Thalamocortical dysrhythmia in photosensitive epilepsy

D. Brazzo, G. di Lorenzo, S. Seri

Research output: Contribution to journalMeeting abstract

Abstract

Purpose: To provide experimental support to the hypothesis of a possible disruption in the physiological thalamic regulation of cortico-cortical synchronisation - thalamocortical dysrhythmia (TCD) - in the pathophysiology of photosensitive epilepsy (PSE).
Method: 16 subjects, 8 with PSE and 8 healthy volunteers (CTR) with no history of neurological disorders entered the study. Data was acquired with a 128-channel dense array EEG and a 306 sensor MEG. Horizontal stationary sinusoidal gratings with spatial frequency of 3 cycles per degree (cpd) were presented for a 4 sec ‘‘on’’ period, followed by a 4 sec ‘‘off’’ period during which a full field equiluminant screen was shown. Independent Component Analysis (ICA) and time-frequency analysis of the extracted components were carried out, followed by cluster analysis on the components map.
Result: Clusters of components with clear dipolar pattern in the occipital region exhibited the following features: 1- evoked and induced gamma band (25–60 Hz) in PSE and CTR groups, without statistically significant differences between the two groups; 2- sustained desynchronisation in the alpha- beta bands (8–20 Hz) only in the CTR group; 3- statistically significant phase locked and sustained synchronisation (power increase) in the theta band (4–8 Hz) in the PSE group.
Conclusion: Abnormal theta synchronisation can be interpreted as the electrophysiological correlate of disordered connection between thalamus and occipital cortex in PSE, in line with TCD model. TCD rather than a syndrome, as proposed in several studies, could be a shared mechanism in a number of pathological conditions including PSE.
Original languageEnglish
Article numberp432
Pages (from-to)127
Number of pages1
JournalEpilepsia
Volume53
Issue numbers5
DOIs
Publication statusPublished - 11 Sep 2012
Event10th European Congress on Epileptology - London, United Kingdom
Duration: 30 Sep 20124 Oct 2012

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Reflex Epilepsy
Occipital Lobe
Cortical Synchronization
Nervous System Diseases
Thalamus
Cluster Analysis
Electroencephalography
Healthy Volunteers

Bibliographical note

Special Issue: 10 European Congress on Epileptology, London, UK, 30 September - 4 October, 2012.

Cite this

Brazzo, D. ; di Lorenzo, G. ; Seri, S. / Thalamocortical dysrhythmia in photosensitive epilepsy. In: Epilepsia. 2012 ; Vol. 53, No. s5. pp. 127.
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abstract = "Purpose: To provide experimental support to the hypothesis of a possible disruption in the physiological thalamic regulation of cortico-cortical synchronisation - thalamocortical dysrhythmia (TCD) - in the pathophysiology of photosensitive epilepsy (PSE).Method: 16 subjects, 8 with PSE and 8 healthy volunteers (CTR) with no history of neurological disorders entered the study. Data was acquired with a 128-channel dense array EEG and a 306 sensor MEG. Horizontal stationary sinusoidal gratings with spatial frequency of 3 cycles per degree (cpd) were presented for a 4 sec ‘‘on’’ period, followed by a 4 sec ‘‘off’’ period during which a full field equiluminant screen was shown. Independent Component Analysis (ICA) and time-frequency analysis of the extracted components were carried out, followed by cluster analysis on the components map.Result: Clusters of components with clear dipolar pattern in the occipital region exhibited the following features: 1- evoked and induced gamma band (25–60 Hz) in PSE and CTR groups, without statistically significant differences between the two groups; 2- sustained desynchronisation in the alpha- beta bands (8–20 Hz) only in the CTR group; 3- statistically significant phase locked and sustained synchronisation (power increase) in the theta band (4–8 Hz) in the PSE group.Conclusion: Abnormal theta synchronisation can be interpreted as the electrophysiological correlate of disordered connection between thalamus and occipital cortex in PSE, in line with TCD model. TCD rather than a syndrome, as proposed in several studies, could be a shared mechanism in a number of pathological conditions including PSE.",
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Thalamocortical dysrhythmia in photosensitive epilepsy. / Brazzo, D.; di Lorenzo, G.; Seri, S.

In: Epilepsia, Vol. 53, No. s5, p432, 11.09.2012, p. 127.

Research output: Contribution to journalMeeting abstract

TY - JOUR

T1 - Thalamocortical dysrhythmia in photosensitive epilepsy

AU - Brazzo, D.

AU - di Lorenzo, G.

AU - Seri, S.

N1 - Special Issue: 10 European Congress on Epileptology, London, UK, 30 September - 4 October, 2012.

PY - 2012/9/11

Y1 - 2012/9/11

N2 - Purpose: To provide experimental support to the hypothesis of a possible disruption in the physiological thalamic regulation of cortico-cortical synchronisation - thalamocortical dysrhythmia (TCD) - in the pathophysiology of photosensitive epilepsy (PSE).Method: 16 subjects, 8 with PSE and 8 healthy volunteers (CTR) with no history of neurological disorders entered the study. Data was acquired with a 128-channel dense array EEG and a 306 sensor MEG. Horizontal stationary sinusoidal gratings with spatial frequency of 3 cycles per degree (cpd) were presented for a 4 sec ‘‘on’’ period, followed by a 4 sec ‘‘off’’ period during which a full field equiluminant screen was shown. Independent Component Analysis (ICA) and time-frequency analysis of the extracted components were carried out, followed by cluster analysis on the components map.Result: Clusters of components with clear dipolar pattern in the occipital region exhibited the following features: 1- evoked and induced gamma band (25–60 Hz) in PSE and CTR groups, without statistically significant differences between the two groups; 2- sustained desynchronisation in the alpha- beta bands (8–20 Hz) only in the CTR group; 3- statistically significant phase locked and sustained synchronisation (power increase) in the theta band (4–8 Hz) in the PSE group.Conclusion: Abnormal theta synchronisation can be interpreted as the electrophysiological correlate of disordered connection between thalamus and occipital cortex in PSE, in line with TCD model. TCD rather than a syndrome, as proposed in several studies, could be a shared mechanism in a number of pathological conditions including PSE.

AB - Purpose: To provide experimental support to the hypothesis of a possible disruption in the physiological thalamic regulation of cortico-cortical synchronisation - thalamocortical dysrhythmia (TCD) - in the pathophysiology of photosensitive epilepsy (PSE).Method: 16 subjects, 8 with PSE and 8 healthy volunteers (CTR) with no history of neurological disorders entered the study. Data was acquired with a 128-channel dense array EEG and a 306 sensor MEG. Horizontal stationary sinusoidal gratings with spatial frequency of 3 cycles per degree (cpd) were presented for a 4 sec ‘‘on’’ period, followed by a 4 sec ‘‘off’’ period during which a full field equiluminant screen was shown. Independent Component Analysis (ICA) and time-frequency analysis of the extracted components were carried out, followed by cluster analysis on the components map.Result: Clusters of components with clear dipolar pattern in the occipital region exhibited the following features: 1- evoked and induced gamma band (25–60 Hz) in PSE and CTR groups, without statistically significant differences between the two groups; 2- sustained desynchronisation in the alpha- beta bands (8–20 Hz) only in the CTR group; 3- statistically significant phase locked and sustained synchronisation (power increase) in the theta band (4–8 Hz) in the PSE group.Conclusion: Abnormal theta synchronisation can be interpreted as the electrophysiological correlate of disordered connection between thalamus and occipital cortex in PSE, in line with TCD model. TCD rather than a syndrome, as proposed in several studies, could be a shared mechanism in a number of pathological conditions including PSE.

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DO - 10.1111/j.1528-1167.2012.03677.x

M3 - Meeting abstract

VL - 53

SP - 127

JO - Epilepsia

JF - Epilepsia

SN - 0013-9580

IS - s5

M1 - p432

ER -