Abnormalities of Cortical Neural Synchronization Mechanisms in Subjects with Mild Cognitive Impairment due to Alzheimer’s and Parkinson’s Diseases: An EEG Study

Abstract

Abstract. The aim of this retrospective and exploratory study was that the cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms might reveal different abnormalities in cortical neural synchronization in groups of patients with mild cognitive impairment due to Alzheimer's disease (ADMCI) and Parkinson's disease (PDMCI) as compared to healthy subjects. Clinical and rsEEG data of 75 ADMCI, 75 PDMCI, and 75 cognitively normal elderly (Nold) subjects were available in an international archive. Age, gender, and education were carefully matched in the three groups. The Mini-Mental State Evaluation (MMSE) was matched between the ADMCI and PDMCI groups. Individual alpha frequency peak (IAF) was used to determine the delta, theta, alpha1, alpha2, and alpha3 frequency band ranges. Fixed beta1, beta2, and gamma bands were also considered. eLORETA estimated the rsEEG cortical sources. Receiver operating characteristic curve (ROC) classified these sources across individuals. Results showed that compared to the Nold group, the posterior alpha2 and alpha3 source activities were more abnormal in the ADMCI than the PDMCI group, while the parietal delta source activities were more abnormal in the PDMCI than the ADMCI group. The parietal delta and alpha sources correlated with MMSE score and correctly classified the Nold and diseased individuals (area under the ROC = 0.77-0.79). In conclusion, the PDMCI and ADMCI patients showed different features of cortical neural synchronization at delta and alpha frequencies underpinning brain arousal and vigilance in the quiet wakefulness. Future prospective cross-validation studies will have to test these rsEEG markers for clinical applications and drug discovery.

Cognitive Impairment in Parkinson’s Disease Is Reflected with Gradual Decrease of EEG Delta Responses during Auditory Discrimination

“…In the spontaneous EEG analysis, the researchers indicated slowing of delta and theta activity in PD patients in comparison to healthy controls ( Neufeld et al, 1988 , 1994 ; Bonanni et al, 2008 ; Serizawa et al, 2008 ; Pugnetti et al, 2010 ). Increased delta and theta and reduced alpha and beta activity were also reported for PD patients with dementia ( Caviness et al, 2007b ; Babiloni et al, 2017 ). Event related potentials of PD patients were also investigated upon application of several paradigms.…”

Revolution of Alzheimer Precision Neurology. Passageway of Systems Biology and Neurophysiology

“…Concerning cortical source space, resting state delta and alpha sources classified Nold subjects versus ADD/DLB/PDD patients and ADD versus PDD patients with 0.85–0.90 [326]. Milder classification effects were observed in PDD and ADD individuals with MCI [377]. …”

A comparative clinical and encephalographic study on manifestation of the choline and dopamine deficiency syndromes in consciousness recovery after severe traumatic brain injury

“…It is noteworthy how our data on beta activity, as an EEG marker for the post-traumatic DD syndrome, are consistent with other research on dopaminergic system dysfunction. This beta activity, indeed, was described as an early predictor of Parkinson's disease (PD) [21]. The increased power of EEG beta-components compared to the norm was described as characteristic of PD, with moderately increased power in the theta frequency range [22].…”