Turning attention towards or away from a painful heat stimulus is known to modify both the subjective intensity of pain and cortical evoked potentials noxious stimuli. Using PET, we investigated in 12 volunteers whether pain-related regional cerebral blood flow (rCBF) changes were also modulated by attention. High (mean 46.6°C) low 39°C) thermal stimuli applied hand under three attentional conditions: (i) directed stimuli, (ii) diverted (iii) no task. Only insular/second somatosensory...

Although electrical stimulation of the precentral gyrus (MCS) is emerging as a promising technique for pain control, its mechanisms action remain obscure, and application largely empirical. Using positron emission tomography (PET) we studied regional changes in cerebral flood flow (rCBF) 10 patients undergoing motor cortex seven whom also underwent somatosensory evoked potentials nociceptive spinal reflex recordings. The most significant MCS-related increase rCBF concerned ventral-lateral...

Repetitive transcranial magnetic stimulation (rTMS) has been proposed to treat neuropathic pain but the quality of evidence remains low. We aimed assess efficacy and safety neuronavigated rTMS primary motor cortex (M1) or dorsolateral prefrontal (DLPFC) in over 25 weeks. carried out a randomized double-blind, placebo-controlled trial at four outpatient clinics France. Patients aged 18-75 years with peripheral were randomly assigned 1:1 ratio M1 DLPFC-rTMS rerandomized 2:1 active sham-rTMS...

What makes the painful cries of human babies so difficult to ignore? Vocal traits known as 'nonlinear phenomena’ are prime candidates. These acoustic irregularities common in babies’ and typically associated with high levels distress or pain. Despite vital importance for a baby’s survival, how these nonlinear phenomena drive pain perception adult listeners has not previously been systematically investigated. Here, by combining analyses recorded different contexts playback experiments using...

WE investigated the relation between subjective sensation of pain and two different components laser evoked potential, namely vertex response (N220-P350) an earlier lateralized (middle-latency NP160). Brain responses to stimuli were obtained in 15 subjects under attentive distractive conditions. Although stimulus intensity was kept constant, it perceived as significantly higher when attended stimulation. There a positive correlation perception amplitude but no existed with middle-latency...

<b>Background: </b> Motor cortex stimulation (MCS) for neuropathic pain control induces focal cerebral blood flow changes involving regions with high density of opioid receptors. We studied the possible contribution endogenous system to MCS-related relief. <b>Methods: Changes in receptor availability induced by MCS were PET scan and [¹¹C]diprenorphine eight patients refractory pain. Each patient underwent two preoperative (test–retest) scans one postoperative acquired after 7...

The clinical, electrophysiological and haemodynamic effects of precentral gyrus stimulation (PGS) as a treatment refractory post-stroke pain were studied in 2 patients. first patient had right hemibody secondary to left parietal infarct sparing the thalamus, while second lower limb developed after mesencephalic infarct. In both cases, spontaneous was associated with hyperpathia, allodynia hypoaesthesia painful territory involving lemniscal extra-lemniscal sensory modalities 1, modality only...

Thirty-one patients with medically refractory neuropathic pain were included in a prospective evaluation of motor cortex stimulation. The long-term outcome was evaluated using five variables: (a) rate (percentage) relief, (b) scores as assessed on VAS, (c) postoperative decrease VAS scores, (d) reduction analgesic drug intake, (e) dichotomic (yes/no) response to the question whether patient would accept, under similar circumstances, be operated again. Pain relief rated excellent (>70 %...

Thanks to the seminal work of Wilder Graves Penfield (1891-1976) at Montreal Neurological Institute, electrical stimulation is used worldwide localize epileptogenic cortex and map functionally eloquent areas in context epilepsy surgery or lesion resections. In functional elementary experiential responses he described through >20 years careful exploration human via cortical surface, did not identify any 'pain area'. We reinvestigated this issue by analysing subjective videotaped behavioural...

<b><i>Objective:</i></b> To investigate cerebral activity associated with allodynia in patients neuropathic pain. <b><i>Methods:</i></b> The brain responses of 27 peripheral (5), spinal (3), brainstem (4), thalamic lenticular or cortical (5) lesions were studied fMRI as innocuous mechanical stimuli addressed to either the allodynic territory homologous contralateral region. <b><i>Results:</i></b> When applied normal side, brush and cold rubbing did not evoke pain activated a somatosensory...

We used PET to study regional cerebral blood flow (rCBF) changes in nine patients with unilateral central pain after a lateral medullary infarct (Wallenberg's syndrome). All presented, on the abnormal side, combination of hypaesthesia noxious and thermal stimuli allodynia rubbing skin cold object (i.e. innocuous stimulation). The rCBF responses during were compared those obtained stimulation normal side using (i) non-noxious stimulus identical that applied painful (ii) an electrical...

The question whether pain encoding in the human insula shows some somatotopic organization is still pending. We studied 142 patients undergoing depth stereotactic EEG (SEEG) exploration of insular cortex for pre-surgical evaluation epilepsy. 472 electrical stimulations were delivered, which only 49 (10.5%) elicited a painful sensation 38 (27%). Most sites where low intensity electric stimulation produced pain, without after-discharge or concomitant visually detectable change activity outside...

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...

This study used positron emission tomography (PET) and [11C]diprenorphine to compare the in vivo distribution abnormalities of brain opioid receptors (OR) patients with peripheral (n=7) central post-stroke pain (CPSP, n=8), matched for intensity duration. Compared age- sex-matched controls, neuropathic (NP) showed bilateral symmetrical OR binding decrease, while CPSP decrease predominated hemisphere contralateral pain. In patients, interhemispheric comparison demonstrated a significant...

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...

In most human societies, grandparents often provide substantial care and support for their grandchildren, including as babies. Given that previous studies have shown ageing is accompanied by a gradual decline in our ability to identify other people’s emotions, does age also reduce skill at understanding baby’s cries? Here, we show older people with experience of caring babies remain able correctly decode the information conveyed babies’ cries. The results psychoacoustic experiments underline...

Parietal, insular and anterior cingulate cortices are involved in the processing of noxious inputs genesis pain sensation. Parietal lesions may generate central by mechanisms generally assumed to involve ‘medial’ system (i.e. medial thalamic nuclei cortex (ACC)). We report here PET fMRI data a patient who developed allodynia her left side after bifocal infarct involving both right parietal (SI SII) ACC (Brodmann areas 24 32), thus questioning schematic representation cortical processing. No...