| 1. |
- Jakabek, David, et al.
(författare)
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Regional structural hypo- and hyperconnectivity of frontal–striatal and frontal–thalamic pathways in behavioral variant frontotemporal dementia
- 2018
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Ingår i: Human Brain Mapping. - : Wiley. - 1065-9471. ; 39:10, s. 4083-4093
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Tidskriftsartikel (refereegranskat)abstract
- Behavioral variant frontotemporal dementia (bvFTD) has been predominantly considered as a frontotemporal cortical disease, with limited direct investigation of frontal–subcortical connections. We aim to characterize the grey and white matter components of frontal–thalamic and frontal–striatal circuits in bvFTD. Twenty-four patients with bvFTD and 24 healthy controls underwent morphological and diffusion imaging. Subcortical structures were manually segmented according to published protocols. Probabilistic pathways were reconstructed separately from the dorsolateral, orbitofrontal and medial prefrontal cortex to the striatum and thalamus. Patients with bvFTD had smaller cortical and subcortical volumes, lower fractional anisotropy, and higher mean diffusivity metrics, which is consistent with disruptions in frontal–striatal–thalamic pathways. Unexpectedly, regional volumes of the striatum and thalamus connected to the medial prefrontal cortex were significantly larger in bvFTD (by 135% in the striatum, p =.032, and 217% in the thalamus, p =.004), despite smaller dorsolateral prefrontal cortex connected regional volumes (by 67% in the striatum, p =.002, and 65% in the thalamus, p =.020), and inconsistent changes in orbitofrontal cortex connected regions. These unanticipated findings may represent compensatory or maladaptive remodeling in bvFTD networks. Comparisons are made to other neuropsychiatric disorders suggesting a common mechanism of changes in frontal–subcortical networks; however, longitudinal studies are necessary to test this hypothesis.
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| 2. |
- Macfarlane, Matthew D, et al.
(författare)
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Striatal Atrophy in the Behavioural Variant of Frontotemporal Dementia: Correlation with Diagnosis, Negative Symptoms and Disease Severity.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Behavioural variant frontotemporal dementia (bvFTD) is associated with changes in dorsal striatal parts of the basal ganglia (caudate nucleus and putamen), related to dysfunction in the cortico-striato-thalamic circuits which help mediate executive and motor functions. We aimed to determine whether the size and shape of striatal structures correlated with diagnosis of bvFTD, and measures of clinical severity, behaviour and cognition.
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| 3. |
- Power, Brian D., et al.
(författare)
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Morphometric analysis of thalamic volume in progressive supranuclear palsy : In vivo evidence of regionally specific bilateral thalamic atrophy
- 2017
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Ingår i: Psychiatry Research - Neuroimaging. - : Elsevier BV. - 0925-4927. ; 265, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- We investigated whether differences were detectable in the volume and shape of the dorsal thalamus on magnetic resonance imaging in patients with progressive supranuclear palsy (PSP). Manual segmentation of the left and right thalami on magnetic resonance imaging scans occurred in 22 patients with clinically diagnosed PSP and 23 healthy controls; thalamic volumes (left, right, total) were calculated. Between group differences were explored by multivariate analysis of co-variance, using age and intracranial volume as covariates. Analysis of the shape of the thalamus was performed using the spherical harmonic point distribution method software package. Patients with PSP were found to have significant bilateral thalamic atrophy on magnetic resonance imaging; there was significant shape deflation over the anterior-lateral and anterior-ventral surfaces bilaterally, and over the right caudal thalamus. Recognizing decreased thalamic morphology in PSP patients in vivo may be an important component of an ensemble of diagnostic biomarkers in the future, particularly given the difficulty of distinguishing PSP from other Parkinsonian conditions early in the disease course.
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| 4. |
- Power, Brian D, et al.
(författare)
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Validation of a protocol for manual segmentation of the thalamus on magnetic resonance imaging scans.
- 2015
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Ingår i: Psychiatry Research. - : Elsevier BV. - 1872-7123 .- 0925-4927. ; 232:1, s. 98-105
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Tidskriftsartikel (refereegranskat)abstract
- We present a validated protocol for manual segmentation of the thalamus on T1-weighted magnetic resonance imaging (MRI) scans using brain image analysis software. The MRI scans of five normal control subjects were randomly selected from a larger cohort recruited from Lund University Hospital and Landskrona Hospital, Sweden. MRIs were performed using a 3.0T Philips MR scanner, with an eight-channel head coil, and high resolution images were acquired using a T1-weighted turbo field echo (T1 TFE) pulse sequence, with resulting voxel size 1×1×1mm(3). Manual segmentation of the left and right thalami and volume measurement was performed on 28-30 contiguous coronal slices, using ANALYZE 11.0 software. Reliability of image analysis was performed by measuring intra-class correlations between initial segmentation and random repeated segmentation of the left and right thalami (in total 10 thalami for segmentation); inter-rater reliability was measured using volumes obtained by two other experienced tracers. Intra-class correlations for two independent raters were 0.95 and 0.98; inter-class correlations between the expert rater and two independent raters were 0.92 and 0.98. We anticipate that mapping thalamic morphology in various neuropsychiatric disorders may yield clinically useful disease-specific biomarkers.
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