Deficits in saccadic eye movements differ between subtypes of patients with mild cognitive impairment

Introduction: Mild cognitive impairment (MCI) is known to be heterogeneous in its cognitive features and course of progression. Whilst memory impairment is characteristic of amnestic MCI (aMCI), cognitive deficits other than memory can occur in both aMCI and non-amnestic MCI (naMCI) and accurate assessment of the subtypes of MCI is difficult for clinicians without the application of extensive neuropsychological testing. In this study, we examine metrics derived from recording of reflexive and voluntary saccadic eye movements as a potential alternative method for discriminating between subtypes and assessing cognitive functions in MCI. Method: A total of 29 MCI patients and 29 age- and education-matched healthy controls (HCs) participated in the cross-sectional study. We recorded horizontal and vertical pro-saccades and anti-saccade responses. All the participants also completed a comprehensive neuropsychological tests battery. Results: Significant differences in saccadic eye movement were found between the subtypes of MCI and HCs. Patients with aMCI had a higher percentage of short latency “express” saccades than HCs. We found strong associations between saccadic reaction times and cognitive domains, including executive functions and attention. The mini-mental state examination (MMSE) was also found to correlate with uncorrected errors in the anti-saccade task. Conclusions: The increased proportion of saccades in the express latency range in aMCI may be indicative of problems with cognitive inhibitory control in these patients. A focus on this and other saccade metrics in the preclinical and prodromal stages of dementia may help to predict the clinical progression of the disease and direct interventions for the management of MCI. The clinical significance of saccadic eye movement impairments in MCI is not yet fully understood and should be investigated in further studies using larger samples

Investigation of the Effect of Antiseizure Medications on Cognition in Patients With Epilepsy

Background. The effect of antiseizure medications (ASMs) on cognition varies depending on the type of ASM. We aimed to investigate the effects of ASMs on patients with epilepsy based on the conflicting findings in the literature. Methods. Patients diagnosed with epilepsy who were taking ASMs were included. All patients underwent a neuropsychiatric assessment, Beck Depression and Anxiety Inventories, Positive and Negative Syndrome Scale, and general psychopathological tests. The patients were divided into polytherapy and monotherapy groups. Subgroups were categorized according to the type of ASMs, dosage, and duration of monotherapy. Results. Ninety-seven patients were included in this study. The polytherapy group showed a significant decrease in attention, total learning, and interpretation of proverbs compared to the monotherapy group. In the monotherapy group, carbamazepine use had a moderate positive correlation with working memory (r =.669; P =.034), and a strong negative correlation with maintaining attention (r = −.740; P =.014). The duration of levetiracetam monotherapy was negatively correlated with verbal memory (immediate recall r = −.436, P =.038; free recall r =.426, P =.043) and negatively weakly correlated with naming performance (r = −.488, P =.025). Conclusion. The study showed polytherapy may affect verbal and working memory. Carbamazepine may affect working memory and the maintenance of attention in a dose-dependent manner. Levetiracetam may cause impairments in verbal memory and naming, depending on the duration of usage

Saccadic Eye Movements in Patients with Mild Cognitive Impairment: A Longitudinal Study

Saccadic eye movements are one of the sensitive and noninvasive methods to help monitor the cognitive course of mild cognitive impairment (MCI). The study aimed to evaluate both pro and anti-saccade longitudinally and the relationship between cognitive functions and eye movements in MCI subgroups and healthy controls (HCs) at a two-year follow-up. This study revealed that the anti-saccade anticipatory responses decreased in amnestic MCI (aMCI). Correct vertical pro-saccades increased in non-amnestic MCI (naMCI), while the express saccades decreased. Our study demonstrated that longer than two years of follow-up is necessary to monitor the course of MCI. Findings of the relationships between longitudinal changes of saccades and cognitive measurements demonstrated the usability of eye movements in evaluating the process of MCI

Visual search for real‐world scenes in patients with Alzheimer's disease and amnestic mild cognitive impairment

Abstract Background Visual attention‐related processes that underlie visual search behavior are impaired in both the early stages of Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI), which is considered a risk factor for AD. Although traditional computer‐based array tasks have been used to investigate visual search, information on the visual search patterns of AD and MCI patients in real‐world environments is limited. Aim The objective of this study was to evaluate the differences in visual search behaviors among individuals with AD, aMCI, and healthy controls (HCs) in real‐world scenes. Materials and Methods A total of 92 participants were enrolled, including 28 with AD, 32 with aMCI, and 32 HCs. During the visual search task, participants were instructed to look at a single target object amid distractors, and their eye movements were recorded. Results The results indicate that patients with AD made more fixations on distractors and fewer fixations on the target, compared to patients with aMCI and HC groups. Additionally, AD patients had longer fixation durations on distractors and spent less time looking at the target than both patients with aMCI and HCs. Discussion These findings suggest that visual search behavior is impaired in patients with AD and can be distinguished from aMCI and healthy individuals. For future studies, it is important to longitudinally monitor visual search behavior in the progression from aMCI to AD. Conclusion Our study holds significance in elucidating the interplay between impairments in attention, visual processes, and other underlying cognitive processes, which contribute to the functional decline observed in individuals with AD and aMCI