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Transcranial brain stimulation: Moving ahead with the brakes firmly on?
Neurophysiologie Clinique/Clinical Neurophysiology (2011) 42, 59—71
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BURGUNDY MEETING 2012 — BEAUNE (FRANCE), JANUARY 25—28, 2012
Abstracts
Session: TMS 1
Transcranial brain stimulation: Moving ahead with the brakes firmly on? J. Rothwell UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom Adresse e-mail : [email protected] Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS) are the most important methodological advances in clinical neurophysiology since the advent of EEG. Like EEG, TMS and TDCS give us information about the activities, connectivity and behavioural consequences of interconnected populations of neurones. Indeed, combining these methods with other methods of imaging evoked activity in the brain, such as EEG, NIRS and fMRI, increases their potential far beyond the motor cortex where much of the initial work was done. Unlike imaging methods however, both TMS and TDCS are capable not only of probing brain activity but also of influencing patterns of activity for many minutes or hours after stimulation, through their effects on LTP- and LTD-like plasticity. This finding has led to a huge interest in the potential therapeutic applications of these methods, particularly in rehabilitation medicine. New methods are also becoming available, from modifications of TMS and TDCS such as depotentiation protocols to investigate brain plasticity or random noise/alternating current TDCS to methods such as static magnetic field stimulation and focussed low frequency ultrasound. I will discuss some of these new approaches, and highlight their advantages and potential uses. However, like all transcranial stimulation methods they suffer from one major problem: interindividual variability in response. This means, for example, that despite the success of TMS/TDCS in probing pathophysiology their use in diagnosis has proved to be much less successful. The very large individual variation in the effects of stimulation means that although there may be clear population differences between responses evoked in one group of patients and another, the overlap of data from individuals in the two groups is very high. It is not surprising then to find that corticospinal conduction velocity, which has a small inter-individual variance in healthy volunteers, is one of the most highly used diagnostic measures in
0987-7053/$ – see front matter
myelopathy, amyotrophic lateral sclerosis and multiple sclerosis. A task for the future must be to try to reduce this variance and bring brain stimulation methods more firmly into the clinical arena. I will describe some new data describing a number of factors that can be highly predictive of the response to TMS, potentially opening up the possibility of selecting healthy individuals or people with neurological disease who will best respond to particular protocols or therapeutic manipulations. doi:10.1016/j.neucli.2011.11.022 2
Multifocal physiologically balanced neuromodulation for treatment of neurological conditions S. Filipoviˇ c a,b , J. Milan a , J. Aleksandra b , M. Slaðan a , D. Aleksandra b,c , K. Ljubica b,c a Department for Neurophysiology, Institute for Medical Reseach, University of Belgrade, Ul. Dr Subotiˇca 4, 11000 Beograd, Serbia b Hospital for Rehabilitation, Dr Miroslav Zotoviˇ c, Ul. Sokobanjska, 11000 Beograd, Serbia c Department of Rehabilitation and Physical Medicine, Faculty of Medicine, University of Belgrade, 11000 Beograd, Ul. Dr Subotiˇca 6, Beograd, Serbia Adresse e-mail : sasa.fi[email protected] (S. Filipoviˇ c) Typically, brain activity is realized through functional networks linking number of disparate regions around a certain task. The networks differ according to the actions that are performed. Interconnected regions mutually regulate and maintain their levels of activation and excitability keeping certain pre-established homeostatic equilibrium. In neurological and psychiatric disorders, regardless of the site of the actual morphological lesion or original functional deficiency, the whole networks or their larger parts are eventually affected, shifting the network equilibrium to new homeostatic levels. This may be the reason for relatively feeble clinical effects obtained so far by noninvasive neuromodulation methods, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS). Almost all clinically oriented studies targeted a single cortical area, trying to modulate its activation and excitability. However, regardless of possible acute beneficial effects, the long-term changes have been usually largely obliterated, most likely through metaplastic homeostatic influences
Disponible en ligne sur
www.sciencedirect.com
BURGUNDY MEETING 2012 — BEAUNE (FRANCE), JANUARY 25—28, 2012
Abstracts
Session: TMS 1
Transcranial brain stimulation: Moving ahead with the brakes firmly on? J. Rothwell UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom Adresse e-mail : [email protected] Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS) are the most important methodological advances in clinical neurophysiology since the advent of EEG. Like EEG, TMS and TDCS give us information about the activities, connectivity and behavioural consequences of interconnected populations of neurones. Indeed, combining these methods with other methods of imaging evoked activity in the brain, such as EEG, NIRS and fMRI, increases their potential far beyond the motor cortex where much of the initial work was done. Unlike imaging methods however, both TMS and TDCS are capable not only of probing brain activity but also of influencing patterns of activity for many minutes or hours after stimulation, through their effects on LTP- and LTD-like plasticity. This finding has led to a huge interest in the potential therapeutic applications of these methods, particularly in rehabilitation medicine. New methods are also becoming available, from modifications of TMS and TDCS such as depotentiation protocols to investigate brain plasticity or random noise/alternating current TDCS to methods such as static magnetic field stimulation and focussed low frequency ultrasound. I will discuss some of these new approaches, and highlight their advantages and potential uses. However, like all transcranial stimulation methods they suffer from one major problem: interindividual variability in response. This means, for example, that despite the success of TMS/TDCS in probing pathophysiology their use in diagnosis has proved to be much less successful. The very large individual variation in the effects of stimulation means that although there may be clear population differences between responses evoked in one group of patients and another, the overlap of data from individuals in the two groups is very high. It is not surprising then to find that corticospinal conduction velocity, which has a small inter-individual variance in healthy volunteers, is one of the most highly used diagnostic measures in
0987-7053/$ – see front matter
myelopathy, amyotrophic lateral sclerosis and multiple sclerosis. A task for the future must be to try to reduce this variance and bring brain stimulation methods more firmly into the clinical arena. I will describe some new data describing a number of factors that can be highly predictive of the response to TMS, potentially opening up the possibility of selecting healthy individuals or people with neurological disease who will best respond to particular protocols or therapeutic manipulations. doi:10.1016/j.neucli.2011.11.022 2
Multifocal physiologically balanced neuromodulation for treatment of neurological conditions S. Filipoviˇ c a,b , J. Milan a , J. Aleksandra b , M. Slaðan a , D. Aleksandra b,c , K. Ljubica b,c a Department for Neurophysiology, Institute for Medical Reseach, University of Belgrade, Ul. Dr Subotiˇca 4, 11000 Beograd, Serbia b Hospital for Rehabilitation, Dr Miroslav Zotoviˇ c, Ul. Sokobanjska, 11000 Beograd, Serbia c Department of Rehabilitation and Physical Medicine, Faculty of Medicine, University of Belgrade, 11000 Beograd, Ul. Dr Subotiˇca 6, Beograd, Serbia Adresse e-mail : sasa.fi[email protected] (S. Filipoviˇ c) Typically, brain activity is realized through functional networks linking number of disparate regions around a certain task. The networks differ according to the actions that are performed. Interconnected regions mutually regulate and maintain their levels of activation and excitability keeping certain pre-established homeostatic equilibrium. In neurological and psychiatric disorders, regardless of the site of the actual morphological lesion or original functional deficiency, the whole networks or their larger parts are eventually affected, shifting the network equilibrium to new homeostatic levels. This may be the reason for relatively feeble clinical effects obtained so far by noninvasive neuromodulation methods, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (TDCS). Almost all clinically oriented studies targeted a single cortical area, trying to modulate its activation and excitability. However, regardless of possible acute beneficial effects, the long-term changes have been usually largely obliterated, most likely through metaplastic homeostatic influences