Changes In Latency Research Articles

Trajectories of sleep problems from adolescence to adulthood. Linking two population-based studies from Norway

Study objectiveThe aim of the study is to assess stability and predictors of insomnia and sleep duration from adolescence to early adulthood. MethodsA longitudinal sample of 1257 individuals from three age cohorts were assessed from linked population-based studies, the youth@hordaland study from 2012 (age 16–18) and the SHoT2018 study (age 22–25). Identical measures of insomnia symptoms and sleep duration were analysed. ResultsThe stability of insomnia was high from adolescence to young adulthood, 50% of those with insomnia symptoms in adolescence still had insomnia symptoms six years later (adjusted IRR = 2.01; (CI 95%; 1.5–2.44)). Short sleep duration was also stable, with 67.8% of the adolescents in the lowest sleep duration quartile still remaining in the lowest quartile six years later. The overall rate of insomnia symptoms, long wake after sleep onset (WASO), and oversleeping increased from adolescence to young adulthood. Also, we observed a reduction in sleep efficiency and later rise times. There was no significant change in sleep onset latency (SOL). ConclusionInsomnia symptoms and short sleep duration are prevalent during both adolescence and young adulthood. Considerable individual stability and a rising rate of insomnia symptoms were observed over time. These findings underscore the importance of early identification and timely interventions to prevent chronic sleep problems.

Ocular and cervical vestibular evoked myogenic potentials elicited by air-conducted, low-frequency sound.

Sound is not only detected by the cochlea, but also, at high intensities, by the vestibular system. Acoustic activation of the vestibular system can manifest itself in vestibular evoked myogenic potentials (VEMPs). In a clinical setting, VEMPs are usually evoked with rather high-frequency sound (500 Hz and higher), despite the fact that only a fraction of saccular and utricular hair cells in the striolar region is available for high-frequency stimulation. As a growing proportion of the population complains about low-frequency environmental noise, including reports on vestibular symptoms, the activation of the vestibular system by low-frequency sound deserves better understanding. We recorded growth functions of oVEMPs and cVEMPs evoked with air-conducted sound at 120 Hz and below. We estimated VEMP thresholds and tested whether phase changes of the stimulus carrier result in changes of VEMP amplitude and latency. The VEMP response of the otholith organs to low-frequency sound is uniform and not tuned when corrected for middle ear attenuation by A-weighting the stimulus level. Different stimulus carrier phases result in phase-correlated changes of cVEMP latencies and amplitudes. VEMPs can be evoked with rather low-frequency sound, but high thresholds suggest that they are unlikely to be triggered by environmental sounds.

The efficacy of ball blankets on insomnia in depression in outpatient clinics: study protocol for a randomized crossover multicentre trial

BackgroundDepression affects approx. 4% of the global population and is often accompanied by insomnia. Medications used to treat insomnia can have side effects such as development of tolerance and addiction. The Protac Ball Blanket™ (PBB) is a non-pharmacological supplement to sedatives and hypnotics, but evidence for the efficacy of PBB is needed before the treatment is implemented. The objective of this trial is to test the efficacy of PBB on insomnia caused by depression in a randomized controlled design.MethodsThis study is a multicentre, randomized crossover trial with planned inclusion of 45 patients. The randomization procedure is permuted-block randomization with varying block sizes. Patients are allocated into either a sequence “AB” or “BA” each lasting 4 weeks (28 nights). Patients randomized to the “AB” sequence receive treatment A (Protac Ball Blanket™) in the first 2 weeks and switch to treatment B (treatment as usual) in the second period, whereas patients who are randomized to the BA sequence receive treatment B in the first period and treatment A in the second period. The participants will serve as their own control in this design. The primary outcome is changes in total sleep time. Secondary outcome measures are changes in sleep onset latency, number of awakenings, wake after sleep onset, and use of sedatives and hypnotics. Furthermore, quality of sleep, insomnia severity status, and self-reported symptoms of depression, anxiety, interpersonal sensitivity, and neurasthenia will be measured. A paired, two-sided t test to compare the means of the differences in the outcomes will be performed.DiscussionThis clinical trial will assess the effect of PBB on depression-related insomnia. The outcomes are of high interest as the PBB is a potential non-pharmacological supplement to medical treatment of patients with insomnia due to depression.Trial registrationClinicalTrials.gov Identifier: NCT03730974. Registered on 5 November 2018.

Feasibility of Using Intraoperative Neuromonitoring in the Prophylaxis of Dysesthesia in Transforaminal Endoscopic Discectomies of the Lumbar Spine.

(1) Background: Postoperative nerve root injury with dysesthesia is the most frequent sequela following lumbar endoscopic transforaminal discectomy. At times, it may be accompanied by transient and rarely by permanent motor weakness. The authors hypothesized that direct compression of the exiting nerve root and its dorsal root ganglion (DRG) by manipulating the working cannula or endoscopic instruments may play a role. (2) Objective: To assess whether intraoperative neurophysiological monitoring can help prevent nerve root injury by identifying neurophysiological events during the initial placement of the endoscopic working cannula and the directly visualized video endoscopic procedure. (3) Methods: The authors performed a retrospective chart review of 65 (35 female and 30 male) patients who underwent transforaminal endoscopic decompression for failed non-operative treatment of lumbar disc herniation from 2012 to 2020. The patients’ age ranged from 22 to 86 years, with an average of 51.75 years. Patients in the experimental group (32 patients) had intraoperative neurophysiological monitoring recordings using sensory evoked (SSEP), and transcranial motor evoked potentials (TCEP), those in the control group (32 patients) did not. The SSEP and TCMEP data were analyzed and correlated to the postoperative course, including dysesthesia and clinical outcomes using modified Macnab criteria, Oswestry disability index (ODI), visual analog scale (VAS) for leg and back pain. (4) Results: The surgical levels were L4/L5 in 44.6%, L5/S1 in 23.1%, and L3/L4 in 9.2%. Of the 65 patients, 56.9% (37/65) had surgery on the left, 36.9% (24/65) on the right, and the remaining 6.2% (4/65) underwent bilateral decompression. Postoperative dysesthesia occurred in 2 patients in the experimental and six patients in the control group. In the experimental neuromonitoring group, there was electrodiagnostic evidence of compression of the exiting nerve root’s DRG in 24 (72.7%) of the 32 patients after initial transforaminal placement of the working cannula. A 5% or more decrease and a 50% or more decrease in amplitude of SSEPs and TCEPs recordings of the exiting nerve root were resolved by repositioning the working cannula or by pausing the root manipulation until recovery to baseline, which typically occurred within an average of 1.15 min. In 15 of the 24 patients with such latency and amplitude changes, a foraminoplasty was performed before advancing the endoscopic working cannula via the transforaminal approach into the neuroforamen to avoid an impeding nerve root injury and postoperative dysesthesia. (5) Conclusion: Neuromonitoring enabled the intraoperative diagnosis of DRG compression during the initial transforaminal placement of the endoscopic working cannula. Future studies with more statistical power will have to investigate whether employing neuromonitoring to avoid intraoperative compression of the exiting nerve root is predictive of lower postoperative dysesthesia rates in patients undergoing videoendoscopic transforaminal discectomy.

5-HT7 receptors increase the excitability of hippocampal CA1 pyramidal neurons by inhibiting the A-type potassium current

Accumulating evidence suggests a widespread role of serotonin 5-HT7 receptors (5-HT7Rs) in the physiology of cognitive and affective processing. However, we still lack insights into 5-HT7R electrophysiology. Studies analyzing the 5-HT7R-mediated changes in CA1 pyramidal neuron activity revealed that 5-HT7R activation leads to the opening of hyperpolarization-activated cyclic nucleotide-gated cation channels (HCNs). However, our group and others have shown that CA1 pyramidal cells increase their excitability following 5-HT7R activation, an effect which cannot be explained by HCN channel opening. This suggests a different ionic mechanism might be responsible. To investigate this, we performed whole-cell patch clamp recordings of CA1 pyramidal cells in rat brain slices. It was found that acute 5-HT7R activation increased membrane excitability and decreased spiking latency. Both effects were blocked by a selective 5-HT7R antagonist. Spike latency in CA1 pyramidal cells is known to be regulated by transient outward voltage-dependent A-type potassium channels. Subsequent voltage clamp recordings revealed that acute 5-HT7R activation inhibited A-type potassium currents. Pharmacological block of Kv4.2/4.3 potassium channel subunits prevented the 5-HT7R agonist-induced changes in excitability and spiking latency, whereas blocking HCN channels had no influence on these effects. Taken together, the results reveal an ionic mechanism previously not known to be associated with 5-HT7R activation. Inhibition of A-type potassium channels can fully account for increased CA1 pyramidal cell excitability after 5-HT7R activation. These results can help explain a number of behavioral and physiological findings and will hopefully lead to a better understanding of 5-HT7 receptor signaling in health and disease.

The Effect of Increasing Interphase Gap on N1 Latency of the Electrically Evoked Compound Action Potential and the Stimulation Level Offset in Human Cochlear Implant Users.

This study reports two potential biomarkers of the physiological status of the cochlear nerve (CN) in cochlear implant users. This project represents a complementary analysis on a subset of electrophysiological data from our recently published study. This study compared changes in N1 latency and stimulation level (i.e., N1 latency offset and stimulation level offset) with increasing interphase gap of a biphasic pulse between children with cochlear nerve deficiency and children with normal-sized CNs. Children with cochlear nerve deficiency showed smaller N1 latency offsets and larger stimulation level offsets than children with normal-sized CNs at all electrode locations tested. The N1 latency and stimulation level offsets differ in two patient populations with different physiological statuses of the CN. These parameters may be useful for evaluating CN function in individual cochlear implant patients.

Age-Related Changes in Auditory Nogo-N200 Latency in Medication-Naïve Children and Adolescents with Attention-Deficit/Hyperactivity Disorder.

Objective Event-related potential (ERP) changes with brain development in healthy children and adolescents. However, few studies have focused on age-related changes in the N200 and P300 components among individuals with attention-deficit/hyperactivity disorder (ADHD). Therefore, this study aimed to assess age-related differences in the auditory nogo-N200 components in individuals with ADHD. Methods We enrolled 46 participants with auditory nogo-N200 and nogo-P300 components. We assessed ADHD symptoms using the Advanced Test of Attention (ATA) and Korean ADHD Rating Scale-IV (K-ARS-IV). Moreover, we assessed emotional and behavioral problems using the Korean Child Behavior Checklist (K-CBCL). Further, we measured auditory ERPs. Results There were no differences with respect to sex or ATA, K-ARS-IV, and K-CBCL scores between the groups. With a 1-year increase in age, the nogo-N200 latency at Fz and Cz decreased by 6.08 ms and 4.88 ms, respectively; this result was statistically significant in multivariable linear regression adjusted by sex and dominant hand. Conclusion Our findings revealed age-related changes in nogo-N200 latency at the Fz and Cz electrodes in individuals with ADHD. Future studies should perform comparisons with healthy controls to determine whether auditory nogo-N200 can be used to evaluate the developmental level in individuals with ADHD.

Early disability in ambulatory patients with multiple sclerosis: optical coherence tomography versus visual evoked potentials, a comparative study

BackgroundMultiple sclerosis (MS) is a common cause of neurological disabilities in adults and commonly affects the visual pathway. The objective of this study is to assess and compare the sensitivity of visual evoked potentials (VEP) and optical coherence tomography (OCT) as measures of early disability in ambulatory patients with MS.MethodsForty-four patients with MS with Expanded Disability Status Scale (EDSS) of ≤ 4.5 (ambulatory patients) and 14 healthy controls participated in this study. Patients were classified into 3 groups according to EDSS. Patients with EDSS of 0–1.5 formed the “No disability,” patients with EDSS of 2–3 formed the “Minimal to mild disability,” and finally patients with EDSS of 3.5–4.5 formed the “Moderate to significant disability” groups. N75/P100 amplitude, P100 latency, retinal nerve fiber layer (RNFL) thickness, and ganglion cell layer complex (GCLC) thickness were measured.ResultsPatients showed significantly lower N75/P100 amplitude, higher P100 latency, lower RNFL, and GCLC thicknesses compared to controls. However, there were non-significant changes in P100 latency, N75/P100 amplitude, and GCLC thickness among the 3 groups for both patients with and without history of optic neuritis (ON). On contrary, RNFL thickness was significantly different between the three groups for both patients with and without history of ON. Factorial ANOVA revealed non-significant disability × History of ON interaction.ConclusionCompared to VEP parameters, RNFL thickness was a sensitive correlate with the various degrees of early disability in fully ambulatory patients with MS whatever the history of ON.

Changes in P1 latencies of children with normal hearing and those with cochlear implants

Background/aimThe aim of this study was to determine the age-related latency interval of P1 latencies of children with normal hearing, and to evaluate the P1 latency changes after surgery in children who underwent cochlear implantation.Materials and methods We evaluated 60 children with normal hearing and 16 children with cochlear implants aged 0–6 years using cortical auditory evoked potentials. P1 latencies were measured only once in the children with normal hearing, and on the postoperative first day, and the first, third, and sixth postoperative months in the children with cochlear implants.ResultsThere was a statistically significant decrease in the P1 latencies as the age increased in children with normal hearing (P < 0.001). It was determined that when the external partof the cochlear implant was applied, the P1 latencies of children with cochlear implants were significantly longer than those of age-matched children with normal hearing (P < 0.001). This difference disappeared in 10 children with implants at the third and sixth months, but significant differences remained in 6 children.ConclusionP1 latency could be used as an objective tool to evaluate the normal development of auditory pathways, and may be helpful in the effective programming of children undergoing cochlear implantation.

P300 cognitive assessment in patients with first-episode psychosis: a prospective case-control study

BackgroundSeveral studies using event-related potential (ERP) methods have reported a relationship between the cognitive dysfunction of patients with psychosis and P300 latency and amplitude. P300 follow-up studies in patients with schizophrenia receiving antipsychotic treatment revealed that the P300 amplitudes were increased while other studies showed limited changes in the P300 amplitude even after antipsychotics use.ResultsWe found that at the first presentation, all patients’ groups have significantly lower amplitude and more prolonged latency of P300 than controls. All the first-episode psychosis patients showed a significant improvement of P300 amplitude mean scores after 1 year, but with no significant change in the P300 latency. There was an inverse correlation between the patients’ PANSS scores and their P300 latency and amplitude values.ConclusionP300 amplitude and latency might be of clinical value in the evaluation of cognitive functions in the first-episode psychosis patients. The abnormalities in P300 may be improved with continuous control of psychotic symptoms with psychotropic medications.

Optimizing Auditory Brainstem Response Acquisition Using Interleaved Frequencies.

Auditory brainstem responses (ABRs) require averaging responses to hundreds or thousands of repetitions of a stimulus (e.g., tone pip) to obtain a measurable evoked response at the scalp. Fast repetition rates lead to changes in ABR amplitude and latency due to adaptation. To minimize the effect of adaptation, stimulus rates are sometimes as low as 10 to 13.3 stimuli per second, requiring long acquisition times. The trade-off between reducing acquisition time and minimizing the effect of adaptation on ABRs is an especially important consideration for studies of cochlear synaptopathy, which use the amplitude of short latency responses (wave 1) to assess auditory nerve survival. It has been proposed that adaptation during ABR acquisition can be reduced by interleaving tones at different frequencies, rather than testing each frequency serially. With careful ordering of frequencies and levels in the stimulus train, adaptation in the auditory nerve can be minimized, thereby permitting an increase in the rate at which tone bursts are presented. However, widespread adoption of this stimulus design has been hindered by lack of available software. Here, we develop and validate an interleaved stimulus design to optimize the rate of ABR measurement while minimizing adaptation. We implement this method in an open-source data acquisition software tool that permits either serial or interleaved ABR measurements. The open-source software library, psiexperiment, is compatible with widely used ABR hardware. Consistent with previous studies, careful design of an interleaved stimulus train can reduce ABR acquisition time by more than half, with minimal effect on ABR thresholds and wave 1 latency, while improving measures of wave 1 amplitude.

Cognitive behavioural therapy for insomnia in patients with rheumatoid arthritis: protocol for the randomised, single-blinded, parallel-group Sleep-RA trial

BackgroundMore than half of patients with rheumatoid arthritis complain of insomnia, which is predominantly treated with hypnotic drugs. However, cognitive behavioural therapy for insomnia is recommended as the first-line treatment in international guidelines on sleep. Patients with rheumatoid arthritis suffer from debilitating symptoms, such as fatigue and pain, which can also be linked to sleep disturbance. It remains to be determined whether cognitive behavioural therapy for insomnia can be effective in patients with rheumatoid arthritis. The aim of the Sleep-RA trial is to investigate the efficacy of cognitive behavioural therapy for insomnia on sleep and disease-related symptoms in patients with rheumatoid arthritis. The primary objective is to compare the effect of cognitive behavioural therapy for insomnia relative to usual care on changes in sleep efficiency from baseline to week 7 in patients with rheumatoid arthritis. The key secondary objectives are to compare the effect of cognitive behavioural therapy for insomnia relative to usual care on changes in sleep onset latency, wake after sleep onset, total sleep time, insomnia, sleep quality, fatigue, impact of rheumatoid arthritis and depressive symptoms from baseline to week 26 in patients with rheumatoid arthritis.MethodsThe Sleep-RA trial is a randomised controlled trial with a two-group parallel design. Sixty patients with rheumatoid arthritis, insomnia and low-to-moderate disease activity will be allocated 1:1 to treatment with cognitive behavioural therapy for insomnia or usual care. Patients in the intervention group will receive nurse-led, group-based cognitive behavioural therapy for insomnia once a week for 6 weeks. Outcome assessments will be carried out at baseline, after treatment (week 7) and at follow-up (week 26).DiscussionData on treatment of insomnia in patients with rheumatoid arthritis are sparse. The Sleep-RA trial is the first randomised controlled trial to investigate the efficacy of cognitive behavioural therapy for insomnia in patients with rheumatoid arthritis. Because symptoms of rheumatoid arthritis and insomnia have many similarities, we also find it relevant to investigate the secondary effects of cognitive behavioural therapy for insomnia on fatigue, impact of rheumatoid arthritis, depressive symptoms, pain, functional status, health-related quality of life and disease activity.If we find cognitive behavioural therapy for insomnia to be effective in patients with rheumatoid arthritis this will add weight to the argument that evidence-based non-pharmacological treatment for insomnia in rheumatological outpatient clinics is eligible in accordance with the existing international guidelines on sleep.Trial registrationClinicalTrials.gov: NCT03766100. Registered on 30 November 2018.

Physical Salience and Value-Driven Salience Operate through Different Neural Mechanisms to Enhance Attentional Selection.

Previous studies have indicated that both increased physical salience and increased reward-value salience of a target improve behavioral measures of attentional selection. It is unclear, however, whether these two forms of salience interact with attentional networks through similar or different neural mechanisms, and what such differences might be. We examined this question by separately manipulating both the value-driven and physical salience of targets in a visual search task while recording response times (RTs) and event-related potentials, focusing on the attentional-orienting-sensitive N2pc event-related potential component. Human participants of both sexes searched arrays for targets of either a high-physical-salience color or one of two low-physical-salience colors across three experimental phases. The first phase ("baseline") offered no rewards. RT and N2pc latencies were shorter for high-physical-salience targets, indicating faster attentional orienting. In the second phase ("equal-reward"), a low monetary reward was given for fast correct responses for all target types. This reward context improved overall performance, similarly shortening RTs and enhancing N2pc amplitudes for all target types, but with no change in N2pc latencies. In the third phase ("selective-reward"), the reward rate was made selectively higher for one of the two low-physical-salience colors, resulting in their RTs becoming as fast as the high-physical-salience targets. Despite the equally fast RTs, the N2pc's for these low-physical-salience, high-value targets remained later than for high-physical-salience targets, instead eliciting significantly larger N2pc's. These results suggest that enhanced physical salience leads to faster attentional orienting, but value-driven salience to stronger attentional orienting, underscoring the utilization of different underlying mechanisms.SIGNIFICANCE STATEMENT Associating relevant target stimuli with reward value can enhance their salience, facilitating their attentional selection. This value-driven salience improves behavioral performance, similar to the effects of physical salience. Recent theories, however, suggest that these forms of salience are intrinsically different, although the neural mechanisms underlying any such differences remain unclear. This study addressed this issue by manipulating the physical and value-related salience of targets in a visual search task, comparing their effects on several attention-sensitive neural-activity measures. Our findings show that, whereas physical salience accelerates the speed of attentional selection, value-driven salience selectively enhances its strength. These findings shed new insights into the theoretical and neural underpinnings of value-driven salience and its effects on attention and behavior.

Primate Amygdalo-Nigral Pathway for Boosting Oculomotor Action in Motivating Situations.

SummaryA primary function of the primate amygdala is to modulate behavior based on emotional cues. To study the underlying neural mechanism, we first inactivated the amygdala locally and temporarily by injecting a GABA agonist. Then, saccadic eye movements and gaze were suppressed only on the contralateral side. Next, we performed optogenetic activation after injecting a viral vector into the amygdala. Optical stimulation in the amygdala excited amygdala neurons, whereas optical stimulation of axon terminals in the substantia nigra pars reticulata inhibited nigra neurons. Optical stimulation in either structure facilitated saccades to the contralateral side. These data suggest that the amygdala controls saccades and gaze through the basal ganglia output to the superior colliculus. Importantly, this amygdala-derived circuit mediates emotional context information, whereas the internal basal ganglia circuit mediates object value information. This finding demonstrates a basic mechanism whereby basal ganglia output can be modulated by other areas conveying distinct information.

Path persistence in the cloud

A commonly held belief is that traffic engineering and routing changes are infrequent. However, based on our measurements over a number of years of traffic between data centers in one of the largest cloud provider's networks, we found that it is common for flows to change paths at ten-second intervals or even faster. These frequent path and, consequently, latency variations can negatively impact the performance of cloud applications, specifically, latency-sensitive and geo-distributed applications. Our recent measurements and analysis focused on observing path changes and latency variations between different Amazon aws regions. To this end, we devised a path change detector that we validated using both ad hoc experiments and feedback from cloud networking experts. The results provide three main insights: (1) Traffic Engineering (TE) frequently moves (TCP and UDP) flows among network paths of different latency, (2) Flows experience unfair performance, where a subset of flows between two machines can suffer large latency penalties (up to 32% at the 95th percentile) or excessive number of latency changes, and (3) Tenants may have incentives to selfishly move traffic to low latency classes (to boost the performance of their applications). We showcase this third insight with an example using rsync synchronization. To the best of our knowledge, this is the first paper to reveal the high frequency of TE activity within a large cloud provider's network. Based on these observations, we expect our paper to spur discussions and future research on how cloud providers and their tenants can ultimately reconcile their independent and possibly conflicting objectives. Our data is publicly available for reproducibility and further analysis at http://goo.gl/25BKte.

Effect of miR-124 on PI3K/Akt signal pathway in refractory epilepsy rats

This research aimed to investigate the effect of miR-124 on the PI3K/Akt signaling pathway in refractory epilepsy rats. Ten healthy SD rats were selected as a control group, thirty-six successfully established model rats were randomly divided into the model group, mir-124-agomir, mir-124-antagomir, mir-124-agomir+ LY294002 group (combined group), with 9 rats in each group. PI3K or (and) Akt expressions were intervened respectively. The changes in attack latency and cognitive function were observed, and the correlation among miR-124, PI3K, Akt, and attack latency was analyzed. Up-regulation of the level of miR-124 could increase the seizure interval of rats (P&lt; 0.05), improve the cognitive function of rats (P&lt; 0.05), and promote the expression of PI3K, AKT. The level of miR-124, PI3K, Akt was positively correlated with the latent time of seizures in rats, and the level of miR-124 was positively correlated with the level of PI3K, Akt (P&lt; 0.05). In conclusion, miR-124 can play a protective role in temporal lobe epilepsy by promoting PI3K/Akt signaling pathway, including the protection of cognitive function, which may be a potential target for clinical treatment of intractable epilepsy in the future.

Peripheral Nerve Injury in Thoracic Surgery Detected by Automated Somatosensory Evoked Potential Monitoring.

Study Objective. Our objectives were to estimate the incidence of symptoms of peripheral nerve injury (sPNI) in thoracic surgical patients undergoing video-assisted thoracic surgery or open thoracotomy and to determine whether intraoperative somatosensory evoked potentials (SSEPs) waveform changes correlate with postoperative peripheral neuropathic symptoms. Methods. We conducted a prospective observational study in the operating room of a tertiary hospital. We measured SSEPs intraoperatively and assessed patients for sPNI postoperatively. Results. Forty-four patients consented. Six were excluded from analysis. We found that 42% (95% confidence interval [CI] = 26% to 57%) of patients undergoing thoracic surgery had significant changes in SSEP amplitude and latency. Furthermore, 16% (95% CI = 4% to 28%) of patients had new postoperative symptoms of sensory or motor deficits in an upper extremity. We calculated a sensitivity of 66.7% (95% CI = 29.0% to 100%) and a specificity of 50% (95% CI = 33% to 67.3%) for the identification of sPNI based on automated intraoperative SSEP changes. Conclusions. We identified the incidence of SSEP changes in thoracic surgery (42%) and the incidence of postoperative sPNI after thoracic surgery (16%). We identified a positive correlation between intraoperative SSEP changes and postoperative sPNI, which after multivariate analysis was not significant given the small sample size of the study. By the time sensory and/or motor changes are detected postoperatively, it may be too late to reverse the nerve damage. Future versions of the EPAD device could provide anesthesiologists a way to monitor for the development of sPNI, and make changes before a potential injury becomes permanent.

Modafinil reduces choice impulsivity while increasing motor activity in preadolescent rats treated prenatally with alcohol

Rats exposed prenatally to alcohol show a reduction in the spontaneous activity of dopaminergic neurons of the ventral tegmental area (VTA), as well as greater impulsive behavior and motor activity, behavioral alterations that have been related to dopaminergic dysfunction. Modafinil (MOD) is a dopamine (DA) reuptake blocker prescribed to treat sleep disorders; however, in recent years it has been used for the treatment of ADHD with positive results. Also, studies in humans and rodents show beneficial effects on learning and attention; however, studies evaluating MOD effects on impulsivity are few and show contradictory results. The purpose of this work was to evaluate the effect of a daily dose of MOD (60 mg/kg i.g.) on cognitive (or choice) impulsivity and motor activity in male preadolescent rats exposed prenatally to alcohol or sucrose (isocaloric control). MOD reduced the impulsive responses in a delay discounting task (DDT) at the same time that increased the motor activity, in both healthy and prenatal alcohol treated rats; however, MOD reduced the response latency in DDT only in prenatal alcohol treated rats. This differential effect of DA activation on impulsivity and motor activity show that the MOD dose that improves the impulse control, does not necessarily decrease motor activity, and suggests a possible differential neural mechanism underlying the expression of these behaviors. On the other hand, the changes in the response latency, only in prenatal alcohol treated groups, suggest that decision-making in animals with a dopaminergic dysfunction is more susceptible to be affected by MOD action.

Effects of aging on event-related potentials to single-cycle binaural beats and diotic amplitude modulation of a tone

Aim of the study is to determine whether the auditory processing of temporal fine structure (TFS) is affected with normal aging, even in the presence of normal audiometric hearing and fine cognitive state; and, if it is, to see whether a comparable effect is also observed in the processing of a diotic change in sound envelope. The event-related potentials (ERPs) to binaural beats (BBs), which are the responses of the binaural mechanisms processing TFS of a sound, and the ERPs to diotic amplitude modulation (AM) stimuli, which are the responses of the monaural mechanisms processing the changes in its envelope, were recorded from thirteen young university students and ten senior but active university professors, all with normal hearing in low frequencies. To obtain directly the specific BB responses without confounding monaural frequency change-evoked responses, we used single-cycle BB stimuli with temporary sub-threshold frequency shifts. BBs of a 250-Hz tone and diotic AM of the same tone with similar perceptual salience were presented with 2-second stimulus onset asynchrony. The N1 components of the ERPs to both stimuli displayed notable age-dependent changes in their scalp topography and significant amplitude reduction and latency prolongation in the elderly. These amplitude and latency changes were at similar rates for the two stimulus types, implying that the auditory TFS and envelope processing mechanisms are proportionally affected by physiological aging. These results may serve as control data in future studies investigating the effect of aging-associated cognitive pathologies on auditory TFS processing.

Varying effect of noise on sound onset and acoustic change evoked auditory cortical N1 responses evoked by a vowel-vowel stimulus

IntroductionAccording to previous studies noise causes prolonged latencies and decreased amplitudes in acoustic change evoked cortical responses. Particularly for a consonant-vowel stimulus, speech shaped noise leads to more pronounced changes on onset evoked response than acoustic change evoked response. Reasoning that this may be related to the spectral characteristics of the stimuli and the noise, in the current study a vowel-vowel stimulus (/ui/) was presented in white noise during cortical response recordings. The hypothesis is that the effect of noise will be higher on acoustic change N1 compared to onset N1 due to the masking effects on formant transitions. MethodsOnset and acoustic change evoked auditory cortical N1-P2 responses were obtained from 21 young adults with normal hearing while presenting 1000 ms /ui/ stimuli in quiet and in white noise at +10 dB and 0 dB signal-to-noise ratio (SNR). ResultsIn the quiet and +10 dB SNR conditions, the N1-P2 responses to both onset and change were present. In the +10 dB SNR condition acoustic change N1-P2 peak-to-peak amplitudes were reduced and N1 latencies were prolonged compared to the quiet condition. Whereas there was not a significant change in onset N1 latencies and N1-P2 peak-to-peak amplitudes in the +10 dB SNR condition. In the 0 dB SNR condition change responses were not observed but onset N1-P2 peak-to-peak amplitudes were significantly lower, and onset N1 latencies were significantly higher compared to the quiet and the 10 dB SNR conditions. Onset and change responses were also compared with each other in each condition. N1 latencies and N1-P2 peak to peak amplitudes of onset and acoustic change were not significantly different in the quiet condition. Whereas at 10 dB SNR, acoustic change N1 latencies were higher and N1-P2 amplitudes were lower than onset latencies and amplitudes. To summarize, presentation of white noise at 10 dB SNR resulted in the reduction of acoustic change evoked N1-P2 peak-to-peak amplitudes and the prolongation of N1 latencies compared to quiet. Same effect on onsets were only observed at 0 dB SNR, where acoustic change N1 was not observed. In the quiet condition, latencies and amplitudes of onsets and changes were not different. Whereas at 10 dB SNR, acoustic change N1 latencies were higher, amplitudes were lower than onset N1. Discussion/conclusionsThe effect of noise was found to be higher on acoustic change evoked N1 response compared to onset N1. This may be related to the spectral characteristics of the utilized noise and the stimuli, possible differences in acoustic features of sound onsets and acoustic changes, or to the possible differences in the mechanisms for detecting acoustic changes and sound onsets. In order to investigate the possible reasons for more pronounced effect of noise on acoustic changes, future work with different vowel-vowel transitions in different noise types is suggested.