Ratliffbengtson6598
The depotentiation protocol abolished both responses.
Non-Responder status to PAS is a state of M1 amenable to bidirectional plastic modulation when primed by a change in cerebello-thalamic drive.
The meaning of lack of responsiveness to certain protocols probing plasticity should be reconsidered.
The meaning of lack of responsiveness to certain protocols probing plasticity should be reconsidered.
The burst suppression pattern in clinical electroencephalographic (EEG) recordings is an important diagnostic tool because of its association with comas of various etiologies, as with hypoxia, drug related intoxication or deep anesthesia. The detection of bursts and the calculation of burst/suppression ratio are often used to monitor the level of anesthesia during treatment of status epilepticus. However, manual counting of bursts is a laborious process open to inter-rater variation and motivates a need for automatic detection.
We describe a novel unsupervised learning algorithm that detects bursts in EEG and generates burst-per-minute estimates for the purpose of monitoring sedation level in an intensive care unit (ICU). We validated the algorithm on 29 hours of burst annotated EEG data from 29 patients suffering from status epilepticus and hemorrhage.
We report competitive results in comparison to neural networks learned via supervised learning. The mean absolute error (SD) in bursts per minute was 0.93 (1.38).
We present a novel burst suppression detection algorithm that adapts to each patient individually, reports bursts-per-minute quickly, and does not require manual fine-tuning unlike previous approaches to burst-suppression pattern detection.
Our algorithm for automatic burst suppression quantification can greatly reduce manual oversight in depth of sedation monitoring.
Our algorithm for automatic burst suppression quantification can greatly reduce manual oversight in depth of sedation monitoring.
Communication-through-coherence proposes that the phase synchronization (PS) of neural oscillations between cortical areas supports neural communication. In this study, we exploited transcranial magnetic stimulation (TMS)-evoked potentials (TEPs) to test this hypothesis at the macroscale level, i.e., whether PS between cortical areas supports interarea communication. TEPs are electroencephalographic (EEG) responses time-locked to TMS pulses reflecting interarea communication, as they are generated by the transmission of neural activity from the stimulated area to connected regions. If interarea PS is important for communication, it should be associated with the TEP amplitude in the connected areas.
TMS was delivered over the left primary motor cortex (M1) of fourteen healthy volunteers, and 70-channel EEG was recorded. Y-27632 in vivo Early TEP components were source-localized to identify their generators, i.e., distant brain regions activated by M1 through effective connections. Next, linear regressions were used to test the relationship between the TEP amplitude and the pre-stimulus PS between the M1 and the connected regions in four frequency bands (range 4-45Hz).
Pre-stimulus interarea PS in the alpha-band was positively associated with the amplitude of early TEP components, namely, the N15 (ipsilateral supplementary motor area), P25 (contralateral M1) and P60 (ipsilateral parietal cortex).
Alpha-band PS predicts the response amplitude of the distant brain regions effectively connected to M1.
Our study supports the role of EEG-PS in interarea communication, as theorized by communication-through-coherence.
Our study supports the role of EEG-PS in interarea communication, as theorized by communication-through-coherence.
To develop and test wearable monitoring of surface electromyography and motion for detection and quantification of positive and negative myoclonus in patients with progressive myoclonic epilepsy type 1 (EPM1).
Surface electromyography and three-dimensional acceleration were measured from 23 EPM1 patients from the biceps brachii (BB) of the dominant and the extensor digitorum communis (EDC) of the non-dominant arm for 48 hours. The patients self-reported the degree of myoclonus in a diary once an hour. Severity of myoclonus with action was evaluated by using video-recorded Unified Myoclonus Rating Scale (UMRS). Correlations of monitored parameters were quantified with the UMRS scores and the self-reported degrees of myoclonus.
The monitoring-based myoclonus index correlated significantly (p<0.001) with the UMRS scores (ρ=0.883 for BB and ρ=0.823 for EDC) and with the self-reported myoclonus degrees (ρ=0.483 for BB and ρ=0.443 for EDC). Ten patients were assessed as probably having negative myoclonus in UMRS, while our algorithm detected that in twelve patients.
Wearable monitoring was able to detect both positive and negative myoclonus in EPM1 patients.
Our method is suitable for quantifying objective, real-life treatment effects at home and progression of myoclonus.
Our method is suitable for quantifying objective, real-life treatment effects at home and progression of myoclonus.
To summarize the neurophysiological properties of acute flaccid myelitis (AFM) and evaluate limb-based motor outcomes.
Nerve conduction studies (NCS) in 49 patients (21 females, 28 males; median age=52m) with AFM (median=7 d after onset; range 1-122 d) were reviewed. Neurophysiological findings, together with treatment and prognosis, and neurophysiology-neuroimaging correlations were analyzed.
The findings indicated that 64% of paralytic limbs during the acute stage (≤14 d after onset) showed diminished or absent compound muscle action potentials (CMAPs), 79% showed normal motor nerve conduction velocities, 55% showed decreased persistence or absent F-waves, and 95% showed normal sensory nerve conduction velocities. The rate of CMAP abnormalities increased from 41% on days 1-2 to 83% on days 13-14. The reduction in CMAP amplitude was correlated with weaker muscle strength at both the peak neurological deficit and the last follow-up. The baseline limb-based muscle strength at nadir and anterior horn-localized magnetic resonance imaging lesions at recovery stage (>14 d) were strong predictors of outcome at the last follow-up.
AFM typically shows neurophysiological features of neuronopathy.
NCS is probably useful in the diagnosis and evaluation of AFM.
NCS is probably useful in the diagnosis and evaluation of AFM.
The aim was to find a sensitive method to highlight the remodeling of the brain's bioelectric activity in post-stroke repair.
Fifteen mild upper limb paretic stroke patients and age-matched healthy controls were included. Repeated trials of finger tapping around the 10th and 100th days after stroke onset were recorded with a 128-channel EEG. Power spectra and Inter Trial Coherence (ITC) calculations were synchronized to tappings. ITC was correlated with motor performance.
ITC, in low frequency bands, designates the motor related bioelectric activity in channel space in both healthy subjects and patients. Ten days after stroke onset, delta-theta ITC was severely reduced compared to baseline, while three months later ITC reorganized partially over the ipsilesional central-parietal areas reflecting the improvement of motor networks. Decreased ITC in the central-parietal area remained significant compared to controls. Delta band ITC over the dorsolateral-prefrontal cortex correlates with the performance on Nine Hole Peg Test. At post-recovery, non-paretic hand tappings show significantly decreased delta-theta ITC over the supplementary motor area, which reflects network remodeling.
Inter Trial Coherence is a useful measure of brain reorganization during stroke recovery.
Delta- theta ITC is a sensitive indicator of impaired motor execution.
Delta- theta ITC is a sensitive indicator of impaired motor execution.
Port-wine birthmark (PWB) is a common occurrence in the newborn, and general pediatricians, dermatologists, and ophthalmologists are often called on to make an assessment of risk for Sturge-Weber syndrome (SWS) due to workforce shortages in pediatric neurologists and MRI's low sensitivity for SWS brain involvement in infants. We therefore aimed to develop a quantitative EEG (qEEG) approach to safely screen young infants with PWB for SWS risk and optimal timing of diagnostic MRI.
Forty-eight infants (prior to first birthday) underwent EEG recording. Signal processing methods compared voltage between left and right sides using a previously defined pipeline and diagnostic threshold. In this test sample, we compared sensitivity/specificity of the qEEG metric against MRI performed after the first birthday. We also used likelihood ratio testing to determine whether qEEG adds incremental information beyond topographical extent of PWB, another risk marker of brain involvement.
qEEG helped predict SWS risk in the first year of life (p=0.031), with a sensitivity of 50% and a specificity of 81%. It added about 40% incremental information beyond PWB extent alone (p=0.042).
qEEG adds information to risk prediction in infants with facial PWB.
qEEG can be used to help determine whether to obtain an MRI in the first year of life. The data collected can assist in developing a predictive model risk calculator that incorporates both PWB extent and qEEG results, which can be validated and then employed in the community.
qEEG can be used to help determine whether to obtain an MRI in the first year of life. The data collected can assist in developing a predictive model risk calculator that incorporates both PWB extent and qEEG results, which can be validated and then employed in the community.
The purpose of this investigation was to better understand the effects of concussions on the ability to selectively up or down-regulate incoming somatosensory information based on relevance.
Median nerve somatosensory-evoked potentials (SEPs) were elicited from electrical stimulation and recorded from scalp electrodes while participants completed tasks that altered the relevance of specific somatosensory information being conveyed along the stimulated nerve.
Within the control group, SEP amplitudes for task-relevant somatosensory information were significantly greater than for non-relevant somatosensory information at the earliest cortical processing potentials (N20-P27). Alternatively, the concussion history group showed similar SEP amplitudes for all conditions at early processing potentials, however a pattern similar to controls emerged later in the processing stream (P100) where both movement-related gating and facilitation of task-relevant information were present.
Previously concussed participants demonstrated impairments in the ability to up-regulate relevant somatosensory information at early processing stages. These effects appear to be chronic, as this pattern was observed on average several years after participants' most recent concussion.
Given the role of the prefrontal cortex in relevancy-based facilitation during movement-related gating, these findings lend support to the notion that this brain area may be particularly vulnerable to concussive forces.
Given the role of the prefrontal cortex in relevancy-based facilitation during movement-related gating, these findings lend support to the notion that this brain area may be particularly vulnerable to concussive forces.
