Project

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Intraoperative neuromodulation and neuromonitoring of the temporal lobe

Applicant Boex Colette
Number 149804
Funding scheme Project funding (Div. I-III)
Research institution Unité d'EEG et d'exploration de l'épilepsie Service de Neurologie Hôpitaux Universitaires de Genève
Institution of higher education University of Geneva - GE
Main discipline Neurology, Psychiatry
Start/End 01.10.2013 - 30.09.2016
Approved amount 337'000.00
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All Disciplines (3)

Discipline
Neurology, Psychiatry
Neurophysiology and Brain Research
Surgery

Keywords (3)

neurophysiology; olfaction; epilepsy

Lay Summary (French)

Lead
Ce projet de recherche est dédié à l'exploration du lobe temporal chez l’être humain. Au-delà de l'exploration des voies visuelles et du langage pour lesquelles nous participons à d'autres projets, le présent projet se concentre sur l'exploration de l'olfaction (neuromonitoring intraopératoire et étude du cortex primaire), de la mémoire (stimulation entorhinale), de la chirurgie du lobe temporal pour l'épilepsie (hippocampe, cortex entorhinal, gyrus T1) et sa neuromodulation.
Lay summary

La surveillance des fonctions olfactives sera développée comme une nouvelle modalité du neuromonitoring, destinée à éviter des déficits sensoriels iatrogènes en neurochirurgie. Le projet pourra également permettre de mieux comprendre le cortex olfactif primaire de l'être humain. L'étude sera proposée aux patients qui doivent subir une intervention neurochirurgicale en raison d'une lésion temporale ou frontale. L'exploration des voies olfactives, du cortex olfactif primaire peut être réalisée pendant ces interventions et en particulier avec l'exposition de cortex entorhinal. Ces mesures comporteront également des enregistrements de microélectrodes.

Pour certains patients atteints d'épilepsie du lobe temporal, la chirurgie peut être un traitement efficace, mais peut présenter des risques neuropsychologiques. Nous proposons de continuer à examiner les effets intra-opératoires de chaque étape de la chirurgie pour mieux comprendre les réseaux épileptiques temporaux. Dans la lignée des études menées sur ces pathologies et des analyses des résultats de la chirurgie, le neuromonitoring intraopéropératoire de l'activité épileptique questionne le rôle de l'hippocampe dans l'épilepsie du lobe temporal. Le cortex temporal supérieur et le cortex entorhinal, apparaissent eux aussi comme deux sites importants. Nous faisons l'hypothèse que ces sites pourraient apparaître comme de nouvelles cibles pour la stimulation cérébrale dans l'épilepsie.
La stimulation du cortex entorhinal sera aussi évaluée sur sa capacité à améliorer la mémoire. Cela pourrait ouvrir de nouvelles perspectives dans les traitements palliatifs de la maladie d'Alzheimer ou de démence avec sclérose hippocampique, afin d'améliorer la qualité de vie de ces patients.

Direct link to Lay Summary Last update: 16.10.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
What Is the Best Electrophysiologic Marker of the Outcome of Subthalamic Nucleus Stimulation in Parkinson Disease?
Boëx Colette, Tyrand Rémi, Horvath Judit, Fleury Vanessa, Sadri Sarvenaz, Corniola Marco, Burkhard Pierre R., Momjian Shahan (2018), What Is the Best Electrophysiologic Marker of the Outcome of Subthalamic Nucleus Stimulation in Parkinson Disease?, in World Neurosurgery, 120, e1217-e1224.
Low frequency microstimulation is locally excitatory in patients with epilepsy
Bartoli Andrea, TyrandRémi, VargasMaria Isabel, MomjianShahan, BoexColette (2018), Low frequency microstimulation is locally excitatory in patients with epilepsy, in Clinical Neurophysiology, 12(12), 22.
Continuous Intraoperative Monitoring of Temporal Lobe Epilepsy Surgery
Tyrand Rémi, Momjian Shahan, Pollo Claudio, Lysakowski Christopher, Lascano Agustina M., Vulliémoz Serge, Schaller Karl, Boëx Colette (2017), Continuous Intraoperative Monitoring of Temporal Lobe Epilepsy Surgery, in Stereotactic and Functional Neurosurgery, 94(6), 404-412.
Amygdalo-hippocampal deep brain stimulation for mesial temporal lobe epilepsy
Bartoli A (2014), Amygdalo-hippocampal deep brain stimulation for mesial temporal lobe epilepsy, in Clinical Neurophysiology, 125(S1), S152.

Collaboration

Group / person Country
Types of collaboration
Unité de Rhinologie Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Laboratoire Lüscher Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Neurosurgery HUG Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
Neuro-Anesthesia Unit Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Laboratoire de neuropsychologie expérimentale Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
XXII Congress of the European Society for Stereotatic and Functional Neurosurgery Talk given at a conference Intraoperative neurophysiological markers of the success of STN-DBS: microelectrode recordings, stimulation, beta oscillations ? 28.09.2016 Madrid, Spain Boex Colette;
3rd SFCNS Congress Swiss Federation of Clinical Neuro-Societies Talk given at a conference Low frequency microstimulation in patients with epilepsy does not produce inhibition but stimulator can 28.09.2016 Bâle, Switzerland Boex Colette; Momjian Shahan; Tyrand Rémi;
OptoDBS 2015 Poster Intraoperative neurophysiological markers of the success of STN-DBS: microelectrode recordings, stimulation, beta oscillations ? 07.05.2015 Genève, Switzerland Tyrand Rémi; Boex Colette; Momjian Shahan;


Knowledge transfer events

Active participation

Title Type of contribution Date Place Persons involved
EPHJ . EPMT . SMT Talk 09.06.2015 Genève, Switzerland Boex Colette;


Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions Stimulation cérébrale profonde Western Switzerland 2015

Associated projects

Number Title Start Funding scheme
133080 Integration of advanced biomarkers to deep brain stimulation in epilepsy 01.10.2010 Project funding (Div. I-III)

Abstract

This research project is dedicated to the exploration of the temporal lobe in humans. Beyond the exploration of visual pathways and of language processing for which we participate to other research projects, the present project focused on the exploration of olfaction, memory, epilepsy surgery and neuromodulation of temporal lobe. The intraoperative monitoring of olfaction, will be developped as a new modality in neuromonitoring, to prevent iatrogenic sensory deficits in neurosurgery. The project could also afford to better understanding of primary olfactory cortex in human. The study will be proposed to patients who have to undergo neurosurgical procedure because of temporal or frontal lesion. The exploration of olfactory pathways, of the primary olfactory cortex can be performed intraoperatively and in particular with the exposure of entorhinal cortex. General anaesthesia will be performed under electroencephalogram control (BIS spectral analysis) to ensure appropriate level of cerebral activity with adequate depth of anesthesia. The olfactory stimulation will be performed with chemicals (H2S, CO2). Recordings will be performed with updated methods (e.g. subdermal needles, shielded cables, microelectrode recordings). Signal analyses will include spectral analyses. For some patients with temporal lobe epilepsy, the surgery is still an efficient treatment, but with some neuropsychological risks. We propose to continue to scrutinize intraoperatively the effects of each step of temporal lobe surgery on epileptogenicity. Improvements in understanding of epileptic networks will be achieved by scrutinizing intra-operatively the effects of surgery on epileptogenicity. In the line with pathological studies and surgery outcome analyses, intraoperative neuromonitoring of the epileptiform activity during temporal lobe surgery re-enforces the possibility that the hippocampus is secondary implied in temporal lobe epilepsy. Conversely, superior temporal cortex as well as entorhinal cortex, appear as two important sites. We make the hypotheses that: superior temporal cortex (T1) or entorhinal cortex could appear as new targets for brain stimulation in epilepsy. Randomized entorhinal or superior-temporal gyrus electrical stimulation will contribute to guide future evaluation of chronic stimulation. Effects of stimulation (charge balanced biphasic pulses, for 50 and 130 Hz, monopolar) will be measured with interictal epileptiform discharge rates, with evoked potentials and microelectrode recordings. The entorhinal cortex will be evaluated for memory enhancement. The changes in implicit and explicit memory will be evaluated with neuropsychological tests (hits with priming for implicit memory, delayed recall for explicit memory). This study will afford to evaluate entorhinal stimulation as a target for memory enhancement. This could open new insights in palliative treatments of Alzheimer’s disease or of hippocampal sclerosis with dementia, improving the quality of life of patients.
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