Relationship between Neural Activation and Electric Field Distribution during Deep Brain Stimulation

Åström, Maria; Diczfalusy, Elin; Martens, H.C.F.; Wårdell, Karin

doi:10.1109/tbme.2014.2363494

Cited by 197 publications

(205 citation statements)

References 47 publications

Supporting

Mentioning

202

Contrasting

Order By: Relevance

“…Stimulation fields, henceforth referred to as volumes of neural activation (VNAs), were generated for all the assessed stimulation settings. Homogeneous tissue, straight long axons with diameters of 2.5 µm, together with the assessed stimulation settings (amplitude and pulse width), were used for the simulations of the VNAs as described in Åström et al [18]. PSMs where created for stimulation settings with excellent, good, and poor effect as defined in table 2.…”

Section: Methodsmentioning

confidence: 99%

Deep Brain Stimulation of the Caudal Zona Incerta: Tremor Control in Relation to the Location of Stimulation Fields

Fytagoridis

Åström

Samuelsson

et al. 2016

Stereotact Funct Neurosurg

View full text Add to dashboard Cite

Background: The caudal zona incerta (cZi) and posterior subthalamic area (PSA) are an emerging deep brain stimulation (DBS) target for essential tremor (ET). Objectives: To evaluate the efficacy of tremor control in relation to the anatomical locations of stimulation fields in 50 patients with ET and DBS of the cZi. Methods: A total of 240 contacts were evaluated separately with monopolar stimulation, and amplitudes were optimized for improvement of tremor and hand function. Stimulation fields, i.e., volumes of neural activation, were simulated for each optimized setting and assembled into probabilistic stimulation maps (PSMs). Results: There were differences in the anatomical distribution of PSMs associated with good versus poor tremor control. The location of PSMs which achieved good and excellent tremor control corresponded well with the PSM for the clinically used settings, and they were located within the superior part of the PSA. Conclusions: PSMs may serve as a useful tool for defining the most efficacious anatomical location of stimulation. The best tremor control in this series of cZi DBS was achieved with stimulation of the superior part of the PSA, which corresponds to the final part of the cerebellothalamic projections before they reach the ventral lateral thalamus.

show abstract

Section: Methodsmentioning

confidence: 99%

Deep Brain Stimulation of the Caudal Zona Incerta: Tremor Control in Relation to the Location of Stimulation Fields

Fytagoridis

Åström

Samuelsson

et al. 2016

Stereotact Funct Neurosurg

View full text Add to dashboard Cite

show abstract

“…Registration was carried out with a rigid registration algorithm based on normalized gradient fields (Rü haak et al, 2015), together with a local bounding box of 30 Â 30 Â 30 mm 3 applied around the target area to define the volume used for registration. VTAs were simulated and displayed for each lead based on the applied stimulation parameters (Table 1) (Astrom et al, 2014). A mean VTA was created for each cohort by aggregating all VTAs of a single group, and allegorize only voxels that overlapped by 52 VTAs.…”

Section: Volume Of Tissue Activated Modellingmentioning

confidence: 99%

Progressive gait ataxia following deep brain stimulation for essential tremor: adverse effect or lack of efficacy?

Reich¹,

Brumberg²,

Pozzi³

et al. 2016

Brain

134

132

View full text Add to dashboard Cite

*These authors contributed equally to this work.Thalamic deep brain stimulation is a mainstay treatment for severe and drug-refractory essential tremor, but postoperative management may be complicated in some patients by a progressive cerebellar syndrome including gait ataxia, dysmetria, worsening of intention tremor and dysarthria. Typically, this syndrome manifests several months after an initially effective therapy and necessitates frequent adjustments in stimulation parameters. There is an ongoing debate as to whether progressive ataxia reflects a delayed therapeutic failure due to disease progression or an adverse effect related to repeated increases of stimulation intensity. In this study we used a multimodal approach comparing clinical stimulation responses, modelling of volume of tissue activated and metabolic brain maps in essential tremor patients with and without progressive ataxia to disentangle a disease-related from a stimulation-induced aetiology. Ten subjects with stable and effective bilateral thalamic stimulation were stratified according to the presence (five subjects) of severe chronic-progressive gait ataxia. We quantified stimulated brain areas and identified the stimulation-induced brain metabolic changes by multiple 18 F-fluorodeoxyglucose positron emission tomography performed with and without active neurostimulation. Three days after deactivating thalamic stimulation and following an initial rebound of symptom severity, gait ataxia had dramatically improved in all affected patients, while tremor had worsened to the presurgical severity, thus indicating a stimulation rather than disease-related phenomenon. Models of the volume of tissue activated revealed a more ventrocaudal stimulation in the (sub)thalamic area of patients with progressive gait ataxia. Metabolic maps of both patient groups differed by an increased glucose uptake in the cerebellar nodule of patients with gait ataxia. Our data suggest that chronic progressive gait ataxia in essential tremor is a reversible cerebellar syndrome caused by a maladaptive response to neurostimulation of the (sub)thalamic area. The metabolic signature of progressive gait ataxia is an activation of the cerebellar nodule, which may be caused by inadvertent current spread and antidromic stimulation of a cerebellar outflow pathway originating in the vermis. An anatomical candidate could be the ascending limb of the uncinate tract in the subthalamic area. Adjustments in programming and precise placement of the electrode may prevent this adverse effect and help fine-tuning deep brain stimulation to ameliorate tremor without negative cerebellar signs.

show abstract

“…However, despite an overall improvement in OCB outcome, statistical significance was not reached. Further subgroup analysis revealed that 4 patients with the most severe baseline OCB (score 24-31) showed a 38.7% (7.4-60) improvement in Y-BOCS, 5 with a moderate score [15,16,17,18,19,20,21,22] of 12.3% (-20 to 50), whilst 6 patients with mild or subclinical OCB showed little or no improvement, suggesting that the impact of DBS may be seen most in those with severe baseline OCB associated with TS. The inspection of individual patient data also revealed variability in tic outcome, with 4 patients showing a less than 20% YGTSS improvement, 6 experiencing a 20-50% improvement, and 5 displaying an over 50% improvement (Table 2).…”

Section: Resultsmentioning

confidence: 99%

“…However, previous simulation studies have shown this to be only a minor influence, compared with cerebrospinal fluid-filled cysts due to Virchow Robin spaces [27], for instance. Another parameter that is unknown is the exact distribution of axon diameters in the regions of interest; as wider diameter axons are easier to trigger, this will affect what EF isolevel is relevant for calculation of the stimulation [20]. The axon model used to calculate the triggering isolevels also contains parameters other than axon diameter that could affect the ease of activation, such as internodal length.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Refining the Deep Brain Stimulation Target within the Limbic Globus Pallidus Internus for Tourette Syndrome

Akbarian-Tefaghi

Akram

Johansson

et al. 2017

Stereotact Funct Neurosurg

View full text Add to dashboard Cite

Background: Deep brain stimulation (DBS) in patients with severe, refractory Tourette syndrome (TS) has demonstrated promising but variable results thus far. The thalamus and anteromedial globus pallidus internus (amGPi) have been the most commonly stimulated sites within the cortico-striato thalamic circuit, but an optimal target is yet to be elucidated. Objectives: This study of 15 patients with long-term amGPi DBS for severe TS investigated whether a specific anatomical site within the amGPi correlated with optimal clinical outcome for the measures of tics, obsessive compulsive behaviour (OCB), and mood. Methods: Validated clinical assessments were used to measure tics, OCB, quality of life, anxiety, and depression before DBS and at the latest follow-up (17-82 months). Electric field simulations were created for each patient using information on electrode location and individual stimulation parameters. A subsequent regression analysis correlated these patient-specific simulations to percentage changes in outcome measures in order to identify any significant voxels related to clinical improvement. Results: A region within the ventral limbic GPi, specifically on the medial medullary lamina in the pallidum at the level of the AC-PC, was significantly associated with improved tics but not mood or OCB outcome. Conclusions: This study adds further support to the application of DBS in a tic-related network, though factors such as patient sample size and clinical heterogeneity remain as limitations and replication is required.

show abstract

Relationship between Neural Activation and Electric Field Distribution during Deep Brain Stimulation

Cited by 197 publications

References 47 publications

Deep Brain Stimulation of the Caudal Zona Incerta: Tremor Control in Relation to the Location of Stimulation Fields

Deep Brain Stimulation of the Caudal Zona Incerta: Tremor Control in Relation to the Location of Stimulation Fields

Progressive gait ataxia following deep brain stimulation for essential tremor: adverse effect or lack of efficacy?

Refining the Deep Brain Stimulation Target within the Limbic Globus Pallidus Internus for Tourette Syndrome

Contact Info

Product

Resources

About