Background: Huntington's disease (HD) is a neurodegenerative disease with cognitive, motor and psychiatric symptoms. A toxic accumulation of misfolded mutant huntingtin protein (Htt) induces... Show moreBackground: Huntington's disease (HD) is a neurodegenerative disease with cognitive, motor and psychiatric symptoms. A toxic accumulation of misfolded mutant huntingtin protein (Htt) induces mitochondrial dysfunction, leading to a bioenergetic insufficiency in neuronal and muscle cells. Improving mitochondrial function has been proposed as an opportunity to treat HD, but it is not known how mitochondrial function in different tissues relates.Objective: We explored associations between central and peripheral mitochondrial function in a group of mild to moderate staged HD patients.Methods: We used phosphorous magnetic resonance spectroscopy (31P-MRS) to measure mitochondrial function in vivo in the calf muscle (peripheral) and the bio-energetic state in the visual cortex (central). Mitochondrial function was also assessed ex vivo in circulating peripheral blood mononuclear cells (PBMCs). Clinical function was determined by the Unified Huntington's Disease Rating Scale (UHDRS) total motor score. Pearson correlation coefficients were computed to assess the correlation between the different variables.Results: We included 23 manifest HD patients for analysis. There was no significant correlation between central bio-energetics and peripheral mitochondrial function. Central mitochondrial function at rest correlated significantly to the UHDRS total motor score (R = -0.45 and -0.48), which increased in a subgroup with the largest number of CAG repeats.Discussion: We did not observe a correlation between peripheral and central mitochondrial function. Central, but not peripheral, mitochondrial function correlated to clinical function. Muscle mitochondrial function is a promising biomarker to evaluate disease-modifying compounds that improve mitochondrial function, but Huntington researchers should use central mitochondrial function to demonstrate proof-of-pharmacology of disease-modifying compounds. Show less
Coppen, E.M.; Jacobs, M.; Zwaan, K.F. van der; Middelkoop, H.A.M.; Roos, R.A.C. 2019
Objective: In Huntington's disease (HD), a hereditary neurodegenerative disorder, cognitive impairment in early disease stages mainly involves executive dysfunction. However, visual cognitive... Show moreObjective: In Huntington's disease (HD), a hereditary neurodegenerative disorder, cognitive impairment in early disease stages mainly involves executive dysfunction. However, visual cognitive deficits have additionally been reported and are of clinical relevance given their influence on daily life and overall cognitive performance. This study aimed to assess visual perceptual skills in HD gene carriers.Methods: Subtasks of the Visual Object and Space Perception battery and Groningen Intelligence Test were administered in 62 participants (18 healthy controls, 22 participants with a genetic confirmation of HD without symptoms, i.e., premanifest HD, and 22 participants with a genetic confirmation of HD with symptoms, i.e., manifest HD). Group differences in task performance were measured using analysis of covariance with and without correction for age. Receiver Operating Characteristics (ROC) analysis was performed to examine which task best discriminated between groups and cut-off scores were provided.Results: Manifest HD performed significantly worse compared to both controls and premanifest HD on all visual perceptional tasks. Premanifest HD did not differ in task performance from controls. Besides the Shape Detection, all tasks were robust in discriminating between groups. The Animal Silhouettes test was most accurate in discriminating manifest HD from premanifest HD (AUC = 0.90, SE = 0.048, p < .001).Conclusion: Visual perceptual deficits are present in early manifest HD, especially an impaired recognition of animals and objects from sketched silhouettes, and not in premanifest HD. This suggests that decline in visual processing only occurs in clinical disease stages. The visual cognitive battery, especially the Silhouettes tasks used in this study is sensitive in discriminating manifest HD from premanifest HD and controls. Show less
Huntington’s disease (HD) is a progressive autosomal dominant inherited neurodegenerative disorder.The primary aim of this thesis is to examine alterations in the cerebral cortex in HD gene... Show moreHuntington’s disease (HD) is a progressive autosomal dominant inherited neurodegenerative disorder.The primary aim of this thesis is to examine alterations in the cerebral cortex in HD gene carriers. Different image modalities and approaches will be used to extent the knowledge on both structural and functional cortical brain changes in early disease. Although striatal atrophy is more extensively present in HD, changes in the cerebral cortex can also be detected in the pre-symptomatic stage. Different methodological approaches used in our studies all showed a consistent pattern of cortical atrophy making volumetric MRI a reliable and effective tool to assess early in-vivo cortical brain changes, even in a rare neurodegenerative disorder such as HD. The influence of cortical changes on other clinical signs that occur in HD should not be overlooked. Our results demonstrate that volume loss and thinning of the cerebral cortex, especially the posterior brain regions, is detectable in early stages and contributes to the presence of specific motor signs and cognitive impairments. We believe that intervention trials could benefit from using cortical volumes as outcome measures, instead of using striatal volumes alone. Show less
Baake, V.; Coppen, E.M.; Duijn, E. van; Dumas, E.M.; Bogaard, S.J.A. van den; Scahill, R.I.; ... ; Track-HD Investigators 2018
Huntington's disease (HD) is an autosomal‐dominant inherited neurodegenerative disorder characterized by motor disturbances, psychiatric disturbances, and cognitive impairment. Visual cognitive... Show moreHuntington's disease (HD) is an autosomal‐dominant inherited neurodegenerative disorder characterized by motor disturbances, psychiatric disturbances, and cognitive impairment. Visual cognitive deficits and atrophy of the posterior cerebral cortex are additionally present in early disease stages. This study aimed to assess the extent of structural and functional brain alterations of the visual cortex in HD gene carriers using different neuroimaging modalities. Structural and functional magnetic resonance imaging data were acquired from 18 healthy controls, 21 premanifest, and 20 manifest HD gene carriers. Voxel‐based morphometry (VBM) analysis and cortical thickness measurements were performed to assess structural changes in the visual cortex. Brain function was measured by assessing neuronal connectivity changes in response to visual stimulation and at rest in visual resting‐state networks. Multiple linear regression analyses were performed to examine the relationship between visual cognitive function and structural imaging measures. Compared to controls, pronounced atrophy and decreased neuronal function at rest were present in associative visual cortices in manifest HD. The primary visual cortex did not show group differences in cortical thickness and in vascular activity after visual stimulation. Thinning of the associative visual cortex was related to worse visual perceptual function. Premanifest HD gene carriers did not show any differences in brain structure or function compared to controls. This study improves the knowledge on posterior brain changes in HD, as our findings suggest that the primary visual cortex remains preserved, both structurally and functionally, while atrophy of associative visual cortices is present in early HD and linked to clinical visual deficits. Show less
