comfortable sitting position after eating, and the same physician performed EEG monitoring
.

The EEG signal with a stable baseline and no obvious artifacts was selected as the analysis object, and no other filtering was added except the 50 Hz notch
.

The spectrum analysis of EEG signals was carried out on Matlab 13.
0 software, and Fourier transform was used to convert EEG time-domain signals into frequency-domain signals.
4 to 8 Hz), alpha band (8 to 13 Hz), and beta band (13 to 30 Hz)
.

The authors calculated the absolute power values ​​and the fast-slow power ratio of different frequency bands in the whole brain area, frontal area, parietal area, central area, occipital area, and temporal area: (δ + θ)/(α + β)
.

In addition, the differences in the frequency of alpha peaks in the occipital region of each group were also calculated
.

Using analysis of covariance with age as a covariate, the authors compared the whole-brain power spectra of different frequency bands in different groups of PDD, PD-ND, and HC, and found significant between-group abnormalities in the delta frequency band (P = 0.
000)
.

The fast-slow frequency band ratio, delta frequency band and alpha peak frequency in the occipital area are all characteristic indicators of EEG slowing.
Across brain regions, the slow-wave power of PDD was higher, while PD-ND did not differ compared to HC (Fig.
2)
.

Figure 2 Quantitative EEG slowing in patients with Parkinson's dementia

(Source: Hailing Liu, et al.
, eclinicalMedicine, 2022)

By comparing the topographic maps of different frequency bands between the three groups, the authors found that the delta spectral power was highest in PDD patients, especially in the frontal lobe region, and the difference was statistically significant
.

In the theta (4-8 Hz) power spectral topography, significant differences were only found in frontal and temporal regions in PDD patients
.

Comparing the peak frequencies in the occipital region of the three groups, in the occipital leads O1 and O2, the PDD peak frequency was the lowest, followed by PD-ND patients and HC (Fig.
3)
.

Figure 3 Brain topographic map and comparison of peak frequency in occipital area

(Source: Hailing Liu, et al.
, eclinicalMedicine, 2022)

2.
Serum inflammatory and metabolic markers of the difference between PDD and PD-ND

The Mann–Whitney U test univariate analysis was performed on the included serum markers between the two groups of patients with PDD and PD-ND, and it was found that HDL-C (P=0.
002), GLU (P=0.
013), Cys-C (P=0.
013) = 0.
003), Hs-CRP (P=0.
001) and ESR (P=0.
006) in PDD patients were significantly higher than those in PD-ND group, while SOD (P=0.
379), UA (P=0.
050), Chol (P=0.
379) ), LDL-C (P=0.
569), NEU% (P=0.
061), MON% (P=0.
153), LYM% (P=0.
084) had no difference between the two groups
.

The univariate analysis indicators of differences were included in logistic regression, and the results showed that HDL-C (OR=0.
186, P=0.
030) and Hs-CRP (OR=2.
856, P=0.
015) were associated with PDD
.

3.
Correlation between quantitative EEG indicators and serum inflammatory metabolic indicators

Since the frontal region delta power was most significantly different in PPD and PD-ND, the authors examined the correlation between the absolute value of the frontal region delta power and the difference in serum inflammation and metabolic indicators
.

The results showed that the absolute value of frontal delta power was negatively correlated with MMSE scores, HDL-C and SOD levels in PD patients, and positively correlated with Hs-CRP levels (Figure 4)
.

Figure 4.
Correlations between QEEG indicators and disease severity, inflammation, and metabolic indicators

(Source: Hailing Liu, et al.
, eclinicalMedicine, 2022)

4.
The significance of QEEG, inflammatory and metabolic indicators ROC curve in predicting PDD

Quantitative EEG, inflammatory, and metabolic indicators that assessed differences in ROC curves were used to identify the significance of PDD and PD-ND, and the differences were statistically significant (Fig.
5-A)
.

The ROC curve after adjusting for age, the difference was still statistically significant (Fig.
5-B)
.

The AUC of the absolute value of delta power in the frontal region (blue curve) was 0.
747, the AUC of Hs-PCR was 0.
771 (orange curve), and the AUC of HDL-C was 0.
712 (green curve)
.

The combined AUC of frontal-delta power absolute, Hs-PCR and HDL-C (red curve) was 0.
801
.

Figure 5.
ROC curve evaluation of quantitative EEG, inflammation, and metabolic markers for the identification of PDD and PD-ND

((Source: Hailing Liu, et al.
, eclinicalMedicine, 2022)

Conclusions and Discussions, (Future) Inspirations and Prospects In conclusion, in Parkinson's disease (PD) patients, the authors found that quantitative electroencephalogram (QEEG) indicators were correlated with serum inflammatory and metabolic indicators; The index is related to the severity of Parkinson's dementia (PDD); the combination of QEEG index with HDL-C and Hs-CRP may be one of the auxiliary and effective means to assess PDD
.

The authors' current findings suggest that peripheral inflammatory, metabolic markers may be involved in the pathogenesis of cognitive impairment and EEG slowing in PDD
.

In future clinical trials, the authors will further investigate the association of QEEG with neuroinflammation and other metabolic markers in patients with PDD
.

Original link: https://doi.
org/10.
1016/j.
eclinm.
2022.
101615

Corresponding author: Wang Qing

(Photo courtesy of: Wang Qing Laboratory, Pearl River Hospital, Southern Medical University)

About the author (swipe up and down to read) 

Director of Neurology Department, Zhujiang Hospital, Southern Medical University, Associate Editor of Frontiers in Aging Neuroscience (5.
7), Guest Editor of Journal of Clinical Medicine (4.
96), Journal of Aging and Disease (9.
97), Experimental Neurology (5.
6), Frontiers in Cellular Neuroscience (6.
1) The editorial board has undertaken 973, major research and development plan sub-projects, and published more than 80 SCI papers in more than 40 projects including the National Natural Science Foundation of China (5 aspects).
IF:17), Brain (15.
3), Progress in Neurobiology (10.
8), EBioMedicine (11.
2), Brief Bioinform (13.
99), Move Disord (10.
8), more than 40 articles > 5 points, he cited 2800+ times, H-index 28
.

Selected past articles

[1] PNAS︱Li Gang's research group draws the developmental pattern and regionalization map of infant cerebral cortex surface area

【2】Front Mol Neurosci︱Chen Jun's research group revealed that secondary nerve injury and neuroinflammation in the spinal dorsal horn mediate thalamic hemorrhagic post-stroke pain

【3】Aging Cell︱Xiao Jianhui's team reported a potential anti-aging drug: Ganoderma lucidum D activates the CaM/CaMKII/NRF2 signaling axis to delay stem cell aging

【4】Mol Psychiatry︱Zheng Wei/Liao Fang team work together to reveal early events of white matter lesions in vascular cognitive impairment and dementia

[5] Cell Rep | Xing Dajun's research group published a paper revealing the differences between the primary visual cortex of macaques and convolutional neural networks in integrating visuospatial information

【6】Neuron｜Hu Yang's group revealed a large number of genes that promote optic nerve regeneration and their significant neuroprotective effects in glaucoma mice

【7】Cereb Cortex︱Zhang Yuxuan's research group reveals the neurophysiological evidence of task modulation in speech processing

[8] Trends Cogn Sci︱Qiu Jiang's team writes opinion articles on creative problem solving in knowledge-rich fields

【9】Front Aging Neurosci︱Hongmei Yu’s team constructed a hierarchical multi-classification diagnosis framework for AD based on imaging features and clinical information

【10】J Neurosci︱Jin Mingyue / Guangchang Shinji's team revealed that α-Syn and tau play an important synergistic physiological function during brain development

Recommended high-quality scientific research training courses

[1] Symposium on Single-Cell Sequencing and Spatial Transcriptomics Data Analysis (August 27-28, Tencent Online Conference)

【2】Training course︱R language clinical prediction biomedical statistics special training

[3] Workshop on Metagenomics and Metabolomics R Language Analysis and Visualization (Tencent Conference on August 27)

Forum/Seminar Preview

【1】Forum Preview︱Brain·Machine Intelligence Fusion——Let the brain connect to the future, the brain science theme forum is the first time!

Welcome to "Logical Neuroscience" [1] Talent Recruitment︱"Logical Neuroscience" is looking for article interpretation/writing positions (part-time online, online office)

References (swipe up and down to read) 

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End of this article