'Knock down the brain': a nonlinear analysis of electroencephalography to study the effects of sub-concussion in boxers.

BACKGROUND AND PURPOSE: Boxing is associated with a high risk of head injuries and increases the likelihood of chronic traumatic encephalopathy. This study explores the effects of sub-concussive impacts on boxers by applying both linear and nonlinear analysis methods to electroencephalogram (EEG) data. METHODS: Twenty-one boxers were selected (mean ± SD, age 28.38 ± 5.5 years; weight 67.55 ± 8.90 kg; years of activity 6.76 ± 5.45; education 14.19 ± 3.08 years) and divided into 'beginner' and 'advanced' groups. The Montreal Cognitive Assessment and the Frontal Assessment Battery were administered; EEG data were collected in both eyes-open (EO) and eyes-closed (EC) conditions during resting states. Analyses of EEG data included normalized power spectral density (nPSD), power law exponent (PLE), detrended fluctuation analysis and multiscale entropy. Statistical analyses were used to compare the groups. RESULTS: Significant differences in nPSD and PLE were observed between the beginner and advanced boxers, with advanced boxers showing decreased mean nPSD and PLE (nPSD 4-7 Hz, p = 0.013; 8-13 Hz, p = 0.003; PLE frontal lobe F3 EC, p = 0.010). Multiscale entropy analysis indicated increased entropy at lower frequencies and decreased entropy at higher frequencies in advanced boxers (F3 EC, p = 0.024; occipital lobe O1 EO, p = 0.029; occipital lobe O2 EO, p = 0.036). These changes are similar to those seen in Alzheimer's disease. CONCLUSION: Nonlinear analysis of EEG data shows potential as a neurophysiological biomarker for detecting the asymptomatic phase of chronic traumatic encephalopathy in boxers. This methodology could help monitor athletes' health and reduce the risk of future neurological injuries in sports.

Cognitive trajectories after surgery: Guideline hints for assessment and treatment.

Elderly patients who undergo major surgery (not-neurosurgical) under general anaesthesia frequently complain about cognitive difficulties, especially during the first weeks after surgical "trauma". Although recovery usually occurs within a month, about one out of four patients develops full-blown postoperative Neurocognitive disorders (NCD) which compromise quality of life or daily autonomy. Mild/Major NCD affect approximately 10% of patients from three months to one year after major surgery. Neuroinflammation has emerged to have a critical role in the postoperative NCDs pathogenesis, through microglial activation and the release of pro-inflammatory cytokines which increase blood-brain-barrier permeability, enhance movement of leukocytes into the central nervous system (CNS) and favour the neuronal damage. Moreover, pre-existing Mild Cognitive Impairment, alcohol or drugs consumption, depression and other factors, together with several intraoperative and post-operative sequelae, can exacerbate the severity and duration of NCDs. In this context it is crucial rely on current progresses in serum and CSF biomarker analysis to frame neuroinflammation levels, along with establishing standard protocol for neuropsychological assessment (with specific set of tools) and to apply cognitive training or neuromodulation techniques to reduce the incidence of postoperative NCDs when required. It is recommended to identify those patients who would need such preventive intervention early, by including them in pre-operative and post-operative comprehensive evaluation and prevent the development of a full-blown dementia after surgery. This contribution reports all the recent progresses in the NCDs diagnostic classification, pathogenesis discoveries and possible treatments, with the aim to systematize current evidences and provide guidelines for multidisciplinary care.

Correspondence effect driven by salient visual asymmetries in integral object stimuli.

The handle-to-hand correspondence effect consists of faster and more accurate responses when the responding hand is aligned with the handle side of an object tool, compared to when they lay on opposite sides. This effect has been attributed to the activation of affordances. Recent studies, however, claimed that it may depend on the spatial coding of the object on the basis of its visual asymmetry (location-coding account). Affordances are namely direct and meaningful relations between recognized objects and the observers' action system. Therefore, any manipulation that disrupts the body structure of object tools could potentially affect their identification and prevent the activation of affordances. The present study investigated the nature of the handle-to-hand correspondence effects by manipulating structural asymmetry and visual salience of object tools, while preserving their integrity that is, leaving unaltered the original possibilities to activate grasping affordances. Three experiments were run. Results were consistent with the location-coding account and claim for accurate control of visual asymmetries in object stimuli during investigation of affordance effects.

Do already grasped objects activate motor affordances?

This study investigated whether in a stimulus-response compatibility (SRC) task affordance effects in response to picture of graspable objects emerge when these objects appear as already grasped. It also assessed whether the observed effects could be explained as due to spatial compatibility between the most salient part in the object/display and the hand of response rather than to action potentiation. To this aim, we conducted three behavioural experiments in which participants were required to discriminate the vertical orientation (upright vs. inverted) of an object presented in the centre of the screen, while ignoring the right-left orientation of its handle. The object could be presented alone, as already grasped, as partially masked (Experiment 1) or with a human hand close to its graspable side (Experiment 2). In addition, to assess the role of perceptual salience, the object could be presented with a human hand or a non-biological (a geometrical shape) distractor located opposite to the object's graspable side. Results showed faster responses when the object's handle was located on the same side of the responding hand with a larger effect when upright objects were shown as already grasped (Experiment 1) or when a hand was displayed close to its handle (Experiment 2), and a smaller reversed effect when the hand or the geometrical shape was located opposite to the handled side (Experiment 3). We interpreted these findings as indicating that handle orientation effects emerging in SRC tasks may result from the interplay between motor affordance and spatial compatibility mechanisms.

The Effects of a New Integrated and Multidisciplinary Cognitive Rehabilitation Program Based on Mindfulness and Reminiscence Therapy in Patients with Parkinson's Disease and Mild Cognitive Impairment: A Pilot Study.

Background: Mindfulness trainings have shown promising results as treatment for behavioural symptoms in several pathologies. In addition, mindfulness protocols induced an improvement in memory and attention. Therefore, mindfulness could be an effective intervention for patients affected by Parkinson's disease (PD) and mild cognitive impairment (MCI), who are characterized by both behavioural and cognitive dysfunctions. Methods: We assessed differences in Montreal Cognitive Assessment (MoCA) scores and in Beck Depression Inventory II (BDI-II) scores in patients affected by PD and MCI enrolled in two different rehabilitation programs (an experimental vs. an usual structured program for cognitive rehabilitation). Participants in the experimental group (MILC-tr) underwent innovative rehabilitation program involving mindfulness and reminiscence activities. Assessments were performed before (T0) and at the end of the rehabilitation program (T1). Results: Friedman test showed a significant improvement between timepoints in MoCA global score (x2 = 4.000, p = 0.046), MoCA memory sub-scale score (x2 = 4.571, p = 0.033), and BDI-II cognitive and affective factors (x2 = 4.000, p = 0.046) only for patients in MILC-tr group. Mann-Whitney test showed a significant difference between group comparing differences in Δ scores between T0 and T1 in the MoCA memory sub-scale score (U = 190.50, p = 0.035). Conclusions: Mindfulness-based rehabilitation programs could be effective in patients affected by PD and MCI.

Relationship between Reaction Times and Post-COVID-19 Symptoms Assessed by a Web-Based Visual Detection Task.

Long-COVID is a clinical condition in which patients affected by SARS-CoV-2 usually report a wide range of physical and cognitive symptoms from 3 to 6 months after the infection recovery. The aim of the current study was to assess the link between self-reported long-COVID symptoms and reaction times (RTs) in a self-administered Visual Detection Task (VDT) in order to identify the predictor symptoms of the slowing in reaction times to determine attention impairment. In total, 362 participants (age (mean ± S.D.: 38.56 ± 13.14); sex (female-male: 73.76-26.24%)) responded to a web-based self-report questionnaire consisting of four sections: demographics, disease-related characteristics, and medical history questions. The final section consisted of a 23 item 5-point Likert-scale questionnaire related to long-term COVID-19 symptoms. After completing the questionnaire, subjects performed a VDT on a tablet screen to assess reaction times (RTs). An exploratory factorial analysis (EFA) was performed on the 23 long-COVID symptom questions, identifying 4 factors (cognition, behavior, physical condition, presence of anosmia and/or ageusia). The most important predictors of RTs were cognition and physical factors. By dissecting the cognitive and physical factors, learning, visual impairment, and headache were the top predictors of subjects' performance in the VDT. Long-COVID subjects showed higher RTs in the VDT after a considerable time post-disease, suggesting the presence of an attention deficit disorder. Attention impairment due to COVID-19 can be due to the presence of headaches, visual impairments, and the presence of cognitive problems related to the difficulty in learning new activities. The link between the slowing of reaction times and physical and cognitive symptoms post-COVID-19 suggests that attention deficit disorder is caused by a complex interaction between physical and cognitive symptoms. In addition, the study provides evidence that RTs in a VDT represent a reliable measure to detect the presence of long-COVID neurological sequelae.

Modeling Electric Fields in Transcutaneous Spinal Direct Current Stimulation: A Clinical Perspective.

Clinical findings suggest that transcutaneous spinal direct current stimulation (tsDCS) can modulate ascending sensitive, descending corticospinal, and segmental pathways in the spinal cord (SC). However, several aspects of the stimulation have not been completely understood, and realistic computational models based on MRI are the gold standard to predict the interaction between tsDCS-induced electric fields and anatomy. Here, we review the electric fields distribution in the SC during tsDCS as predicted by MRI-based realistic models, compare such knowledge with clinical findings, and define the role of computational knowledge in optimizing tsDCS protocols. tsDCS-induced electric fields are predicted to be safe and induce both transient and neuroplastic changes. This could support the possibility to explore new clinical applications, such as spinal cord injury. For the most applied protocol (2-3 mA for 20-30 min, active electrode over T10-T12 and the reference on the right shoulder), similar electric field intensities are generated in both ventral and dorsal horns of the SC at the same height. This was confirmed by human studies, in which both motor and sensitive effects were found. Lastly, electric fields are strongly dependent on anatomy and electrodes' placement. Regardless of the montage, inter-individual hotspots of higher values of electric fields were predicted, which could change when the subjects move from a position to another (e.g., from the supine to the lateral position). These characteristics underlines the need for individualized and patient-tailored MRI-based computational models to optimize the stimulation protocol. A detailed modeling approach of the electric field distribution might contribute to optimizing stimulation protocols, tailoring electrodes' configuration, intensities, and duration to the clinical outcome.