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van Steenis EM, Huijbregts SCJ, Vliet DDV, Heiner-Fokkema MR, Rennings AJM, Baron P, Sijens PE, van Spronsen FJ. Inter-individuality in the transport and effect of phenylalanine in the brain: A double case report of two 'unusual' phenylketonuria patients. Mol Genet Metab 2025; 145:109085. [PMID: 40154188 DOI: 10.1016/j.ymgme.2025.109085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2024] [Revised: 03/07/2025] [Accepted: 03/07/2025] [Indexed: 04/01/2025]
Abstract
BACKGROUND In phenylketonuria, high plasma phenylalanine concentrations have been associated with cognitive impairments. Still, there are reports of patients with high plasma phenylalanine without apparent cognitive dysfunction. This suggests inter-individual differences in the extent and nature of the negative effects of elevated plasma phenylalanine. This work reports two 'unusual' female patients, of 56 and 57 years old, who were late-treated, with a diagnosis at 8 and 2 years old, but show an estimated IQ of 105. Insight into the functioning of these 'unusual' patients aids our understanding of the pathology behind phenylketonuria. METHODS Neurocognitive functioning was evaluated with the Amsterdam Neuropsychological Tasks, comparing measures of executive functions (EF; sustained attention, cognitive flexibility and working memory) and emotion recognition with 25 adult early-treated phenylketonuria patients (ET-PKU; mean 35.2 years, SD 3.3) from the COBESO-PKU database. Brain phenylalanine levels were determined with magnetic resonance spectroscopy, and compared to those of 'usual' phenylketonuria patients reported in literature. RESULTS On the EF, performance was only slightly decreased (#A), or similar (#B) compared to ET-PKU, while plasma phenylalanine concentrations were 883 and 1181 μmol/L (mean ET-PKU: 687.5 μmol/L, SD 329.5). The brain-to-blood phenylalanine ratio of patient #A (0.20) was close to the expected range for 'usual' phenylketonuria patients (median 0.28, IQR 0.11), while #B showed a lower ratio (0.07). DISCUSSION Both #A and #B have a far better outcome than expected based on their late diagnosis and dietary adherence afterwards. Although both patients had no severe neurocognitive dysfunction, slight deficits on EF and emotion regulation compared to ET-PKU cannot be ruled out. This underlines the importance of individually-tailored treatment in these patients. Interestingly, inter-individuality in the brain-to-blood phenylalanine ratio could explain the 'unusually' good outcome of patient #B, but not in patient #A. Suggesting that altered phenylalanine transport between blood and brain can explain some, but not all 'unusual' cases. Other explanations are needed and may relate to inter-individual vulnerability of the brain to elevated phenylalanine.
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Affiliation(s)
- E M van Steenis
- University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Division of Metabolic Diseases, Groningen, the Netherlands
| | - S C J Huijbregts
- Leiden University, Department of Education and Child Studies, Leiden, the Netherlands
| | - D Draaisma-van Vliet
- University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Division of Metabolic Diseases, Groningen, the Netherlands
| | - M R Heiner-Fokkema
- University of Groningen, University Medical Center Groningen, Laboratory of Metabolic Diseases, Groningen, the Netherlands
| | - A J M Rennings
- Radboud University Medical Center Nijmegen, Department of Internal Medicine, Nijmegen, the Netherlands
| | - P Baron
- University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, the Netherlands
| | - P E Sijens
- University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, the Netherlands
| | - F J van Spronsen
- University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Division of Metabolic Diseases, Groningen, the Netherlands.
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Parsaei M, Barahman G, Roumiani PH, Ranjbar E, Ansari S, Najafi A, Karimi H, Aarabi MH, Moghaddam HS. White matter correlates of cognition: A diffusion magnetic resonance imaging study. Behav Brain Res 2025; 476:115222. [PMID: 39216828 DOI: 10.1016/j.bbr.2024.115222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 08/23/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
BACKGROUND Our comprehension of the interplay of cognition and the brain remains constrained. While functional imaging studies have identified cognitive brain regions, structural correlates of cognitive functions remain underexplored. Advanced methods like Diffusion Magnetic Resonance Imaging (DMRI) facilitate the exploration of brain connectivity and White Matter (WM) tract microstructure. Therefore, we conducted connectometry method on DMRI data, to reveal WM tracts associated with cognition. METHODS 125 healthy participants from the National Institute of Mental Health Intramural Healthy Volunteer Dataset were recruited. Multiple regression analyses were conducted between DMRI-derived Quantitative Anisotropy (QA) values within WM tracts and scores of participants in Flanker Inhibitory Control and Attention Test (attention), Dimensional Change Card Sort (executive function), Picture Sequence Memory Test (episodic memory), and List Sorting Working Memory Test (working memory) tasks from National Institute of Health toolbox. The significance level was set at False Discovery Rate (FDR)<0.05. RESULTS We identified significant positive correlations between the QA of WM tracts within the left cerebellum and bilateral fornix with attention, executive functioning, and episodic memory (FDR=0.018, 0.0002, and 0.0002, respectively), and a negative correlation between QA of WM tracts within bilateral cerebellum with attention (FDR=0.028). Working memory demonstrated positive correlations with QA of left inferior longitudinal and left inferior fronto-occipital fasciculi (FDR=0.0009), while it showed a negative correlation with QA of right cerebellar tracts (FDR=0.0005). CONCLUSION Our results underscore the intricate link between cognitive performance and WM integrity in frontal, temporal, and cerebellar regions, offering insights into early detection and targeted interventions for cognitive disorders.
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Affiliation(s)
- Mohammadamin Parsaei
- Maternal, Fetal & Neonatal Research Center, Family Health Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Gelayol Barahman
- School of Medicine, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran
| | | | - Ehsan Ranjbar
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Sahar Ansari
- Psychosomatic Medicine Research Center, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Anahita Najafi
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hanie Karimi
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hadi Aarabi
- Department of Neuroscience, University of Padova, Padova, Italy; Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Hossein Sanjari Moghaddam
- Psychiatry and Psychology Research Center, Roozbeh Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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3
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Muri R, Reed MB, Maissen‐Abgottspon S, Kreis R, Hochuli M, Lanzenberger R, Trepp R, Everts R. Reversible white matter changes following a 4-week high phenylalanine exposure in adults with phenylketonuria. J Inherit Metab Dis 2025; 48:e12823. [PMID: 39604093 PMCID: PMC11670274 DOI: 10.1002/jimd.12823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2024] [Revised: 11/11/2024] [Accepted: 11/18/2024] [Indexed: 11/29/2024]
Abstract
Alterations in brain structure are frequently observed in adults with early-treated phenylketonuria (PKU) compared to healthy controls, with cerebral white matter (WM) being particularly affected. The extent to which temporary elevation of phenylalanine (Phe) levels impacts WM remains unclear. We conducted a double-blind, randomised, placebo-controlled crossover trial to investigate the effects of a 4-week high Phe exposure on cerebral WM and its relationship to cognitive performance and metabolic parameters in adults with PKU. In this study, 27 adults with early-treated classical PKU (aged 19-48 years) underwent diffusion tensor imaging (DTI) before and after the 4-week Phe and placebo interventions. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were analysed using tract-based spatial statistics. Neuropsychological examinations at each timepoint evaluated executive functions and attention. Additionally, brain Phe levels were measured using MR spectroscopy, and blood levels of Phe, tyrosine, and tryptophan were assessed after an overnight fast. Following the Phe period, significant decreases in AD, MD, and RD were observed compared to the placebo period, particularly in the posterior corona radiata and optic radiation. Notably, these WM changes were reversible in patients who first received Phe (n = 13). Cognitive performance and metabolic parameters were not significantly related to DTI scalars after the Phe period. In conlcusion, a 4-week Phe elevation induced reversible microstructural alterations in cerebral WM. Further investigation is necessary to determine the clinical implication of these changes.
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Affiliation(s)
- Raphaela Muri
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, InselspitalBern University Hospital and University of BernBernSwitzerland
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, InselspitalBern University Hospital and University of BernBernSwitzerland
- Translational Imaging Center (TIC)Swiss Institute for Translational and Entrepreneurial MedicineBernSwitzerland
| | - Murray Bruce Reed
- Department of Psychiatry and PsychotherapyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH)Medical University of ViennaViennaAustria
| | - Stephanie Maissen‐Abgottspon
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, InselspitalBern University Hospital and University of BernBernSwitzerland
- Translational Imaging Center (TIC)Swiss Institute for Translational and Entrepreneurial MedicineBernSwitzerland
| | - Roland Kreis
- Translational Imaging Center (TIC)Swiss Institute for Translational and Entrepreneurial MedicineBernSwitzerland
- Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, InselspitalBern University Hospital and University of BernBernSwitzerland
| | - Michel Hochuli
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, InselspitalBern University Hospital and University of BernBernSwitzerland
| | - Rupert Lanzenberger
- Department of Psychiatry and PsychotherapyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental Health (C3NMH)Medical University of ViennaViennaAustria
| | - Roman Trepp
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, InselspitalBern University Hospital and University of BernBernSwitzerland
| | - Regula Everts
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, InselspitalBern University Hospital and University of BernBernSwitzerland
- Translational Imaging Center (TIC)Swiss Institute for Translational and Entrepreneurial MedicineBernSwitzerland
- Division of Neuropaediatrics, Development and Rehabilitation, Department of Paediatrics, InselspitalBern University Hospital and University of BernBernSwitzerland
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Thomas L, Aitkenhead L, Stepien KM, Woodall A, Macdonald A, Romani C. Cognition and wellbeing in middle-aged early treated people with phenylketonuria: Preliminary results and methodological lessons. Mol Genet Metab Rep 2024; 41:101160. [PMID: 39639994 PMCID: PMC11617784 DOI: 10.1016/j.ymgmr.2024.101160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 09/22/2024] [Accepted: 11/08/2024] [Indexed: 12/07/2024] Open
Abstract
The first cohort of early-treated adults with phenylketonuria (PKU) is reaching middle-age and moving towards old age. We do not know if and how the effects of an aging brain may interact with the effect of PKU. This study compared wellbeing and cognition in 19 middle-aged adults with PKU (age 40+ mean = 45.8) and in a younger adult PKU group (age 18-36 mean = 26.7). The middle-aged PKU group demonstrated more anxiety and depression, and more negative effects of the COVID-19 pandemic, compared to age-matched controls. They also demonstrated a steep deterioration of quality of life compared to younger adults with PKU. These last results confounded age with the effects of the pandemic, since only the older participants were tested during the COVID-19 pandemic, but taken together, results consistently point to AwPKU being less resilient to age and other life stressors affecting wellbeing. Regarding cognition, the older PKU group demonstrated significantly worse performance than the younger group, and within the middle-age groups, the effect of age was stronger in the PKU group than in the control, even though this was not statistically significant. In contrast, size of impairment relative to an age-matched control group was numerically smaller in older, middle-age PKU group. We discuss possible methodological confounders related to this last result. Our study points to the challenges of using cross-sectional results to track performance across the lifespan and to the need to acquire more corroborating evidence before concluding there is no accelerating brain aging in PKU.
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Affiliation(s)
| | | | | | - Alison Woodall
- Salford Royal Organization, Northern Care Alliance NHS Foundation Trust, UK
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Muri R, Rummel C, McKinley R, Rebsamen M, Maissen-Abgottspon S, Kreis R, Radojewski P, Pospieszny K, Hochuli M, Wiest R, Trepp R, Everts R. Transient brain structure changes after high phenylalanine exposure in adults with phenylketonuria. Brain 2024; 147:3863-3873. [PMID: 38723047 PMCID: PMC11604053 DOI: 10.1093/brain/awae139] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/19/2024] [Accepted: 05/08/2024] [Indexed: 11/05/2024] Open
Abstract
Phenylketonuria is a rare metabolic disease resulting from a deficiency of the enzyme phenylalanine hydroxylase. Recent cross-sectional evidence suggests that early-treated adults with phenylketonuria exhibit alterations in cortical grey matter compared to healthy peers. However, the effects of high phenylalanine exposure on brain structure in adulthood need to be further elucidated. In this double-blind, randomized, placebo-controlled crossover trial, we investigated the impact of a 4-week high phenylalanine exposure on the brain structure and its relationship to cognitive performance and metabolic parameters in early-treated adults with phenylketonuria. Twenty-eight adult patients with early-treated classical phenylketonuria (19-48 years) underwent magnetic resonance imaging before and after the 4-week phenylalanine and placebo interventions (four time points). Structural T1-weighted images were preprocessed and evaluated using Direct Cortical Thickness Estimation using Deep Learning-based Anatomy Segmentation and Cortex Parcellation (DL+DiReCT), a deep-learning-based tool for brain morphometric analysis. Cortical thickness, white matter volume and ventricular volume were compared between the phenylalanine and placebo periods. Brain phenylalanine levels were measured using 1H spectroscopy. Blood levels of phenylalanine, tyrosine, and tryptophan were assessed at each of the four time points, along with performance in executive functions and attention. Blood phenylalanine levels were significantly higher after the phenylalanine period (1441 µmol/l) than after the placebo period (873 µmol/l, P < 0.001). Morphometric analyses revealed a statistically significant decrease in cortical thickness in 17 of 60 brain regions after the phenylalanine period compared to placebo. The largest decreases were observed in the right pars orbitalis (point estimate = -0.095 mm, P < 0.001) and the left lingual gyrus (point estimate = -0.070 mm, P < 0.001). Bilateral white matter and ventricular volumes were significantly increased after the phenylalanine period. However, the structural alterations in the phenylalanine-placebo group returned to baseline measures following the washout and placebo period. Additionally, elevated blood and brain phenylalanine levels were related to increased bilateral white matter volume (rs = 0.43 to 0.51, P ≤ 0.036) and decreased cortical thickness [rs = -0.62 to -0.39, not surviving false discovery rate (FDR) correction] after the phenylalanine and placebo periods. Moreover, decreased cortical thickness was correlated with worse cognitive performance after both periods (rs = -0.54 to -0.40, not surviving FDR correction). These findings provide evidence that a 4-week high phenylalanine exposure in adults with phenylketonuria results in transient reductions of the cortical grey matter and increases in white matter volume. Further research is needed to determine the potential long-term impact of high phenylalanine levels on brain structure and function in adults with phenylketonuria.
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Affiliation(s)
- Raphaela Muri
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, 3010 Bern, Switzerland
| | - Christian Rummel
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
| | - Richard McKinley
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
| | - Michael Rebsamen
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
| | - Stephanie Maissen-Abgottspon
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, 3010 Bern, Switzerland
| | - Roland Kreis
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, 3010 Bern, Switzerland
- Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
| | - Piotr Radojewski
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, 3010 Bern, Switzerland
| | - Katarzyna Pospieszny
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
| | - Michel Hochuli
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
| | - Roland Wiest
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, 3010 Bern, Switzerland
| | - Roman Trepp
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
| | - Regula Everts
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, 3010 Bern, Switzerland
- Division of Neuropaediatrics, Development and Rehabilitation, Department of Paediatrics, Inselspital, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
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Tomm A, Thiele AG, Rohde C, Kirmse S, Kiess W, Beblo S. Executive functions & metabolic control in phenylketonuria (PKU) and mild hyperphenylalaninemia (mHPA). Mol Genet Metab 2024; 143:108544. [PMID: 39059271 DOI: 10.1016/j.ymgme.2024.108544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/18/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024]
Abstract
BACKGROUND Due to newborn screening and early treatment, patients with phenylketonuria (PKU) and mild hyperphenylalaninemia (mHPA) develop largely normal, in terms of IQ testing and academic attainment. However, the impact of metabolic control in various stages of development on more complex cognitive abilities, i.e. executive functions (EF), is still unclear. METHODS EFs were tested in 28 patients with PKU/mHPA, aged 8-17 years, identified by newborn screening and continuously treated. The relation to current (testing day & past 10 phenylalanine (Phe) values) and long-term metabolic control (age periods: childhood <6, 6-10, adolescence >10 years, lifetime Phe) was analyzed. RESULTS EFs were in the lower normative range (IQR of T-values: 47.35-51.00). Patients reaction time was significantly slower than the population mean (divided attention/TAP: median 40, p < 0.01). Both, long-term and current metabolic control correlated with performance in EF tests: Higher current Phe impaired reaction times (Go/No-Go, r = -0.387; working memory, r = -0.425; p < 0.05) and performance in planning ability (ToL r = -0.465, p < 0.01). Higher long-term Phe values both in childhood and adolescence mainly affected attention (omissions/TAP r = -0.357 and - 0.490, respectively, both p < 0.05) as well as planning ability (ToL r = -0.422 and - 0.387, adolescence and lifetime, p < 0.05). CONCLUSION Current and long-term metabolic control in PKU/mHPA, including the adolescent period, influence EFs, especially affecting reaction time and planning abilities. This should be taken into account in patient counselling.
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Affiliation(s)
- Anne Tomm
- Center for Pediatric Research Leipzig, Department of Women and Child Health, Hospital for Children and Adolescents, University Hospital, Germany.
| | - Alena G Thiele
- Center for Pediatric Research Leipzig, Department of Women and Child Health, Hospital for Children and Adolescents, University Hospital, Germany.
| | - Carmen Rohde
- Center for Pediatric Research Leipzig, Department of Women and Child Health, Hospital for Children and Adolescents, University Hospital, Germany.
| | - Stefanie Kirmse
- Center for Pediatric Research Leipzig, Department of Women and Child Health, Hospital for Children and Adolescents, University Hospital, Germany.
| | - Wieland Kiess
- Center for Pediatric Research Leipzig, Department of Women and Child Health, Hospital for Children and Adolescents, University Hospital, Germany.
| | - Skadi Beblo
- Center for Pediatric Research Leipzig, Department of Women and Child Health, Hospital for Children and Adolescents, University Hospital, Germany; Leipzig University Center for Rare Diseases, Philipp-Rosenthal-Str. 55, 04103 Leipzig, Germany.
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Maissen-Abgottspon S, Steiner L, Muri R, Wijesinghe D, Jann K, Morishima Y, Hochuli M, Kreis R, Trepp R, Everts R. Effect of a four-week oral Phe administration on neural activation and cerebral blood flow in adults with early-treated phenylketonuria. Neuroimage Clin 2024; 43:103654. [PMID: 39146838 PMCID: PMC11367652 DOI: 10.1016/j.nicl.2024.103654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 08/06/2024] [Accepted: 08/06/2024] [Indexed: 08/17/2024]
Abstract
BACKGROUND Phenylketonuria (PKU) is a rare inborn error of metabolism characterized by impaired catabolism of the amino acid phenylalanine (Phe) into tyrosine. Cross-sectional studies suggest slight alterations in cognitive performance and neural activation in adults with early-treated PKU. The influence of high Phe levels on brain function in adulthood, however, remains insufficiently studied. Therefore, we aimed to explore the effect of a four-week period of oral Phe administration - simulating a controlled discontinuation of Phe restriction and raising Phe to an off-diet scenario - on working memory-related neural activation and cerebral blood flow (CBF). METHODS We conducted a randomized, placebo-controlled, double-blind, crossover, non-inferiority trial to assess the effect of a high Phe load on working memory-related neural activation and CBF in early-treated adults with classical PKU. Twenty-seven patients with early-treated classical PKU were included and underwent functional magnetic resonance imaging (fMRI) of the working memory network and arterial spin labeling (ASL) MRI to assess CBF before and after a four-week intervention with Phe and placebo. At each of the four study visits, fMRI working memory task performance (reaction time and accuracy) and plasma Phe, tyrosine, and tryptophan levels were obtained. Additionally, cerebral Phe was determined by 1H-MR spectroscopy. RESULTS Plasma Phe and cerebral Phe were significantly increased after the Phe intervention. However, no significant effect of Phe compared to placebo was found on neural activation and CBF. Regarding fMRI task performance, a significant impact of the Phe intervention on 1-back reaction time was observed with slower reaction times following the Phe intervention, whereas 3-back reaction time and accuracy did not differ following the Phe intervention compared to the placebo intervention. CONCLUSION Results from this present trial simulating a four-week discontinuation of the Phe-restricted diet showed that a high Phe load did not uniformly affect neural markers and cognition in a statistically significant manner. These results further contribute to the discussion on safe Phe levels during adulthood and suggest that a four-week discontinuation of Phe-restricted diet does not demonstrate significant changes in brain function.
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Affiliation(s)
- Stephanie Maissen-Abgottspon
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Leonie Steiner
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Raphaela Muri
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Support Center for Advanced Neuroimaging (SCAN), University Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Dilmini Wijesinghe
- Laboratory of Functional MRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, USA
| | - Kay Jann
- Laboratory of Functional MRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, USA
| | - Yosuke Morishima
- Translational Research Center, University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland
| | - Michel Hochuli
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Roland Kreis
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland; Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Roman Trepp
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Regula Everts
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland; Neuropediatrics, Development and Rehabilitation, University Children's Hospital, Inselspital, Bern, Switzerland.
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Hanusch B, Falkenstein M, Volkenstein S, Dazert S, Lücke T, Sinningen K. No Impairment in Bone Turnover or Executive Functions in Well-Treated Preschoolers with Phenylketonuria-A Pilot Study. Nutrients 2024; 16:2072. [PMID: 38999818 PMCID: PMC11243048 DOI: 10.3390/nu16132072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/20/2024] [Accepted: 06/25/2024] [Indexed: 07/14/2024] Open
Abstract
Patients with phenylketonuria (PKU) present signs of impaired executive functioning and bone health in adolescence and adulthood, depending in part on the success of therapy in childhood. Therefore, nine children with well-treated PKU (4-7 years old, 22.2% ♀, seven with a full set of data, two included into partial analysis) and 18 age-, gender- and season-matched controls were analyzed for differences in executive functioning and bone parameters in plasma. Plasma was analyzed with commercially available kits. Cognitive performance in tonic alertness, visuo-spatial working memory, inhibitory control and task switching was assessed by a task battery presented on a touch screen. Regarding cognition, only the performance in incongruent conditions in inhibitory control was significantly better in children with PKU than in controls. No further differences in cognitive tests were detected. Furthermore, no significant difference in the bone turnover markers osteocalcin, undercarboxylated osteocalcin and CTX were detected between children with PKU and controls, while children with PKU had a significantly higher vitamin D concentration (69.44 ± 12.83 nmol/L vs. 41.87 ± 15.99 nmol/L, p < 0.001) and trended towards lower parathyroid hormone concentrations than controls (48.27 ± 15.16 pg/mL vs. 70.61 ± 30.53 pg/mL, p = 0.066). In this small group of well-treated preschoolers with PKU, no impairments in cognitive performance and bone turnover were observed, while vitamin D supplementation of amino acid supplements seems to be sufficient to achieve good vitamin D status.
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Affiliation(s)
- Beatrice Hanusch
- Research Department of Child Nutrition, University Hospital of Pediatrics and Adolescent Medicine, St. Josef-Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | | | - Stefan Volkenstein
- Department of Otorhinolaryngology, Head and Neck Surgery, Johannes Wesling Klinikum Minden, Ruhr-University Bochum, 32429 Minden, Germany
| | - Stefan Dazert
- Department of Otorhinolaryngology, Head and Neck Surgery, St. Elisabeth-Hospital Bochum, Ruhr-University Bochum, 44787 Bochum, Germany
| | - Thomas Lücke
- Research Department of Child Nutrition, University Hospital of Pediatrics and Adolescent Medicine, St. Josef-Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Kathrin Sinningen
- Research Department of Child Nutrition, University Hospital of Pediatrics and Adolescent Medicine, St. Josef-Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
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9
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Pardo J, Capdevila-Lacasa C, Segura B, Pané A, Montserrat C, de Talló Forga-Visa M, Moreno PJ, Garrabou G, Grau-Junyent JM, Junqué C. Volumetric brain reductions in adult patients with phenylketonuria and their relationship with blood phenylalanine levels. J Neurodev Disord 2024; 16:33. [PMID: 38907189 PMCID: PMC11193301 DOI: 10.1186/s11689-024-09553-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 06/17/2024] [Indexed: 06/23/2024] Open
Abstract
BACKGROUND Continued dietary treatment since early diagnosis through newborn screening programs usually prevents brain-related complications in phenylketonuria (PKU). However, subtle neurocognitive and brain alterations may be observed in some adult patients despite early treatment. Nevertheless, neuropsychological and neuroimaging studies in the field remain scarce. OBJECTIVES This work aimed to determine possible neuropsychological and structural brain alterations in treated adult patients with PKU. METHODS Thirty-five patients with PKU and 22 healthy controls (HC) underwent neuropsychological assessment and T1-weighted magnetic resonance imaging on a 3 T scanner. FreeSurfer (v.7.1) was used to obtain volumetric measures and SPSS (v27.0.1.0) was used to analyze sociodemographic, neuropsychological, volumetric, and clinical data (p < 0.05). RESULTS Adult patients with PKU showed significantly lower performance than HC in Full Scale IQ (t = 2.67; p = .010) from the WAIS-IV. The PKU group also showed significantly lower volumes than HC in the pallidum (U = 224.000; p = .008), hippocampus (U = 243.000; p = .020), amygdala (U = 200.000; p = .002), and brainstem (t = 3.17; p = .006) as well as in total cerebral white matter volume (U = 175.000; p = .001). Blood phenylalanine (Phe) levels in PKU patients were negatively correlated with the pallidum (r = -0.417; p = .013) and brainstem (r = -0.455, p = .006) volumes. CONCLUSIONS Adult patients with early-treated PKU showed significantly lower global intelligence than HC. Moreover, these patients showed reduced global white matter volume as well as reductions in the volume of several subcortical grey matter structures, which might be related to the existence of underlying neurodevelopmental alterations. Higher blood Phe levels were also negatively correlated with pallidum and brainstem, suggesting a higher vulnerability of these structures to Phe toxicity.
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Affiliation(s)
- Jèssica Pardo
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
| | - Clara Capdevila-Lacasa
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
| | - Bàrbara Segura
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain.
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain.
- Biomedical Research Networking Center On Neurodegenerative Diseases (CIBERNED: CB06/05/0018-ISCIII), Barcelona, Catalonia, Spain.
| | - Adriana Pané
- Biomedical Research Networking Center on Physiopathology of Obesity and Nutrition (CIBEROBN), Barcelona, Catalonia, Spain
- Endocrinology and Nutrition Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| | - Cristina Montserrat
- Endocrinology and Nutrition Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| | - Maria de Talló Forga-Visa
- Endocrinology and Nutrition Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| | - Pedro J Moreno
- Internal Medicine Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
- Inherited Metabolic Diseases and Muscle Disorders Research, Centre de Recerca Biomèdica CELLEX - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Catalonia, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Barcelona, Catalonia, Spain
| | - Glòria Garrabou
- Internal Medicine Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
- Inherited Metabolic Diseases and Muscle Disorders Research, Centre de Recerca Biomèdica CELLEX - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Catalonia, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Barcelona, Catalonia, Spain
| | - Josep M Grau-Junyent
- Internal Medicine Department, Adult Inherited Metabolic Disorders Unit (UECMA), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
- Inherited Metabolic Diseases and Muscle Disorders Research, Centre de Recerca Biomèdica CELLEX - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Catalonia, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Barcelona, Catalonia, Spain
| | - Carme Junqué
- Institute of Neurosciences, Medical Psychology Unit, Department of Medicine, University of Barcelona, C/ Casanova 143, Barcelona, Catalonia, 08036, Spain
- Fundació de Recerca Clínic Barcelona-Institut d'Investigacions Biomèdiques August Pi I Sunyer (FRCB-IDIBAPS), Barcelona, Catalonia, Spain
- Biomedical Research Networking Center On Neurodegenerative Diseases (CIBERNED: CB06/05/0018-ISCIII), Barcelona, Catalonia, Spain
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10
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Trefz F, Frauendienst-Egger G, Dienel G, Cannet C, Schmidt-Mader B, Haas D, Blau N, Himmelreich N, Spraul M, Freisinger P, Dobrowolski S, Berg D, Pilotto A. Does hyperphenylalaninemia induce brain glucose hypometabolism? Cerebral spinal fluid findings in treated adult phenylketonuric patients. Mol Genet Metab 2024; 142:108464. [PMID: 38537426 DOI: 10.1016/j.ymgme.2024.108464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 05/08/2024]
Abstract
Despite numerous studies in human patients and animal models for phenylketonuria (PKU; OMIM#261600), the pathophysiology of PKU and the underlying causes of brain dysfunction and cognitive problems in PKU patients are not well understood. In this study, lumbar cerebral spinal fluid (CSF) was obtained immediately after blood sampling from early-treated adult PKU patients who had fasted overnight. Metabolite and amino acid concentrations in the CSF of PKU patients were compared with those of non-PKU controls. The CSF concentrations and CSF/plasma ratios for glucose and lactate were found to be below normal, similar to what has been reported for glucose transporter1 (GLUT1) deficiency patients who exhibit many of the same clinical symptoms as untreated PKU patients. CSF glucose and lactate levels were negatively correlated with CSF phenylalanine (Phe), while CSF glutamine and glutamate levels were positively correlated with CSF Phe levels. Plasma glucose levels were negatively correlated with plasma Phe concentrations in PKU subjects, which partly explains the reduced CSF glucose concentrations. Although brain glucose concentrations are unlikely to be low enough to impair brain glucose utilization, it is possible that the metabolism of Phe in the brain to produce phenyllactate, which can be transported across the blood-brain barrier to the blood, may consume glucose and/or lactate to generate the carbon backbone for glutamate. This glutamate is then converted to glutamine and carries the Phe-derived ammonia from the brain to the blood. While this mechanism remains to be tested, it may explain the correlations of CSF glutamine, glucose, and lactate concentrations with CSF Phe.
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Affiliation(s)
- Friedrich Trefz
- Heidelberg University, Medical Faculty of Heidelberg, Center for Child and Adolescent Medicine, Division of Child Neurology and Metabolic Medicine, Heidelberg, Germany.
| | | | - Gerald Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, United States; Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States
| | | | - Brigitte Schmidt-Mader
- Heidelberg University, Medical Faculty of Heidelberg, Center for Child and Adolescent Medicine, Division of Child Neurology and Metabolic Medicine, Heidelberg, Germany
| | - Dorothea Haas
- Heidelberg University, Medical Faculty of Heidelberg, Center for Child and Adolescent Medicine, Division of Child Neurology and Metabolic Medicine, Heidelberg, Germany
| | - Nenad Blau
- University Children's Hospital Zürich, Zürich, Switzerland
| | | | | | - Peter Freisinger
- Klinikum Reutlingen, Department of Pediatrics, Reutlingen, Germany
| | - Steven Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15224, United States
| | - Daniela Berg
- Department of Neurology, University Hospital of Schleswig-Holstein, Kiel, Germany
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11
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Steiner L, Muri R, Wijesinghe D, Jann K, Maissen-Abgottspon S, Radojewski P, Pospieszny K, Kreis R, Kiefer C, Hochuli M, Trepp R, Everts R. Cerebral blood flow and white matter alterations in adults with phenylketonuria. Neuroimage Clin 2023; 41:103550. [PMID: 38091797 PMCID: PMC10716784 DOI: 10.1016/j.nicl.2023.103550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/15/2023] [Accepted: 12/08/2023] [Indexed: 03/16/2024]
Abstract
BACKGROUND Phenylketonuria (PKU) represents a congenital metabolic defect that disrupts the process of converting phenylalanine (Phe) into tyrosine. Earlier investigations have revealed diminished cognitive performance and changes in brain structure and function (including the presence of white matter lesions) among individuals affected by PKU. However, there exists limited understanding regarding cerebral blood flow (CBF) and its potential associations with cognition, white matter lesions, and metabolic parameters in patients with PKU, which we therefore aimed to investigate in this study. METHOD Arterial spin labeling perfusion MRI was performed to measure CBF in 30 adults with early-treated classical PKU (median age 35.5 years) and 59 healthy controls (median age 30.0 years). For all participants, brain Phe levels were measured with 1H spectroscopy, and white matter lesions were rated by two neuroradiologists on T2 weighted images. White matter integrity was examined with diffusion tensor imaging (DTI). For patients only, concurrent plasma Phe levels were assessed after an overnight fasting period. Furthermore, past Phe levels were collected to estimate historical metabolic control. On the day of the MRI, each participant underwent a cognitive assessment measuring IQ and performance in executive functions, attention, and processing speed. RESULTS No significant group difference was observed in global CBF between patients and controls (F (1, 87) = 3.81, p = 0.054). Investigating CBF on the level of cerebral arterial territories, reduced CBF was observed in the left middle and posterior cerebral artery (MCA and PCA), with the most prominent reduction of CBF in the anterior subdivision of the MCA (F (1, 87) = 6.15, p = 0.015, surviving FDR correction). White matter lesions in patients were associated with cerebral blood flow reduction in the affected structure. Particularly, patients with lesions in the occipital lobe showed significant CBF reductions in the left PCA (U = 352, p = 0.013, surviving FDR correction). Additionally, axial diffusivity measured with DTI was positively associated with CBF in the ACA and PCA (surviving FDR correction). Cerebral blood flow did not correlate with cognitive performance or metabolic parameters. CONCLUSION The relationship between cerebral blood flow and white matter indicates a complex interplay between vascular health and white matter alterations in patients with PKU. It highlights the importance of considering a multifactorial model when investigating the impact of PKU on the brain.
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Affiliation(s)
- Leonie Steiner
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Division of Neuropaediatrics, Development and Rehabilitation, Department of Paediatrics, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Raphaela Muri
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Dilmini Wijesinghe
- Laboratory of Functional MRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, USA
| | - Kay Jann
- Laboratory of Functional MRI Technology (LOFT), Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, USA
| | - Stephanie Maissen-Abgottspon
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Piotr Radojewski
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Katarzyna Pospieszny
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Roland Kreis
- Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Claus Kiefer
- Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Michel Hochuli
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Roman Trepp
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland
| | - Regula Everts
- Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism, Inselspital, Bern University Hospital and University of Bern, Switzerland; Division of Neuropaediatrics, Development and Rehabilitation, Department of Paediatrics, Inselspital, Bern University Hospital and University of Bern, Switzerland; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland.
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