@article{LiebeDordevicKaufmannetal.2022, author = {Liebe, Thomas and Dordevic, Milos and Kaufmann, J{\"o}rn and Avetisyan, Araks and Skalej, Martin and M{\"u}ller, Notger Germar}, title = {Investigation of the functional pathogenesis of mild cognitive impairment by localisation-based locus coeruleus resting-state fMRI}, series = {Human Brain Mapping}, volume = {43}, journal = {Human Brain Mapping}, edition = {18}, publisher = {Wiley}, address = {New York, NY, USA}, issn = {1097-0193}, doi = {10.1002/hbm.26039}, pages = {5630 -- 5642}, year = {2022}, abstract = {Dementia as one of the most prevalent diseases urges for a better understanding of the central mechanisms responsible for clinical symptoms, and necessitates improvement of actual diagnostic capabilities. The brainstem nucleus locus coeruleus (LC) is a promising target for early diagnosis because of its early structural alterations and its relationship to the functional disturbances in the patients. In this study, we applied our improved method of localisation-based LC resting-state fMRI to investigate the differences in central sensory signal processing when comparing functional connectivity (fc) of a patient group with mild cognitive impairment (MCI, n = 28) and an age-matched healthy control group (n = 29). MCI and control participants could be differentiated in their Mini-Mental-State-Examination (MMSE) scores (p < .001) and LC intensity ratio (p = .010). In the fMRI, LC fc to anterior cingulate cortex (FDR p < .001) and left anterior insula (FDR p = .012) was elevated, and LC fc to right temporoparietal junction (rTPJ, FDR p = .012) and posterior cingulate cortex (PCC, FDR p = .021) was decreased in the patient group. Importantly, LC to rTPJ connectivity was also positively correlated to MMSE scores in MCI patients (p = .017). Furthermore, we found a hyperactivation of the left-insula salience network in the MCI patients. Our results and our proposed disease model shed new light on the functional pathogenesis of MCI by directing to attentional network disturbances, which could aid new therapeutic strategies and provide a marker for diagnosis and prediction of disease progression.}, language = {en} } @article{DordevicHoelzerRussoetal.2022, author = {Dordevic, Milos and H{\"o}lzer, Sonja and Russo, Augusta and Garc{\´i}a Alanis, Jos{\´e} Carlos and M{\"u}ller, Notger Germar}, title = {The Role of the Precuneus in Human Spatial Updating in a Real Environment Setting—A cTBS Study}, series = {Life}, volume = {12}, journal = {Life}, edition = {8}, publisher = {MDPI}, address = {Basel, Schweiz}, issn = {2075-1729}, doi = {10.3390/life12081239}, pages = {1 -- 13}, year = {2022}, abstract = {As we move through an environment, we update positions of our body relative to other objects, even when some objects temporarily or permanently leave our field of view—this ability is termed egocentric spatial updating and plays an important role in everyday life. Still, our knowledge about its representation in the brain is still scarce, with previous studies using virtual movements in virtual environments or patients with brain lesions suggesting that the precuneus might play an important role. However, whether this assumption is also true when healthy humans move in real environments where full body-based cues are available in addition to the visual cues typically used in many VR studies is unclear. Therefore, in this study we investigated the role of the precuneus in egocentric spatial updating in a real environment setting in 20 healthy young participants who underwent two conditions in a cross-over design: (a) stimulation, achieved through applying continuous theta-burst stimulation (cTBS) to inhibit the precuneus and (b) sham condition (activated coil turned upside down). In both conditions, participants had to walk back with blindfolded eyes to objects they had previously memorized while walking with open eyes. Simplified trials (without spatial updating) were used as control condition, to make sure the participants were not affected by factors such as walking blindfolded, vestibular or working memory deficits. A significant interaction was found, with participants performing better in the sham condition compared to real stimulation, showing smaller errors both in distance and angle. The results of our study reveal evidence of an important role of the precuneus in a real-environment egocentric spatial updating; studies on larger samples are necessary to confirm and further investigate this finding.}, language = {en} } @article{HeroldLabottGraessleretal.2022, author = {Herold, Fabian and Labott, Berit K. and Gr{\"a}ssler, Bernhard and Halfpaap, Nicole and Langhans, Corinna and M{\"u}ller, Patrick and Ammar, Achraf and Dordevic, Milos and H{\"o}kelmann, Anita and M{\"u}ller, Notger Germar}, title = {A Link between Handgrip Strength and Executive Functioning: A Cross-Sectional Study in Older Adults with Mild Cognitive Impairment and Healthy Controls}, series = {Healthcare : open access journal}, volume = {10}, journal = {Healthcare : open access journal}, edition = {2}, publisher = {MDPI}, address = {Basel, Schweiz}, issn = {2227-9032}, doi = {10.3390/healthcare10020230}, pages = {1 -- 14}, year = {2022}, abstract = {Older adults with amnestic mild cognitive impairment (aMCI) who in addition to their memory deficits also suffer from frontal-executive dysfunctions have a higher risk of developing dementia later in their lives than older adults with aMCI without executive deficits and older adults with non-amnestic MCI (naMCI). Handgrip strength (HGS) is also correlated with the risk of cognitive decline in the elderly. Hence, the current study aimed to investigate the associations between HGS and executive functioning in individuals with aMCI, naMCI and healthy controls. Older, right-handed adults with amnestic MCI (aMCI), non-amnestic MCI (naMCI), and healthy controls (HC) conducted a handgrip strength measurement via a handheld dynamometer. Executive functions were assessed with the Trail Making Test (TMT A\&B). Normalized handgrip strength (nHGS, normalized to Body Mass Index (BMI)) was calculated and its associations with executive functions (operationalized through z-scores of TMT B/A ratio) were investigated through partial correlation analyses (i.e., accounting for age, sex, and severity of depressive symptoms). A positive and low-to-moderate correlation between right nHGS (rp (22) = 0.364; p = 0.063) and left nHGS (rp (22) = 0.420; p = 0.037) and executive functioning in older adults with aMCI but not in naMCI or HC was observed. Our results suggest that higher levels of nHGS are linked to better executive functioning in aMCI but not naMCI and HC. This relationship is perhaps driven by alterations in the integrity of the hippocampal-prefrontal network occurring in older adults with aMCI. Further research is needed to provide empirical evidence for this assumption.}, language = {en} } @article{HeroldTheobaldGronwaldetal.2022, author = {Herold, Fabian and Theobald, Paula and Gronwald, Thomas and Rapp, Michael Armin and M{\"u}ller, Notger Germar}, title = {Going digital - a commentary on the terminology used at the intersection of physical activity and digital health}, series = {European review of aging and physical activity}, volume = {19}, journal = {European review of aging and physical activity}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {1861-6909}, doi = {10.1186/s11556-022-00296-y}, pages = {7}, year = {2022}, abstract = {In recent years digital technologies have become a major means for providing health-related services and this trend was strongly reinforced by the current Coronavirus disease 2019 (COVID-19) pandemic. As it is well-known that regular physical activity has positive effects on individual physical and mental health and thus is an important prerequisite for healthy aging, digital technologies are also increasingly used to promote unstructured and structured forms of physical activity. However, in the course of this development, several terms (e.g., Digital Health, Electronic Health, Mobile Health, Telehealth, Telemedicine, and Telerehabilitation) have been introduced to refer to the application of digital technologies to provide health-related services such as physical interventions. Unfortunately, the above-mentioned terms are often used in several different ways, but also relatively interchangeably. Given that ambiguous terminology is a major source of difficulty in scientific communication which can impede the progress of theoretical and empirical research, this article aims to make the reader aware of the subtle differences between the relevant terms which are applied at the intersection of physical activity and Digital Health and to provide state-of-art definitions for them.}, language = {en} }