RESUMO
Comprehensive understanding of the neural circuits involving the ventral tegmental area is essential for elucidating the anatomo-functional mechanisms governing human behaviour as well as the therapeutic and adverse effects of deep brain stimulation for neuropsychiatric diseases. While the ventral tegmental area has been successfully targeted with deep brain stimulation for different neuropsychiatric diseases, the axonal connectivity of the region has not been fully understood. Here using fiber micro-dissections in human cadaveric hemispheres, population-based high-definition fiber tractography, and previously reported deep brain stimulation hotspots, we find that the ventral tegmental area participates in an intricate network involving the serotonergic pontine nuclei, basal ganglia, limbic system, basal forebrain, and prefrontal cortex, which is implicated in the treatment of obsessive-compulsive disorder, major depressive disorder, Alzheimer's disease, cluster headaches, and aggressive behaviors.
RESUMO
The auditory oddball is a mainstay in research on attention, novelty, and sensory prediction. How this task engages subcortical structures like the subthalamic nucleus and substantia nigra pars reticulata is unclear. We administered an auditory OB task while recording single unit activity (35 units) and local field potentials (57 recordings) from the subthalamic nucleus and substantia nigra pars reticulata of 30 patients with Parkinson's disease undergoing deep brain stimulation surgery. We found tone modulated and oddball modulated units in both regions. Population activity differentiated oddball from standard trials from 200 ms to 1000 ms after the tone in both regions. In the substantia nigra, beta band activity in the local field potential was decreased following oddball tones. The oddball related activity we observe may underlie attention, sensory prediction, or surprise-induced motor suppression.
Assuntos
Estimulação Acústica , Estimulação Encefálica Profunda , Doença de Parkinson , Parte Reticular da Substância Negra , Núcleo Subtalâmico , Humanos , Núcleo Subtalâmico/fisiologia , Masculino , Pessoa de Meia-Idade , Feminino , Doença de Parkinson/fisiopatologia , Doença de Parkinson/terapia , Idoso , Parte Reticular da Substância Negra/fisiologia , Estimulação Encefálica Profunda/métodos , Estimulação Acústica/métodos , Percepção Auditiva/fisiologia , Potenciais Evocados Auditivos/fisiologia , Substância Negra/fisiologia , AdultoRESUMO
External sensory cues can reduce freezing of gait in people with Parkinson's disease (PD), yet the role of the basal ganglia in these movements is unclear. We used microelectrode recordings to examine modulations in single unit (SU) and oscillatory local field potentials (LFP) during auditory-cued rhythmic pedaling movements of the feet. We tested five blocks of increasing cue frequencies (1 Hz, 1.5 Hz, 2 Hz, 2.5 Hz, and 3 Hz) in 24 people with PD undergoing deep brain stimulation surgery of the subthalamic nucleus (STN) or globus pallidus internus (GPi). Single unit firing and beta band LFPs (13-30 Hz) in response to movement onsets or cue onsets were examined. We found that the timing accuracy of foot pedaling decreased with faster cue frequencies. Increasing cue frequencies also attenuated firing rates in both STN and GPi neurons. Peak beta power in the GPi and STN showed different responses to the task. GPi beta power showed persistent suppression with fast cues and phasic modulation with slow cues. STN beta power showed enhanced beta synchronization following movement. STN beta power also correlated with rate of pedaling. Overall, we showed task-related responses in the GPi and STN during auditory-cued movements with differential roles in sensory and motor control. The results suggest a role for both input and output basal ganglia nuclei in auditory rhythmic pacing of gait-like movements in PD.
Assuntos
Estimulação Encefálica Profunda , Transtornos Neurológicos da Marcha , Doença de Parkinson , Núcleo Subtalâmico , Humanos , Doença de Parkinson/terapia , Globo Pálido/fisiologia , Sinais (Psicologia) , Núcleo Subtalâmico/fisiologia , Neurônios/fisiologia , Estimulação Encefálica Profunda/métodosRESUMO
BACKGROUND: Low-intensity transcranial ultrasound stimulation (TUS) is a noninvasive brain stimulation (NIBS) technique with high spatial specificity. Previous studies showed that TUS delivered in a theta burst pattern (tbTUS) increased motor cortex (MI) excitability up to 30 minutes due to long-term potentiation (LTP)-like plasticity. Studies using other forms of NIBS suggested that cortical plasticity may be impaired in patients with Parkinson's disease (PD). OBJECTIVE: The aim was to investigate the neurophysiological effects of tbTUS in PD patients off and on dopaminergic medications compared to healthy controls. METHODS: We studied 20 moderately affected PD patients in on and off dopaminergic medication states (7 with and 13 without dyskinesia) and 17 age-matched healthy controls in a case-controlled study. tbTUS was applied for 80 seconds to the MI. Motor-evoked potentials (MEP), short-interval intracortical inhibition (SICI), and short-interval intracortical facilitation (SICF) were recorded at baseline, and at 5 minutes (T5), T30, and T60 after tbTUS. Motor Unified Parkinson's Disease Rating Scale (mUPDRS) was measured at baseline and T60. RESULTS: tbTUS significantly increased MEP amplitude at T30 compared to baseline in controls and in PD patients on but not in PD patients off medications. SICI was reduced in PD off medications compared to controls. tbTUS did not change in SICI or SICF. The bradykinesia subscore of mUPDRS was reduced at T60 compared to baseline in PD on but not in the off medication state. The presence of dyskinesia did not affect tbTUS-induced plasticity. CONCLUSIONS: tbTUS-induced LTP plasticity is impaired in PD patients off medications and is restored by dopaminergic medications. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
RESUMO
BACKGROUND: There remains high variability in clinical outcomes when the same magnetic resonance image-guided focused ultrasound (MRgFUS) thalamotomy target is used for both essential tremor (ET) and tremor-dominant Parkinson's disease (TDPD). OBJECTIVE: Our goal is to refine the MRgFUS thalamotomy target for TDPD versus ET. METHODS: We retrospectively performed voxel-wise efficacy and structural connectivity mapping using 3-12-month post-procedure hand tremor scores for a multicenter cohort of 32 TDPD patients and a previously published cohort of 79 ET patients, and 24-hour T1-weighted post-MRgFUS brain images. We validated our findings using Unified Parkinson's Disease Rating Scale part III scores for an independent cohort of nine TDPD patients. RESULTS: The post-MRgFUS clinical improvements were 45.9% ± 35.9%, 55.5% ± 36%, and 46.1% ± 18.6% for ET, multicenter TDPD and validation TDPD cohorts, respectively. The TDPD and ET efficacy maps differed significantly (ppermute < 0.05), with peak TDPD improvement (87%) at x = -13.5; y = -15.0; z = 1.5, ~3.5 mm anterior and 3 mm dorsal to the ET target. Discriminative connectivity projections were to the motor and premotor regions in TDPD, and to the motor and somatosensory regions in ET. The disorder-specific voxel-wise efficacy map could be used to estimate outcome in TDPD patients with high accuracy (R = 0.8; R2 = 0.64; P < 0.0001). The model was validated using the independent cohort of nine TDPD patients (R = 0.73; R2 = 0.53; P = 0.025-voxel analysis). CONCLUSION: We demonstrated that the most effective MRgFUS thalamotomy target in TDPD is in the ventral intermediate nucleus/ventralis oralis posterior border region. This finding offers new insights into the thalamic regions instrumental in tremor control, with pivotal implications for improving treatment outcomes. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
RESUMO
INTRODUCTION: Aggressive disorders, in patients with intellectual disability, are satisfactorily managed with an educational, psychological, and pharmacological approach. Posterior hypothalamic region deep brain stimulation emerged in the last two decades as a promising treatment for patients with severe aggressive disorders. However, limited experiences are reported in the literature. METHODS: A systematic review was performed following PRISMA guidelines and recommendations by querying PubMed and Embase on August 24th, 2022, with the ensuing string parameters: ([deep brain stimulation] OR [DBS]) AND ([aggressiv*] OR disruptive). Cochrane Library, DynaMed, and ClinicalTrials.gov were consulted using the combination of keywords "deep brain stimulation" and "aggressive" or "aggression". The clinical outcome at the last follow-up and the rate of complications were considered primary and secondary outcomes of interest. RESULTS: The initial search identified 1,080 records, but only 10 studies met the inclusion criteria and were considered. The analysis of clinical outcome and complications was therefore performed on a total of 60 patients. Quality of all selected studies was classified as high, but one. Mean Overt Aggression Scale (OAS) improvement was 68%, while Inventory for Client Agency Planning (ICAP) improvement ranged between 38.3% and 80%. Complications occurred in 4 patients (6.7%). CONCLUSION: Posterior hypothalamic region deep brain stimulation may be considered a valuable option for patients with severe aggression disorders and ID. This review can represent a mainstay for those who will be engaged in the surgical treatment of these patients.
Assuntos
Agressão , Estimulação Encefálica Profunda , Deficiência Intelectual , Humanos , Estimulação Encefálica Profunda/métodos , Agressão/psicologia , Deficiência Intelectual/terapia , Hipotálamo Posterior , Resultado do TratamentoRESUMO
INTRODUCTION: Alzheimer's disease (AD) requires novel therapeutic approaches due to limited efficacy of current treatments. AREAS COVERED: This article explores AD as a manifestation of neurocircuit dysfunction and evaluates deep brain stimulation (DBS) as a potential intervention. Focusing on fornix-targeted stimulation (DBS-f), the article summarizes safety, feasibility, and outcomes observed in phase 1/2 trials, highlighting findings such as cognitive improvement, increased metabolism, and hippocampal growth. Topics for further study include optimization of electrode placement, and the role of stimulation-induced autobiographical-recall. Nucleus basalis of Meynert (DBS-NBM) DBS is also discussed and compared with DBS-f. Challenges with both DBS-f and DBS-NBM are identified, emphasizing the need for further research on optimal stimulation parameters. The article also reviews alternative DBS targets, including medial temporal lobe structures and the ventral capsule/ventral striatum. EXPERT OPINION: Looking ahead, a phase-3 DBS-f trial, and the prospect of closed-loop stimulation using EEG-derived biomarkers or hippocampal theta activity are highlighted. Recent FDA-approved therapies and other neuromodulation techniques like temporal interference and low-intensity ultrasound are considered. The article concludes by underscoring the importance of imaging-based diagnosis and staging to allow for circuit-targeted therapies, given the heterogeneity of AD and varied stages of neurocircuit dysfunction.
RESUMO
Non-invasive ultrasound neuromodulation has experienced exponential growth in the neuroscientific literature, recently also including clinical studies and applications. However, clinical recommendations for the secure and effective application of ultrasound neuromodulation in pathological brains are currently lacking. Here, clinical experts with neuroscientific expertise in clinical brain stimulation and ultrasound neuromodulation present initial clinical recommendations for ultrasound neuromodulation with relevance for all ultrasound neuromodulation techniques. The recommendations start with methodological safety issues focusing on technical issues to avoid harm to the brain. This is followed by clinical safety issues focusing on important factors concerning pathological situations.
Assuntos
Terapia por Ultrassom , Humanos , Terapia por Ultrassom/métodos , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagemRESUMO
Essential tremor DBS targeting the ventral intermediate nucleus (Vim) of the thalamus and its input, the dentato-rubro-thalamic tract (DRTt), has proven to be an effective treatment strategy. We examined thalamo-cortical evoked potentials (TCEPs) and cortical dynamics during stimulation of the DRTt. We recorded TCEPs in primary motor cortex during clinical and supra-clinical stimulation of the DRTt in ten essential tremor patients. Stimulation was varied over pulse amplitude (2-10 âmA) and pulse width (30-250 âµs) to allow for strength-duration testing. Testing at clinical levels (3 âmA, 60 âµs) for stimulation frequencies of 1-160 âHz was performed and phase amplitude coupling (PAC) of beta phase and gamma power was calculated. Primary motor cortex TCEPs displayed two responses: early and all-or-none (<20 âms) or delayed and charge-dependent (>50 âms). Strength-duration curve approximation indicates that the chronaxie of the neural elements related to the TCEPs is <200 âµs. At the range of clinical stimulation (amplitude 2-5 âmA, pulse width 30-60 âµs), TCEPs were not noted over primary motor cortex. Decreased pathophysiological phase-amplitude coupling was seen above 70 âHz stimulation without changes in power spectra and below the threshold of TCEPs. Our findings demonstrate that DRTt stimulation within normal clinical bounds does not excite fibers directly connected with primary motor cortex but that supra-clinical stimulation can excite a direct axonal tract. Both clinical efficacy and phase-amplitude coupling were frequency-dependent, favoring a synaptic filtering model as a possible mechanism of action.
Assuntos
Estimulação Encefálica Profunda , Tremor Essencial , Humanos , Tremor Essencial/terapia , Vias Neurais , Tálamo , Potenciais EvocadosRESUMO
Over the past 30 years, the field of neuromodulation has witnessed remarkable advancements. These developments encompass a spectrum of techniques, both non-invasive and invasive, that possess the ability to both probe and influence the central nervous system. In many cases neuromodulation therapies have been adopted into standard care treatments. Transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and transcranial ultrasound stimulation (TUS) are the most common non-invasive methods in use today. Deep brain stimulation (DBS), spinal cord stimulation (SCS), and vagus nerve stimulation (VNS), are leading surgical methods for neuromodulation. Ongoing active clinical trials using are uncovering novel applications and paradigms for these interventions.
Assuntos
Estimulação Encefálica Profunda , Estimulação Transcraniana por Corrente Contínua , Estimulação Magnética Transcraniana , Humanos , Estimulação Encefálica Profunda/métodos , Estimulação Magnética Transcraniana/métodos , Estimulação Transcraniana por Corrente Contínua/métodos , Estimulação da Medula Espinal/métodos , Estimulação do Nervo Vago/métodos , Estimulação do Nervo Vago/tendênciasRESUMO
INTRODUCTION: Essential tremor (ET) is the most frequent movement disorder, affecting up to 5% of adults > 65 years old. In 30-50% of cases, optimal medical management provides insufficient tremor relief and surgical options are considered. Thalamotomy is a time-honored intervention, which can be performed using radiofrequency (RF), stereotactic radiosurgery (SRS), or magnetic resonance-guided focused ultrasounds (MRgFUS). While the latter has received considerable attention in the last decade, SRS has consistently been demonstrated as an effective and well-tolerated option. AREAS COVERED: This review discusses the evidence on SRS thalamotomy for ET. Modern workflows and emerging techniques are detailed. Current outcomes are analyzed, with a specific focus on tremor reduction, complications and radiological evolution of the lesions. Challenges for the field are highlighted. EXPERT OPINION: SRS thalamotomy improves tremor in > 80% patients. The efficacy appears comparable to other modalities, including DBS, RF and MRgFUS. Side effects result mostly from idiosyncratic hyper-responses to radiation, which occur in up to 10% of treatments, are usually self-resolving, and are symptomatic in < 4% of patients. Future research should focus on accumulating more data on bilateral treatments, collecting long-term outcomes, refining targeting, and improving lesion consistency.
Assuntos
Tremor Essencial , Radiocirurgia , Tálamo , Tremor Essencial/cirurgia , Tremor Essencial/terapia , Humanos , Radiocirurgia/métodos , Radiocirurgia/tendências , Tálamo/cirurgiaRESUMO
OBJECTIVE: Deep brain stimulation (DBS) is an effective treatment for medically refractory movement disorders and other neurological conditions. To comprehensively characterize the prevalence, locations, timing of detection, clinical effects, and risk factors of DBS-related intracranial hemorrhage (ICH), the authors performed a systematic review of the published literature. METHODS: PubMed, EMBASE, and Web of Science were searched using 2 concepts: cerebral hemorrhage and brain stimulation, with filters for English, human studies, and publication dates 1980-2023. The inclusion criteria were the use of DBS intervention for any human neurological condition, with documentation of hemorrhagic complications by location and clinical effect. Studies with non-DBS interventions, no documentation of hemorrhage outcome, patient cohorts of ≤ 10, and pediatric patients were excluded. The risk of bias was assessed using Centre for Evidence-Based Medicine Levels of Evidence. The authors performed proportional meta-analysis for ICH prevalence. RESULTS: A total of 63 studies, with 13,056 patients, met the inclusion criteria. The prevalence of ICH was 2.9% (fixed-effects model, 95% CI 2.62%-3.2%) per patient and 1.6% (random-effects model, 95% CI 1.34%-1.87%) per DBS lead, with 49.6% being symptomatic. The ICH rates did not change with time. ICH most commonly occurred around the DBS lead, with 16% at the entry point, 31% along the track, and 7% at the target. Microelectrode recording (MER) during DBS was associated with increased ICH rate compared to DBS without MER (3.5 ± 2.2 vs 2.1 ± 1.4; p[T ≤ t] 1-tail = 0.038). Other reported ICH risk factors include intraoperative systolic blood pressure > 140 mm Hg, sulcal DBS trajectories, and multiple microelectrode insertions. Sixty percent of ICH was detected at 24 hours postoperatively and 27% intraoperatively. The all-cause mortality rate of DBS was 0.4%, with ICH accounting for 22% of deaths. Single-surgeon DBS experience showed a weak inverse correlation (r = -0.27, p = 0.2189) between the rate of ICH per lead and the number of leads implanted per year. CONCLUSIONS: This study provides level III evidence that MER during DBS is a risk factor for ICH. Other risk factors include intraoperative systolic blood pressure > 140 mm Hg, sulcal trajectories, and multiple microelectrode insertions. Avoidance of these risk factors may decrease the rate of ICH.
Assuntos
Estimulação Encefálica Profunda , Hemorragias Intracranianas , Estimulação Encefálica Profunda/efeitos adversos , Humanos , Hemorragias Intracranianas/epidemiologia , Hemorragias Intracranianas/etiologia , Fatores de Risco , PrevalênciaRESUMO
Diffusion-weighted MRI (dMRI) is a widely used neuroimaging modality that permits the in vivo exploration of white matter connections in the human brain. Normative structural connectomics - the application of large-scale, group-derived dMRI datasets to out-of-sample cohorts - have increasingly been leveraged to study the network correlates of focal brain interventions, insults, and other regions-of-interest (ROIs). Here, we provide a normative, whole-brain connectome in MNI space that enables researchers to interrogate fiber streamlines that are likely perturbed by given ROIs, even in the absence of subject-specific dMRI data. Assembled from multi-shell dMRI data of 985 healthy Human Connectome Project subjects using generalized Q-sampling imaging and multispectral normalization techniques, this connectome comprises ~12 million unique streamlines, the largest to date. It has already been utilized in at least 18 peer-reviewed publications, most frequently in the context of neuromodulatory interventions like deep brain stimulation and focused ultrasound. Now publicly available, this connectome will constitute a useful tool for understanding the wider impact of focal brain perturbations on white matter architecture going forward.
Assuntos
Conectoma , Substância Branca , Humanos , Encéfalo/diagnóstico por imagem , Conectoma/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Neuroimagem , Substância Branca/diagnóstico por imagemRESUMO
BACKGROUND: Deep brain stimulation (DBS) has been widely used to manage debilitating neurological symptoms in movement disorders such as Parkinson's disease (PD). Despite its well-established symptomatic benefits, our understanding of the mechanisms underlying DBS and its possible effect on the accumulation of pathological proteins in neurodegeneration remains limited. Accumulation and oligomerization of the protein alpha-synuclein (α-Syn) are implicated in the loss of dopaminergic neurons in the substantia nigra in PD, making α-Syn a potential therapeutic target for disease modification. OBJECTIVE: We examined the effects of high frequency electrical stimulation on α-Syn levels and oligomerization in cell and rodent models. METHODS: High frequency stimulation, mimicking DBS parameters used for PD, was combined with viral-mediated overexpression of α-Syn in cultured rat primary cortical neurons or in substantia nigra of rats. Bimolecular protein complementation with split fluorescent protein reporters was used to detect and quantify α-Syn oligomers. RESULTS: High frequency electrical stimulation reduced the expression of PD-associated mutant α-Syn and mitigated α-Syn oligomerization in cultured neurons. Furthermore, DBS in the substantia nigra, but not the subthalamic nucleus, decreased overall levels of α-Syn, including oligomer levels, in the substantia nigra. CONCLUSIONS: Taken together, our results demonstrate that direct high frequency stimulation can reduce accumulation and pathological forms of α-Syn in cultured neurons in vitro and in substantia nigra in vivo. Thus, DBS therapy could have a role beyond symptomatic treatment, with potential disease-modifying properties that can be exploited to target pathological proteins in neurodegenerative diseases.
Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , alfa-Sinucleína , Animais , alfa-Sinucleína/metabolismo , alfa-Sinucleína/genética , Estimulação Encefálica Profunda/métodos , Ratos , Doença de Parkinson/terapia , Doença de Parkinson/metabolismo , Ratos Sprague-Dawley , Modelos Animais de Doenças , Substância Negra/metabolismo , Células Cultivadas , Masculino , Neurônios/metabolismo , Neurônios/fisiologia , Estimulação Elétrica/métodosRESUMO
BACKGROUND: Information transmission into the human nervous system is the basis for a variety of prosthetic applications. Spinal cord stimulation (SCS) systems are widely available, have a well documented safety record, can be implanted minimally invasively, and are known to stimulate afferent pathways. Nonetheless, SCS devices are not yet used for computer-brain-interfacing applications. OBJECTIVE: Here we aimed to establish computer-to-brain communication via medical SCS implants in a group of 20 individuals who had been operated for the treatment of chronic neuropathic pain. METHODS: In the initial phase, we conducted interface calibration with the aim of determining personalized stimulation settings that yielded distinct and reproducible sensations. These settings were subsequently utilized to generate inputs for a range of behavioral tasks. We evaluated the required calibration time, task training duration, and the subsequent performance in each task. RESULTS: We could establish a stable spinal computer-brain interface in 18 of the 20 participants. Each of the 18 then performed one or more of the following tasks: A rhythm-discrimination task (n = 13), a Morse-decoding task (n = 3), and/or two different balance/body-posture tasks (n = 18; n = 5). The median calibration time was 79 min. The median training time for learning to use the interface in a subsequent task was 1:40 min. In each task, every participant demonstrated successful performance, surpassing chance levels. CONCLUSION: The results constitute the first proof-of-concept of a general purpose computer-brain interface paradigm that could be deployed on present-day medical SCS platforms.
Assuntos
Interfaces Cérebro-Computador , Humanos , Encéfalo , ComputadoresRESUMO
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) produces an electrophysiological signature called evoked resonant neural activity (ERNA); a high-frequency oscillation that has been linked to treatment efficacy. However, the single-neuron and synaptic bases of ERNA are unsubstantiated. This study proposes that ERNA is a subcortical neuronal circuit signature of DBS-mediated engagement of the basal ganglia indirect pathway network. In people with Parkinson's disease, we: (i) showed that each peak of the ERNA waveform is associated with temporally-locked neuronal inhibition in the STN; (ii) characterized the temporal dynamics of ERNA; (iii) identified a putative mesocircuit architecture, embedded with empirically-derived synaptic dynamics, that is necessary for the emergence of ERNA in silico; (iv) localized ERNA to the dorsal STN in electrophysiological and normative anatomical space; (v) used patient-wise hotspot locations to assess spatial relevance of ERNA with respect to DBS outcome; and (vi) characterized the local fiber activation profile associated with the derived group-level ERNA hotspot.
Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , Núcleo Subtalâmico , Humanos , Doença de Parkinson/terapia , Estimulação Encefálica Profunda/métodos , Núcleo Subtalâmico/fisiologia , Gânglios da Base/fisiologia , Neurônios/fisiologiaRESUMO
BACKGROUND: A randomized trial suggested that reducing left-sided subthalamic stimulation amplitude could improve axial dysfunction. OBJECTIVES: To explore open-label tolerability and associations between trial outcomes and asymmetry data. METHODS: We collected adverse events in trial participants treated with open-label lateralized settings for ≥3 months. We explored associations between trial outcomes, location of stimulation and motor asymmetry. RESULTS: 14/17 participants tolerated unilateral amplitude reduction (left-sided = 10, right-sided = 4). Two hundred eighty-four left-sided and 1113 right-sided stimulated voxels were associated with faster gait velocity, 81 left-sided and 22 right-sided stimulated voxels were associated with slower gait velocity. Amplitude reduction contralateral to shorter step length was associated with 2.4-point reduction in axial MDS-UPDRS. Reduction contralateral to longer step length was associated with 10-point increase in MDS-UPDRS. CONCLUSIONS: Left-sided amplitude reduction is potentially more tolerable than right-sided amplitude reduction. Right-sided more than left-sided stimulation could be associated with faster gait velocity. Shortened step length might reflect contralateral overstimulation.
RESUMO
Osteoarthritis causes progressive joint deterioration, severe morbidity, and reduced mobility in both humans and horses. Currently, osteoarthritis is diagnosed at late stages through clinical examination and radiographic imaging, hence it is challenging to address and provide timely therapeutic interventions to slow disease progression or ameliorate symptoms. Extracellular vesicles are cell-derived vesicles that play a key role in cell-to-cell communication and are potential sources for specific composite biomarker panel discovery. We here used a multi-omics strategy combining proteomics and phospholipidomics in an integral approach to identify composite biomarkers associated to purified extracellular vesicles from synovial fluid of healthy, mildly and severely osteoarthritic equine joints. Although the number of extracellular vesicles was unaffected by osteoarthritis, proteome profiling of extracellular vesicles by mass spectrometry identified 40 differentially expressed proteins (non-adjusted p < 0.05) in osteoarthritic joints associated with 7 significant canonical pathways in osteoarthritis. Moreover, pathway analysis unveiled changes in disease and molecular functions during osteoarthritis development. Phospholipidome profiling by mass spectrometry showed a relative increase in sphingomyelin and a decrease in phosphatidylcholine, phosphatidylinositol, and phosphatidylserine in extracellular vesicles derived from osteoarthritic joints compared to healthy joints. Unsupervised data integration revealed positive correlations between the proteome and the phospholipidome. Comprehensive analysis showed that some phospholipids and their related proteins increased as the severity of osteoarthritis progressed, while others decreased or remained stable. Altogether our data show interrelationships between synovial fluid extracellular vesicle-associated phospholipids and proteins responding to osteoarthritis pathology and which could be explored as potential composite diagnostic biomarkers of disease.
RESUMO
Spatial normalization-the process of mapping subject brain images to an average template brain-has evolved over the last 20+ years into a reliable method that facilitates the comparison of brain imaging results across patients, centers & modalities. While overall successful, sometimes, this automatic process yields suboptimal results, especially when dealing with brains with extensive neurodegeneration and atrophy patterns, or when high accuracy in specific regions is needed. Here we introduce WarpDrive, a novel tool for manual refinements of image alignment after automated registration. We show that the tool applied in a cohort of patients with Alzheimer's disease who underwent deep brain stimulation surgery helps create more accurate representations of the data as well as meaningful models to explain patient outcomes. The tool is built to handle any type of 3D imaging data, also allowing refinements in high-resolution imaging, including histology and multiple modalities to precisely aggregate multiple data sources together.