Tracing the path of disruption: C isotope applications in traumatic brain injury-induced metabolic dysfunction.

Cerebral metabolic dysfunction is a critical pathological hallmark observed in the aftermath of traumatic brain injury (TBI), as extensively documented in clinical investigations and experimental models. An in-depth understanding of the bioenergetic disturbances that occur following TBI promises to reveal novel therapeutic targets, paving the way for the timely development of interventions to improve patient outcomes. The C isotope tracing technique represents a robust methodological advance, harnessing biochemical quantification to delineate the metabolic trajectories of isotopically labeled substrates.

A giant foramen of Vesalius: case report.

Anatomical variations identified at the skull base can result in challenges to the clinician. For example, the anatomy of the foramen ovale and its neighboring structures is critical knowledge for the surgeon who performs transcutaneous approaches to the foramen ovale for treating patients with trigeminal neuralgia. One nearby structure that can compound invasive procedures and potentially result in complications is the foramen of Vesalius.

Giant dural arteriovenous fistula in an infant.

Dural arteriovenous fistulas (dAVFs) are commonly encountered by the neurosurgeon. Herein, we present a case illustration of an infant presenting with an extremely large fistula that took up a significant part of the intracranial volume. A one-month-old female presented with irritability and failure to thrive.

'Haste makes waste': The tradeoff between walking speed and target-stepping accuracy.

Background: When environmental conditions require accurate foot placement during walking (e.g., on a rough path), we typically walk slower to avoid tripping, slipping or stumbling.

A Re-Appraisal of the Effect of Amplitude on the Stability of Interlimb Coordination Based on Tightened Normalization Procedures.

The stability of rhythmic interlimb coordination is governed by the coupling between limb movements. While it is amply documented how coordinative performance depends on movement frequency, theoretical considerations and recent empirical findings suggest that interlimb coupling (and hence coordinative stability) is actually mediated more by movement amplitude. Here, we present the results of a reanalysis of the data of Post, Peper, and Beek (2000), which were collected in an experiment aimed at teasing apart the effects of frequency and amplitude on coordinative stability of both steady-state and perturbed in-phase and antiphase interlimb coordination.

Virtual Footprints Can Improve Walking Performance in People With Parkinson's Disease.

In Parkinson's disease (PD) self-directed movement, such as walking, is often found to be impaired while goal directed movement, such as catching a ball, stays relatively unaltered. This dichotomy is most clearly observed when sensory cueing techniques are used to deliver patterns of sound and/or light which in turn act as an external guide that improves gait performance. In this study we developed visual cues that could be presented in an immersive, interactive virtual reality (VR) environment.

Crossing Virtual Doors: A New Method to Study Gait Impairments and Freezing of Gait in Parkinson's Disease.

Studying freezing of gait (FOG) in the lab has proven problematic. This has primarily been due to the difficulty in designing experimental setups that maintain high levels of ecological validity whilst also permitting sufficient levels of experimental control. To help overcome these challenges, we have developed a virtual reality (VR) environment with virtual doorways, a situation known to illicit FOG in real life.

Autism in Action: Reduced Bodily Connectedness during Social Interactions?

Autism is a lifelong disorder, defined by deficits in social interactions and flexibility. To date, diagnostic markers for autism primarily include limitations in social behavior and cognition. However, such tests have often shown to be inadequate for individuals with autism who are either more cognitively able or intellectually disabled.

Attentional costs of walking are not affected by variations in lateral balance demands in young and older adults.

Increased attentional costs of walking in older adults have been attributed to age-related changes in visuomotor and/or balance control of walking. The present experiment was conducted to examine the hypothesis that attentional costs of walking vary with lateral balance demands during walking in young and older adults. Twenty young and twenty older adults walked on a treadmill at their preferred walking speed under five conditions: unconstrained normal walking, walking on projected visual lines corresponding to either the participant's preferred step width or 50% thereof (i.

Does interpersonal movement synchronization differ from synchronization with a moving object?

We examined whether movement synchronization is different during coordination with another person than during coordination with a moving object. In addition, the influence of belief in the other person's agency was assessed. Participants synchronized their lower-arm movements with a computer-controlled rhythmic reference movement.

Effects of aging and dual tasking on step adjustments to perturbations in visually cued walking.

Making step adjustments is an essential component of walking. However, the ability to make step adjustments may be compromised when the walker's attentional capacity is limited. This study compared the effects of aging and dual tasking on step adjustments in response to stepping-target perturbations during visually cued treadmill walking.

Attuning one's steps to visual targets reduces comfortable walking speed in both young and older adults.

Comfortable walking speed (CWS) is indicative of clinically relevant factors in the elderly, such as fall risk and mortality. Standard CWS tests involve walking on a straight, unobstructed surface, while in reality surfaces are uneven and cluttered and so walkers rely on visually guided adaptations to avoid trips or slips. Hence, the predictive value of CWS may be expected to increase when assessed for walking in more realistic (visually guided) conditions.

Intended and unintended (sensory-)motor coupling between the affected and unaffected upper limb in complex regional pain syndrome.

Background: Motor dysfunction in complex regional pain syndrome (CRPS) has been associated with bilateral malfunction of sensory and motor circuits, which hints at abnormal coupling between the affected and the contralateral unaffected limb. In addition, clinical observations suggest that motor performance may depend on the (voluntary or automatic) context in which movements are executed. The present study aimed to examine the role of voluntary and automatic aspects of interlimb coupling in CRPS.

Unilateral and bilateral upper-limb training interventions after stroke have similar effects on bimanual coupling strength.

Background: Bilateral training in poststroke upper-limb rehabilitation is based on the premise that simultaneous movements of the nonparetic upper limb facilitate performance and recovery of paretic upper-limb function through neural coupling effects.

Objective: To determine whether the degree of coupling between both hands is higher after bilateral than after unilateral training and control treatment.

Methods: In a single-blinded randomized controlled trial, we investigated rhythmic interlimb coordination after unilateral (mCIMT) and bilateral (mBATRAC) upper-limb training and a dose-matched control treatment (DMCT) in 60 patients suffering from stroke.

Attentional costs of visually guided walking: effects of age, executive function and stepping-task demands.

During walking, attention needs to be flexibly allocated to deal with varying environmental constraints. This ability may be affected by aging and lower overall executive function. The present study examined the influence of aging and executive function on the attentional costs of visually guided walking under different task demands.

Evaluation of mirrored muscle activity in patients with Complex Regional Pain Syndrome.

Objective: Motor dysfunction in Complex Regional Pain Syndrome (CRPS) has been associated with bilateral changes in central motor processing, suggesting abnormal coupling between the affected and unaffected limb. We evaluated the occurrence of involuntary muscle activity in a limb during voluntary movements of the contralateral limb (i.e.

Individual contributions to (re-)stabilizing interpersonal movement coordination.

Interpersonal movement coordination is characterized by stable coordination patterns. We examined the extent to which the two individuals within a dyad contributed to the stabilization of a shared coordination pattern. Within each dyad, the two participants coordinated rhythmic movements of their right lower arms in either in-phase or antiphase.

Motor dysfunction of complex regional pain syndrome is related to impaired central processing of proprioceptive information.

Unlabelled: Our understanding of proprioceptive deficits in complex regional pain syndrome (CRPS) and its potential contribution to impaired motor function is still limited. To gain more insight into these issues, we evaluated accuracy and precision of joint position sense over a range of flexion-extension angles of the wrist of the affected and unaffected sides in 25 chronic CRPS patients and in 50 healthy controls. The results revealed proprioceptive impairment at both the patients' affected and unaffected sides, characterized predominantly by overestimation of wrist extension angles.

Unilateral versus bilateral upper limb training after stroke: the Upper Limb Training After Stroke clinical trial.

Background And Purpose: Unilateral and bilateral training protocols for upper limb rehabilitation after stroke represent conceptually contrasting approaches with the same ultimate goal. In a randomized controlled trial, we compared the merits of modified constraint-induced movement therapy, modified bilateral arm training with rhythmic auditory cueing, and a dose-matched conventional treatment. Modified constraint-induced movement therapy and modified bilateral arm training with rhythmic auditory cueing targeted wrist and finger extensors, given their importance for functional recovery.

Phase entrainment strength scales with movement amplitude disparity.

In the current study, we examined whether coupling influences resulting from unintended afference-based phase entrainment are affected by movement amplitude as such or by the amplitude relation between the limbs. We assessed entrainment strength by studying how passive movements of the contralateral hand influenced unimanual coordination with a metronome. Results showed that amplitude as such did not affect entrainment strength, whereas the amplitude relation between the hands did.

Deficient muscle activation in patients with Complex Regional Pain Syndrome and abnormal hand postures: an electromyographic evaluation.

Objective: Motor abnormalities in Complex Regional Pain Syndrome (CRPS) are common and often characterized by a restricted active range of motion (AROM) and an increased resistance to passive movements, whereby the affected body part preferably adopts an abnormal posture. The objective of the present study was to obtain a better understanding of the factors that are associated with these abnormal postures and limitations of the AROM, and to investigate whether these motor impairments reflect dystonia.

Methods: We evaluated characteristics of surface EMG of the flexor carpi radialis and extensor carpi radialis muscles during active maintenance of various flexion-extension postures of the wrist of the affected and unaffected side in 15 chronic CRPS patients, and in 15 healthy controls.

Biases in rhythmic sensorimotor coordination: effects of modality and intentionality.

Sensorimotor biases were examined for intentional (tracking task) and unintentional (distractor task) rhythmic coordination. The tracking task involved unimanual tracking of either an oscillating visual signal or the passive movements of the contralateral hand (proprioceptive signal). In both conditions the required coordination patterns (isodirectional and mirror-symmetric) were defined relative to the body midline and the hands were not visible.

Match and mismatch between objective and subjective improvements in upper limb function after stroke.

Purpose: To identify stroke patients showing a match between an objectively meaningful improvement in upper-limb motor capacity and subjectively meaningful improvement in upper-limb performance after stroke, as well as determinants of matching and non-matching.

Methods: Changes in upper-limb capacity in 39 stroke patients were measured over 17 weeks using the Action Research Arm Test (ARAT). Subjective change was measured with the Stroke Impact Scale Hand domain (SIS-Hand) and the Motor Activity Log (MAL).

Bimanual training for children with cerebral palsy: exploring the effects of Lissajous-based computer gaming.

Objective: Hemiplegic cerebral palsy often results in impaired bimanual coordination, partly due to strong coupling between the arms. We aimed at inducing more flexibility in this coupling, to improve bimanual coordination.

Methods: We designed computer games involving simple perceptual goals, based on Lissajous feedback.

Learning a new bimanual coordination pattern: interlimb interactions, attentional focus, and transfer.

Because bimanual coordinative stability is governed by interlimb coupling, we examined how learning a new pattern (90°) was reflected in changes in the underlying interlimb interactions. Three interlimb interaction sources were distinguished: integrated timing of feedforward control signals, error corrections based on perceived relative phase, and phase entrainment by contralateral afference. By comparing 4 tasks that involve these interactions to a different extent, changes in the stabilizing contributions of these coupling sources could be studied.