Cognitive load associates prolonged P300 latency during target stimulus processing in individuals with mild cognitive impairment

Abstract Alterations in P300 amplitude and latency, as well as neuropsychological tests, are informative to detect early signs of the affected high cognitive processing in Mild Cognitive Impairment (MCI). In the present study, we examined P300 latency and amplitude elicited by visual oddball paradigm in 20 participants with MCI and age, education, and sex-matched healthy controls from frontal, central, and parietal midline electrodes. We performed a mixed-design ANOVA to compare P300 amplitude and latency between groups during target and non-target stimulus presentation. We also assessed the correlation between our electrophysiology findings and neuropsychological tests. Our results indicated that in healthy individuals P300 is elicited earlier in target stimulus processing compared to non-target stimulus processing. On the contrary, in the MCI group, P300 latency was increased during target processing compared to non-target stimulus processing. Moreover, P300 latency in target processing is prolonged in the MCI group compared to controls. Also, our correlation results showed a significant correlation between P300 peak latency and amplitude, and attention required cognitive tasks. In conclusion, our results provide evidence that high-order cognitive processes that are involved in stimulus processing slows down in individuals with MCI due to the high working memory demand for neural processing

Neurodegeneration and Epileptic Seizure: Earlier Than We Think

Objective:The purpose of this study is to compare demographical and cognitive features of patients who have neurodegenerative diseases with or without seizures.Methods:This descriptive retrospective study included a total of 16 348 participants, 479 with seizures and 15 869 without seizures. Independent samples t-test and chi-square tests were used to compare age, education, Mini Mental State Examination, and gender of groups.Results:There was a significant difference between patients with seizures and without seizures in age [t(3764) = 2.815, P = .005]. It is found that patients with seizures (M = 67.51, standard deviation = 9.69) were significantly younger than patients without seizures (M = 70.37, standard deviation = 9.51).Conclusion:In all neurodegenerative diseases, especially Alzheimer’s disease, at an early age and regardless of cognitive status, diagnosis of seizures at the first admission and subsequent follow-ups is of great importance in terms of the patient’s quality of life, prognosis of the disease, and treatment options

Reduced power and phase-locking values were accompanied by thalamus, putamen, and hippocampus atrophy in Parkinson's disease with mild cognitive impairment: An event-related oscillation study

Parkinson's disease (PD) is a multifaceted neurodegenerative disorder accompanied by mild cognitive impairment (MCI) as a crucial nonmotor manifestation. Event-related oscillations (EROs) are suggested to reflect cognitive status associated with subcortical structures in neurodegenerative conditions. In this study, 36 individuals with PD-MCI and 32 PD-CN were compared with 60 healthy control (HC) participants using visual EROs by measures of event-related spectral perturbation and inter-trial coherence, along with subcortical gray matter volumes based on the FIRST algorithm. Cross-correlations among electrophysiological, neuropsychological, and structural parameters were investigated exploratively. Both PD-MCI and PD-CN patients had diminished delta and alpha phase-locking than HC, however, electrophysiological abnormalities were more pronounced in PD-MCI over frontal, central, parietal, and temporal locations in almost all frequency bands, accompanied by bilateral thalamus, hippocampus, and right putamen atrophy. PD-CN had lower hippocampal volumes than HC, without exhibiting any subcortical differences from PD-MCI. Lastly, EROs showed low-to-high correlations with structural and neuropsychological measures. These findings may highlight the complex interplay between electrophysiological, neuropsychological, and structural parameters in detected abnormalities of PD-CN and PD-MCI.Dokuz Eylül Üniversites