Analysis of automated methods for spatial normalization of lesioned brains

Ripollés, Pablo; Marco-Pallarés, Josep; Diego‐Balaguer, Ruth de; Miró, Júlia; Falip, Mercé; Juncadella, Montserrat; Rubio, Francisco; Rodrı́guez-Fornells, Antoni

doi:10.1016/j.neuroimage.2012.01.094

Cited by 135 publications

(117 citation statements)

References 24 publications

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“…VBM, based on DARTEL, is an established and widely used technique to assess differences in brain structure and has been shown to operate well in cases of relatively mild-to-severe structural brain injury [65,66]. In many cases, structural brain injury in patients with DOC belongs to the most severe class of structural brain injury, with brains often showing great morphological changes like ventricle enlargement [65].…”

Section: Methodological Considerationsmentioning

confidence: 99%

“…In many cases, structural brain injury in patients with DOC belongs to the most severe class of structural brain injury, with brains often showing great morphological changes like ventricle enlargement [65]. Therefore, to minimize the chance of false results, a smoothing kernel of 12 mm was used and a patient specific DARTEL template was employed [67].…”

Section: Methodological Considerationsmentioning

confidence: 99%

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Structural brain injury in patients with disorders of consciousness: A voxel-based morphometry study

et al. 2016

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Main objective: Disorders of consciousness (DOC; encompassing coma, vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious state minus/plus (MCS-/+)) are associated with structural brain injury. The extent of this damage remains poorly understood and merits a detailed examination using novel analysis techniques. Research design/methods and procedures: This study used voxel-based morphometry (VBM) on structural magnetic resonance imaging scans of 61 patients with DOC to examine grey and white matter injury associated with DOC, time spent in DOC, aetiology and diagnosis. Main outcomes and results: DOC and time spent in DOC were found to be associated with widespread structural brain injury, although the latter did not correlate strongly with injury in the right cerebral hemisphere. Traumatic, as compared to non-traumatic aetiology, was related to more injury in the brainstem, midbrain, thalamus, hypothalamus, basal forebrain, cerebellum, and posterior corpus callosum. Potential structural differences were found between VS/ UWS and MCS and between MCS-and MCS+, but need further examination. Conclusions: The findings indicate that both traumatic and non-traumatic DOC are associated with widespread structural brain injury, although differences exist that could lead to aetiologyspecific treatment strategies. Furthermore, the high degree of atrophy occurring after initial brain injury prompts the development and use of neuroprotective techniques to potentially increase patients' chances of recovery. KeywordsVegetative state/unresponsive wakefulness syndrome, minimally conscious state, structural brain injury, voxel-based morphometry History

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Section: Methodological Considerationsmentioning

confidence: 99%

Section: Methodological Considerationsmentioning

confidence: 99%

Structural brain injury in patients with disorders of consciousness: A voxel-based morphometry study

et al. 2016

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“…Then, using each coregistered T1 scan, the normalization parameters needed to transform the data to MNI152 space were obtained by means of Unified Segmentation [33], which combines segmentation, bias correction and spatial normalization under the same iterative model. This method has been successfully applied to both healthy and patient populations [34]. Finally, normalized EPI images were resliced to 2 × 2 × 2 mm and smoothed with an 8 mm full-width at half-maximum isotropic Gaussian kernel.…”

Section: Methodsmentioning

confidence: 99%

Atypical language organization in temporal lobe epilepsy revealed by a passive semantic paradigm

et al. 2014

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BackgroundMesial temporal lobe epilepsy (MTLE) is the most common type of focal epilepsy in adults and can be successfully cured by surgery. One of the main complications of this surgery however is a decline in language abilities. The magnitude of this decline is related to the degree of language lateralization to the left hemisphere. Most fMRI paradigms used to determine language dominance in epileptic populations have used active language tasks. Sometimes, these paradigms are too complex and may result in patient underperformance. Only a few studies have used purely passive tasks, such as listening to standard speech.MethodsIn the present study we characterized language lateralization in patients with MTLE using a rapid and passive semantic language task. We used functional magnetic resonance imaging (fMRI) to study 23 patients [12 with Left (LMTLE), 11 with Right mesial temporal lobe epilepsy (RMTLE)] and 19 healthy right-handed controls using a 6 minute long semantic task in which subjects passively listened to groups of sentences (SEN) and pseudo sentences (PSEN). A lateralization index (LI) was computed using a priori regions of interest of the temporal lobe.ResultsThe LI for the significant contrasts produced activations for all participants in both temporal lobes. 81.8% of RMTLE patients and 79% of healthy individuals had a bilateral language representation for this particular task. However, 50% of LMTLE patients presented an atypical right hemispheric dominance in the LI. More importantly, the degree of right lateralization in LMTLE patients was correlated with the age of epilepsy onset.ConclusionsThe simple, rapid, non-collaboration dependent, passive task described in this study, produces a robust activation in the temporal lobe in both patients and controls and is capable of illustrating a pattern of atypical language organization for LMTLE patients. Furthermore, we observed that the atypical right-lateralization patterns in LMTLE patients was associated to earlier age at epilepsy onset. These results are in line with the idea that early onset of epileptic activity is associated to larger neuroplastic changes.

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“…All subjects were then re-registered onto the template images, using constrained cost-function masking (CCFM) of the lesions, which were manually traced (DSG) for each case. CCFM has been shown to substantially improve the mapping of lesioned brain data (Andersen et al 2010), particularly when used with ANTS-SyN (Ripolles et al 2012). Regional and voxelwise morphometric analyses were conducted on the 12-year dataset to facilitate comparison with the DWI analyses.…”

Section: Study-specific Template Constructionmentioning

confidence: 99%

Neural Reorganization Due to Neonatal Amygdala Lesions in the Rhesus Monkey: Changes in Morphology and Network Structure

et al. 2017

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It is generally believed that neural damage that occurs early in development is associated with greater adaptive capacity relative to similar damage in an older individual. However, few studies have surveyed whole brain changes following early focal damage. In this report, we employed multimodal magnetic resonance imaging analyses of adult rhesus macaque monkeys who had previously undergone bilateral, neurotoxic lesions of the amygdala at about 2 weeks of age. A deformation-based morphometric approach demonstrated reduction of the volumes of the anterior temporal lobe, anterior commissure, basal ganglia, and pulvinar in animals with early amygdala lesions compared to controls. In contrast, animals with early amygdala lesions had an enlarged cingulate cortex, medial superior frontal gyrus, and medial parietal cortex. Diffusion-weighted imaging tractography and network analysis were also used to compare connectivity patterns and higher-level measures of communication across the brain. Using the communicability metric, which integrates direct and indirect paths between regions, lesioned animals showed extensive degradation of network integrity in the temporal and orbitofrontal cortices. This work demonstrates both degenerative as well as progressive large-scale neural changes following long-term recovery from neonatal focal brain damage.

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Analysis of automated methods for spatial normalization of lesioned brains

Cited by 135 publications

References 24 publications

Structural brain injury in patients with disorders of consciousness: A voxel-based morphometry study

Structural brain injury in patients with disorders of consciousness: A voxel-based morphometry study

Atypical language organization in temporal lobe epilepsy revealed by a passive semantic paradigm

Neural Reorganization Due to Neonatal Amygdala Lesions in the Rhesus Monkey: Changes in Morphology and Network Structure

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