Ageing is a complex phenomenon affecting a wide range of coexisting biological processes. The homogeneity of the studied population is an essential parameter for valid interpretations of outcomes. The presented study capitalises on the MRI data available in the Human Connectome Project-Aging (HCP-A) and, within individuals over 55 years of age who passed the HCP-A section criteria, compares a subgroup of 37 apparently neurocognitively healthy individuals selected based on stringent criteria with 37 age and sex-matched individuals still representative of typical ageing but who did not pass the stringent definition of neurocognitively healthy. Specifically, structural scans, diffusion weighted imaging and T1w/T2w ratio were utilised. Furthermore, data of 26 HCP-A participants older than 90 years as notional 'super-agers' were analysed. The relationship of age and several microstructural MRI metrics (T1w/T2w ratio, mean diffusivity, intracellular volume fraction and free water volume fraction) differed significantly between typical and healthy ageing cohort in areas highly relevant for ageing such as hippocampus, prefrontal and temporal cortex and cerebellum. However, the trajectories of the healthy ageing population did not show substantially better overlap with the findings in people older than 90 than those of the typical population. Therefore, caution must be exercised in the choice of adequate study group characteristics relevant for respective ageing-related hypotheses. Contrary to typical ageing group, the healthy ageing cohort may show generally stable levels of several MRI metrics of interest.
- MeSH
- kognice * fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mozek diagnostické zobrazování MeSH
- šedá hmota * diagnostické zobrazování MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- stárnutí * fyziologie MeSH
- zdravé stárnutí fyziologie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
BACKGROUND: The research on possible cerebral involvement in Crohn's disease (CD) has been largely marginalized and failed to capitalize on recent developments in magnetic resonance imaging (MRI). OBJECTIVE: This cross-sectional pilot study searches for eventual macrostructural and microstructural brain affection in CD in remission and early after the disease onset. METHODS: 14 paediatric CD patients and 14 healthy controls underwent structural, diffusion weighted imaging and quantitative relaxation metrics acquisition, both conventional free precession and adiabatic rotating frame transverse and longitudinal relaxation time constants as markers of myelination, iron content and cellular loss. RESULTS: While no inter-group differences in cortical thickness and relaxation metrics were found, lower mean diffusivity and higher intracellular volume fraction were detected in CD patients over vast cortical regions essential for the regulation of the autonomous nervous system, sensorimotor processing, cognition and behavior, pointing to wide-spread cytotoxic oedema in the absence of demyelination, iron deposition or atrophy. CONCLUSION: Although still requiring further validation in longitudinal projects enrolling larger numbers of subjects, this study provides an indication of wide-spread cortical oedema in CD patients very early after the disease onset and sets possible directions for further research.
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND OBJECTIVES: The intricate relationship between deep brain stimulation (DBS) in Parkinson's disease (PD) and cognitive impairment has lately garnered substantial attention. The presented study evaluated pre-DBS structural and microstructural cerebral patterns as possible predictors of future cognitive decline in PD DBS patients. METHODS: Pre-DBS MRI data in 72 PD patients were combined with neuropsychological examinations and follow-up for an average of 2.3 years after DBS implantation procedure using a screening cognitive test validated for diagnosis of mild cognitive impairment in PD in a Czech population - Dementia Rating Scale 2. RESULTS: PD patients who would exhibit post-DBS cognitive decline were found to have, already at the pre-DBS stage, significantly lower cortical thickness and lower microstructural complexity than cognitively stable PD patients. Differences in the regions directly related to cognition as bilateral parietal, insular and cingulate cortices, but also occipital and sensorimotor cortex were detected. Furthermore, hippocampi, putamina, cerebellum and upper brainstem were implicated as well, all despite the absence of pre-DBS differences in cognitive performance and in the position of DBS leads or stimulation parameters between the two groups. CONCLUSIONS: Our findings indicate that the cognitive decline in the presented PD cohort was not attributable primarily to DBS of the subthalamic nucleus but was associated with a clinically silent structural and microstructural predisposition to future cognitive deterioration present already before the DBS system implantation.
- MeSH
- hluboká mozková stimulace * škodlivé účinky MeSH
- kognitivní dysfunkce * etiologie diagnostické zobrazování patofyziologie patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie * metody MeSH
- neuropsychologické testy MeSH
- nucleus subthalamicus * diagnostické zobrazování MeSH
- Parkinsonova nemoc * terapie diagnostické zobrazování patologie MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Parkinson's disease (PD), even though generally perceived as a dominantly motor disorder, is associated with a wide range of non-motor symptoms, including mixed anxiety-depressive disorder (MADD). OBJECTIVES: The aim of the presented study was to determine whether deep brain stimulation (DBS) of the subthalamic nucleus (STN) brings the functional characteristics of non-motor networks closer to the condition detected in healthy population and whether pre-DBS presence of MADD in PD patients was associated with different reaction to this therapeutic modality. METHODS: Resting-state fMRI signature elicited by STN DBS activation and deactivation in 81 PD patients was compared against healthy controls, with the focus on measures of efficiency of information processing and localised subnetwork differences. RESULTS: While all the MRI metrics showed statistically significant differences between PD patients in DBS OFF condition and healthy controls, none were detected in such a comparison against DBS ON condition. Furthermore, in the post-DBS evaluation, PD patients with MADD in the pre-DBS stage showed no differences in depression scales compared to pre-DBS psychiatrically intact PD patients, but still exhibited lower DBS-related connectivity in a subnetwork encompassing anterior and posterior cingulate, dorsolateral prefrontal and medial temporal cortices. CONCLUSIONS: STN DBS improved all the metrics of interest towards the healthy state, normalising the resting-state MRI signature of PD. Furthermore, pre-DBS presence of MADD, even though clinically silent at post-DBS MRI acquisition, was associated with lower DBS effect in areas highly relevant for depression. This finding points to a possibly latent nature of post-DBS MADD, calling for caution in further follow-up of these patients.
- Publikační typ
- časopisecké články MeSH
The advent of new, advanced quantitative MRI metrics allows for in vivo evaluation of multiple biological processes highly relevant for ageing. The presented study combines several MRI parameters hypothesised to detect distinct biological characteristics as myelin density, cellularity, cellular membrane integrity and iron concentration. 116 healthy volunteers, continuously distributed over the whole adult age span, underwent a multi-modal MRI protocol acquisition. Scatterplots of individual MRI metrics revealed that certain MRI protocols offer much higher sensitivity to early adulthood changes while plateauing in higher age (e.g., global functional connectivity in cerebral cortex or orientation dispersion index in white matter), while other MRI metrics provided reverse ability-stable levels in young adulthood with sharp changes with rising age (e.g., T1ρ and T2ρ). Nonetheless, despite the previously published validations of specificity towards microstructural biology based on cytoarchitectonic maps in healthy population or alterations in certain pathologies, several metrics previously hypothesised to be selective to common measures failed to show similar scatterplot distributions, pointing to further confounding factors directly related to age. Furthermore, other metrics, previously shown to detect different biological characteristics, exhibited substantial intercorrelations, be it due to the nature of the MRI protocol itself or co-dependence of relevant biological microstructural processes. All in all, the presented study provides a unique basis for the design and choice of relevant MRI parameters depending on the age group of interest. Furthermore, it calls for caution in simplistic biological inferences in ageing based on one simple MRI metric, even though previously validated under other conditions. Complex multi-modal approaches combining several metrics to extract the shared subcomponent will be necessary to achieve the desired goal of histological MRI.
- Publikační typ
- časopisecké články MeSH
Tremor je nejčastějším extrapyramidovým syndromem s mnoha potenciálními příčinami. V klinické praxi se používá mnoho přípravků, které mohou třes exacerbovat nebo přímo vyvolat. Z nejčastějších lze zmínit amiodaron, valproát, antagonisty dopaminu, lithium, inhibitory zpětného vychytávání serotoninu (a noradrenalinu) (SSRI/SNRI) a amitriptylin. Polékové třesy mají obvykle charakter akcentovaného fyziologického třesu, ale v závislosti od příčinného léčiva se může jednat o třes v rámci polékového parkinsonismu. Znalost tremorogenních léků může napomoci rychlé diagnostice, předejít zbytečným testům a umožnit adekvátní kroky - obvykle snížení dávky či vysazení příslušného přípravku nebo jeho náhradu za jiný. Cílem tohoto přehledu je poskytnout lékařům a farmaceutům aktuální informace o skupinách léků, u kterých je nutno pomýšlet na potenciální asociaci s třesem, a informace o možnostech řešení této komplikace.
Tremor is the most common movement disorder with several potential causes. There is a multitude of drugs utilised in the clinical practice, which may exacerbate or even cause tremor, the most common ones being amiodarone, valproate, dopamine receptor antagonists, lithium, selective serotonin (and norepinephrine) reuptake inhibitors (SSRI/SNRI) and amitriptyline. Drug-induced tremors usually correspond to enhanced physiological tremor, but, depending on the causal drug, the tremor may be a part of drug-induced parkinsonism. The recognition of tremorgenic drugs may help quick diagnosis, avoid unnecessary tests and lead to adequate actions - usually dose decrease or discontinuation of relevant drug, or its substitution. The aim of this review is to provide physicians and pharmacists with current information on the groups of drugs where a potential association with tremor is to be considered, including the information on possible management of this complication.
BACKGROUND: Deep brain stimulation of the internal globus pallidus (GPi DBS) is an invasive therapeutic modality intended to retune abnormal central nervous system patterns and relieve the patient of dystonic or other motor symptoms. OBJECTIVES: The aim of the presented research was to determine the neuroanatomical signature of GPi DBS modulation and its association with the clinical outcome. METHODS: This open-label fixed-order study with cross-sectional validation against healthy controls analysed the resting-state functional MRI activity changes induced by GPi DBS in 18 dystonia patients of heterogeneous aetiology, focusing on both global (full brain) and local connectivity (local signal homogeneity). RESULTS: Compared to the switched-off state, the activation of GPi DBS led to the restoration of global subcortical connectivity patterns (in both putamina, diencephalon and brainstem) towards those of healthy controls, with positive direct correlation over large-scale cortico-basal ganglia-thalamo-cortical and cerebellar networks with the clinical improvement. Nonetheless, on average, GPi DBS also seemed to bring local connectivity both in the cortical and subcortical regions farther away from the state detected in healthy controls. Interestingly, its correlation with clinical outcome showed that in better DBS responders, local connectivity defied this effect and approached healthy controls. CONCLUSIONS: All in all, the extent of restoration of both these main metrics of interest towards the levels found in healthy controls clearly correlated with the clinical improvement, indicating that the restoration of network state towards more physiological condition may be a precondition for successful GPi DBS outcome in dystonia.
- MeSH
- dystonie * terapie MeSH
- globus pallidus fyziologie MeSH
- hluboká mozková stimulace * MeSH
- lidé MeSH
- průřezové studie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Tremor je nejčastějším extrapyramidovým syndromem s mnoha potenciálními příčinami. V klinické praxi se používá mnoho přípravků, které mohou třes exacerbovat nebo přímo vyvolat. Z nejčastějších lze zmínit amiodaron, valproát, antagonisty dopaminu, lithium, inhibitory zpětného vychytávání serotoninu (a noradrenalinu) (SSRI/SNRI) a amitriptylin. Polékové třesy mají obvykle charakter akcentovaného fyziologického třesu, ale v závislosti od příčinného léčiva se může jednat o třes v rámci polékového parkinsonismu. Znalost tremorogenních léků může napomocti rychlé diagnostice, předejít zbytečným testům a umožnit adekvátní kroky - obvykle snížení dávky či vysazení příslušného přípravku nebo jeho náhradu za jiný. Cílem tohoto přehledu je poskytnout lékařům a farmaceutům aktuální informace o skupinách léků, u kterých je nutno pomýšlet na potenciální asociaci s třesem, a informace o možnostech řešení této komplikace.
Tremor is the most common movement disorder with several potential causes. There is a multitude of drugs utilised in the clinical practice, which may exacerbate or even cause tremor, the most common ones being amiodarone, valproate, dopamine receptor antagonists, lithium, selective serotonin (and norepinephrine) reuptake inhibitors (SSRI/SNRI) and amitriptyline. Drug-induced tremors usually correspond to enhanced physiological tremor, but, depending on the causal drug, the tremor may be a part of drug-induced parkinsonism. The recognition of tremorgenic drugs may help quick diagnosis, avoid unnecessary tests and lead to adequate actions - usually dose decrease or discontinuation of relevant drug, or its substitution. The aim of this review is to provide physicians and pharmacists with current information on the groups of drugs where a potential association with tremor is to be considered, including the information on possible management of this complication.
- MeSH
- extrapyramidové dráhy účinky léků MeSH
- léčivé přípravky MeSH
- lidé MeSH
- nežádoucí účinky léčiv * MeSH
- tremor * chemicky indukované diagnóza patofyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
PURPOSE: Neuroimaging pipelines have long been known to generate mildly differing results depending on various factors, including software version. While considered generally acceptable and within the margin of reasonable error, little is known about their effect in common research scenarios such as inter-group comparisons between healthy controls and various pathological conditions. The aim of the presented study was to explore the differences in the inferences and statistical significances in a model situation comparing volumetric parameters between healthy controls and type 1 diabetes patients using various FreeSurfer versions. METHODS: T1- and T2-weighted structural scans of healthy controls and type 1 diabetes patients were processed with FreeSurfer 5.3, FreeSurfer 5.3 HCP, FreeSurfer 6.0 and FreeSurfer 7.1, followed by inter-group statistical comparison using outputs of individual FreeSurfer versions. RESULTS: Worryingly, FreeSurfer 5.3 detected both cortical and subcortical volume differences out of the preselected regions of interest, but newer versions such as FreeSurfer 5.3 HCP and FreeSurfer 6.0 reported only subcortical differences of lower magnitude and FreeSurfer 7.1 failed to find any statistically significant inter-group differences. CONCLUSION: Since group averages of individual FreeSurfer versions closely matched, in keeping with previous literature, the main origin of this disparity seemed to lie in substantially higher within-group variability in the model pathological condition. Ergo, until validation in common research scenarios as case-control comparison studies is included into the development process of new software suites, confirmatory analyses utilising a similar software based on analogous, but not fully equivalent principles, might be considered as supplement to careful quality control.
INTRODUCTION: Despite substantial clinical and pathophysiological differences, the characteristics of tremor in Parkinson's disease (PD) and essential tremor (ET) patients bear certain similarities. The presented study delineates tremor-related structural networks in these two disorders. METHODS: 42 non-advanced PD patients (18 tremor-dominant, 24 without substantial tremor), 17 ET, and 45 healthy controls underwent high-angular resolution diffusion-weighted imaging acquisition to reconstruct their structural motor connectomes as a proxy of the anatomical interconnections between motor network regions, implementing state-of-the-art globally optimised probabilistic tractography. RESULTS: When compared to healthy controls, ET patients exhibited higher structural connectivity in the cerebello-thalamo-cortical network. Interestingly, the comparison of tremor-dominant PD patients and PD patients without tremor yielded very similar results - higher structural connectivity in tremor-dominant PD sharing multiple nodes with the tremor network detected in ET, despite the generally lower structural connectivity between basal ganglia and frontal cortex in the whole PD group when compared to healthy controls. CONCLUSION: The higher structural connectivity of the cerebello-thalamo-cortical network seems to be the dominant tremor driver in both PD and ET. While it appears to be the only tremor-related network in ET, its combination with large scale hypoconnectivity in the frontal cortico-subcortical network in PD may explain different clinical features of tremor in these two disorders.
