Effect of MEP-oriented scalp acupuncture combined with transcranial magnetic stimulation on limb motor ability in patients with ischemic stroke hemiplegia. / MEPå®šä½ä¸‹å¤´é’ˆè”åˆç»é¢ ç£åˆºæ¿€å¯¹ç¼ºè¡€æ€§è„‘å’ä¸­åç˜«æ‚£è€ è‚¢ä½“è¿åŠ¨èƒ½åŠ›çš„å½±å“.

OBJECTIVES: To observe the effect of motor evoked potential (MEP)-oriented scalp acupuncture combined with transcranial magnetic stimulation (TMS) on limb motor ability in patients with ischemic stroke hemiplegia. METHODS: A total of 60 patients with ischemic stroke hemiplegia were randomized into an observation group and a control group, 30 cases in each one. In addition to the medication treatment of internal medicine and comprehensive training of hemiplegic limbs, MEP-oriented scalp acupuncture combined with TMS was applied in the observation group, conventional scalp acupuncture at bilateral anterior oblique line of parietal and temporal regions combined with TMS was applied in the control group. The treatment was given once a day, 5 days a week for 4 weeks totally in the two groups. Before and after treatment, the scores of Fugl-Meyer assessment (FMA), modified Ashworth scale (MAS) and modified Barthel index (MBI) were observed in the two groups. RESULTS: After treatment, the FMA and MBI scores were increased compared with those before treatment in the two groups (P<0.001), and the FMA and MBI scores in the observation group were higher than those in the control group (P<0.05). After treatment, the MAS scores of upper and lower limbs in the observation group were decreased compared with those before treatment (P<0.01, P<0.001), the MAS score of lower limb in the control group was decreased compared with that before treatment (P<0.05). CONCLUSIONS: MEP-oriented scalp acupuncture combined with TMS can effectively improve the limb motor ability, daily living ability and limb spasticity in patients with ischemic stroke hemiplegia.

Thalamo-cortical evoked potentials during stimulation of the dentato-rubro-thalamic tract demonstrate synaptic filtering.

Essential tremor DBS targeting the ventral intermediate nucleus (Vim) of the thalamus and its input, the dentato-rubro-thalamic tract (DRTt), has proven to be an effective treatment strategy. We examined thalamo-cortical evoked potentials (TCEPs) and cortical dynamics during stimulation of the DRTt. We recorded TCEPs in primary motor cortex during clinical and supra-clinical stimulation of the DRTt in ten essential tremor patients. Stimulation was varied over pulse amplitude (2-10 â€‹mA) and pulse width (30-250 â€‹µs) to allow for strength-duration testing. Testing at clinical levels (3 â€‹mA, 60 â€‹µs) for stimulation frequencies of 1-160 â€‹Hz was performed and phase amplitude coupling (PAC) of beta phase and gamma power was calculated. Primary motor cortex TCEPs displayed two responses: early and all-or-none (<20 â€‹ms) or delayed and charge-dependent (>50 â€‹ms). Strength-duration curve approximation indicates that the chronaxie of the neural elements related to the TCEPs is <200 â€‹µs. At the range of clinical stimulation (amplitude 2-5 â€‹mA, pulse width 30-60 â€‹µs), TCEPs were not noted over primary motor cortex. Decreased pathophysiological phase-amplitude coupling was seen above 70 â€‹Hz stimulation without changes in power spectra and below the threshold of TCEPs. Our findings demonstrate that DRTt stimulation within normal clinical bounds does not excite fibers directly connected with primary motor cortex but that supra-clinical stimulation can excite a direct axonal tract. Both clinical efficacy and phase-amplitude coupling were frequency-dependent, favoring a synaptic filtering model as a possible mechanism of action.

Probing the Neurophysiology of Temporal Sensitivity in the Somatosensory System Using the Mismatch Negativity (MMN) Sensory Memory Paradigm.

Duration is an amodal feature common to all sensory experiences, but low-level processing of the temporal qualities of somatosensation remains poorly understood. The goal of the present study was to evaluate electrophysiological discrimination of parametric somatosensory stimuli to better understand how the brain processes the duration of tactile information. This research used a somatosensory mismatch negativity (sMMN) paradigm to evaluate electrophysiological sensitivity to differences in the duration of vibrotactile stimuli in healthy young adults. Specifically, a 100 ms standard vibration was presented 80% of the time while the remaining 20% of presentations were made up of deviant stimuli with one of the following durations: 115, 130, 145, or 160 ms. When a deviation from the anticipated tactile input is detected, the distinct electrophysiological signature of the sMMN is present. A companion behavioral task assessed individual thresholds for cognizant awareness of the standard and deviant vibrotactile stimuli. The results of the present study demonstrated a sMMN response when deviant stimuli were 130, 145, and 160 ms, but not when they were 115 ms. This suggests that on average the participants did not electrophysiologically discriminate between the 100 and 115 ms. Future work may apply this paradigm to better understand atypical tactile sensitivity in various clinical conditions.

A multi-channel EEG mini-cap can improve reliability for recording auditory brainstem responses in chinchillas.

BACKGROUND: Disabling hearing loss affects nearly 466 million people worldwide (World Health Organization). The auditory brainstem response (ABR) is the most common non-invasive clinical measure of evoked potentials, e.g., as an objective measure for universal newborn hearing screening. In research, the ABR is widely used for estimating hearing thresholds and cochlear synaptopathy in animal models of hearing loss. The ABR contains multiple waves representing neural activity across different peripheral auditory pathway stages, which arise within the first 10 ms after stimulus onset. Multi-channel (e.g., 32 or higher) caps provide robust measures for a wide variety of EEG applications for the study of human hearing. However, translational studies using preclinical animal models typically rely on only a few subdermal electrodes. NEW METHOD: We evaluated the feasibility of a 32-channel rodent EEG mini-cap for improving the reliability of ABR measures in chinchillas, a common model of human hearing. RESULTS: After confirming initial feasibility, a systematic experimental design tested five potential sources of variability inherent to the mini-cap methodology. We found each source of variance minimally affected mini-cap ABR waveform morphology, thresholds, and wave-1 amplitudes. COMPARISON WITH EXISTING METHOD: The mini-cap methodology was statistically more robust and less variable than the conventional subdermal-needle methodology, most notably when analyzing ABR thresholds. Additionally, fewer repetitions were required to produce a robust ABR response when using the mini-cap. CONCLUSIONS: These results suggest the EEG mini-cap can improve translational studies of peripheral auditory evoked responses. Future work will evaluate the potential of the mini-cap to improve the reliability of more centrally evoked (e.g., cortical) EEG responses.

Auditory cortical responses to abrupt lateralization shifts do not reflect the activity of hemifield-specific units involved in opponent coding of auditory space.

Recent studies show that the classical model based on axonal delay-lines may not explain interaural time difference (ITD) based spatial coding in humans. Instead, a population-code model called "opponent channels model" (OCM) has been suggested. This model comprises two competing channels respectively for the two auditory hemifields, each with a sigmoidal tuning curve. Event-related potentials (ERPs) to ITD-changes are used in some studies to test the predictions of this model by considering the sounds before and after the change as adaptor and probe stimuli, respectively. It is assumed in these studies that the former stimulus causes adaptation of the neurons selective to its side, and that the ERP N1-P2 response to the ITD-change is the specific response of the neurons with selectivity to the side of probe sound. However, these ERP components are known as a global, non-specific acoustic change complex of cortical origin evoked by any change in the auditory environment. It probably does not genuinely reflect the activity of some stimulus-specific neuronal units that have escaped the refractory effect of the preceding adaptor, which means a violation of the crucial assumption in an adaptor-probe paradigm. To assess this viewpoint, we conducted two experiments. In the first one, we recorded ERPs to abrupt lateralization shifts of click trains having various pre- and post-shift ITDs within the physiological range of -600µs to +600µs. Magnitudes of the ERP components P1, N1, and P2 to these ITD-shifts did not comply with the additive behavior of partial probe responses presumed for an adaptor-probe paradigm, casting doubt on the accuracy of testing sensory coding models by using ERPs to abrupt lateralization changes. Findings of the second experiment, involving ERPs to conjoint outwards/transverse shift stimuli also supported this conclusion.

Relationship between Corticospinal Excitability While Gazing at the Mirror and Motor Imagery Ability.

Mirror therapy (MT) helps stroke survivors recover motor function. Previous studies have reported that an individual's motor imagery ability is related to the areas of brain activity during motor imagery and the effectiveness of motor imagery training. However, the relationship between MT and motor imagery ability and between corticospinal tract excitability during mirror gazing, an important component of MT, and motor imagery ability is unclear. This study determined whether the motor-evoked potential (MEP) amplitude while gazing at the mirror relates to participants' motor imagery abilities. Twenty-four healthy right-handed adults (seven males) were recruited. Transcranial magnetic stimulation was performed while gazing at the mirror, and MEP of the first dorsal interosseous muscle of the right hand were measured. Motor imagery ability was measured using the Kinesthetic and Visual Imagery Questionnaire (KVIQ), which assesses the vividness of motor imagery ability. Additionally, a mental chronometry (MC) task was used to assess time aspects. The results showed a significant moderate correlation between changes in MEP amplitude values while gazing at the mirror, as compared with resting conditions, and assessment scores of KVIQ. This study shows that corticospinal excitability because of mirror gazing may be related to the vividness of motor imagery ability.

Autonomous sensory meridian response is associated with a larger heartbeat-evoked potential amplitude without differences in interoceptive awareness.

Autonomous sensory meridian response (ASMR) describes the experience of a pleasant body sensation accompanied by a feeling of well-being and relaxation in response to specific audiovisual stimuli, such as whispers and personal attention. Previous work suggests a relationship between this experience with the processing of affective and body states; however, no research has explored differences in interoception between people experiencing ASMR and those who do not. We hypothesized that the ASMR experience is based on interoception processing. To test this, we assessed group differences across different dimensions of interoception: Interoceptive sensibility (IS), measured using the multidimensional assessment of interoceptive awareness (MAIA); Interoceptive accuracy score (IAS), measured by calculating performance in a heartbeat counting task (HCT), and the electrophysiological index of interoception, the heartbeat evoked potential (HEP), which was calculated during the HCT and an ASMR tingle reporting task (ASMR-TRT). Our results showed that IS and IAS, dimensions requiring conscious awareness, showed no differences between groups. However, HEP amplitude was larger in the ASMR group in both tasks. We concluded that the ASMR experience is based on an unconscious interoceptive mechanism, reflected by HEP, where exteroceptive social-affective stimuli are integrated to represent a body state of positive affective feelings and relaxation, as has been described for affective touch. The relevance of this finding relies on that interoceptive function, body regulation, and emotional/affective experiences are fundamental for well-being, and the relationship between ASMR and interoception opens the way to future research exploring the causal relationship between them and their potential clinical applications.

Steady-state auditory motion based potentials evoked by intermittent periodic virtual sound source and the effect of auditory noise on EEG enhancement.

Hearing is one of the most important human perception forms, and humans can capture the movement of sound in complex environments. On the basis of this phenomenon, this study explored the possibility of eliciting a steady-state brain response in an intermittent periodic motion sound source. In this study, a novel discrete continuous and orderly change of sound source positions stimulation paradigm was designed based on virtual sound using head-related transfer functions (HRTFs). And then the auditory motion stimulation paradigms with different noise levels were designed by changing the signal-to-noise ratio (SNR). The characteristics of brain response and the effects of different noises on brain response were studied by analyzing electroencephalogram (EEG) signals evoked by the proposed stimulation. Experimental results showed that the proposed paradigm could elicit a novel steady-state auditory evoked potential (AEP), i.e., steady-state motion auditory evoked potential (SSMAEP). And moderate noise could enhance SSMAEP amplitude and corresponding brain connectivity. This study enriches the types of AEPs and provides insights into the mechanism of brain processing of motion sound sources and the impact of noise on brain processing.

Mechanisms of Short- and Long-Latency Sensory Suppression: Magnetoencephalography Study.

Prepulse inhibition (PPI) is sensory suppression whose mechanism (i.e., whether PPI originates from specific inhibitory mechanisms) remains unclear. In this study, we applied the combination of short-latency PPI and long-latency paired pulse suppression in 17 healthy subjects using magnetoencephalography to investigate the mechanisms of sensory suppression. Repeats of a 25-ms pure tone without a blank at 800 Hz and 70 dB were used for a total duration of 1600 ms. To elicit change-related cortical responses, the sound pressure of two consecutive tones in this series at 1300 ms was increased to 80 dB (Test). For the conditioning stimuli, the sound pressure was increased to 73 dB at 1250 ms (Pre 1) and 80 dB at 700 ms (Pre 2). Six stimuli were randomly presented as follows: (1) Test alone, (2) Pre 1 alone, (3) Pre 1 + Test, (4) Pre 2 + Test, (5) Pre 2 + Pre 1, and (6) Pre 2 + Pre 1 + Test. The inhibitory effects of the conditioning stimuli were evaluated using N100m/P200m components. The results showed that both Pre 1 and Pre 2 significantly suppressed the Test response. Moreover, the inhibitory effects of Pre 1 and Pre 2 were additive. However, when both prepulses were present, Pre 2 significantly suppressed the Pre 1 response, suggesting that the Pre 1 response amplitude was not a determining factor for the degree of suppression. These results suggested that the suppression originated from a specific inhibitory circuit independent of the excitatory pathway.

Paving the way for a better management of pain in patients with spinal cord injury: An exploratory study on the use of Functional Electric Stimulation(FES)-cycling.

CONTEXT/OBJECTIVE: Chronic pain is common in patients with spinal cord injury (SCI), for whom it negatively affects quality of life, and its treatment requires an integrated approach. To this end, lower limb functional electrical stimulation (FES) cycling holds promise. OBJECTIVE: To investigate pain reduction in a sample of patients with SCI by means of lower limb rehabilitation using FES cycling. DESIGN, SETTING AND PARTICIPANTS: Sixteen patients with incomplete and complete SCIs, attending the Neurorobotic Unit of our research institute and reporting pain at or below the level of their SCI were recruited to this exploratory study. INTERVENTIONS: Patients undertook two daily sessions of FES cycling, six times weekly, for 6 weeks. OUTCOME MEASURES: Pain outcomes were measured using the 0-10 numerical rating scale (NRS), the Multidimensional Pain Inventory for SCI (MPI-SCI), and the 36-Item Short Form Survey (SF-36). Finally, we assessed the features of dorsal laser-evoked potentials (LEPs) to objectively evaluate Aδ fiber pathways. RESULTS: All participants tolerated the intervention well, and completed the training without side effects. Statistically significant changes were found in pain-NRS, MPI-SCI, and SF-36 scores, and LEP amplitudes. Following treatment, we found that three patients experienced high pain relief (an NRS decrease of at least 80%), six individuals achieved moderate pain relief (an NRS decrease of about 30-70%), and five participants had mild pain relief (an NRS decrease of less than 30%). CONCLUSION: Our preliminary results suggest that FES cycling training is capable of reducing the pain reported by patients with SCI, regardless of American Spinal Injury Association scoring, pain level, or the neurological level of injury. The neurophysiological mechanisms underlying such effects are likely to be both spinal and supraspinal.

Attentional M100 gain modulation localizes to auditory sensory cortex and is deficient in first-episode psychosis.

Selective attention is impaired in first-episode psychosis (FEP). Selective attention effects can be detected during auditory tasks as increased sensory activity. We previously reported electroencephalography scalp-measured N100 enhancement is reduced in FEP. Here, we localized magnetoencephalography (MEG) M100 source activity within the auditory cortex, making novel use of the Human Connectome Project multimodal parcellation (HCP-MMP) to identify precise auditory cortical areas involved in attention modulation and its impairment in FEP. MEG was recorded from 27 FEP and 31 matched healthy controls (HC) while individuals either ignored frequent standard and rare oddball tones while watching a silent movie or attended tones by pressing a button to oddballs. Because M100 arises mainly in the auditory cortices, MEG activity during the M100 interval was projected to the auditory sensory cortices defined by the HCP-MMP (A1, lateral belt, and parabelt parcels). FEP had less auditory sensory cortex M100 activity in both conditions. In addition, there was a significant interaction between group and attention. HC enhanced source activity with attention, but FEP did not. These results demonstrate deficits in both sensory processing and attentional modulation of the M100 in FEP. Novel use of the HCP-MMP revealed the precise cortical areas underlying attention modulation of auditory sensory activity in healthy individuals and impairments in FEP. The sensory reduction and attention modulation impairment indicate local and systems-level pathophysiology proximal to disease onset that may be critical for etiology. Further, M100 and N100 enhancement may serve as outcome variables for targeted intervention to improve attention in early psychosis.

[Effect of electroacupuncture at back-shu points of five zang on fatigue status and cortical excitability in chronic fatigue syndrome].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at back-shu points of five zang on fatigue status, quality of life and motor cortical excitability in patients with chronic fatigue syndrome (CFS), so as to explore the possible mechanism of EA for CFS. METHODS: A total of 72 patients with CFS were randomized into an EA group (36 cases, 4 cases dropped off) and a sham EA group (36 cases, 3 cases dropped off). In the EA group, EA at Ganshu (BL 18), Xinshu (BL 15), Pishu (BL 20), Feishu (BL 13) and Shenshu (BL 23) was adopted, with continuous wave, 2 Hz in frequency. In the sham EA group, sham EA at non-acupoints (1.5-2.0 cm lateral to back-shu points of five zang) was applied, with shallow needling, and no current was connected. The treatment in the both groups was 20 min each time, once every other day, 2 weeks as one course, 3 courses were required. Before and after treatment, the scores of fatigue scale-14 (FS-14) and the MOS 36-item short form health survey (SF-36) were observed, and cortical excitability (the resting motor threshold [RMT], amplitude of motor-evoked potential [MEP-A] and latency of motor-evoked potential [MEP-L]) was detected in the two groups. RESULTS: After treatment, the physical fatigue score, mental fatigue score and total score of FS-14, as well as RMT of motor cortex in the EA group were decreased compared with those before treatment (P<0.01), the physical fatigue score and total score of FS-14 in the sham EA group were decreased compared with those before treatment (P<0.05); each item score and total score of FS-14 and RMT of motor cortex in the EA group were lower than those in the sham EA group (P<0.01, P<0.05). After treatment, each item score and total score of SF-36 and MEP-A of motor cortex in the EA group were increased compared with those before treatment (P<0.01), which were higher than those in the sham EA group (P<0.01, P<0.05). CONCLUSION: EA at back-shu points of five zang can effectively improve the fatigue status and quality of life in patients with CFS, its mechanism may be related to the up-regulating excitability of cerebral motor cortex.

[Correlation between Mandarin acceptable noise level and cortical auditory evoked potential in young normal-hearing listeners].

Objective:To investigate the correlation between Mandarin acceptable noise level （M-ANL） and cortical auditory evoked potential （CAEP）, and to explore the possible mechanism leading to individual differences in M-ANL values. Methods:Thirty listeners aged 22-33 years with normal hearing were selected as the study subjects, and the M-ANL test and CAEP test were performed respectively. The most comfortable level （MCL）, maximum background noise level （BNL）, M-ANL and CAEP values of each subject were recorded. The latency of each wave of P1, N1, P2, N2, P300 and the amplitude of P1-N1, P2-N2, P300 in CAEP were recorded for each subject. SPSS 25.0 was used for statistical analysis to explore the correlation between the MCL value, BNL value and M-ANL values and the latency of P1, N1, P2, N2, P300 and P1-N1, P2-N2, P300 amplitudes of CAEP. Results:①The MCL value and M-ANL value were positively correlated with the P2 latency of CAEP, and the correlation coefficients were 0.404 and 0.400, respectively, and the differences were statistically significant （P<0.05）. There was no correlation with P1, N1, N2, and P300 latencies of CAEP （P>0.05）. ②The MCL value, BNL value and M-ANL value had no significant difference with the CAEP wave amplitudes of P1-N1, P2-N2, and P300 （P>0.05）. Conclusion:There was a certain correlation between M-ANL and CAEP in young adults with normal hearing, suggesting that the central auditory cortex might play a potential regulatory role in the background noise tolerance. Individuals with a greater background noise acceptance might have stronger central efferent mechanisms and/or less active central afferent mechanisms.

Investigating the Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Cortical Excitability in Healthy Males.

OBJECTIVES: As a potential treatment for epilepsy, transcutaneous auricular vagus nerve stimulation (taVNS) has yielded inconsistent results. Combining transcranial magnetic stimulation with electromyography (TMS-EMG) and electroencephalography (TMS-EEG) can be used to investigate the effect of interventions on cortical excitability by evaluating changes in motor evoked potentials (MEPs) and TMS-evoked potentials (TEPs). The goal of this study is to objectively evaluate the effect of taVNS on cortical excitability with TMS-EMG and TMS-EEG. These findings are expected to provide insight in the mechanism of action and help identify more optimal stimulation paradigms. MATERIALS AND METHODS: In this prospective single-blind cross-over study, 15 healthy male subjects underwent active and sham taVNS for 60 min, using a maximum tolerated stimulation current. Single and paired pulse TMS was delivered over the right-sided motor hotspot to evaluate MEPs and TEPs before and after the intervention. MEP statistical analysis was conducted with a two-way repeated measures ANOVA. TEPs were analyzed with a cluster-based permutation analysis. Linear regression analysis was implemented to investigate an association with stimulation current. RESULTS: MEP and TEP measurements were not affected by taVNS in this study. An association was found between taVNS stimulation current and MEP outcome measures indicating a decrease in cortical excitability in participants who tolerated higher taVNS currents. A subanalysis of participants (n = 8) who tolerated a taVNS current ≥2.5 mA showed a significant increase in the resting motor threshold, decrease in MEP amplitude and modulation of the P60 and P180 TEP components. CONCLUSIONS: taVNS did not affect cortical excitability measurements in the overall population in this study. However, taVNS has the potential to modulate specific markers of cortical excitability in participants who tolerate higher stimulation levels. These findings indicate the need for adequate stimulation protocols based on the recording of objective outcome parameters.

[Effects of eye acupuncture on motor evoked potential and somatosensory evoked potential in patients with incomplete spinal cord injury based on neuroelectrophysiological technology].

OBJECTIVE: To observe the effects of eye acupuncture on motor evoked potential (MEP) and somatosensory evoked potential (SEP) in the patients with incomplete spinal cord injury so as to evaluate its clinical efficacy. METHODS: According to the random number table, 90 patients were divided into exercise therapy group, eye acupuncture group and eye acupuncture combined exercise therapy group (combined treatment group), 30 cases in each. In the exercise therapy group, patients were treated with the routine exercise and occupational therapy. Patients of the eye acupuncture group were treated with eye acupuncture at upper jiao region, lower jiao region, liver region and kidney region bilaterally. Patients of the combined treatment group were given the routine exercise and occupational therapy combined with eye acupuncture. All the treatments were conducted once daily, 7 days as one treatment course for 4 treatment courses. Before treatment and 4 weeks after treatment, the motor function, light touch sensation and pinprick sensation, injury grade and clinical efficacy were assessed separately, using the criteria developed by the American Spinal Injury Association. The modified Barthel index(MBI) was adopted to evaluate the activities of daily livings. By monitoring SEP and MEP, the neurophysiological conditions were assessed for spinal cord injury. RESULTS: The total effective rate was 56.7% (17/30), 66.7% (20/30) and 90.0% (27/30) in the exercise therapy group, the eye acupuncture group and the combined treatment group, respectively. The total effective rate in the combined treatment group was higher than those in the other two groups (P<0.05). Compared with those before treatment, the scores of motor function, light tough sensation and pinprick sensation were all increased after treatment in three groups (P<0.05), MBI score was increased in both the exercise therapy group and the combined treatment group (P<0.05), and the latency of SEP (N11, N20, N23, P38) and the Cortical (hand region), Csp, Cortical (leg region) and Lsp of MEP were all shortened in the three groups separately (P<0.05). After treatment, compared with the exercise therapy group, the score of motor function was increased (P<0.05), MBI score decreased (P<0.05) and MEP latency shortened (P<0.05) in the eye acupuncture group. After treatment, compared with the exercise therapy group and the eye acupuncture group, the scores of motor function, light touch sensation and pinprick sensation, as well as MBI score were all increased (P<0.05), and the latency of SEP (N11,N20,N23,P38) and MEP shortened (P<0.05) in the combined treatment group. CONCLUSION: In treatment of incomplete spinal cord injury, eye acupuncture combined with exercise therapy can significantly increase the excitability of sensory and motor nerve conduction in the spinal cord and cerebral cortex of patients, effectively promote the recovery of patients' motor and sensory function and improve the activities of daily living.

Imagined paralysis reduces motor cortex excitability.

Mental imagery is a powerful capability that engages similar neurophysiological processes that underlie real sensory and motor experiences. Previous studies show that motor cortical excitability can increase during mental imagery of actions. In this study, we focused on possible inhibitory effects of mental imagery on motor functions. We assessed whether imagined arm paralysis modulates motor cortical excitability in healthy participants, as measured by motor evoked potentials (MEPs) of the hand induced by near-threshold transcranial magnetic stimulation (TMS) over the primary motor cortex hand area. We found lower MEP amplitudes during imagined arm paralysis when compared to imagined leg paralysis or baseline stimulation without paralysis imagery. These results show that purely imagined bodily constraints can selectively inhibit basic motor corticospinal functions. The results are discussed in the context of motoric embodiment/disembodiment.

Effect of Electro-Acupuncture on Lateralization of the Human Swallowing Motor Cortex Excitability by Navigation-Transcranial Magnetic Stimulation-Electromyography.

Background: The use of transcranial magnetic stimulation combined with electromyography for the functional evaluation of the cerebral cortex in both clinical and non-clinical populations is becoming increasingly common. Numerous studies have shown that electro-acupuncture (EA) can regulate cerebral cortical excitability. However, the effect of EA on the lateralization of the human swallowing motor cortex excitability is not yet fully understood. Objective: The aim of this study was to assess whether lateralization is present in the swallowing motor cortex of healthy subjects, and to investigate the impact of EA at Lianquan (CV23) and Fengfu (GV16) on lateralization. Methods: Forty subjects were randomized 1:1 into the EA group and the sham-EA group. The bilateral swallowing motor cortices was located by a neuroimaging navigation system. Then, the resting motor threshold (RMT) and motor evoked potential (MEP) of the mylohyoid of healthy subjects were recorded while applying combined transcranial magnetic stimulation and electromyography before and after EA or sham-EA. Results: First, the RMT and MEP latency of the contralateral mylohyoid innervated by the right swallowing cortex (71.50 ± 1.67%, 8.30 ± 0.06 ms) were lower than those innervated by the left (79.38 ± 1.27%, 8.40 ± 0.06 ms). Second, EA at CV23 and GV16 reduced the bilateral RMT and enhanced the bilateral MEP latency and amplitude (P = 0.005, P < 0.001; P = 0.002, P = 0.001; P = 0.002, P = 0.009), while sham-EA did not (P > 0.05). Third, EA had an effect on the RMT and MEP latency in terms of lateralization changes, but this was not significant (P = 0.067, P = 0.156). Conclusion: The right swallowing motor cortex of healthy subjects is more excitable than that of the left at resting state. Thus, we found that lateralization is present in the swallowing motor cortex of healthy people, which might indicate a hemispheric dominance of swallowing predominates in the right swallowing motor cortex. In addition, EA at CV23 and GV16 can instantly promote the excitability of the bilateral swallowing motor cortices. But there was no significant difference in EA stimulation in terms of lateralization.

Auricular transcutaneous vagus nerve stimulation modulates the heart-evoked potential.

BACKGROUND: There is active interest in biomarker discovery for transcutaneous auricular vagus nerve stimulation (taVNS). However, greater understanding of the neurobiological mechanisms is needed to identify candidate markers. Accumulating evidence suggests that taVNS influences activity in solitary and parabrachial nuclei, the primary brainstem relays for the transmission of visceral sensory afferents to the insula. The insula mediates interoception, which concerns the representation and regulation of homeostatic bodily states. Consequently, interoceptive pathways may be relevant to taVNS mechanisms of action. HYPOTHESES: We hypothesized that taVNS would modulate an EEG-derived marker of interoceptive processing known as the heart-evoked potential (HEP). We also hypothesized that taVNS-induced HEP effects would be localizable to the insula. METHODS: Using a within-subject, sham-controlled design, we recorded EEG and ECG concurrent to taVNS in 43 healthy adults. Using ECG and EEG data, we extracted HEPs. Estimation of the cortical sources of the taVNS-dependent HEP responses observed at the scalp were computed using the Boundary Element Method and weighted Minimum Norm Estimation. Statistics were calculated using cluster-based permutation methods. RESULTS: taVNS altered HEP amplitudes at frontocentral and centroparietal electrode sites at various latencies. The taVNS-dependent HEP effect was localized to the insula, operculum, somatosensory cortex, and orbital and ventromedial prefrontal regions. CONCLUSION: The results support the hypothesis that taVNS can access the insula as well as functionally and anatomically connected brain regions. HEPs may serve as an objective, non-invasive outcome parameter for the cortical effects of taVNS.

Traumatic Optic Neuropathy (TON) and Ayurveda - A case report.

The vision loss in the Traumatic Optic Neuropathy is the impact of deformational forces. This occurs due to direct or indirect injuries during trauma to skull. The use of high dose corticosteroids is the primary line of treatment in such injuries still remains a matter of debate. Traumatic Optic Neuropathy is yet an unexplored topic of study in Ayurveda. The Traumatic Optic Neuropathy can be correlated with Abhighatajanya Vataprakopaj Drishtinash. The treatment principles of Vataprakopaj Vyadhi are Snehan (massage), Swedan (sudation), Basti (enema) and Nasya (oleation through nasal route). A 50 year old male patient came to outpatient department suffered from motorcycle accident and had a forehead trauma followed by loss of vision in both eyes after 5 days and diagnosed as Traumatic Optic Neuropathy. An electrophysiological assessment showed absence of waveform in Visual Evoked Potential (VEP). According to Ayurveda patient was diagnosed primarily as Abhighatajanya Vataprakopaj Drishtinash and started to follow the protocol of Vataprakopaj Vyadhi. Patient received Ayurvedic formulations in morning, after meal and at night for 12 months and a course of Yapan Basti (medicated decoction enema) followed by Netratarpan (eye satiation), Nasya and Abhyanga (body and foot massage). Patient showed an improvement in the visual quality from no perception of light to perception of light and rays in right eye in 9 month. Patient had improvement in P100 latencies of right eye in VEP report and subjective improvement in quality of vision to perceive the images and objects. Application of Ayurvedic principles and Panchakarma therapy resulted in improvement of the case. An early management of Traumatic Optic Neuropathy with Ayurvedic treatment can have a significant impact on the clinical/visual outcome in terms of recovery in damaged optic nerve fibers.

Comparative sound detection abilities of four decapod crustaceans.

Sound perception and detection in decapod crustaceans is surprisingly poorly understood, even though there is mounting evidence for sound playing a critical role in many life history strategies. The suspected primary organ of sound perception is the paired statocysts at the base of the first antennal segment. To better understand the comparative sound detection of decapods, auditory evoked potentials were recorded from the statocyst nerve region of four species (Leptograpsus variegate, Plagusia chabrus, Ovalipes catharus, Austrohelice crassa) in response to two different auditory stimuli presentation methods, shaker table (particle acceleration) and underwater speaker (particle acceleration and pressure). The results showed that there was significant variation in the sound detection abilities between all four species. However, exposure to the speaker stimuli increased all four species sound detection abilities, in terms of both frequency bandwidth and sensitivity, compared with shaker table-derived sound detection abilities. This indicates that there is another sensory mechanism in play as well as the statocyst system. Overall, the present research provides comparative evidence of sound detection in decapods and indicates underwater sound detection in this animal group was even more complex than previously thought.