Sample records for c-fibres evokes prolonged

  1. Prognosis in prolonged coma patients with diffuse axonal injury assessed by somatosensory evoked potential

    Xiujue Zheng; Mantao Chen; Jingqi Li; Fei Cao


    A total of 43 prolonged coma patients with diffuse axonal injury received the somatosensory evoked potential examination one month after injury in the First Affiliated Hospital, School of Medicine, Zhejiang University in China. Somatosensory evoked potentials were graded as normal, abnormal or absent (grades I–III) according to N20 amplitude and central conduction time. The outcome in patients with grade III somatosensory evoked potential was in each case unfavorable. The prognostic accuracy of grade III somatosensory evoked potential for unfavorable and non-awakening outcome was 100% and 80%, respectively. The prognostic accuracy of grade I somatosensory evoked potential for favorable and wakening outcome was 86% and 100%, respectively. These results suggest that somatosensory evoked potential grade is closely correlated with coma severity and degree of recovery. Somatosensory evoked potential is a valuable diagnostic tool to assess prognosis in prolonged coma patients with diffuse axonal injury.

  2. Auditory evoked potentials in the auditory system of a beluga whale Delphinapterus leucas to prolonged sound stimuli.

    Popov, Vladimir V; Sysueva, Evgenia V; Nechaev, Dmitry I; Rozhnov, Vyatcheslav V; Supin, Alexander Ya


    The effects of prolonged (up to 1500 s) sound stimuli (tone pip trains) on evoked potentials (the rate following response, RFR) were investigated in a beluga whale. The stimuli (rhythmic tone pips) were of frequencies of 45, 64, and 90 kHz at levels from 20 to 60 dB above threshold. Two experimental protocols were used: short- and long-duration. For the short-duration protocol, the stimuli were 500-ms-long pip trains that repeated at a rate of 0.4 trains/s. For the long-duration protocol, the stimuli were continuous pip successions lasting up to 1500 s. The RFR amplitude gradually decreased by three to seven times from 10 ms to 1500 s of stimulation. Decrease of response amplitude during stimulation was approximately proportional to initial (at the start of stimulation) response amplitude. Therefore, even for low stimulus level (down to 20 dB above the baseline threshold) the response was never suppressed completely. The RFR amplitude decay that occurred during stimulation could be satisfactorily approximated by a combination of two exponents with time constants of 30-80 ms and 3.1-17.6 s. The role of adaptation in the described effects and the impact of noise on the acoustic orientation of odontocetes are discussed. PMID:27036247

  3. [Prediction by means of endogenous and exogenous evoked potentials of the favorable evolution of a prolonged coma].

    Michel, C; Denison, S; Minne, C; Guérit, J M


    A neurophysiological follow-up (EEG, exogenous and endogenous evoked potentials--EP) was performed over a 4-month period in a patient who presented a long-lasting coma following a cardiac arrest and an amniotic embolism. A pure anoxic aetiology was ruled out starting from the second day on the basis of a dissociation between mildly altered flash visual EP and markedly altered somatosensory EP, indicating focal brain-stem pathology. Endogenous EP reappeared after 12 days. This patient recovered consciousness after 51 days. Despite the absence of MRI abnormalities, we put forward the hypothesis that a brain-stem embolism had, in fact, worsened the clinical picture of an actually moderate anoxia. This case exemplifies the interest of an integrated neurophysiological approach (EEG, exogenous three-modality EP and endogenous EP) in the early evaluation of coma. It also illustrates the complement between structural imaging and functional assessment of the nervous system. PMID:9793066

  4. Pathological C-fibres in patients with a chronic painful condition.

    Ørstavik, Kristin; Weidner, Christian; Schmidt, Roland; Schmelz, Martin; Hilliges, Marita; Jørum, Ellen; Handwerker, Herman; Torebjörk, Erik


    Little is known about the contribution of C-afferent fibres to chronic painful conditions in humans. We sought to investigate the role of C-fibres in the pathophysiology of pain and hyperalgesia in erythromelalgia as a model disease for chronic pain. Erythromelalgia is a condition characterized by painful, red and hot extremities, and patients often report tenderness on walking. We made microneurographic recordings from single C-fibres in cutaneous fascicles of the peroneal nerve in patients suffering from this disease. All patients had had a pain attack recently and psychophysical signs of allodynia and punctate hyperalgesia were found. We obtained recordings from a total of 103 C-fibres and found significantly lower conduction velocities and increased activity-dependent slowing of the conduction velocity of afferent C-fibres in the patients compared with healthy controls. Furthermore, several units with biophysical properties of mechano-insensitive fibres were pathological, being spontaneously active or sensitized to mechanical stimuli. Since these fibres also mediate the axon reflex flare, their hyperexcitability might account not only for ongoing pain and tenderness but also for redness and warming in this pain syndrome. The changes in conductive properties found in the C-fibres of these patients could be the first signs of a small-fibre neuropathy. This is the first systematic study of single C-fibres in patients and it shows an active contribution of mechano-insensitive fibres to chronic pain. PMID:12566278

  5. Time course of post-excitatory effects separates afferent human C fibre classes.

    Weidner, C; Schmidt, R; Schmelz, M; Hilliges, M; Handwerker, H O; Torebjörk, H E


    1. To study post-excitatory changes of conduction velocity, action potentials were recorded from 132 unmyelinated nerve fibres (C fibres) in cutaneous fascicles of the peroneal nerve using microneurography in healthy human subjects. The 'marking' technique was used to assess responsiveness to mechanical and heat stimuli or sympathetic reflex provocation. 2. C fibres were classified into three major classes: mechano-responsive afferent (n = 76), mechano-insensitive afferent (n = 48) and sympathetic efferent C fibres (n = 8). 3. During regular stimulation at 0.25 Hz, conditioning pulses were intermittently interposed. Changes of conduction velocity were assessed for different numbers of conditioning impulses and varying interstimulus intervals (ISIs). For all three fibre classes the latency shift following conditioning pulses at an ISI of 1000 ms increased linearly with their number (n = 1, 2 and 4). However, the absolute degree of conduction velocity slowing was much higher in the 32 mechano-insensitive fibres as compared with 56 mechano-responsive or 8 sympathetic fibres. 4. Single additional pulses were interposed at different ISIs from 20 to 2000 ms. For 20 mechano-responsive fibres conduction velocity slowing increased with decreasing ISI (subnormal phase). In contrast, for 16 mechano-insensitive C fibres the conduction velocity slowing decreased with shorter ISIs, and at values lower than 417 +/- 49 ms (mean +/- s.e.m.) the conduction velocity of the conditioned action potential was faster than before (conduction velocity speeding). This supernormal phase had its maximum at 69 +/- 10 ms. 5. In this study we provide, for the first time, direct evidence of relative supernormal conduction in human mechano-insensitive C fibres. The implications for temporal coding in different afferent C fibre classes are discussed. PMID:10944181

  6. Interfacial characterisation in transparent spinel matrix reinforced by SiC fibre

    Chlup, Zdeněk; Dlouhý, Ivo; Gürbüz, S.; Dericioglu, A. F.; Kozák, Vladislav


    Roč. 409, - (2009), s. 252-259. ISSN 1013-9826. [Fractography of Advanced Ceramics III. Stará Lesná, 07.09.20058-10.09.2008] R&D Projects: GA ČR(CZ) GA106/06/0724; GA AV ČR IAA200410502 Institutional research plan: CEZ:AV0Z20410507 Keywords : interface * composite * transparent spinel * SiC fibre * fracture characteristics Subject RIV: JI - Composite Materials

  7. SiC fibre by chemical vapour deposition on tungsten filament

    R V Krishnarao; J Subrahmanyam; S Subbarao


    A CVD system for the production of continuous SiC fibre was set up. The process of SiC coating on 19 m diameter tungsten substrate was studied. Methyl trichloro silane (CH3SiCl3) and hydrogen reactants were used. Effect of substrate temperature (1300–1500°C) and concentration of reactants on the formation of SiC coating were studied. SiC coatings of negligible thickness were formed at very low flow rates of hydrogen (5 × 10–5 m3/min) and CH3SiCl3 (1.0 × 10–4 m3/min of Ar). Uneven coatings and brittle fibres were formed at very high concentrations of CH3SiCl3 (6 × 10–4 m3/min of Ar). The flow rates of CH3SiCl3 and hydrogen were adjusted to get SiC fibre with smooth surface. The structure and morphology of SiC fibres were evaluated.

  8. Psychophysical Investigations into the Role of Low-Threshold C Fibres in Non-Painful Affective Processing and Pain Modulation.

    Sumaiya Shaikh

    Full Text Available We recently showed that C low-threshold mechanoreceptors (CLTMRs contribute to touch-evoked pain (allodynia during experimental muscle pain. Conversely, in absence of ongoing pain, the activation of CLTMRs has been shown to correlate with a diffuse sensation of pleasant touch. In this study, we evaluated (1 the primary afferent fibre types contributing to positive (pleasant and negative (unpleasant affective touch and (2 the effects of tactile stimuli on tonic muscle pain by varying affective attributes and frequency parameters. Psychophysical observations were made in 10 healthy participants. Two types of test stimuli were applied: stroking stimulus using velvet or sandpaper at speeds of 0.1, 1.0 and 10.0 cm/s; focal vibrotactile stimulus at low (20 Hz or high (200 Hz frequency. These stimuli were applied in the normal condition (i.e. no experimental pain and following the induction of muscle pain by infusing hypertonic saline (5% into the tibialis anterior muscle. These observations were repeated following the conduction block of myelinated fibres by compression of sciatic nerve. In absence of muscle pain, all participants reliably linked velvet-stroking to pleasantness and sandpaper-stroking to unpleasantness (no pain. Likewise, low-frequency vibration was linked to pleasantness and high-frequency vibration to unpleasantness. During muscle pain, the application of previously pleasant stimuli resulted in overall pain relief, whereas the application of previously unpleasant stimuli resulted in overall pain intensification. These effects were significant, reproducible and persisted following the blockade of myelinated fibres. Taken together, these findings suggest the role of low-threshold C fibres in affective and pain processing. Furthermore, these observations suggest that temporal coding need not be limited to discriminative aspects of tactile processing, but may contribute to affective attributes, which in turn predispose individual

  9. Responses of motor units during the hind limb flexion withdrawal reflex evoked by noxious skin heating: phasic and prolonged suppression by midbrain stimulation and comparison with simultaneously recorded dorsal horn units.

    Carstens, E; Campell, I G


    In rats anesthetized with sodium pentobarbital, we quantitatively analyzed descending modulation from the midbrain of a nociceptive flexion withdrawal reflex and responses of associated spinal neurons. We monitored the isometric force of hind limb withdrawal elicited by noxious heat stimuli (42-54 degrees C, 10 sec) on the hind paw. In one series of experiments, single-fiber EMG electrodes recorded responses of single muscle fibers (i.e., motor units) in biceps femoris during the hind limb withdrawal, without and during electrical stimulation in the midbrain periaqueductal gray (PAG) or lateral midbrain reticular formation (LRF). In a second series, responses of single lumbar dorsal horn neurons were also recorded simultaneously. Withdrawal force and associated motor unit responses were suppressed for prolonged periods (4 to greater than 60 min) following the initial episode of PAG or LRF stimulation in 40% of the rats, while they were suppressed phasically (i.e., only during brain stimulation) in the remainder. Motor unit responses increased in a graded fashion with increasing skin stimulus temperature from threshold (45 degrees C) to 54 degrees C. During PAG stimulation, the slope of the rate coding function was reduced with no change in threshold temperature. During LRF stimulation the rate coding function was shifted toward higher temperatures with increased threshold (47 degrees C). In 14 experiments 43 paired recordings were made from a dorsal horn and a motor unit during hind limb withdrawals. Mean latency to onset and peak of the heat-evoked response was shorter for dorsal horn compared to motor units. In 6/14 rats withdrawal force and motor unit responses were significantly suppressed for more than 8 min following mechanical placement of the stimulating electrodes and/or the initial episode of midbrain stimulation, while the simultaneously recorded dorsal horn unit responses remained constant. Following supplemental administration of pentobarbital (10

  10. Changes in tetrodotoxin-resistant C-fibre activity during fatiguing isometric contractions in the rat.

    Ivana Kalezic

    Full Text Available It is by now well established that tetrodotoxin-resistant (TTX-R afferent fibres from muscle in the rat exhibit a multisensitive profile, including nociception. TTX-R afferent fibres play an important role in motor control, via spinal and supraspinal loops, but their activation and function during muscle exercise and fatigue are still unknown. Therefore, the specific effect of isometric fatiguing muscle contraction on the responsiveness of TTX-R C-fibres has been investigated in this study. To quantify the TTX-R afferent input we recorded the cord dorsum potential (CDP, which is the result of the electrical fields set up within the spinal cord by the depolarisation of the interneurons located in the dorsal horn, activated by an incoming volley of TTX-R muscle afferents. The changes in TTX-R CDP size before, during and after fatiguing electrical stimulation of the gastrocnemius-soleus (GS muscle have been taken as a measure of TTX-R C-unit activation. At the end of the fatiguing protocol, following an exponential drop in force, TTX-R CDP area decreased in the majority of trials (9/14 to 0.75 ± 0.03% (mean ± SEM of the pre-fatigue value. Recovery to the control size of the TTX-R CDP was incomplete after 10 min. Furthermore, fatiguing trials could sensitise a fraction of the TTX-R C-fibres responding to muscle pinch. The results suggest a long-lasting activation of the TTX-R muscle afferents after fatiguing stimulation. The role of this behaviour in chronic muscle fatigue in connection with pain development is discussed. Accumulation of metabolites released into the interstitium during fatiguing stimulation might be one of the reasons underlying the C-fibres' long-lasting activation.

  11. Crack growth in glass matrix composite reinforced by long SiC fibres

    Kotoul, M.; Vysloužil, T.; Boccaccini, A. R.; Dlouhý, Ivo


    Roč. 49, č. 2 (2008), s. 158-170. ISSN 0167-8442 R&D Projects: GA ČR(CZ) GA101/05/0320; GA ČR(CZ) GA106/05/0495; GA ČR(CZ) GA106/06/0724 Institutional research plan: CEZ:AV0Z20410507 Keywords : brittle matrix composites * SiC fibres * Chevron-notch specimen * crack bridging * R-curve modelling * Weight functions Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.011, year: 2008

  12. Synaptically evoked dendritic action potentials in rat neocortical pyramidal neurons.

    Schwindt, P C; Crill, W E


    In a previous study iontophoresis of glutamate on the apical dendrite of layer 5 pyramidal neurons from rat neocortex was used to identify sites at which dendritic depolarization evoked small, prolonged Ca2+ spikes and/or low-threshold Na+ spikes recorded by an intracellular microelectrode in the soma. These spikes were identified as originating in the dendrite. Here we evoke similar dendritic responses by electrical stimulation of presynaptic elements near the tip of the iontophoretic electrode with the use of a second extracellular electrode. In 9 of 12 recorded cells, electrically evoked excitatory postsynaptic potentials (EPSPs) above a minimum size triggered all-or-none postsynaptic responses similar to those evoked by dendritic glutamate iontophoresis at the same site. Both the synaptically evoked and the iontophoretically evoked depolarizations were abolished reversibly by blockade of glutamate receptors. In all recorded cells, the combination of iontophoresis and an EPSP, each of which was subthreshold for the dendritic spike when given alone, evoked a dendritic spike similar to that evoked by a sufficiently large iontophoresis. In one cell tested, dendritic spikes could be evoked by the summation of two independent subthreshold EPSPs evoked by stimulation at two different locations. We conclude that the dendritic spikes are not unique to the use of glutamate iontophoresis because similar spikes can be evoked by EPSPs. We discuss the implications of these results for synaptic integration and for the interpretation of recorded synaptic potentials. PMID:9582218

  13. Brainstem evoked potentials in infantile spasms

    In ten patients with infantile spasms, brainstem evoked potentials and MRI examinations were performed to evaluate the brainstem involvement. The result of short latency somatosensory evoked potentials (SSEP) following the right median nerve stimulation revealed abnormal findings including the absence or low amplitudes of the waves below wave P3 and delayed central conduction time in 7 of the ten patients. The result of auditory brainstem responses (ABR) revealed abnormal findings including low amplitudes of wave V, prolonged interpeak latency of waves I-V and absence of the waves below wave IV in 5 of the ten patients. The result of the MRI examinations revealed various degrees of the brainstem atrophy in 6 of the ten patients, all of whom showed abnormal brainstem evoked potentials. The result of this study demonstrates that patients with infantile spasms are frequently associated with brainstem dysfunction and raises the possibility that brainstem atrophy might be a cause of infantile spasms. (author)

  14. Peak latency prolongation of Ⅴ wave in brainstem auditory evoked potential during intraoperative monitoring of acoustic neuroma surgery%脑干听觉诱发电位的Ⅴ波PL延长在听神经瘤手术监护中的应用价值

    包国庆; 朱沂; 李建新; 杨小朋


    目的 探讨BAEP的Ⅴ波PL延长在听神经瘤手术中的应用价值. 方法 回顾性分析55例听神经瘤手术患者行BAEP术前检查、术中监护及术后疗效评估,分析Ⅴ波PL延长不同指标的监测结果. 结果 以Ⅴ波PL延长>0.6 ms为标准,脑干或听神经损伤的灵敏度100%,特异度95.3%,误诊率4.7%,漏诊率0%,符合率96.4%.以Ⅴ波PL延长>1.0 ms为标准,灵敏度58.3%,特异度97.7%,误诊率2.3%,漏诊率41.7%,符合率89.1%. 结论 BAEP监护听神经瘤手术中,V波PL延长>0.6 ms有较高的敏感度和特异度,作为术中监护报警指标更合适.%Objective To explore the applied value of peak latency (PL) prolongation of Ⅴ wave in brainstem auditory evoked potential (BAEP) during intraoperative monitoring of acoustic neuroma surgery. Methods The preoperative BAEP examination data,intraoperative monitoring and postoperative evaluation data in 55 patients with acoustic neuroma were retrospectively analyzed; the monitoring results under the circumstance that different degrees of prolongation of PL of Ⅴ wave were chosen were analyzed. Results The PL prolongation of Ⅴ wave >0.6 ms was used as the baseline,the sensitivity of diagnosing the brainstem or acoustic nerve injury was 100%,the specificity was 95.3%,the misdiagnosis rate was 4.7%,the missed diagnosis rate was 0% and the accordance rate was 96.4%.The PL prolongation of Ⅴ wave >1.0 ms was used as the baseline,the sensitivity of diagnosing the brainstem or acoustic nerve injury was 58.3%,the specificity was 97.7%,the misdiagnosis rate was 2.3%,the missed diagnosis rate was 41.7% and the accordance rate was 89.1%. Conclusion It is more suitable that using thePL prolongation of Ⅴ wave >0.6 ms as the baseline,enjoying high sensitivity and specificity,during the intraoperative monitoring of acoustic neuroma.

  15. Proprioceptive evoked gamma oscillations

    Arnfred, Sidse M; Hansen, Lars Kai; Parnas, Josef;


    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able to...

  16. Contact heat evoked potentials using simultaneous EEG and fMRI and their correlation with evoked pain

    Atherton Duncan


    Full Text Available Abstract Background The Contact Heat Evoked Potential Stimulator (CHEPS utilises rapidly delivered heat pulses with adjustable peak temperatures to stimulate the differential warm/heat thresholds of receptors expressed by Aδ and C fibres. The resulting evoked potentials can be recorded and measured, providing a useful clinical tool for the study of thermal and nociceptive pathways. Concurrent recording of contact heat evoked potentials using electroencephalogram (EEG and functional magnetic resonance imaging (fMRI has not previously been reported with CHEPS. Developing simultaneous EEG and fMRI with CHEPS is highly desirable, as it provides an opportunity to exploit the high temporal resolution of EEG and the high spatial resolution of fMRI to study the reaction of the human brain to thermal and nociceptive stimuli. Methods In this study we have recorded evoked potentials stimulated by 51°C contact heat pulses from CHEPS using EEG, under normal conditions (baseline, and during continuous and simultaneous acquisition of fMRI images in ten healthy volunteers, during two sessions. The pain evoked by CHEPS was recorded on a Visual Analogue Scale (VAS. Results Analysis of EEG data revealed that the latencies and amplitudes of evoked potentials recorded during continuous fMRI did not differ significantly from baseline recordings. fMRI results were consistent with previous thermal pain studies, and showed Blood Oxygen Level Dependent (BOLD changes in the insula, post-central gyrus, supplementary motor area (SMA, middle cingulate cortex and pre-central gyrus. There was a significant positive correlation between the evoked potential amplitude (EEG and the psychophysical perception of pain on the VAS. Conclusion The results of this study demonstrate the feasibility of recording contact heat evoked potentials with EEG during continuous and simultaneous fMRI. The combined use of the two methods can lead to identification of distinct patterns of brain

  17. Evoked acoustic emission

    Elberling, C; Parbo, J; Johnsen, N J;


    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...... a minor effect on the power spectra, i.e. the maximum jumps from one spectral peak to another. Experiments with deconvolution demonstrate that the emission generating system at least at a fixed intensity can be regarded as being linear and characterized by its impulse response which is similar to...... the emission evoked by click stimuli. It is concluded that significant information is obtained by the click rather than by the tonal stimuli. The click-evoked emissions were also recorded from both ears in a consecutive series of 100 full-term and otherwise normal babies 2-4 days after birth. The...

  18. Proprioceptive evoked gamma oscillations

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.; Mørup, Morten


    evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure of...

  19. Application of Al2O3:C+fibre dosimeters for 290 MeV/n carbon therapeutic beam dosimetry

    The capability of radioluminescence (RL) dosimeters composed of carbon-doped aluminium oxide (Al2O3:C) detectors+optical fibre has been verified for absorbed dose-rate measurements during carbon radiotherapy. The RL signals from two separate Al2O3:C detectors (single crystal 'CG' and droplet 'P1') have been systematically measured and compared along the Bragg-curve and Spread-Out Bragg-Peak of 290 MeV/n carbon beams in the water. The absorbed dose response was assessed for the range of 0.5–10 Gy. For doses up to 6 Gy, we observed a linear response for both types of detectors, while for higher doses CG presented a more prominent supraliearity than P1. The RL response for low-LET protons in the entrance from the curve was found to closely resemble that observed for a clinical 6 MV X-ray beam, while it was found that P1 has a better agreement with the reference data from standard ionization chamber than CG. We observed a significant decrease in luminescence efficiency with LET in the Bragg peak region. The Al2O3:C RL luminescence efficiency differs from Al2O3:C OSL results, which implies that the signal can be corrected for LET dependency to match the correct SOBP and Bragg Peak. - Highlights: • Radioluminescence (RL) real time signal from Al2O3:C+fibre probes. • Irradiations with 290 MeV/n Carbon. • Two types of detectors were tested: droplet and single crystal. • Luminescence efficiencies for each probe were compared with 6 MV photons. • Bragg Peak and SOBP are obtained. • Luminescence efficiencies for Optically Stimulated Luminescence (OSL) and RL are compared for Al2O3:C

  20. Motor evoked potential polyphasia

    Chowdhury, Fahmida A.; Pawley, Adam D.; Ceronie, Bryan; Nashef, Lina; Robert D C Elwes; Richardson, Mark P


    Objective: We compared the motor evoked potential (MEP) phases using transcranial magnetic stimulation in patients with idiopathic generalized epilepsy (IGE), their relatives, and healthy controls, hypothesizing that patients and their unaffected relatives may share a subtle pathophysiologic abnormality. Methods: In a cross-sectional study, we investigated 23 patients with IGE, 34 first-degree relatives, and 30 matched healthy controls. Transcranial magnetic stimulation was performed to produ...

  1. Selecting and evoking innovators

    Kanstrup, Anne Marie; Christiansen, Ellen


    The practical undertaking of selecting users to work as innovators and of evoking their creative potential is crucial, but underexposed in the literature on user involvement in design. This paper reports findings from a recent case of user-driven innovation, the FEEDBACK-project, where the author...... theories of learning we try to explain how our way of working with selection and evoking of innovators has contributed to this positive result and how our approach to user-driven innovation can be regarded as a way to combine democracy and creativity in design.......The practical undertaking of selecting users to work as innovators and of evoking their creative potential is crucial, but underexposed in the literature on user involvement in design. This paper reports findings from a recent case of user-driven innovation, the FEEDBACK-project, where the authors...... prepared for and conducted selection of and collaboration with innovators. The outcome was successful in the sense that the innovators produced excellent foundation for conceptual interaction design by creating mock-ups and explanations incarnating their preferences, attitudes and habits. By referring to...


    LU Yingzhi; ZONG Wenbin; CHEN Xingshi


    Objective: In order to investigate the brain function of patients with Qigong induced mental disorder (QIMD), this study was carried out. Methods: Four kinds of evoked potentials, including contingent negative variation (CNV), auditory evoked potentials (AEP), visual evoked potentials (VEP), and somatosensory evoked potentials (SEP), were recorded from 12 patients with Qigong induced mental disorder.Comparison of their evoked potentials with the data from some normal controls was made. Results: The results revealed that there were 3 kinds of abnormal changes in evoked potentials of patients with QIMD that is latency prolongation, amplitude increase and amplitude decrease, as compared with normal controls. Conclusion: Brain dysfunction of patients with QIMD was confirmed. Its biological mechanism needs further studying.

  3. International Evoked Potentials Symposium


    The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

  4. Multimodality evoked potentials in HTLV-I associated myelopathy.

    Kakigi, R; Shibasaki, H; Kuroda, Y; Endo, C; Oda, K.; Ikeda, A.; Hashimoto, K.


    Multimodality evoked potentials (EPs) consisting of somatosensory EPs (SEPs), visual EPs (VEPs) and brainstem auditory EPs (BAEPs) were studied in 16 cases with HTLV-I associated myelopathy (HAM). Median nerve SEPs were normal in all cases. In posterior tibial nerve SEPs, the potential recorded at the 12th thoracic spinal process was normal in every case but cortical components were significantly prolonged in 10 cases, although five of these showed no sensory impairment. BAEPs were normal in ...

  5. Event-related evoked potentials in chronic respiratory encephalopathy

    Tahan, A R Al; Zaidan, R.; Jones, S; Husain, A.; Mobeireek, A; Bahammam, A


    Background: Cognitive event-related potential (P300) is an index of cognitive processing time. It was found to be prolonged in dementia, renal, and hepatic encephalopathies, but was not extensively assessed in respiratory failure. Objective: To evaluate P300 changes in patients with respiratory failure, and especially those with mild or subclinical hypoxic–hypercapnic encephalopathy. Methods: Auditory event-related evoked potential P300 latency was measured using an oddball paradigm in patien...

  6. Music evokes vivid autobiographical memories.

    Belfi, Amy M; Karlan, Brett; Tranel, Daniel


    Music is strongly intertwined with memories-for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces. PMID:26259098

  7. Achieving Presence through Evoked Reality

    Jayesh S.Pillai


    Full Text Available The sense of ‘Presence’ (evolving from ‘telepresence’ has always been associated with virtual reality research and is still an exceptionally mystifying constituent. Now the study of presence clearly spans over various disciplines associated with cognition. This paper attempts to put forth a concept that argues that it’s an experience of an 'Evoked Reality’ (illusion of reality that triggers an ‘Evoked Presence’ (sense of presence in our minds. A Three Pole Reality Model is proposed to explain this phenomenon. The poles range from Dream Reality to Simulated Reality with Primary (Physical Reality at the center. To demonstrate the relationship between Evoked Reality and Evoked Presence, a Reality-Presence Map is developed. We believe that this concept of Evoked Reality and the proposed model may have significant applications in the study of presence, and in exploring the possibilities of not just virtual reality but also what we call ‘reality’.

  8. The isolated prolonged PTT.

    Tcherniantchouk, Oxana; Laposata, Michael; Marques, Marisa B


    It is increasingly difficult to choose the proper tests to investigate an abnormal laboratory result, delaying the time to reach the correct diagnosis and increasing the cost of care. A wrong choice may also lead to clinically significant errors, which can be life threatening. To show how errors in test selection occur in routine medical practice, the authors describe an algorithm to evaluate patients with a prolonged activated partial thromboplastin time (PTT) and a normal prothrombin time. This exercise challenges the commonly held belief that errors in laboratory utilization occur primarily with esoteric and/or genetic testing, rather than in patients with common abnormalities such as a prolonged PTT. PMID:22811044

  9. Exhaustion from prolonged gambling

    Fatimah Lateef


    Complaints of fatigue and physical exhaustion are frequently seen in the acute medical setting, especially amongst athletes, army recruits and persons involved in strenuous and exertional physical activities.Stress-induced exhaustion, on the other hand, is less often seen, but can present with very similar symptoms to physical exhaustion.Recently, three patients were seen at theDepartment ofEmergencyMedicine, presenting with exhaustion from prolonged involvement in gambling activities.The cases serve to highlight some of the physical consequences of prolonged gambling.

  10. Evoked emotions predict food choice.

    Jelle R Dalenberg

    Full Text Available In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA and apply Multinomial Logit Models (MLM to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively. After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores.

  11. Evoked emotions predict food choice.

    Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry


    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores. PMID:25521352

  12. Electrically evoked itch in humans.

    Ikoma, Akihiko; Handwerker, Hermann; Miyachi, Yoshiki; Schmelz, Martin


    We compared itch sensations and axon reflex flare induced by transcutaneous electrical (0.08-8 ms, 2-200 Hz) and chemical (histamine iontophoresis; 100 microC) stimulation. Stimuli were applied to non-lesional volar wrist skin in 20 healthy human subjects and 10 patients with atopic dermatitis. Intensity of evoked itch and pain sensations were rated on a numerical rating scale (NRS) of 0 (no sensation) to 10 (the maximum sensation imaginable). The axon reflex erythema was measured by laser Doppler imager and areas of alloknesis (itch evoked by light brushing) and hyperknesis (itch evoked by pricking) were assessed psychophysically. Electrical stimulation was most effective for stimulus durations >or=2 ms and frequencies >or=50 Hz. It evoked pure itch as threshold sensation in 80% of the subjects that was perceived with a delay of approximately 1 s. Itch intensities of up to 7/10 were not accompanied by an axon reflex flare. In contrast, histamine provoked a massive increase of axon reflex erythema and maximum itch ratings of 3.1+/-0.2. The extention of alloknesis areas (2.3+/-0.5 cm) evoked by electrical stimulation clearly exceeded those induced by histamine (0.7+/-0.3 cm). Healthy subjects and patients with atopic dermatitis did not differ significantly in their response to either stimulation. We conclude that C-fiber activation underlies the electrically evoked itch sensation. The low electrical thresholds and the absence of an axon reflex flare suggest that these fibers are not identical with the previously described mechano-insensitive histamine responsive C fibers, but represent a separate peripheral neuronal system for the induction of itch. PMID:15621375

  13. Evoked Emotions Predict Food Choice

    Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry


    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Th

  14. Management of prolonged pregnancy

    Objective: To compare two strategies for management of prolonged pregnancy (= or >294 days) i.e. induction (intervention) versus expectant management (non-intervention) and evaluate the associated feto-maternal risks. Subjects and Methods: One hundred cases of uncomplicated prolonged gestation were selected. The gestational age was confirmed by ultrasound in first trimester. One group (50 patients) was managed by intervention i.e. induction of labour (group A) and other group (50 patients) by non-intervention i.e. expectant management (group B). In group A intervention was done at 42 weeks. In expectant group, the methods of monitoring were fetal kick charting recorded daily by the patient, and ultrasound for amniotic fluid index. The biophysical profile score and NST (non stress test) were performed once a week till 42 weeks and then twice weekly. Results: The frequency of prolonged pregnancy was found to be 10.9%. There was no significant difference in the number of spontaneous vaginal deliveries between the two groups. The rate of LSCS (lower segment caesarean section) was higher in intervention group ( 30% versus 18% ). The neonatal depression at birth was more in group B ( 10% versus 4%) and at 5 minutes almost same between two groups (4% versus 2%). There were 11 cases of meconium aspiration syndrome, leading to one neonatal death. Among nine perinatal deaths two were neonatal deaths. Seven cases of intrauterine deaths in which antepartum deaths occurred because of non compliance of patients. No cause could be detected for the other three fetuses. Conclusion: There was increased LSCS rate in group A. However in expectant group B perinatal mortality was about twice more as compared to intervention group. Active early intervention at 42 weeks is warranted to reduce perinatal morbidity and mortality. (author)

  15. Noise-evoked otoacoustic emissions in humans

    Maat, B; Wit, HP; van Dijk, P


    Click-evoked otoacoustic emissions (CEOAEs) and acoustical responses evoked by bandlimited Gaussian noise (noise-evoked otoacoustic emissions; NEOAEs) were measured in three normal-hearing subjects. For the NEOAEs the first- and second-order Wiener kernel and polynomial correlation functions up to t


    Yilmaz, Ugur; Vicars, Brenda; Yang, Claire C.


    We investigated the autonomic innervation of the penis by using evoked cavernous activity (ECA). We recruited 7 males with thoracic spinal cord injury (SCI) and sexual dysfunction and 6 males who were scheduled to have pelvic surgery (PS), specifically non-nerve-sparing radical cystoprostatectomy. In the PS subjects, ECA was performed both pre- and postoperatively. The left median nerve was electrically stimulated and ECA was recorded with two concentric electromyography needles placed into t...

  17. Evoked Emotions Predict Food Choice

    Dalenberg, Jelle R.; Swetlana Gutjar; ter Horst, Gert J.; Kees de Graaf; Renken, Remco J.; Gerry Jager


    In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well ...

  18. The feeding responses evoked by cholecystokinin are mediated by vagus and splanchnic nerves.

    Brown, Thelma A L; Washington, Martha C; Metcalf, Shannon A; Sayegh, Ayman I


    Total or selective branch vagotomy attenuates the reduction of cumulative food intake by cholecystokinin (CCK)-8 and CCK-33 respectively. However, the role of the sympathetic innervation of the gut and the role of the vagus nerve in feeding responses, which include meal size (MS) and intermeal interval (IMI), evoked by CCK-8 and CCK-33 have not been evaluated. Here, we tested the effects of total subdiaphragmatic vagotomy (VGX) and celiaco-mesenteric ganglionectomy (CMGX) on the previous feeding responses by CCK-8 and CCK-33 (0, 1, 3, and 5 nmol/kg given intraperitoneally). We found (1) that both peptides reduced meal size and CCK-8 (5 nmol) and CCK-33 (1 and 3 nmol) prolonged IMI, (2) that VGX attenuated the reduction of MS but failed to attenuate the prolongation of IMI by both peptides and (3) that CMGX attenuated the reduction of meal size by CCK-8 and the prolongation of IMI by both peptides. Therefore, the feeding responses evoked by CCK-8 require intact vagus and splanchnic nerves: the reduction of MS by CCK-33 requires an intact vagus nerve, and the prolongation of IMI requires the splanchnic nerve. These findings demonstrate the differential peripheral neuronal mediation of the feeding responses evoked by CCK-8 and CCK-33. PMID:21745513

  19. Dexmedetomidine infusion and somatosensory evoked potentials.

    Bloom, M; Beric, A; Bekker, A


    Intraoperative neurophysiologic monitoring requires information on the effects of anesthetic drugs because these drugs can directly alter evoked potentials, thus interfering with monitoring. We report on our evaluation of the effect of the recently introduced alpha2-adrenergic agonist, dexmedetomidine, on the somatosensory evoked potentials in two patients undergoing cervico-occipital fusion. Our results suggest that, although dexmedetomidine can affect the later cortical peaks of somatosensory evoked potentials (SSEPs), consistent and reproducible potentials can be recorded. PMID:11733664

  20. Short-latency somatosensory evoked potentials in degenerative and vascular dementia.

    Abbruzzese, G; Reni, L.; Cocito, L; Ratto, S; Abbruzzese, M; Favale, E


    Short-latency somatosensory evoked potentials (SEPs) were recorded from 54 patients with dementia as compared to 32 age-matched controls. SEPs were generally normal in patients with senile dementia of Alzheimer type, while patients with multi-infarct dementia showed a prolonged central conduction time, an increased latency of both N13 and N20 and a reduction of the primary cortical response amplitude. These findings suggest that recording SEPs may be useful in the differential diagnosis betwe...

  1. 含钇聚碳硅烷制备碳化硅纤维%Fabrication of SiC fibres from yttrium-containing polycarbosilane

    杨大祥; 宋永才; 余煜玺; 赵晓峰; 肖平


    将钇元素作为烧结助剂引入到聚碳硅烷(PCS)中制备含钇PCS.由含钇PCS制成siC(OY)和siC(Y)2种碳化硅纤维.对SiC(OY)纤维转变成SiC(Y)纤维的结构与相关特性的变化进行研究.SiC(OY)纤维的化学组成为SiC1.23O0.05Y0.005,纤维是无定型结构;SiC(Y)纤维含有大量的直径为50 nm的β-siC晶粒和少量的α-SiC晶粒,钇元素存在于SiC晶粒之间.SiC(OY)的拉伸强度为2.25 GPa,断裂韧性为2.37 MPa·m1/2; SiC(Y)的拉伸强度为1.61 GPa,断裂韧性为1.91 MPa·m1/2; SiC(Y)纤维比SiC(OV)纤维具有更好的热稳定性.%The yttrium as a sintering aid was introduced into polycarbosilane (PCS) to prepare yttrium-containing PCS (PYCS).Two types of yttrium-containing SiC fibres,the SiC(OY) fibres and the SiC(Y) fibres,were fabricated with PYCS.The structural evolution and the associated properties on changing from SiC(OY) to SiC(Y) fibres during the sintering process were studied.The chemical composition of the SiC(OY) fibres is SiC1.53O0.22Y0.005 with an amorphous structure.The composition of SiC(Y) fibres is SiC1.23O0.05Y0.005.The fibres are composed of a large number of β-SiC crystallites with a size of 50 nm and a small amount of α-SiC crystalline.The tensile strength and fracture toughness of the SiC(OY) fibres are 2.25 GPa and 2.37 MPam1/2,respectively,and 1.61 GPa,1.91 MPa·m1/2,respectively for SiC(Y) fibres.The SiC(Y) fibres have a higher thermal stability than the SiC(OY) fibres.

  2. Prolonged contact lens wear evokes the oxidant/antioxidant imbalance in the corneal epithelium

    Čejková, Jitka


    Roč. 33, Supplement 1 (2001), s. 36. ISSN 0030-3747. [EVER 2002. 10.10.2001-13.10.2001, Alicante] R&D Projects: GA ČR GV307/96/K226; GA ČR GA304/00/1635 Keywords : cornea, contact lenses Subject RIV: FF - HEENT, Dentistry

  3. [The disposing techniques of evoked potentials].

    Liu, H G; Zhou, L; Gu, J; Jing, D Z


    This paper is to bring forward the new disposing techniques of evoked potentials which include four aspect techniques of the averaging, the recording, digital sampling and filters about the averaging, evoked potential amplitude, evoked potential latency, evoked potential recording, and evoked potential generations. The technique of the averaging including signal filtering and a periodic averaging, can enhance EP dedection. The commercial EP machines also plot changes in latency between serial EP studies in order to detect trends in peak latency. The modern digital EP recording device consists of sensory stimator, recording amplifiers with analog filters, an analog-to-digital converter, a digital signal averager, and a display and storage system. A sample-and-hold function is one of the recent developments which used EP collectors that provide simultaneous recording with multiple channels employing different time and voltage scales and sampling rates. The EP data may be further processed following A-D conversion by digital filters. PMID:12583248




    Full Text Available Diabetes mellitus is the most common metabolic disorder affecting majority of population. It is estimated that over 400 million people throughout the world have diabetes. It has progressed to be a pandemic from an epidemic causing morbidity and mortality in the population. Among the many complications of diabetes, diabetic neuropathies contribute majorly to the morbidity associated with the disease. Axonal conduction is affected by elevated levels of protein kinase c causing neuronal ischemia; decreased ce llular myoinositol affecting sodium potassium ATPase pump leads to decreased nerve conduction; Somatosensory E voked P otentials (SSEPs reflect the activity of somatosensory pathways mediated through the dorsal columns of the spinal cord and the specific so matosensory cortex. Recording of Somatosensory Evoked Potentials in diabetics is done to assess the sensory involvement of spinal cord. Presence of SEPs provides clear evidence for axonal continuity and by using different stimulation sites, the rate of reg eneration can be determined. Both onset and peak latencies of all SEP components are prolonged in patients with diabetes. Present study is done to compare somatosensory evoked potentials in diabetics and normal subjects. MATERIALS AND METHOD S: The present study was undertaken at the Upgraded Department of Physiology, Osmania Medical College, Koti, Hyderabad. The study was conducted on subjects, both male and female in the age group of 45 to 55 years, suffering from type II diabetes excluding other neurologi cal disorders. Non - invasive method of estimation of nerve conduction studies using SFEMG/EP — Electromyography or evoked potential system (Nicolet systems — USA using surface electrodes with automated computerized monitor attached with printer is used. RESUL TS : ANOVA showed statistically significant N9 latency (right & left sides. Latencies of all the components of SSEPs were more significant than amplitudes in Diabetic

  5. Hyperthyroidism Evokes Myocardial Ceramide Accumulation

    Agnieszka Mikłosz


    Full Text Available Background: Thyroid hormones (THs are key regulators of cardiac physiology as well as modulators of different cellular signals including the sphingomyelin/ceramide pathway. The objective of this study was to examine the effect of hyperthyroidism on the metabolism of sphingolipids in the muscle heart. Methods: Male Wistar rats were treated for 10 days with triiodothyronine (T3 at a dose of 50µg/100g of body weight. Animals were then anaesthetized and samples of the left ventricle were excised. Results: We have demonstrated that prolonged, in vivo, T3 treatment increased the content of sphinganine (SFA, sphingosine (SFO, ceramide (CER and sphingomyelin (SM, but decreased the level of sphingosine-1-phosphate (S1P in cardiac muscle. Accordingly, the changes in sphingolipids content were accompanied by a lesser activity of neutral sphingomyelinase and without significant changes in ceramidases activity. Hyperthyroidism also induced activation of AMP-activated protein kinase (AMPK with subsequently increased expression of mitochondrial proteins: cytochrome c oxidase IV (COX IV, β-hydroxyacyl-CoA dehydrogenase (β-HAD, carnityne palmitoyltransferase I (CPT I and nuclear peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α. Conclusions: We conclude that prolonged T3 treatment increases sphingolipids metabolism which is reflected by higher concentration of SFA and CER in heart muscle. Furthermore, hyperthyroidism-induced increase in heart sphingomyelin (SM concentration might be one of the mechanisms underlying maintenance of CER at relatively low level by its conversion to SM together with decreased S1P content.

  6. Visual Evoked Potentials in Rett Syndrome

    J. Gordon Millichap


    Full Text Available Investigators from the Boston Children's Hospital recorded pattern-reversal visual evoked potentials (VEPs in Mecp2 heterozygous female mice and in 34 girls with Rett syndrome (RTT.

  7. Somatosensory evoked potentials in deaferentation pain

    Ilievska, Liljana; Gorgoska, E


    The aim of study was to examine how to the Somatosensory evoked potentials ( SEPs) are affected in patients with cerebrovascular thalamic lesions and to correlate the findings with sensory abnormalities.

  8. Subclinical hepatic encephalopathy: the diagnostic value of evoked potentials.

    Kullmann, F; Hollerbach, S; Holstege, A; Schölmerich, J


    Brainstem auditory (BAEPs) and somatosensory evoked potentials (SEPs) have been shown to be useful in detecting brainstem or cortical dysfunction in neurological diseases and in combination with other methods to diagnose brain death (37,38). These neurophysiological methods are simple and easy to perform. BAEPs and SEPs can even be easily recorded in intensive care units and guarantee a standardized examination. Moreover, these methods require no extensive patient cooperation and are not heavily influenced by learning effects. The role of BAEPs in the evaluation and diagnosis of hepatic encephalopathy is not clear. BAEPs are obviously strongly influenced by the etiology of liver disease and are normal in viral hepatitis, but prolonged in alcoholic liver disease, Wilson's disease or in hepatic coma (8,12). Unfortunately, BAEPs were not compared to psychometric tests. There was no clear-cut differentiation between various hepatic encephalopathy-gradings. At present, the use of BAEPs in the detection of subclinical hepatic encephalopathy cannot be recommended, whereas in comatose patients BAEPs can be useful as a prognostic marker and for follow-up examinations (12). Recently, Pozessere et al. (12) examined 13 comatose patients with advanced coma stages (Glasgow coma scale 5-10) and recorded unspecific changes in their EEG tracings. In all cases of hepatic coma and in one intoxicated patient they found prolongation of interpeak latencies. In addition, in this small study the interpeak latencies correlated well with the clinical outcome of the patients. Only two studies were performed using SEPs to detect neurophysiological alterations in hepatic encephalopathy (32,33). The design as well as the results of these studies are quite different. Despite the small number of patients (n = 10), the prolongation of late components in 50% of patients with hepatic encephalopathy stage 0 could be a promising result (32). The value of SEPs in detecting subclinical hepatic


    管宇宙; 崔丽英; 汤晓芙; 李本红; 杜华


    Objective. To study the features and mechanism of the cerebral evoked potentials by repetitive stimulation of calf muscle in Duchenne muscular dystrophy (DMD) patients with obvious muscular dystrophy and psuedohypertrophy. Methods. Cerebral evoked potentials by stimulation of calf muscles and somatusensory evoked potentials(SEPs) by the stimulation of posterior tibial nerves at ankle were measured in 10 patients with DMD and 10 norreal controls matched with gender and age. The intensity of the magnetic stimulation was at 30% of maximal output (2. 1 Tesla, MagPro magnetic stimulator, Dantec) and the frequency was 1 Hz. The low intensity of magnet-ic stimulation was just sufficient to produce a contraction of the muscle belly underneath the coil. Recording electrode was placed at 2 cm posterior to the Cz, reference to Fpz. The latencies of N33, P38, N48 and P55 and ampli-tude (P38 - N48) were recorded. SEPs were recorded by routine methods. Results. In normal subjects, the amphtudes of cerebral evoked potentials by magnetic stimulation of calf mus-cle was 40% lower than that by electrical stimulation of the posterior tibial nerves at ankle. The latency of P38 was 2. 9 ± 2. 1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients, P38 latency from magnetic stimulation was remarkably prolonged ( P < 0. 01), and in 4 patients, there was no remarkable response. SEPs evoked by electrical stimulation were normal in all of the patients. Conclusion. DMD is an available model for the study of mechanism of cerebral evoked potentials by magnetic stimulating muscle. We can conclude that the responses from magnetic stimulation were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by stimulating dystrophic and psedohypertrophic muscle.

  10. Prolonged abulia following putaminal hemorrhage.

    Nagaratnam, N; Fanella, S; Gopinath, S; Goodwin, A


    Abulia, akinetic mutism, and other conditions causing reduced activity and slowness are a continuum of severity of behavior. Unilateral lesions usually cause transient symptoms. This article describes a patient with prolonged abulia lasting 12 weeks after aspontaneous left putaminal hemorrhage. He developed seizures that could be a contributing factor. The pathophysiologic mechanisms are discussed. PMID:17903806

  11. Physiology Of Prolonged Bed Rest

    Greenleaf, John E.


    Report describes physiological effects of prolonged bed rest. Rest for periods of 24 hours or longer deconditions body to some extent; healing proceeds simultaneously with deconditioning. Report provides details on shifts in fluid electrolytes and loss of lean body mass, which comprises everything in body besides fat - that is, water, muscle, and bone. Based on published research.

  12. Prolongations of Geometric Overdetermined Systems

    Branson, Thomas; Cap, Andreas; Eastwood, Michael; Gover, Rod


    We show that a wide class of geometrically defined overdetermined semilinear partial differential equations may be explicitly prolonged to obtain closed systems. As a consequence, in the case of linear equations we extract sharp bounds on the dimension of the solution space.

  13. Genetic influence on prolonged gestation

    Laursen, Maja; Bille, Camilla; Olesen, Annette Wind;


    twin pairs, which indicates genetic effects. Biometric modeling suggested that genetic factors account for 23% to 30% of the liability to prolonged gestation. The difference in concordance rate between monozygotic and dizygotic male twin pairs was small, and the best fitting model indicated no genetic...

  14. The Analgesic Effect of Oxytocin in Humans: A Double-Blind, Placebo-Controlled Cross-Over Study Using Laser-Evoked Potentials.

    Paloyelis, Y; Krahé, C; Maltezos, S; Williams, S C; Howard, M A; Fotopoulou, A


    Oxytocin is a neuropeptide regulating social-affiliative and reproductive behaviour in mammals. Despite robust preclinical evidence for the antinociceptive effects and mechanisms of action of exogenous oxytocin, human studies have produced mixed results regarding the analgesic role of oxytocin and are yet to show a specific modulation of neural processes involved in pain perception. In the present study, we investigated the analgesic effects of 40 IU of intranasal oxytocin in 13 healthy male volunteers using a double-blind, placebo-controlled, cross-over design and brief radiant heat pulses generated by an infrared laser that selectively activate Aδ- and C-fibre nerve endings in the epidermis, at the same time as recording the ensuing laser-evoked potentials (LEPs). We predicted that oxytocin would reduce subjective pain ratings and attenuate the amplitude of the N1, N2 and P2 components. We observed that oxytocin attenuated perceived pain intensity and the local peak amplitude of the N1 and N2 (but not of P2) LEPs, and increased the latency of the N2 component. Importantly, for the first time, the present study reports an association between the analgesic effect of oxytocin (reduction in subjective pain ratings) and the oxytocin-induced modulation of cortical activity after noxious stimulation (attenuation of the N2 LEP). These effects indicate that oxytocin modulates neural processes contributing to pain perception. The present study reports preliminary evidence that is consistent with electrophysiological studies in rodents showing that oxytocin specifically modulates Aδ/C-fibre nociceptive afferent signalling at the spinal level and provides further specificity to evidence obtained in humans indicating that oxytocin may be modulating pain experience by modulating activity in the cortical areas involved in pain processing. PMID:26660859

  15. Prolonged fever after Infliximab infusion

    Jennifer; Katz; Michael; Frank


    Pharmacologic management for ulcerative colitis (UC) has recently been expanded to include antitumor necrosis factor (TNF) therapy for severe disease. Infliximab, a chimeric monoclonal antibody directed again TNF α was first tested in patients with Crohn’s disease. In addition to serious infections, malignancy, drug induced lupus and other autoimmune diseases, serum sickness-like reactions, neurological disease, and infusion reactions further complicate the use of Infliximab. We report a case of prolonged fever after Infliximab infusion to treat steroid refractory UC.

  16. Slow changes in Ca2(+) cause prolonged release from GABAergic retinal amacrine cells.

    Eggers, Erika D; Klein, Justin S; Moore-Dotson, Johnnie M


    The timing of neurotransmitter release from neurons can be modulated by many presynaptic mechanisms. The retina uses synaptic ribbons to mediate slow graded glutamate release from bipolar cells that carry photoreceptor inputs. However, many inhibitory amacrine cells, which modulate bipolar cell output, spike and do not have ribbons for graded release. Despite this, slow glutamate release from bipolar cells is modulated by slow GABAergic inputs that shorten the output of bipolar cells, changing the timing of visual signaling. The time course of light-evoked inhibition is slow due to a combination of receptor properties and prolonged neurotransmitter release. However, the light-evoked release of GABA requires activation of neurons upstream from the amacrine cells, so it is possible that prolonged release is due to slow amacrine cell activation, rather than slow inherent release properties of the amacrine cells. To test this idea, we directly activated primarily action potential-dependent amacrine cell inputs to bipolar cells with electrical stimulation. We found that the decay of GABAC receptor-mediated electrically evoked inhibitory currents was significantly longer than would be predicted by GABAC receptor kinetics, and GABA release, estimated by deconvolution analysis, was inherently slow. Release became more transient after increasing slow Ca(2+) buffering or blocking prolonged L-type Ca(2+) channels and Ca(2+) release from intracellular stores. Our results suggest that GABAergic amacrine cells have a prolonged buildup of Ca(2+) in their terminals that causes slow, asynchronous release. This could be a mechanism of matching the time course of amacrine cell inhibition to bipolar cell glutamate release. PMID:23657284

  17. Effect of cerebral lymphatic block on cerebral morphology and cortical evoked potential in rats

    Zuoli Xia; Baoling Sun; Mingfeng Yang; Dongmei Hu; Tong Zhao; Jingzhong Niu


    . Morphological changes of the brain and alterations of latency of cortical evoked potential were detected on the 1st ,2nd 3rd ,5th ,7th ,10th and 15th .days after operation under general,light microscope and electronic microscope observations.MAIN OUTCOME MEASURES:①Cerebral morphological changes;②latent changes of cortical evoked potential.RESULTS:A total of 63 rats were involved in the final analysis.①Cerebral morphological changes:General observation showed that,for cerebral lymphatic block rats,the surface of brain was pale and full,and cerebral gyrus was wide and flattened sulci after cerebral lymphatic block; and cerebral tissue space prolongation,increased interstitial fluid, neuronal degeneration and necrosis,diffused phagocytes and satellitosis were observed under light microscope.Neuronal swell and necrosis,gilal cell swell,apparent subcellular changes such as mitochondron were observed under electronic microscope. ②Latent changes of cortical evoked potential:As compared with sham-operation control group.1atency of cortical evoked potential in cerebral lymphatic blockage group prolonged on the 5th day and 7th day after cerebral lymphatic block[(6.28±0.23),(6.97±0.35)ms;(6.23±0.22),(7.12±0.20)ms;P<0.01].CONCLUSION:①Cerebral lymphatic block plays an important role in cerebral morphology,and may result in abnormaliy of sensitive impulse conduction and prolong latency of cortical evoked potential.②Examination of cortical evoked potential is easy and convenient,so it is regarded as a key index for lymphatic disturbed cerebral injury.

  18. Wiener kernel analysis of a noise-evoked otoacoustic emission

    van Dijk, P; Maat, A; Wit, H P


    In one specimen of the frog species, Rana esculenta, the following were measured: (1) a spontaneous otoacoustic emission; (2) a click-evoked otoacoustic emissions; and (3) a noise evoked otoacoustic emission. From the noise evoked emission response, a first-and a second-order Wiener kernel and the f

  19. Thought-evoking approaches in engineering problems


    In creating the value-added product in not distant future, it is necessary and inevitable to establish a holistic and though-evoking approach to the engineering problem, which should be at least associated with the inter-disciplinary knowledge and thought processes across the whole engineering spheres. It is furthermore desirable to integrate it with trans-disciplinary aspects ranging from manufacturing culture, through liberal-arts engineering, and industrial sociology.   The thought-evoking approach can be exemplified and typified by representative engineering problems: unveiling essential features in ‘Tangential Force Ratio and Interface Pressure’, prototype development for ‘Bio-mimetic Needle’ and application of ‘Water-jet Machining to Artificial Hip Joint’, product innovation in ‘Heat Sink for Computer’, application of ‘Graph Theory’ to similarity evaluation of production systems, leverage among reciprocity attributes in ‘Industrial and Engineering Designs for Machine Enclosure’,...

  20. Corticospinal tract conduction block results in the prolongation of central motor conduction time in compressive cervical myelopathy

    Nakanishi, Kazuyoshi; Tanaka, Nobuhiro; Fujiwara, Yasushi; Kamei, Naosuke; Ochi, Mitsuo


    Objective: The objective of this study was to analyze corticospinal function in patients with compressive cervical myelopathy and to elucidate the mechanism underlying its prolonged central motor conduction time (CMCT). Methods: Motor evoked potentials following transcranial magnetic stimulation (TMS) and peripheral conduction time in the ulnar and tibial nerves following electrical stimulation were measured from the abductor digiti minimi (ADM) and abductor hallucis (AH) muscles in 24 patien...

  1. Neuroimaging Evidence of Altered Fronto-Cortical and Striatal Function after Prolonged Cocaine Self-Administration in the Rat

    Gozzi, Alessandro; Tessari, Michela; Dacome, Lisa; Agosta, Federica; Lepore, Stefano; Lanzoni, Anna; Cristofori, Patrizia; Merlo Pich, Emilio; Corsi, Mauro; Bifone, Angelo


    Abstract Cocaine addiction is often modeled in experimental paradigms where rodents learn to self-administer the drug. However, the extent to which these models replicate the functional alterations observed in clinical neuroimaging studies of cocaine addiction remains unknown. We used Magnetic Resonance Imaging (MRI) to assess basal and evoked brain function in rats subjected to a prolonged, extended-access cocaine self-administration scheme. Specifically, we measured basal cere...

  2. Visual evoked potentials in the horse

    Ström, L.; Ekesten, B.


    Background Electrical potentials generated in the central nervous system in response to brief visual stimuli, flash visual evoked potentials (FVEPs), can be recorded non-invasively over the occipital cortex. FVEPs are used clinically in human medicine and also experimentally in a number of animal species, but the method has not yet been evaluated in the horse. The method would potentially allow the ophthalmologist and equine clinician to evaluate visual impairment caused by disorders affectin...

  3. Cervicothoracic Multisegmental Transpinal Evoked Potentials in Humans

    Einhorn, Jonathan; Li, Alan; Hazan, Royi; Knikou, Maria


    The objectives of this study were to establish the neurophysiological properties of the transpinal evoked potentials (TEPs) following transcutaneous electric stimulation of the spine (tsESS) over the cervicothoracic region, changes in the amplitude of the TEPs preceded by median nerve stimulation at group I threshold, and the effects of tsESS on the flexor carpi radialis (FCR) H-reflex in thirteen healthy human subjects while seated. Two re-usable self-adhering electrodes, connected to functi...

  4. Brainstem evoked potentials in panic disorder.

    Knott, V J; Bakish, D; Barkley, J.


    Patient reports and laboratory tests support the notion that panic attacks are generated by stimulation of brainstem nuclei. Scalp-recorded brainstem auditory evoked potentials may serve as a unique measurement strategy for the noninvasive assessment of the role of brainstem functioning in panic disorder. Ipsilateral and contralateral BSAEP recordings were examined in response to separate left and right ear click stimulation in 28 patients with a diagnosis of panic disorder and in 18 normal c...

  5. Somatosensory evoked potentials in amyotrophic lateral sclerosis.

    Cosi, V; Poloni, M.; Mazzini, L.; Callieco, R.


    Forty five patients with amyotrophic lateral sclerosis were investigated, by means of somatosensory evoked potentials, in order to detect the presence of subclinical sensory changes. Cervical SEPs from the median nerve and cortical SEPs from the median and tibial nerve were recorded, showing a delay of N13 and subsequent components; the latency of the first constant cortical potential was also increased in many patients. Only the SEPs from the tibial nerve showed a decrease of amplitude. Thes...


    Balasubramanian Thiagarajan


    Full Text Available Brain stem evoked response audiometry (BERA is a useful objective assessment of hearing. Major advantage of this procedure is its ability to test even infants in whom conventional audiometry may not be useful. This investigation can be used as a screening test for deafness in high risk infants. Early diagnosis and rehabilitation will reduce disability in these children. This article attempts to review the published literature on this subject.

  7. Prolonged QT interval in Rett syndrome

    ELLAWAY, C; Sholler, G; Leonard, H; Christodoulou, J.


    Rett syndrome is a severe neurodevelopmental disorder of unknown aetiology. A prolonged QT interval has been described previously in patients with Rett syndrome. To investigate QT prolongation and the presence of cardiac tachyarrhythmias in Rett syndrome electrocardiography and 24 hour Holter monitoring were performed prospectively in a cohort of 34 girls with Rett syndrome. The corrected QT value was prolonged in nine patients. Compared with a group of healthy controls of a...

  8. Methylxanthine-evoked perturbation of spontaneous and evoked activities in isolated newborn rat hippocampal networks.

    Ruangkittisakul, A; Sharopov, S; Kantor, C; Kuribayashi, J; Mildenberger, E; Luhmann, H J; Kilb, W; Ballanyi, K


    Treatment of apnea of prematurity with methylxanthines like caffeine, aminophylline or theophylline can evoke hippocampal seizures. However, it is unknown at which interstitial brain concentrations methylxanthines promote such neonatal seizures or interfere with physiological 'early network oscillations' (ENOs) that are considered as pivotal for maturation of hippocampal neural networks. We studied theophylline and caffeine effects on ENOs in CA3 neurons (CA3-ENOs) and CA3 electrical stimulation-evoked monosynaptic CA1 field potentials (CA1-FPs) in sliced and intact hippocampi, respectively, from 8 to 10-days-old rats. Submillimolar doses of theophylline and caffeine, blocking adenosine receptors and phosphodiesterase-4 (PDE4), did not affect CA3-ENOs, ENO-associated cytosolic Ca(2+) transients or CA1-FPs nor did they provoke seizure-like discharges. Low millimolar doses of theophylline (⩾1mM) or caffeine (⩾5mM), blocking GABAA and glycine receptors plus sarcoplasmic-endoplasmic reticulum Ca(2+) ATPase (SERCA)-type Ca(2+) ATPases, evoked seizure-like discharges with no indication of cytosolic Ca(2+) dysregulation. Inhibiting PDE4 with rolipram or glycine receptors with strychnine had no effect on CA3-ENOs and did not occlude seizure-like events as tested with theophylline. GABAA receptor blockade induced seizure-like discharges and occluded theophylline-evoked seizure-like discharges in the slices, but not in the intact hippocampi. In summary, submillimolar methylxanthine concentrations do not acutely affect spontaneous CA3-ENOs or electrically evoked synaptic activities and low millimolar doses are needed to evoke seizure-like discharges in isolated developing hippocampal neural networks. We conclude that mechanisms of methylxanthine-related seizure-like discharges do not involve SERCA inhibition-related neuronal Ca(2+) dysregulation, PDE4 blockade or adenosine and glycine receptor inhibition, whereas GABA(A) receptor blockade may contribute partially. PMID



    Objective. To study the features and mechanism of the cerebral evoked potentials by repetitive stimulation of calf muscle in Duchenne muscular dystrophy (DMD) patients with obvious muscular dystrophy and psuedohypertrophy. Methods. Cerebral evoked potentials by stimulation of calf muscles and somatosensory evoked potentials (SEPs) by the stimulation of posterior tibial nerves at ankle were measured in 10 patients with DMD and 10 normal controls matched with gender and age. The intensity of the magnetic stimulation was at 30% of maximal output (2.1 Tesla, MagPro magnetic stimulator, Dantec) and the frequency was 1 Hz. The low intensity of magnetic stimulation was just sufficient to produce a contraction of the muscle belly underneath the coil. Recording electrode was placed at 2 cm posterior to the Cz, reference to Fpz. The latencies of N33, P38, N48 and P55 and amplitude (P38- N48) were recorded. SEPs were recorded by routine methods. Results. In normal subjects, the amplitudes of cerebral evoked potentials by magnetic stimulation of calf muscle was 40% lower than that by electrical stimulation of the posterior tibial nerves at ankle. The latency of P38 was 2.9± 2.1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients, P38 latency from magnetic stimulation was remarkably prolonged (P<0.01), and in 4 patients, there was no remarkable response. SEPs evoked by electrical stimulation were normal in all of the patients.? Conclusion. DMD is an available model for the study of mechanism of cerebral evoked potentials by magnetic stimulating muscle. We can conclude that the responses from magnetic stimulation were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by stimulating dystrophic and psedohypertrophic muscle.

  10. Influence of prolonged optic flow stimuli on spontaneous activities of cat PMLS neurons


    Changes in neuronal spontaneous activities after prolonged optic flow stimulation (using the three basic flow modes: translation, radiation and rotation) were investigated by extracellular single-unit recording in cortical area PMLS of the cat. The results showed that the evoked responses decreased with the prolongation of visual stimuli, and the spontaneous activities usually dropped to a lower level after the stimuli were withdrawn. Generally, the reduction in spontaneous activities was larger after adaptation in the preferred direction than in the non-preferred direction. This difference was much pronounced to translation stimuli, but relatively insignificant to radiation and rotation. These points suggest that non-specific fatigue may act as the key factor in adaptation to simple translation, while some kinds of more complicated, direction-specific mechanism may be involved in adaptation to the complex optic flow patterns. In addition, PMLS may play an important role in perception and adaptation to complex motion and the relevant motion after-effects.

  11. Do ambient urban odors evoke basic emotions?



    Full Text Available Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman’s (Ekman et al., 1983 basic emotions happiness, surprise, anger, fear, sadness and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles / bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the skin conductance response and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles / bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

  12. Analysis of evoked lumbosacral potentials in man.

    Delbeke, J; McComas, A J; Kopec, S J


    Surface electrodes have been used to record potentials evoked in the lumbosacral region of 15 healthy volunteers after tibial nerve stimulation. By monitoring the M waves and H reflexes in the triceps surae muslces and by comparing the responses recorded over the roots with those over the lower cord, it was possible to identify the neural substrates responsible for several of the components in the responses. The findings are compared with those of previous studies in man and in other mammalian preparations. PMID:650237

  13. Somatosensory evoked response: application in neurology

    Carlos A. M. Guerreiro


    Full Text Available One technique used for short-latency somatosensory evoked response (SER is described. SER following nerve stimulation is a unique non-invasive, clinical test used to evaluate the somatosensory pathways. It tests the physiological function of the median nerve, the brachial plexus, the C6-7 cervical roots, cervical spinal cord, the cuneate nuclei, the medial lemniscus, the thalamus, and the contralateral sensory cortex. It has been shown to be a reliable and useful clinical test partiicularly in multiple sclerosis and comatose patients. The promising technique of SER following peroneal nerve stimulation is mentioned.

  14. Extracellular alkaline-acid pH shifts evoked by iontophoresis of glutamate and aspartate in turtle cerebellum.

    Chesler, M; Rice, M E


    The effect of glutamate and aspartate iontophoresis on extracellular pH was investigated in the turtle cerebellum in vitro. Both amino acids produced a rapid alkaline transient, typically followed by a prolonged acidification. These responses could be evoked in all layers of the cerebellum. Transition from bicarbonate to N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered media amplified the pH shifts. Similar alkaline-acid transients could be evoked in the molecular layer by electrical stimulation of the parallel fibers or the ipsilateral peduncle, or by superfusion of glutamate or aspartate. However, no alkaline shifts were evoked in the granular layer by either parallel fiber or peduncle stimulation. In contrast, the iontophoretically induced alkaline shifts were largest in the granular layer. Compared with the stimulus-evoked alkalinizations, the iontophoretic alkaline shifts were relatively insensitive to Mn2+ or Cd2+. These data suggest that the activity-dependent alkalinization of brain extracellular space is generated by a bicarbonate-independent mechanism related to excitatory synaptic transmission. The results are consistent with a flux of hydrogen ions through cationic channels, but do not support a direct role for voltage-dependent Ca2+ channels. In view of the sensitivity of ion channels to changes in external pH, and the magnitude of the amino acid-induced pH shifts, these results indicate that extracellular pH could play an important modulatory role in excitatory synaptic transmission. PMID:1711651

  15. Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

    Huys, Raoul; Jirsa, Viktor K; Darokhan, Ziauddin; Valentiniene, Sonata; Roland, Per E


    by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point......Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced...... attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization is that it...

  16. Effect of sodium tungstate on visual evoked potentials in diabetic rats

    Bulut, Mehmet; Dönmez, Barış Özgür; Öztürk, Nihal; Başaranlar, Göksun; Kencebay Manas, Ceren; Derin, Narin; Özdemir, Semir


    AIM To evaluate the effect of sodium tungstate on visual evoked potentials (VEPs) in diabetic rats. METHODS Wistar rats were randomly divided into three groups as normal control, diabetic control and diabetic rats treated with sodium tungstate. Diabetes was induced by single intraperitoneal injection of streptozotocin (50 mg/kg). Sodium tungstate [40 mg/(kg·d)] was administered for 12wk and then VEPs were recorded. Additionally, thiobarbituric acid reactive substance (TBARS) levels were measured in brain tissues. RESULTS The latencies of P1, N1, P2, N2 and P3 waves were significantly prolonged in diabetic rats compared with control group. Diabetes mellitus caused an increase in the lipid peroxidation process that was accompanied by changes in VEPs. However, prolonged latencies of VEPs for all components returned to control levels in sodium tungstate-treated group. The treatment of sodium tungstate significantly decreased brain TBARS levels and depleted the prolonged latencies of VEP components compared with diabetic control group. CONCLUSION Sodium tungstate shows protective effects on visual pathway in diabetic rats, and it can be worthy of further study for potential use. PMID:27275420

  17. Cervical vestibular evoked myogenic potentials in children

    Alcione Botelho Pereira


    Full Text Available INTRODUCTION: Cervical vestibular evoked myogenic potential is a test used in neurotological examination. It verifies the integrity of vestibular function through a muscular response evoked by an acoustic stimulation which activates the saccular macula. Normal standards in adults have been established, however, there are few published data on the normal responses in children.OBJECTIVE: To establish normal standards for vestibular myogenic responses in children without neurotological complaints.METHODS: This study's design is a cohort with cross-sectional analysis. The sample consisted of 30 subjects, 15 females (50% and 15 males (50%.RESULTS: The age of the subjects ranged between 8 and 13 years, with a mean of 10.2 (± 1.7. P1 peak showed an average latency of 17.26 (± 1.78 ms and a mean amplitude of 49.34 (± 23.07 µV, and the N2 peak showed an average latency of 24.78 (± 2.18 ms and mean amplitude of 66.23 (± 36.18 µV. P1-N2 mean amplitude was 115.6 (± 55.7 µV. There were no statistically significant differences when comparing by gender or by laterality.CONCLUSION: We established normal values of cervical myogenic vestibular responses in children between 8 and 13 years without neurotological complaints.

  18. Speech Evoked Auditory Brainstem Response in Stuttering

    Ali Akbar Tahaei


    Full Text Available Auditory processing deficits have been hypothesized as an underlying mechanism for stuttering. Previous studies have demonstrated abnormal responses in subjects with persistent developmental stuttering (PDS at the higher level of the central auditory system using speech stimuli. Recently, the potential usefulness of speech evoked auditory brainstem responses in central auditory processing disorders has been emphasized. The current study used the speech evoked ABR to investigate the hypothesis that subjects with PDS have specific auditory perceptual dysfunction. Objectives. To determine whether brainstem responses to speech stimuli differ between PDS subjects and normal fluent speakers. Methods. Twenty-five subjects with PDS participated in this study. The speech-ABRs were elicited by the 5-formant synthesized syllable/da/, with duration of 40 ms. Results. There were significant group differences for the onset and offset transient peaks. Subjects with PDS had longer latencies for the onset and offset peaks relative to the control group. Conclusions. Subjects with PDS showed a deficient neural timing in the early stages of the auditory pathway consistent with temporal processing deficits and their abnormal timing may underlie to their disfluency.

  19. Inferring Evoked and Consideration Set from Scanner Data

    Wirawan Dony Dahana; Nozomi Nakajima


    Evoked and consideration set have been one of main research topics in marketing field for a long time. Using interview data, many studies have been conducted to investigate the nature of its content. However, only few studies tried to do so by using consumer purchase history. By modeling the process of evoked and consideration set formation, in this research we try to elicit consumer evoked set from scanner data. Some managerial implications for marketing decisions derived from the informatio...

  20. Licence prolongations of US nuclear power plants

    Licences of US nuclear reactors were initially attributed for a 40 years duration. However, the vast majority of the reactors can benefit of a licence prolongation for a period of 20 years maximum. This article recalls first the procedure to follow for the licence prolongation demands (safety analysis, components aging, environmental impact statement), and then it makes a status of the accepted prolongations, of the demands under examination, and of the demands that should be presented in the next 5 years. (J.S.)

  1. Quality of drug label information on QT interval prolongation

    Warnier, Miriam J; Holtkamp, Frank A; Rutten, Frans H;


    -prolongation'/'QT-prolongation') and the advice on cautionary measures pertaining to QT-prolongation in the label were examined, as well as their association. RESULTS: Of the 175 screened products, 44 contained information on QT in the SPC ('no QT-prolongation': 23%, 'unclear drug-QT association': 43%, 'possibly QT-prolongation': 16...

  2. Prenatal risk indicators of a prolonged pregnancy

    Olesen, Annette Wind; Westergaard, Jes Grabow; Olsen, Jørn


    . Statistical analyses were done using logistic regression. RESULTS: Women with a pre-pregnancy body mass index of 25 kg/m2 or more had a high risk of prolonged pregnancy. If the pre-pregnancy body mass index was 35 kg/m2 or more the odds ratio was 1.52 (95% CI 1.28-1.82). Nulliparity also increased the risk of......BACKGROUND: Few prenatal risk factors of prolonged pregnancy, a pregnancy of 42 weeks or more, are known. The objective was to examine whether sociodemographic, reproductive, toxicologic, or medical health conditions were associated with the risk of prolonged pregnancy. METHODS: Data from the...... prolonged pregnancy (OR (95% CI) = 1.35 (1.27-1.44)). CONCLUSIONS: The risk of post-term delivery was high in women with a pre-pregnancy body mass index of 25 kg/m2 or more, and in nulliparous women....

  3. Music evokes vicarious emotions in listeners.

    Kawakami, Ai; Furukawa, Kiyoshi; Okanoya, Kazuo


    Why do we listen to sad music? We seek to answer this question using a psychological approach. It is possible to distinguish perceived emotions from those that are experienced. Therefore, we hypothesized that, although sad music is perceived as sad, listeners actually feel (experience) pleasant emotions concurrent with sadness. This hypothesis was supported, which led us to question whether sadness in the context of art is truly an unpleasant emotion. While experiencing sadness may be unpleasant, it may also be somewhat pleasant when experienced in the context of art, for example, when listening to sad music. We consider musically evoked emotion vicarious, as we are not threatened when we experience it, in the way that we can be during the course of experiencing emotion in daily life. When we listen to sad music, we experience vicarious sadness. In this review, we propose two sides to sadness by suggesting vicarious emotion. PMID:24910621

  4. Music evokes vicarious emotions in listeners

    Ai eKawakami


    Full Text Available Why do we listen to sad music? We seek to answer this question using a psychological approach. It is possible to distinguish perceived emotions from those that are experienced. Therefore, we hypothesized that, although sad music is perceived as sad, listeners actually feel (experience pleasant emotions concurrent with sadness. This hypothesis was supported, which led us to question whether sadness in the context of art is truly an unpleasant emotion. While experiencing sadness may be unpleasant, it may also be somewhat pleasant when experienced in the context of art, for example, when listening to sad music. We consider musically evoked emotion vicarious, as we are not threatened when we experience it, in the way that we can be during the course of experiencing emotion in daily life. When we listen to sad music, we experience vicarious sadness. In this review, we propose two sides to sadness by suggesting vicarious emotion.


    A. A. Sazgar


    Full Text Available It has been shown recently that loud clicks evoke myogenic potentials in the tonically contracting sternocleidomastoid muscles. Studies have suggested that these potentials are of vestibular origin, especially of the saccule and inferior vestibular nerve. A pilot study was undertaken in our hospital to record vestibular evoked myogenic potentials (VEMP for the first time in Iran. Eighteen healthy volunteers (32 ears without history of otologic or vestibular disorders were subjected to the VEMP test. Twenty-one patients (26 ears with unilateral (6 patients and bilateral (5 patients high frequency sensorineural hearing loss with unknown etiology, acoustic neuroma (1 patient, Meniere’s disease (4 patients and unilateral low frequency sensorineural hearing loss without vestibular complaint (5 patients were also enrolled in this study. VEMP response to clicks was obtained from 84.4% of ears of healthy subjects. These subjects demonstrated short latency waves to click stimuli during tonic neck flexor activation. Mean latencies of first positive (p13 and first negative (n23 potentials in healthy subjects were 12.45 ± 1.9 ms and 20.8 ± 3.5 ms, respectively. Median latencies of these two potentials were 12.1 and 19.3 ms, respectively. We could record VEMP in 5 patients with unilateral and all patients with high and low frequency sensorineural hearing loss without vestibular complaint. In the patient with acoustic neuroma VEMP was absent on the affected side. This technique may offer a new method to evaluate otolith and sacculocollic pathways in human.

  6. Somatosensory evoked potentials by paraspinal stimulation in acute transverse myelitis.

    Murthy J


    Full Text Available Somatosensory evoked potentials by paraspinal stimulation were studied in 6 patients with acute transverse myelitis. In one patient in whom posterior tibial somatosensory evoked potentials were not recordable, a poorly formed response was seen with paraspinal stimulation. Slowing of conduction across the involved segment was seen in the remaining 5 patients and fairly correlated with the clinical localization.

  7. Somatosensory evoked potentials by paraspinal stimulation in acute transverse myelitis.

    Murthy J


    Somatosensory evoked potentials by paraspinal stimulation were studied in 6 patients with acute transverse myelitis. In one patient in whom posterior tibial somatosensory evoked potentials were not recordable, a poorly formed response was seen with paraspinal stimulation. Slowing of conduction across the involved segment was seen in the remaining 5 patients and fairly correlated with the clinical localization.

  8. Conditioning effect of transcranial magnetic stimulation evoking motor‐evoked potential on V‐wave response

    Grosprêtre, Sidney; Martin, Alain


    Abstract The aim of this study was to examine the collision responsible for the volitional V‐wave evoked by supramaximal electrical stimulation of the motor nerve during voluntary contraction. V‐wave was conditioned by transcranial magnetic stimulation (TMS) over the motor cortex at several inter‐stimuli intervals (ISI) during weak voluntary plantar flexions (n = 10) and at rest for flexor carpi radialis muscle (FCR; n = 6). Conditioning stimulations were induced by TMS with intensity eliciti...

  9. Abnormal visual-evoked potentials in leukemic children after cranial radiation

    Visual-evoked potentials (VEPs) were studied in 55 asymptomatic children with leukemia or solid tumors in remission in order to detect subclinical demyelination of the optic pathway after CNS prophylaxis. In group I (11 patients with ALL studied prospectively), VEP latency was increased in ten after cranial radiation (CR) as compared with previous values. Group II (18 patients with ALL in maintenance) and group III (16 patients with ALL off therapy) were studied retrospectively and VEP latency was found above normal limits in 33 and 31%, respectively. In group IV (four patients with solid tumors and six with leukemia, all of whom received no CR), VEP latency was normal despite periodical intrathecal methotrexate administrations to five of them. The authors conclude that CR determines a slowing of conduction on VEP test, probably due to demyelination of the optic pathway, in a high proportion of patients. The future clinical significance of these findings must be established throughout a prolonged follow-up period

  10. Postoperative changes in visual evoked potentials and cognitive function tests following sevoflurane anaesthesia.

    Iohom, G


    We tested the hypothesis that minor disturbance of the visual pathway persists following general anaesthesia even when clinical discharge criteria are met. To test this, we measured visual evoked potentials (VEPs) in 13 ASA I or II patients who did not receive any pre-anaesthetic medication and underwent sevoflurane anaesthesia. VEPs were recorded on four occasions, before anaesthesia and at 30, 60, and 90 min after emergence from anaesthesia. Patients completed visual analogue scales (VAS) for sedation and anxiety, a Trieger Dot Test (TDT) and a Digit Symbol Substitution Test (DSST) immediately before each VEP recording. These results were compared using Student\\'s t-test. P<0.05 was considered significant. VEP latency was prolonged (P<0.001) and amplitude diminished (P<0.05) at 30, 60, and 90 min after emergence from anaesthesia, when VAS scores for sedation and anxiety, TDT, and DSST had returned to pre-anaesthetic levels.

  11. Light-evoked hyperpolarization and silencing of neurons by conjugated polymers

    Feyen, Paul; Colombo, Elisabetta; Endeman, Duco; Nova, Mattia; Laudato, Lucia; Martino, Nicola; Antognazza, Maria Rosa; Lanzani, Guglielmo; Benfenati, Fabio; Ghezzi, Diego


    The ability to control and modulate the action potential firing in neurons represents a powerful tool for neuroscience research and clinical applications. While neuronal excitation has been achieved with many tools, including electrical and optical stimulation, hyperpolarization and neuronal inhibition are typically obtained through patch-clamp or optogenetic manipulations. Here we report the use of conjugated polymer films interfaced with neurons for inducing a light-mediated inhibition of their electrical activity. We show that prolonged illumination of the interface triggers a sustained hyperpolarization of the neuronal membrane that significantly reduces both spontaneous and evoked action potential firing. We demonstrate that the polymeric interface can be activated by either visible or infrared light and is capable of modulating neuronal activity in brain slices and explanted retinas. These findings prove the ability of conjugated polymers to tune neuronal firing and suggest their potential application for the in-vivo modulation of neuronal activity.

  12. Early changes of auditory brain stem evoked response after radiotherapy for nasopharyngeal carcinoma - a prospective study

    Lau, S.K.; Wei, W.I.; Sham, J.S.T.; Choy, D.T.K.; Hui, Y. (Queen Mary Hospital, Hong Kong (Hong Kong))


    A prospective study of the effect of radiotherapy for nasopharyngeal carcinoma on hearing was carried out on 49 patients who had pure tone, impedance audiometry and auditory brain stem evoked response (ABR) recordings before, immediately, three, six and 12 months after radiotherapy. Fourteen patients complained of intermittent tinnitus after radiotherapy. We found that 11 initially normal ears of nine patients developed a middle ear effusion, three to six months after radiotherapy. There was mixed sensorineural and conductive hearing impairment after radiotherapy. Persistent impairment of ABR was detected immediately after completion of radiotherapy. The waves I-III and I-V interpeak latency intervals were significantly prolonged one year after radiotherapy. The study shows that radiotherapy for nasopharyngeal carcinoma impairs hearing by acting on the middle ear, the cochlea and the brain stem auditory pathway. (Author).

  13. Changes of paired-pulse evoked responses during the development of epileptic activity in the hippocampus

    Zhou-yan FENG; Xiao-jing ZHENG; Cong TIAN; Yang WANG; Hao-yu XING


    Dysfunction of inhibitory synaptic transmission can destroy the balance between excitatory and inhibitory synaptic inputs in neurons,thereby inducing epileptic activity.The aim of the paper is to investigate the effects of successive excitatory inputs on the epileptic activity induced in the absence of inhibitions.Paired-pulse orthodromic and antidromic stimulations were used to test the changes in the evoked responses in the hippocampus.Picrotoxin (PTX),y-aminobutyric acid (GABA) type A (GABAA) receptor antagonist,was added to block the inhibitory synaptic transmission and to establish the epileptic model.Extracellular evoked population spike (PS) was recorded in the CA1 region of the hippocampus.The results showed that the application of PTX induced a biphasic change in the paired-pulse ratio of PS amplitude.A short latency increase of the second PS (PS2) was later followed by a reappearance of PS2 depression.This type of depression was observed in both orthodromic and antidromic paired-pulse responses,whereas the GABAergic PS2 depression [called paired-pulse depression (PPD)] during baseline recordings only appeared in orthodromic-evoked responses.In addition,the depression duration at approximately 100 ms was consistent with a relative silent period observed within spontaneous burst discharges induced by prolonged application of PTX.In conclusion,the neurons may ignore the excitatory inputs and intrinsically generate bursts during epileptic activity.The depolarization block could be the mechanisms underlying the PPD in the absence of GABAA inhibitions.The distinct neuronal responses to stimulations during different epileptic stages may implicate the different antiepileptic effects of electrical stimulation.

  14. Event-related evoked potentials in chronic respiratory encephalopathy

    A R Al Tahan


    Full Text Available A R Al Tahan1, R Zaidan1, S Jones2, A Husain3, A Mobeireek1, A Bahammam11Department of Medicine, 3Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 2Department of Neurophysiology, Institute of Neurology, London, UKBackground: Cognitive event-related potential (P300 is an index of cognitive processing time. It was found to be prolonged in dementia, renal, and hepatic encephalopathies, but was not extensively assessed in respiratory failure.Objective: To evaluate P300 changes in patients with respiratory failure, and especially those with mild or subclinical hypoxic–hypercapnic encephalopathy.Methods: Auditory event-related evoked potential P300 latency was measured using an oddball paradigm in patients with respiratory failure due to any cause (partial pressure of oxygen in arterial blood (PO2 should be 75 mm/Hg or less. Apart from blood gases measurement, patients underwent the Mini-Mental State Examination (MMSE. Patient performances were compared with that of matched normal control. Patients were admitted into the study from outpatient clinics and wards at King Khalid University Hospital and Sahara Hospital.Results: Thirty-four patients (12 women, 22 men were admitted to the study. Ages ranged from 19–67 years with a mean of 46.1 years. Respiratory failure was severe or very severe in 11 patients (33%, and mild or moderate in the rest (66%. Mean value for PO2 and partial pressure of carbon dioxide in arterial blood (PCO2 were 63.7 and 45.2 mm/Hg, respectively. pH mean was 7.4 and O2 saturation was 90.7%. P300 latency ranged from 218 to 393 milliseconds, with a mean of 338.4 milliseconds. In comparison with control (309.9 milliseconds, there was a significant difference (P = 0.007. P300 amplitude differences were not significant. No significant difference in MMSE was noted between mild and severe respiratory failure. Results of detailed neuropsychological assessment were clearly abnormal but were

  15. Cervicothoracic multisegmental transpinal evoked potentials in humans.

    Jonathan Einhorn

    Full Text Available The objectives of this study were to establish the neurophysiological properties of the transpinal evoked potentials (TEPs following transcutaneous electric stimulation of the spine (tsESS over the cervicothoracic region, changes in the amplitude of the TEPs preceded by median nerve stimulation at group I threshold, and the effects of tsESS on the flexor carpi radialis (FCR H-reflex in thirteen healthy human subjects while seated. Two re-usable self-adhering electrodes, connected to function as one electrode (cathode, were placed bilaterally on the clavicles. A re-usable electrode (anode was placed on the cervicothoracic region covering from Cervical 4-Thoracic 2 and held under constant pressure throughout the experiment. TEPs were recorded bilaterally from major arm muscles with subjects seated at stimulation frequencies of 1.0, 0.5, 0.33, 0.2, 0.125, and 0.1 Hz, and upon double tsESS pulses delivered at an inter-stimulus interval of 40 ms. TEPs from the arm muscles were also recorded following median nerve stimulation at the conditioning-test (C-T intervals of 2, 3, 5, 8, and 10 ms. The FCR H-reflex was evoked and recorded according to conventional methods following double median nerve pulses at 40 ms, and was also conditioned by tsESS at C-T intervals that ranged from -10 to +50 ms. The arm TEPs amplitude was not decreased at low-stimulation frequencies and upon double tsESS pulses in all but one subject. Ipsilateral and contralateral arm TEPs were facilitated following ipsilateral median nerve stimulation, while the FCR H-reflex was depressed by double pulses and following tsESS at short and long C-T intervals. Non-invasive transpinal stimulation can be used as a therapeutic modality to decrease spinal reflex hyper-excitability in neurological disorders and when combined with peripheral nerve stimulation to potentiate spinal output.

  16. Chronic high-NaCl intake prolongs the cardiorenal responses to central N/OFQ and produces regional changes in the endogenous brain NOP receptor system

    Wainford, Richard D; Kapusta, Daniel R.


    Intracerebroventricular nociceptin/orphanin FQ (N/OFQ) produces cardiovascular depressor, diuretic, and renal sympathoinhibitory responses in conscious rats. These studies examined how a chronic high-NaCl intake alters these peptide-evoked responses and the activity of the endogenous central N/OFQ peptide (NOP) receptor system. In normotensive Sprague-Dawley rats fed a chronic (3-wk) high (8%)-NaCl diet, intracerebroventricular N/OFQ (5.5 nmol) produced prolonged bradycardic, hypotensive, and...

  17. Surface electrical stimulation to evoke referred sensation.

    Forst, Johanna C; Blok, Derek C; Slopsema, Julia P; Boss, John M; Heyboer, Lane A; Tobias, Carson M; Polasek, Katharine H


    Surface electrical stimulation (SES) is being investigated as a noninvasive method to evoke natural sensations distal to electrode location. This may improve treatment for phantom limb pain as well as provide an alternative method to deliver sensory feedback. The median and/or ulnar nerves of 35 subjects were stimulated at the elbow using surface electrodes. Strength-duration curves of hand sensation were found for each subject. All subjects experienced sensation in their hand, which was mostly described as a paresthesia-like sensation. The rheobase and chronaxie values were found to be lower for the median nerve than the ulnar nerve, with no significant difference between sexes. Repeated sessions with the same subject resulted in sufficient variability to suggest that recalculating the strength-duration curve for each electrode placement is necessary. Most of the recruitment curves in this study were generated with 28 to 36 data points. To quickly reproduce these curves with limited increase in error, we recommend 10 data points. Future studies will focus on obtaining different sensations using SES with the strength-duration curve defining the threshold of the effective parameter space. PMID:26348194

  18. Auditory evoked potential measurements in elasmobranchs

    Casper, Brandon; Mann, David


    Auditory evoked potentials (AEP) were first used to examine hearing in elasmobranchs by Corwin and Bullock in the late 1970s and early 1980s, marking the first time AEPs had been measured in fishes. Results of these experiments identified the regions of the ear and brain in which sound is processed, though no actual hearing thresholds were measured. Those initial experiments provided the ground work for future AEP experiments to measure fish hearing abilities in a manner that is much faster and more convenient than classical conditioning. Data will be presented on recent experiments in which AEPs were used to measure the hearing thresholds of two species of elasmobranchs: the nurse shark, Ginglymostoma cirratum, and the yellow stingray, Urobatis jamaicencis. Audiograms were analyzed and compared to previously published audiograms obtained using classical conditioning with results indicating that hearing thresholds were similar for the two methods. These data suggest that AEP testing is a viable option when measuring hearing in elasmobranchs and can increase the speed in which future hearing measurements can be obtained.

  19. Auditory evoked potential measurements with cetaceans

    Mann, David; Cook, Mandy; Bauer, Gordon; Fellner, Wendi; Wells, Randy


    Auditory evoked potentials (AEPs) allow researchers to measure the hearing abilities of animals that would be difficult or impossible to train for behavioral measurements of hearing. The hearing abilities of live-stranded cetaceans and wild dolphins can only be made with AEP techniques. In these situations, time with the animal is often restricted to an hour or less, and there is often little control over the acoustic environment in which the tests are performed. AEP measurements may be made while the animals are in air or in shallow pools. For cetaceans in air, sounds are typically presented with a suction cup jawphone. For cetaceans in water, sounds may be presented in a direct field (with the transducer located at some distance from the test subject) or with a jawphone. In each of these situations it is important to understand how thresholds derived from AEP measurements compare with behavioral hearing measurements. Examples of AEP measurements from wild and live-stranded cetaceans are presented to illustrate their usefulness and the constraints under which these measurements must be made. AEP measurements from bottlenose dolphins in air and in water are also compared with their behavioral audiograms.

  20. Mechanical Stimulation by Postnasal Drip Evokes Cough

    Iwata, Toshiyuki; Ito, Isao; Niimi, Akio; Ikegami, Koji; Marumo, Satoshi; Tanabe, Naoya; Nakaji, Hitoshi; Kanemitsu, Yoshihiro; Matsumoto, Hisako; Kamei, Junzo; Setou, Mitsutoshi; Mishima, Michiaki


    Cough affects all individuals at different times, and its economic burden is substantial. Despite these widespread adverse effects, cough research relies on animal models, which hampers our understanding of the fundamental cause of cough. Postnasal drip is speculated to be one of the most frequent causes of chronic cough; however, this is a matter of debate. Here we show that mechanical stimuli by postnasal drip cause chronic cough. We distinguished human cough from sneezes and expiration reflexes by airflow patterns. Cough and sneeze exhibited one-peak and two-peak patterns, respectively, in expiratory airflow, which were also confirmed by animal models of cough and sneeze. Transgenic mice with ciliary dyskinesia coughed substantially and showed postnasal drip in the pharynx; furthermore, their cough was completely inhibited by nasal airway blockade of postnasal drip. We successfully reproduced cough observed in these mice by injecting artificial postnasal drip in wild-type mice. These results demonstrated that mechanical stimulation by postnasal drip evoked cough. The findings of our study can therefore be used to develop new antitussive drugs that prevent the root cause of cough. PMID:26581078

  1. Mechanical Stimulation by Postnasal Drip Evokes Cough.

    Toshiyuki Iwata

    Full Text Available Cough affects all individuals at different times, and its economic burden is substantial. Despite these widespread adverse effects, cough research relies on animal models, which hampers our understanding of the fundamental cause of cough. Postnasal drip is speculated to be one of the most frequent causes of chronic cough; however, this is a matter of debate. Here we show that mechanical stimuli by postnasal drip cause chronic cough. We distinguished human cough from sneezes and expiration reflexes by airflow patterns. Cough and sneeze exhibited one-peak and two-peak patterns, respectively, in expiratory airflow, which were also confirmed by animal models of cough and sneeze. Transgenic mice with ciliary dyskinesia coughed substantially and showed postnasal drip in the pharynx; furthermore, their cough was completely inhibited by nasal airway blockade of postnasal drip. We successfully reproduced cough observed in these mice by injecting artificial postnasal drip in wild-type mice. These results demonstrated that mechanical stimulation by postnasal drip evoked cough. The findings of our study can therefore be used to develop new antitussive drugs that prevent the root cause of cough.


    Arrthy S, Vinodha R, Saravanan S


    Full Text Available Background and Objectives: Cranial neuropathy is one of the common late complications of Diabetes Mellitus(DM, including distal symmetric sensory polyneuropathy and peripheral neuropathy(PN. Though many studies support the involvement of Cranial nerves III, VI and VII in diabetic patients, little was known about the involvement of II & VIII nerve. The goal of this study was to evaluate the involvement of optic nerve and vestibulocochlear nerve using Visual Evoked potential (VEP and Brainstem Auditary Evoked Potential (BAEP. Methods: Forty patients with 8 to 12 years duration of type 2 DM in 40 to 60 years age group (Group1 were selected from diabetic outpatient department in Thanjavur medical college hospital and compared with control group (Group 2 who were normal subjects and was age and sex matched. Physical examination and laboratory investigations including fasting glucose, renal functions were done in addition to VEP & BAEP for all groups. P100 latency using VEP and bilateral inter-peak latency IPL I-III, IPL III-V & IPL I-V using BAEP was evaluated and and analyzed for the study group and control group. Result: VEP P100 latency and BAEP bilateral inter-peak latency IPL I-III, IPL III-V & IPL I-V were prolonged in the study group compared to control group. Conclusion: This study concluded the involvement of optic and vestibulocochlear nerve in type 2 DM as the latency was prolonged.

  3. Changes of evoked potential and expression of nestin in subventricular zones in rats after focal cerebral ischemia

    GAO Jie; WANG Yong-tang; WANG Li-li; ZENG Ling; WU Ya-min; SHAO Yang


    Objective:To study the characteristics of latency of somatosensory evoked potential (SEP)and motor evoked potential (MEP) and the expression of nestin in subventricular zones (SVZ) after persistent focal cerebral ischemia in rats. Methods: The model of cerebral ischemia in rats was made by middle cerebral artery occlusion (MCAO). All animals of ischemia were sacrificed after 12 h, 1 d, 3 d, 7 d,and 14 d to observe the changes of latency of SEP and MEP and to detect the expression of nestin, with an immunohistochemical approach. Results: The latencies of P1 (positive wave 1), N1 (negative wave 1) and P2 (positive wave 2) in SEP were significantly prolonged after MCAO. The latencies of N1 and N2 waves in MEP were postponed gradually and no statistical difference of latency of N1 wave was found in rats at 7d and 14 d after MCAO. The expression of nestin increased at 12 h, and showed a significant augmentation at 3 d and peaked at 7 d, then declined slightly at 14 d after MCAO. Conclusion: The cerebral ischemia prolonged the latency of EP waves and the expression of nestin was up-regulated and reached the peak at 7d, showing the ischemia induced the proliferation of nervous stem cells. The SEP and MEP may evaluate the proliferation in SVZ after brain ischemia.

  4. Underlying Etiologies of Prolonged Icterus in Neonates

    F. Mortazavi


    Full Text Available The purpose of this study was to determine underlying causes of prolonged neonatal icterus. Icterus or jaundice is an important common problem in neonatology. When this condition persists beyond 14 days, it is called prolonged or protracted neonatal icterus. Determining underlying causes of this problem is a pivotal step for management, because a delay in treatment may lead to serious complications or even death. In a prospective study, newborns with diagnosis of prolonged icterus were evaluated during a six-month period in Tabriz Children Teaching Hospital. Data regarding the past medical history, physical examination and appropriate laboratory and paraclinical investigations were gathered and accordingly, the underlying cause of jaundice was documented. One hundred newborns, 67 males and 33 females with a mean age of 21.5±4.5 days were enrolled. Breastfeeding, urinary tract infection, glucose 6-phosphate dehydrogenase deficiency and hypothyroidism were found as the main underlying causes in 75, 7, 7 and 4% of the cases. The exact etiology was unknown in 4% of newborns. ABO incompatibility, sepsis and Down syndrome were underlying etiologies in remaining three patients. Present study showed that the underlying causes of prolonged neonatal jaundice could be determined in majority of cases and breastfeeding is the most common one in this regard.

  5. Pudendal somatosensory evoked potentials in normal women

    Geraldo A. Cavalcanti


    Full Text Available OBJECTIVE: Somatosensory evoked potential (SSEP is an electrophysiological test used to evaluate sensory innervations in peripheral and central neuropathies. Pudendal SSEP has been studied in dysfunctions related to the lower urinary tract and pelvic floor. Although some authors have already described technical details pertaining to the method, the standardization and the influence of physiological variables in normative values have not yet been established, especially for women. The aim of the study was to describe normal values of the pudendal SSEP and to compare technical details with those described by other authors. MATERIALS AND METHODS: The clitoral sensory threshold and pudendal SSEP latency was accomplished in 38 normal volunteers. The results obtained from stimulation performed on each side of the clitoris were compared to ages, body mass index (BMI and number of pregnancies. RESULTS: The values of clitoral sensory threshold and P1 latency with clitoral left stimulation were respectively, 3.64 ± 1.01 mA and 37.68 ± 2.60 ms. Results obtained with clitoral right stimulation were 3.84 ± 1.53 mA and 37.42 ± 3.12 ms, respectively. There were no correlations between clitoral sensory threshold and P1 latency with age, BMI or height of the volunteers. A significant difference was found in P1 latency between nulliparous women and volunteers who had been previously submitted to cesarean section. CONCLUSIONS: The SSEP latency represents an accessible and reproducible method to investigate the afferent pathways from the genitourinary tract. These results could be used as normative values in studies involving genitourinary neuropathies in order to better clarify voiding and sexual dysfunctions in females.

  6. Baroreceptor activation attenuates attentional effects on pain-evoked potentials

    Gray, Marcus A.; Minati, Ludovico; Paoletti, Giulia; Critchley, Hugo D.


    Focused attention typically enhances neural nociceptive responses, reflected electroencephalographically as increased amplitude of pain-evoked event-related potentials (ERPs). Additionally, pain-evoked ERPs are attenuated by hypertension and baroreceptor activity, through as yet unclear mechanisms. There is indirect evidence that these two effects may interact, suggesting that baroreceptor-related modulation of nociception is more than a low-level gating phenomenon. To address this hypothesis...

  7. Click- and chirp-evoked human compound action potentials

    Chertoff, Mark; Lichtenhan, Jeffery; Willis, Marie


    In the experiments reported here, the amplitude and the latency of human compound action potentials (CAPs) evoked from a chirp stimulus are compared to those evoked from a traditional click stimulus. The chirp stimulus was created with a frequency sweep to compensate for basilar membrane traveling wave delay using the O-Chirp equations from Fobel and Dau [(2004). J. Acoust. Soc. Am. 116, 2213–2222] derived from otoacoustic emission data. Human cochlear traveling wave delay estimates were obta...

  8. Muscle synergies evoked by microstimulation are preferentially encoded during behavior

    Simon Alexander Overduin


    Full Text Available Electrical microstimulation studies provide some of the most direct evidence for the neural representation of muscle synergies. These synergies, i.e. coordinated activations of groups of muscles, have been proposed as building blocks for the construction of motor behaviors by the nervous system. Intraspinal or intracortical microstimulation has been shown to evoke muscle patterns that can be resolved into a small set of synergies similar to those seen in natural behavior. However, questions remain about the validity of microstimulation as a probe of neural function, particularly given the relatively long trains of supratheshold stimuli used in these studies. Here, we examined whether muscle synergies evoked during intracortical microstimulation in two rhesus macaques were similarly encoded by nearby motor cortical units during a purely voluntary behavior involving object reach, grasp, and carry movements. At each microstimulation site we identified the synergy most strongly evoked among those extracted from muscle patterns evoked over all microstimulation sites. For each cortical unit recorded at the same microstimulation site, we then identified the synergy most strongly encoded among those extracted from muscle patterns recorded during the voluntary behavior. We found that the synergy most strongly evoked at an intracortical microstimulation site matched the synergy most strongly encoded by proximal units more often than expected by chance. These results suggest a common neural substrate for microstimulation-evoked motor responses and for the generation of muscle patterns during natural behaviors.

  9. Visual evoked potentials in infants and children.

    Taylor, M J; McCulloch, D L


    Visual evoked potential (VEP) studies are of great value in a wide variety of pediatric patients, including those with disorders of the sensory visual pathway and those at risk for visual pathway damage. VEPs are simple, non-invasive, and are particularly appropriate for infants and young children who cannot communicate visual symptoms or cooperate for standard vision assessment. VEPs in pediatric patients have the following main purposes: (1) detecting lesions causing dysfunction of the sensory visual pathways (the VEP is a sensitive indicator of subclinical lesions and can be used to differentiate visual impairment from visual inattention in young infants); (2) confirming functional loss when disorders of the visual system are present; (3) quantifying visual impairment in patients with known visual disorders, accomplished either empirically by noting the severity of the VEP abnormality to flash and pattern stimuli or by visual acuity estimation studies (early quantification of vision loss allows referral to early intervention programs, which can ameliorate the long-term consequences of the disability); (4) monitoring patients who are at risk for visual complications either from diseases (such as hydrocephalus or neurofibromatosis) or as a complication of therapeutic intervention (e.g., neurosurgery, chemotherapy) to help detect and avoid long-term sequelae of such therapies on the developing nervous system; (5) establishing prognosis for visual and systemic recovery based on flash VEPs for specific pediatric disorders including perinatal asphyxia in full-term neonates, acute-onset cortical blindness, and, to a fair extent, in comatose children; and (6) in some cases, contributing to the differential diagnosis. Abnormalities of flash and/or pattern VEPs are generally nonspecific to the type of exact location of the lesion, except in distinguishing prefrom postchiasmal lesions. However, in certain conditions, such as the hereditary ataxias of childhood, VEP

  10. Severe bradycardia and prolonged hypotension in ciguatera.

    Chan, Thomas Yan Keung


    Ciguatera results when ciguatoxin-contaminated coral reef fish from tropical or subtropical waters are consumed. The clinical features that present in affected persons are mainly gastrointestinal, neurological, general, and much less commonly, cardiovascular. We report the case of a 50-year-old man who developed the characteristic combination of acute gastrointestinal and neurological symptoms after the consumption of an unidentified coral reef fish head. In addition to those symptoms, he developed dizziness, severe bradycardia (46 bpm) and prolonged hypotension, which required the administration of intravenous atropine and over three days of intravenous fluid replacement with dopamine infusion. Patients with ciguatera can develop severe bradycardia and prolonged hypotension. Physicians should recognise the possible cardiovascular complications of ciguatera and promptly initiate treatment with intravenous atropine, intravenous fluid replacement and inotropic therapy if such complications are observed. PMID:23665698

  11. The paradox of music-evoked sadness: an online survey.

    Liila Taruffi

    Full Text Available This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772. The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

  12. The paradox of music-evoked sadness: an online survey.

    Taruffi, Liila; Koelsch, Stefan


    This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life. PMID:25330315

  13. Prolonged grief: setting the research agenda

    Rita Rosner


    Full Text Available Background: Prolonged grief disorder is proposed for the International Classification of Diseases (ICD-11, though it was rejected as a diagnosis for DSM-5. Objective: This review outlines findings and defines important areas for future research viewed from a lifespan perspective. Results: The development and psychometric evaluation of measures for the new diagnosis is paramount, specifically for children and adolescents. Treatments need to be adapted for specific subgroups and research findings have to be disseminated into various professional settings.

  14. Prolonged Exposure: a Rapid Treatment for Phobias

    Watson, J. P.; Gaind, R.; Marks, I. M.


    Ten adult patients with long-standing specific phobias were treated by prolonged continuous exposure to their phobic objects in fantasy and reality without avoidance. All patients were greatly helped by four to five hours' treatment in two or three sessions, and all improved more after practice than after imaginal sessions. The treatment method is more economical and efficient than other methods described so far. PMID:5539135

  15. Gradient-prolongation commutativity and graph theory

    Musy, François; Nicolas, Laurent; Perrussel, Ronan


    6 pages International audience This Note gives conditions that must be imposed to algebraic multilevel discretizations involving at the same time nodal and edge elements so that a gradient-prolongation commutativity condition will be satisfied; this condition is very important, since it characterizes the gradients of coarse nodal functions in the coarse edge function space. They will be expressed using graph theory and they provide techniques to compute approximation bases at each level.

  16. Brain glycogen decreases during prolonged exercise

    Matsui, Takashi; Soya, Shingo; Okamoto, Masahiro; Ichitani, Yukio; Kawanaka, Kentaro; Soya, Hideaki


    Abstract Brain glycogen could be a critical energy source for brain activity when the glucose supply from the blood is inadequate (hypoglycaemia). Although untested, it is hypothesized that during prolonged exhaustive exercise that induces hypoglycaemia and muscular glycogen depletion, the resultant hypoglycaemia may cause a decrease in brain glycogen. Here, we tested this hypothesis and also investigated the possible involvement of brain monoamines with the reduced levels of brain glycogen. For this purpose, we exercised male Wistar rats on a treadmill for different durations (30–120 min) at moderate intensity (20 m min−1) and measured their brain glycogen levels using high-power microwave irradiation (10 kW). At the end of 30 and 60 min of running, the brain glycogen levels remained unchanged from resting levels, but liver and muscle glycogen decreased. After 120 min of running, the glycogen levels decreased significantly by ∼37–60% in five discrete brain loci (the cerebellum 60%, cortex 48%, hippocampus 43%, brainstem 37% and hypothalamus 34%) compared to those of the sedentary control. The brain glycogen levels in all five regions after running were positively correlated with the respective blood and brain glucose levels. Further, in the cortex, the levels of methoxyhydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA), potential involved in degradation of the brain glycogen, increased during prolonged exercise and negatively correlated with the glycogen levels. These results support the hypothesis that brain glycogen could decrease with prolonged exhaustive exercise. Increased monoamines together with hypoglycaemia should be associated with the development of decreased brain glycogen, suggesting a new clue towards the understanding of central fatigue during prolonged exercise. PMID:21521757

  17. Risk Modifiers for Concussion and Prolonged Recovery

    Scopaz, Kristen A.; Hatzenbuehler, John R.


    Context: Currently, no consensus exists for grading the severity of concussions. Identification of risk factors that may affect concussion risk and the likelihood of prolonged recovery can be of value to providers who manage concussion. Evidence Acquisition: Relevant studies were identified through MEDLINE (1996-2011) using the keywords concussion, postconcussive syndrome, and risk or risk factor. Targeted searches for specific risk factors were conducted with additional keywords, such as gen...

  18. Continued Maturation of the Click-Evoked Auditory Brainstem Response in Preschoolers

    Spitzer, Emily; White-Schwoch, Travis; Carr, Kali Woodruff; Skoe, Erika; Kraus, Nina


    Background Click-evoked auditory brainstem responses (ABRs) are a valuable tool for probing auditory system function and development. Although it has long been thought that the human auditory brainstem is fully mature by age 2 yr, recent evidence indicates a prolonged developmental trajectory. Purpose The purpose of this study was to determine the time course of ABR maturation in a preschool population and fill a gap in the knowledge of development. Research Design Using a cross-sectional design, we investigated the effect of age on absolute latencies, interwave latencies, and amplitudes (waves I, III, V) of the click-evoked ABR. Study Sample A total of 71 preschoolers (ages 3.12–4.99 yr) participated in the study. All had normal peripheral auditory function and IQ. Data Collection and Analysis ABRs to a rarefaction click stimulus presented at 31/sec and 80 dB SPL (73 dB nHL) were recorded monaurally using clinically-standard recording and filtering procedures while the participant sat watching a movie. Absolute latencies, interwave latencies, and amplitudes were then correlated to age. Results Developmental changes were restricted to absolute latencies. Wave V latency decreased significantly with age, whereas wave I and III latencies remained stable, even in this restricted age range. Conclusions The ABR does not remain static after age 2 yr, as seen by a systematic decrease in wave V latency between ages 3 and 5 yr. This finding suggests that the human brainstem has a continued developmental time course during the preschool years. Latency changes in the age 3–5 yr range should be considered when using ABRs as a metric of hearing health. PMID:25597458

  19. Multimodal evoked potentials in spinocerebellar ataxia types 1, 2, and 3

    Vijay Chandran


    Full Text Available Aims: Spinocerebellar ataxias (SCA are a clinically heterogeneous group of disorders that are characterized by ataxia and an autosomal dominant pattern of inheritance. The aim of our study was to describe the findings of evoked potentials (EPs among genetically proven SCA types 1, 2, and 3 and to additionally evaluate if EPs can be used to differentiate between them. Materials and Methods: Forty-three cases of genetically proven SCA (SCA1 = 19, SCA2 = 13, and SCA3 = 11 were evaluated with median somatosensory-EP (mSSEP, visual-EP (VEP, and brainstem auditory-evoked response (BAER by standard procedures and compared with normative laboratory data. An EP was considered abnormal if latency was prolonged (>mean + 3 standard deviation (SD of laboratory control data or the waveform was absent or poorly defined. The waves studied were as follows: mSSEP - N20, VEP - P100 and BAER - interpeak latency 1-3 and 3-5. Results: EPs were abnormal in at least one modality in 90.9% of patients. The most common abnormality was of BAER (86.1% followed by VEP (34.9% and mSSEP (30.2%. The degree of abnormality in VEP, mSSEP, and BAER among patients with SCA1 was 42.1, 41.2, and 73.3%, respectively; among patients with SCA2 was 38.5, 27.3, and 100%, respectively; and among patients with SCA3 was 18.2, 37.5, and 88.9%, respectively. The differences between the subgroups of SCAs were not statistically significant. Conclusions: BAER was the most frequent abnormality in SCA types 1, 2, and 3; abnormalities of mSSEP were comparable in the three SCAs; whereas, abnormality of VEP was less often noted in SCA3.

  20. Rcpititative magnetic stimulation of gastrocnemius muscle evokes cerebral potentials in Duchcnnc muscular dystrophy

    Cui Liying; Guan Yuzhou; Tang Xiaofu; Li Benhong


    OBJECTIVE: To study the function and mechanism of the ccrebral evoked potentials by repititative stimulation of calf muscle in Duchcnne mucular dystrophy (DMD) patients with obvious muscular dystrophy and pseudohyocrtrophy. METHODS: Wc measured cerebral cvoked potcntials by stimulation of calf muscles and SEP by stimulation of posterior tibial nerves at ankle in ten patients with DMD and ten normal controls matched with sex and age. The intensity of the magnetic stimulation was at 30% of maximal output (2.1 Tcsla) and the trcquency was I Hz. The low intensity of magnetic stimulation was just sufficient to produce a contraction of the muscle belly underncath the coil. Recording electrode was placed at 2 cm posterior to the Cz. referencc to Fpz. Thc latencics of N33. P38, N48 and P55 and amplitude (P38-N48) were recorded. SEP was recorded by routine methods. RESULTS: in normal subjects. thc amplitude of magnetic stimulation of calf muscle was 40% lower. and the latency of P38 was 2.9±2.1 ms longer compared with electrical stimulation of the posterior tibial nerves at ankle. In 6 patients. P38 latency from magnetic stimulation was remarkable prolonged (P<0.01). and in 4 patients. there no any response was found. SElP from electrical stimulation was normal in all patients. CONCLUSTION: DMD is an available model for the study of meclhanism of cerebral evoked potentials by magnetic stimulating muscles. Wc can coneludc that thc responses were produced by muscle input. The abnormal responses in patients may relate to decreased input of muscle by muscular dystrophy and pscudohypcrtrophy.

  1. MDMA (ecstasy) modulates locomotor and prefrontal cortex sensory evoked activity.

    Atkins, Kristal; Burks, Tilithia; Swann, Alan C; Dafny, Nachum


    Ingestion of 3, 4-methylenedioxymethamphetamine (MDMA) leads to heightened response to sensory stimulation; thus, MDMA is referred to as "ecstasy" because it produces pleasurable enhancement of such sensation. There have been no electrophysiological studies that report the consequences of MDMA on sensory input. The present study was initiated to study the effects of acute and chronic MDMA on locomotor activity and sensory evoked field potential from freely behaving rats previously implanted with permanent electrodes in the prefrontal cortex (PFC). The main findings of this study are that: (1) acute MDMA augments locomotor behavior and attenuates the incoming sensory input, (2) chronic treatment of MDMA elicits behavioral sensitization, (3) chronic administration of MDMA results in attenuation of the baseline activity of the sensory evoked field potential, and (4) administration of rechallenge MDMA result in enhancement of the PFC sensory evoked field potential. PMID:19769950

  2. Stimulator with arbitrary waveform for auditory evoked potentials

    Martins, H R; Romao, M; Placido, D; Provenzano, F; Tierra-Criollo, C J [Universidade Federal de Minas Gerais (UFMG), Departamento de Engenharia Eletrica (DEE), Nucleo de Estudos e Pesquisa em Engenharia Biomedica NEPEB, Av. Ant. Carlos, 6627, sala 2206, Pampulha, Belo Horizonte, MG, 31.270-901 (Brazil)


    The technological improvement helps many medical areas. The audiometric exams involving the auditory evoked potentials can make better diagnoses of auditory disorders. This paper proposes the development of a stimulator based on Digital Signal Processor. This stimulator is the first step of an auditory evoked potential system based on the ADSP-BF533 EZ KIT LITE (Analog Devices Company - USA). The stimulator can generate arbitrary waveform like Sine Waves, Modulated Amplitude, Pulses, Bursts and Pips. The waveforms are generated through a graphical interface programmed in C++ in which the user can define the parameters of the waveform. Furthermore, the user can set the exam parameters as number of stimuli, time with stimulation (Time ON) and time without stimulus (Time OFF). In future works will be implemented another parts of the system that includes the acquirement of electroencephalogram and signal processing to estimate and analyze the evoked potential.

  3. Electroencephalogram and evoked potential parameters examined in Chinese mild head injury patients for forensic medicine

    Xi-Ping CHEN; Lu-Yang TAO; Andrew CN CHEN


    Objective To evaluate the usefulness of quantitative electroencephalogram (QEEG), flash visual evoked potential (F-VEP) and auditory brainstem responses (ABR) as indicators of general neurological status. Methods Comparison was conducted on healthy controls (N=30) and patients with brain concussion (N=60) within 24 h after traumatic brain injury. Follow-up study of patient group was completed with the same standard paradigm 3 months later. All participants were recorded in multi-modality related potential testing in both early and late concussion at the same clinical setting. Glasgow coma scale, CT scanning, and physical examinations of neuro-psychological function, optic and auditory nervous system were performed before electroencephalogram (EEG) and evoked potential (EEG-EP) testing. Any participants showed abnormal changes of clinical examinations were excluded from the study. Average power of frequency spectrum and power ratios were selected for QEEG testing, and latency and amplitude of F-VEP and ABR were recorded.Results Between patients and normal controls, the results indicated: (1) Highly significance (P < 0.01) in average power of α1 and power ratios of θ/α1, θ/α2, α1/α2 of EEG recording; (2) N70-P100 amplitude of F-VEP in significant difference at early brain concussion; and (3) apparent prolongation of Ⅰ~Ⅲ inter-peak latency of ABR appeared in some individuals at early stage after concussion. The follow-up study showed that some patients with concussion were also afflicted with characteristic changes of EEG components for both increments of α1 average power and θ/α2 power ratio after 3 months recording. Conclusion EEG testing has been shown to be more effective and sensitive than evoked potential tests alone on detecting functional state of patients with mild traumatic brain injury (MTBI). Increments of α1 average power and θ/α2 power ratio are the sensitive EEG parameters to determining early concussion and evaluating outcome of

  4. Laryngotracheal Injury following Prolonged Endotracheal Intubation

    J. Mehdizadeh


    Full Text Available Background: Prolonged endotracheal intubation is a growing method for supporting ventilation in patients who require intensive care. Despite considerable advancement in endotracheal intubation, this method still has some complications; the most important is laryngo-tracheal injuries. Methods: Over a 2-year period, this retrospective study was conducted on 57 patients with history of prolonged intubation who were referred to the ENT Department of Amir Alam Hospital. For each patient, a complete evaluation including history, physical examination, and direct laryngoscopy and bronchoscopy was done under general anesthesia. Results: Fifty-seven patients (44 male; mean age, 23.014.7 years were studied. Mean intubation period was 15.88 days. The most common presenting symptom was dyspnea (62%. Head trauma was responsible for most cases of intubation (72.4%. The most common types of tracheal and laryngeal lesions were tracheal (56.9% and subglottic (55.2% stenosis, respectively. Mean length of tracheal stenosis was 0.810.83 cm. There was a statistically significant relationship between length of tracheal stenosis and intubation period (P=0.0001 but no relation was observed between tracheal stenosis and age, sex, and etiology of intubation (All P=NS. Among the glottic lesions, inter- arytenoids adhesion was the most common lesion (25.9%. No statistically significant relation was found between glottic and subglottic lesions and age, sex and intubation period (all P=NS. Length of stenosis and intubation period was significantly greater in tracheal/ subglottic lesions than those in glottic/ supraglottic lesions (all P=NS. Conclusion: After prolonged endotracheal intubation, laryngo-tracheal lesions had no relation with patient’s age, sex, and cause of intubation.There was direct relation between length of tracheal stenosis and intubation period. Glottic lesions were more commonly observed in head trauma patients. Lesion length and intubation

  5. [Cortical responses evoked by vibrotactile sensations in deaf children].

    Quaranta, A; Cipriani, D; Mininni, F


    Vibrotactile evoked responses (VER) to 250 and 500 Hz presented respectively at 50 and 70 dB HL by BC vibrator placed on right thumb, were recorded in 20 children (10 with pathological EEG) with severe sensorineural hearing loss, or deaf since birth, both to control accuracy of cortical responses to high intensity auditory stimuli and to diagnose central non auditory pathways lesions. The results have shown that: VER are present in subjects with severe sensorineural hearing loss or deaf; in children with auditory lesions VER have parameters different from auditory evoked response (AER); VER recording is not related both to the presence of auditory lesions and to neurological pathology. PMID:7448007

  6. Prolonged midazolam elimination half-life.

    Dundee, J W; Collier, P S; Carlisle, R J; Harper, K. W.


    The pharmacokinetics of a fixed dose of midazolam (0.3 mg kg-1 i.v.) were studied in detail in 115 healthy patients or volunteers and nine were found with a prolonged elimination half-life. A further 102 patients had an abbreviated pharmacokinetic study, of whom five showed a similar abnormality. Defective hepatic metabolism of midazolam may be a factor in the aetiology of what appears to be a true phenomenon, occurring in 6% of over 200 fit subjects given a standard dose of the drug.

  7. [Prolonged acute pancreatitis after bone marrow transplantation].

    De Singly, B; Simon, M; Bennani, J; Wittnebel, S; Zagadanski, A-M; Pacault, V; Gornet, J-M; Allez, M; Lémann, M


    Acute pancreatitis is not infrequent after allogenic marrow transplantation. Several causes can predispose to pancreatitis, including Graft-Versus-Host Disease (GVHD), a condition which is probably underestimated. In the literature, few description of pancreatic GVHD can be found. Pancreatic GVHD diagnosis can be difficult if pancreatic involvement occurs without other typical manifestations of GVHD. We report the case of a woman, 54 years old, suffering from prolonged, painful pancreatitis two months after allogenic bone marrow transplantation for acute myeloid leucemia. Pancreatic GVHD diagnosis was performed after five weeks on duodenal biopsies despite the absence of diarrheoa. The patient dramatically improved within few days on corticosteroids. PMID:18378104

  8. Lifetime Prolonging Algorithms for Underwater Sensor Networks

    GUO Zhong-wen; LI Zhi-wei; YU Lei


    Underwater acoustic modem technology has attained a level of maturity to support underwater acoustic sensor networks (UASNs) which are generally formed by acoustically connected sensor nodes and a surface station providing a link to an on-shore control center. While many applications require long-term monitoring of the deployment area, the battery-powered network nodes limit the lifetime of UASNs. Therefore, designing a UASN that minimizes the power consumption while maximizing lifetime becomes a very difficult task. In this paper, a method is proposed to determine the optimum number of clusters through combining an application-specific protocol architecture and underwater acoustic communication model so as to reduce the energy dissipation of UASNs. Deploying more sensor nodes which work alternately is another way to prolong the lifetime of UASNs. An algorithm is presented for selecting sensor nodes and putting them into operation in each round, ensuring the monitoring to the whole given area. The present results show that the algorithm can help prolong system lifetime remarkably when it is applied to other conventional approaches for sensor networks under the condition that the sensor node density is high.

  9. Evaluation of Evoked Potentials to Dyadic Tones after Cochlear Implantation

    Sandmann, Pascale; Eichele, Tom; Buechler, Michael; Debener, Stefan; Jancke, Lutz; Dillier, Norbert; Hugdahl, Kenneth; Meyer, Martin


    Auditory evoked potentials are tools widely used to assess auditory cortex functions in clinical context. However, in cochlear implant users, electrophysiological measures are challenging due to implant-created artefacts in the EEG. Here, we used independent component analysis to reduce cochlear implant-related artefacts in event-related EEGs of…

  10. Value of transcranial motor evoked potentials during spinal operations


    @@ To the Editor: We read the interesting recent article by Ding et al1 concerning the value of somatosensory evoked potentials (SEPs) in the diagnosis and prognosis of cervical spondylotic myelopathy, as well as the usefulness of monitoring intraoperative potentials in terms of safety and predictive factors.

  11. Auditory Brainstem Evoked Responses in Newborns with Down Syndrome

    Kittler, Phyllis M.; Phan, Ha T. T.; Gardner, Judith M.; Miroshnichenko, Inna; Gordon, Anne; Karmel, Bernard Z.


    Auditory brainstem evoked responses (ABRs) were compared in 15 newborns with Down syndrome and 15 sex-, age-, and weight-matched control newborns. Participants had normal ABRs based upon values specific to 32- to 42-weeks postconceptional age. Although Wave III and Wave V component latencies and the Wave I-III interpeak latency (IPL) were shorter…

  12. Cortical Auditory Evoked Potentials in Unsuccessful Cochlear Implant Users

    Munivrana, Boska; Mildner, Vesna


    In some cochlear implant users, success is not achieved in spite of optimal clinical factors (including age at implantation, duration of rehabilitation and post-implant hearing level), which may be attributed to disorders at higher levels of the auditory pathway. We used cortical auditory evoked potentials to investigate the ability to perceive…

  13. Single-sweep spectral analysis of contact heat evoked potentials

    Hansen, Tine M; Graversen, Carina; Frøkjaer, Jens B;


    AIMS: The cortical response to nociceptive thermal stimuli recorded as contact heat evoked potentials (CHEPs) may be altered by morphine. However, previous studies have averaged CHEPs over multiple stimuli, which are confounded by jitter between sweeps. Thus, the aim was to assess single-sweep ch...

  14. Methodologic aspects of acetylcholine-evoked relaxation of rabbit aorta.

    Hansen, K; Nedergaard, O A


    The acetylcholine-evoked relaxation of rabbit isolated thoracic aorta precontracted by phenylephrine was studied. Phenylephrine caused a steady contraction that was maintained for 6 h. In the presence of calcium disodium ethylenediaminetetraacetate (EDTA) and ascorbic acid the contraction decreased with time. N(G)-Nitro-L-arginine abolished the inhibitory effect of EDTA and ascorbic acid. Acetylcholine evoked a rapid concentration-dependent relaxation that recovered spontaneously and slowly, but fully, with time. Relaxation evoked by equieffective concentrations of carbachol and acetylcholine had the same time course. Cumulative addition of acetylcholine (10(-7)-3 x 10(-5) M) caused a marked relaxation that was reverted slightly at high concentrations. The relaxation was the same with rings derived from the upper, middle, and lower part of the thoracic aorta. Two consecutive concentration-response curves for acetylcholine obtained at a 2-h interval demonstrated a slight development of tachyphylaxis. The relaxation was inversely related to precontractile tension evoked by phenylephrine when expressed as a percentage, but independent when expressed as g tension. Storage of aorta in cold salt solution for 24 h did not alter the relaxation. EDTA and ascorbic acid did not alter the relaxation. It is concluded that (1) EDTA and ascorbic acid can not be used with impunity to stabilize catecholamines used as preconstriction agents; (2) the reversal of the acetylcholine-evoked relaxation is not due to hydrolysis of acetylcholine; (3) the relaxation is uniform in all segments of thoracic aorta; (4) cold storage of aorta does not alter the relaxation; and (5) acetylcholine releases the same amount of relaxing factor, irrespective of the precontractile tension. PMID:10691020

  15. Characterization of cardiovascular reflexes evoked by airway stimulation with allylisothiocyanate, capsaicin, and ATP in Sprague-Dawley rats.

    Hooper, J S; Hadley, S H; Morris, K F; Breslin, J W; Dean, J B; Taylor-Clark, T E


    Acute inhalation of airborne pollutants alters cardiovascular function and evidence suggests that pollutant-induced activation of airway sensory nerves via the gating of ion channels is critical to these systemic responses. Here, we have investigated the effect of capsaicin [transient receptor potential (TRP) vanilloid 1 (TRPV1) agonist], AITC [TRP ankyrin 1 (TRPA1) agonist], and ATP (P2X2/3 agonist) on bronchopulmonary sensory activity and cardiovascular responses of conscious Sprague-Dawley (SD) rats. Single fiber recordings show that allyl isothiocyanate (AITC) and capsaicin selectively activate C fibers, whereas subpopulations of both A and C fibers are activated by stimulation of P2X2/3 receptors. Inhalation of the agonists by conscious rats caused significant bradycardia, atrioventricular (AV) block, and prolonged PR intervals, although ATP-induced responses were lesser than those evoked by AITC or capsaicin. Responses to AITC were inhibited by the TRP channel blocker ruthenium red and the muscarinic antagonist atropine. AITC inhalation also caused a biphasic blood pressure response: a brief hypertensive phase followed by a hypotensive phase. Atropine accentuated the hypertensive phase, while preventing the hypotension. AITC-evoked bradycardia was not abolished by terazosin, the α1-adrenoceptor inhibitor, which prevented the hypertensive response. Anesthetics had profound effects on AITC-evoked bradycardia and AV block, which was abolished by urethane, ketamine, and isoflurane. Nevertheless, AITC inhalation caused bradycardia and AV block in paralyzed and ventilated rats following precollicular decerebration. In conclusion, we provide evidence that activation of ion channels expressed on nociceptive airway sensory nerves causes significant cardiovascular effects in conscious SD rats via reflex modulation of the autonomic nervous system. PMID:26718787

  16. Multifactorial QT Interval Prolongation and Takotsubo Cardiomyopathy

    Michael Gysel


    Full Text Available A 71-year-old woman collapsed while working as a grocery store cashier. CPR was performed and an AED revealed torsades de pointes (TdP. She was subsequently defibrillated resulting in restoration of sinus rhythm with a QTc interval of 544 msec. Further evaluation revealed a diagnosis of Takotsubo Cardiomyopathy (TCM contributing to the development of a multifactorial acquired long QT syndrome (LQTS. The case highlights the role of TCM as a cause of LQTS in the setting of multiple risk factors including old age, female gender, hypokalemia, and treatment with QT prolonging medications. It also highlights the multifactorial nature of acquired LQTS and lends support to growing evidence of an association with TCM.

  17. [Is prolonging life the ultimate goal?].

    Patzig, G


    If values are projections of human interests, prolongation of life cannot always be the highest value. Since the criterion of treatment decisions such cases must be the value of life for the individual concerned, besides "passive" euthanasia--which is widely accepted--also (indirectly and--in extreme cases--also directly) "active" euthanasia may be considered. The radical difference between this position and "euthanasia" in the "Third Reich" consists in the fact that, in our case, only the wishes and interests of the patient can be relevant, and not the decisions of authorities or considerations of expenses. Concerning the problem of just distribution of scarce medical resources, which will become more of on issue in the near future, simple solutions (e.g., a general age-limit for expensive therapy) are not helpful. More promising are considerations which start from the idea of a hypothetical health insurance, on the lines of J. Rawls' "Theory of justice". PMID:7863685

  18. Bilateral Scapulohumeral Ankylosis after Prolonged Mechanical Ventilation.

    van Lotten, Manon L; Schreinemakers, J Rieneke; van Noort, Arthur; Rademakers, Maarten V


    This case demonstrates a rarely reported bilateral scapulohumeral bony ankylosis. A young woman developed extensive heterotopic ossifications (HOs) in both shoulder joints after being mechanically ventilated for several months at the intensive care unit in a comatose status. She presented with a severe movement restriction of both shoulder joints. Surgical resection of the bony bridges was performed in 2 separate sessions with a significant improvement of shoulder function afterwards. No postoperative complications, pain, or recurrence of HOs were noted at 1-year follow-up. Mechanical ventilation, immobilization, neuromuscular blockage, and prolonged sedation are known risk factors for the development of HOs in the shoulder joints. Relatively early surgical resection of the HOs can be performed safely in contrary to earlier belief. Afterwards, nonsteroidal anti-inflammatory drugs and/or radiation therapy can be possible treatment modalities to prevent recurrence of HOs. PMID:27583120

  19. Prolonged parenteral nutrition after neonatal gastrointestinal surgery

    Estmann, Anne; Qvist, Niels; Husby, Steffen


    to diagnosis and clinical course. METHODOLOGY: This study reviews the clinical course of infants with gastrointestinal disease (gastroschisis, intestinal atresia, omphalocele, volvulus, Hirschsprung's disease and necrotizing enterocolitis) with a prolonged need for parenteral nutrition in the Western......INTRODUCTION: Long-term treatment with parenteral nutrition (PN) may be essential for survival in infants after neonatal gastrointestinal surgery. It seemed well indicated in a population-based study to estimate the need for long-term PN and to characterize the infants that received TPN with regard...... part of Denmark over a period of 11 1/2 years. RESULTS: A total of 21 patients with need for PN for 55 days or more due to gastrointestinal disease were registered with a cumulative hospital stay of 4462 days. The study showed a low incidence of long-term PN due to gastro-intestinal surgical illness...

  20. Neurohumoral responses during prolonged exercise in humans

    Nybo, Lars; Nielsen, Bodil; Blomstrand, Eva;


    This study examined neurohumoral alterations during prolonged exercise with and without hyperthermia. The cerebral oxygen-to-carbohydrate uptake ratio (O2/CHO = arteriovenous oxygen difference divided by arteriovenous glucose difference plus one-half lactate), the cerebral balances of dopamine, and...... the metabolic precursor of serotonin, tryptophan, were evaluated in eight endurance-trained subjects during exercise randomized to be with or without hyperthermia. The core temperature stabilized at 37.9 +/- 0.1 degrees C (mean +/- SE) in the control trial, whereas it increased to 39.7 +/- 0.2 degrees...... has an increased need for carbohydrates during recovery from strenuous exercise, whereas enhanced perception of effort as observed during exercise with hyperthermia was not related to alterations in the cerebral balances of dopamine or tryptophan....


    A. M. Chernyavskiy


    Full Text Available Clinical case of prolonged massive polyuria in patient after renal transplantation is represented in this article. Polyuria lasted for a forty days after kidney transplantation, the larges amount of urine output was 55 litres per day. Analysis of transplant biopsy revealed acute tubular necrosis, initial arteriolosclerosis and suspected acute rejection. Doppler ultrasound study and perfusion scintigraphy detected no pathology. At first we tried to decrease the volume of infusion and fluid intake. Also we performed pulse therapy with methylprednisolone. However, these efforts were not effective. Using of a large doses of «Minerin» (posterior pituitary antidiuretic factor allowed to decrease and stabilize the volume of urine output. The patient was discharge from clinic on day 42 after transplantation. 

  2. Effect of epidural clonidine on somatosensory evoked potentials to dermatomal stimulation

    Lund, C; Hansen, O B; Kehlet, H


    The effect of lumbar epidural clonidine 150 micrograms on early (less than 0.5 s) somatosensory evoked potentials (SEP) to electrical stimulation of the L1 and S1 dermatomes was examined in twelve cancer patients. Epidural clonidine led to a minor but significant decrease in amplitude of two...... systolic and diastolic blood pressures decreased from 118 +/- 4/72 +/- 5 mmHg to 99 +/- 5/60 +/- 3 mmHg (P less than 0.01), respectively. It is concluded that epidural clonidine has a minor effect on the early SEPs to electrical dermatomal stimulation. Additionally, a pronounced effect on cancer pain was...... components (N1 and N3) following S1 stimulation while SEP latency was prolonged only in the P1 and P3 components (P less than 0.05). In all patients the pain score decreased, mean score at rest from 4.9 +/- 0.5 to 0.6 +/- 0.2 and during mobilization from 7.4 +/- 0.6 to 1.3 +/- 0.5 (P less than 0.01). Mean...

  3. Cancer of endometrium and prolonged estrogen therapy.

    Fremont-smith, M; Meigs, J V; Graham, R M; Gilbert, H H


    A causal link between prolonged estrogen (E) therapy and endometrial cancer is argued for in this report of a case who was treated with large amounts of estrogenic substances almost continuously for an 8-year period. In 1919 a 25-year-old woman was admitted with asthma of 1-year duration. Asthma onset had been very severe, requiring administration of epinephrine hydrochloride every few hours and frequent hospital observation. In 1928, the patient was amenorrheic for 8 months; in 1936, she experienced amenorrhea for 4 months. In 1937 (patient now 45 years old), the relationship between amenorrhea and increased severity of asthma was suspected. At this time, the patient also complained of hot flashes and sweats. Treatment with estrogenic substances was begun in 1937 and continued through 1945. 3 unusual features were noted during therapy: 1) persistence of hot flashes; 2) persistence of high urine titers of follicle stimulating hormone (FSH) despite adequate E doses; and 3) absence of bleeding when E was temporarily withdrawn. By 1945, endometrial cancer had been identified by vaginal smear and verified by biopsy. Because of the previous absence of respose of FSH to prolonged E therapy, Es were omitted for 4 weeks, and after this period the vaginal smear showed complete absence of intrinsic estrogenic stimulation, and the urine titer of FSH was high. E given for 10 days caused moderate pituitary inhibition. Determination of 17-keto-steroids made before and after therapy was abnormally low. Except for the state of chronic illness and the continuous administration of asthma medication (chronic alarm reaction?), there is no explanation of carcinoma grade 2. PMID:12334535

  4. Effects of Prolonged Centrifugation on Orthostasis

    Cohen, Malcolm M..; Hargens, A. R.; Yates, B. J.; Bowley, Susan M. (Technical Monitor)


    A feasibility study conducted on the Ames 20-G Human Centrifuge examined how well humans can maintain orthostatic tolerance during and after prolonged exposures to hypergravity. Three adult males lived for periods of 22 hours in the centrifuge while it was at rest (1.00 G), and while it rotated at 9.38 RPM to provide 1.25 G-total at the mean radius of 7.62 m. Two participants also experienced 22-hour habitation sessions at 11.46 RPM, which provided 1.50 G-total. Both before and after each habitation session, the participants were given gradual onset rate (GOR) acceleration profiles at 0.067 G/sec to determine their Gz tolerance. In addition, cardiovascular responses were compared while subjects were supine, siting, and standing at various times during the habitation (stand test), and cardiovascular responsiveness was determined using a lower body negative pressure tilt table (LBNPTT) at the beginning of the experiment and after each session. Post-Pre changes in G tolerance were -0.33 (mean) +/- 0.11 (std. error) Gz for habitation at 1.00 G, -0.02 +/- 0.12 Gz for habitation at 1.25 G, and +0.41 +/- 0.13 Gz for habitation at 1.50 G. Performance on the stand test generally improved with duration of habitation in hypergravity. Our results suggest that habitation in a confined chamber at 1.00 G reduces G tolerance and leads to lowered LBNPTT tolerance. Exposure to increased G in the centrifuge leads to enhanced performance on the stand test, and to increased GOR acceleration tolerance, but only when fluid balance is maintained; when motion sickness and negative fluid balance were observed, G tolerance was reduced. The data indicate that enhanced G tolerance can result from prolonged exposure to hypergravity, but that these changes are complex and depend on multiple underlying physiological processes.

  5. An inventory and update of jealousy-evoking partner behaviours in modern society.

    Dijkstra, Pieternel; Barelds, Dick P. H.; Groothof, Hinke A. K.


    The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's e

  6. Severe QT interval prolongation associated with moxifloxacin: a case report

    Koide, Tetsuro; Shiba, Masato; Tanaka, Katsuhiro; Muramatsu, Masatoshi; Ishida, Satoshi; Kondo, Yoshihiro; Watanabe, Keiko


    Introduction The QT interval prolongation is an adverse effect associated with moxifloxacin. This adverse effect can lead to potentially life-threatening arrhythmias such as Torsades de pointes. We describe a case of severe QT interval prolongation associated with moxifloxacin which may cause the development of Torsades de pointes. There have been no reported case of severe corrected QT interval prolongation caused by moxifloxacin in the patient of normal heart rate. Case presentation In an 8...

  7. A geometric interpretation of prolongation by means of connections

    Bracken, Paul


    A geometric interpretation of prolongation can be formulated by using the theory of connections. A fiber bundle can be established which is composed of a base manifold and variables which span a prolongation space. A particular connection is introduced in terms of these coordinates. This provides a very different way of viewing the technique and for introducing prolongation algebras as well as generating integrable equations in a novel way.

  8. Grace's story: prolonged incestuous abuse from childhood into adulthood.

    Salter, Michael


    Some sexually abused women in mental health settings are reporting prolonged incest and yet little is known about the circumstances that enable fathers to sexually abuse their daughters over a period of decades. This article draws from the life history of Grace, a woman who survived prolonged incest, in order to document and analyze the interplay of familial, social, and political factors that entrap girls and women within prolonged incestuous abuse. PMID:23420835

  9. Abdominal acupuncture reduces laser-evoked potentials in healthy subjects

    Pazzaglia, C.; Liguori, S.; Minciotti, I.;


    Objective: Acupuncture is known to reduce clinical pain, although the exact mechanism is unknown. The aim of the current study was to investigate the effect of acupuncture on laser-evoked potential amplitudes and laser pain perception. Methods: In order to evaluate whether abdominal acupuncture is...... able to modify pain perception, 10 healthy subjects underwent a protocol in which laser-evoked potentials (LEPs) and laser pain perception were collected before the test (baseline), during abdominal acupuncture, and 15. min after needle removal. The same subjects also underwent a similar protocol in...... real acupuncture, although the difference was marginally significant (p = 0.06). Conclusions: Our results show that abdominal acupuncture reduces LEP amplitude in healthy subjects. Significance: Our results provide a theoretical background for the use of abdominal acupuncture as a therapeutic approach...

  10. [Evoked cortical somatosensory potentials in painful cervicobrachial radicular syndromes].

    Domzał, T; Marks, E; Miszczak, J


    The authors determined the subjective, objective and maximal pain threshold by means of electrical stimulation in two groups of subjects. Group I comprised healthy subjects, group II patients with right-sided radicular cervicobrachial pains. The method applied by the authors for objective determination of pain threshold with evoked cortical somatosensory potential differentiated both groups which suggests its practical usefulness in clinical practice and expertise. PMID:683429

  11. Hindlimb venous distention evokes a pressor reflex in decerebrated rats

    Yamauchi, Katsuya; Audrey J. Stone; Kaufman, Marc P.


    Abstract The distention of small vessels caused by an increase in blood flow to dynamically exercising muscles has been proposed as a stimulus that activates the thin fiber (groups III and IV) afferents evoking the exercise pressor reflex. This theory has been supported by evidence obtained from both humans and animals. In decerebrated unanesthetized rats with either freely perfused femoral arteries or arteries that were ligated 3 days before the experiment, we attempted to provide evidence i...

  12. Brainstem reflexes and brainstem auditory evoked responses in Huntington's chorea.

    Bollen, E; Arts, R.J.; Roos, R A; van der Velde, E A; Buruma, O J


    Blink reflex, corneal reflex, jaw reflex, exteroceptive suppression in masseter muscles and brainstem auditory evoked potentials were measured in 20 patients with Huntington's chorea and 12 controls. A significantly increased latency of the second component of the homolateral and heterolateral blink reflex was found in the patient group as compared with the controls. The other investigations revealed no significant differences between patients and controls except for some facilitation of the ...

  13. Influence of temperature on the sound-evoked vestibular potential.

    Wit, H P; Dijkgraaf, E


    The sound-evoked vestibular potential, measured with gross electrodes after fenestration of a lateral semicircular canal in pigeons, is delayed with respect to the acoustic stimulus. The influence of temperature of the vestibular system on this delay can most easily be explained by assuming chemically mediated transmission to take place between vestibular hair cells and their primary afferents. The possibility of electrotonic transmission, however, cannot be excluded. PMID:3878654

  14. Functional prognosis in stroke: use of somatosensory evoked potentials.

    Zeman, B D; Yiannikas, C


    Median nerve somatosensory evoked potentials (SEPs) were performed on 35 patients with acute stroke and correlated with functional outcome as measured by placement, length of stay and an activities of daily living index (Barthel Index). There was a statistically significant correlation of both SEP and sensory examination at the 0.05 level to eventual functional outcome. SEPs were better than age, sex and side of CVA in predicting functional outcome as measured by these scores. SEPs and sensor...

  15. Somatosensory evoked potentials in workers exposed to toluene and styrene.

    Stĕtkárová, I; Urban, P.; Procházka, B; Lukás, E


    Somatosensory evoked potentials (SEPs) were used to evaluate possible subclinical impairment of the nervous system due to occupational exposure to toluene and styrene. A group of 36 rotogravure printers with severe exposure to toluene, 20 workers with severe exposure to styrene in a glass laminate manufacturing plant, and a comparison group of healthy subjects were studied. The severity of exposure was documented by measurements of toluene and styrene concentrations in breathing zone air, by ...

  16. Pain-related somatosensory evoked potentials in cortical reflex myoclonus.

    Kakigi, R; Shibasaki, H; Neshige, R; Ikeda, A.; Mamiya, K.; Kuroda, Y


    To elucidate the sensitivity to pain stimuli in patients with cortical reflex myoclonus, pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation and conventional electrically-stimulated SEPs (electric SEPs) were compared in four patients with cortical reflex myoclonus. The P25 peak of electric SEPs was considerably enhanced but the P320 potential of pain SEPs was of normal amplitude in all patients. After medication, myoclonus was reduced and the amplitude of ...

  17. Estimating loudness growth from tone-burst evoked responses

    Silva, Ikaro; Epstein, Michael


    Several studies have investigated the relationship between click-evoked auditory brainstem responses (ABRs) and loudness growth in human listeners. While some of these studies have reported promising results, showing a correlative relationship between click ABR and loudness growth as a function of level, additional studies are necessary to determine if similar results can be obtained with frequency-specific stimuli and more specific details of the loudness function can be derived from ABR rec...

  18. The Dynamic Functional Capacity Theory: Music Evoked Emotions

    Klineburger, Philip C


    The music-evoked emotion literature implicates many brain regions involved in emotional processing but is currently lacking a model that specifically explains how they temporally and dynamically interact to produce intensely pleasurable emotions. A conceptual model, The Dynamic Functional Capacity Theory (DFCT), is proposed that provides a foundation for the further understanding of how brain regions interact to produce intense intensely pleasurable emotions. The DFCT claims th...

  19. The impact of emotion on respiratory-related evoked potentials

    von Leupoldt, Andreas; Vovk, Andrea; Bradley, Margaret M.; Keil, Andreas; Lang, Peter J.; Davenport, Paul W.


    Emotion influences the perception of respiratory sensations, although the specific mechanism underlying this modulation is not yet clear. We examined the impact of viewing pleasant, neutral, and unpleasant affective pictures on the respiratory-related evoked potential (RREP) elicited by a short inspiratory occlusion in healthy volunteers. Reduced P3 amplitude of the RREP was found for respiratory probes presented when viewing pleasant or unpleasant series, when compared to those presented dur...

  20. The Effect of Threat on Novelty Evoked Amygdala Responses

    Balderston, Nicholas L.; Schultz, Doug H.; Helmstetter, Fred J.


    A number of recent papers have suggested that the amygdala plays a role in the brain’s novelty detection circuit. In a recent study, we showed that this role may be specific to certain classes of biologically-relevant stimuli, such as human faces. The purpose of the present experiment was to determine whether other biologically-relevant stimuli also evoke novelty specific amygdala responses. To test this idea, we presented novel and repeated images of snakes and flowers while measuring BOLD. ...

  1. Auditory Evoked Potential Response and Hearing Loss: A Review

    Paulraj, M. P; Subramaniam, Kamalraj; Yaccob, Sazali Bin; Adom, Abdul H. Bin; Hema, C.R.


    Hypoacusis is the most prevalent sensory disability in the world and consequently, it can lead to impede speech in human beings. One best approach to tackle this issue is to conduct early and effective hearing screening test using Electroencephalogram (EEG). EEG based hearing threshold level determination is most suitable for persons who lack verbal communication and behavioral response to sound stimulation. Auditory evoked potential (AEP) is a type of EEG signal emanated from the brain scalp...

  2. An evoked potential mapping of transcallosal projections in the cat

    A. Cukiert; C. Timo-Iaria


    In ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity) were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions were determined on a cartesian map of most of the exposable neocortical areas and the potentials were analysed as to their components, voltage and latency. Passive spread and electrotonic potentials a...

  3. An evoked indirect response in the cervical vagal nerve

    Ordelman, S.C.M.A.; Kornet, L.; Cornelussen, R.; Buschman, H.P.J.; Veltink, P.H.


    The response of fibers in the vagal nerve, evoked by electrical stimulation, has been studied in both animals and humans. These compound action potentials (CAPs) consist of components coming from thick, myelinated fibers to thin, unmyelinated fibers. In our study, the possibility is addressed of an indirect component in the CAP which is involved in reflexive control. By using multiple, consecutive electrode sites along the cervical vagal nerve, both the direction and the velocity along the ne...

  4. Assessment of visual disability using visual evoked potentials

    Jeon Jihoon; Oh Seiyul; Kyung Sungeun


    Abstract Background The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. Methods A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for regist...

  5. A Sequential Detection Method for Late Auditory Evoked Potentials

    Hoppe, U; Eysholdt, U; Weiss, S.


    This work presents a novel mechanism for detection of late auditory evoked potentials (AEP). AEPs, which are an important diagnostic tool to detect hearing deficiencies, are contained within the electroencephalogram (EEG) at a very low SNR. Our proposed automatic detection of AEPs is based on the Wavelet-Transform of EEG data for feature extraction. Several transform coefficients are then used for a classification by a neural network; its decisions on successive EEG segments are judged by a s...

  6. Somatosensory evoked potentials and outcome in perinatal asphyxia.

    Gibson, N A; Graham, M.; Levene, M I


    Somatosensory evoked potentials (SEP) can be measured in the term newborn infant and given an index of function in the areas of the brain most likely to be damaged in perinatal asphyxia. We studied the median nerve SEP in 30 asphyxiated term infants over the course of their encephalopathy and until discharge from the neonatal unit. Three types of response were noted: normal waveform, abnormal waveform, or absence of cortical response. Follow up of the survivors was undertaken at a mean age of...

  7. Visual evoked potentials in succinate semialdehyde dehydrogenase (SSADH) Deficiency

    Di Rosa, G.; Malaspina, P; P. Blasi(INAF Arcetri); Dionisi-Vici, C.; Rizzo, C; Tortorella, G; Crutchfield, S. R.; Gibson, K. M.


    In mammals, increased GABA in the central nervous system has been associated with abnormalities of visual evoked potentials (VEPs), predominantly manifested as increased latency of the major positive component P100. Accordingly, we hypothesized that patients with a defect in GABA metabolism, succinate semialdehyde dehydrogenase (SSADH) deficiency (in whom supraphysiological levels of GABA accumulate), would manifest VEP anomalies. We evaluated VEPs on two patients with confirmed SSADH deficie...

  8. Short latency vestibular evoked potentials in the chicken embryo

    Jones, S. M.; Jones, T. A.


    Electrophysiological responses to pulsed linear acceleration stimuli were recorded in chicken embryos incubated for 19 or 20 days (E19/E20). Responses occurred within the first 16 ms following the stimulus onset. The evoked potentials disappeared following bilateral labyrinthectomy, but persisted following cochlear destruction alone, thus demonstrating that the responses were vestibular. Approximately 8 to 10 response peaks could be identified. The first 4 positive and corresponding negative components (early peaks with latencies birds. Mean response threshold for anesthetized embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P birds (-23.0dBre 1.0 g/ms). Latency/intensity functions (that is, slopes) were not significantly different between embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P function that occurs following 19 to 20 days of incubation. The recording of vestibular evoked potentials provides an objective, direct and noninvasive measure of peripheral vestibular function in the embryo and, as such, the method shows promise as an investigative tool. The results of the present study form the definitive basis for using vestibular evoked potentials in the detailed study of avian vestibular ontogeny and factors that may influence it.

  9. Brainstem auditory evoked potentials in children with lead exposure

    Katia de Freitas Alvarenga


    Full Text Available Introduction: Earlier studies have demonstrated an auditory effect of lead exposure in children, but information on the effects of low chronic exposures needs to be further elucidated. Objective: To investigate the effect of low chronic exposures of the auditory system in children with a history of low blood lead levels, using an auditory electrophysiological test. Methods: Contemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6 years, 8 months ± 3 years, 2 months. Results: The mean time-integrated cumulative blood lead index was 12 µg/dL (SD ± 5.7, range:2.433. All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I-III, III-V, and I-V, and the cumulative lead values. Conclusion: No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area.

  10. Optical suppression of drug-evoked phasic dopamine release

    James Edgar Mccutcheon


    Full Text Available Brief fluctuations in dopamine concentration (dopamine transients play a key role in behavior towards rewards, including drugs of abuse. Drug-evoked dopamine transients may result from actions at both dopamine cell bodies and dopamine terminals. Inhibitory opsins can be targeted to dopamine neurons permitting their firing activity to be suppressed. However, as dopamine transients can become uncoupled from firing, it is unknown whether optogenetic hyperpolarization at the level of the soma is able to suppress dopamine transients. Here, we used in vivo fast-scan cyclic voltammetry to record transients evoked by cocaine and raclopride in nucleus accumbens (NAc of urethane-anesthetized rats. We targeted halorhodopsin (NpHR specifically to dopamine cells by injecting Cre-inducible virus into ventral tegmental area (VTA of transgenic rats that expressed Cre recombinase under control of the tyrosine hydroxylase promoter (TH-Cre+ rats. Consistent with previous work, co-administration of cocaine and raclopride led to the generation of dopamine transients in NAc shell. Illumination of VTA with laser strongly suppressed the frequency of transients in NpHR-expressing rats, but not in control rats. Laser did not have any effect on amplitude of transients. Thus, optogenetics can effectively reduce the occurrence of drug-evoked transients and is therefore a suitable approach for studying the functional role of such transients in drug-associated behavior.

  11. Vestibular-evoked myogenic potentials in miniature pigs

    Xi Shi; Yan Zhang; Ya Li; Shiwei Qiu; Shili Zhang; Yaohan Li; Na Yuan; Yuehua Qiao; Shiming Yang


    Objective:To report detection of vestibular-evoked myogenic potentials (VEMPs) in the miniature pig. Methods:Potentials evoked by 1000 Hz tone bursts were recorded from neck extensor muscles and the masseter muscles in normal adult Bama miniature pigs anesthetized with 3%pentobarbital sodium and Carbachol II. Results:The latency of the first positive wave P from neck extensor muscles was 7.65 ± 0.64 ms, with an amplitude of 1.66 ± 0.34 uv and a rate of successful induction of 75%at 80 dB SPL. The latency of potentials evoked from the masseter muscles was 7.60 ± 0.78 ms, with an amplitude of 1.31 ± 0.28 uv and a rate successful induction of 66%at 80 dB SPL. Conclusion:The latencies and thresholds of VEMPs recorded from the neck extensor muscle and the masseter muscle appear to be comparable in normal adult Bama miniature pigs, although the amplitude recorded from the neck extensor muscle seems to be higher than that from the masseter muscle. However, because of their usually relatively superficial and easily accessible location, as well as their large volume and strong contractions, masseter muscles may be better target muscles for recording myogenic potentials.

  12. Baroreceptor activation attenuates attentional effects on pain-evoked potentials.

    Gray, Marcus A; Minati, Ludovico; Paoletti, Giulia; Critchley, Hugo D


    Focused attention typically enhances neural nociceptive responses, reflected electroencephalographically as increased amplitude of pain-evoked event-related potentials (ERPs). Additionally, pain-evoked ERPs are attenuated by hypertension and baroreceptor activity, through as yet unclear mechanisms. There is indirect evidence that these two effects may interact, suggesting that baroreceptor-related modulation of nociception is more than a low-level gating phenomenon. To address this hypothesis, we explored in a group of healthy participants the combined effects of cue-induced expectancy and baroreceptor activity on the amplitude of pain-evoked ERPs. Brief nociceptive skin stimuli were delivered during a simple visual task; half were preceded by a visual forewarning cue, and half were unpredictable. Nociceptive stimuli were timed to coincide either with systole (maximum activation of cardiac baroreceptors) or with diastole (minimum baroreceptor activation). We observed a strong interaction between expectancy and cardiac timing for the amplitude of the P2 ERP component; no effects were observed for the N2 component. Cued stimuli were associated with larger P2 amplitude, but this effect was abolished for stimuli presented during baroreceptor activation. No cardiac timing effect was observed for un-cued stimuli. Taken together, these findings suggest a close integration of cognitive-affective aspects of expectancy and baroreceptor influences on pain, and as such may cast further light on mechanisms underlying mental and physiological contributions to clinical pain. PMID:20965656

  13. Submillisecond unmasked subliminal visual stimuli evoke electrical brain responses.

    Sperdin, Holger F; Spierer, Lucas; Becker, Robert; Michel, Christoph M; Landis, Theodor


    Subliminal perception is strongly associated to the processing of meaningful or emotional information and has mostly been studied using visual masking. In this study, we used high density 256-channel EEG coupled with an liquid crystal display (LCD) tachistoscope to characterize the spatio-temporal dynamics of the brain response to visual checkerboard stimuli (Experiment 1) or blank stimuli (Experiment 2) presented without a mask for 1 ms (visible), 500 µs (partially visible), and 250 µs (subliminal) by applying time-wise, assumption-free nonparametric randomization statistics on the strength and on the topography of high-density scalp-recorded electric field. Stimulus visibility was assessed in a third separate behavioral experiment. Results revealed that unmasked checkerboards presented subliminally for 250 µs evoked weak but detectable visual evoked potential (VEP) responses. When the checkerboards were replaced by blank stimuli, there was no evidence for the presence of an evoked response anymore. Furthermore, the checkerboard VEPs were modulated topographically between 243 and 296 ms post-stimulus onset as a function of stimulus duration, indicative of the engagement of distinct configuration of active brain networks. A distributed electrical source analysis localized this modulation within the right superior parietal lobule near the precuneus. These results show the presence of a brain response to submillisecond unmasked subliminal visual stimuli independently of their emotional saliency or meaningfulness and opens an avenue for new investigations of subliminal stimulation without using visual masking. PMID:25487054

  14. Brainstem auditory evoked potential abnormalities in type 2 diabetes mellitus

    Sharat Gupta


    Full Text Available Background: Diabetes mellitus represents a syndrome complex in which multiple organ systems, including the central nervous system, are affected. Aim: The study was conducted to determine the changes in the brainstem auditory evoked potentials in type 2 diabetes mellitus. Materials and Methods: A cross sectional study was conducted on 126 diabetic males, aged 35-50 years, and 106 age-matched, healthy male volunteers. Brainstem auditory evoked potentials were recorded and the results were analyzed statistically using student′s unpaired t-test. The data consisted of wave latencies I, II, III, IV, V and interpeak latencies I-III, III-V and I-V, separately for both ears. Results: The latency of wave IV was significantly delayed only in the right ear, while the latency of waves III, V and interpeak latencies III-V, I-V showed a significant delay bilaterally in diabetic males. However, no significant difference was found between diabetic and control subjects as regards to the latency of wave IV unilaterally in the left ear and the latencies of waves I, II and interpeak latency I-III bilaterally. Conclusion: Diabetes patients have an early involvement of central auditory pathway, which can be detected with fair accuracy with auditory evoked potential studies.

  15. Prolonging sensor networks lifetime using convex clusters

    Payam Salehi


    Full Text Available Reducing the energy consumption of nodes in sensor networks and prolonging the network life time has been proposed as one of the most important challenges facing researchers in the field of sensor networks. Therefore, designing an energy-aware protocol to gather data from network level and transmitting it to sink is placed on the agenda at this paper. After presenting an analysis of the processes of clustering in sensory networks and investigating the effect of sending interval on the amount of energy consumption, We have shown that if the use of convex static casters be done such as all the communications within the cluster with the sending distance less than the optimal threshold, it Will help to increase the lifetime of nodes. also have shown that if we create a virtual backbone between cluster heads to transfer far cluster heads data from sink to sink , will has a significant impact on increasing the network lifetime. For this reason, a detailed discussion on how to determine the size of clusters and partitioning of the network environment to them is presented in Chapter 4.Simulation results show considerable improvement of the proposed algorithm.

  16. [A case of prolonged paroxysmal sympathetic hyperactivity].

    Yamamoto, Akiko; Ide, Shuhei; Iwasaki, Yuji; Kaga, Makiko; Arima, Masataka


    We report the case of a 4-year-old girl who presented with paroxysmal sympathetic hyperactivity (PSH), after developing severe hypoxic-ischemic-encephalopathy because of cardiopulmonary arrest. She showed dramatic paroxysmal sympathetic activity with dystonia. She was treated with wide variety of medications against PSH, which were found to be effective in previous studies. Among them, morphine, bromocriptine, propranolol, and clonidine were effective in reducing the frequency of her attacks while gabapentin, baclofen, dantrolene, and benzodiazepine were ineffective. Though the paroxysms decreased markedly after the treatment, they could not be completely controlled beyond 500 days. Following the treatment, levels of plasma catecholamines and their urinary metabolites decreased to normal during inter- paroxysms. However, once a paroxysm had recurred, these levels were again very high. This case study is considered significant for two rea- sons. One is that PSH among children have been rarely reported, and the other is that this case of prolonged PSH delineated the transition of plasma catecholamines during the treatment. The excitatory: inhibitory ratio (EIR) model proposed by Baguley was considered while dis- cussing drug sensitivity in this case. Accumulation of similar case studies will help establish more effective treatment strategies and elucidate the pathophysiology of PSH. PMID:27149743

  17. Encephalitis with Prolonged but Reversible Splenial Lesion

    Alena Meleková


    Full Text Available Introduction: The splenium of the corpus callosum has a specific structure of blood supply with a tendency towards blood-brain barrier breakdown, intramyelinic edema, and damage due to hypoxia or toxins. Signs and symptoms of reversible syndrome of the splenium of the corpus callosum typically include disorientation, confusion, impaired consciousness, and epileptic seizures. Case report: A previously healthy 32-year-old man suffered from weakness, headache, and fever. Subsequently, he developed apathy, ataxia, and inability to walk, and therefore was admitted to the hospital. Cerebrospinal fluid showed protein elevation (0.9 g/l and pleocytosis (232/1 ul. A brain MRI showed hyperintense lesions in the middle of the corpus callosum. The patient was treated with antibiotics, and subsequently, in combination with steroids. Two months later, the hyperintense lesions in the splenium and the basal ganglia had disappeared. Almost seven months since his hospitalization in the Department of Neurology, the patient has returned to his previous employment. He now does not exhibit any mental changes, an optic edema and urological problems have improved. In addition, he is now actively engaged in sports. Conclusion: We have described a case of a 32-year-old man with confusion, ataxia, and inability to stand and walk. The man developed a febrile meningeal syndrome and a hyperintense lesion of the splenium, which lasted for two months. Neurological changes, optic nerve edema, and urinary retention have resolved over the course of seven months. We think that the prolonged but transient lesion of the splenium may have been caused by encephalitis of viral origin.

  18. Epidemiology of prolonged testicular infections with bovine viral diarrhea virus.

    Givens, M Daniel; Riddell, Kay P; Edmondson, Misty A; Walz, Paul H; Gard, Julie A; Zhang, Yijing; Galik, Patricia K; Brodersen, Bruce W; Carson, Robert L; Stringfellow, David A


    Previously, bovine viral diarrhea virus (BVDV) had been found in prolonged testicular infections following acute infection of immunocompetent bulls. The primary purpose of this research was to evaluate the production and maintenance of prolonged testicular infections after exposure to BVDV of seronegative bulls in varying circumstances. The secondary objective was to initiate assessment of the potential for transmission of BVDV via semen of bulls exhibiting a prolonged testicular infection. In total, 10 research trials were conducted. The first trial examined the duration of detectable virus in semen after intranasal inoculation of peri-pubertal bulls. The second to fifth trials examined the potential for prolonged testicular infections resulting from natural exposure of seronegative bulls to persistently infected heifers. In the last five trials, the potential for viral transmission from bulls exhibiting prolonged testicular infections to a small number of exposed animals (n=28) was evaluated. Results of this research demonstrated that prolonged testicular infections could result in detection of viral RNA in semen for 2.75 years with infectious virus grown from testicular tissue 12.5 months after viral exposure. A type 1b strain of BVDV caused prolonged testicular infection after natural exposure of seronegative bulls to a persistently infected heifer. However, transmission of BVDV to susceptible animals was not detected in the final five trials of this research. In conclusion, BVDV can persist in testicular tissue after acute infection for several years, but the potential for viral transmission from these prolonged testicular infections appears to be low. PMID:19473788

  19. Peripheral prostaglandin E2 prolongs the sensitization of nociceptive dorsal root ganglion neurons possibly by facilitating the synthesis and anterograde axonal trafficking of EP4 receptors.

    St-Jacques, Bruno; Ma, Weiya


    Prostaglandin E2 (PGE2), a well-known pain mediator enriched in inflamed tissues, plays a pivotal role in the genesis of chronic pain conditions such as inflammatory and neuropathic pain. PGE2-prolonged sensitization of nociceptive dorsal root ganglion (DRG) neurons (nociceptors) may contribute to the transition from acute to chronic pain. However, the underlying cellular mechanisms are poorly understood. In this study, we tested the hypothesis that facilitating synthesis and anterograde axonal trafficking of EP receptors contribute to PGE2-prolonged nociceptor sensitization. Intraplantar ( injection of a stabilized PGE2 analog, 16,16 dimethyl PGE2 (dmPGE2), in a dose- and time-dependent manner, not only elicited primary tactile allodynia which lasted for 1d, but also prolonged tactile allodynia evoked by a subsequent injection of dmPGE2 from 1d to 4d. Moreover, the duration of tactile allodynia was progressively prolonged following multiple sequential injections of dmPGE2. Co-injection of the selective EP1 or EP4 receptor antagonist, the inhibitors of cAMP, PKA, PKC, PKCε or PLC as well as an interleukin-6 (IL-6) neutralizing antiserum differentially blocked primary tactile allodynia elicited by the 1st dmPGE2 and the prolonged tactile allodynia evoked by the 2nd dmPGE2, suggesting the involvement of these signaling events in dmPGE2-induced nociceptor activation and sensitization. Co-injection of a selective COX2 inhibitor or two EP4 antagonists prevented or shortened inflammagen-prolonged nociceptor sensitization. injection of dmPGE2 or carrageenan time-dependently increased EP4 levels in L4-6 DRG neurons and peripheral nerves. EP4 was expressed in almost half of IB4-binding nociceptors of L4-6 DRG. Taken together, our data suggest that stimulating the synthesis and anterograde axonal trafficking to increase EP4 availability at the axonal terminals of nociceptors is likely a novel mechanism underlying PGE2-prolonged nociceptor

  20. Drug-induced QT interval prolongation in cancer patients

    Torben K. Becker


    Full Text Available Cancer patients are at an increased risk for QT interval prolongation and subsequent potentially fatal Torsade de pointes tachycardia due to the multiple drugs used for treatment of malignancies and the associated symptoms and complications. Based on a systematic review of the literature, this article analyzes the risk for prolongation of the QT interval with antineoplastic agents and commonly used concomitant drugs. This includes anthracyclines, fluorouracil, alkylating agents, and new molecularly targeted therapeutics, such as vascular disruption agents. Medications used in the supportive care can also prolong QT intervals, such as methadone, 5-HT3-antagonists and antihistamines, some antibiotics, antifungals, and antivirals. We describe the presumed mechanism of QT interval prolongation, drug-specific considerations, as well as important clinical interactions. Multiple risk factors and drug–drug interactions increase this risk for dangerous arrhythmias. We propose a systematic approach to evaluate cancer patients for the risk of QT interval prolongation and how to prevent adverse effects.

  1. Prediction of Prolonged Hemodynamic Instability During Carotid Angioplasty and Stenting

    Rhim, Jong Kook; Park, Jeong Jin; Choi, Hyuk Jai; Cho, Young Dae; Sheen, Seung Hun; Jang, Kyung-Sool


    Purpose The aim of this study was to assess the risk factors of prolonged hemodynamic instability (HDI) after carotid angioplasty and stenting (CAS). Herein, a simplified predictive scoring system for prolonged HDI is proposed. Materials and Methods Sixty-six patients who had CAS from 2011 to 2016 at a single institution were evaluated. Prolonged HDI was defined as systolic blood pressure >160 mm Hg or <90 mm Hg or heart rate <50 beats/min, lasting over 30 minutes despite medical treatments. For the study, clinical data and radiologic data, including plaque morphology and stenosis were analyzed. Results Prolonged HDI was observed in 21 patients (31.8%). Multivariable analysis revealed that calcification (OR, 6.726; p=0.006), eccentric stenosis (OR, 3.645; p=0.047) and extensive plaque distribution (OR, 7.169; p=0.006) were related to prolonged HDI. According to these results, a simplified scoring scale was proposed based on the summation of points: 2 points for calcified plaque, 2 points for extensive plaque distribution, and 1 point for eccentric stenosis. The percentages of prolonged HDI according to the total score were as follows: score 0, 8.7%; score 1, 20.0%; score 2, 38.5%; score 3, 72.7%; score 4, 66.7%; score 5, 100%. From the analysis, the total score in patients with prolonged HDI was significantly higher than those without prolonged HDI (p<0.001). Conclusion Prolonged HDI can be associated with calcification of plaque, eccentric stenosis and extensive plaque distribution, and a simplified scoring system enables prediction of prolonged HDI according to our cohort.

  2. Cortical modulation of short-latency TMS-evoked potentials

    Domenica eVeniero


    Full Text Available Transcranial magnetic stimulation - electroencephalogram (TMS-EEG co-registration offers the opportunity to test reactivity of brain areas across distinct conditions through TMS-evoked potentials (TEPs. Several TEPs have been described, their functional meaning being largely unknown. In particular, short-latency potentials peaking at 5 (P5 and 8 (N8 ms after the TMS pulse have been recently described, but because of their huge amplitude, the problem of whether their origin is cortical or not has been opened. To gain information about these components, we employed a protocol that modulates primary motor cortex excitability (MI through an exclusively cortical phenomena: low frequency stimulation of premotor area (PMC. TMS was applied simultaneously with EEG recording from 70 electrodes. Amplitude of TEPs evoked by 200 single-pulses TMS delivered over MI at 110% of resting motor threshold was measured before and after applying 900 TMS conditioning stimuli to left premotor cortex with 1 Hz repetition rate. Single subject analyses showed reduction in TEPs amplitude after PMC conditioning in a sample of participants and increase in TEPs amplitude in two subjects. No effects were found on corticospinal excitability as recorded by motor evoked potentials (MEPs. Furthermore, correlation analysis showed an inverse relation between the effects of the conditioning protocol on P5-N8 complex amplitude and MEPs amplitude. Because the effects of the used protocol have been ascribed to a cortical interaction between premotor area and MI, we suggest that despite the sign of P5-N8 amplitude modulation is not consistent across participant, this modulation could indicate, at least in part, their cortical origin. We conclude that with an accurate experimental procedure early-latency components can be used to evaluate the reactivity of the stimulated cortex.

  3. Dynamic properties of human visual evoked and omitted stimulus potentials

    Bullock, T.H.; Karamürsel, Sacit; Achimowicz, Jerzy Z.; C., McClune Michael; Canan, Baar-Eroglu


    Visual evoked potentials (VEP) and omitted stimulus potentials (OSPs) are reexamined in scalp recordings from 19 healthy subjects. The principal finding is a distinction in form, latency and properties between OSPs in the conditioning stimulus range 5 Hz, used in previous studies of selected elasmobranchs, teleost fish and reptiles. We cannot find OSPs between 2 and 5 Hz. The high frequency ("fast,"ca. 6 to >40 Hz) and the low frequency ("slow," ca. 0.3-1.6 Hz) OSPs have different forms and l...

  4. Visual evoked potentials to colour change of a moving bar

    Carolina eMurd; Kairi eKreegipuu; Nele eKuldkepp; Aire eRaidvee; Maria eTamm; Jüri eAllik


    In our previous study we found that it takes less time to detect colour change in a moving object compared to colour change in a stationary one (Kreegipuu et al., 2006, Vision Research 46(11), 1848-1855). Here, we replicated the experiment, but in addition to reaction times we measured visual evoked potentials, to see whether this effect of motion is revealed at the cortical level of information processing. We asked our subjects to detect colour changes in stationary (0º/s) and moving bars (4...

  5. Sense Estimation and Instrumental Evaluation of Fabric-Evoked Prickle

    敖利民; 郁崇文


    In this paper, the mechanism of fabric-evoked prickle is discussed, which indicates that the mechanical stimuli aroused by the fiber ends on the fabric surface to the skin-sensory receptors are responsible for prickle. The factors influencing the intensity of prickle are specialized and anatomized. Several means of sense estimate, including the corresponding statistical measures, are described. A few groping objective methods of evaluating prickle are analyzed, including the testing principles, the advantages and the disadvantages. At last, a new concept is proposed on the objective evaluation of prickle.

  6. Brain stem auditory evoked responses in human infants and adults

    Hecox, K.; Galambos, R.


    Brain stem evoked potentials were recorded by conventional scalp electrodes in infants (3 weeks to 3 years of age) and adults. The latency of one of the major response components (wave V) is shown to be a function both of click intensity and the age of the subject; this latency at a given signal strength shortens postnatally to reach the adult value (about 6 msec) by 12 to 18 months of age. The demonstrated reliability and limited variability of these brain stem electrophysiological responses provide the basis for an optimistic estimate of their usefulness as an objective method for assessing hearing in infants and adults.

  7. Clinical application of vestibular evoked myogenic potential (VEMP).

    Murofushi, Toshihisa


    The author reviewed clinical aspects of vestibular evoked myogenic potentials (VEMPs). Now two types of VEMPs are available. The first one is cervical VEMP, which is recorded in the sternocleidomastoid muscle and predominantly reflects sacculo-collic reflex. The other is ocular VEMP, which is usually recorded below the lower eye lid and predominantly reflects utriculo-ocular reflex. VEMPs play important roles not only for assessment of common vestibular diseases but also for establishment of new clinical entities. Clinical application in Meniere's disease, vestibular neuritis, benign paroxysmal positional vertigo, vestibular migraine, idiopathic otolithic vertigo, and central vertigo/dizziness was reviewed. PMID:26791591

  8. Re-feeding evokes reproductive overcompensation of food-restricted Brandt's voles.

    Xie, Xuehui; Wen, Yilei; Niu, Hongxing; Shi, Dazhao; Zhang, Zhibin


    In natural conditions, animals have to cope with fluctuations of food resources. Animals having experienced prolonged decrease in feeding opportunities may increase their reproductive success when meeting abundant food. Though food restriction is well known to reduce reproductive success of animals, it is not clear whether re-feeding can restore or even overcompensate the reproductive success. In this study, we investigated the differences in reproductive parameters between food-restricted and refed (FR-RF) group and control group of Brandt's vole (Lasiopodomys brandtii). For 4 weeks, FR-RF voles were provided with 70% of their normal daily food intake and then they were fed ad libitum for the next 4 weeks. Voles of control group were fed ad libitum for 8 weeks. Females (FR-RF or control) were mated to non-littermate males of the same group (FR-RF or control), and we found that the mean litter size and survival rate of F1 pups of FR-RF group were significantly higher than those of control group. We also provided a field example showing that the litter size of Brandt's voles tended to be higher if they experienced two consecutive dry and wet months than that of voles didn't have this experience. Our results suggest that re-feeding may have evoked an overcompensatory mechanism of food-restricted voles in reproductive success. This may be an adaptive strategy for Brandt's voles (with oscillating populations) to cope with the fluctuating food resources in natural conditions by adjusting their reproductive success. PMID:22019786

  9. Effect of renewed SS-cream on spinal somatosensory evoked potential in rabbits

    LongTian; Zhong-ChengXin; HuaXin; JieFu; Yi-MingYuan; Wu-JiangLiu; ChunYang


    Aim:The effect of a renewed SS-cream (RSSC) on the treatment of premature ejaculation (PE) was evaluated and compared with the original SS-cream (OSSC).Methods: Sixty male white New Zealand rabbits,weighing 2.5kg-3.0kg,were divided at random into 3 groups:the RSSC,OSSC and placebo groups.The spinal somatosensory evoked potential (SSEP) elicited by electric stimulation of the glans penis with disk electrode was investigated with an electrophysiograph (Poseidomn,Shanghai,China) before and 10,30 and 60 min after drug or placebo application on the glans.The Onset and the N1 latencies and the amplitude of SSEP were recorded and analyzed. Results:There was no significant difference (P>0.05) in the mean Onset and N1 latency of SSEP among the 3 groups before drug application.Compared with the pre-application value,the mean Onset and N 1 latencies in the RSSC and OSSC groups were significantly prolonged at 10,30 and 60 min after treatment (P0.05) in the placebo group.The mean Onset latency of RSSC at 10 and 30 min and that of OSSC at 30 min were significantly delayed (P<0.05) compared with the placebo group.The mean N1 latency of RSSC at 30 and 60 min and that of OSSC group at 30 min were also significantly delayed (P<0.05).Conclusion:RSSC delays the latencies of SSEP,suggesting a local desensitizing effect on the sensory receptor of the glans penis dorsal nerve,which provides the potential for PE treatment.The desensitizing effect of RSSC is higher than that of OSSC.( Asian J Androl 2004 Mar;6:15-18)

  10. Selectivity and plasticity in a sound-evoked male-male interaction in Drosophila.

    Jeonghyeon Yoon

    Full Text Available During courtship, many animals, including insects, birds, fish, and mammals, utilize acoustic signals to transmit information about species identity. Although auditory communication is crucial across phyla, the neuronal and physiologic processes are poorly understood. Sound-evoked chaining behavior, a display of homosexual courtship behavior in Drosophila males, has long been used as an excellent model for analyzing auditory behavior responses, outcomes of acoustic perception and higher-order brain functions. Here we developed a new method, termed ChaIN (Chain Index Numerator, in which we use a computer-based auto detection system for chaining behavior. The ChaIN system can systematically detect the chaining behavior induced by a series of modified courtship song playbacks. Two evolutionarily related Drosophila species, Drosophila melanogaster and Drosophila simulans, exhibited dramatic selective increases in chaining behavior when exposed to specific auditory cues, suggesting that auditory discrimination processes are involved in the acceleration of chaining behavior. Prolonged monotonous pulse sounds containing courtship song components also induced high intense chaining behavior. Interestingly, the chaining behavior was gradually suppressed over time when song playback continued. This behavioral change is likely to be a plastic behavior and not a simple sensory adaptation or fatigue, because the suppression was released by applying a different pulse pattern. This behavioral plasticity is not a form of habituation because different modality stimuli did not recover the behavioral suppression. Intriguingly, this plastic behavior partially depended on the cAMP signaling pathway controlled by the rutabaga adenylyl cyclase gene that is important for learning and memory. Taken together, this study demonstrates the selectivity and behavioral kinetics of the sound-induced interacting behavior of Drosophila males, and provides a basis for the

  11. Evaluation of brain stem auditory evoked potentials in stable patients with chronic obstructive pulmonary disease

    Gupta Prem


    Full Text Available Though there are few studies addressing brainstem auditory evoked potentials (BAEP in patients with chronic obstructive pulmonary disease (COPD, subclinical BAEP abnormalities in stable COPD patients have not been studied. The present study aimed to evaluate the BAEP abnormalities in this study group. Materials and Methods : In the present study, 80 male subjects were included: COPD group comprised 40 smokers with stable COPD with no clinical neuropathy; 40 age-matched healthy volunteers served as the control group. Latencies of BAEP waves I, II, III, IV, and V, together with interpeak latencies (IPLs of I-III, I-V, and III-V, and amplitudes of waves I-Ia and V-Va were studied in both the groups to compare the BAEP abnormalities in COPD group; the latter were correlated with patient characteristics and Mini-Mental Status Examination Questionnaire (MMSEQ scores to seek any significant correlation. Results: Twenty-six (65% of the 40 COPD patients had BAEP abnormalities. We observed significantly prolonged latencies of waves I, III, V over left ear and waves III, IV, V over right ear; increased IPLs of I-V, III-V over left ear and of I-III, I-V, III-V over right side. Amplitudes of waves I-Ia and V-Va were decreased bilaterally. Over left ear, the latencies of wave I and III were significantly correlated with FEV 1 ; and amplitude of wave I-Ia, with smoking pack years. A weak positive correlation between amplitude of wave I-Ia and duration of illness; and a weak negative correlation between amplitude of wave V-Va and MMSEQ scores were seen over right side. Conclusions : We observed significant subclinical BAEP abnormalities on electrophysiological evaluation in studied stable COPD male patients having mild-to-moderate airflow obstruction.

  12. Guillain-Barré syndrome in child with prolong intubation

    Ashwin Borade


    Full Text Available Guillain-Barré syndrome (GBS is an acute demyelinating disorder of the peripheral nervous system that results from an aberrant immune response directed at peripheral nerves. A typical GBS patient presents with rapidly ascending symmetrical weakness, which may progress to respiratory failure in 30% of patients. There are no definite criteria exists in GBS in children regarding prolonged ventilation. Here we report a child of GBS requiring prolonged intubation and ventilation for 60 days who afterward had a complete recovery. We present this case to highlight the importance that even in children prolonged intubation and ventilation of GBS case prognosis can be good.

  13. Geometric Approaches for Generating Prolongations for Nonlinear Partial Differential Equations

    Bracken, Paul


    The prolongation structure of a two-by-two problem is formulated very generally in terms of exterior differential forms on a standard representation of Pauli matrices. The differential system is general without making reference to any specific equation. An integrability condition is provided which gives by construction the equation to be investigated and whose components involve the structure constants of an SU(2) Lie algebra. Along side this, a related, different kind of prolongation, a type of Wahlquist-Estabrook prolongation, over a closed differential ideal is discussed and some applications are given.

  14. Differences in brachial and femoral artery responses to prolonged sitting

    Thosar, Saurabh S.; Bielko, Sylvanna L.; Wiggins, Chad C.; Wallace, Janet P


    Introduction It is unknown if there are limb differences in vascular function during prolonged sitting. Purpose This study was designed to test whether the effects of prolonged sitting on brachial artery (BA) and the superficial femoral artery (SFA) are similar. Methods Twelve men (24.2 ± 4 yrs.) participated in a 3 hr prolonged sitting trial (SIT). SFA and BA flow mediated dilation (FMD) and respective flow patterns were measured at baseline, 1 hr, 2 hr and 3 hr. Results By a one-way ANOVA t...

  15. Recording Visual Evoked Potentials and Auditory Evoked P300 at 9.4T Static Magnetic Field

    Arrubla, Jorge; Neuner, Irene; Hahn, David; Boers, Frank; Shah, N J


    Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has shown a number of advantages that make this multimodal technique superior to fMRI alone. The feasibility of recording EEG at ultra-high static magnetic field up to 9.4T was recently demonstrated and promises to be implemented soon in fMRI studies at ultra high magnetic fields. Recording visual evoked potentials are expected to be amongst the most simple for simultaneous EEG/fMRI at ultr...

  16. Optimal stimulus scheduling for active estimation of evoked brain networks

    Kafashan, MohammadMehdi; Ching, ShiNung


    Objective. We consider the problem of optimal probing to learn connections in an evoked dynamic network. Such a network, in which each edge measures an input-output relationship between sites in sensor/actuator-space, is relevant to emerging applications in neural mapping and neural connectivity estimation. Approach. We show that the problem of scheduling nodes to a probe (i.e., stimulate) amounts to a problem of optimal sensor scheduling. Main results. By formulating the evoked network in state-space, we show that the solution to the greedy probing strategy has a convenient form and, under certain conditions, is optimal over a finite horizon. We adopt an expectation maximization technique to update the state-space parameters in an online fashion and demonstrate the efficacy of the overall approach in a series of detailed numerical examples. Significance. The proposed method provides a principled means to actively probe time-varying connections in neuronal networks. The overall method can be implemented in real time and is particularly well-suited to applications in stimulation-based cortical mapping in which the underlying network dynamics are changing over time.

  17. Perceived causality influences brain activity evoked by biological motion.

    Morris, James P; Pelphrey, Kevin A; McCarthy, Gregory


    Using functional magnetic resonance imaging (fMRI), we investigated brain activity in an observer who watched the hand and arm motions of an individual when that individual was, or was not, the cause of the motion. Subjects viewed a realistic animated 3D character who sat at a table containing four pistons. On Intended Motion trials, the character raised his hand and arm upwards. On Unintended Motion trials, the piston under one of the character's hands pushed the hand and arm upward with the same motion. Finally, during Non-Biological Motion control trials, a piston pushed a coffee mug upward in the same smooth motion. Hand and arm motions, regardless of intention, evoked significantly more activity than control trials in a bilateral region that extended ventrally from the posterior superior temporal sulcus (pSTS) region and which was more spatially extensive in the right hemisphere. The left pSTS near the temporal-parietal junction, robustly differentiated between the Intended Motion and Unintended Motion conditions. Here, strong activity was observed for Intended Motion trials, while Unintended Motion trials evoked similar activity as the coffee mug trials. Our results demonstrate a strong hemispheric bias in the role of the pSTS in the perception of causality of biological motion. PMID:18633843

  18. Dorsomedial hypothalamus mediates autonomic, neuroendocrine, and locomotor responses evoked from the medial preoptic area

    Hunt, Joseph L.; Zaretsky, Dmitry V.; Sarkar, Sumit; DiMicco, Joseph A.


    Previous studies suggest that sympathetic responses evoked from the preoptic area in anesthetized rats require activation of neurons in the dorsomedial hypothalamus. Disinhibition of neurons in the dorsomedial hypothalamus in conscious rats produces physiological and behavioral changes resembling those evoked by microinjection of muscimol, a GABAA receptor agonist and neuronal inhibitor, into the medial preoptic area. We tested the hypothesis that all of these effects evoked from the medial p...

  19. Similar itch and nociceptive sensations evoked by punctate cutaneous application of capsaicin, histamine and cowhage

    Sikand, Parul; Shimada, Steven G.; Green, Barry G.; LaMotte, Robert H.


    Itch evoked by cowhage or histamine is reduced or blocked by capsaicin desensitization, suggesting that pruriceptive neurons are capsaicin-sensitive. Topical capsaicin can evoke both nociceptive sensations and itch, whereas intradermal injection of capsaicin evokes only burning pain. To dissociate the pruritic and nociceptive sensory effects caused by the chemical activation of sensory neurons, chemicals were applied in a punctiform manner to the skin of the forearm using individual, heat-ina...

  20. Control of cerebellar granule cell output by sensory-evoked Golgi cell inhibition

    Duguid, Ian; BRANCO, Tiago; Chadderton, Paul; Arlt, Charlotte; Powell, Kate; Häusser, Michael


    Understanding how synaptic inhibition regulates sensory responses is a fundamental question in neuroscience. In cerebellar granule cells, sensory stimulation is thought to evoke an excitation–inhibition sequence driven by direct input from mossy fibers and followed by classical disynaptic feed-forward inhibition from nearby Golgi cells. We made, to our knowledge, the first voltage-clamp recordings of sensory-evoked inhibition in granule cells in vivo and show that, surprisingly, sensory-evoke...

  1. Relationships between Electrically Evoked Potentials and Loudness Growth in Bilateral Cochlear Implant Users

    Kirby, Benjamin; Brown, Carolyn; Abbas, Paul; Etler, Christine; O’Brien, Sara


    Bilateral cochlear implantation has motivated efforts to ensure that sounds presented at equal levels to each ear are perceived as equally loud. Psychophysical loudness balancing is not always practical, especially with pediatric users. Electrophysiological potentials -- electrically evoked auditory brain stem response (EABR) and electrically evoked compound action potential (ECAP) measures -- may provide a means of approximating loudness balance. It was hypothesized that stimuli evoking equa...

  2. Image color transfer to evoke different emotions based on color combinations

    He, Li; Qi, Hairong; Zaretzki, Russell


    In this paper, a color transfer framework to evoke different emotions for images based on color combinations is proposed. The purpose of this color transfer is to change the "look and feel" of images, i.e., evoking different emotions. Colors are confirmed as the most attractive factor in images. In addition, various studies in both art and science areas have concluded that other than single color, color combinations are necessary to evoke specific emotions. Therefore, we propose a novel frame...

  3. Chemo May Prolong Lives of Some Brain Cancer Patients

    ... 158167.html Chemo May Prolong Lives of Some Brain Cancer Patients: Study Those with slow-growing gliomas lived ... States, nearly 23,000 adults were diagnosed with brain cancer in 2015, according to the U.S. National Cancer ...


    Galimberti R; Kowalczuk A; Luque K,; Musso C; Enz P; Algranati L


    SUMMARYSecondary hyperparathyroidism is one of the main deragements caused by chronic renal failure, and parathyroid hormone is considered one of the toxins of the uremic syndrome. Prolonged fever due to primary hyperparathyroidism have already been described in the literature but not yet as induced by secondary hyperparathyroidism. In this case report a patient suffering from an erythema nodosum and prolonged fever associated to secondary hyperparathyroidism that disappeared through subtotal...

  5. Geometric Approaches for Generating Prolongations for Nonlinear Partial Differential Equations

    Bracken, Paul


    The prolongation structure of a two-by-two problem is formulated very generally in terms of exterior differential forms on a standard representation of Pauli matrices. The differential system is general without making reference to any specific equation. An integrability condition is provided which gives by construction the equation to be investigated and whose components involve the structure constants of an SU(2) Lie algebra. Along side this, a related, different kind of prolongation, a type...

  6. Prolonged QTc Interval and Torsades de Pointes Induced by Citalopram

    Deshmukh, Anand; Ulveling, Kyle; Alla, Venkata; Abuissa, Hussam; Airey, Kelly


    Citalopram is a selective serotonin reuptake inhibitor with a favorable cardiac-safety profile. Corrected QT interval (QTc) prolongation and cardiac arrhythmias have not been previously reported in association with citalopram use except in the presence of overdose, abnormal electrolyte values, or renal or liver failure. Herein, we report the case of a 40-year-old woman with mental depression who presented with a prolonged QTc interval and torsades de pointes after the initiation of citalopram...

  7. Factors predicting prolonged empirical antifungal treatment in critically ill patients

    Zein, Mohamed; Parmentier-Decrucq, Erika; Kalaoun, Amer; Bouton, Olivier; Wallyn, Frédéric; Baranzelli, Anne; Elmanser, Dia; Sendid, Boualem; Nseir, Saad


    Objective To determine the incidence, risk factors, and impact on outcome of prolonged empirical antifungal treatment in ICU patients. Methods Retrospective observational study performed during a one-year period. Patients who stayed in the ICU >48 h, and received empirical antifungal treatment were included. Patients with confirmed invasive fungal disease were excluded. Prolonged antifungal treatment was defined as percentage of days in the ICU with antifungals > median percentage in the whol...

  8. Event-related evoked potentials in chronic respiratory encephalopathy

    Zaidan, Radwan


    A R Al Tahan1, R Zaidan1, S Jones2, A Husain3, A Mobeireek1, A Bahammam11Department of Medicine, 3Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 2Department of Neurophysiology, Institute of Neurology, London, UKBackground: Cognitive event-related potential (P300) is an index of cognitive processing time. It was found to be prolonged in dementia, renal, and hepatic encephalopathies, but was not extensively assessed in respiratory failure.Objective: T...

  9. The Distribution of Etiology in Newborns with Prolonged Jaundice

    Merih Çetinkaya


    Full Text Available Aim: The aim of this study is to determine the etiology in neonates admitted with prolonged jaundice.Materials and Method: Neonates with prolonged jaundice were included to this prospective study designed between January 2007 and December 2007. Prolonged jaundice was defined as total bilirubin level >5 mg/dL in newborns older than 14 days of age. After detailed history and physical examination, blood tests including blood groups of baby and mother, total, direct and indirect bilirubin, complete blood count (CBC, blood smear, reticulocyte count, Coombs test, serum aspartat transaminase (AST level, serum alanin transaminase (ALT level, viral markers, thyroid function tests, and glucose-6 phosphate dehydrogenase (G-6 PD level and routine urine analysis with urine culture were performed in all newborns. Results: A total of 154 neonates were enrolled to the study. The most frequent cause of prolonged jaundice was breast milk jaundice (53%. It was followed by urinary tract infections and clinical sepsis (29%, hemolytic causes due to blood group incompetency (10% and congenital hypothyroidism (8%. However,there were no significant differences between etiology and mean bilirubin levels.Conclusion: It is important to determine the etiology and to plan therapy according to etiology is important in newborns with prolonged jaundice. Breast milk jaundice, urinary tract infection and sepsis, hypothyroidism and hemolytic causes must be considered as the main etiology in newborns with prolonged jaundice. (Journal of Current Pediatrics 2008; 6: 99-103

  10. Electrical Circuit Modeling for Somatosensory Evoked Fields in Magnetoencephalogram

    Ishihara, Shinichi; Tanaka, Keita; Uchikawa, Yoshinori; Kobayashi, Koichiro

    We measured somatosensory evoked fields (SEFs) by applying on electric stimulus to the right finger (medium nerve and ulnar nerve) and the right ankle (posterior tibial nerve) with a 39-channel SQUID system, which can measure magnetic-field components perpendicular (Br) and tangential to the scalp (Bθ, Bφ) simultaneously. To investigate the relationship between phase lag and stimulus repetition frequency (SRF), the delay time of a component synchronized with the SRFs was calculated by convoluting the reference signal and the measured SEF. The phase lag was linear to SRF for at least three different ranges of the SRFs in each SEF data. We simulated the SEF responses based on the results of phase-lag characteristics and determined the parameters for modeling. To quantitatively characterize the component of SEF, we proposed electric circuit model for the characteristics of phase-lag of the SEF with stimuli frequency.

  11. Vestibular myogenic and acoustical brainstem evoked potentials in neurological practice

    O. S. Korepina


    Full Text Available Along with the inspection of acoustical cortex and brainstem EP in neurologic, otoneurologic and audiologic practice recently start to use so-called vestibular evoked myogenic potentials (VEMP. It is shown, that at ear stimulation by a loud sound and record of sterno-cleidomastoid contraction is possible to estimate function of the inferior vestibular nerve and vestibulospinal pathways, a sacculo-cervical reflex. In article some methodical and clinical questions of application of these kinds are presented. Combine research acoustic brainstem EP and VEMP allows to confirm effectively lesions of acoustical and vestibular ways at brainstem. The conclusion becomes, that this kind of inspection is important for revealing demielinisation and defeats in vestibulospinal tract, that quite often happens at MS, and at estimation of efficiency of treatment

  12. Suicide attempts, platelet monoamine oxidase and the average evoked response

    The relationship between suicides and suicide attempts and two biological measures, platelet monoamine oxidase levels (MAO) and average evoked response (AER) augmenting was examined in 79 off-medication psychiatric patients and in 68 college student volunteers chosen from the upper and lower deciles of MAO activity levels. In the patient sample, male individuals with low MAO and AER augmenting, a pattern previously associated with bipolar affective disorders, showed a significantly increased incidence of suicide attempts in comparison with either non-augmenting low MAO or high MAO patients. Within the normal volunteer group, all male low MAO probands with a family history of suicide or suicide attempts were AER augmenters themselves. Four completed suicides were found among relatives of low MAO probands whereas no high MAO proband had a relative who committed suicide. These findings suggest that the combination of low platelet MAO activity and AER augmenting may be associated with a possible genetic vulnerability to psychiatric disorders. (author)

  13. Temporal suppression and augmentation of click-evoked otoacoustic emissions

    Verhulst, Sarah; Harte, James; Dau, Torsten


    This study investigates and models temporal suppression of click-evoked otoacoustic emissions (CEOAEs). This suppression-effect is created when a suppressor-click is presented close in time to a test-click. The analysis was carried out for short time-frames of short- and long-latency CEOAEs. The...... latter is defined as a CEOAE with duration greater than 20 ms, typically observed for test subjects with spontaneous otoacoustic emissions (SOAEs). Previous studies have tended to exclude these test subjects but they are incorporated here. The results from six exemplary subjects demonstrate that temporal...... temporal suppression and augmentation of CEOAEs. Recently, a feedback automatic gain control (AGC) system has been used to model CEOAE suppression. However, this system cannot account for augmentation and therefore another, dynamic nonlinear model was developed. Suppression and augmentation were modeled...

  14. Auditory evoked field measurement using magneto-impedance sensors

    Wang, K., E-mail:; Tajima, S.; Song, D.; Uchiyama, T. [Graduate School of Engineering, Nagoya University, Nagoya (Japan); Hamada, N.; Cai, C. [Aichi Steel Corporation, Tokai (Japan)


    The magnetic field of the human brain is extremely weak, and it is mostly measured and monitored in the magnetoencephalography method using superconducting quantum interference devices. In this study, in order to measure the weak magnetic field of the brain, we constructed a Magneto-Impedance sensor (MI sensor) system that can cancel out the background noise without any magnetic shield. Based on our previous studies of brain wave measurements, we used two MI sensors in this system for monitoring both cerebral hemispheres. In this study, we recorded and compared the auditory evoked field signals of the subject, including the N100 (or N1) and the P300 (or P3) brain waves. The results suggest that the MI sensor can be applied to brain activity measurement.

  15. Auditory evoked field measurement using magneto-impedance sensors

    The magnetic field of the human brain is extremely weak, and it is mostly measured and monitored in the magnetoencephalography method using superconducting quantum interference devices. In this study, in order to measure the weak magnetic field of the brain, we constructed a Magneto-Impedance sensor (MI sensor) system that can cancel out the background noise without any magnetic shield. Based on our previous studies of brain wave measurements, we used two MI sensors in this system for monitoring both cerebral hemispheres. In this study, we recorded and compared the auditory evoked field signals of the subject, including the N100 (or N1) and the P300 (or P3) brain waves. The results suggest that the MI sensor can be applied to brain activity measurement

  16. Source localization of auditory evoked potentials after cochlear implantation.

    Debener, Stefan; Hine, Jemma; Bleeck, Stefan; Eyles, Julie


    Little is known about how the auditory cortex adapts to artificial input as provided by a cochlear implant (CI). We report the case of a 71-year-old profoundly deaf man, who has successfully used a unilateral CI for 4 years. Independent component analysis (ICA) of 61-channel EEG recordings could separate CI-related artifacts from auditory-evoked potentials (AEPs), even though it was the perfectly time-locked CI stimulation that caused the AEPs. AEP dipole source localization revealed contralaterally larger amplitudes in the P1-N1 range, similar to normal hearing individuals. In contrast to normal hearing individuals, the man with the CI showed a 20-ms shorter N1 latency ipsilaterally. We conclude that ICA allows the detailed study of AEPs in CI users. PMID:17910729

  17. Light-evoked S-nitrosylation in the retina.

    Tooker, Ryan E; Vigh, Jozsef


    Nitric oxide (NO) synthesis in the retina is triggered by light stimulation. NO has been shown to modulate visual signal processing at multiple sites in the vertebrate retina, via activation of the most sensitive target of NO signaling, soluble guanylate cyclase. NO can also alter protein structure and function and exert biological effects directly by binding to free thiol groups of cysteine residues in a chemical reaction called S-nitrosylation. However, in the central nervous system, including the retina, this reaction has not been considered to be significant under physiological conditions. Here we provide immunohistochemical evidence for extensive S-nitrosylation that takes place in the goldfish and mouse retinas under physiologically relevant light intensities, in an intensity-dependent manner, with a strikingly similar pattern in both species. Pretreatment with N-ethylmaleimide (NEM), which occludes S-nitrosylation, or with 1-(2-trifluromethylphenyl)imidazole (TRIM), an inhibitor of neuronal NO synthase, eliminated the light-evoked increase in S-nitrosylated protein immunofluorescence (SNI) in the retinas of both species. Similarly, light did not increase SNI, above basal levels, in retinas of transgenic mice lacking neuronal NO synthase. Qualitative analysis of the light-adapted mouse retina with mass spectrometry revealed more than 300 proteins that were S-nitrosylated upon illumination, many of which are known to participate directly in retinal signal processing. Our data strongly suggest that in the retina light-evoked NO production leads to extensive S-nitrosylation and that this process is a significant posttranslational modification affecting a wide range of proteins under physiological conditions. PMID:25823749

  18. Can Treadmill Perturbations Evoke Stretch Reflexes in the Calf Muscles?

    Lizeth H Sloot

    Full Text Available Disinhibition of reflexes is a problem amongst spastic patients, for it limits a smooth and efficient execution of motor functions during gait. Treadmill belt accelerations may potentially be used to measure reflexes during walking, i.e. by dorsal flexing the ankle and stretching the calf muscles, while decelerations show the modulation of reflexes during a reduction of sensory feedback. The aim of the current study was to examine if belt accelerations and decelerations of different intensities applied during the stance phase of treadmill walking can evoke reflexes in the gastrocnemius, soleus and tibialis anterior in healthy subjects. Muscle electromyography and joint kinematics were measured in 10 subjects. To determine whether stretch reflexes occurred, we assessed modelled musculo-tendon length and stretch velocity, the amount of muscle activity, as well as the incidence of bursts or depressions in muscle activity with their time delays, and co-contraction between agonist and antagonist muscle. Although the effect on the ankle angle was small with 2.8±1.0°, the perturbations caused clear changes in muscle length and stretch velocity relative to unperturbed walking. Stretched muscles showed an increasing incidence of bursts in muscle activity, which occurred after a reasonable electrophysiological time delay (163-191 ms. Their amplitude was related to the muscle stretch velocity and not related to co-contraction of the antagonist muscle. These effects increased with perturbation intensity. Shortened muscles showed opposite effects, with a depression in muscle activity of the calf muscles. The perturbations only slightly affected the spatio-temporal parameters, indicating that normal walking was retained. Thus, our findings showed that treadmill perturbations can evoke reflexes in the calf muscles and tibialis anterior. This comprehensive study could form the basis for clinical implementation of treadmill perturbations to functionally

  19. From prolonging life to prolonging working life: Tackling unemployment among liver-transplant recipients.

    Åberg, Fredrik


    Return to active and productive life is a key goal of modern liver transplantation (LT). Despite marked improvements in quality of life and functional status, a substantial proportion of LT recipients are unable to resume gainful employment. Unemployment forms a threat to physical and psychosocial health, and impairs LT cost-utility through lost productivity. In studies published after year 2000, the average post-LT employment rate is 37%, ranging from 22% to 55% by study. Significant heterogeneity exists among studies. Nonetheless, these employment rates are lower than in the general population and kidney-transplant population. Most consistent employment predictors include pre-LT employment status, male gender, functional/health status, and subjective work ability. Work ability is impaired by physical fatigue and depression, but affected also by working conditions and society. Promotion of post-LT employment is hampered by a lack of interventional studies. Prevention of pre-LT disability by effective treatment of (minimal) hepatic encephalopathy, maintaining mobility, and planning work adjustments early in the course of chronic liver disease, as well as timely post-LT physical rehabilitation, continuous encouragement, self-efficacy improvements, and depression management are key elements of successful employment-promoting strategies. Prolonging LT recipients' working life would further strengthen the success of transplantation, and this is likely best achieved through multidisciplinary efforts ideally starting even before LT candidacy. PMID:27076755

  20. Comparison of visual evoked potentials and retinal nerve fibre layer thickness in Alzheimer‘s disease



    We demonstrated that pattern visual evoked potentials did not show any significant correlation despite subtle loss in retinal nerve fibre layer thickness. It remains open whether additional flash visual evoked potentials combined with retinal nerve fibre layer thickness analysis may be useful in diagnosing Alzheimer‘s disease, particularly for mild-to-moderate stages of the disease.

  1. A simple model for the generation of the vestibular evoked myogenic potential (VEMP)

    Wit, HP; Kingma, CM


    Objective: To describe the mechanism by which the vestibular evoked myogenic potential is generated. Methods: Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long

  2. The effect of changes in perilymphatic K+ on the vestibular evoked potential in the guinea pig

    Kingma, C. M.; Wit, H. P.


    To investigate the effect on the functioning of the vestibular system of a rupture of Reissner's membrane, artificial endolymph was injected in scala media of ten guinea pigs and vestibular evoked potentials (VsEPs), evoked by vertical acceleration pulses, were measured. Directly after injection of

  3. Sex and Ear Differences in Spontaneous and Click-Evoked Otoacoustic Emissions in Young Adults

    Snihur, Adrian W. K.; Hampson, Elizabeth


    Effects of sex and handedness on the production of spontaneous and click-evoked otoacoustic emissions (OAEs) were explored in a non-hearing impaired population (ages 17-25 years). A sex difference in OAEs, either produced spontaneously (spontaneous OAEs or SOAEs) or in response to auditory stimuli (click-evoked OAEs or CEOAEs) has been reported in…

  4. Gender differences in rival characteristics that evoke jealousy in response to emotional versus sexual infidelity

    Buunk, Abraham (Bram); Dijkstra, Pieternel


    Previous research has shown that in men jealousy is evoked more by a rival's status-related characteristics than in women, whereas in women jealousy is evoked more by a rival's physical attractiveness than in men. The present study examined whether the occurrence of this gender difference depends up

  5. Control of interfaces in Al-C fibre composites

    Warrier, S. G.; Blue, C. A.; Lin, R. Y.


    The interface of Al-C fiber composite was modified by coating a silver layer on the surface of carbon fibres prior to making composites, in an attempt to improve the wettability between molten aluminum and carbon fibers during infiltration. An electroless plating technique was adopted and perfected to provide a homogeneous silver coating on the carbon fiber surface. Al-C fiber composites were prepared using a liquid infiltration technique in a vacuum. It was found that silver coating promoted the wetting between aluminum and carbon fibers, particularly with polyacrylonitrile-base carbon fibers. However, due to rapid dissolution of silver in molten aluminum, it was believed that the improved infiltration was not due to the wetting behavior between molten aluminum and silver. The cleaning of the fiber surface and the preservation of the cleaned carbon surface with silver coating was considered to be the prime reason for the improved wettability. Interfacial reactions between aluminum and carbon fibers were observed. Amorphous carbon was found to react more with aluminum than graphitic carbon. This is believed to be because of the inertness of the graphitic basal planes.

  6. The involuntary nature of music-evoked autobiographical memories in Alzheimer's disease.

    El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe


    The main objective of this paper was to examine the involuntary nature of music-evoked autobiographical memories. For this purpose, young adults, older adults, and patients with a clinical diagnosis of probable Alzheimer's disease (AD) were asked to remember autobiographical events in two conditions: after being exposed to their own chosen music, and in silence. Compared to memories evoked in silence, memories evoked in the "Music" condition were found to be more specific, accompanied by more emotional content and impact on mood, and retrieved faster. In addition, these memories engaged less executive processes. Thus, with all these characteristics and the fact that they are activated by a perceptual cue (i.e., music), music-evoked autobiographic memories have all the features to be considered as involuntary memories. Our paper reveals several characteristics of music-evoked autobiographical memories in AD patients and offers a theoretical background for this phenomenon. PMID:22265372

  7. Is Favorable Outcome Possible After Prolonged Refractory Status Epilepticus?

    Alvarez, Vincent; Drislane, Frank W


    When status epilepticus (SE) remains refractory to appropriate therapy, it is associated with high mortality and with substantial morbidity in survivors. Many outcome predictors such as age, seizure type, level of consciousness before treatment, and mostly, etiology, are well-established. A longer duration of SE is often associated with worse outcome, but duration may lose its prognostic value after several hours. Several terms and definitions have been used to describe prolonged, refractory SE, including "malignant SE," "prolonged" SE, and more recently, "super refractory" SE, defined as "SE that has continued or recurred despite 24 hours of general anesthesia (or coma-inducing anticonvulsants)." There are few data available regarding the outcome of prolonged refractory SE, and even fewer for SE remaining refractory to anesthetic drugs. This article reviews reports of outcome after prolonged, refractory, and "super refractory" SE. Most information detailing the clinical outcome of patients surviving these severe illnesses, in which seizures can persist for days or weeks (and especially those concerning "super-refractory" SE) come from case reports and retrospective cohort studies. In many series, prolonged, refractory SE has a mortality of 30% to 50%, and several studies indicate that most survivors have a substantial decline in functional status. Nevertheless, several reports demonstrate that good functional outcome is possible even after several days of SE and coma induction. Treatment of refractory SE should not be withdrawn from younger patients without structural brain damage at presentation solely because of the duration of SE. PMID:26840875

  8. Severe postpartum sepsis with prolonged myocardial dysfunction: a case report

    Chen Katherine T


    Full Text Available Abstract Introduction Severe sepsis during pregnancy or in the postpartum period is a rare clinical event. In non obstetric surviving patients, the cardiovascular changes seen in sepsis and septic shock are fully reversible five to ten days after their onset. We report a case of septic myocardial dysfunction lasting longer than ten days. To the best of our knowledge, this is the first report of prolonged septic myocardial dysfunction in a parturient. Case presentation A 24 year old Hispanic woman with no previous medical history developed pyelonephritis and severe sepsis with prolonged myocardial dysfunction after a normal spontaneous vaginal delivery. Conclusions Septic myocardial dysfunction may be prolonged in parturients requiring longer term follow up and pharmacologic treatment.

  9. Nucleic acid therapy for lifespan prolongation: Present and future

    Wing-Fu Lai


    Lifespan prolongation is a common desire of the human race. With advances in biotechnology, the mechanism of aging has been gradually unraveled, laying the theoretical basis of nucleic acid therapy for lifespan prolongation. Regretfully, clinically applicable interventions do not exist without the efforts of converting theory into action, and it is the latter that has been far from adequately addressed at the moment. This was demonstrated by a database search on PubMed and Web of Science, from which only seven studies published between 2000 and 2010 were found to directly touch on the development of nucleic acid therapy for anti-aging and/or longevity enhancing purposes. In light of this, the objective of this article is to overview the current understanding of the intimate association between genes and longevity, and to bring the prospect of nucleic acid therapy for lifespan prolongation to light.

  10. Comparison of sensitivity of magnetic resonance imaging and evoked potentials in the detection of brainstem involvement in multiple sclerosis

    A comparison was made of the sensitivity of magnetic resonance imaging and the combined use of Brainstem Auditory Evoked Potential and Median Somatosensory Evoked Potential in the detection of brainstem dysfunction in 54 multiple sclerosis patients. 10 refs.; 2 tabs

  11. QTc-prolonging drugs and hospitalizations for cardiac arrhythmias

    De Bruin, Marie L; Hoes, Arno W; Leufkens, Hubert G M


    Cardiac arrhythmia as an adverse effect of noncardiac drugs has been an issue of growing importance during the past few years. In this population-based study, we evaluated the risk for serious cardiac arrhythmias during the use of several noncardiac QTc-prolonging drugs in day-to-day practice, and...... use of QTc-prolonging drugs. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate conditional logistic regression, adjusting for potential confounding factors. Data were obtained from the PHARMO record linkage system. We identified 501 cases, 39 of whom used QTc...

  12. Assessing QT interval prolongation and its associated risks with antipsychotics

    Nielsen, Jimmi; Graff, Claus; Kanters, Jørgen K.;


    heart, illustrated as a prolongation of the QT interval on a surface ECG. SCD in individuals receiving antipsychotics has an incidence of approximately 15 cases per 10,000 years of drug exposure but the exact association with TdP remains unknown because the diagnosis of TdP is uncertain. Most patients...... other surrogate markers for TdP have been developed but none of them is clinically implemented yet and QT interval prolongation is still considered the most valid surrogate marker. Although automated QT interval determination may offer some assistance, QT interval determination is best performed by a...

  13. Analysis of brain-stem auditory evoked potential and visual evoked potential in patients with Parkinson disease

    Qiaorong Deng; Jianzhong Deng; Yanmin Zhao; Xiaohai Yan; Pin Chen


    BACKGROUND: With the development of neuroelectrophysiology, it had been identified that all kinds of evoked potentials might reflect the functional status of corresponding pathway. Evoked potentials recruited in the re search of PD, it can be known whether other functional pathway of nervous system is impaired. OBJECTIVE: To observe whether brainstem auditory and visual passageway are impaired in patients with Parkinson disease (PD), and compare with non-PD patients concurrently. DESIGN: A non-randomized concurrent controlled observation. SETTINGS: Henan Provincial Tumor Hospital; Anyang District Hospital. PARTICIPANTS: Thirty-two cases of PD outpatients and inpatients, who registered in the Department of Neurology, Anyang District Hospital from October 1997 to February 2006, were enrolled as the PD group, including 20 males and 12 females, aged 50-72 years old. Inclusive criteria: In accordance with the diagnostic criteria of PD recommended by the dyskinesia and PD group of neurology branch of Chinese Medical Association. Patients with diseases that could cause Parkinson syndrome were excluded by CT scanning or MRI examination. Meanwhile, 30 cases with non-neurological disease were selected from the Department of Internal Medicine of our hospital as the control group, including 19 males and 11 females, aged 45-70 years old. Including criteria: Without history of neurological disease or psychiatric disease; showing normal image on CT. And PD, Parkinson syndrome and Parkinsonism-plus were excluded by professional neurologist. All the patients were informed and agreed with the examination and clinical observation. METHODS: The electrophysiological examination and clinical observation of the PD patients and controls were conducted. The Reporter type 4-channel evoked potential machine (Italy) was used to check brain-stem auditory evoked potential (BAEP) and visual evoked potential (VEP). Why to be examined was explained to test taker. BAEP recording electrode was plac

  14. The effect of lead on brainstem auditory evoked potentials in children

    邹朝春; 赵正言; 唐兰芳; 陈志敏; 杜立中


    Objective To determine whether lead affects brainstem auditory evoked potentials (BAEPs) in low-to-moderate lead exposed children. Methods BAEPs were recorded from 114 asymptomatic children aged 1-6 years. Average values were calculated for peak latency (PL) and amplitude (Amp). Whole blood lead (PbB) levels were assessed by graphite furnace atomic absorption spectroscopy. Based on their PbB levels, subjects were divided into low lead (PbB<100 μg/L) and high lead subgroups (PbB ≥100 μg/L). Results The PbB levels of the 114 subjects ranged from 32.0 to 380.0 μg/L in a positively skewed distribution. The median of PbB levels was 90.0 μg/L while the arithmetic average was 88.0 μg/L. Of the subjects, 43.0% (49/114) had levels equal to or greater than 100 μg/L. Bilateral PLs Ⅰ, Ⅴ, and Ⅲ of the left ear in the high lead subgroup were significantly longer than those in the low lead subgroup (P<0.05). A positive correlation was found between PbB levels and bilateral PLs Ⅰ, Ⅴ and Ⅲ of the left ear (P<0.05), after controlling for age and gender as confounding factors. A significant and positive correlation between PbB levels and PL Ⅰ of the left ear, even when PbB levels were lower than 100 μg/L, in the low subgroup (r=0.295, P=0.019) was also found.Conclusions Lead poisoning in children younger than 6 years old is a very serious problem to which close attention should be paid. The indications that lead prolongs partial PLs may imply that lead, even at PbB levels lower than 100 μg/L, impairs both the peripheral and the central portions of the auditory system. BAEPs may be a sensitive detector of subclinical lead exposure effects on the nervous system in children.

  15. The Effect of Magnesium on Visual Evoked Potentials in L-NAME-Induced Hypertensive Rats.

    Ozsoy, Ozlem; Aras, Sinem; Ulker Karadamar, Pinar; Nasircilar Ulker, Seher; Kocer, Gunnur; Senturk, Umit Kemal; Basrali, Filiz; Yargicoglu, Piraye; Ozyurt, Dilek; Agar, Aysel


    In the literature, although there are many studies regarding complications of hypertension, information concerning its influence on visual evoked potentials (VEPs) is limited. This study aims to clarify the possible therapeutic effects of the preferential magnesium (Mg) treatment on VEPs in an experimental hypertension model. Rats were divided into four groups as follows: control, Mg treated (Mg), N(omega)-nitro-L-arginine methyl ester (L-NAME) hypertension, and L-NAME hypertension + Mg treated (L-NAME + Mg). Hypertension was induced by L-NAME which was given to rats orally over 6 weeks (25 mg/kg/day in drinking water). A magnesium-enriched diet (0.8 g/kg) was given to treatment groups for 6 weeks. Systolic blood pressure (SBP) was determined by using the tail-cuff method. Flash VEPs were recorded. Our results revealed that the SBP was significantly increased in the L-NAME group compared to control. Magnesium treatment significantly attenuated SBP in the hypertensive rats compared to the L-NAME group. The mean latencies of P1, N1, P2, N2, and P3 components were significantly prolonged in hypertensive rats compared to control. Treatment with Mg provided a significant decrease in the latencies of P1, N1, P2, N2, and P3 potentials in the L-NAME + Mg group compared to the L-NAME group. Plasma Mg levels were increased in the L-NAME + Mg group compared to the L-NAME group. No change was detected in the Mg levels of the brains in all experimental groups. Magnesium treatment had no effect on the brain nitrate/nitrite and thiobarbituric acid-reactive substances (TBARS) levels in hypertensive rats compared to non-treated rats. There was a positive correlation between the brain TBARS levels and SBP of the rats. The present study suggests that Mg supplementation has the potential to prevent VEP changes in the L-NAME-induced hypertension model. PMID:26701333

  16. Neurofeedback Effects on Evoked and Induced EEG Gamma Band Reactivity to Drug-related Cues in Cocaine Addiction

    Horrell, Timothy; El-Baz, Ayman; Baruth, Joshua; Tasman, Allan; Sokhadze, Guela; Stewart, Christopher; Sokhadze, Estate


    Introduction Preoccupation with drug and drug-related items is a typical characteristic of cocaine addicted individuals. It has been shown in multiple accounts that prolonged drug use has a profound effect on the EEG recordings of drug addicts when compared to controls during cue reactivity tests. Cue reactivity refers to a phenomenon in which individuals with a history of drug abuse exhibit excessive psychophysiological responses to cues associated with their drug of choice. One of the aims of this pilot study was to determine the presence of an attentional bias to preferentially process drug-related cues using evoked and induced gamma reactivity measures in cocaine addicts before and after biobehavioral treatment based on neurofeedback. Another aim was to show that central SMR amplitude increase and frontal theta control is possible in an experimental outpatient drug users group over 12 neurofeedback sessions. Method Ten current cocaine abusers participated in this pilot research study using neurofeedback combined with Motivational Interviewing sessions. Eight of them completed all planned pre- and post –neurofeedback cue reactivity tests with event-related EEG recording and clinical evaluations. Cue reactivity test represented a visual oddball task with images from the International Affective Picture System and drug-related pictures. Evoked and induced gamma responses to target and non-target drug cues were analyzed using wavelet analysis. Results Outpatient subjects with cocaine addiction completed the biobehavioral intervention and successfully increased SMR while keeping theta practically unchanged in 12 sessions of neurofeedback training. The addition of Motivational Interviewing helped retain patients in the study. Clinical evaluations immediately after completion of the treatment showed decreased self-reports on depression and stress scores, and urine tests collaborated reports of decreased use of cocaine and marijuana. Effects of neurofeedback resulted

  17. Neuroimaging evidence of altered fronto-cortical and striatal function after prolonged cocaine self-administration in the rat.

    Gozzi, Alessandro; Tessari, Michela; Dacome, Lisa; Agosta, Federica; Lepore, Stefano; Lanzoni, Anna; Cristofori, Patrizia; Pich, Emilio M; Corsi, Mauro; Bifone, Angelo


    Cocaine addiction is often modeled in experimental paradigms where rodents learn to self-administer (SA) the drug. However, the extent to which these models replicate the functional alterations observed in clinical neuroimaging studies of cocaine addiction remains unknown. We used magnetic resonance imaging (MRI) to assess basal and evoked brain function in rats subjected to a prolonged, extended-access cocaine SA scheme. Specifically, we measured basal cerebral blood volume (bCBV), an established correlate of basal metabolism, and assessed the reactivity of the dopaminergic system by mapping the pharmacological MRI (phMRI) response evoked by the dopamine-releaser amphetamine. Cocaine-exposed subjects exhibited reduced bCBV in fronto-cortical areas, nucleus accumbens, ventral hippocampus, and thalamus. The cocaine group also showed an attenuated functional response to amphetamine in ventrostriatal areas, an effect that was significantly correlated with total cocaine intake. An inverse relationship between bCBV in the reticular thalamus and the frontal response elicited by amphetamine was found in control subjects but not in the cocaine group, suggesting that the inhibitory interplay within this attentional circuit may be compromised by the drug. Importantly, histopathological analysis did not reveal significant alterations of the microvascular bed in the brain of cocaine-exposed subjects, suggesting that the imaging findings cannot be merely ascribed to cocaine-induced vascular damage. These results document that chronic, extended-access cocaine SA in the rat produces focal fronto-cortical and striatal alterations that serve as plausible neurobiological substrate for the behavioral expression of compulsive drug intake in laboratory animals. PMID:21775976

  18. Vestibular evoked myogenic potentials (VEMPs) in central neurological disorders.

    Venhovens, J; Meulstee, J; Verhagen, W I M


    Several types of acoustic stimulation (i.e. tone bursts or clicks), bone-conducted vibration, forehead taps, and galvanic stimulation elicit myogenic potentials. These can be recorded in cervical and ocular muscles, the so called vestibular evoked myogenic potentials (VEMPs). The cervical VEMP (cVEMP) resembles the vestibulo-collic reflex and the responses can be recorded from the ipsilateral sternocleidomastoid muscle. The ocular VEMP resembles the vestibulo-ocular reflex and can be recorded from extra-ocular muscles by a surface electrode beneath the contralateral infraorbital margin. Initially, the literature concerning VEMPs was limited to peripheral vestibular disorders, however, the field of VEMP testing is rapidly expanding, with an increasing focus on central neurological disorders. The current literature concerning VEMP abnormalities in central neurological disorders is critically reviewed, especially regarding the methodological aspects in relation to quality as well as the clinical interpretation of the VEMP results. Suggestions for further research are proposed as well as some clinically useful indications. PMID:25649969

  19. A Subspace Method for Dynamical Estimation of Evoked Potentials

    Stefanos D. Georgiadis


    Full Text Available It is a challenge in evoked potential (EP analysis to incorporate prior physiological knowledge for estimation. In this paper, we address the problem of single-channel trial-to-trial EP characteristics estimation. Prior information about phase-locked properties of the EPs is assesed by means of estimated signal subspace and eigenvalue decomposition. Then for those situations that dynamic fluctuations from stimulus-to-stimulus could be expected, prior information can be exploited by means of state-space modeling and recursive Bayesian mean square estimation methods (Kalman filtering and smoothing. We demonstrate that a few dominant eigenvectors of the data correlation matrix are able to model trend-like changes of some component of the EPs, and that Kalman smoother algorithm is to be preferred in terms of better tracking capabilities and mean square error reduction. We also demonstrate the effect of strong artifacts, particularly eye blinks, on the quality of the signal subspace and EP estimates by means of independent component analysis applied as a prepossessing step on the multichannel measurements.

  20. ISCEV standard for clinical visual evoked potentials: (2016 update).

    Odom, J Vernon; Bach, Michael; Brigell, Mitchell; Holder, Graham E; McCulloch, Daphne L; Mizota, Atsushi; Tormene, Alma Patrizia


    Visual evoked potentials (VEPs) can provide important diagnostic information regarding the functional integrity of the visual system. This document updates the ISCEV standard for clinical VEP testing and supersedes the 2009 standard. The main changes in this revision are the acknowledgment that pattern stimuli can be produced using a variety of technologies with an emphasis on the need for manufacturers to ensure that there is no luminance change during pattern reversal or pattern onset/offset. The document is also edited to bring the VEP standard into closer harmony with other ISCEV standards. The ISCEV standard VEP is based on a subset of stimulus and recording conditions that provide core clinical information and can be performed by most clinical electrophysiology laboratories throughout the world. These are: (1) Pattern-reversal VEPs elicited by checkerboard stimuli with large 1 degree (°) and small 0.25° checks. (2) Pattern onset/offset VEPs elicited by checkerboard stimuli with large 1° and small 0.25° checks. (3) Flash VEPs elicited by a flash (brief luminance increment) which subtends a visual field of at least 20°. The ISCEV standard VEP protocols are defined for a single recording channel with a midline occipital active electrode. These protocols are intended for assessment of the eye and/or optic nerves anterior to the optic chiasm. Extended, multi-channel protocols are required to evaluate postchiasmal lesions. PMID:27443562

  1. Alterations in oropharyngeal sensory evoked potentials (PSEP) with Parkinson's disease.

    Pitts, Teresa; Hegland, Karen Wheeler; Sapienza, Christine M; Bolser, Donald C; Davenport, Paul W


    Movement of a food bolus from the oral cavity into the oropharynx activates pharyngeal sensory mechanoreceptors. Using electroencephalography, somatosensory cortical-evoked potentials resulting from oropharyngeal mechanical stimulation (PSEP) have been studied in young healthy individuals. However, limited information is known about changes in processing of oropharyngeal afferent signals with Parkinson's disease (PD). To determine if sensory changes occurred with a mechanical stimulus (air-puff) to the oropharynx, two stimuli (S1-first; S2-s) were delivered 500ms apart. Seven healthy older adults (HOA; 3 male and 4 female; 72.2±6.9 years of age), and thirteen persons diagnosed with idiopathic Parkinson's disease (PD; 11 male and 2 female; 67.2±8.9 years of age) participated. Results demonstrated PSEP P1, N1, and P2 component peaks were identified in all participants, and the N2 peak was present in 17/20 participants. Additionally, the PD participants had a decreased N2 latency and gated the P1, P2, and N2 responses (S2/S1 under 0.6). Compared to the HOAs, the PD participants had greater evidence of gating the P1 and N2 component peaks. These results suggest that persons with PD experience changes in sensory processing of mechanical stimulation of the pharynx to a greater degree than age-matched controls. In conclusion, the altered processing of sensory feedback from the pharynx may contribute to disordered swallow in patients with PD. PMID:27090350

  2. Source localisation of visual evoked potentials in congenitally deaf individuals.

    Hauthal, Nadine; Thorne, Jeremy D; Debener, Stefan; Sandmann, Pascale


    Previous studies have suggested that individuals deprived of auditory input can compensate with specific superior abilities in the remaining sensory modalities. To better understand the neural basis of deafness-induced changes, the present study used electroencephalography to examine visual functions and cross-modal reorganization of the auditory cortex in deaf individuals. Congenitally deaf participants and hearing controls were presented with reversing chequerboard stimuli that were systematically modulated in luminance ratio. The two groups of participants showed similar modulation of visual evoked potential (VEP) amplitudes (N85, P110) and latencies (P110) as a function of luminance ratio. Analysis of VEPs revealed faster neural processing in deaf participants compared with hearing controls at early stages of cortical visual processing (N85). Deaf participants also showed higher amplitudes (P110) than hearing participants. In contrast to our expectations, the results from VEP source analysis revealed no clear evidence for cross-modal reorganization in the auditory cortex of deaf participants. However, deaf participants tended to show higher activation in posterior parietal cortex (PPC). Moreover, modulation of PPC responses as a function of luminance was also stronger in deaf than in hearing participants. Taken together, these findings are an indication of more efficient neural processing of visual information in the deaf, which may relate to functional changes, in particular in multisensory parietal cortex, as a consequence of early auditory deprivation. PMID:24337445

  3. Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

    The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [3H]dopamine and [3H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [3H]dopamine and [3H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [3H]norepinephrine or [3H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

  4. Definition of compassion-evoking images in a Mexican sample.

    Mercadillo, Roberto E; Barrios, Fernando A; Díaz, José Luis


    To assemble a calibrated set of compassion-eliciting visual stimuli, 60 clinically healthy Mexican volunteers (36 women, 24 men; M age = 27.5 yr., SD = 2.4) assessed 84 pictures selected from the International Affective Picture System catalogue using the dimensions of Valence, Arousal, and Dominance included in the Self-assessment Manikin scale and an additional dimension of Compassion. Pictures showing suffering in social contexts and expressions of sadness elicited similar responses of compassion. The highest compassion response was reported for pictures showing illness and pain. Men and women differed in the intensity but not the quality of the compassionate responses. Compassion included attributes of negative emotions such as displeasure. The quality of the emotional response was not different from that previously reported for samples in the U.S.A., Spain, and Brazil. A set of 28 pictures was selected as high-compassion-evoking images and 28 as null-compassion controls suitable for studies designed to ascertain the neural substrates of this moral emotion. PMID:18065091

  5. Long-latency evoked potentials to irrelevant, deviant stimuli

    Snyder, E.; Hillyard, S. A.


    Occasional shifts of loudness in a repetitive train of clicks elicited a late-positive wave (P3a) in nonattending subjects which peaked at a mean latency of 258 msec and had a frontocentral scalp distribution; P3a was typically preceded by an 'N2' component at 196 msec. The P3a wave was distinguishable from the longer-latency (378 msec) parietocentrally distributed 'P3b' wave that was evoked by the same stimulus in an actively attending subject, thus confirming the findings of Squires et al. (1975). Infrequently presented single sounds did not produce large or consistent N2-P3a components; the critical condition for the generation of an N2-P3a wave seemed to be that the infrequent sounds represent a deviation (intensity increment or decrement) from a repetitive background. Furthermore, increasing the repetition rate of the background clicks drastically reduced N1-P2 amplitude but had little effect on the amplitude of N2-P3a. This suggests that N2-P3a is not simply a delayed N1-P2 'vertex potential', but rather reflects the operation of a 'mismatch' detector, which registers deviations from an ongoing auditory background.

  6. Flash visual evoked potentials in diurnal birds of prey.

    Dondi, Maurizio; Biaggi, Fabio; Di Ianni, Francesco; Dodi, Pier Luigi; Quintavalla, Fausto


    The objective of this pilot study was to evaluate the feasibility of Flash Visual Evoked Potentials (FVEPs) testing in birds of prey in a clinical setting and to describe the protocol and the baseline data for normal vision in this species. FVEP recordings were obtained from 6 normal adult birds of prey: n. 2 Harris's Hawks (Parabuteo unicinctus), n. 1 Lanner Falcon (Falco biarmicus), n. 2 Gyrfalcons (Falco rusticolus) and n. 1 Saker Falcon (Falco cherrug). Before carrying out VEP tests, all animals underwent neurologic and ophthalmic routine examination. Waveforms were analysed to identify reproducible peaks from random variation of baseline. At least three positive and negative peaks were highlighted in all tracks with elevated repeatability. Measurements consisted of the absolute and relative latencies of these peaks (P1, N1, P2, N2, P3, and N3) and their peak-to-peak amplitudes. Both the peak latency and wave morphology achieved from normal animals were similar to those obtained previously in other animal species. This test can be easily and safely performed in a clinical setting in birds of prey and could be useful for an objective assessment of visual function. PMID:27547536

  7. An evoked potential mapping of transcallosal projections in the cat

    A. Cukiert


    Full Text Available In ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions were determined on a cartesian map of most of the exposable neocortical areas and the potentials were analysed as to their components, voltage and latency. Passive spread and electrotonic potentials and the effects of increasing frequency were also analysed. The results showed large transcallosal potentials in some areas and an increase of potentials in the caudorostral direction, attaining the highest values in anteromedial areas of the suprasylvian gyrus. Confirming anatomical studies, a few silent spots were found in the motor and somesthetic cortex and in restricted posterior regions of the visual cortex, where small or zero voltages occurred. While causing weak contralateral potentials, stimulation of some posterior sites provoked high voltage potentials in anterior regions of the side being stimulated and in the corresponding area of the opposite site. These posterior sites are. poorly interconnected by the corpus callosum. The L-shaped indirect connection described in this work may be involved in some types of epilepsy and may explain the effectiveness of partial callosotomy in their treatment.

  8. Online Classification of Evoked EEG Signals Due to RGB Colors

    Eman Alharbi


    Full Text Available Recently, the impact of colors on the brain signals has become one of the leading researches in BCI systems. These researches are based on studying the brain behavior after color stimulus, and finding a way to classify its signals offline without considering the real time. Moving to the next step, we present a real time classification model (online for EEG signals evoked by RGB colors stimuli, which is not presented in previous studies. In this research, EEG signals were recorded from 7 subjects through BCI2000 toolbox. The Empirical Mode Decomposition (EMD technique was used at the signal analysis stage. Various feature extraction methods were investigated to find the best and reliable set, including Event-related spectral perturbations (ERSP, Target mean with Feast Fourier Transform (FFT, Wavelet Packet Decomposition (WPD, Auto Regressive model (AR and EMD residual. A new feature selection method was created based on the peak's time of EEG signal when red and blue colors stimuli are presented. The ERP image was used to find out the peak's time, which was around 300 ms for the red color and around 450 ms for the blue color. The classification was performed using the Support Vector Machine (SVM classifier, LIBSVM toolbox being used for that purpose. The EMD residual was found to be the most reliable method that gives the highest classification accuracy with an average of 88.5% and with an execution time of only 14 seconds.

  9. Brainstem auditory evoked potential testing in Dalmatian dogs in Brazil

    M.I.P. Palumbo


    Full Text Available The brain stem auditory-evoked potential (BAEP is an electrophysiologic test that detects and records the electrical activity in the auditory system from cochlea to midbrain, generated after an acoustic stimulus applied to the external ear. The aim of this study is to obtain normative data for BAEP in Dalmatian dogs in order to apply this to the evaluation of deafness and other neurologic disorders. BAEP were recorded from 30 Dalmatian dogs for a normative Brazilian study. Mean latencies for waves I, III, and V were 1.14 (±0.09, 2.62 (±0.10, and 3.46 (±0.14 ms, respectively. Mean inter-peak latencies for I-III, III-V, and I-V intervals were 1.48 (±0.17, 0.84 (±0.12, and 2.31 (±0.18 ms, respectively. Unilateral abnormalities were found in 16.7% of animals and bilateral deafness was seen in one dog. The normative data obtained in this paper is compatible with other published data. As far as we know this is the first report of deafness occurrence in Dalmatian dogs in Brazil.

  10. Intrinsic motivation and amotivation in first episode and prolonged psychosis.

    Luther, Lauren; Lysaker, Paul H; Firmin, Ruth L; Breier, Alan; Vohs, Jenifer L


    The deleterious functional implications of motivation deficits in psychosis have generated interest in examining dimensions of the construct. However, there remains a paucity of data regarding whether dimensions of motivation differ over the course of psychosis. Therefore, this study examined two motivation dimensions, trait-like intrinsic motivation, and the negative symptom of amotivation, and tested the impact of illness phase on the 1) levels of these dimensions and 2) relationship between these dimensions. Participants with first episode psychosis (FEP; n=40) and prolonged psychosis (n=66) completed clinician-rated measures of intrinsic motivation and amotivation. Analyses revealed that when controlling for group differences in gender and education, the FEP group had significantly more intrinsic motivation and lower amotivation than the prolonged psychosis group. Moreover, intrinsic motivation was negatively correlated with amotivation in both FEP and prolonged psychosis, but the magnitude of the relationship did not statistically differ between groups. These findings suggest that motivation deficits are more severe later in the course of psychosis and that low intrinsic motivation may be partially independent of amotivation in both first episode and prolonged psychosis. Clinically, these results highlight the importance of targeting motivation in early intervention services. PMID:26386901