The Default Mode Network and Altered Consciousness in Epilepsy
The default mode network has been hypothesized based on the observation that specific regions of the brain are consistently activated during the resting state and deactivated during engagement with task. The primary nodes of this network, which typically include the precuneus/posterior cingulate, th...
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| Format: | Article |
| Language: | English |
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Wiley
2011-01-01
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| Series: | Behavioural Neurology |
| Online Access: | http://dx.doi.org/10.3233/BEN-2011-0310 |
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| author | Nathan B. Danielson Jennifer N. Guo Hal Blumenfeld |
| author_facet | Nathan B. Danielson Jennifer N. Guo Hal Blumenfeld |
| author_sort | Nathan B. Danielson |
| collection | DOAJ |
| description | The default mode network has been hypothesized based on the observation that specific regions of the brain are consistently activated during the resting state and deactivated during engagement with task. The primary nodes of this network, which typically include the precuneus/posterior cingulate, the medial frontal and lateral parietal cortices, are thought to be involved in introspective and social cognitive functions. Interestingly, this same network has been shown to be selectively impaired during epileptic seizures associated with loss of consciousness. Using a wide range of neuroimaging and electrophysiological modalities, decreased activity in the default mode network has been confirmed during complex partial, generalized tonic-clonic, and absence seizures. In this review we will discuss these three seizure types and will focus on possible mechanisms by which decreased default mode network activity occurs. Although the specific mechanisms of onset and propagation differ considerably across these seizure types, we propose that the resulting loss of consciousness in all three types of seizures is due to active inhibition of subcortical arousal systems that normally maintain default mode network activity in the awake state. Further, we suggest that these findings support a general “network inhibition hypothesis”, by which active inhibition of arousal systems by seizures in certain cortical regions leads to cortical deactivation in other cortical areas. This may represent a push-pull mechanism similar to that seen operating between cortical networks under normal conditions. |
| format | Article |
| id | doaj-art-6b1f831655bd4f84a233a144c3ac589c |
| institution | Kabale University |
| issn | 0953-4180 1875-8584 |
| language | English |
| publishDate | 2011-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Behavioural Neurology |
| spelling | doaj-art-6b1f831655bd4f84a233a144c3ac589c2025-02-03T06:44:01ZengWileyBehavioural Neurology0953-41801875-85842011-01-01241556510.3233/BEN-2011-0310The Default Mode Network and Altered Consciousness in EpilepsyNathan B. Danielson0Jennifer N. Guo1Hal Blumenfeld2Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USADepartment of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USADepartment of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USAThe default mode network has been hypothesized based on the observation that specific regions of the brain are consistently activated during the resting state and deactivated during engagement with task. The primary nodes of this network, which typically include the precuneus/posterior cingulate, the medial frontal and lateral parietal cortices, are thought to be involved in introspective and social cognitive functions. Interestingly, this same network has been shown to be selectively impaired during epileptic seizures associated with loss of consciousness. Using a wide range of neuroimaging and electrophysiological modalities, decreased activity in the default mode network has been confirmed during complex partial, generalized tonic-clonic, and absence seizures. In this review we will discuss these three seizure types and will focus on possible mechanisms by which decreased default mode network activity occurs. Although the specific mechanisms of onset and propagation differ considerably across these seizure types, we propose that the resulting loss of consciousness in all three types of seizures is due to active inhibition of subcortical arousal systems that normally maintain default mode network activity in the awake state. Further, we suggest that these findings support a general “network inhibition hypothesis”, by which active inhibition of arousal systems by seizures in certain cortical regions leads to cortical deactivation in other cortical areas. This may represent a push-pull mechanism similar to that seen operating between cortical networks under normal conditions.http://dx.doi.org/10.3233/BEN-2011-0310 |
| spellingShingle | Nathan B. Danielson Jennifer N. Guo Hal Blumenfeld The Default Mode Network and Altered Consciousness in Epilepsy Behavioural Neurology |
| title | The Default Mode Network and Altered Consciousness in Epilepsy |
| title_full | The Default Mode Network and Altered Consciousness in Epilepsy |
| title_fullStr | The Default Mode Network and Altered Consciousness in Epilepsy |
| title_full_unstemmed | The Default Mode Network and Altered Consciousness in Epilepsy |
| title_short | The Default Mode Network and Altered Consciousness in Epilepsy |
| title_sort | default mode network and altered consciousness in epilepsy |
| url | http://dx.doi.org/10.3233/BEN-2011-0310 |
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