Deep Brain Stimulation Research Articles

Translational evaluation of metabolic risk factors impacting DBS efficacy for PD-Related sleep and depressive disorders: preclinical, prospective and cohort studies.

Parkinson's disease (PD) is linked with metabolic risk factors including body mass index (BMI), fasting blood glucose (FBG), cholesterol levels, and triglycerides (TG). The extent to which these factors affect motor symptoms, depression, and sleep problems in PD, as well as their role in determining the success of deep brain stimulation (DBS) therapy, is yet to be fully understood. This study delved into the effects of metabolic risk factors like BMI, FBG, cholesterol, and TG on the outcomes of DBS in treating PD-related depression and sleep disturbances, across both mouse models and human subjects. DBS showcased noticeable betterment in depression and sleep perturbations in both PD-afflicted mice and patients. High-sugar-high-fat diet aggravates MPTP-induced depression and sleep disorders in mice. PD-afflicted individuals presenting with depressive and sleep disorders demonstrated elevated metrics of BMI, FBG, blood cholesterol, and TG. Remarkably, these metrics bore considerable adverse influences on the efficiency of DBS in ameliorating depression and sleep issues, yet spared motor symptoms. The favorable impacts of DBS persisted for approximately 6 years, post which a significant decline was noted. Importantly, our translational evidence from both murine controls and patient cohorts indicated that antihyperglycemic and antihyperlipidemic therapies bolstered the efficacy of DBS in mitigating PD-related depression and sleep disturbances, without impinging upon motor functions in patients. In summary, this research emphasizes that DBS is a powerful treatment option for depression and sleep issues in PD, with its success influenced by metabolic risk factors. It further suggests that incorporating treatments for high blood sugar and cholesterol can enhance the efficacy of DBS in treating depression and sleep disturbances in PD, without impacting motor symptoms, highlighting the importance of metabolic risk management in PD patients receiving DBS.

Utilizing diffusion tensor imaging as an image biomarker in exploring the therapeutic efficacy of forniceal deep brain stimulation in a mice model of Alzheimer’s disease

Objective.With prolonged life expectancy, the incidence of memory deficits, especially in Alzheimer's disease (AD), has increased. Although multiple treatments have been evaluated, no promising treatment has been found to date. Deep brain stimulation (DBS) of the fornix area was explored as a possible treatment because the fornix is intimately connected to memory-related areas that are vulnerable in AD; however, a proper imaging biomarker for assessing the therapeutic efficiency of forniceal DBS in AD has not been established.Approach.This study assessed the efficacy and safety of DBS by estimating the optimal intersection volume between the volume of tissue activated and the fornix. Utilizing a gold-electroplating process, the microelectrode's surface area on the neural probe was increased, enhancing charge transfer performance within potential water window limits. Bilateral fornix implantation was conducted in triple-transgenic AD mice (3 × Tg-AD) and wild-type mice (strain: B6129SF1/J), with forniceal DBS administered exclusively to 3 × Tg-AD mice in the DBS-on group. Behavioral tasks, diffusion tensor imaging (DTI), and immunohistochemistry (IHC) were performed in all mice to assess the therapeutic efficacy of forniceal DBS.Main results.The results illustrated that memory deficits and increased anxiety-like behavior in 3 × Tg-AD mice were rescued by forniceal DBS. Furthermore, forniceal DBS positively altered DTI indices, such as increasing fractional anisotropy (FA) and decreasing mean diffusivity (MD), together with reducing microglial cell and astrocyte counts, suggesting a potential causal relationship between revised FA/MD and reduced cell counts in the anterior cingulate cortex, hippocampus, fornix, amygdala, and entorhinal cortex of 3 × Tg-AD mice following forniceal DBS.Significance.The efficacy of forniceal DBS in AD can be indicated by alterations in DTI-based biomarkers reflecting the decreased activation of glial cells, suggesting reduced neural inflammation as evidenced by improvements in memory and anxiety-like behavior.

Risk Factors for Postoperative Delirium Severity After Deep Brain Stimulation Surgery in Parkinson's Disease.

Postoperative delirium (POD) is a serious complication following deep brain stimulation (DBS) but only received little attention. Its main risk factors are higher age and preoperative cognitive deficits. These are also main risk factors for long-term cognitive decline after DBS in Parkinson's disease (PD). To identify risk factors for POD severity after DBS surgery in PD. 57 patients underwent DBS (21 female; age 60.2±8.2; disease duration 10.5±5.9 years). Preoperatively, general, PD- and surgery-specific predictors were recorded. Montreal Cognitive Assessment and the neuropsychological test battery CANTAB ConnectTM were used to test domain-specific cognition. Volumes of the cholinergic basal forebrain were calculated with voxel-based morphometry. POD severity was recorded with the delirium scales Confusion Assessment Method for Intensive Care Unit (CAM-ICU) and Nursing Delirium Scale (NU-DESC). Spearman correlations were calculated for univariate analysis of predictors and POD severity and linear regression with elastic net regularization and leave-one-out cross-validation was performed to fit a multivariable model. 21 patients (36.8%) showed mainly mild courses of POD following DBS. Correlation between predicted and true POD severity was significant (spearman rho = 0.365, p = 0.001). Influential predictors were age (p < 0.001), deficits in attention and motor speed (p = 0.002), visual learning (p = 0.036) as well as working memory (p < 0.001), Nucleus basalis of Meynert volumes (p = 0.003) and burst suppression (p = 0.005). General but also PD- and surgery-specific factors were predictive of POD severity. These findings underline the multifaceted etiology of POD after DBS in PD. Valid predictive models must therefore consider general, PD- and surgery-specific factors.

Deep brain stimulation for post-stroke rehabilitation in Pakistan

Stroke has a high prevalence in Pakistan, at an alarming rate of 250 per 100,000 people. Although various treatment options are available, they are not ideal for Pakistan due to their high cost, restricted availability, and time sensitivity. In 1997, the FDA approved Deep Brain Stimulation (DBS) for Parkinson’s disease and it was first performed in Pakistan in 2014. DBS has also proved effective for restoring post-stroke mobility, according to a trial from August, 2023. DBS has the potential to revolutionise post-stroke rehabilitation in Pakistan; however, further research is required into its effectiveness and its limitations must be addressed first.

Unmet Need in Early-Onset Parkinson's Disease: Deep Brain Stimulation and Pregnancy.

Pregnancy in women with early-onset Parkinson's disease (PD) is likely to have a higher frequency given the trend toward increasing maternal age, thus resulting in a greater overlap time between childbearing age and PD risk. Deep brain stimulation (DBS) therapy is nowadays offered to PD patients at earlier stage of the disease, when women can still be pre-menopausal. However, few data are available about DBS safety during pregnancy. From a review of the available literature, only one article was published on this topic so far. Therefore, we have developed a clinical consensus on the safety of DBS during pregnancy in PD patients.

Quality of Life after Deep Brain Stimulation in Parkinson's Disease: Does the Target Matter?

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus internus (GPi) is an accepted therapy for Parkinson's disease (PD) with disabling motor complications. For elderly patients with poorer cognition and postural instability, GPi has been proposed as the preferable DBS target based on expert opinion, arguing GPi-DBS may be less complicated by depression, apathy, worsened verbal fluency, and executive dysfunction, resulting in greater improvement in quality of life (QoL). However, data supporting such patient-tailored approach are lacking. The aims were to analyze whether the DBS target influences QoL in a PD cohort and a matched subgroup of frail patients with poor cognitive status and reduced postural stability, and whether other factors affect the QoL outcomes. In this retrospective study, we analyzed a single-center cohort of 138 PD patients who received bilateral STN-DBS (117) or GPi-DBS (21) using the mentioned approach for target selection. All patients underwent standardized clinical evaluations of motor- and nonmotor signs as well as QoL before and 1 year after surgery. DBS of both targets improved motor signs, dyskinesias, and pain. QoL improved without significant difference between the targets, but with a trend for greater improvement across all QoL domains in favor of the STN, even in an STN subgroup matched to the GPi group. Our results contradict the prevailing belief that GPi-DBS is superior in frail PD patients with cognitive decline and postural instability, questioning the proposed patient-tailored approach of DBS target selection. Further studies are needed for a data-driven approach.

Deep brain stimulation for obsessive compulsive disorder: the functional neurosurgeon armamentarium.

Deep brain stimulation (DBS) is a neurosurgical procedure that utilizes implanted electrodes and electrical stimulation for the treatment of neurological disorders. In cases where patients present with severe functional impairment while being refractory to less invasive treatment options, DBS is considered "gold standard." Still, DBS-related work is still widely under investigation, with ethical issues arising that may impact a patient's physical and psycho-social status. These include patient selection, informed consent, patient autonomy, pre-operation counseling and professional psycho-social preparation and follow-up support. Bioethicists and philosophers have increasingly worked together with in clinicians and researchers to identify, address and present ethical consideration in both clinical practice and research to balance the risk-benefit ratio in DBS treatment for obsessive-compulsive disorder.

Efficacy of subthalamic deep brain stimulation programming strategies for gait disorders in Parkinson's disease: a systematic review and meta-analysis.

Patients with advanced Parkinson's disease often suffer from severe gait and balance problems, impacting quality of live and persisting despite optimization of standard therapies. The aim of this review was to systematically review the efficacy of STN-DBS programming techniques in alleviating gait disturbances in patients with advanced PD. Searches were conducted in PubMed, Embase, and Lilacs databases, covering studies published until May 2024. The review identified 36 articles that explored five distinct STN-DBS techniques aimed at addressing gait and postural instability in Parkinson's patients: low-frequency stimulation, ventral STN stimulation for simultaneous substantia nigra activation, interleaving, asymmetric stimulation and a short pulse width study. Among these, 21 articles were included in the meta-analysis, which revealed significant heterogeneity among studies. Notably, low-frequency STN-DBS demonstrated positive outcomes in total UPDRS-III score and FOG-Q, especially when combined with dopaminergic therapy. The most favorable results were found for low-frequency STN stimulation. The descriptive analysis suggests that unconventional stimulation approaches may be viable for gait problems in patients who do not respond to standard therapies.

Brain state identification and neuromodulation to promote recovery of consciousness.

Experimental and clinical studies of consciousness identify brain states (i.e. quasi-stable functional cerebral organization) in a non-systematic manner and largely independent of the research into brain state modulation. In this narrative review, we synthesize advances in the identification of brain states associated with consciousness in animal models and physiological (sleep), pharmacological (anaesthesia) and pathological (disorders of consciousness) states of altered consciousness in humans. We show that in reduced consciousness the frequencies in which the brain operates are slowed down and that the pattern of functional communication is sparser, less efficient, and less complex. The results also highlight damaged resting-state networks, in particular the default mode network, decreased connectivity in long-range connections and especially in the thalamocortical loops. Next, we show that therapeutic approaches to treat disorders of consciousness, through pharmacology (e.g. amantadine, zolpidem), and (non-) invasive brain stimulation (e.g. transcranial direct current stimulation, deep brain stimulation) have shown partial effectiveness in promoting consciousness recovery. Although some features of conscious brain states may improve in response to neuromodulation, targeting often remains non-specific and does not always lead to (behavioural) improvements. The fields of brain state identification and neuromodulation of brain states in relation to consciousness are showing fascinating developments that, when integrated, might propel the development of new and better-targeted techniques for disorders of consciousness. We here propose a therapeutic framework for the identification and modulation of brain states to facilitate the interaction between the two fields. We propose that brain states should be identified in a predictive setting, followed by theoretical and empirical testing (i.e. in animal models, under anaesthesia and in patients with a disorder of consciousness) of neuromodulation techniques to promote consciousness in line with such predictions. This framework further helps to identify where challenges and opportunities lay for the maturation of brain state research in the context of states of consciousness. It will become apparent that one angle of opportunity is provided through the addition of computational modelling. Finally, it aids in recognizing possibilities and obstacles for the clinical translation of these diagnostic techniques and neuromodulation treatment options across both the multimodal and multi-species approaches outlined throughout the review.

The cingulum: a central hotspot for the battle against chronic intractable pain?

Chronic pain causes a major burden on patient's lives, in part due to its profound socioeconomic impact. Despite the development of various pharmacological approaches and (minor) invasive treatments, a subset of patients remain refractory, hence why alternative targeted neurosurgical interventions like cingulotomy and deep brain stimulation of the anterior cingulate cortex should be considered in the last resort. Despite clinical evidence supporting the potential of these treatments in the management of chronic intractable pain, physicians remain reluctant on its clinical implementation. This can be partially attributed to the lack of clear overviews summarizing existent data. Hence, this article aims to evaluate the current status of cingulotomy and deep brain stimulation of the anterior cingulate cortex in the treatment of chronic intractable pain, to provide insight in whether these neurosurgical approaches and its target should be reconsidered in the current era. In the current study, a literature searches was performed using the PubMed database. Additional articles were searched manually through reviews or references cited within the articles. After exclusion, 24 and 5 articles remained included in the analysis of cingulotomy and deep brain stimulation of the anterior cingulate cortex, respectively. Results indicate that various surgical techniques have been described for cingulotomy and deep brain stimulation of the anterior cingulate cortex. Cingulotomy is shown to be effective 51-53% and 43-64% of patients with neoplastic and non-neoplastic pain at ≤6 months follow-up, and 82% (9/11) and 76% (90/118) at ≥ 12months follow-up, respectively. With regard to deep brain stimulation of the anterior cingulate cortex, no data on neoplastic pain was reported, however, 59% (10/17) and 57% (8/14) of patients with non-neoplastic pain were considered responders at ≤ 6 months and ≥ 12months follow-up, respectively. The most reported adverse events include change in affect (>6.9%, >29/420) and confusion (>4.8%, >20/420) for cingulotomy, and infection (12.8%, 6/47), seizures (8.5%, 4/47) and decline in semantic fluency (6.4%, 3/47) for deep brain stimulation of the anterior cingulate cortex. It can be concluded that cingulotomy and deep brain stimulation of the anterior cingulate cortex are effective last resort strategies for patients with refractory non-neoplastic and neoplastic pain, especially in case of an affective emotional component. Future research should be performed on the cingulum as a neurosurgical target as it allows for further exploration of promising treatment options for chronic intractable pain.

Deep brain stimulation targets in drug-resistant epilepsy: Systematic review and meta-analysis of effectiveness and predictors of response

PurposeAnterior nucleus of the thalamus (ANT) is the only deep brain stimulation (DBS) target that is approved by the FDA for treatment of drug-resistant epilepsy (DRE). Hippocampus (HC) and centromedian nucleus (CMN) have been reported as potential DBS targets for DRE. This study aimed to assess the effectiveness and predictors of response among DRE patients treated with DBS in general and among ANT, HC and CMN DBS-targets. MethodsA systematic search was executed on PubMed, SCOPUS and the Cochrane Central Register of Controlled Trials (CENTRAL) electronic databases between Jan 1, 2000 and June 29, 2020. Patients with DRE who underwent DBS treatment with at least three months of follow-up were included. Individual patient data (IPD) meta-analysis was conducted on DBS studies with available IPD. Response was defined as ≥50 % reduction in seizures frequency. Responders group was compared with non-responders group in terms of demographics, epilepsy/seizure characteristics, MRI findings, and DBS targets and duration of use. Subsequently, predictors of response to different DBS targets were investigated. ResultsThirty-nine studies with a total of 296 patients (ANT: 69 %, HC: 11 %, CMN: 21 %) were included. The responders group constituted of 209 patients (70.6 %). The response was significantly higher in patients with generalized seizures compared to those with focal seizures (93.2% vs 63.9 %; p < 0.001). Response was significantly higher with CMN (83.9 %) and HC (77.4 %) compared with ANT (65.5 %) as DBS targets (p = 0.014). Response was also significantly associated with longer duration of DBS use (p = 0.008). The responder rate was higher among the patients with lesional MRIs (76.7 %) than those with non-lesional MRIs (66.7 %), but with no statistically significant difference (p = 0.134). Age, gender, epilepsy etiology, onset zone of focal seizures, and previous use of VNS had no significant differences between the responders and non-responders. A binary logistic regression including the seizure type, MRI findings, DBS targets, and DBS duration showed, after controlling for confounders, that the duration of DBS use was the only significant predictor of response (adjusted OR 1.061; 95 % CI 1.019–1.106; p = 0.005). Regarding DBS targets, the response rate in patients with symptomatic etiology was significantly higher with HC or CMN targets than the ANT (p = 0.003). In patients with non-lesional MRI, response rate was significantly higher with the CMN target compared to the other two targets (p = 0.008). ConclusionDBS proves to be effective in DRE, with progressive success upon longer treatment and possibility of improving quality of life. In addition to focal seizures, DBS has potential for treating generalized seizures as well. While the ANT stands as the most utilized and only approved DBS target for DRE, CMN and HC are alternative targets with high seizure control potential. Patients with symptomatic etiology showed significant seizure reduction when HC or CMN were targeted. Studies revealed noticeable effectiveness of CMN-DBS in treating patients with non-lesional MRI. Despite ANT prominence in research, our findings suggest promising outcomes with CMN and HC, emphasizing the need for future larger-scale comparative clinical trials to better understand the efficacy of different DBS targets.

Focused Ultrasound as Rescue Treatment of Essential Tremor After Deep Brain Stimulation: 2 Case Reports

BACKGROUND AND IMPORTANCE: Approximately 25% to 55% of patients with essential tremor will eventually develop medication-refractory tremor. Currently, the standard surgical treatment for this condition is deep brain stimulation (DBS) of the ventralis intermedius nucleus of the thalamus and, more recently, the posterior subthalamic area. However, MRI-guided focused ultrasound (FUS) thalamotomy has shown promising results in improving tremor in patients with refractory essential tremor. CLINICAL PRESENTATION: We present 2 cases of patients with a disabling action tremor, recurring after DBS. A 55-year-old right-handed male and a 52-year-old woman presented with bilateral medically refractory action tremor, which began in their second decade of life. Both underwent bilateral DBS-ventralis intermedius, with the first patient showing a good initial response but the second patient showing a suboptimal response within the first year after DBS. In both cases, the DBS system was removed and the patients subsequently underwent left-sided FUS thalamotomy with a dramatic improvement of their tremor. CONCLUSION: These cases demonstrate the feasibility of performing FUS thalamotomy as a rescue treatment for disabling tremor after DBS.

Cervical dystonia patients with psychiatric classification: Despite dystonia improvement less improvement in other domains after DBS surgery

BackgroundPatient satisfaction of deep brain stimulation (DBS) for cervical dystonia (CD) is heterogeneous. A high prevalence of psychiatric disorders in patients with CD is well-established. The presence of psychiatric classification in CD may affect the outcomes of DBS treatment. MethodsA cohort of 49 patients with CD and GPi-DBS was retrospectively studied in two centers. Psychiatric history was obtained from patient records. Pre- and post-operative Toronto Western Spasmodic Torticollis Rating Scores (TWSTRS, range 0–85) were compared between patients with and those without psychiatric classification. The TWSTRS disability and pain sub-scores were combined to evaluate non-motor improvement. The severity sub-score was used to assess motor improvement. ResultsTwenty (40.8 %) patients had a psychiatric classification, predominantly major depressive disorder and anxiety disorders. Following DBS treatment, the overall mean (± SD) improvement on the TWSTRS was 38.0 ± 29.2 %. Significantly, patients with a psychiatric classification experienced less improvement in the non-motor domain than the patients without a psychiatric classification (29.1 ± SD 38.2 % [range −41.7 to 96.6 %] vs. 51.9 ± 33.6 % [range −8.6 to 100.0 %]; p = 0.02). ConclusionOur findings indicate that CD patients with psychiatric classifications experience less non-motor improvement following DBS. Psychiatric comorbidities could influence the lacking experience of successful DBS treatment despite good motor outcome. Therefore, it is important to establish these comorbidities in CD patients undergoing DBS with respect to expectation management and treatment if necessary.

Cost-Utility Analysis of Deep Brain Stimulation for Generalized and Cervical Dystonia: A Perspective from Brazilian Healthcare

ObjectiveIn the Brazilian public national healthcare system, botulinum toxin type A has traditionally been the sole treatment option for patients with dystonia. However, as of October 2022, Deep Brain Stimulation (DBS) garnered positive recommendations for the condition. This study aims to assess the cost-effectiveness of DBS in treating adults with generalized and cervical dystonia within the Brazilian healthcare context, considering its recent inclusion. MethodsA systematic review identified randomized controlled trials (RCTs) assessing DBS efficacy in treating adults with generalized and cervical dystonia. Two cost-utility analyses compared the cost-effectiveness of DBS plus the Best Clinical Practice (BCP) to BCP alone. Markov models, which included three health states (no clinical improvement, clinical improvement, and death), employed a one-year cycle and a lifetime horizon. The study utilized both one-way and probabilistic sensitivity analyses. ResultsTwo RCTs, one for each condition, revealed superior clinical improvement with DBS when compared to sham simulation. The Incremental Cost-Utility Ratio (ICUR) was $ 1,121.66 for generalized dystonia and $4,556.50 for cervical dystonia. Effectiveness discount rates and age at surgery were identified as influential parameters. In 1,000 Monte Carlo simulations, 99.9% of the ICUR values for generalized dystonia and 74.2 % for cervical dystonia fell below the cost-effectiveness threshold in Brazil ($8,146.64 per QALY). ConclusionsFrom the perspective of the Brazilian public health system, the combination of DBS and BCP appears to be cost-effective for the treatment of both generalized and cervical dystonia when compared to BCP alone.

State-specific Regulation of Electrical Stimulation in the Intralaminar Thalamus of Macaque Monkeys: Network and Transcriptional Insights into Arousal.

Long-range thalamocortical communication is central to anesthesia-induced loss of consciousness and its reversal. However, isolating the specific neural networks connecting thalamic nuclei with various cortical regions for state-specific anesthesia regulation is challenging, with the biological underpinnings still largely unknown. Here, simultaneous electroencephalogram-fuctional magnetic resonance imaging(EEG-fMRI) and deep brain stimulation are applied to the intralaminar thalamus in macaques under finely-tuned propofol anesthesia. This approach led to the identification of an intralaminar-driven network responsible for rapid arousal during slow-wave oscillations. A network-based RNA-sequencing analysis is conducted of region-, layer-, and cell-specific gene expression data from independent transcriptomic atlases and identifies 2489 genes preferentially expressed within this arousal network, notably enriched in potassium channels and excitatory, parvalbumin-expressing neurons, and oligodendrocytes. Comparison with human RNA-sequencing data highlights conserved molecular and cellular architectures that enable the matching of homologous genes, protein interactions, and cell types across primates, providing novel insight into network-focused transcriptional signatures of arousal.

Brain targeting for focused ultrasound essential tremor ablation: proceedings from the 2023 Focused Ultrasound Foundation workshop.

Essential tremor (ET) is the most common movement disorder globally and has negative impacts on quality of life. While medical treatments exist, approximately 50% of patients have tremor that is refractory to medication or experience intolerable medication side effects. Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is an option for these patients and while incisionless, it is still invasive, although less so than other surgical treatments such as deep brain stimulation and radiofrequency thalamotomy. Despite MRgFUS being FDA-approved since 2016, there is still no current consensus on the best approaches for targeting, imaging, and outcome measurement. A 2-day workshop held by the Focused Ultrasound Foundation in September of 2023 convened experts and critical stakeholders in the field to share their knowledge and experiences. The goals of the workshop were to determine the optimal target location within the thalamus and compare best practices for localizing the target and tracking patient outcomes. This paper summarizes the current landscape, important questions, and discussions that will help direct future treatments to improve patient care and outcomes.

Electrographic seizures during low-current thalamic deep brain stimulation in mice.

Deep brain stimulation of the central thalamus (CT-DBS) has potential for modulating states of consciousness, but it can also trigger electrographic seizures, including poly-spike-wave trains (PSWT). To report the probability of inducing PSWTs during CT-DBS in awake, freely-moving mice. Mice were implanted with electrodes to deliver unilateral and bilateral CT-DBS at different frequencies while recording electroencephalogram (EEG). We titrated stimulation current by gradually increasing it at each frequency until a PSWT appeared. Subsequent stimulations to test arousal modulation were performed at the current one step below the current that caused a PSWT during titration. In 2.21% of the test stimulations (10 out of 12 mice), CT-DBS caused PSWTs at currents lower than the titrated current, including currents as low as 20 μA. Our study found a small but significant probability of inducing PSWTs even after titration and at relatively low currents. EEG should be closely monitored for electrographic seizures when performing CT-DBS in both research and clinical settings.

Directional Deep Brain Stimulation Lead Rotation in the Early Postoperative Period

BACKGROUND AND OBJECTIVES: Directional deep brain stimulation (DBS) enables treatment optimization by current steering using segmented leads. Identification of the lead's rotational orientation is critical to guide programming decisions. Orientation is often assessed during or immediately after implant, but the degree of lead rotation in the following weeks is not well appreciated. Our objective was to measure the degree of DBS lead rotational orientation changes within the first few weeks after surgery. METHODS: We retrospectively reviewed the clinical records of patients who were implanted with segmented DBS leads at our institution. All included patients had at least 1 immediate postoperative computed tomography (CT) (CT1) and another CT at least 1 week later (CT2). We assessed lead rotational orientation angles on CT1 and CT2 and calculated the degrees of rotation change between the scans. We also assessed for any effect of the time interval between scans by calculating the correlation between CT1-CT2 latency and degrees of lead rotation. RESULTS: We assessed a total of 75 DBS lead orientations for 38 patients. The average change in lead orientation between CT1 and CT2 was 8.6° (median = 2.9°, range = 0.11-168.2°). Only 8 percent of patients (3/38) were found to have a significant change in orientation (&gt;30°); however, when it occurred, it occurred bilaterally. There was no correlation between CT1-CT2 latency and lead rotation (r(74) = 0.04, P = .73). CONCLUSION: Our study finds that changes in lead orientation occurring over the first few weeks after surgery are rare. Thus, for most patients, the immediate postoperative CT is adequate for determining the orientation angles for clinical programming. However, if programming is found to be difficult, a repeat CT scan could be beneficial for a minority of patients.

Responsive Deep Brain Stimulation: A New Hope for Controlling Stimulation‐Induced Dysarthria in Essential Tremor

Responsive Deep Brain Stimulation: A New Hope for Controlling Stimulation‐Induced Dysarthria in Essential Tremor

Carry-Over Effect of Deep Cerebellar Stimulation-Mediated Motor Recovery in a Rodent Model of Traumatic Brain Injury

Background We previously demonstrated that deep brain stimulation (DBS) of lateral cerebellar nucleus (LCN) can enhance motor recovery and functional reorganization of perilesional cortex in rodent models of stroke or TBI. Objective Considering the treatment-related neuroplasticity observed at the perilesional cortex, we hypothesize that chronic LCN DBS-enhanced motor recovery observed will carry-over even after DBS has been deactivated. Methods Here, we directly tested the enduring effects of LCN DBS in male Long Evans rats that underwent controlled cortical impact (CCI) injury targeting sensorimotor cortex opposite their dominant forepaw followed by unilateral implantation of a macroelectrode into the LCN opposite the lesion. Animals were randomized to DBS or sham treatment for 4 weeks during which the motor performance were characterize by behavioral metrics. After 4 weeks, stimulation was turned off, with assessments continuing for an additional 2 weeks. Afterward, all animals were euthanized, and tissue was harvested for further analyses. Results Treated animals showed significantly greater motor improvement across all behavioral metrics relative to untreated animals during the 4-week treatment, with functional gains persisting across 2-week post-treatment. This motor recovery was associated with the increase in CaMKIIα and BDNF positive cell density across perilesional cortex in treated animals. Conclusions LCN DBS enhanced post-TBI motor recovery, the effect of which was persisted up to 2 weeks beyond stimulation offset. Such evidence should be considered in relation to future translational efforts as, unlike typical DBS applications, treatment may only need to be provided until such time as a new function plateau is achieved.