- Email: [email protected]
En pratique, que doit-on savoir des syndromes neurologiques paranéoplasiques ?
86
Résumés/Abstracts
16
cortex, 4 in the amygdala, 3 in the prefrontal cortex, and 2 in the perigenual anterior cingulate. Mean difference in peak latencies was 15.3 ms, consistent with peripheral heat transduction time. The amplitude of local insular responses was not significantly different between laser and intra-epidermal stimulation (97.7 ± 45.0 and 77.6 ± 33.0 V, respectively; P = 0.24). However, when looking outside the insula, the magnitude of responses was significantly smaller for the IES-evoked potentials in the amygdala, perigenual cingulate and prefrontal/orbitofrontal cortices. We conclude that IES can effectively activate the A-delta system at non-nociceptive levels, and induce sizeable sensory insular responses; conversely, IES barely activates limbic, cingulate and prefrontal structures contributing to the cognitive and arousal value of the stimulus. Keywords A-delta; Intra-epidermal electrical stimulation; Laser
Evoked potential in multiple sclerosis: As important as 40 years ago but not for the same reasons Jean-Michel Guerit Edith Cavell Hospital, 32, rue Edith Cavell, 1180 Brussels, Belgium E-mail address: [email protected] Until the beginning of the 1980s, evoked potentials (EPs) were considered a unique diagnostic tool for multiple sclerosis (MS), particularly because of their capacity to reveal the presence of clinically hidden dysfunction in a sensory system when MS was suspected owing to clinically evident dysfunction in another brain or spinal cord area. Since the advent of magnetic resonance imaging (MRI), multiple lesions can be detected much more easily and reliably, which led some clinicians to consider that EPs had lost their place in the workup of MS patients. This holds not true as EPs remain of utmost importance in two indications: — as a method to objectivize ill-specific symptoms: provided that the stimulus should be adapted to the precise sensory sub-modality in which a deficit has been suspected, EPs may be used to decide whether or not the patient should be orientated toward MRI, less accessible and more expensive; — as a follow-up tool: based on some observations over time periods exceeding 30 years, we know that EPs remain remarkably stable in the absence of lesion appearance or evolution; therefore, we frequently use them to reliably reassure patients fearing relapses, based on non-specific symptoms. Consequently, we consider it both medically and economically justified getting a baseline recording of multimodality-evoked potentials in any patient in whom MS has been diagnosed. While the classical stimulus modalities (pattern visual, brainstem auditory, electrical somatosensory and motor EPs) should be preferred, other less-classical modalities (laser, vestibular myogenic, blink reflex) may prove useful in some specific cases. Keywords Evoked potentials; Follow-up; Multiple sclerosis Disclosure of interest peting interest.
The author declares that he has no com-
http://dx.doi.org/10.1016/j.neucli.2016.05.051 17
Comparison between intra-epidermal electrical and laser stimulation using direct intracranial recording of evoked potentials Koichi Hagiwara ∗ , Caroline Perchet , Maud Frot , Hélène Bastuji , Luis Garcia-Larrea Central Integration of Pain, Lyon Center for Neuroscience (INSERM U1028, CNRS UMR5292, Claude Bernard University), Lyon, France ∗ Corresponding author. Inserm U1028, intégration centrale de la douleur (NeuroPain), hôpital neurologique-Pierre-Wertheimer, 59, boulevard Pinel, 69677 Bron cedex, France. E-mail address: [email protected], [email protected] (K. Hagiwara) It has long been argued that the intra-epidermal electrical stimulation (IES) can stimulate A-delta fibres. The IES directly stimulates free nerve endings, therefore bypassing the temperature conduction delay of around 20 ms needed for laser-induced activation. However, there is no direct evidence to prove its selectivity to Adelta; this hampers its clinical application in comparison to the laser stimulation, which is currently the gold standard in this field. Here, we performed direct intracranial recordings in response to both IES (10 pulses at 49 Hz; 0.2—0.3 mA) and laser stimulation (Nd:YAP; 80—100 mJ/mm2 ). Seven (7) recording contacts were located in the posterior insula, 4 in the pericentral insula (posterior short gyrus 2, anterior long gyrus 1, central sulcus 1), 5 in the orbitofrontal
Disclosure of interest peting interest.
The authors declare that they have no com-
http://dx.doi.org/10.1016/j.neucli.2016.05.052 18
Pratique de la rTMS dans le traitement des syndromes douloureux chroniques : l’expérience grenobloise Hasan Hodaj ∗ , Jean-Pierre Alibeu , Caroline Maindet-Dominici , Anne Dumolard , Jean-Franc ¸ois Payen. Centre de la douleur, CHU Grenoble Alpes, CS 10217, 38043 Grenoble cedex 9, France ∗ Auteur correspondant. Adresse e-mail : [email protected] (H. Hodaj) Depuis 2007, notre équipe développe la rTMS dans les protocoles de recherche clinique et le traitement des douleurs chroniques réfractaires. Indications : algies faciales (AF), douleurs post-AVC, membre fantôme, avulsion du plexus brachial, glossodynie, névralgie pudendale. Notre protocole thérapeutique actuel utilise les paramètres de stimulation suivants : intensité à 80 % du seuil moteur, fréquence 10 Hz, trains 5 s, inter-trains 25 s, soit 2000 stimulations/20 min. Cible de stimulation : aire corticale motrice de la zone algique. Les séances sont guidées par un système de neuronavigation, sauf dans les névralgies pudendales (utilisation d’une sonde MagVenture B70 (Mag2Health, France), adaptée pour stimuler le cortex moteur bilatéral correspondant aux territoires pelvi-périnéaux). Nombre et rythme des séances : une « phase d’induction » : 1 séance/jour pendant 5 jours, 2 semaines consécutives (S1—S2), puis 2 séances (S3). Une « phase de maintien » chez les répondeurs (amélioration ≥ 30 %) : 1 séance (S4), puis 1 séance/15 jours pendant 5 mois. Si rémission incomplète : séances mensuelles pendant 6 mois. Si réponse faible ou récidive en cours du protocole : arrêt des séances de maintien. Avantages : maintien de l’effet antalgique à long terme. Inconvénients : séances fréquentes et temps médical incompressible. L’analyse de la littérature confirme l’efficacité de la rTMS dans les douleurs neuropathiques chroniques [3]. En général, les études sont de courte durée. Quelques études ont observé une meilleure réponse à la rTMS dans les AF, par rapport à d’autres sites douloureux [2]. Étude de notre centre [1] : 55 patients souffrant d’AF chroniques, effet antalgique ≥ 30 % obtenu chez 73 % des patients à j15 et 40 % à j180. L’effet antalgique est moindre après l’espacement mensuel des séances. Une diminution de la durée des séances de 20 à 10 min (nombre identique de stimulations) est moins efficace. Mots clés Algie faciale ; Douleur chronique réfractaire ; RTMS Déclaration de liens d’intérêts Les auteurs déclarent ne pas avoir de liens d’intérêts. Références [1] Hodaj H, Alibeu JP, Payen JF, Lefaucheur JP. Treatment of chronic facial pain including cluster headache by repetitive transcranial
Résumés/Abstracts
16
cortex, 4 in the amygdala, 3 in the prefrontal cortex, and 2 in the perigenual anterior cingulate. Mean difference in peak latencies was 15.3 ms, consistent with peripheral heat transduction time. The amplitude of local insular responses was not significantly different between laser and intra-epidermal stimulation (97.7 ± 45.0 and 77.6 ± 33.0 V, respectively; P = 0.24). However, when looking outside the insula, the magnitude of responses was significantly smaller for the IES-evoked potentials in the amygdala, perigenual cingulate and prefrontal/orbitofrontal cortices. We conclude that IES can effectively activate the A-delta system at non-nociceptive levels, and induce sizeable sensory insular responses; conversely, IES barely activates limbic, cingulate and prefrontal structures contributing to the cognitive and arousal value of the stimulus. Keywords A-delta; Intra-epidermal electrical stimulation; Laser
Evoked potential in multiple sclerosis: As important as 40 years ago but not for the same reasons Jean-Michel Guerit Edith Cavell Hospital, 32, rue Edith Cavell, 1180 Brussels, Belgium E-mail address: [email protected] Until the beginning of the 1980s, evoked potentials (EPs) were considered a unique diagnostic tool for multiple sclerosis (MS), particularly because of their capacity to reveal the presence of clinically hidden dysfunction in a sensory system when MS was suspected owing to clinically evident dysfunction in another brain or spinal cord area. Since the advent of magnetic resonance imaging (MRI), multiple lesions can be detected much more easily and reliably, which led some clinicians to consider that EPs had lost their place in the workup of MS patients. This holds not true as EPs remain of utmost importance in two indications: — as a method to objectivize ill-specific symptoms: provided that the stimulus should be adapted to the precise sensory sub-modality in which a deficit has been suspected, EPs may be used to decide whether or not the patient should be orientated toward MRI, less accessible and more expensive; — as a follow-up tool: based on some observations over time periods exceeding 30 years, we know that EPs remain remarkably stable in the absence of lesion appearance or evolution; therefore, we frequently use them to reliably reassure patients fearing relapses, based on non-specific symptoms. Consequently, we consider it both medically and economically justified getting a baseline recording of multimodality-evoked potentials in any patient in whom MS has been diagnosed. While the classical stimulus modalities (pattern visual, brainstem auditory, electrical somatosensory and motor EPs) should be preferred, other less-classical modalities (laser, vestibular myogenic, blink reflex) may prove useful in some specific cases. Keywords Evoked potentials; Follow-up; Multiple sclerosis Disclosure of interest peting interest.
The author declares that he has no com-
http://dx.doi.org/10.1016/j.neucli.2016.05.051 17
Comparison between intra-epidermal electrical and laser stimulation using direct intracranial recording of evoked potentials Koichi Hagiwara ∗ , Caroline Perchet , Maud Frot , Hélène Bastuji , Luis Garcia-Larrea Central Integration of Pain, Lyon Center for Neuroscience (INSERM U1028, CNRS UMR5292, Claude Bernard University), Lyon, France ∗ Corresponding author. Inserm U1028, intégration centrale de la douleur (NeuroPain), hôpital neurologique-Pierre-Wertheimer, 59, boulevard Pinel, 69677 Bron cedex, France. E-mail address: [email protected], [email protected] (K. Hagiwara) It has long been argued that the intra-epidermal electrical stimulation (IES) can stimulate A-delta fibres. The IES directly stimulates free nerve endings, therefore bypassing the temperature conduction delay of around 20 ms needed for laser-induced activation. However, there is no direct evidence to prove its selectivity to Adelta; this hampers its clinical application in comparison to the laser stimulation, which is currently the gold standard in this field. Here, we performed direct intracranial recordings in response to both IES (10 pulses at 49 Hz; 0.2—0.3 mA) and laser stimulation (Nd:YAP; 80—100 mJ/mm2 ). Seven (7) recording contacts were located in the posterior insula, 4 in the pericentral insula (posterior short gyrus 2, anterior long gyrus 1, central sulcus 1), 5 in the orbitofrontal
Disclosure of interest peting interest.
The authors declare that they have no com-
http://dx.doi.org/10.1016/j.neucli.2016.05.052 18
Pratique de la rTMS dans le traitement des syndromes douloureux chroniques : l’expérience grenobloise Hasan Hodaj ∗ , Jean-Pierre Alibeu , Caroline Maindet-Dominici , Anne Dumolard , Jean-Franc ¸ois Payen. Centre de la douleur, CHU Grenoble Alpes, CS 10217, 38043 Grenoble cedex 9, France ∗ Auteur correspondant. Adresse e-mail : [email protected] (H. Hodaj) Depuis 2007, notre équipe développe la rTMS dans les protocoles de recherche clinique et le traitement des douleurs chroniques réfractaires. Indications : algies faciales (AF), douleurs post-AVC, membre fantôme, avulsion du plexus brachial, glossodynie, névralgie pudendale. Notre protocole thérapeutique actuel utilise les paramètres de stimulation suivants : intensité à 80 % du seuil moteur, fréquence 10 Hz, trains 5 s, inter-trains 25 s, soit 2000 stimulations/20 min. Cible de stimulation : aire corticale motrice de la zone algique. Les séances sont guidées par un système de neuronavigation, sauf dans les névralgies pudendales (utilisation d’une sonde MagVenture B70 (Mag2Health, France), adaptée pour stimuler le cortex moteur bilatéral correspondant aux territoires pelvi-périnéaux). Nombre et rythme des séances : une « phase d’induction » : 1 séance/jour pendant 5 jours, 2 semaines consécutives (S1—S2), puis 2 séances (S3). Une « phase de maintien » chez les répondeurs (amélioration ≥ 30 %) : 1 séance (S4), puis 1 séance/15 jours pendant 5 mois. Si rémission incomplète : séances mensuelles pendant 6 mois. Si réponse faible ou récidive en cours du protocole : arrêt des séances de maintien. Avantages : maintien de l’effet antalgique à long terme. Inconvénients : séances fréquentes et temps médical incompressible. L’analyse de la littérature confirme l’efficacité de la rTMS dans les douleurs neuropathiques chroniques [3]. En général, les études sont de courte durée. Quelques études ont observé une meilleure réponse à la rTMS dans les AF, par rapport à d’autres sites douloureux [2]. Étude de notre centre [1] : 55 patients souffrant d’AF chroniques, effet antalgique ≥ 30 % obtenu chez 73 % des patients à j15 et 40 % à j180. L’effet antalgique est moindre après l’espacement mensuel des séances. Une diminution de la durée des séances de 20 à 10 min (nombre identique de stimulations) est moins efficace. Mots clés Algie faciale ; Douleur chronique réfractaire ; RTMS Déclaration de liens d’intérêts Les auteurs déclarent ne pas avoir de liens d’intérêts. Références [1] Hodaj H, Alibeu JP, Payen JF, Lefaucheur JP. Treatment of chronic facial pain including cluster headache by repetitive transcranial