Scholars@Duke
Charalambos Costas Charalambous

Charalambos Costas Charalambous

Medical Instructor in the Department of Neurology
Neurology, Stroke and Vascular Neurology
charalambos.charalambous@duke.edu
DUMC Box 3824, Durham, NC 27710
40 Duke Medicine Circle, Box 3824, Durham, NC 27710
Office hours Monday-Friday: 9-12PM EST  

Selected Publications

Alpha and beta/low-gamma frequency bands may have distinct neural origin and function during post-stroke walking.

Journal Article Exp Brain Res · October 2024 Plantarflexors provide propulsion during walking and receive input from both corticospinal and corticoreticulospinal tracts, which exhibit some frequency-specificity that allows potential differentiation of each tract's descending drive. Given that stroke ... Full text Link to item Cite

A novel biomechanical indicator for impaired ankle dorsiflexion function during walking in individuals with chronic stroke.

Journal Article Gait Posture · January 2024 BACKGROUND: Ankle dorsiflexion function during swing phase contributes to foot clearance and plays an important role in walking ability post-stroke. Commonly used biomechanical measures such as foot clearance and ankle joint excursion have limited ability ... Full text Link to item Cite

A 12-week in-phase bilateral upper limb exercise protocol promoted neuroplastic and clinical changes in people with relapsing remitting multiple sclerosis: A registered report randomized single-case concurrent multiple baseline study.

Journal Article PLoS One · 2024 INTRODUCTION: Relapsing-Remitting Multiple Sclerosis manifests various motor symptoms including impairments in corticospinal tract integrity, whose symptoms can be assessed using transcranial magnetic stimulation. Several factors, such as exercise and inte ... Full text Link to item Cite

The distribution of transcallosal inhibition to upper extremity muscles is altered in chronic stroke.

Journal Article J Neurol Sci · July 15, 2023 OBJECTIVE: To determine if the distribution of transcallosal inhibition (TI) acting on proximal and distal upper extremity muscles is altered in chronic stroke. METHODS: We examined thirteen healthy controls and sixteen mildly to moderately impaired chroni ... Full text Link to item Cite

Association of Brain Age, Lesion Volume, and Functional Outcome in Patients With Stroke.

Journal Article Neurology · May 16, 2023 BACKGROUND AND OBJECTIVES: Functional outcomes after stroke are strongly related to focal injury measures. However, the role of global brain health is less clear. In this study, we examined the impact of brain age, a measure of neurobiological aging derive ... Full text Link to item Cite

Investigation of in-phase bilateral exercise effects on corticospinal plasticity in relapsing remitting multiple sclerosis: A registered report single-case concurrent multiple baseline design across five subjects.

Journal Article PLoS One · 2023 Relapsing-remitting Multiple Sclerosis is the most common demyelinating neurodegenerative disease and is characterized by periods of relapses and generation of various motor symptoms. These symptoms are associated with the corticospinal tract integrity, wh ... Full text Link to item Cite

Chronic Stroke Sensorimotor Impairment Is Related to Smaller Hippocampal Volumes: An ENIGMA Analysis.

Journal Article J Am Heart Assoc · May 17, 2022 Background Persistent sensorimotor impairments after stroke can negatively impact quality of life. The hippocampus is vulnerable to poststroke secondary degeneration and is involved in sensorimotor behavior but has not been widely studied within the contex ... Full text Link to item Cite

Is there frequency-specificity in the motor control of walking? The putative differential role of alpha and beta oscillations.

Journal Article Front Syst Neurosci · 2022 Alpha and beta oscillations have been assessed thoroughly during walking due to their potential role as proxies of the corticoreticulospinal tract (CReST) and corticospinal tract (CST), respectively. Given that damage to a descending tract after stroke can ... Full text Link to item Cite

Corticoreticulospinal tract neurophysiology in an arm and hand muscle in healthy and stroke subjects.

Journal Article J Physiol · August 2021 KEY POINTS: The corticoreticulospinal tract (CReST) is a descending motor pathway that reorganizes after corticospinal tract (CST) injury in animals. In humans, the pattern of CReST innervation to upper limb muscles has not been carefully examined in healt ... Full text Link to item Cite

Comparing cortico-motor hotspot identification methods in the lower extremities post-stroke: MEP amplitude vs. latency.

Journal Article Neurosci Lett · May 29, 2021 Transcranial magnetic stimulation (TMS) is a technique used to probe and measure cortico-motor responses of the nervous system. However, lower extremity (LE) specific methodology has been slow to develop. In this retrospective analysis, we investigated wha ... Full text Link to item Cite

Smaller spared subcortical nuclei are associated with worse post-stroke sensorimotor outcomes in 28 cohorts worldwide.

Journal Article Brain Commun · 2021 Up to two-thirds of stroke survivors experience persistent sensorimotor impairments. Recovery relies on the integrity of spared brain areas to compensate for damaged tissue. Deep grey matter structures play a critical role in the control and regulation of ... Full text Link to item Cite

Athletes after anterior cruciate ligament reconstruction demonstrate asymmetric intracortical facilitation early after surgery.

Journal Article J Orthop Res · January 2021 Quadriceps dysfunction persists after anterior cruciate ligament reconstruction (ACLR), yet the etiology remains elusive. Inhibitory and facilitatory intracortical networks (ie, intracortical excitability) may be involved in quadriceps dysfunction, yet the ... Full text Link to item Cite

Examination of Corticospinal and Spinal Reflexive Excitability During the Course of Postoperative Rehabilitation After Anterior Cruciate Ligament Reconstruction.

Journal Article J Orthop Sports Phys Ther · September 2020 OBJECTIVE: To investigate corticospinal and spinal reflexive excitability and quadriceps strength in healthy athletes and athletes after anterior cruciate ligament reconstruction (ACLR) over the course of rehabilitation. DESIGN: Prospective cohort study. M ... Full text Link to item Cite

Individualized Responses to Ipsilesional High-Frequency and Contralesional Low-Frequency rTMS in Chronic Stroke: A Pilot Study to Support the Individualization of Neuromodulation for Rehabilitation.

Journal Article Front Hum Neurosci · 2020 Background: In this pilot study, we examined the effects of ipsilesional high-frequency rTMS (iHF-rTMS) and contralesional low-frequency rTMS (cLF-rTMS) applied via a double-cone coil on neurophysiological and gait variables in patients with chronic stroke ... Full text Link to item Cite

A single high-intensity exercise bout during early consolidation does not influence retention or relearning of sensorimotor locomotor long-term memories.

Journal Article Exp Brain Res · November 2019 A single exercise bout has been found to improve the retention of a skill-based upper extremity motor task up to a week post-practice. This effect is the greatest when exercise intensity is high and exercise is administered immediately after motor practice ... Full text Link to item Cite

A short bout of high-intensity exercise alters ipsilesional motor cortical excitability post-stroke.

Journal Article Top Stroke Rehabil · September 2019 Background: Acute exercise can increase motor cortical excitability and enhance motor learning in healthy individuals, an effect known as exercise priming. Whether it has the same effects in people with stroke is unclear. Objectives: The objective of this ... Full text Link to item Cite

Bilateral Assessment of the Corticospinal Pathways of the Ankle Muscles Using Navigated Transcranial Magnetic Stimulation.

Journal Article J Vis Exp · February 19, 2019 Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans and can be assessed using transcranial magnetic stimulation (TMS). Given the role of distal leg muscl ... Full text Link to item Cite

Different Error Size During Locomotor Adaptation Affects Transfer to Overground Walking Poststroke.

Journal Article Neurorehabil Neural Repair · December 2018 BACKGROUND: Studies in neurologically intact subjects suggest that the gradual presentation of small perturbations (errors) during learning results in better transfer of a newly learned walking pattern to overground walking. Whether the same result would b ... Full text Link to item Cite

Corticospinal and intracortical excitability differ between athletes early after ACLR and matched controls.

Journal Article J Orthop Res · November 2018 Neuromuscular impairments, such as quadriceps weakness and activation deficits, persist after anterior cruciate ligament reconstruction (ACLR). Recent research demonstrating changes in the function of the primary motor cortex after ACLR posits that quadric ... Full text Link to item Cite

A locomotor learning paradigm using distorted visual feedback elicits strategic learning.

Journal Article J Neurophysiol · October 1, 2018 Distorted visual feedback (DVF) during locomotion has been suggested to result in the development of a new walking pattern in healthy individuals through implicit learning processes. Recent work in upper extremity visuomotor rotation paradigms suggest that ... Full text Link to item Cite

Characterizing the corticomotor connectivity of the bilateral ankle muscles during rest and isometric contraction in healthy adults.

Journal Article J Electromyogr Kinesiol · August 2018 The investigation of the corticomotor connectivity (CMC) to leg muscles is an emerging research area, and establishing reliability of measures is critical. This study examined the measurement reliability and the differences between bilateral soleus (SOL) a ... Full text Link to item Cite

A single exercise bout and locomotor learning after stroke: physiological, behavioural, and computational outcomes.

Journal Article J Physiol · May 15, 2018 KEY POINTS: Previous work demonstrated an effect of a single high-intensity exercise bout coupled with motor practice on the retention of a newly acquired skilled arm movement, in both neurologically intact and impaired adults. In the present study, using ... Full text Link to item Cite

The feasibility of an acute high-intensity exercise bout to promote locomotor learning after stroke.

Journal Article Top Stroke Rehabil · March 2018 BACKGROUND: People post-stroke can learn a novel locomotor task but require more practice to do so. Implementing an approach that can enhance locomotor learning may therefore improve post-stroke locomotor recovery. In healthy adults, an acute high-intensit ... Full text Link to item Cite

Motor Cortex and Motor Cortical Interhemispheric Communication in Walking After Stroke: The Roles of Transcranial Magnetic Stimulation and Animal Models in Our Current and Future Understanding.

Journal Article Neurorehabil Neural Repair · January 2016 Despite the plethora of human neurophysiological research, the bilateral involvement of the leg motor cortical areas and their interhemispheric interaction during both normal and impaired human walking is poorly understood. Using transcranial magnetic stim ... Full text Link to item Cite

Rehabilitating walking speed poststroke with treadmill-based interventions: a systematic review of randomized controlled trials.

Journal Article Neurorehabil Neural Repair · October 2013 BACKGROUND: In the past several years, several randomized controlled trials (RCTs) have been reported regarding the efficacy of treadmill-based walking-specific rehabilitation programs, either individually (TT) or combined with body weight support (BWSTT), ... Full text Link to item Cite

The influence of applying additional weight to the affected leg on gait patterns during aquatic treadmill walking in people poststroke.

Journal Article Arch Phys Med Rehabil · January 2010 UNLABELLED: Jung T, Lee D, Charalambous C, Vrongistinos K. The influence of applying additional weight to the affected leg on gait patterns during aquatic treadmill walking in people poststroke. OBJECTIVE: To investigate how the application of additional w ... Full text Link to item Cite

Modelling of power-system protective equipment on analogue computers

Journal Article Proceedings of the Institution of Electrical Engineers · 1972 Full text Cite