We wanted to verify the effect of combining multi-echo (ME) functional magnetic resonance imaging (fMRI) with slice acceleration in simultaneous multi-slice acquisition. The aim was to shed light on the benefits of multiple echoes for various acquisition settings, especially for levels of slice acceleration and flip angle. Whole-brain ME fMRI data were obtained from 26 healthy volunteers (using three echoes; seven runs with slice acceleration 1, 4, 6, and 8; and two different flip angles for each of the first three acceleration factors) and processed as single-echo (SE) data and ME data based on optimal combinations weighted by the contrast-to-noise ratio. Global metrics (temporal signal-to-noise ratio, signal-to-noise separation, number of active voxels, etc.) and local characteristics in regions of interest were used to evaluate SE and ME data. ME results outperformed SE results in all runs; the differences became more apparent for higher acceleration, where a significant decrease in data quality is observed. ME fMRI can improve the observed data quality metrics over SE fMRI for a wide range of accelerated fMRI acquisitions.
- MeSH
- dospělí MeSH
- echoplanární zobrazování metody MeSH
- globus pallidus diagnostické zobrazování fyziologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- mapování mozku metody MeSH
- mladý dospělý MeSH
- mozková kůra diagnostické zobrazování fyziologie MeSH
- počítačové zpracování obrazu metody MeSH
- psychomotorický výkon fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
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
Clinical benefits of pallidal deep brain stimulation (GPi DBS) in dystonia increase relatively slowly suggesting slow plastic processes in the motor network. Twenty-two patients with dystonia of various distribution and etiology treated by chronic GPi DBS and 22 healthy subjects were examined for short-latency intracortical inhibition of the motor cortex elicited by paired transcranial magnetic stimulation. The relationships between grey matter volume and intracortical inhibition considering the long-term clinical outcome and states of the GPi DBS were analysed. The acute effects of GPi DBS were associated with a shortening of the motor response whereas the grey matter of chronically treated patients with a better clinical outcome showed hypertrophy of the supplementary motor area and cerebellar vermis. In addition, the volume of the cerebellar hemispheres of patients correlated with the improvement of intracortical inhibition which was generally less effective in patients than in controls regardless of the DBS states. Importantly, good responders to GPi DBS showed a similar level of short-latency intracortical inhibition in the motor cortex as healthy controls whereas non-responders were unable to increase it. All these results support the multilevel impact of effective DBS on the motor networks in dystonia and suggest potential biomarkers of responsiveness to this treatment.
- MeSH
- dospělí MeSH
- dystonie terapie MeSH
- globus pallidus fyziologie MeSH
- hluboká mozková stimulace metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- motorické korové centrum fyziologie MeSH
- mozeček fyziologie MeSH
- nervový útlum * MeSH
- senioři MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Although pallidal deep brain stimulation (GPi-DBS) is an effective treatment for dystonia, it may cause important stimulation-induced side-effects such as hypokinetic dysarthria or stuttering. However, the reasons behind the occurrence of these side-effects remain unknown. OBJECTIVE: To objectively investigate the impact of GPi-DBS on patients with dystonia on speech fluency, intelligibility, and key aspects of hyperkinetic and hypokinetic dysarthria. METHODS: Speech was systematically evaluated in 19 dystonic patients with GPi-DBS. Each patient was tested twice within one day in both the GPi-DBS ON and GPi-DBS OFF stimulation conditions. A control sample of 19 matched healthy speakers underwent the same speech assessment. RESULTS: We observed an improvement of hyperkinetic dysarthria symptoms in 47% and an aggravation of hypokinetic dysarthria symptoms in 26% of patients with the GPi-DBS switched ON. A higher stimulus intensity was found in a group of patients in whom the hypokinetic dysarthria worsened with the GPi-DBS ON when compared to other dystonic patients (p = 0.02). Furthermore, we revealed a significant increase of dysfluent words in the GPi-DBS ON when compared to OFF condition (p = 0.001) associated with the shorter distance of the active contact localization along the medio-lateral direction (r = -0.70, p = 0.005). CONCLUSION: This study provides evidence of dualistic effects of GPi-DBS on speech in dystonia manifested as an improvement of hyperkinetic or a deterioration of hypokinetic dysarthria. Our findings suggest that lower stimulation parameters and placement of active contacts more laterally in the internal globus pallidus should be preferred to avoid the possible side effects of hypokinetic dysarthria and dysfluency.
- MeSH
- dospělí MeSH
- dystonie patofyziologie terapie MeSH
- globus pallidus fyziologie MeSH
- hluboká mozková stimulace škodlivé účinky metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- poruchy řeči etiologie patofyziologie terapie MeSH
- průřezové studie MeSH
- senioři MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This study investigates how complex motor-cognitive activities are processed in the subthalamic nucleus (STN) and internal globus pallidum (GPi), as adverse neuropsychiatric effects may accompany deep brain stimulation (DBS), mainly in Parkinson's disease (PD) and STN-DBS. Dystonia patients with GPi-DBS electrodes (n = 5) and PD subjects (n = 5) with STN-DBS electrodes performed two tasks: (1) copying letters; and (2) writing any letter other than that appearing on the monitor. The cognitive load of the second task was greater than that of the first. Intracranial local field potentials (LFPs) were analysed. A beta power decrease was the main correlate of the enhanced cognitive load during the second task in both structures, with a lateralization to the left side, mainly in the GPi. A gamma power increase linked with the increased cognitive activity was observed only in the STN. Differences were also observed in the theta and alpha bandpasses. Beta ERD reactivity seems to be essential during the processing of complex motor-cognitive tasks, increases with enhanced cognitive effort, and was observed in both the STN and GPi. Oscillatory reactivity to effortful cognitive processing in other frequency bands was less consistent, with differences between the studied nuclei. Lateralization of activity related to cognitive factors was observed mainly in the GPi.
- MeSH
- dospělí MeSH
- dystonie patofyziologie terapie MeSH
- elektroencefalografie MeSH
- globus pallidus fyziologie MeSH
- hluboká mozková stimulace * MeSH
- kognice fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- nucleus subthalamicus fyziologie MeSH
- Parkinsonova nemoc patofyziologie terapie MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Deep brain stimulation (DBS) of the globus pallidus interna is an effective tool for the treatment of dystonia with possible distant effects reaching beyond the basal ganglia network. AIM: We analyzed the cortical silent period (CoSP) to test inhibitory circuits at the cortical level, and the cutaneous silent period (CuSP) and the H-reflex to test inhibitory circuits at the spinal level. METHODS: The upper limb muscles of 16 patients (9F, aged 54±(SD)16years) with generalized (N=9) and cervical (N=7) dystonia treated with DBS bilaterally were examined by the CoSP, CuSP and H-reflex in two states with random order: (i) in DBS ON and (ii) in DBS OFF condition two hours later, and compared with healthy controls. RESULTS: While the CuSP and H-Reflex did not differ between groups and remained unaffected by DBS, the CoSP was influenced significantly in dystonia. The CoSP onset latency was shortened (p<0.05 corrected) and the CoSP duration prolonged (p<0.01 corrected) in ON versus OFF condition. This effect was especially larger in generalized or phasic type of dystonia. Compared to healthy controls, the CoSP latency and duration became shorter in patients during the OFF condition only. CONCLUSION: The pallidal DBS did not affect the spinal inhibitory circuitry in dystonia. However, the abnormally low cortical inhibition was normalized after DBS possibly offering more efficient suppression of aberrant dystonic movements.
- MeSH
- dospělí MeSH
- dystonie terapie MeSH
- globus pallidus fyziologie MeSH
- H-reflex fyziologie MeSH
- hluboká mozková stimulace metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- mícha patofyziologie MeSH
- mladý dospělý MeSH
- motorické evokované potenciály fyziologie MeSH
- mozková kůra patofyziologie MeSH
- nervový útlum fyziologie MeSH
- senioři MeSH
- šířící se kortikální deprese fyziologie MeSH
- stupeň závažnosti nemoci MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
This paper explores the development of multi-feature classification techniques used to identify tremor-related characteristics in the Parkinsonian patient. Local field potentials were recorded from the subthalamic nucleus and the globus pallidus internus of eight Parkinsonian patients through the implanted electrodes of a Deep brain stimulation (DBS) device prior to device internalization. A range of signal processing techniques were evaluated with respect to their tremor detection capability and used as inputs in a multi-feature neural network classifier to identify the activity of Parkinsonian tremor. The results of this study show that a trained multi-feature neural network is able, under certain conditions, to achieve excellent detection accuracy on patients unseen during training. Overall the tremor detection accuracy was mixed, although an accuracy of over 86% was achieved in four out of the eight patients.
- MeSH
- časové faktory MeSH
- elektromyografie MeSH
- evokované potenciály fyziologie MeSH
- globus pallidus fyziologie MeSH
- hluboká mozková stimulace metody MeSH
- implantované elektrody MeSH
- lidé MeSH
- neuronové sítě (počítačové) MeSH
- nucleus subthalamicus fyziologie MeSH
- Parkinsonova nemoc komplikace terapie MeSH
- spektrální analýza MeSH
- tremor diagnóza etiologie patologie terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We studied the appearance of cognitive event-related potentials (ERPs) and event-related de/synchronizations (ERD/S) in the subthalamic nucleus (STN) and globus pallidus internus (GPi). We particularly focused on the rare non-target (distractor) stimuli processing. ERPs and ERD/S in the alpha and beta frequency range were analyzed in seven Parkinson's disease patients and one primary dystonia patient with implanted deep brain stimulation (DBS) electrodes. A visual three-stimulus protocol was used (frequent stimulus, target stimulus, and distractor). The non-target and distractor-related waveforms manifested similar shapes. A specific positive ERP peak around 200 ms and a low alpha frequency ERS were detected from the STN as a response to the distractor stimuli in six of the patients with Parkinson's disease and also in the primary dystonia patient's GPi. This positivity probably reflects an attentional orienting response to the distractor stimuli. The STN and GPi are probably involved in attentional cerebral networks.
- MeSH
- elektroencefalografie metody MeSH
- evokované potenciály fyziologie MeSH
- globus pallidus fyziologie MeSH
- hluboká mozková stimulace přístrojové vybavení metody MeSH
- implantované elektrody MeSH
- lidé středního věku MeSH
- lidé MeSH
- nucleus subthalamicus fyziologie MeSH
- Parkinsonova nemoc patofyziologie terapie MeSH
- pozornost fyziologie MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- MeSH
- dítě MeSH
- globus pallidus fyziologie MeSH
- hluboká mozková stimulace * metody MeSH
- lidé MeSH
- spina bifida * terapie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH