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Scientific background to epilepsy therapy

Dr Nagai’s research started with investigations into how brain and peripheral body reactions are related each other. We think that when our brain gets excited, our body does too, but it is not always the case.

Dr Nagai measures and observes a body signal called electrodermal activity (EDA)/Galvanic Skin Response (GSR) which is very sensitive to our thoughts and emotions. You may know already that EDA is used in lie detector tests. Dr Nagai’s research has extensively investigated how changes in EDA also modulate different brain signals. To this end Dr Nagai has applied tools including electroencephalography (EEG) and functional MRI (fMRI). Dr Nagai is currently investigating further neural mechanisms through which ACRT helps seizure control.

The results from the clinical trial.

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adapted from Nagai et al. Epilepsy and Behaviour 2004, Vol 5/2: 216-223.

(adapted from Nagai et al. Psychosomatic Medicine 2009, 71: 84-92.)Click on the image to enlarge
adapted from Nagai et al. Psychosomatic Medicine 2009, 71: 84-92.

These participants all had drug resistant epilepsy, and had been on different types of medication
for many years (for some of them, over 20years).


The effect of the therapy over three years

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adapted from Nagai et al. Epilepsy Research 2014, 108: 149-52

science4Click on the image to enlarge
adapted from Nagai et al. Epilepsy Research 2014, 108: 149-52.

Once a participant learns the skill of controlling seizures through the training sessions,
the effect can last for many years.


The functional activity of distinct brain regions changes

science5Click on the image to enlarge
adapted from Nagai et al. Neuroimage 2004, 22:243-251

The functional activity of distinct brain regions changes during biofeedback. Our new research shows that one month of ACRT training increases resilience of people to anxiety-related seizure attacks.

About Dr Yoko Nagai

Dr Yoko Nagai began her research in electrodermal biofeedback therapy for epilepsy in 1997. This research has since attracted scientific research funding of over £300,000 that has enabled clinical trials and a deeper understanding of the brain mechanisms by which the therapy can reduce the occurrence of epileptic seizures. Dr Nagai also founded the Biofeedback Clinic in 2005, in response to demand from patients at the National Hospital for Neurology and Neurosurgery, University College London. Dr Nagai is currently a research fellow at Brighton and Sussex Medical School.


Selected Publications

Nagai Y. Modulation of autonomic activity in neurological conditions: epilepsy and Tourette Syndrome. Frontiers Autonomic Neuroscience. 2015, volume9, article 278  

Critchety HD, Nicotra A, Chiesa PA, Nagai Y, Gray MA, Minati L, Bernardi L. Slow breathing and hypoxic challenge: cardiorespiratory consenquences and their central neural substrates. PLoS One 2015, May 14 10(5): e0127082.

Hawksley J, Cavanna AE, Nagai Y The role of the autonomic nervous system in Tourette Syndrome. Frontiers Autonomic Neuroscience. 2015, volume 9: article 117

Critchley HD and Nagai Y What does left-right autonomic asymmetry signify? (commentary). Emotion Review. ISSN 1754-0739 (in press)

Nagai Y, Biofeedback Treatment. In Kanemoto H et al. Clinical Epilepsy. Igakushoin (in press).

Nagai Y. Biofeedback treatment for epilepsy. Nihon-Rinsho (Japanese), 2014, 72:887-893.

Nagai Y and Trimble MR. Long-term effects of electrodermal biofeedback training on seizure control in patients with drug-resistant epilepsy: Two case reports. Epilepsy Research, 2014, 108: 149-52.

Nagai Y, Cavanna AE, Critchley HD, Stern JS, Robertson MM, Joyce EM. Biofeedback treatment for Tourette Syndrome: Preliminary randomized controlled trial. Cogn Behav Neurol. 2014, 27:17-24.

Nagai Y and Trimble MR, Biofeedback treatment and seizure control. In Mostfsky D (Ed), Hand book of Behavioural Medichine. Wiley-Blackwell, 2014, 149-152.

Eugenia Radulescu, Yoko Nagai, Hugo Critchley. Mental effort: Brain and autonomic correlates in health and disease. In Biobehavioural foundation of self regulation. Eds Guido Gendolla, Mattie Tops and Sander Koole. Springer. 2014

Garfinkel S, Nagai Y, Seth A, Critchley H. Neuroimaging studies of introception and self-awareness. In Neuroimaging of consciousness. Cavanna AE eds. Springer, 2013, 207-224

Gray MA, Beacher FD, Minati L, Nagai Y, Kemp AH, Harrison HA, Critchley HD. Emotional appraisal is influenced by cardiac afferent information. Emotion 2012, 12, 180-91.

Critchley HD, Nagai Y How emotions are shaped by bodily state. Emotion Review, 2012, 2, 163-68.

Critchley HD and Nagai Y, Electrodermal activity and behavioral medicine. In Gellman MD (Ed), Encyclopedia of Behavioral Medicine. Springer, 2012 online
Gray M, Nagai Y, Critchley HD. Brain imaging of stress and cardiovascular responses. In Stress and Cardiovascular Disease. Springer (UK), 2012, 129-148.

Nagai Y. Biofeedback and epilepsy. Curr Neurol Neurosci Rep, 2011, 11, 433-450.

Nagai Y, Matsuura M. Review of biofeedback treatment on epilepsy (Japanese). 2011, Brain and Nerve, 63, 385-392.

Critchley HD, Nagai Y, Gray MA, Matias CJ. Dissecting axes of autonomic control in humans: Insights fromneuroimaging. Autonomic Neuroscience. 2011, 26, 34-42.

Nagai Y, Cavanna A, Critchley HD. Influence of sympathetic autonomic arousal on tics: Implication for a therapeutic behavioural intervention for Tourette Syndrome. Journal of Psychosomatic Research, 2009, 67, 599-605.

Nagai Y, Critchley HD, Rothwell JC, Duncan JS, Trimble MR. Changes in cortical potential associated with modulation of peripheral sympathetic activity in patients with epilepsy. Psychosomatic Medicine 2009, 71: 84-92.

Nagai Y. New research on biofeedback for seizure control. Encyclopedia of basic epilepsy research. Elsevier, 2009, Vol3 pp 1461-68.

Nagai Y. Biofeedback treatment for epilepsy in the UK (Japanese). Epilepsy, 2008 2: 53-58.

Nagai, Y. & Critchley, H.D. Novel application of Galvanic Skin Response (GSR) biofeedback to neurological disorder: Mechanisms underlying biofeedback in epilepsy management. In: Takahashi K (Ed), Progress in Epilepsy Research. Nova Science Publishers, 2008, pp 175-205.

Nagai, Y. Behavioral treatment for epilepsy. In: New Research on Epilepsy and Behavior. Nova Science Publishers, 2007,pp 279-294.

Nagai, Y. & Critchley, H.D. Novel application of Galvanic Skin Response (GSR) biofeedback to neurological disorders: Mechanisms underlying biofeedback in epilepsy management. In: New Research in Biofeedback. Nova Publishers, 2007, pp 1-31.

Critchley HD, Rotshtein P, Nagai Y, O’Doherty J, Mathias CJ, Dolan RJ. Activity in the human brain predicting differential autonomic heart rate responses to emotional facial expressions. Neuroimage 2005, 24:751-62.

Nagai Y, Goldstein LH, Fenwick PBC, Trimble MR. Clinical efficacy of biofeedback treatment on reducing seizures in adult epilepsy: a preliminary randomized controlled study. Epilepsy & Behaviour 2004, Vol 5/2: 216-223.

Nagai Y, Critchley HD, Featherstone E, Fenwick PBC, Trimble MR, Dolan RJ. Brain activity relating to the Contingent Negative Variation (CNV): fMRI investigation. Neuroimage 2004, 21:1232-1241.

Nagai Y, Critchley HD, Featherstone E, Trimble MR, Dolan RJ. Activity in ventromedial prefrontal cortex covaries with sympathetic skin conductance level (SCL): a physiological account of a “default mode” of brain function.

Neuroimage 2004, 22:243-251.

Nagai Y, Goldstein LH, Critchley HD, Fenwick PBC. Influence of sympathetic autonomic arousal on contingent negative variation: implications for a therapeutic behavioural intervention in epilepsy. Epilepsy Res 2004, 58:185-193.