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Jörn Kaufmann

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7 papers

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YNICL Journal 2025 Journal Article

Association between white matter microstructural changes and aggressiveness. A case-control diffusion tensor imaging study

Stephanie Seidenbecher
Jörn Kaufmann
Maria Schöne
Henrik Dobrowolny
Kolja Schiltz
Thomas Frodl
Johann Steiner
Bernhard Bogerts

Research has focused on identifying neurobiological risk factors associated with aggressive behavior in order to improve prevention and treatment efforts. This study aimed to characterize microstructural differences in white matter (WM) integrity in individuals prone to aggression. We hypothesized that altered cerebral WM microstructure may underlie normal individual variability in aggression and tested this using a case-control design in healthy individuals. Diffusion tensor imaging (DTI) was used to examine WM changes in martial artists (n = 29) and age-matched controls (n = 31). We performed tract-based spatial statistics (TBSS) to identify differences in axial diffusivity (AD), fractional anisotropy (FA) and mean diffusivity (MD) between the two groups at the whole-brain level. Martial artists were significantly more aggressive than controls, with increased MD in parietal and occipital areas and increased AD in widespread fiber tracts in the frontal, parietal and temporal areas. Positive associations between AD/MD and (physical) appetitive aggression were identified in several clusters, including the corpus callosum, the superior longitudinal fasciculus and the corona radiata. Our study found evidence for WM microstructural changes associated with aggressiveness in a community case-control sample. Longitudinal studies with larger cohorts, taking into account the dimensional nature of aggressiveness, are needed to better understand the underlying neurobiology.

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YNIMG Journal 2022 Journal Article

Test-retest reliability of multi-parametric maps (MPM) of brain microstructure

Norman Aye
Nico Lehmann
Jörn Kaufmann
Hans-Jochen Heinze
Emrah Düzel
Marco Taubert
Gabriel Ziegler

Multiparameter mapping (MPM) is a quantitative MRI protocol that is promising for studying microstructural brain changes in vivo with high specificity. Reliability values are an important prior knowledge for efficient study design and facilitating replicable findings in development, aging and neuroplasticity research. To explore longitudinal reliability of MPM we acquired the protocol in 31 healthy young subjects twice over a rescan interval of 4 weeks. We assessed the within-subject coefficient of variation (WCV), the between-subject coefficient of variation (BCV), and the intraclass correlation coefficient (ICC). Using these metrics, we investigated the reliability of (semi-) quantitative magnetization transfer saturation (MTsat), proton density (PD), transversal relaxation (R2*) and longitudinal relaxation (R1). To increase relevance for explorative studies in development and training-induced plasticity, we assess reliability both on local voxel- as well as ROI-level. Finally, we disentangle contributions and interplay of within- and between-subject variability to ICC and assess the optimal degree of spatial smoothing applied to the data. We reveal evidence that voxelwise ICC reliability of MPMs is moderate to good with median values in cortex (subcortical GM): MT: 0. 789 (0. 447) PD: 0. 553 (0. 264) R1: 0. 555 (0. 369) R2*: 0. 624 (0. 477). The Gaussian smoothing kernel of 2 to 4 mm FWHM resulted in optimal reproducibility. We discuss these findings in the context of longitudinal intervention studies and the application to research designs in neuroimaging field.

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YNICL Journal 2020 Journal Article

Sonographic and 3T-MRI-based evaluation of the tongue in ALS

Nathalie Hensiek
Frank Schreiber
Thomas Wimmer
Jörn Kaufmann
Judith Machts
Laura Fahlbusch
Cornelia Garz
Susanne Vogt

A few systematic imaging studies employing ultrasound (HRUS) and magnetic resonance imaging (MRI) have suggested tongue measures to aid in diagnosis of amyotrophic lateral sclerosis (ALS). The relationship between structural tongue alterations and the ALS patients' bulbar and overall motor function has not yet been elucidated. We here thus aimed to understand how in-vivo tongue alterations relate to motor function and motor function evolution over time in ALS. Our study included 206 ALS patients and 104 age- and sex-matched controls that underwent HRUS and 3T MRI of the tongue at baseline. Sonographic measures comprised coronal tongue echointensity, area, height, width and height/width ratio, while MRI measures comprised sagittal T1 intensity, tongue area, position and shape. Imaging-derived markers were related to baseline and longitudinal bulbar and overall motor function. Baseline T1 intensity was lower in ALS patients with more severe bulbar involvement at baseline. Smaller baseline coronal (HRUS) and sagittal (MRI) tongue area, smaller coronal height (HRUS) and width (HRUS) as well as more rounded sagittal tongue shape predicated more rapid functional impairment - not only of bulbar, but also of overall motor function - in ALS. Our results suggest that in-vivo sonography und MRI tongue measures could aid as biomarkers to reflect bulbar and motor function impairment.

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YNICL Journal 2019 Journal Article

Quantifying nerve decussation abnormalities in the optic chiasm

Robert J. Puzniak
Khazar Ahmadi
Jörn Kaufmann
Andre Gouws
Antony B. Morland
Franco Pestilli
Michael B. Hoffmann

OBJECTIVE: The human optic chiasm comprises partially crossing optic nerve fibers. Here we used diffusion MRI (dMRI) for the in-vivo identification of the abnormally high proportion of crossing fibers found in the optic chiasm of people with albinism. METHODS: In 9 individuals with albinism and 8 controls high-resolution 3T dMRI data was acquired and analyzed with a set of methods for signal modeling [Diffusion Tensor (DT) and Constrained Spherical Deconvolution (CSD)], tractography, and streamline filtering (LiFE, COMMIT, and SIFT2). The number of crossing and non-crossing streamlines and their weights after filtering entered ROC-analyses to compare the discriminative power of the methods based on the area under the curve (AUC). The dMRI results were cross-validated with fMRI estimates of misrouting in a subset of 6 albinotic individuals. RESULTS: = 0.83, p = 0.012). The results show that streamline filtering methods in combination with probabilistic tracking, both optimized for the data at hand, can improve the detection of crossing in the human optic chiasm. CONCLUSIONS: Especially CSD-based tractography provides an efficient approach to detect structural abnormalities in the optic chiasm. The most realistic results were obtained with filtering methods with parameters optimized for the data at hand. SIGNIFICANCE: Our findings demonstrate a novel anatomy-driven approach for the individualized diagnostics of optic chiasm abnormalities.

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YNICL Journal 2016 Journal Article

Interhemispheric connectivity in amyotrophic lateral sclerosis: A near-infrared spectroscopy and diffusion tensor imaging study

Klaus Kopitzki
Andreas Oldag
Catherine M. Sweeney-Reed
Judith Machts
Maria Veit
Jörn Kaufmann
Hermann Hinrichs
Hans-Jochen Heinze

PURPOSE: Aim of the present study was to investigate potential impairment of non-motor areas in amyotrophic lateral sclerosis (ALS) using near-infrared spectroscopy (NIRS) and diffusion tensor imaging (DTI). In particular, we evaluated whether homotopic resting-state functional connectivity (rs-FC) of non-motor associated cortical areas correlates with clinical parameters and disease-specific degeneration of the corpus callosum (CC) in ALS. MATERIAL AND METHODS: Interhemispheric homotopic rs-FC was assessed in 31 patients and 30 healthy controls (HCs) for 8 cortical sites, from prefrontal to occipital cortex, using NIRS. DTI was performed in a subgroup of 21 patients. All patients were evaluated for cognitive dysfunction in the executive, memory, and visuospatial domains. RESULTS: < 0.05). CONCLUSIONS: The present study further supports involvement of non-motor areas in ALS. Our results render homotopic rs-FC as assessed by NIRS a potential clinical marker for disease progression rate in ALS patients without executive dysfunction and a potential anatomical marker for ALS-specific degeneration of the CC and CSTs.

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YNICL Journal 2014 Journal Article

Structural and functional hallmarks of amyotrophic lateral sclerosis progression in motor- and memory-related brain regions

Christian Michael Stoppel
Stefan Vielhaber
Cindy Eckart
Judith Machts
Jörn Kaufmann
Hans-Jochen Heinze
Katja Kollewe
Susanne Petri

Previous studies have shown that in amyotrophic lateral sclerosis (ALS) multiple motor and extra-motor regions display structural and functional alterations. However, their temporal dynamics during disease-progression are unknown. To address this question we employed a longitudinal design assessing motor- and novelty-related brain activity in two fMRI sessions separated by a 3-month interval. In each session, patients and controls executed a Go/NoGo-task, in which additional presentation of novel stimuli served to elicit hippocampal activity. We observed a decline in the patients' movement-related activity during the 3-month interval. Importantly, in comparison to controls, the patients' motor activations were higher during the initial measurement. Thus, the relative decrease seems to reflect a breakdown of compensatory mechanisms due to progressive neural loss within the motor-system. In contrast, the patients' novelty-evoked hippocampal activity increased across 3 months, most likely reflecting the build-up of compensatory processes typically observed at the beginning of lesions. Consistent with a stage-dependent emergence of hippocampal and motor-system lesions, we observed a positive correlation between the ALSFRS-R or MRC-Megascores and the decline in motor activity, but a negative one with the hippocampal activation-increase. Finally, to determine whether the observed functional changes co-occur with structural alterations, we performed voxel-based volumetric analyses on magnetization transfer images in a separate patient cohort studied cross-sectionally at another scanning site. Therein, we observed a close overlap between the structural changes in this cohort, and the functional alterations in the other. Thus, our results provide important insights into the temporal dynamics of functional alterations during disease-progression, and provide support for an anatomical relationship between functional and structural cerebral changes in ALS.

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YNIMG Journal 2008 Journal Article

Contemporary ultrasound systems allow high-resolution transcranial imaging of small echogenic deep intracranial structures similarly as MRI: A phantom study

Uwe Walter
Martin Kanowski
Jörn Kaufmann
Annette Grossmann
Reiner Benecke
Ludwig Niehaus

Transcranial sonography (TCS) of small deep brain structures, such as substantia nigra and brainstem raphe, is increasingly used for assessment of neurodegenerative disorders. Still, there are reservations against TCS because of the smallness of evaluated structures and constraints on image resolution that is discussed to be lower compared to magnetic resonance imaging (MRI). To evaluate two different-generation TCS systems in visualizing fine intracranial structures, we studied image resolution on a phantom consisting of 0. 80 mm×1. 05 mm regular meshwork of nylon threads embedded in a wet, gel-filled ex vivo human skull. Imaging was performed with a former-generation and a present-day clinical ultrasound system and for comparison with MRI. In axial direction of insonation both TCS systems resolved 0. 80-mm and 1. 05-mm thread-to-thread distance at depths between 55 and 120 mm using transmission frequencies ≥2. 5 MHz. The meshwork, however, was recognizable as such only with the contemporary TCS system at depths between 60 and 85 mm due to its higher lateral resolution. MRI resolved the meshwork if image resolution was chosen sufficiently high but not if realistic clinical conditions were applied with its trade-offs between image SNR, resolution, total scan time, and unavoidable head motion during the latter. Hence, if the requirements for optimal TCS image resolution are fulfilled, i. e. sufficient acoustic bone window, increased echogenicity of target structure and its localization in a distance of maximum ±15 mm from midsagittal plane, findings suggest that contemporary TCS systems achieve higher image resolution of intracranial structures in comparison not only to former-generation systems, but also to MRI under clinical conditions.

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