Cognitive control subprocess deficits and compensatory modulation mechanisms in patients with frontal lobe injury revealed by EEG markers: a basic study to guide brain stimulation

Association between the frontoparietal network, clinical symptoms and treatment response in individuals with untreated anorexia nervosa

Background

Anorexia nervosa (AN) has been characterised as a psychiatric disorder associated with increased control. Currently, it remains difficult to predict treatment response in patients with AN. Their cognitive abilities are known to be resistant to treatment. It has been established that the frontoparietal control network (FPCN) is the direct counterpart of the executive control network. Therefore, the resting-state brain activity of the FPCN may serve as a biomarker to predict treatment response in AN.

Aims

The study aimed to investigate the association between resting-state functional connectivity (RSFC) of the FPCN, clinical symptoms and treatment response in patients with AN.

Methods

In this case-control study, 79 female patients with AN and no prior treatment from the Shanghai Mental Health Center and 40 matched healthy controls (HCs) were recruited from January 2015 to March 2022. All participants completed the Questionnaire Version of the Eating Disorder Examination (version 6.0) to assess the severity of their eating disorder symptoms. Additionally, RSFC data were obtained from all participants at baseline by functional magnetic resonance imaging. Patients with AN underwent routine outpatient treatment at the 4th and 12th week, during which time their clinical symptoms were evaluated using the same measures as at baseline.

Results

Among the 79 patients, 40 completed the 4-week follow-up and 35 completed the 12-week follow-up. The RSFC from the right posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (dlPFC) increased in 79 patients with AN vs 40 HCs after controlling for depression and anxiety symptoms. By multiple linear regression, the RSFC of the PPC to the inferior frontal gyrus was found to be a significant factor for self-reported eating disorder symptoms at baseline and the treatment response to cognitive preoccupations about eating and body image, after controlling for age, age of onset and body mass index. The RSFC in the dlPFC to the middle temporal gyrus and the superior frontal gyrus may be significant factors in the treatment response to binge eating and loss of control/overeating in patients with AN.

Conclusions

Alterations in RSFC in the FPCN appear to affect self-reported eating disorder symptoms and treatment response in patients with AN. Our findings offer new insight into the pathogenesis of AN and could promote early prevention and treatment.

Resting-state electroencephalography delta and theta bands as compensatory oscillations in chronic neuropathic pain: a secondary data analysis

Chronic neuropathic pain (CNP) remains a significant clinical challenge, with complex neurophysiological underpinnings that are not fully understood. Identifying specific neural oscillatory patterns related to pain perception and interference can enhance our understanding and management of CNP. To analyze resting electroencephalography data from individuals with chronic neuropathic pain to explore the possible neural signatures associated with pain intensity, pain interference, and specific neuropathic pain characteristics. We conducted a secondary analysis from a cross-sectional study using electroencephalography data from a previous study, and Brief Pain Inventory from 36 patients with chronic neuropathic pain. For statistical analysis, we modeled a linear or logistic regression by dependent variable for each model. As independent variables, we used electroencephalography data with such brain oscillations: as delta, theta, alpha, and beta, as well as the oscillations low alpha, high alpha, low beta, and high beta, for the central, frontal, and parietal regions. All models tested for confounding factors such as age and medication. There were no significant models for Pain interference in general activity, walking, work, relationships, sleep, and enjoyment of life. However, the model for pain intensity during the past four weeks showed decreased alpha oscillations, and increased delta and theta oscillations were associated with decreased levels of pain, especially in the central area. In terms of pain interference in mood, the model showed high oscillatory Alpha signals in the frontal and central regions correlated with mood impairment due to pain. Our models confirm recent findings proposing that lower oscillatory frequencies, likely related to subcortical pain sources, may be associated with brain compensatory mechanisms and thus may be associated with decreased pain levels. On the other hand, higher frequencies, including alpha oscillations, may disrupt top-down compensatory mechanisms.

Consensus on rapid screening for prodromal Alzheimer's disease in China

Alzheimer's disease (AD) is a common cause of dementia, characterised by cerebral amyloid-β deposition, pathological tau and neurodegeneration. The prodromal stage of AD (pAD) refers to patients with mild cognitive impairment (MCI) and evidence of AD's pathology. At this stage, disease-modifying interventions should be used to prevent the progression to dementia. Given the inherent heterogeneity of MCI, more specific biomarkers are needed to elucidate the underlying AD's pathology. Although the uses of cerebrospinal fluid and positron emission tomography are widely accepted methods for detecting AD's pathology, their clinical applications are limited by their high costs and invasiveness, particularly in low-income areas in China. Therefore, to improve the early detection of Alzheimer's disease (AD) pathology through cost-effective screening methods, a panel of 45 neurologists, psychiatrists and gerontologists was invited to establish a formal consensus on the screening of pAD in China. The supportive evidence and grades of recommendations are based on a systematic literature review and focus group discussion. National meetings were held to allow participants to review, vote and provide their expert opinions to reach a consensus. A majority (two-thirds) decision was used for questions for which consensus could not be reached. Recommended screening methods are presented in this publication, including neuropsychological assessment, peripheral biomarkers and brain imaging. In addition, a general workflow for screening pAD in China is established, which will help clinicians identify individuals at high risk and determine therapeutic targets.