Central pain with dissociated thermoalgesic sensory loss is common in spinal and brainstem syndromes but not cortical lesions. Out of a series 270 patients investigated because somatosensory abnormalities, we identified five subjects presenting central pure contralateral to stroke. All the had involvement posterior insula inner parietal operculum. Lemniscal modalities (position sense, graphaestesia, stereognosis) evoked potentials non-noxious inputs were always preserved, while thermal...

Conscious perception of painful stimuli needs the contribution an extensive cortico-subcortical network, and is completed in less than one second. While initial activities operculo-insular mid-cingulate cortices have been extensively assessed, activation timing most areas supporting conscious pain has barely studied. Here we used intracranial EEG to investigate dynamics 16 brain regions (insular, parietal, prefrontal, cingulate, hippocampal limbic) during first second following...

Thalamic pain is a severe and treatment-resistant type of central that may develop after thalamic stroke. Lesions within the ventrocaudal regions thalamus carry highest risk to pain, but its emergence in individual patients remains impossible predict. Because damage spino-thalamo-cortical system crucial factor development this study we combined detailed anatomical atlas-based mapping lesions assessment spinothalamic integrity using quantitative sensory analysis laser-evoked potentials 42...

Emotions modulate pain perception, although the mechanisms underlying this phenomenon remain unclear. In study, we show that intensity reports significantly increased when painful stimuli were concomitant to images showing human pain, whereas pictures with identical emotional values but without somatic content failed pain. Early somatosensory responses (<200 ms) remained unmodified by emotions. Conversely, late showed a significant enhancement associated ratings, localized right prefrontal,...

Pain can involuntarily capture attention and disrupt pain-unrelated cognitive activities. The brain mechanisms of these effects were explored by laser- visual-evoked potentials. Consecutive nociceptive laser stimuli visual delivered in pairs. Subjects instructed to ignore while performing a task on targets. Because involuntary is particularly sensitive novelty, some trials (17%), unexpected different hand area (location-deviant) relative the more frequent standard stimuli. Compared with...

Laser-evoked potentials (LEPs) are acknowledged as the most reliable laboratory tool for assessing thermal and pain pathways. Electrical stimulation with a newly developed planar concentric electrode, delivering stimuli limited to superficial skin layers, has been suggested provide selective activation of Aδ fibres without inconveniences linked laser stimulation. The aim our study was compare scalp intracranial responses electrode (CE-SEPs) those LEPs standard somatosensory-evoked (SEPs)....

Abstract Two parallel di-synaptic routes convey nociceptive input to the telencephalon: spino-thalamic system projecting principally posterior insula, and spino-parabrachial pathway reaching amygdalar nucleus. Interplay between two systems underlies sensory emotional aspects of pain, was explored here in humans with simultaneous recordings from amygdala, anterior insulae. Onsets thermo-nociceptive responses were virtually identical insula complex, but no significant functional connectivity...

We studied behavioural responses and 32-channel brain potentials to nociceptive stimuli during all-night sleep in 12 healthy subjects, using sequences of thermal laser pulses delivered over the dorsum hand. Laser less than 20 dB perception threshold had clear awakening properties, accordance with intrinsic threatening value signals. Even cases where stimulation did not interrupt sleep, it triggered motor 11% trials. Only four subjects reported dreams, on morning questionnaires there was no...

Abstract Observing other people's pain increases our own reports to painful stimuli, a phenomenon that can be defined as ‘compassional hyperalgesia’ ( CH ). This functional magnetic resonance imaging study examined the neural correlates of , and whether could emerge when exposure driving stimulus was subliminal. Subjects received electric somatosensory stimuli while observing images people undergoing or enjoyable somatic sensations, presented during period allowing not conscious perception....

The development of noninvasive techniques for the assessment functional brain maturation is critical. present study analyzed 63 babies' and children's (27 days to 5.5 years) cerebral responses a pattern-reversal visual stimulation using high-density (128 electrodes) electrophysiological recordings. Developmental data were further compared with those young adults (n = 16). Tremendous changes in pattern evoked potentials (pVEPs) morphology observed between 7 24 months characterized by...

While nociceptive cortical activation is now well characterized in humans, understanding of the thalamus remains largely fragmentary. We used laser stimuli and intracerebral electrodes 17 human subjects to record nociceptive-specific field responses 4 thalamic nuclei a number areas. Three known receive spinothalamic (STT) projections primates (ventro-postero-lateral [VPL], anterior pulvinar [PuA], central lateral [CL]) exhibited with similar latency, indicating their parallel by afferents....

To assess the processing stages involved in attention shifting and response selection tasks children, we recorded event-related potentials (ERPs) performance measures during a variant of Posner paradigm. Subjects responded to visual targets, either preceded by spatial cue (valid = same side; invalid opposite side) or presented uncued. Valid targets evoked high-amplitude P1 responses, single-peaked P3s, shortest reaction times (RTs). Invalidity cued stimuli delayed RTs, resulting part from...

Abstract Behavioral reactions to sensory stimuli during sleep are scarce despite preservation of sizeable cortical responses. To further understand such dissociation, we recorded intracortical field potentials painful laser pulses in humans waking and all‐night sleep. Recordings were obtained from the three structures receiving 95% spinothalamic input primates, namely parietal operculum, posterior insula, mid‐anterior cingulate cortex. The dynamics responses differed among sites. In Stage 2,...

It is acknowledged that the emotional state created by visual inputs can modulate way we feel pain; however, little known about how acute pain influences assessment of what see. In this study healthy subjects scored affective images while receiving painful or innocuous electrical shocks. Painful stimuli did not make unpleasant more unpleasant, but rendered pleasant pictures significantly less pleasant. Brain responses to (64-channels electroencephalogram) mirrored behavioural results,...

Key points Sleep spindle are usually considered to play a major role in inhibiting sensory inputs. Using nociceptive stimuli humans, we tested the effect of spindles on behavioural, autonomic and cortical responses two experiments using surface intracerebral electroencephalographic recordings. We found that sleep do not prevent arousal reactions reactivity inputs is modulated by activity. Moreover, neither sensory, nor insular evoked were spindle, as detected at or within thalamus. The...

<h2>Abstract</h2><h3>Objective</h3> Vestibular afferents converge with nociceptive ones within the posterior insula, and can therefore modulate nociception. Consistent this hypothesis, caloric vestibular stimulation (CVS) has been shown to reduce experimental clinical pain. Since CVS induce undesirable effects in a proportion of patients, here we explored an alternative means activate non-invasively pathways using innocuous bi-mastoid galvanic (GVS), assessed its on <h3>Methods</h3> Sixteen...

The use of mobile phones has been shown to increase drivers' reaction times (RTs), but whether this results from interference with attention, stimulus identification, or response production remains unclear. We recorded RTs and event-related brain potentials (ERPs) reflecting speed processing, attentional allocation, preparedness respond during a visual task performed without the concomitant phone, in either “hands-free” “phone-in-hand” operating modes. As expected, maintaining phone...

Innocuous cooling of the skin activates cold-specific Aδ fibres, and hence, recording cold-evoked potentials (CEPs) may improve objective assessment human thermo-nociceptive function. While feasibility CEP recordings in healthy humans has been reported, their reliability diagnostic use clinical conditions have not documented.Here, we report results 60 consecutive patients with suspected neuropathic pain, compared laser-evoked (LEPs) which are gold standard for thermo-algesic instrumental...

Abstract Intra‐epidermal electrical stimulation ( IEES ) has been shown to activate selectively Aδ fibers subserving spinothalamic‐mediated sensations. Owing electrically induced highly synchronous afferent volleys, induces Aδ‐mediated evoked potentials at nonpainful intensities, contrasting with thermo‐nociceptive laser pulses which entail painful pricking Here, we recorded intracortical responses from sensory and limbic‐cognitive regions of human subjects in response IEE stimuli, order...