Accurate determination of motor evoked potential amplitude in TMS: The impact of personal and experimental factors.

Objective: Corticospinal excitability can be quantified using motor-evoked potentials (MEP) following transcranial magnetic stimulation (TMS). However, the inherent variability of MEPs poses significant challenges. We establish a framework using personal and experimental factors to select the optimal number of trials (n) required for reliable MEP estimates.

Contact heat evoked potentials reveal distinct patterns of spinal cord impairment in degenerative cervical myelopathy beyond MRI lesions.

Background: Magnetic resonance imaging may suggest spinal cord compression and structural lesions in degenerative cervical myelopathy (DCM) but cannot reveal functional impairments in spinal pathways. We aimed to assess the value of contact heat evoked potentials (CHEPs) in addition to MRI and hypothesized that abnormal CHEPs may be evident in DCM independent of MR-lesions and are related to dynamic mechanical cord stress.

Methods: Individuals with DCM underwent neurologic examination including segmental sensory (pinprick, light touch) and motor testing.

Long-term effects of concussion on attention, sensory gating and motor learning.

The current work aimed to understand the behavioral manifestations that result from disruptions to the selective facilitation of task-relevant sensory information at early cortical processing stages in those with a history of concussion. A total of 40 participants were recruited to participate in this study, with 25 in the concussion history group (Hx) and 15 in the control group (No-Hx). Somatosensory-evoked potentials (SEPs) were elicited via median nerve stimulation while subjects performed a task that manipulated their focus of attention toward or away from proprioceptive cues.

Novel Use of Motor-Evoked Potential Monitoring During Magnetic Resonance Imaging-Guided Soft-Tissue Cryoablation: A Case Report.

Motor-evoked potential (MEP) monitoring is an electrophysiologic technique useful for testing peripheral motor nerve integrity during cryoablation cases with risk of nerve injury. Previously, neuromonitoring within the magnetic resonance imaging (MRI) suite for cryoablation has not been performed as magnetic needles are used which could cause magnetic field interactions with neuromonitoring leads. We present the first report of a patient who underwent MEP monitoring during MRI-guided cryoablation of a vascular malformation adjacent to the brachial plexus.

Associative brain computer interface training increases wrist extensor corticospinal excitability in subacute stroke patients.

In a recently developed associative rehabilitative brain computer interface system, electroencephalography is used to identify the most active phase of the motor cortex during attempted movement and deliver precisely timed peripheral stimulation during training. This approach has been demonstrated to facilitate corticospinal excitability and functional recovery in patients with lower limb weakness following stroke. The current study expands those findings by investigating changes in corticospinal excitability following the associative BCI intervention in post-stroke patients with upper limb weakness.

Frequency-dependent corticospinal facilitation following tibialis anterior neuromuscular electrical stimulation.

The optimal stimulation frequency for inducing neuromodulatory effects remains unclear. The purpose of our study was to investigate the effect of neuromuscular electrical stimulation (NMES) with different frequencies on cortical and spinal excitability. Thirteen able-bodied individuals participated in the experiment involving NMES: (i) low-frequency at 25 Hz, (ii) high-frequency at 100 Hz, and (iii) mixed-frequency at 25 and 100 Hz switched every one second.

Effects of combining sensory-motor exercises with transcranial direct current stimulation on cortical processing and clinical symptoms in patients with lumbosacral radiculopathy: An exploratory randomized controlled trial.

Background: Chronic low back pain (CLBP) is linked to reduced excitability in the primary motor (M1) and sensory (S1) cortices. Combining sensory-motor exercises with transcranial direct current stimulation (tDCS) to boost M1 and S1 excitability may improve treatment outcomes. This combined approach aligns with the neurophysiological mechanisms underlying CLBP and may target the neuroplastic changes induced by low back pain.

Pharmacological blocking of spinal GABA receptors in monkeys reduces sensory transmission to the spinal cord, thalamus, and cortex.

A century of research established that GABA inhibits proprioceptive inputs presynaptically to sculpt spinal neural inputs into skilled motor output. Recent results in mice challenged this theory by showing that GABA can also facilitate action potential conduction in proprioceptive afferents. Here, we tackle this controversy in monkeys, the most human-relevant animal model, and show that GABA receptors (GABARs) indeed facilitate sensory inputs to spinal motoneurons and interneurons and that this mechanism also influences sensory transmission to supraspinal centers.

[Quantitative analysis on characteristics of electromyography and evoked potential in normal laryngeal muscles].

To quantitatively analyze and explore the characteristics, influencing factors, reference value range, and variability of electromyography and nerve evoked potential in normal laryngeal muscles. The study included 480 patients diagnosed with unilateral vocal fold immobility and underwent laryngeal electromyography (LEMG) at Beijing Tongren Hospital from June 2012 to June 2022, including 259 males and 221 females, with an average age of (44.4±14.

Generative modeling and augmentation of EEG signals using improved diffusion probabilistic models.

Objective: The development of deep learning models for electroencephalography (EEG) signal processing is often constrained by the limited availability of high-quality data. Data augmentation techniques are among the solutions to overcome these challenges, and deep neural generative models, with their data synthesis capabilities, are potential candidates.

Approach: The current work investigates enhanced diffusion probabilistic models (DPM) and sampling methods for brain signal generation and data augmentation.

Utility of narrow band imaging in a patient with a spinal cord cavernous malformation.

Background: Complete removal of the lesion from the spinal cord cavernous malformation is crucial in patients with spinal cord cavernous malformation. Herein, we report that narrow-band imaging (NBI) is useful to confirm the complete removal of spinal cord cavernous malformations.

Clinical Presentation: A 45-year-old woman was followed up for the past seven years due to multiple intracranial cavernous malformations.

Selective Muscle Involvement in Amyotrophic Lateral Sclerosis: Evidence Inferred from the Point of Motor Unit Firing Rates.

Introduction: The aim of the study is to determine the role of upper motor neuron (UMN) or lower motor neuron (LMN) dysfunction as the primary initiator of distal-proximal and lateral-medial gradients of muscle involvement in amyotrophic lateral sclerosis (ALS).

Methods: Concentric needle electromyography recordings were performed in deltoid, abductor digiti minimi, and first dorsal interosseous (FDI) muscles in patients with ALS and controls during slight voluntary contraction needed to activate two motor units (MU). Five motor unit potential (MUP) pairs were recorded from each muscle.

The Value of Intraoperative Neurophysiological Monitoring During Patient Positioning in Spine Surgery: A Preventive Strategy.

Cervical spine surgery in patients with myelopathy poses a substantial anesthetic challenge, primarily due to the risk of secondary spinal cord injury (SCI). Traditionally, concerns have centered around cervical movements during intubation. However, limited evidence supports a direct link between intubation and SCI, so anesthesiologists must consider other factors, including patient positioning, spinal perfusion pressure, and direct surgical complications.

Transesophageal motor-evoked potentials, a novel method induced by transesophageal spinal cord stimulation, are less sensitive to anesthetics than transcranial motor-evoked potentials.

Purpose: Intraoperative neurologic monitoring can be useful, but transcranial motor evoked potentials (TcMEPs) are sensitive to anesthetic agents. We compared the effects of anesthetics on the newly developed transesophageal motor evoked potentials (TeMEPs) with those on TcMEPs.

Methods: Eleven pigs (25.

TMS-evoked potential propagation reflects effective brain connectivity.

Objective Cognition is achieved through communication between brain regions. Consequently, there is considerable interest in measuring effective connectivity. A promising effective connectivity metric is transcranial magnetic stimulation (TMS) evoked potentials (TEPs), an inflection in amplitude of the electroencephalogram (EEG) recorded from one brain region as a result of TMS applied to another region.

Beta oscillation modulations of the orienting attention network effect correlate with dopamine-dependent motor symptoms of Parkinson's disease.

Attention impairment, a prevalent non-motor symptom in Parkinson's disease (PD), plays a crucial role in movement disorders. PD patients exhibit abnormalities in the attentional network related to alerting, orienting, and executive control. While dopamine medications have well-documented effects on motor function, their impact on attention networks and the underlying neural mechanisms involved in motor functions remain unclear.

Repeated epidural stimulation modulates cervical spinal cord excitability in healthy adult rats.

Spinal evoked motor responses (SEMR) are utilized in longitudinal pre-clinical and human studies to reflect the in-vivo physiological changes in neural networks secondary to a spinal cord injury (SCI) or neuro-rehabilitative treatments utilizing epidural stimulation (ES). However, it remains unknown whether the repeated ES exposure during SEMR testing itself modulates spinal cord physiology and accompanying SEMR characteristics. To answer this, ES was delivered to the cervical spinal cord using standard stimulation paradigms during multiple SEMR data acquisition sessions (~ 17 h spanning across 100 days) in ten healthy adult rats.

Superior semicircular canal dehiscence isolation by transmastoid two-point canal plugging with preservation of the vestibulo-ocular reflex.

This article describes the surgical treatment of superior semicircular canal dehiscence syndrome (SCDS) by isolating the dehiscence using transmastoid two-point canal plugging while preserving the high-frequency vestibulo-ocular reflex (VOR) of the affected semicircular canal. The superior semicircular canal is opened via a transmastoid approach anterior (as far from the ampulla as possible) and posterior to the dehiscence and then plugged with connective tissue and bone dust. In two clinical exemplary cases, vestibular testing showed that the VOR measured by video head impulse (vHIT) test was preserved (patient 1: gain preoperative 0.

Disinhibition across secondary motor cortical regions during motor sequence learning: A TMS-EEG study.

Secondary motor cortical regions, such as the supplementary motor area (SMA) are involved in planning and learning motor sequences, however the neurophysiological mechanisms across these secondary cortical networks remain poorly understood. In primary motor cortex, changes in excitatory and inhibitory neurotransmission (E:I balance) accompany motor sequence learning. In particular, there is an early reduction in inhibition (i.

Sensory Entrained TMS (seTMS) enhances motor cortex excitability.

Transcranial magnetic stimulation (TMS) applied to the motor cortex has revolutionized the study of motor physiology in humans. Despite this, TMS-evoked electrophysiological responses show significant variability, due in part to inconsistencies between TMS pulse timing and ongoing brain oscillations. Variable responses to TMS limit mechanistic insights and clinical efficacy, necessitating the development of methods to precisely coordinate the timing of TMS pulses to the phase of relevant oscillatory activity.

Modulation of anticipatory brain activity as a function of action complexity.

Stimulus-driven actions are preceded by preparatory brain activity that can be expressed by event-related potentials (ERP). Literature on this topic has focused on simple actions, such as the finger keypress, finding activity in frontal, parietal, and occipital areas detectable up to two seconds before the stimulus onset. Little is known about the preparatory brain activity when the action complexity increases, and specific brain areas designated to achieve movement integration intervene.

Longitudinal Imaging Biomarkers Correlate with Progressive Motor Deficit in the Mouse Model of Charlevoix-Saguenay Ataxia.

Objective: In autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) disease, severity and age of onset vary greatly, hindering to objectively measure and predict clinical progression. Thickening of the retinal nerve fiber layer is distinctive of ARSACS patients, as assessed by optical coherence tomography, whereas conventional brain magnetic resonance imaging findings include both supratentorial and infratentorial changes. Because longitudinal imaging studies in ARSACS patients are not available to define these changes as biomarkers of disease progression, we aimed to address this issue in the ARSACS mouse model.

Intraoperative iatrogenic seizure induced by transcranial motor-evoked potential during spinal surgery: A case report and review of the literature.

Background: Intraoperative neuromonitoring is an essential tool for detecting early intraoperative neurological changes during spinal surgery. Only rarely do seizures occur during transcranial motor-evoked potentials (TcMEP).

Case Description: A 44-year-old male presented with a magnetic resonance (MR)--documented L5-S1 T2-hyperintense intradural mass that heterogeneously enhanced with Gadolinium and extended through the right S1 neural foramen.

Continuous theta burst stimulation at 30 hz does not modulate cortical excitability in a sham-controlled study.

Theta burst stimulation (TBS) can modulate cortical excitability but suffers from high inter-subject variability. Modified TBS frequency patterns (30 Hz) showed consistent inhibitory aftereffects, but further research into the time course of these effects is needed. This study aimed to investigate the efficacy of a 30 Hz continuous TBS (cTBS) protocol.