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- Rauchmann, Boris Stephan, et al.
(författare)
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The impact of endurance training and table soccer on brain metabolites in schizophrenia
- 2020
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Ingår i: Brain Imaging and Behavior. - : Springer Science and Business Media LLC. - 1931-7557 .- 1931-7565. ; 14:2, s. 515-526
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Tidskriftsartikel (refereegranskat)abstract
- Higher glutamate and glutamine (together: Glx) and lower N-acetyl-aspartate (NAA) levels were reported in schizophrenia. Endurance training normalizes NAA in the hippocampus, but its effects on other metabolites in the brain and the relationship of metabolites to clinical symptoms remain unknown. For 12 weeks, 20 schizophrenia inpatients (14 men, 6 women) and 23 healthy controls (16 men, 7 women) performed endurance training and a control group of 21 schizophrenia inpatients (15 men, 6 women) played table soccer. A computer-assisted cognitive performance training program was introduced after 6 weeks. We assessed cognitive performance, psychopathological symptoms, and everyday functioning at baseline and after 6 and 12 weeks and performed single voxel magnetic resonance spectroscopy of the hippocampus, left dorsolateral prefrontal cortex (DLPFC), and thalamus. We quantified NAA, Glx, total creatine (tCr), calculated NAA/tCr and Glx/tCr and correlated these ratios with physical fitness, clinical and neurocognitive scores, and everyday functioning. At baseline, in both schizophrenia groups NAA/tCr was lower in the left DLPFC and left hippocampus and Glx/tCr was lower in the hippocampus than in the healthy controls. After 6 weeks, NAA/tCr increased in the left DLPFC in both schizophrenia groups. Brain metabolites did not change significantly in the hippocampus or thalamus, but the correlation between NAA/tCr and Glx/tCr normalized in the left DLPFC. Global Assessment of Functioning improvements correlated with NAA/tCr changes in the left DLPFC. In our study, endurance training and table soccer induced normalization of brain metabolite ratios in the brain circuitry associated with neuronal and synaptic elements, including metabolites of the glutamatergic system.
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| 2. |
- Baumeister, Hannah, et al.
(författare)
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A generalizable data-driven model of atrophy heterogeneity and progression in memory clinic settings
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Ingår i: Brain : a journal of neurology. - 1460-2156. ; 147:7, s. 2400-2413
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Tidskriftsartikel (refereegranskat)abstract
- Memory clinic patients are a heterogeneous population representing various aetiologies of pathological aging. It is unknown if divergent spatiotemporal progression patterns of brain atrophy, as previously described in Alzheimer's disease (AD) patients, are prevalent and clinically meaningful in this group of older adults. To uncover distinct atrophy subtypes, we applied the Subtype and Stage Inference (SuStaIn) algorithm to baseline structural MRI data from 813 participants enrolled in the DELCODE cohort (mean ± SD age = 70.67 ± 6.07 years, 52% females). Participants were cognitively unimpaired (CU; n = 285) or fulfilled diagnostic criteria for subjective cognitive decline (SCD; n = 342), mild cognitive impairment (MCI; n = 118), or dementia of the Alzheimer's type (n = 68). Atrophy subtypes were compared in baseline demographics, fluid AD biomarker levels, the Preclinical Alzheimer Cognitive Composite (PACC-5), as well as episodic memory and executive functioning. PACC-5 trajectories over up to 240 weeks were examined. To test if baseline atrophy subtype and stage predicted clinical trajectories before manifest cognitive impairment, we analysed PACC-5 trajectories and MCI conversion rates of CU and SCD participants. Limbic-predominant and hippocampal-sparing atrophy subtypes were identified. Limbic-predominant atrophy first affected the medial temporal lobes, followed by further temporal and, finally, the remaining cortical regions. At baseline, this subtype was related to older age, more pathological AD biomarker levels, APOE ε4 carriership, and an amnestic cognitive impairment. Hippocampal-sparing atrophy initially occurred outside the temporal lobe with the medial temporal lobe spared up to advanced atrophy stages. This atrophy pattern also affected individuals with positive AD biomarkers and was associated with more generalised cognitive impairment. Limbic-predominant atrophy, in all and in only unimpaired participants, was linked to more negative longitudinal PACC-5 slopes than observed in participants without or with hippocampal-sparing atrophy and increased the risk of MCI conversion. SuStaIn modelling was repeated in a sample from the Swedish BioFINDER-2 cohort. Highly similar atrophy progression patterns and associated cognitive profiles were identified. Cross-cohort model generalizability, both on the subject and group level, were excellent, indicating reliable performance in previously unseen data. The proposed model is a promising tool for capturing heterogeneity among older adults at early at-risk states for AD in applied settings. The implementation of atrophy subtype- and stage-specific end-points may increase the statistical power of pharmacological trials targeting early AD.
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| 4. |
- Dechent, Peter, et al.
(författare)
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Basal cerebral blood volume during the poststimulation undershoot in BOLD MRI of the human brain
- 2011
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 1559-7016 .- 0271-678X. ; 31:1, s. 82-89
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Tidskriftsartikel (refereegranskat)abstract
- One of the characteristics of the blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) response to functional challenges of the brain is the poststimulation undershoot, which has been suggested to originate from a delayed recovery of either cerebral blood volume (CBV) or cerebral metabolic rate of oxygen to baseline. Using bolus-tracking MRI in humans, we recently showed that relative CBV rapidly normalizes after the end of stimulation. As this observation contradicts at least part of the blood-pool contrast agent studies performed in animals, we reinvestigated the CBV contribution by dynamic T1-weighted three-dimensional MRI (8 seconds temporal resolution) and Vasovist at 3 T (12 subjects). Initially, we determined the time constants of individual BOLD responses. After injection of Vasovist, CBV-related T1-weighted signal changes revealed a signal increase during visual stimulation (1.7%±0.4%), but no change relative to baseline in the poststimulation phase (0.2%±0.3%). This finding renders the specific nature of the contrast agent unlikely to be responsible for the discrepancy between human and animal studies. With the assumption of normalized cerebral blood flow after stimulus cessation, a normalized CBV lends support to the idea that the BOLD MRI undershoot reflects a prolonged elevation of oxidative metabolism.
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| 8. |
- Dreha-Kulaczewski, Steffi, et al.
(författare)
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Folate receptor α deficiency : Myelin‐sensitive MRI as a reliable biomarker to monitor the efficacy and long‐term outcome of a new therapeutic approach
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Ingår i: Journal of Inherited Metabolic Disease. - 0141-8955. ; , s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral folate transport deficiency, caused by a genetic defect in folate recep-torα, is a devastating neurometabolic disorder that, if untreated, leads to epi-leptic encephalopathy, psychomotor decline and hypomyelination. Currently,there are limited data on effective dosage and duration of treatment, thoughearly diagnosis and therapy with folinic acid appears critical. The aim of thislong-term study was to identify new therapeutic approaches and novel bio-markers for assessing efficacy, focusing on myelin-sensitive MRI. Clinical, bio-chemical, structural and quantitative MRI parameters of seven patients withgenetically confirmed folate receptorαdeficiency were acquired over 13 years.Multimodal MRI approaches comprised MR-spectroscopy (MRS), magnetiza-tion transfer (MTI) and diffusion tensor imaging (DTI) sequences. Patientsstarted oral treatment immediately following diagnosis or in an interval of upto 2.5 years. Escalation to intravenous and intrathecal administration was per-formed in the absence of effects. Five patients improved, one with a presymp-tomatic start of therapy remained symptom-free, and one with inconsistenttreatment deteriorated. While CSF 5-methyltetrahydrofolate and MRS parame-ters normalized immediately after therapy initiation, myelin-sensitive MTI andDTI measures correlated with gradual clinical improvement and ongoing mye-lination under therapy. Early initiation of treatment at sufficient doses, consid-ering early intrathecal applications, is critical for favorable outcome. Themajority of patients showed clinical improvements that correlated best withMTI parameters, allowing individualized monitoring of myelination recovery.Presymptomatic therapy seems to ensure normal development and warrantsnewborn screening. Furthermore, the quantitative parameters of myelin-sensitive MRI for therapy assessments can now be used for hypomyelinationdisorders in general.
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