Biomarker Commons

Stability of resting fMRI interregional correlations analyzed in subject-native space: a one-year longitudinal study in healthy adults and premanifest Huntington's disease.

Neuroimage. 2012 Feb 1;59(3):2452-63

Authors: Seibert TM, Majid DS, Aron AR, Corey-Bloom J, Brewer JB

Abstract
The pattern of interregional functional MRI correlations at rest is being actively considered as a potential noninvasive biomarker in multiple diseases. Before such methods can be used in clinical studies it is important to establish their usefulness in three ways. First, the long-term stability of resting correlation patterns should be characterized, but there have been very few such studies. Second, analysis of resting correlations should account for the unique neuroanatomy of each subject by taking measurements in native space and avoiding transformation of functional data to a standard volume space (e.g., Talairach-Tournox or Montreal Neurological Institute atlases). Transformation to a standard volume space has been shown to variably influence the measurement of functional correlations, and this is a particular concern in diseases which may cause structural changes in the brain. Third, comparisons within the patient population of interest and comparisons between patients and age-matched controls, should demonstrate sensitivity to any disease-related disruption of resting functional correlations. Here we examine the test-retest stability of resting fMRI correlations over a period of one year in a group of healthy adults and in a group of cognitively intact individuals who are gene-positive for Huntington's disease. A recently-developed method is used to measure functional correlations in the native space of individual subjects. The utility of resting functional correlations as a biomarker in premanifest Huntington's disease is also investigated. Results in control and premanifest Huntington's populations were both highly consistent at the group level over one year. We thus show that when resting fMRI analysis is performed in native space (to reduce confounds in registration between subjects and groups) it has good long-term stability at the group level. Individual-subject level results were less consistent between visit 1 and visit 2, suggesting further work is required before resting fMRI correlations can be useful diagnostically for individual patients. No significant effect of premanifest Huntington's disease on prespecified interregional fMRI correlations was observed relative to the control group using either baseline or longitudinal measures. Within the premanifest Huntington's group, though, there was evidence that decreased striatal functional correlations might be associated with disease severity, as gauged by estimated years to symptom onset or by striatal volume.

PMID: 21945695 [PubMed - indexed for MEDLINE]

MRI biomarkers in Huntington's disease.

Front Biosci (Elite Ed). 2012;4:1910-25

Authors: van den Bogaard S, Dumas E, van der Grond J, van Buchem M, Roos R

Abstract
Huntington's disease (HD) is a devastating neurodegenerative disease affecting the brain resulting in neuronal dysfunction and neuronal loss. Since the identification of the gene responsible for HD, genetic testing has become widely available, allowing for genetic status of persons at risk for HD to be determined. For the effective evaluation of future therapeutic trials a great need exists for sensitive biomarkers. In (premanifest) HD, MRI of the brain is one of the most logical candidates as a biomarker, as opposed to clinical measures, since brain neurons are the main target of the disease. These biomarkers can facilitate early detection of disease related changes, but are also needed to monitor disease progression from the premanifest phase of HD onwards. MRI derived parameters have this biomarker potential as they have been shown to identify brain abnormalities before symptom onset. In this review the available MRI techniques of conventional MRI, Diffusion Tensor Imaging, Magnetization Transfer Imaging, Magnetic Resonance Spectroscopy and Functional MRI will be discussed and the findings will be placed into context of different HD stages.

PMID: 22202007 [PubMed - indexed for MEDLINE]

Shape analysis of subcortical nuclei in Huntington's disease, global versus local atrophy--results from the TRACK-HD study.

J Neurol Sci. 2011 Aug 15;307(1-2):60-8

Authors: van den Bogaard SJ, Dumas EM, Ferrarini L, Milles J, van Buchem MA, van der Grond J, Roos RA

Abstract
Huntington's disease (HD) is characterized by brain atrophy. Localized atrophy of a specific structure could potentially be a more sensitive biomarker reflecting neuropathologic changes rather than global volume variation. We examined 90 TRACK-HD participants of which 30 were premanifest HD, 30 were manifest HD and 30 were controls. Using FMRIB's Integrated Registration and Segmentation Tool, segmentations were obtained for the pallidum, caudate nucleus, putamen, thalamus, accumbens nucleus, amygdala, and hippocampus and overall volumes were calculated. A point distribution model of each structure was obtained using Growing and Adaptive Meshes. Permutation testing between groups was performed to detect local displacement in shape between groups. In premanifest HD overall volume loss occurred in the putamen, accumbens and caudate nucleus. Overall volume reductions in manifest HD were found in all subcortical structures, except the amygdala, as compared to controls. In premanifest HD shape analysis showed small areas of displacement in the putamen, pallidum, accumbens and caudate nucleus. When the premanifest group was split into two groups according to predicted disease onset, the premanifest HD group close to expected disease onset showed more pronounced displacements in caudate nucleus and putamen compared to premanifest HD far from disease onset or the total premanifest group. Analysis of shape in manifest HD showed widespread shape differences, most prominently in the caudal part of the accumbens nucleus, body of the caudate nucleus, putamen and dorsal part of the pallidum. We conclude that shape analysis provides new insights in localized intrastructural atrophy patterns in HD, but can also potentially serve as specific target areas for disease tracking.

PMID: 21624624 [PubMed - indexed for MEDLINE]

Cortical metabolites as biomarkers in the R6/2 model of Huntington's disease.

J Cereb Blood Flow Metab. 2012 Mar;32(3):502-14

Authors: Zacharoff L, Tkac I, Song Q, Tang C, Bolan PJ, Mangia S, Henry PG, Li T, Dubinsky JM

Abstract
To improve the ability to move from preclinical trials in mouse models of Huntington's disease (HD) to clinical trials in humans, biomarkers are needed that can track similar aspects of disease progression across species. Brain metabolites, detectable by magnetic resonance spectroscopy (MRS), have been suggested as potential biomarkers in HD. In this study, the R6/2 transgenic mouse model of HD was used to investigate the relative sensitivity of the metabolite profiling and the brain volumetry to anticipate the disease progression. Magnetic resonance imaging (MRI) and (1)H MRS data were acquired at 9.4 T from the R6/2 mice and wild-type littermates at 4, 8, 12, and 15 weeks. Brain shrinkage was detectable in striatum, cortex, thalamus, and hypothalamus by 12 weeks. Metabolite changes in cortex paralleled and sometimes preceded those in striatum. The entire set of metabolite changes was compressed into principal components (PCs) using Partial Least Squares-Discriminant Analysis (PLS-DA) to increase the sensitivity for monitoring disease progression. In comparing the efficacy of volume and metabolite measurements, the cortical PC1 emerged as the most sensitive single biomarker, distinguishing R6/2 mice from littermates at all time points. Thus, neurochemical changes precede volume shrinkage and become potential biomarkers for HD mouse models.

PMID: 22044866 [PubMed - indexed for MEDLINE]

Early changes in white matter pathways of the sensorimotor cortex in premanifest Huntington's disease.

Hum Brain Mapp. 2012 Jan;33(1):203-12

Authors: Dumas EM, van den Bogaard SJ, Ruber ME, Reilman RR, Stout JC, Craufurd D, Hicks SL, Kennard C, Tabrizi SJ, van Buchem MA, van der Grond J, Roos RA

Abstract
OBJECTIVES: To investigate the function-structure relationship of white matter within different stages of Huntington's disease (HD) using diffusion tensor imaging (DTI).
EXPERIMENTAL DESIGN: From the TRACK-HD study, an early stage HD group and a premanifest gene carrier group (PMGC) were age-matched to two healthy control groups; all underwent 3-T MRI scanning of the brain. Region of interest (ROI) segmentation of the corpus callosum, caudate nucleus, thalamus, prefrontal cortex, and sensorimotor cortex was applied, and the apparent fiber pathways of these regions were analyzed. Functional measures of motor, oculomotor, cognition, and behavior were correlated to DTI measures. PRINCIPLE OBSERVATIONS: In PMGC versus controls, higher apparent diffusion coefficient (ADC) was seen in white matter pathways of the sensorimotor cortex (P < 0.01) and in the ROI of corpus callosum (P < 0.017). In early HD, fiber tract analysis showed higher ADC in pathways of the corpus callosum, thalamus, sensorimotor, and prefrontal region (P < 0.01). ROI analysis showed higher diffusivity in the corpus callosum and caudate nucleus (P < 0.017). Motor, oculomotor, cognition, and probability of onset within 2 and 5 years, correlated well with ADC measures of the corpus callosum (P < 0.01 - P < 0.005), sensorimotor (P < 0.01 - P < 0.005), and prefrontal region (P < 0.01).
CONCLUSIONS: Disturbances in the white matter connections of the sensorimotor cortex can be demonstrated not only in manifest HD but also in premanifest gene carriers. Connectivity measures are well related to clinical functioning. DTI measures can be regarded as a potential biomarker for HD, due to their ability to objectify changes in brain structures and their role within brain networks.

PMID: 21264990 [PubMed - indexed for MEDLINE]

Basal ganglia atrophy in prodromal Huntington's disease is detectable over one year using automated segmentation.

Mov Disord. 2011 Dec;26(14):2544-51

Authors: Majid DS, Aron AR, Thompson W, Sheldon S, Hamza S, Stoffers D, Holland D, Goldstein J, Corey-Bloom J, Dale AM

Abstract
Future clinical trials of neuroprotection in prodromal Huntington's (known as preHD) will require sensitive in vivo imaging biomarkers to track disease progression over the shortest period. Since basal ganglia atrophy is the most prominent structural characteristic of Huntington's pathology, systematic assessment of longitudinal subcortical atrophy holds great potential for future biomarker development. We studied 36 preHD and 22 age-matched controls using a novel method to quantify regional change from T(1) -weighted structural images acquired 1 year apart. We assessed cross-sectional volume differences and longitudinal volumetric change in 7 subcortical structures-the accumbens, amygdala, caudate, hippocampus, pallidum, putamen, and thalamus. At baseline, accumbens, caudate, pallidum, and putamen volumes were reduced in preHD versus controls (all P < .01). Longitudinally, atrophy was greater in preHD than controls in the caudate, pallidum, and putamen (all P < .01). Each structure showed a large between-group effect size, especially the pallidum where Cohen's d was 1.21. Using pallidal atrophy as a biomarker, we estimate that a hypothetical 1-year neuroprotection study would require only 35 preHD per arm to detect a 50% slowing in atrophy and only 138 preHD per arm to detect a 25% slowing in atrophy. The effect sizes calculated for preHD basal ganglia atrophy over 1 year are some of the largest reported to date. Consequently, this translates to strikingly small sample size estimates that will greatly facilitate any future neuroprotection study. This underscores the utility of this automatic image segmentation and longitudinal nonlinear registration method for upcoming studies of preHD and other neurodegenerative disorders.

PMID: 21932302 [PubMed - indexed for MEDLINE]

Automated structural imaging analysis detects premanifest Huntington's disease neurodegeneration within 1 year.

Mov Disord. 2011 Jul;26(8):1481-8

Authors: Majid DS, Stoffers D, Sheldon S, Hamza S, Thompson WK, Goldstein J, Corey-Bloom J, Aron AR

Abstract
Intense efforts are underway to evaluate neuroimaging measures as biomarkers for neurodegeneration in premanifest Huntington's disease (preHD). We used a completely automated longitudinal analysis method to compare structural scans in preHD individuals and controls. Using a 1-year longitudinal design, we analyzed T(1) -weighted structural scans in 35 preHD individuals and 22 age-matched controls. We used the SIENA (Structural Image Evaluation, using Normalization, of Atrophy) software tool to yield overall percentage brain volume change (PBVC) and voxel-level changes in atrophy. We calculated sample sizes for a hypothetical disease-modifying (neuroprotection) study. We found significantly greater yearly atrophy in preHD individuals versus controls (mean PBVC controls, -0.149%; preHD, -0.388%; P = .031, Cohen's d = .617). For a preHD subgroup closest to disease onset, yearly atrophy was more than 3 times that of controls (mean PBVC close-to-onset preHD, -0.510%; P = .019, Cohen's d = .920). This atrophy was evident at the voxel level in periventricular regions, consistent with well-established preHD basal ganglia atrophy. We estimated that a neuroprotection study using SIENA would only need 74 close-to-onset individuals in each arm (treatment vs placebo) to detect a 50% slowing in yearly atrophy with 80% power. Automated whole-brain analysis of structural MRI can reliably detect preHD disease progression in 1 year. These results were attained with a readily available imaging analysis tool, SIENA, which is observer independent, automated, and robust with respect to image quality, slice thickness, and different pulse sequences. This MRI biomarker approach could be used to evaluate neuroprotection in preHD.

PMID: 21484871 [PubMed - indexed for MEDLINE]

Potential endpoints for clinical trials in premanifest and early Huntington's disease in the TRACK-HD study: analysis of 24 month observational data.

Lancet Neurol. 2012 Jan;11(1):42-53

Authors: Tabrizi SJ, Reilmann R, Roos RA, Durr A, Leavitt B, Owen G, Jones R, Johnson H, Craufurd D, Hicks SL, Kennard C, Landwehrmeyer B, Stout JC, Borowsky B, Scahill RI, Frost C, Langbehn DR,

Abstract
BACKGROUND: TRACK-HD is a prospective observational biomarker study in premanifest and early Huntington's disease (HD). In this report we define a battery of potential outcome measures for therapeutic trials.
METHODS: We assessed longitudinal data collected at baseline, 12 months, and 24 months at sites in Leiden (Netherlands), London (UK), Paris (France), and Vancouver (Canada). Participants were individuals without HD but carrying the mutant HTT gene (ie, premanifest HD), patients with early HD, and healthy control individuals matched by age and sex to the combined HD groups. Data were collected with 3T MRI, clinical, cognitive, quantitative motor, oculomotor, and neuropsychiatric assessments. We estimated adjusted, between-group differences in rates of change in these measures and concomitant longitudinal effect sizes.
FINDINGS: Longitudinal data were available for 116 control individuals, 117 premanifest gene carriers, and 116 participants with early HD. Significantly greater progressive grey-matter, white-matter, whole-brain, and regional atrophy was recorded in the premanifest and early HD groups than in the control group. Effect sizes for atrophy rates between participants with early HD and controls were largest in the caudate (2·04, 95% CI 1·68 to 2·48) and white matter (1·70, 1·40 to 2·08). Functional, quantitative motor, and cognitive measures deteriorated to a greater extent in the early HD group than in controls, with the largest effect size in the symbol digit modality test (1·00, 0·67 to 1·27). In the early HD group, changes in structural imaging and various cognitive and quantitative motor scores were associated with worsening total motor score (TMS) and total functional capacity (TFC). In the premanifest group, despite significant declines in regional and overall brain volumes, few functional variables showed significant 24 month change compared with controls; TMS, emotion recognition, and speeded tapping were exceptions. Premanifest individuals with progression, predefined as an increase in TMS score of 5 points or more, any TFC decline, or a new diagnostic confidence score of 4, exhibited higher rates of brain atrophy and deterioration on some quantitative motor tasks compared with other premanifest participants.
INTERPRETATION: On the basis of longitudinal effect size, we recommend several objective outcome measures for clinical trials in participants with early HD. Hypothetical treatment effects defined by slower longitudinal changes in these measures would be detectable over a realistic timescale with practical sample sizes. The restricted 24 month cognitive or motor decline in the premanifest sample illustrates the greater challenge in trial design for this group.
FUNDING: CHDI/HighQ Foundation Inc.

PMID: 22137354 [PubMed - indexed for MEDLINE]

Extrastriatal dopamine D(2) receptor binding in Huntington's disease.

Hum Brain Mapp. 2011 Oct;32(10):1626-36

Authors: Esmaeilzadeh M, Farde L, Karlsson P, Varrone A, Halldin C, Waters S, Tedroff J

Abstract
Huntington's disease (HD) is a neurodegenerative disorder, primarily affecting medium spiny neurones in the striatum. The density of striatal dopamine D(2) receptors is reduced in HD but there is little known about this biomarker in brain regions outside the striatum. The primary objective of this study was to compare extrastriatal dopamine D(2) receptor binding, in age-matched control subjects and patients with HD. All subjects were examined using a high-resolution positron emission tomography system and the high-affinity dopamine D(2) receptor radioligand [(11) C]FLB 457. A ROI based analysis was used with an atrophy correction method. Dopamine D(2) receptor binding potential was reduced in the striatum of patients with HD. Unlike the striatum, dopamine D(2) receptor binding in thalamic and cortical subregions was not significantly different from that in control subjects. A partial least square regression analysis which included binding potential values from all investigated cortical and subcortical regions revealed a significant model separating patients from controls, conclusively dependent on differences in striatal binding of the radioligand. Some clinical assessments correlated with striatal dopamine D(2) receptor binding, including severity of chorea and cognitive test performance. Hence, the present study demonstrates that dopamine D(2) receptors extrinsic to the striatum are well preserved in early to mid stage patients with HD. This observation may have implication for the development of therapy for HD.

PMID: 20886576 [PubMed - indexed for MEDLINE]