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Thalamic atrophy in antero-medial and dorsal nuclei correlates with six-month outcome after severe brain injury.

Lutkenhoff ES, McArthur DL, Hua X, Thompson PM, Vespa PM, Monti MM - Neuroimage Clin (2013)

Bottom Line: The secondary processes, in particular, are of great clinical interest because of their potential susceptibility to intervention.Using tensor-based morphometry, we observed significant localized thalamic atrophy over the six-month period in antero-dorsal limbic nuclei as well as in medio-dorsal association nuclei.Furthermore, employing a data-driven decision tree model, we found that physiological measures, namely the extent of atrophy in the anterior thalamic nucleus, were the most predictive variables of whether patients had regained consciousness by six-months, followed by behavioral measures.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of California Los Angeles, Los Angeles, CA 90095, USA.

ABSTRACT
The primary and secondary damage to neural tissue inflicted by traumatic brain injury is a leading cause of death and disability. The secondary processes, in particular, are of great clinical interest because of their potential susceptibility to intervention. We address the dynamics of tissue degeneration in cortico-subcortical circuits after severe brain injury by assessing volume change in individual thalamic nuclei over the first six-months post-injury in a sample of 25 moderate to severe traumatic brain injury patients. Using tensor-based morphometry, we observed significant localized thalamic atrophy over the six-month period in antero-dorsal limbic nuclei as well as in medio-dorsal association nuclei. Importantly, the degree of atrophy in these nuclei was predictive, even after controlling for full-brain volume change, of behavioral outcome at six-months post-injury. Furthermore, employing a data-driven decision tree model, we found that physiological measures, namely the extent of atrophy in the anterior thalamic nucleus, were the most predictive variables of whether patients had regained consciousness by six-months, followed by behavioral measures. Overall, these findings suggest that the secondary non-mechanical degenerative processes triggered by severe brain injury are still ongoing after the first week post-trauma and target specifically antero-medial and dorsal thalamic nuclei. This result therefore offers a potential window of intervention, and a specific target region, in agreement with the view that specific cortico-thalamo-cortical circuits are crucial to the maintenance of large-scale network neural activity and thereby the restoration of cognitive function after severe brain injury.

No MeSH data available.


Related in: MedlinePlus

ROI parcellation of thalamus (ICBM Thalamic Atlas; Mazziotta et al., 2001). Abrv.: AN, anterior nucleus; VAN, ventral anterior nucleus; VLN, ventral lateral nucleus; VPLN, ventral posterolateral nucleus; DMN, dorsomedial; LDN, lateral dorsal nucleus; LPN, lateral posterior nucleus; PlvN, pulvinar nucleus; MGN, medial geniculate nucleus; LGN, lateral geniculate nucleus. (VPMN, ventral posteromedial nucleus, not shown.)
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f0005: ROI parcellation of thalamus (ICBM Thalamic Atlas; Mazziotta et al., 2001). Abrv.: AN, anterior nucleus; VAN, ventral anterior nucleus; VLN, ventral lateral nucleus; VPLN, ventral posterolateral nucleus; DMN, dorsomedial; LDN, lateral dorsal nucleus; LPN, lateral posterior nucleus; PlvN, pulvinar nucleus; MGN, medial geniculate nucleus; LGN, lateral geniculate nucleus. (VPMN, ventral posteromedial nucleus, not shown.)

Mentions: For each patient, right and left thalami were segmented into 11 structurally defined regions of interest (ROI) on the basis of the ICBM Deep Nuclei Probabilistic Atlas (see Fig. 1; Mazziotta et al., 2001). ROIs included the anterior nucleus (AN), ventral anterior (VAN), ventral lateral (VLN), ventral posteromedial (VPMN), ventral posterolateral (VPLN), dorsomedial (DMN), lateral dorsal (LDN), lateral posterior (LPN), pulvinar (PlvN), medial geniculate (MGN), and lateral geniculate (LGN) nuclei. Individual ICBM thalamic labels were registered to each patient's acute MP-RAGE image, and the corresponding Jacobian map values were averaged within each ROI. To ensure accurate registration of the ICBM thalamic labels to each subjects space, the following 3-step procedure was implemented: (1) Each subject's acute scan was registered to the MNI152 space employing a subcortically tuned algorithm (“first flirt,” part of the FSL suite; Jenkinson and Smith, 2001) that uses a subcortical mask for weighting; (2) The MNI152 image was then registered to the ICBM Template image; (3) The two matrices obtained from steps 1 and 2 were concatenated, inverted and applied to the ICBM thalamic labels in order to transform them into individual subject space. All resulting ROIs were visually inspected to ensure registration effectiveness.


Thalamic atrophy in antero-medial and dorsal nuclei correlates with six-month outcome after severe brain injury.

Lutkenhoff ES, McArthur DL, Hua X, Thompson PM, Vespa PM, Monti MM - Neuroimage Clin (2013)

ROI parcellation of thalamus (ICBM Thalamic Atlas; Mazziotta et al., 2001). Abrv.: AN, anterior nucleus; VAN, ventral anterior nucleus; VLN, ventral lateral nucleus; VPLN, ventral posterolateral nucleus; DMN, dorsomedial; LDN, lateral dorsal nucleus; LPN, lateral posterior nucleus; PlvN, pulvinar nucleus; MGN, medial geniculate nucleus; LGN, lateral geniculate nucleus. (VPMN, ventral posteromedial nucleus, not shown.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3815017&req=5

f0005: ROI parcellation of thalamus (ICBM Thalamic Atlas; Mazziotta et al., 2001). Abrv.: AN, anterior nucleus; VAN, ventral anterior nucleus; VLN, ventral lateral nucleus; VPLN, ventral posterolateral nucleus; DMN, dorsomedial; LDN, lateral dorsal nucleus; LPN, lateral posterior nucleus; PlvN, pulvinar nucleus; MGN, medial geniculate nucleus; LGN, lateral geniculate nucleus. (VPMN, ventral posteromedial nucleus, not shown.)
Mentions: For each patient, right and left thalami were segmented into 11 structurally defined regions of interest (ROI) on the basis of the ICBM Deep Nuclei Probabilistic Atlas (see Fig. 1; Mazziotta et al., 2001). ROIs included the anterior nucleus (AN), ventral anterior (VAN), ventral lateral (VLN), ventral posteromedial (VPMN), ventral posterolateral (VPLN), dorsomedial (DMN), lateral dorsal (LDN), lateral posterior (LPN), pulvinar (PlvN), medial geniculate (MGN), and lateral geniculate (LGN) nuclei. Individual ICBM thalamic labels were registered to each patient's acute MP-RAGE image, and the corresponding Jacobian map values were averaged within each ROI. To ensure accurate registration of the ICBM thalamic labels to each subjects space, the following 3-step procedure was implemented: (1) Each subject's acute scan was registered to the MNI152 space employing a subcortically tuned algorithm (“first flirt,” part of the FSL suite; Jenkinson and Smith, 2001) that uses a subcortical mask for weighting; (2) The MNI152 image was then registered to the ICBM Template image; (3) The two matrices obtained from steps 1 and 2 were concatenated, inverted and applied to the ICBM thalamic labels in order to transform them into individual subject space. All resulting ROIs were visually inspected to ensure registration effectiveness.

Bottom Line: The secondary processes, in particular, are of great clinical interest because of their potential susceptibility to intervention.Using tensor-based morphometry, we observed significant localized thalamic atrophy over the six-month period in antero-dorsal limbic nuclei as well as in medio-dorsal association nuclei.Furthermore, employing a data-driven decision tree model, we found that physiological measures, namely the extent of atrophy in the anterior thalamic nucleus, were the most predictive variables of whether patients had regained consciousness by six-months, followed by behavioral measures.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of California Los Angeles, Los Angeles, CA 90095, USA.

ABSTRACT
The primary and secondary damage to neural tissue inflicted by traumatic brain injury is a leading cause of death and disability. The secondary processes, in particular, are of great clinical interest because of their potential susceptibility to intervention. We address the dynamics of tissue degeneration in cortico-subcortical circuits after severe brain injury by assessing volume change in individual thalamic nuclei over the first six-months post-injury in a sample of 25 moderate to severe traumatic brain injury patients. Using tensor-based morphometry, we observed significant localized thalamic atrophy over the six-month period in antero-dorsal limbic nuclei as well as in medio-dorsal association nuclei. Importantly, the degree of atrophy in these nuclei was predictive, even after controlling for full-brain volume change, of behavioral outcome at six-months post-injury. Furthermore, employing a data-driven decision tree model, we found that physiological measures, namely the extent of atrophy in the anterior thalamic nucleus, were the most predictive variables of whether patients had regained consciousness by six-months, followed by behavioral measures. Overall, these findings suggest that the secondary non-mechanical degenerative processes triggered by severe brain injury are still ongoing after the first week post-trauma and target specifically antero-medial and dorsal thalamic nuclei. This result therefore offers a potential window of intervention, and a specific target region, in agreement with the view that specific cortico-thalamo-cortical circuits are crucial to the maintenance of large-scale network neural activity and thereby the restoration of cognitive function after severe brain injury.

No MeSH data available.


Related in: MedlinePlus