Neuropsychological profile of adult patients with nonsymptomatic occipital lobe epilepsies

Repetitive transcranial magnetic stimulation regulates effective connectivity patterns of brain networks in the spectrum of preclinical Alzheimer's disease

Objectives

Subjective cognitive decline (SCD) and amnestic mild cognitive impairment (aMCI) are considered as the spectrum of preclinical Alzheimer's disease (AD), with abnormal brain network connectivity as the main neuroimaging feature. Repetitive transcranial magnetic stimulation (rTMS) has been proven to be an effective non-invasive technique for addressing neuropsychiatric disorders. This study aims to explore the potential of targeted rTMS to regulate effective connectivity within the default mode network (DMN) and the executive control network (CEN), thereby improving cognitive function.

Methods

This study included 86 healthy controls (HCs), 72 SCDs, and 86 aMCIs. Among them, 10 SCDs and 11 aMCIs received a 2-week rTMS course of 5-day, once-daily. Cross-sectional analysis with the spectral dynamic causal model (spDCM) was used to analyze the DMN and CEN effective connectivity patterns of the three groups. Afterwards, longitudinal analysis was conducted on the changes in effective connectivity patterns and cognitive function before and after rTMS for SCD and aMCI, and the correlation between them was analyzed.

Results

Cross-sectional analysis showed different effective connectivity patterns in the DMN and CEN among the three groups. Longitudinal analysis showed that the effective connectivity pattern of the SCD had changed, accompanied by improvements in episodic memory. Correlation analysis indicated a negative relationship between effective connectivity from the left angular gyrus (ANG) to the anterior cingulate gyrus and the ANG.R to the right middle frontal gyrus, with visuospatial and executive function, respectively. In patients with aMCI, episodic memory and executive function improved, while the effective connectivity pattern remained unchanged.

Conclusion

This study demonstrates that PCUN-targeted rTMS in SCD regulates the abnormal effective connectivity patterns in DMN and CEN, thereby improving cognition function. Conversely, in aMCI, the mechanism of improvement may differ. Our findings further suggest that rTMS is more effective in preventing or delaying disease progression in the earlier stages of the AD spectrum.

Clinical Trial Registration

http://www.chictr.org.cn, ChiCTR2000034533.

Evaluation of Event-Related Potentials in Assessing Cognitive Functions of Adult Patients with Epilepsy of Unknown Etiology

Background: Cognitive impairment (CI) is an important consequence of epilepsy. The aim of the study was to assess cognitive performance in patients with epilepsy, using neuropsychological tests (NT) and event-related potentials (ERPs), with regard to demographic and clinical data. Methods: The study comprised 50 patients with epilepsy of unknown etiology and 46 healthy controls. Based on the NT results, the patients were divided into subgroups with/without CI. Parameters of P300 potential were compared between the patients and controls. P300 parameters and NT results were referred to demographics and clinical characteristics of epilepsy. Results: Based on the NT, 66% of patients were assigned as cognitively impaired. Median P300 latency was significantly (p < 0.0002) prolonged in the study group. Subgroups of patients with and without CI significantly (p < 0.034) differed in education level and vocational activity, duration of epilepsy, age at its onset and frequency of polytherapy. P300 parameters showed significant (p < 0.03) relationships with duration of epilepsy, type and frequency of seizures and polytherapy. Conclusions: Cognitive impairment and ERPs abnormalities occur in a majority of patients with epilepsy of unknown etiology. Characteristics of epilepsy and socioeconomic status are related to cognitive performance. ERPs may complement neuropsychological methods in the assessment of cognition in patients with epilepsy.

Psychological and Psychiatric Aspects of Brain and Spinal Cord Tumors

Central nervous system (CNS) tumors are mainly diagnosed by physical symptoms such as paralysis, visual field defect, seizure, and loss of consciousness. The psychological and psychiatric background of CNS tumors, whether in preoperative or postoperative period, has long been a neglected topic; however, lately, many authors and researchers have paid more attention to these manifestations. Neurocognition is a subset of parameters, including attention, memory, mood, emotions, language production, personality, executive function, problem-solving, calculation, and spatial cognition, making up the patient's cognitive performance. Also, it is worthy to say that neurocognition is considered a parameter of quality of life (QoL). Currently, we know that neurocognitive disorders are a group of symptoms presenting by the patients. These symptoms may be the first picture of CNS lesions, which result in incorrect treatment, a higher financial burden on the patient and health system, and finally, poorer QoL and performance scale if they are not diagnosed early. Psychological and psychiatric problems such as depression, anxiety, and phobia following the CNS tumors have two aspects. These may present before any treatment resulting from the tumoral mass effect, peritumoral edema, or cerebral tissue disruption due to the space-occupying lesion. On the other hand, we can see these features after a kind of therapy such as surgery, medical therapy, or adjuvant therapy. Sometimes, the CNS tumors lead to psychosocial complications postoperatively. Indeed, considering tumor surgery complications, some patients may find various degrees of deficits that make the patient isolated either socially or professionally. Obviously, the improvement rate and outcome of this specific situation depend on the mechanism of occurrence and its causes. For instance, postoperative symptom relief would be expected when the symptoms are related to the tumoral mass effect. Getting familiar with this constellation of the symptoms, realizing them, and then localizing them to the correct area of the CNS are very crucial. Accordingly, because of their importance in QoL, their influence on patient's survival even more than the extent of resection of the tumor, and somehow their ignorance, we will discuss different neurocognitive manifestations related to CNS tumors in this chapter.

The comparison of decision-making in ambiguous situations and galvanic skin responses as somatic markers in patients with posterior cortex epilepsy and mesial temporal lobe epilepsy with hippocampal sclerosis

INTRODUCTION

Decision-making behaviors of patients with mesial temporal lobe epilepsy (MTLE) is a subject that has been studied frequently. However, determining the neuropsychological profiles of patients with different types of epilepsy is also important. Our main purpose was to examine the decision-making behaviors of patients with posterior cortex epilepsy (PCE) through the assumptions of somatic marker hypothesis (SMH) and to compare their performances with those of a MTLE group and a control group.

METHOD

Participants comprised of 13 patients with PCE (mean age 30.92 ± 9.99 years); 14 patients with MTLE with hippocampal sclerosis (MTLE-HS) (mean age 25.53 ± 7.40 years) and 15 controls (mean age 24.60 ± 8.45 years). Decision-making performances were assessed with the Iowa gambling test (IGT) and anticipatory skin responses before each choice were recorded. A comprehensive neuropsychological test battery was also given to all participants in order to examine the relationship of decision-making with other cognitive functions.

RESULTS

Anticipatory responses before choosing from disadvantageous decks were significantly larger than choosing from advantageous decks in the PCE group (p = 0.00). No significant difference was found between the PCE and control group's total net scores. IGT total net scores was significantly correlated with Stroop test interference time (p = 0.03).

CONCLUSION

The study reveals that cognitive impairments of patients with PCE are not limited to brain's posterior areas' functions, and provides evidence for the current paradigm which understands epilepsy as a network disorder.

Functional Brain Connectivity in Mild Cognitive Impairment With Sleep Disorders: A Study Based on Resting-State Functional Magnetic Resonance Imaging

Purpose

To investigate the effect of sleep disorder (SD) on the changes of brain network dysfunction in mild cognitive impairment (MCI), we compared network connectivity patterns among MCI, SD, and comorbid MCI and sleep disorders (MCI-SD) patients using resting state functional magnetic resonance imaging (RS-fMRI).

Patients and Methods

A total of 60 participants were included in this study, 20 each with MCI, SD, or MCI-SD. And all participants underwent structural and functional MRI scanning. The default-mode network (DMN) was extracted by independent component analysis (ICA), and regional functional connectivity strengths were calculated and compared among groups.

Results

Compared to MCI patients, The DMN of MCI-SD patients demonstrated weaker functional connectivity with left middle frontal gyrus, right superior marginal gyrus, but stronger connectivity with the left parahippocampus, left precuneus and left middle temporal gyrus. Compared to the SD group, MCI-SD patients demonstrated weaker functional connectivity with right transverse temporal gyrus (Heschl’s gyrus), right precentral gyrus, and left insula, but stronger connectivity with posterior cerebellum, right middle occipital gyrus, and left precuneus.

Conclusion

Patients with MCI-SD show unique changes in brain network connectivity patterns compared to MCI or SD alone, likely reflecting a broader functional disconnection and the need to recruit more brain regions for functional compensation.

Benton judgment of line orientation test: Examination of four short forms

Objective: This multicenter retrospective study aimed at examining the clinical accuracy of four 15-item versions (Woodard's O and E; Quall's Q and S) of the original 30-item Benton judgment of line orientation test in a mixed clinical sample of 260 patients. It is a test frequently used as a measure of visuospatial processing. It has the advantage of requiring minimal motor skills, while a major weakness is the lengthy administration time.Method: An archival search was conducted within four in- and out-patient clinics. The frequency and magnitude of score differences were calculated to examine the equivalence of the short forms. We then checked the clinical accuracy of the short forms concerning classification of impaired, borderline, and non-impaired performance, according to NEURONORMA norms. After that, we calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa coefficients to assess the classification outcome of the short versions compared to the long version, when using a dichotomous classification (impaired versus intact performance).Results: When applying NEURONORMA norms, specificity (99.1%), PPV (93.1%), and kappa coefficient (0.87) were highest for version E. NPV (99.4%) and sensitivity (95.5%) were highest for version S, but the PPV of this version was relatively low (67.7%).Conclusions: We suggest use of version E when a short test is needed, as specificity, kappa coefficient, and PPV are highest for this version, while maintaining a high NPV (97.8%). However, future research should develop new normative data for these short 15-item versions.

The cognitive profile of occipital lobe epilepsy and the selective association of left temporal lobe hypometabolism with verbal memory impairment

We investigated the cognitive profile of structural occipital lobe epilepsy (OLE) and whether verbal memory impairment is selectively associated with left temporal lobe hypometabolism on [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET). Nine patients with OLE, ages 8-29 years, completed presurgical neuropsychological assessment. Composite measures were calculated for intelligence quotient (IQ), speed, attention, verbal memory, nonverbal memory, and executive functioning. In addition, the Wisconsin Card Sorting Test (WCST) was used as a specific measure of frontal lobe functioning. Presurgical FDG-PET was analyzed with statistical parametric mapping in 8 patients relative to 16 healthy volunteers. Mild impairments were evident for IQ, speed, attention, and executive functioning. Four patients demonstrated moderate or severe verbal memory impairment. Temporal lobe hypometabolism was found in seven of eight patients. Poorer verbal memory was associated with left temporal lobe hypometabolism (p = 0.002), which was stronger (p = 0.03 and p = 0.005, respectively) than the association of left temporal lobe hypometabolism with executive functioning or with performance on the WCST. OLE is associated with widespread cognitive comorbidity, suggesting cortical dysfunction beyond the occipital lobe. Verbal memory impairment is selectively associated with left temporal lobe hypometabolism in OLE, supporting a link between neuropsychological dysfunction and remote hypometabolism in focal epilepsy.