Cortical reorganization after hand immobilization: the beta qEEG spectral coherence evidences

Bröstrom Repair Review

Since its introduction in 1966, the Bröstrom repair has been the workhorse for the treatment of chronic ankle instability. The procedure has expanded with the advent of arthroscopy, ultrasound, and other techniques. Because chronic ankle sprains/instability pose a barrier to athletes who perform high-level activities for a living, discussions concerning postoperative recovery and return to play criteria are important. Here we present an update on the Bröstrom-Gould procedure from preoperative management to return to play.Level of Evidence: Level V.

Hand laterality recognition in distal radius and/or ulna fracture

INTRODUCTION

Hand laterality, an important ability to determine the orientation of a limb is common to get affected after short term immobilization. Distal radius and/or ulna fracture is a commonly encountered fracture resulting from upper-limb trauma. Conservative treatment using closed reduction and plaster cast application to immobilize the joint remains choice of treatment over surgery in the treatment of these fractures. There is a paucity of literature reporting impairment in hand laterality after long term immobilization as commonly performed in patients with distal radius and/or ulna fractures. Understanding effect of immobilization on hand laterality in distal-end radius/ulna fractures warranted present investigation.

PURPOSE

To evaluate hand laterality based on the accuracy and response time for hand determination after plaster cast removal in distal radius and/or ulna fracture.

STUDY DESIGN

Prospective cross sectional study.

METHODOLOGY

Subjects (n = 60, age range = 40-59 years, females (n) = 28 and males (n) = 32) were shown 24 real-hand images with various degrees of angular rotation and instructed to identify the hand as left and/or right. Accuracy (% correctly identified) and Response time (milliseconds to identify left or right hand in the image) of motor imagery during hand laterality task were recorded. Pain intensity before and after the hand laterality task were noted using Visual Analogue Scale. Repeated measures of ANOVA and t tests were used to analyze the accuracy and response times among two groups.

RESULTS

The experimental group showed significantly (P < .05) lower accuracy and longer response time as compared to the control group. No significant difference in the accuracy and response time were noted in the immobilization of the dominant and the non-dominant hand within the experimental group (P > .05). Also, there was no change in pain pre- to post-hand laterality task.

CONCLUSION

Findings of this study could aid in enhancing the understanding of post-immobilization effect on hand laterality and open new arenas for assessment and rehabilitation of distal-end radius and/or ulna fractures where immobilization is the principal treatment.

Male practitioners of physical activity present lower absolute power of beta band in time perception test

Cortical changes resulting from physical activity and differences in the estimation of the time of practitioners and non-practitioners of physical activity have already been documented. However, there aren't studies that compare the cortical responses of the time estimate between these groups. Therefore, this study aimed to investigate the influence of the level of physical activity in time estimation and beta band activity in frontal regions, specifically in the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, and parietal cortex during the task of estimating time in practitioners and non-practitioners of physical activity. After characterizing the sample, the signal was captured using an electroencephalogram during a task to estimate the time of four intervals of supraseconds. The results indicated that the practitioners of physical activity had lower errors in the evaluation of time for the intervals of 1 s, 7 s, and 9 s. The beta band showed less activity among practitioners of physical activity. The correlation between task performance and the absolute power of the beta band proved to be positive in the task of estimating time in the 7 s, and 9 s intervals. It was concluded that participants involved in the regular practice of physical activity showed underestimation in the temporal judgment and lower absolute power of the beta band during the time estimate.

Clinical Application of Combined EEG-qEEG Functional Neuroimaging in the Practice of Pediatric Neuroscience: A Personal Perspective

This brief article is an overview of my personal experience over the past almost 10 years of the clinical use of EEG and quantitative EEG (qEEG) functional neuroimaging in a busy pediatric neurology practice. The concomitant use of surface EEG and functional electromagnetic EEG neuroimaging/qEEG in clinical practice provides significant additional clinical and neurophysiologic information. The qEEG is a noninvasive, inexpensive, portable technique with high temporal resolution (milliseconds) and improving spatial resolution (down to 3 mm³) and is an appropriate and validated tool for investigation of abnormal brain dynamics and connectivity of neuronal networks in clinical disorders of the brain. This article describes the daily applicability and utility of this modality in assisting diagnosis and clinical management of patients with a wide variety of presenting symptoms, including headaches, tics, autism spectrum disorder, inattention, sleep dysregulation, anxiety, and depression. The ease of data acquisition and analysis in clinical practices, coupled with skilled interpretation and clinical application, makes this tool one of the most valuable clinical tools to complement a thorough history and examination process.

Modulating dream experience: Noninvasive brain stimulation over the sensorimotor cortex reduces dream movement

Recently, cortical correlates of specific dream contents have been reported, such as the activation of the sensorimotor cortex during dreamed hand clenching. Yet, despite a close resemblance of such activation patterns to those seen during the corresponding wakeful behaviour, the causal mechanisms underlying specific dream contents remain largely elusive. Here, we aimed to investigate the causal role of the sensorimotor cortex in generating movement and bodily sensations during REM sleep dreaming. Following bihemispheric transcranial direct current stimulation (tDCS) or sham stimulation, guided by functional mapping of the primary motor cortex, naive participants were awakened from REM sleep and responded to a questionnaire on bodily sensations in dreams. Electromyographic (EMG) and electroencephalographic (EEG) recordings were used to quantify physiological changes during the preceding REM period. We found that tDCS, compared to sham stimulation, significantly decreased reports of dream movement, especially of repetitive actions. Other types of bodily experiences, such as tactile or vestibular sensations, were not affected by tDCS, confirming the specificity of stimulation effects to movement sensations. In addition, tDCS reduced EEG interhemispheric coherence in parietal areas and affected the phasic EMG correlation between both arms. These findings show that a complex temporal reorganization of the motor network co-occurred with the reduction of dream movement, revealing a link between central and peripheral motor processes and movement sensations of the dream self. tDCS over the sensorimotor cortex interferes with dream movement during REM sleep, which is consistent with a causal contribution to dream experience and has broader implications for understanding the neural basis of self-experience in dreams.

Dopaminergic drugs alter beta coherence during motor imagery and motor execution in healthy adults

BACKGROUND

Motor Imagery (MI) represents the cognitive component of the movement and recruits dopaminergic systems.

OBJECTIVE

To investigate the role of dopaminergic system through the action of methylphenidate and risperidone over beta coherence during execution, action observation and motor imagery.

METHODS

Electroencephalography (EEG) data were recorded before and after the substance intake. For statistical analysis, a three-way ANOVA was used to identify changes in beta coherence induced by the group, task and the moment variables. Statistical significance was set at p≤0.007.

RESULTS

We found a main effect for group for C3/CZ, and a main effect for task for CZ/C4 pairs of electrodes. Furthermore, significant differences were found in the post-drug administration between groups for C3/CZ pair of electrodes, and between task for C4/CZ pair of electrodes.

CONCLUSION

The administration of methylphenidate and risperidone was able to produce electrocortical changes of the cortical central regions, even when featuring antagonistic effects on the dopaminergic pathways. Moreover, the execution task allowed beta-band modulation increase.

Motor Imagery Training During Arm Immobilization Prevents Corticomotor Idling: An EEG Resting-State Analysis

Limb disuse causes overt, measurable alterations in motor functions. Motor imagery (MI) practice has been used as a behavioral strategy to prevent motor impairments due to limb disuse or immobilization. Yet, how MI operates at the neural level in the context of short-term limb immobilization remains understudied. We hypothesized that MI treatment applied during 12 h of arm immobilization prevents immobilization-related changes in resting-state electroencephalographic (rsEEG) power and functional connectivity. Fourteen participants first underwent rsEEG after 12 h of normal motor activity (without immobilization). Then, rsEEG recording was performed after 12 h of arm immobilization either with MI treatment or without, each condition separated by 1 week, according to a randomized within-subjects design. MI treatment consisted in performing varied visual and kinaesthetic MI exercises (5 sessions of 15 min every two hours). The results showed that in the delta, theta, alpha and beta frequency bands, interhemispheric difference in sensors power over the motor cortex (i.e. C3 vs. C4) was reduced after arm immobilization, while it did not change when MI treatment was delivered during the immobilization period. Moreover, functional connectivity across the sensors-network in the delta (1-4 Hz) and alpha (8-12 Hz) frequency bands decreased after immobilization while it was restored by MI treatment. To conclude, MI counteracts functional neural changes within and between motor regions in the context of limb immobilization. Practical applications for motor rehabilitation strategies, particularly in stroke patients, are also discussed.

Rehabilitation after anatomical ankle ligament repair or reconstruction

The selection, implementation of and adherence to a post-operative regimen are all essential in order to achieve the best outcomes after ankle ligament surgery. The purpose of this paper is to present a best-evidence approach to this, with grounding in basic science and a consensus opinion from the members of the ESSKA-AFAS Ankle Instability Group. Basic science and clinical evidence surrounding tissue healing after surgical repair or reconstruction of the ligaments as well as around the re-establishment of sensorimotor control are reviewed. A consensus opinion based on this evidence as to the recommended rehabilitation protocol after ankle ligament surgery was then obtained from the members of the ESSKA-AFAS Ankle Instability Group. Rehabilitation recommendations are presented for the initial post-operative period, the early recovery phase and a goal-orientated late rehabilitation and return-to-sport phase. This paper presents practical, evidenced-based guidelines for rehabilitation and return to activity after lateral ankle ligament surgery.

Rehabilitation after anatomical ankle ligament repair or reconstruction

The selection, implementation of and adherence to a post-operative regimen are all essential in order to achieve the best outcomes after ankle ligament surgery. The purpose of this paper is to present a best-evidence approach to this, with grounding in basic science and a consensus opinion from the members of the ESSKA-AFAS Ankle Instability Group. Basic science and clinical evidence surrounding tissue healing after surgical repair or reconstruction of the ligaments as well as around the re-establishment of sensorimotor control are reviewed. A consensus opinion based on this evidence as to the recommended rehabilitation protocol after ankle ligament surgery was then obtained from the members of the ESSKA-AFAS Ankle Instability Group. Rehabilitation recommendations are presented for the initial post-operative period, the early recovery phase and a goal-orientated late rehabilitation and return-to-sport phase. This paper presents practical, evidenced-based guidelines for rehabilitation and return to activity after lateral ankle ligament surgery.

Assessing vibratory stimulation-induced cortical activity during a motor task--A randomized clinical study

Effects of vibratory stimulation on motor performance have been widely investigated. Many theories have been applied, in order to evaluate its influence on individuals; however, very few studies have researched vibratory stimulation-induced cortical behavior. The aim of the present study is to investigate behavioral changes, such as reaction time and index finger movements, as well as electrophysiological changes, using beta band absolute power, in subjects submitted to vibratory stimulation. For this study, 30 healthy subjects were randomly selected and divided into two groups, experimental and control, and were submitted to a right index finger task, before and after vibratory stimulation, which was applied to the right upper limb, while their standard cerebral activity was recorded through electroencephalogram. No significant difference was found among behavioral variables. On the other hand, beta band absolute power significantly increased in the experimental group for the C3, C4 and P4 derivations, while it decreased at P3. The results suggest that electrophysiological changes were induced by vibratory stimulation, while reaction time and task-related movements were not affected by it.

Changes in the theta band coherence during motor task after hand immobilization

Many different factors can temporarily or permanently impair movement and impairs cortical organization, e.g. hand immobilization. Such changes have been widely studied using electroencephalography. Within this context, we have investigated the immobilization effects through the theta band coherence analysis, in order to find out whether the immobilization period causes any changes in the inter and intra-hemispheric coherence within the cerebral cortex, as well as to observe whether the theta band provides any information about the neural mechanisms involved during the motor act. We analyzed the cortical changes that occurred after 48 hours of hand immobilization. The theta band coherence was study through electroencephalography in 30 healthy subjects, divided into two groups (control and experimental). Within both groups, the subjects executed a task involving flexion and extension of the index finger, before and after 48 hours. The experimental group, however, was actually submitted to hand immobilization. We were able to observe an increase in the coupling within the experimental group in the frontal, parietal and temporal regions, and a decrease in the motor area. In order to execute manual tasks after some time of movement restriction, greater coherence is present in areas related to attention, movement preparation and sensorimotor integration processes. These results may contribute to a detailed assessment of involved neurophysiological mechanism in motor act execution.