SEARCH · PubMed Health

Results for “Deep Brain Stimulation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources

PubMed2006

Saccade-related potentials recorded from human subthalamic nucleus.

OBJECTIVE: To investigate an ocular motor role for the STN in Parkinson's disease (PD) patients. METHODS: Potentials were recorded from deep brain stimulation (DBS) electrodes implanted in the vicinity of STN in five PD patients, while patients simultaneously performed visually cued saccades, self-paced saccades and in two patients self-paced wrist extensions. RESULTS: Premovement potentials related to visually cued saccades were found in 4/5 patients and 56% (5/9) of potentials showed phase reversal indicating a local generator. Onsets of these potentials began closer to saccade initiation from STN contacts (0.88+/-0.30s) than thalamic ones (1.39+/-0.28 s). Self-paced saccade-related potentials were found in 4/4 patients. Self-paced saccade potential onsets (1.82+/-0.88 s) were not different from self-paced wrist extension onsets (1.27+/-0.98 s), suggesting a non-specific mechanism could be responsible for both potentials. 50% (3/6) of potentials to self-paced saccades and 66% (2/3) of potentials to self-paced wrist extensions showed phase reversal. Potentials could be found either ipsilaterally or contralaterally with respect to saccade direction. CONCLUSIONS: These subcortical premovement potentials to saccades are similar to Bereitschaftspotentials and contingent negative variations to limb movements recorded in cortical and subcortical regions. SIGNIFICANCE: These studies further support a role of STN in ocular motor control and suggest a common mechanism of motor preparation for both eye and limb movements in the basal ganglia.

Adult↗

PubMed2005

Intra-operative STN DBS attenuates the prominent beta rhythm in the STN in Parkinson's disease.

Power spectra from local field potentials (LFPs) recorded post-operatively from the deep brain stimulation (DBS) macroelectrode show prominence of the beta rhythm (11-30 Hz) in untreated Parkinson's disease (PD). Dopaminergic medication and movement attenuate this beta band in PD. In this pilot study of six sides in four patients, we recorded LFPs from the DBS electrode in untreated PD patients in the operating room. In all cases, there was a peak in the time-frequency spectrogram in the beta frequency range when the patients were at rest, which was associated with attenuation in the same range with movement. The actual frequency range and the strength of the beta peak varied among cases. In two patients, intra-operative constraints permitted recording of LFPs at rest, before and immediately after subthalamic nucleus (STN) DBS. In both patients we documented that STN DBS caused a significant attenuation in power in the beta band at rest that persisted for 15-25 s after DBS had been turned off (P < 0.01). From one case, our data suggest that the beta rhythm attenuation was most prominent within the STN itself. This study shows for the first time that STN DBS attenuates the power in the prominent beta band recorded in the STN of patients with PD. These pilot findings raise the interesting possibility of using this biomarker for closed loop DBS or neuromodulation.

Beta Rhythm↗

PubMed2006

Uniform qualitative electrophysiological changes in postoperative rest tremor.

Ablation and deep brain stimulation (DBS) can treat pharmacologically uncontrollable tremor. Here, we compared the postoperative electrophysiological changes in resting hand tremor after 32 ablations and 12 DBS implantations in patients with severe tremor-dominant idiopathic Parkinson's disease (PD) and essential tremor (ET). Short- and long-term accelerometric data were acquired after surgery and were compared to the preoperative tremor. After effective surgical treatments, significant rest tremor reduction and increase in both frequency and approximate entropy (ApEn) were detected in all PD cases, irrespective of the type and target of intervention. However, the long-term effect of DBS implantation on tremor reduction was significantly better compared to that after ablative treatments. In cases of thalamotomy, the postoperative increase in frequency and ApEn was significantly larger in essential tremor compared to PD, suggesting that the etiology of tremor may influence the size of the similar changes. However, cases where clinical tremor re-emerged 6 to 12 months after the surgery, no change in frequency and ApEn was detected on the second postoperative day, despite an initial tremor reduction and clinical improvement similar to the effective operations. Our results suggest that uniform postoperative changes in rest tremor and the increase in frequency and ApEn could be due to attenuation of pathological oscillators and might be immediate indicators of the effectiveness of neurosurgical treatments relieving tremor.

Cautery↗

PubMed2005

Movement-related changes in oscillatory activity in the human subthalamic nucleus: ipsilateral vs. contralateral movements.

A voluntary movement is accompanied by a series of changes in neuronal oscillatory activity in the subthalamic nucleus (STN). These changes can be recorded through electrodes implanted for deep brain stimulation to treat Parkinson's disease in the time interval between the surgery and the internalization of the connections to the batteries. Both baseline activity and movement-related changes are different in the 'on' and 'off' medication motor states. In the 'off' state a low frequency activity in the alpha-beta range (8-25 Hz) that dominates the spectrum is interrupted during the movement, while in the 'on' state baseline frequencies are higher and a peri-movement gamma increase (70-80 Hz) is usually observed. Similar changes have been described with electrocorticographic recordings over the primary motor cortex but the gamma increase was only present during contralateral movements. We compared ipsi- and contralateral movement-related changes in STN activity, using a time-frequency analysis of the recordings obtained simultaneously in both STN and the scalp (electroencephalography) during right and left hand movements. The movement-related changes observed in the STN in the 'on' and the 'off' states were similar to those described previously in terms of predominant frequency bands, but we found bilateral changes in the STN during movements of either hand. A contralateral earlier start of the beta STN changes was mostly observed when the moving hand corresponded to the less-affected side, irrespective of hand dominance. These results suggest that movement-related activity in the STN has, by and large, a bilateral representation and probably reflects cortical input.

Aged↗

PubMed2006

The physiologically modulated electrode potentials at the depth electrode-brain interface in humans.

To study the modulated electrical potential specifically related to the electrode-brain interface (EBI) in deep brain stimulation (DBS) under physiological condition, we quantitatively identified the physiologically modulated electrode potentials by decomposing the local field potentials (LFPs) recorded from 11 patients (18 electrodes in four different brain regions) who underwent DBS, and correlated them with simultaneously recorded physiological signals of blood pressure (BP) and respiration. Results showed that electrode potentials were modulated by BP and respiration and could be detected as a specific component of the compound LFP signals with a mean (+/-S.D.) amplitude of 6.9+/-1.7 microV. The detection rate and amplitude of the modulated electrode potentials were independent from brain regions and neurological disorders. The current approach can be used to study the changes in properties of the EBI under physiological condition and to investigate the effects of the EBI on the 'crossing' current of either the neural signals to be recorded or the electrical pulses for neurostimulation.

Blood Pressure↗

PubMed2005

Accuracy of customized miniature stereotactic platforms.

In this study, a new system was evaluated for implanting deep-brain stimulators based on a one-piece platform for each trajectory customized from a preoperative planning image. During surgery, the platform is attached to skull-implanted posts that extend through the scalp. The platform acts as a miniature stereotactic frame to provide guidance for parallel cannulas as they are advanced through a burr hole to the target. Accuracy is determined from a postoperative CT. For each implantation, the distance between the position observed in the postoperative image and the position calculated relative to the platform from the preoperative image is our measure of error. Because this measure incorporates the surgical error of electrode anchoring, brain shift between preoperative and postoperative scanning, and error in the measurement of the position of the electrode in CT, it will tend to overestimate the true error. The mean error was 2.8 mm for 20 implantations. These data reflect favorably the accuracy of this system when compared with others.

Artifacts↗

PubMed2006

Functional imaging of sequence learning in Parkinson's disease.

Sequence learning, a cognitive task linked to cortico-striatal function, is impaired in Parkinson's disease (PD). We chose this task as a behavioral paradigm to study the functional architecture of PD in treated and untreated conditions. In our studies, participants were scanned with H(2)(15)O while performing a kinematically controlled motor sequence learning task and a matching motor baseline task. Experiments revealed that a specific sequence learning network predicts learning in normal subjects, and in independent cohorts of early and advanced PD patients. The analysis of the relationship of network activity to learning performance revealed diverging influences of dopaminergic therapy and deep brain stimulation (DBS). DBS of the internal GP and of STN increased network activity and task performance, while levodopa decreased both measures. In separate studies, we investigated the role of dopaminergic modulation on brain activation during sequence learning. In healthy subjects dopamine transporter (DAT) binding correlated with learning-related brain activation in prefrontal, premotor and cingulate cortices, and in the thalamus. By contrast, in PD most of these regional relationships were lost. Only ventral and dorsolateral prefrontal cortex activation correlated with caudate dopaminergic input. In a final set of studies, we found a significant decline in learning performance in early stage PD patients followed over the course of 2 years. Longitudinal declines in learning-related activation were found in parietal areas, while concomitant increases were localized to the left hippocampus. These observations support hypotheses on disease-stage and task-specific effects within the different cortico-striato-pallido-thalamocortical loops and the mesocortical system in PD.

Aged↗

PubMed2004

Eye movement-related responses of neurons in human subthalamic nucleus.

Intraoperative microelectrode single unit recordings are routinely made in the subthalamic nucleus (STN) of awake and alert Parkinson's disease (PD) patients during surgery for implantation of deep brain stimulation (DBS) electrodes. These recordings not only assist in determining the optimal target for electrode implantation, but also offer the unique opportunity to study movement-evoked responses from the basal ganglia. We report on the responses of human STN neurons to eye movements from eight PD patients (five men and three women). Twenty percent (18/89) of tested STN neurons showed responses to eye movements. Patients made pro-saccades, voluntary saccades or smooth pursuit eye movements in four directions: up, down, left, right. The majority of STN neurons (72% or 13/18), that responded to eye movements were found in the ventral half of the nucleus, while 58% (22/38) of STN neurons that had somatic responses were found in the dorsal half of the nucleus. The firing rate for STN oculomotor neurons was 33+/-15 Hz (n = 18), which was not different from that reported previously for STN neurons. Most neurons only responded to eye movements in a single direction, but 17% (3/18) showed responses to more than one direction. The majority of responses (17/18) to eye movements were increases in firing rate although one neuron did show a pause in firing with eye movement onset. The phasic changes in firing rate in response to eye movement usually occurred up to 250 ms following eye movement onset. Neurons were found that showed task-specific responses to cued versus self-paced saccades, responded to both passive limb movement and voluntary eye movement, and appeared to show either visual or attentional responses. These human physiological data, in conjunction with previous anatomical studies, suggest that the STN might have an oculomotor role. Although there is no evidence that STN is responsible for driving eye movements, it may have a role in either sensory feedback, corollary discharge, or in focusing the substantia nigra pars reticulata to allow a saccade to occur through disinhibition of the superior colliculus.

Action Potentials↗

PubMed2005

Automatic selection of DBS target points using multiple electrophysiological atlases.

In this paper we study and evaluate the influence of the choice of a particular reference volume as the electrophysiological atlas on the accuracy of the automatic predictions of optimal points for deep brain stimulator (DBS) implants. We refer to an electrophysiological atlas as a spatial map of electrophysiological information such as micro electrode recordings (MER), stimulation parameters, final implants positions, etc., which are acquired for each patient and then mapped onto a single reference volume using registration algorithms. An atlas-based prediction of the optimal point for a DBS surgery is made by registering a patient's image volume to that reference volume, that is, by computing a correct coordinate mapping between the two; and then by projecting the optimal point from the atlas to the patient using the transformation from the registration algorithm. Different atlases, as well as different parameterizations of the registration algorithm, lead to different and somewhat independent atlas-based predictions. We show how the use of multiple reference volumes can improve the accuracy of prediction by combining the predictions from the multiple reference volumes weighted by the accuracy of the non-rigid registration between each of the corresponding atlases and the patient volume.

Brain Mapping↗

PubMed2006

Abnormal metabolic network activity in Parkinson's disease: test-retest reproducibility.

Parkinson's disease (PD) is associated with an abnormal pattern of regional brain function. The expression of this PD-related covariance pattern (PDRP) has been used to assess disease progression and the response to treatment. In this study, we validated the PDRP network as a measure of parkinsonism by prospectively computing its expression (PDRP scores) in (15)O-water (H(2)(15)O) and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scans from PD patients and healthy volunteers. The reliability of this measure was also assessed within subjects using a test-retest design in mildly affected and advanced PD patients scanned at baseline and during treatment with levodopa or deep brain stimulation (DBS). We found that PDRP expression was significantly elevated in PD patients (P<0.001) relative to controls in a prospective analysis of brain scans obtained with either H(2)(15)O or FDG PET. A significant correlation (R(2)=0.61; P<0.001) was evident between PDRP scores computed from H(2)(15)O and FDG images in PD subjects scanned with both tracers. Test-retest reproducibility was very high (intraclass correlation coefficient (ICC)>0.92) for PDRP scores measured both within PET session and between sessions separated by up to 2 months. This high reproducibility was observed in both early stage and advanced PD patients scanned at baseline and during treatment. The within-subject variability of this measure was less than 10% for both unmedicated and treated conditions. These findings suggest that the PDRP network is a reproducible and stable descriptor of regional functional abnormalities in parkinsonism. The quantification of PDRP expression in PD patients can serve as a potential biomarker in PET intervention studies for this disorder.

Aged↗

PubMed2006

Mental chronometry of target detection: human thalamus leads cortex.

Attentive monitoring of environmental stimuli is most fundamental for rapid target detection. The aim of this study was to assess the timing of thalamic versus cortical processes involved in this cognitive operation. To this end, simultaneous depth and scalp EEG was recorded in eight patients with essential tremor, undergoing thalamic deep brain stimulation (DBS), when the DBS electrodes could be accessed via their temporarily externalized leads. The patients performed an oddball task consisting of 300 presentations of one frequent and two rare visual cues, appearing in randomized order. One of the rare cues was defined as a target, the occurrences of which had to be indicated by a button press (motor condition) or silently counted (non-motor condition). At the scalp and the thalamus, event-related potentials (ERP) were largest upon target presentation, with peak latencies in the time domain of classical P300 responses. Remarkably, target-specific thalamic ERP emerged significantly prior to scalp P300. Furthermore, whereas scalp ERP had a higher amplitude upon rare than upon frequent non-target signals, thalamic ERP were independent of stimulus probability. This pattern was identified during motor and non-motor task execution. We conclude that the human thalamus specifically supports the early recognition of target events and can widely distribute this label through its divergent cortical projections.

Adult↗

PubMed2006

Real-time refinement of subthalamic nucleus targeting using Bayesian decision-making on the root mean square measure.

The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.

Bayes Theorem↗

PubMed2004

Electron microscopy of tissue adherent to explanted electrodes in dystonia and Parkinson's disease.

Deep brain stimulation (DBS) is used to treat a variety of severe medically intractable movement disorders, including Parkinson's disease, tremor and dystonia. There have been few studies examining the effect of chronic DBS on the brains of Parkinson's disease patients. Most of these post mortem studies concluded that chronic DBS caused mild gliosis around the lead track and did not damage brain tissue. There have been no similar histopathological studies on brains from dystonic patients who have undergone DBS. In this study, our objective was to discover whether tissue would be attached to DBS electrodes removed from patients for routine clinical reasons. We hoped that by examining explanted DBS electrodes using scanning (SEM) and/or transmission (TEM) electron microscopy we might visualize any attached tissue and thus understand the electrode-human brain tissue interaction more accurately. Initially, SEM was performed on one control DBS electrode that had not been implanted. Then 21 (one subthalamic nucleus and 20 globus pallidus internus) explanted DBS electrodes were prepared, after fixation in 3% glutaraldehyde, for SEM (n = 9) or TEM (n = 10), or both (n = 2), according to departmental protocol. The electrodes were sourced from two patients with Parkinson's disease, one with myoclonic dystonia, two with cervical dystonia and five with primary generalized dystonia, and had been in situ for 11 and 31 months (Parkinson's disease), 16 months (myoclonic dystonia), 14 and 24 months (cervical dystonia) and 3-24 months (primary generalized dystonia). Our results showed that a foreign body multinucleate giant cell-type reaction was present in all TEM samples and in SEM samples, prewashed to remove surface blood and fibrin, regardless of the diagnosis. Some of the giant cells were >100 microm in diameter and might have originated from either fusion of parenchymal microglia, resident perivascular macrophage precursors and/or monocytes/macrophages invading from the blood stream. The presence of mononuclear macrophages containing lysosomes and sometimes having conspicuous filopodia was detected by TEM. Both types of cell contained highly electron-dense inclusions, which probably represent phagocytosed material. Similar material, the exact nature of which is unknown, was also seen in the vicinity of these cells. This reaction was present irrespective of the duration of implantation and may be a response to the polyurethane component of the electrodes' surface coat. These findings may be relevant to our understanding of the time course of the clinical response to DBS in Parkinson's disease and various forms of dystonia, as well as contributing to the design characteristics of future DBS electrodes.

Adult↗

PubMed1987

Thalamic stimulation effects on reactive depression.

Depression was evaluated in 10 patients before and after therapeutic mesothalamic brain stimulation for chronic pain. Minnesota multiphasic personality inventory T scores for depression were high in all patients before stimulation. Scores were decreased in 8 of 10 patients with chronic deep brain stimulation, three of whom returned to normal. Pain relief was good to excellent in 9 of 10 patients. It is concluded that depression is secondary to pain or pain-inducing factors which implicate the catecholamine and serotonergic systems.

Adjustment Disorders↗

PubMed2004

Bilateral globus pallidus stimulation for Huntington's disease.

Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) was performed in a patient with Huntington's disease (HD) with severe chorea. Stimulation at 40 and 130 Hz improved chorea. Stimulation at 130 Hz slightly worsened bradykinesia overall, whereas 40 Hz had little effect. A [15O] H2O positron emission tomography showed increased regional cerebral blood flow in motor decision making and execution areas more evident at 40 Hz. Adjustment of stimulation parameters in GPi DBS may have the potential to optimize the motor response in HD, improving chorea without aggravating bradykinesia.

Adult↗

PubMed2003

Acute psychotropic effects of bilateral subthalamic nucleus stimulation and levodopa in Parkinson's disease.

High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves the motor symptoms of Parkinson's disease (PD). Opposite changes in mood, such as mania or depression, have been reported after surgery, but it is not known whether these side effects are specifically related to STN DBS. To learn whether STN DBS also influences the limbic loop, we investigated acute subjective psychotropic effects related to levodopa or bilateral STN DBS. After a median postoperative follow-up of 12 months, 50 PD patients completed the Addiction Research Center Inventory (ARCI), assessing subjective psychotropic effects in four conditions: off-drug/on-stimulation; off-drug/off-stimulation; on-drug/off-stimulation; and on-drug/on-stimulation. Both levodopa and STN DBS improved all the ARCI subscales, indicating subjective feelings of well being, euphoria, increase in motivation, and decrease in fatigue, anxiety, and tension. A suprathreshold dose of levodopa was significantly more effective than STN DBS, using the same electrical parameters as for chronic stimulation, on four of the five ARCI subscales. We concluded that 1) both STN DBS and levodopa have synergistic acute beneficial psychotropic effects in PD, 2) the psychotropic effects of both treatments need to be considered in the long-term management of chronic STN DBS, and 3) the results indicate an involvement of the limbic STN in mood disorders of PD.

Activities of Daily Living↗

PubMed1981

[Addiction-like behavior with continuous self-stimulation of the mediothalamic system (author's transl)].

In a patient with postamputation pain a continuous self-stimulation of the mediothalamic system by a chronic deep brain electrode induced a change in behavior, similar to addiction. At the same time various psychological tests (HAWIE, Benton, Hooper-VOT and concentration tests) were significantly disturbed. After interruption of the deep brain stimulation all induced psychic abnormalities normalized within a few days.

Adult↗

PubMed2026

A systematic review of macaque brain stimulation: Trends and future directions.

Neurostimulation techniques can powerfully modulate neural circuit activity and provide causal insights into the relationship between brain function and behavior. Macaque monkeys have long been a key animal model for brain stimulation studies. While stimulating the macaque brain with one or a few electrodes has already taught us much about brain function and dysfunction, recent technological advances promise a future with more precise stimulation using many more electrodes. However, such possibilities also increase the number of choices an experimenter has when designing their study. We can learn from a rich past, but a comprehensive overview of which brain regions have been studied and with what stimulation parameters is lacking. Here, we present a PRISMA-compliant systematic review of 734 macaque brain stimulation studies using electrical and/or optogenetic stimulation. We find a striking bias in which brain areas have traditionally been stimulated: a mere 10 brain regions account for half of all studies, with the remainder of studies investigating approximately 150 other areas. Across studies, stimulation frequency robustly predicted direct behavioral effects independent of brain region, while amplitude did not. Future studies could more systematically explore less studied regions through lower stimulation frequencies (e.g., 20-50 Hz) alongside established ranges (∼200 Hz). Tools such as fMRI or optical imaging can capture neural circuit engagement evoked by these frequencies, even when behavioral effects are absent or remain subtle. Our synthesis offers a guide towards the next steps in high-channel-count, high-precision stimulation approaches.

Animals↗