Neuroanatomy and lesion networks of central poststroke pain.

Identifying lesion sites associated with central poststroke pain (CPSP) may facilitate targeted screening for early symptoms, possibly even paving the way for preventive measures and earlier treatment initiation. Here, we test the hypothesis that damage to a nociceptive pathway extending from the brainstem to the cerebral cortex, and including white matter tracts, is associated with CPSP. We investigated the lesion locations of 72 patients with CPSP relative to poststroke comparison subjects without pain (n = 123), divided into a discovery and independent validation data set.

Cardiac autonomic responses to cortical electrical stimulation: a SEEG study.

Recent growing neuroimaging evidence support that a set of cortical regions - the central autonomic network - is involved in autonomic control, but its functional organization remains unclear. We studied the direct autonomic cardiac effects produced by 1500 direct cortical electrical stimulations in 43 patients with epilepsy (32.8 ± 8.

Investigating brain dysfunction in neuropathic pain with MRI.

Neuropathic pain is a severe chronic disease following nervous system lesions. Allodynia is a main symptom of neuropathic pain, and it can be easily triggered by normally innocuous stimuli inside a functional MRI magnet. In this new series of 35 patients (age ranges: 33-82 years old, 14 females, 21 males, peripheral neuropathic pain: 4, central neuropathic pain: 31), we investigated mechanical dynamic and thermal cold allodynia.

Dissecting neuropathic from poststroke pain: the white matter within.

Poststroke pain (PSP) is a heterogeneous term encompassing both central neuropathic (ie, central poststroke pain [CPSP]) and nonneuropathic poststroke pain (CNNP) syndromes. Central poststroke pain is classically related to damage in the lateral brainstem, posterior thalamus, and parietoinsular areas, whereas the role of white matter connecting these structures is frequently ignored. In addition, the relationship between stroke topography and CNNP is not completely understood.

The Modular Organization of Pain Brain Networks: An fMRI Graph Analysis Informed by Intracranial EEG.

Intracranial EEG (iEEG) studies have suggested that the conscious perception of pain builds up from successive contributions of brain networks in less than 1 s. However, the functional organization of cortico-subcortical connections at the multisecond time scale, and its accordance with iEEG models, remains unknown. Here, we used graph theory with modular analysis of fMRI data from 60 healthy participants experiencing noxious heat stimuli, of whom 36 also received audio stimulation.

Contextual modulation of autonomic pain reactivity.

Although modulation of cardiac activity may be influenced by several factors, interaction between autonomic nociceptive responses and the high-level of cortical processes is not clearly understood. Here, we studied in 26 subjects whether empathetic or unempathetic contexts could interact with autonomic pain responses. RR intervals variability was used to approach parasympathetic and sympathetic responses to painful thermal stimulations, according to contexts evoked by experimenters' comments.

Retrieving autobiographical experience of painful events in a phantom limb: brain concomitants in a case report.

We report the case of a patient who had an important experience with painful events, allowing the investigation of brain concomitants to painful (P) memories in fMRI. The patient had to recall P events that were contrasted with non-painful (NP) memories. Painful memories of the right lower limb activated the left paracentral lobule,fronto-insular operculum and superior parietal cortex.

Easy methods to make the neuronavigated targeting of DLPFC accurate and routinely accessible for rTMS.

Objectives: Dorsolateral prefrontal cortex (DLPFC) is the main stimulation target for rTMS treatment of depression. DLPFC is located in the middle frontal gyrus and corresponds to the lateral part of Brodmann Areas 9 and 46. Current methods to locate the DLPFC are either based on head landmarks that are inaccurate, or based on MRI-neuronavigation.

Macroanatomy and 3D probabilistic atlas of the human insula.

The human insula is implicated in numerous functions. More and more neuroimaging studies focus on this region, however no atlas offers a complete subdivision of the insula in a reference space. The aims of this study were to define a protocol to subdivide insula, to create probability maps in the MNI152 stereotaxic space, and to provide normative reference volume measurements for these subdivisions.

Processing of nociceptive input from posterior to anterior insula in humans.

Previous brain imaging studies have shown robust activations in the insula during nociceptive stimulation. Most activations involve the posterior insular cortex but they can cover all insular gyri in some fMRI studies. However, little is known about the timing of activations across the different insular sub-regions.

The 'where' and the 'when' of the BOLD response to pain in the insular cortex. Discussion on amplitudes and latencies.

The operculo-insular cortex has been recently pointed out to be the main area of the pain matrix to be involved in the integration of pain intensity. This fMRI study specified the pattern of response to laser stimuli by focusing on this cortical area, by optimizing the temporal sampling and by investigating pain-related differences in the amplitudes and latencies of the BOLD responses. Canonical and temporal derivative hemodynamic response function (HRF) and finite impulse response (FIR) modeling provided consistent results.

Brain plasticity in the motor network is correlated with disease progression in amyotrophic lateral sclerosis.

Objective: To test the influence of functional cerebral reorganization in amyotrophic lateral sclerosis (ALS) on disease progression.

Methods: Nineteen predominantly right-handed ALS patients and 21 controls underwent clinical evaluation, functional Magnetic Resonance Imaging (fMRI), and diffusion tensor imaging. Patients were clinically re-evaluated 1 year later and followed until death.

Influence of emotional content and context on memory in mild Alzheimer's disease.

Healthy subjects remember emotional stimuli better than neutral, as well as stimuli embedded in an emotional context. This better memory of emotional messages is linked to an amygdalo-hippocampal cooperation taking place in a larger fronto-temporal network particularly sensitive to pathological aging. Amygdala is mainly involved in gist memory of emotional messages.

Spatial segregation of somato-sensory and pain activations in the human operculo-insular cortex.

The role of operculo-insular region in the processing of somato-sensory inputs, painful or not, is now well established. However, available maps from previous literature show a substantial overlap of cortical areas activated by these stimuli, and the region referred to as the "secondary somatosensory area (SII)" is widely distributed in the parietal operculum. Differentiating SII from posterior insula cortex, which is anatomically contiguous, is not easy, explaining why the "operculo-insular" label has been introduced to describe activations by somatosensory stimuli in this cortical region.

[Functional brain mapping of pain perception].

In this review, we summarize the contribution of functional imaging to the question of nociception in humans. In the beginning of the 90's, brain areas supposed to be involved in physiological pain processes were almost exclusively the primary somatosensory area (SI), thalamus, and anterior cingulate cortex. In spite of these a priori hypotheses, the first imaging studies revealed that the main brain areas and those providing the most consistent activations in pain conditions were the insular and the SII cortices, bilaterally.

How a clock can change your pain? The illusion of duration and pain perception.

The intensity of experimental pain is known to be dependent on stimulation duration. However, it remains unknown whether this effect arises largely from the actual stimulus duration or is substantially influenced by the subject's perception of the stimulus duration. In the present study, we questioned this issue by misleading the perception of the duration of pain in a population of 36 healthy volunteers stimulated with a thermode.

De novo artistic activity following insular-SII ischemia.

We report here the case of a female patient who developed the following behavioural changes after a brain lesion involving the left posterior insula and SII cortices. She discovered de novo artistic capabilities for painting, with an episodic and compulsive need to paint ("hyperpainting"), but also exhibited changes in her ability to feel emotions. In addition, she had a typical neuropathic pain syndrome, including provoked pain and spontaneous pain, whose intensity was worsened when she painted with cold colours.

Lack of specific gray matter alterations in restless legs syndrome in elderly subjects.

Magnetic resonance imaging studies using voxel-based morphometry (VBM) have been inconsistent in demonstrating volumetric differences in patients with restless legs syndrome (RLS). Since treatment, age and selection of patients may introduce a methodological bias, we conducted optimized VBM analyses in unmedicated elderly subjects reporting RLS. Two hundred-four voluntaries, 65.

Can we share a pain we never felt? Neural correlates of empathy in patients with congenital insensitivity to pain.

Theories of empathy differ regarding the relative contributions of automatic resonance and perspective taking in understanding others' emotions. Patients with the rare syndrome of congenital insensitivity to pain cannot rely on "mirror matching" (i.e.

Undiagnosed sleep-related breathing disorders are associated with focal brainstem atrophy in the elderly.

Background: Sleep-related breathing disorders (SRBDs) affect as many as 40% of elderly people. The association of SRBDs with structural brain abnormalities remains unclear. In this observational study, we evaluated gray matter changes in the brain associated with sleep abnormalities in volunteers and their relationship with the severity of SRBDs.

Motor cortex stimulation in neuropathic pain. Correlations between analgesic effect and hemodynamic changes in the brain. A PET study.

To investigate brain mechanisms whereby electrical stimulation of the motor cortex (MCS) may induce pain relief in patients with neuropathic pain, cerebral blood flow (CBF) changes were studied using H2O PET in 19 consecutive patients treated with MCS for refractory neuropathic pain. Patients were studied in three conditions, (a) before MCS (Baseline, stimulator stopped 4 weeks before), (b) during a 35-min period of MCS and (c) during a 75-min period after MCS had been discontinued (OFF). Compared to Baseline, turning on the stimulator was associated with CBF increase in the contralateral (anterior) midcingulate cortex (aMCC, BA24 and 32) and in the dorso-lateral prefrontal (BA10) cortices.

A 18F-MPPF PET normative database of 5-HT1A receptor binding in men and women over aging.

Unlabelled: Neurotransmission imaging studies require normative data for the statistical assessment of neurophysiologic dysfunctions. 2'-Methoxyphenyl-(N-2'-pyridinyl)-p-18F-fluoro-benzamidoethylpiperazine (18F-MPPF) is a specific serotonin 5-HT1A antagonist PET tracer recently characterized, modeled, and used for clinical research to explore abnormalities in the serotoninergic system. Our study reports, to our knowledge, the first large normative imaging database of 18F-MPPF binding potential (BP) over aging, for both males and females.

Statistical parametric mapping of 5-HT1A receptor binding in temporal lobe epilepsy with hippocampal ictal onset on intracranial EEG.

Experimental data in animals show that 5-HT(1A) receptors are predominantly located in limbic areas and suggest that serotonin, via these receptors, mediates an antiepileptic and anticonvulsant effect. In this PET study, we used an antagonist of the 5-HT(1A) receptor, [(18)F]MPPF, to assess the extent of 5-HT(1A) receptor binding changes in a group of seven temporal lobe epilepsy (TLE) patients with hippocampal ictal onset demonstrated by intracerebral EEG recording. On the basis of MRI-measured hippocampal volumes (HV), patients were classified into "normal HV" or "hippocampal atrophy" (HA).