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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

Scatterplots depicting the distribution of ROI tensor-based morphometry values as a function of the six-month GOS (with confidence ellipsis). Spearman's rank correlation coefficient ‘ρ’ is reported, for each variable; ‘***’ indicates p < 0.001; ‘*’ indicates 0.05 ≤ p ≤ 0.01; ‘†’ indicates p = 0.06; ‘n.s.’ indicates not significant.
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f0015: Scatterplots depicting the distribution of ROI tensor-based morphometry values as a function of the six-month GOS (with confidence ellipsis). Spearman's rank correlation coefficient ‘ρ’ is reported, for each variable; ‘***’ indicates p < 0.001; ‘*’ indicates 0.05 ≤ p ≤ 0.01; ‘†’ indicates p = 0.06; ‘n.s.’ indicates not significant.

Mentions: As shown in Fig. 3, however, only for a few ROIs the degree of atrophy was significantly correlated with the six-month outcome. When corrected for multiple comparisons, only one nucleus exhibited a significant association with the six-month GOSe, the AN, which correlated positively with the outcome measure (ρ = 0.46, p < 0.001). Considering that the TBM values in this nucleus are mostly negative (cf., Table 2 and Fig. 3), this association is best interpreted as implying that the less the atrophy in this nucleus the better the outcome. The DMN and LDN also exhibited the same pattern of association with the outcome measure (ρ = 0.31, p ≈ 0.03, for both ROIs), although neither met family-wise Bonferroni criterion. One ROI exhibited the reverse association (although it did not reach Bonferroni criterion). Namely, the MGN exhibited a significant negative correlation with the six-month GOSe score (ρ = − 0.34, p ≈ 0.02). Considering that values in this ROI are mostly positive (cf., Table 2 and Fig. 3), this association is best interpreted as implying that the less the tissue expansion in this region the better the outcome. Finally, the VLPN also exhibited this same pattern of association, but was only marginally significant at the individual test level (ρ = − 0.27, p ≈ 0.06), and thus also did not survive family-wise statistical correction.


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)

Scatterplots depicting the distribution of ROI tensor-based morphometry values as a function of the six-month GOS (with confidence ellipsis). Spearman's rank correlation coefficient ‘ρ’ is reported, for each variable; ‘***’ indicates p < 0.001; ‘*’ indicates 0.05 ≤ p ≤ 0.01; ‘†’ indicates p = 0.06; ‘n.s.’ indicates not significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f0015: Scatterplots depicting the distribution of ROI tensor-based morphometry values as a function of the six-month GOS (with confidence ellipsis). Spearman's rank correlation coefficient ‘ρ’ is reported, for each variable; ‘***’ indicates p < 0.001; ‘*’ indicates 0.05 ≤ p ≤ 0.01; ‘†’ indicates p = 0.06; ‘n.s.’ indicates not significant.
Mentions: As shown in Fig. 3, however, only for a few ROIs the degree of atrophy was significantly correlated with the six-month outcome. When corrected for multiple comparisons, only one nucleus exhibited a significant association with the six-month GOSe, the AN, which correlated positively with the outcome measure (ρ = 0.46, p < 0.001). Considering that the TBM values in this nucleus are mostly negative (cf., Table 2 and Fig. 3), this association is best interpreted as implying that the less the atrophy in this nucleus the better the outcome. The DMN and LDN also exhibited the same pattern of association with the outcome measure (ρ = 0.31, p ≈ 0.03, for both ROIs), although neither met family-wise Bonferroni criterion. One ROI exhibited the reverse association (although it did not reach Bonferroni criterion). Namely, the MGN exhibited a significant negative correlation with the six-month GOSe score (ρ = − 0.34, p ≈ 0.02). Considering that values in this ROI are mostly positive (cf., Table 2 and Fig. 3), this association is best interpreted as implying that the less the tissue expansion in this region the better the outcome. Finally, the VLPN also exhibited this same pattern of association, but was only marginally significant at the individual test level (ρ = − 0.27, p ≈ 0.06), and thus also did not survive family-wise statistical correction.

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