Bilateral Deep Brain Stimulation Research Articles

Speech, voice, and language outcomes following deep brain stimulation: A systematic review.

Deep brain stimulation (DBS) reliably ameliorates cardinal motor symptoms in Parkinson's disease (PD) and essential tremor (ET). However, the effects of DBS on speech, voice and language have been inconsistent and have not been examined comprehensively in a single study. We conducted a systematic analysis of literature by reviewing studies that examined the effects of DBS on speech, voice and language in PD and ET. A total of 675 publications were retrieved from PubMed, Embase, CINHAL, Web of Science, Cochrane Library and Scopus databases. Based on our selection criteria, 90 papers were included in our analysis. The selected publications were categorized into four subcategories: Fluency, Word production, Articulation and phonology and Voice quality. The results suggested a long-term decline in verbal fluency, with more studies reporting deficits in phonemic fluency than semantic fluency following DBS. Additionally, high frequency stimulation, left-sided and bilateral DBS were associated with worse verbal fluency outcomes. Naming improved in the short-term following DBS-ON compared to DBS-OFF, with no long-term differences between the two conditions. Bilateral and low-frequency DBS demonstrated a relative improvement for phonation and articulation. Nonetheless, long-term DBS exacerbated phonation and articulation deficits. The effect of DBS on voice was highly variable, with both improvements and deterioration in different measures of voice. This was the first study that aimed to combine the outcome of speech, voice, and language following DBS in a single systematic review. The findings revealed a heterogeneous pattern of results for speech, voice, and language across DBS studies, and provided directions for future studies.

Disentangling Bradykinesia and Rigidity in Parkinson Disease: Evidence from Short- and Long-Term Subthalamic Nucleus Deep Brain Stimulation.

Bradykinesia and rigidity are considered closely related motor signs in Parkinson disease (PD), but recent neurophysiological findings suggest distinct pathophysiological mechanisms. This study aims to examine and compare longitudinal changes in bradykinesia and rigidity in PD patients treated with bilateral subthalamic nucleus deep brain stimulation (STN-DBS). In this retrospective cohort study, the clinical progression of appendicular and axial bradykinesia and rigidity was assessed up to 15 years after STN-DBS in the best treatment conditions (ON medication and ON stimulation). The severity of bradykinesia and rigidity was examined using ad hoc composite scores from specific subitems of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III). Short- and long-term predictors of bradykinesia and rigidity were analyzed through linear regression analysis, considering various preoperative demographic and clinical data, including disease duration and severity, phenotype, motor and cognitive scores (eg, frontal score), and medication. A total of 301 patients were examined before and 1 year after surgery. Among them, 101 and 56 individuals were also evaluated at 10-year and 15-year follow-ups, respectively. Bradykinesia significantly worsened after surgery, especially in appendicular segments (p < 0.001). Conversely, rigidity showed sustained benefit, with unchanged clinical scores compared to preoperative assessment (p > 0.05). Preoperative motor disability (eg, composite scores from the UPDRS-III) predicted short- and long-term outcomes for both bradykinesia and rigidity (p < 0.01). Executive dysfunction was specifically linked to bradykinesia but not to rigidity (p < 0.05). Bradykinesia and rigidity show long-term divergent progression in PD following STN-DBS and are associated with independent clinical factors, supporting the hypothesis of partially distinct pathophysiology. ANN NEUROL 2024.

Deep brain stimulation of the amygdala for treatment-resistant combat post-traumatic stress disorder: Long-term results

Deep brain stimulation (DBS) holds promise for neuropsychiatric conditions where imbalance in network activity contributes to symptoms. Treatment-resistant Combat post-traumatic stress disorder (TR-PTSD) is a highly morbid condition and 50% of PTSD sufferers fail to recover despite psychotherapy or pharmacotherapy. Reminder-triggered symptoms may arise from inadequate top-down ventromedial prefrontal cortex (vmPFC) control of amygdala reactivity. Here, we report long-term data on two TR-PTSD participants from an investigation utilizing high-frequency amygdala DBS. The two combat veterans were implanted bilaterally with quadripolar electrodes targeting the basolateral amygdala. Following a randomized staggered onset, patients received stimulation with adjustments based on PTSD symptom severity for four years while psychiatric and neuropsychiatric symptoms, neuropsychological performance, and electroencephalography were systematically monitored. Evaluation of vmPFC-Amygdala network engagement was assessed with 18FDG positron emission tomography (PET). CAPS-IV scores varied over time, but improved 55% from 119 at baseline to 53 at 4-year study endpoint in participant 1; and 44%, from 68 to 38 in participant 2. Thereafter, during 5 and 1.5 years of subsequent clinical care respectively, long-term bilateral amygdala DBS was associated with additional, clinically significant symptomatic and functional improvement. There were no serious stimulation-related adverse psychiatric, neuropsychiatric, neuropsychological, neurological, or neurosurgical effects. In one subject, symptomatic improvement was associated with an intensity-dependent reduction in amygdala theta frequency power. In our two participants, FDG-PET findings were inconclusive regarding the hypothesized mechanism of suppression of amygdala hyperactivity. Our findings encourage further research to confirm and extend our preliminary observations.

Protocol for combined N-of-1 trials to assess cerebellar neurostimulation for movement disorders in children and young adults with dyskinetic cerebral palsy.

Movement and tone disorders in children and young adults with cerebral palsy are a great source of disability. Deep brain stimulation (DBS) of basal ganglia targets has a major role in the treatment of isolated dystonias, but its efficacy in dyskinetic cerebral palsy (DCP) is lower, due to structural basal ganglia and thalamic damage and lack of improvement of comorbid choreoathetosis and spasticity. The cerebellum is an attractive target for DBS in DCP since it is frequently spared from hypoxic ischemic damage, it has a significant role in dystonia network models, and small studies have shown promise of dentate stimulation in improving CP-related movement and tone disorders. Ten children and young adults with DCP and disabling movement disorders with or without spasticity will undergo bilateral DBS in the dorsal dentate nucleus, with the most distal contact ending in the superior cerebellar peduncle. We will implant Medtronic Percept, a bidirectional neurostimulator that can sense and store brain activity and deliver DBS therapy. The efficacy of cerebellar DBS in improving quality of life and motor outcomes will be tested by a series of N-of-1 clinical trials. Each N-of-1 trial will consist of three blocks, each consisting of one month of effective stimulation and one month of sham stimulation in a random order with weekly motor and quality of life scales as primary and secondary outcomes. In addition, we will characterize abnormal patterns of cerebellar oscillatory activity measured by local field potentials from the intracranial electrodes related to clinical assessments and wearable monitors. Pre- and 12-month postoperative volumetric structural and functional MRI and diffusion tensor imaging will be used to identify candidate imaging markers of baseline disease severity and response to DBS. Our goal is to test a cerebellar neuromodulation therapy that produces meaningful changes in function and well-being for people with CP, obtain a mechanistic understanding of the underlying brain network disorder, and identify physiological and imaging-based predictors of outcomes useful in planning further studies. ClinicalTrials.gov NCT06122675, first registered November 7, 2023.

Bilateral Deep Brain Stimulation of the Ventral Intermediate Nucleus of the Thalamus Improves Objective Acoustic Measures of Essential Vocal Tremor

BACKGROUND AND OBJECTIVES: Deep brain stimulation of the ventral intermediate nucleus of the thalamus (VIM-DBS) is an established treatment for medically refractory essential tremor. However, the effect of VIM-DBS on vocal tremor remains poorly understood, with results varying by method of vocal tremor assessment and stimulation laterality. This single-center study measures the effect of bilateral VIM-DBS on essential vocal tremor using blinded objective acoustic voice analysis. METHODS: Ten patients with consecutive essential tremor with comorbid vocal tremor receiving bilateral VIM-DBS underwent voice testing before and after implantation of DBS in this prospective cohort study. Objective acoustic measures were extracted from the middle one second of steady-state phonation including cepstral peak prominence, signal-to-noise ratio, percentage voicing, tremor rate, extent of fundamental frequency modulation, and extent of intensity modulation. DBS surgery was performed awake with microelectrode recording and intraoperative testing. Postoperative voice testing was performed after stable programming. RESULTS: Patients included 6 female and 4 male, with a mean age of 67 ± 6.7 years. The VIM was targeted with the following coordinates relative to the mid-anterior commissure:posterior commissure point: 13.2 ± 0.6 mm lateral, 6.2 ± 0.7 mm posterior, and 0.0 mm below. Mean programming parameters were amplitude 1.72.0 ± 0.6 mA, pulse width 63.0 ± 12.7 µs, and rate 130.6 ± 0.0 Hz. VIM-DBS significantly improved tremor rate from 4.43 ± 0.8 Hz to 3.2 ± 0.8 Hz (P = .001) CI (0.546, 1.895), jitter from 1 ± 0.94 to 0.53 ± 0.219 (P = .02) CI (−0.124, 1.038), cepstral peak prominence from 13.6 ± 3.9 to 18.8 ± 2.9 (P = .016) CI (−4.100, −0.235), signal-to-noise ratio from 15.7 ± 3.9 to 18.5 ± 3.7 (P = .02) CI (−5.598, −0.037), and articulation rate from 0.77 ± 0.2 to 0.82 ± .14 (P = .04) CI (−0.097, 0.008). There were no major complications in this series. CONCLUSION: Objective acoustic voice analyses suggest that bilateral VIM-DBS effectively reduces vocal tremor rate and improves voicing. Further studies using objective acoustic analyses and laryngeal imaging may help refine surgical and stimulation techniques and evaluate the effect of laterality on vocal tremor.

Assessment of lmage-guided Programming (IGP) on Bilateral STN and GPi Deep Brain Stimulation Programming Time (P1-3.003)

Assessment of lmage-guided Programming (IGP) on Bilateral STN and GPi Deep Brain Stimulation Programming Time (P1-3.003)

490 Unilateral Subthalamic Nucleus Deep Brain Stimulation Improves Motor Symptoms Without Neurocognitive Worsening in Parkinsons Disease

INTRODUCTION: Bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a well-established surgical intervention for patients with medically refractory Parkinson’s disease (PD). Numerous reports have described adverse nonmotor side effects, such as declines in verbal fluency and working memory, following bilateral implantation. Unilateral STN DBS is a possible alternative; however, it remains unclear whether unilateral implantation meaningfully reduces harmful effects on cognition. METHODS: This retrospective cohort study utilized chart review to collect pre- and postoperative Unified Parkinson’s Disease Rating Scale (UPDRS)-III, Levodopa Equivalent Daily Dosage (LEDD), imaging, and neurocognitive test results from 32 patients (unilateral, n = 12; bilateral, n = 20). For all statistical comparisons, p-values less than or equal to 0.05 were considered statistically significant. Student’s unpaired and paired T-tests were used to assess for differences between groups and within groups, respectively. RESULTS: There was no difference across 17 preoperative neurocognitive tests. Both unilateral and bilateral STN DBS resulted in significant decreases in postoperative UPDRS-III and LEDD (unilateral: p &lt; 0.0001; bilateral: p &lt; 0.0001) scores. There were no differences in the absolute decreases in UPDRS (p=0.055) and LEDD (p=0.120) scores between the groups. The bilateral STN DBS group had a significant deterioration in verbal fluency (COWAT FAS, p = 0.002; COWAT Animals, p = 0.014) and attention/executive function (Trails A, p=0.049 and Trails B, p = 0.011) compared to the unilateral group. CONCLUSIONS: Unilateral STN DBS is an effective and safe treatment option for patients with advanced PD. Particularly for patients with asymmetric motor symptoms, unilateral implantation provides a meaningful improvement in motor symptoms and reductions in dopaminergic medications without the risk of neurocognitive decline seen in bilateral implantation.

Deep Brain Stimulation of Bilateral Centromedian Thalamic Nuclei in Pediatric Patients with Lennox-Gastaut Syndrome: An Institutional Experience

IntroductionSurgical management of pediatric patients with non-lesional, drug-resistant epilepsy (DRE), including patients with Lennox-Gastaut Syndrome (LGS), remains a challenge given the lack of resective targets in most patients, and demonstrates seizure freedom rates <50% at 5-years. The efficacy of deep brain stimulation (DBS) is less certain in children than adults. This study examined clinical and seizure outcomes for pediatric patients with LGS undergoing DBS targeting of the centromedian thalamic nuclei (CMTN). MethodsIRB-approved retrospective analysis of patients ≤19-years with clinical diagnosis of LGS undergoing bilateral DBS placement to the CMTN from 2020-2021 by a single surgeon. ResultsFour females and 2 males, aged 6-19 years were identified. Before surgery, each child experienced at least 6-years of refractory seizures; 4 children experienced seizures since infancy. All took antiseizure medications at time of surgery. Five children had prior placement of a vagus nerve stimulator, 2 had previous corpus callosotomy. Mean length of stay following DBS was 2-days. No children experienced adverse neurological effects from implantation; mean follow-up time was 16.3 months. Four patients had >60% reduction in seizure frequency following surgery, 1 patient experienced 10% reduction, 1 patient demonstrated no change. No children reported worsening seizure symptoms post-surgery. ConclusionsOur study contributes to the sparse literature describing CMTN DBS for children with DRE from LGS. Our results suggest that CMTN DBS is a safe and effective therapeutic modality that should be considered as alternative or adjuvant therapy for this challenging patient population. Further studies with larger patient populations are warranted.

Neurocognitive changes at different follow-up times after bilateral subthalamic nucleus deep brain stimulation in patients with Parkinson's disease

BackgroundBilateral deep thalamic nucleus brain stimulation (STN-DBS) surgery is often used to treat the motor symptoms of patients with Parkinson's disease. The change of neurocognitive symptoms in patients is, however, still unclear. ObjectiveWe aimed at analyzing the deterioration of neurocognitive symptoms in patients with Parkinson's disease after deep brain stimulation surgery under different follow-up times. MethodsA comprehensive literature review was conducted using Pubmed, Cochrane Library, and Web of Science to screen eligible study records, the meta-analysis was performed using an inverse variance method and a random-effects model. Additionally, the areas of analysis include five: cognition, executive function, memory capacity, and verbal fluency (phonetic fluency and semantic fluency). They were analyzed for changes at six and twelve months postoperatively compared to baseline. The Meta-analysis has been registered with PROSPERO under the registration number: CRD42022308786. ResultsIn terms of overall cognitive performance, executive function, and memory capacity, the original studies show a trend of improvement in these areas at 12 months postoperatively compared with 6 months, at variance, patients did not improve or deteriorated in phonetic fluency(d = −0.42 at both 6-month and 12-month follow-up) and semantic fluency from 6 to 12 months postoperatively. ConclusionIn terms of most neurocognitive symptoms, including cognitive ability, executive function, and learning memory capacity, bilateral STN-DBS surgery appears to be safe at relatively long follow-up times. However, postoperative phonetic and semantic fluency changes should still not be underestimated, and clinicians should pay more attention to patients' changes in both.

Impacts of Deep Brain Stimulation of the Globus Pallidus Internus on Swallowing: A Retrospective, Cross-Sectional Study.

Deep brain stimulation (DBS) is a common treatment for motor symptoms of Parkinson disease (PD), a condition associated with increased risk of dysphagia. The effect of DBS on swallowing function has not been comprehensively evaluated using gold-standard imaging techniques, particularly for globus pallidus internus (GPi) DBS. The objective of this retrospective, cross-sectional study was to identify differences in swallowing safety and timing kinematics among PD subjects with and without GPi DBS. We investigated the effects of unilateral and bilateral GPi DBS as well as the relationship between swallowing safety and DBS stimulation parameters, using retrospective analysis of videofluoroscopy recordings (71 recordings from 36 subjects) from electronic medical records. Outcomes were analyzed by surgical status (pre-surgical, unilateral DBS, bilateral DBS). The primary outcome was percent of thin-liquid bolus trials rated as unsafe, with Penetration-Aspiration Scale scores of 3 or higher. Secondary analyses included swallowing timing measures, relationships between swallowing safety and DBS stimulation parameters, and Dynamic Imaging Grade of Swallowing Toxicity ratings. Most subjects swallowed all boluses safely (19/29 in the pre-surgical, 16/26 in the unilateral DBS, and 10/16 in the bilateral DBS conditions). Swallowing safety impairment did not differ among stimulation groups. There was no main effect of stimulation condition on timing metrics, though main effects were found for sex and bolus type. Stimulation parameters were not correlated with swallowing safety. Swallowing efficiency and overall impairment did not differ among conditions. These results provide evidence that GPi DBS does not affect pharyngeal swallowing function. Further, prospective, investigations are needed.

Rescue subthalamic stimulation after unsatisfactory outcome of pallidal stimulation in Parkinson's disease: a case series and review.

Subthalamic nucleus (STN) and globus pallidus interna (GPi) are two main structures primarily targeted by deep brain stimulation (DBS) to treat advanced Parkinson's disease (PD). A subset of cases with unsatisfactory outcomes may benefit from rescue DBS surgery targeting another structure, while these patients' characteristics have not been well described and this phenomenon has not been well reviewed. This monocentric retrospective study included patients with PD, who underwent rescue STN DBS following an unsatisfactory outcome of the initial bilateral GPi DBS in a retrospective manner. A short review of the current literature was conducted to report the clinical outcome of rescue DBS surgeries. Eight patients were identified, and six of them were included in this study. The rescue STN DBS was performed 19.8 months after the initial GPi DBS. After 8.8 months from the rescue STN DBS, patients showed a significant off-medication improvement by 29.2% in motor symptoms compared to initial GPi DBS. Non-motor symptoms and the health-related quality of life were also significantly improved. Our findings suggest that the rescue STN DBS may improve off-medication motor and non-motor symptoms and quality of life in patients with failure of initial GPi DBS. The short review of the current literature showed that the target switching from GPi to STN was mainly due to poor initial outcomes and was performed by target substitution, whereas the switching from STN to GPi was mainly due to a gradual waning of benefits, long-term axial symptoms, dyskinesia, and dystonia and was performed by target addition.

Case report: Lingual dystonia symptoms treated with botulinum toxin in patients with THAP1 mutation

Background: THAP1 mutation dystonia is a known genetic cause of generalized dystonia. THAP1 mutation frequently presents with clinical features of bulbar dysfunction, including oromandibular and lingual dystonia. Patients complain of significant speech, chewing, and swallowing difficulties leading to major occupational and social disabilities. While bilateral globus pallidus internus deep brain stimulation (DBS) is powerful therapy for generalized dystonia and improves dystonia symptoms in the cervical and limb region, it may not improve speech despite multiple adjustments to the stimulation parameters. Treating lingual dystonia symptoms with oral medications is commonly unsatisfactory. Botulinum toxin injection, a potent therapy for focal forms of dystonia is currently underutilized in clinical practice for treating lingual dystonia.Cases: We present two patients with THAP1 mutation reporting lingual dystonia symptoms. The first patient did not meet the eligibility criteria for DBS therapy due to significant psychiatric symptoms. The second patient received DBS with improvements in cervical, limb, and trunk symptoms but complained of severe speech difficulties that did not improve despite multiple programming sessions. These patients were treated with botulinum toxin injections every 12 weeks for more than 3 years, with speech improvements lasting most of the cycle. For the most part they tolerated botulinum toxin without bothersome side effects. Along with the clinical histories, we present objective perceptual analysis of speech samples collected before and after botulinum toxin injections in one of the treatment cycles.Conclusion: Botulinum toxin injections that are clinically beneficial for mitigating lingual dystonia symptoms should be utilized to address symptoms of THAP1 mutation dystonia that may not be amenable to other therapies, such as the DBS.

The impact of bilateral subthalamic nucleus deep brain stimulation on dyskinesia and levodopa equivalent daily dose in advanced Parkinson’s disease

Abstract OBJECTIVE: To assess the effect of bilateral subthalamic nucleus deep brain stimulation (B/L STN DBS) on the progression of dyskinesia and the levodopa equivalent daily dose (LEDD) in advanced Parkinson’s disease (APD) patients 6 months postoperatively. METHODS: Seventeen APD patients aged 21–80 years with the minimum modified Hoen &amp; Yahr score of 2 while off medication and poor motor function underwent B/L STN DBS from January 2021 to December 2021. They were assessed preoperatively and 6 months postoperatively using the Unified dyskinesia rating scale (UDysRS) and Unified Parkinson’s Disease Rating Scale Part IV (UPDRS IV) for dyskinesia and LEDD dosage. RESULTS: Significant improvement was observed postoperatively in both UDysRS (pre-op 66.53 ± 24.59, post-op 30.88 ± 12.01; P = 0.000) and UPDRS IV (pre-op 9.24 ± 1.75, post-op 5.76 ± 1.39; P = 0.000) scores. The overall clinical improvement using UDysRS was 52.23 ± 16.23%. Each subscale of UDysRS showed significant improvement postoperatively: ON dyskinesia (pre-op 21 ± 7.7, post-op 13.76 ± 5.79; P &lt; 0.05); OFF dystonia (pre-op 8.53 ± 3.26, post-op 4.94 ± 2.70; P &lt; 0.05); impairment (face, pre-op 2.47 ± 2.52, post-op 0.29 ± 0.98, P &lt; 0.05; neck and trunk, pre-op 6.29 ± 4.55, post-op 0.59 ± 0.87, P &lt; 0.05; arms, pre-op 13.06 ± 5.86, post-op 5.76 ± 3.7, P &lt; 0.05; and legs, pre-op 7.18 ± 5.12, post-op 1.29 ± 1.57, P &lt; 0.05); and disability (pre-op 8 ± 3.46, post-op 4.24 ± 2.25; P &lt; 0.05), suggesting high clinical significance. LEDD (pre-op 673.41 ± 212.69 mg, post-op 386.82 ± 133.01 mg; P = 0.000) showed significant reduction in dosage 6 months postoperatively. LEDD reduction and dyskinesia improvement showed mild-to-moderate positive correlation (r = 0.404). CONCLUSION: B/L STN DBS helps in improving dyskinesia by reducing LEDD in APD patients.

Disbalanced recruitment of crossed and uncrossed cerebello-thalamic pathways during deep brain stimulation is predictive of delayed therapy escape in essential tremor

BackgroundThalamic deep brain stimulation (DBS) is an efficacious treatment for drug-resistant essential tremor (ET) and the dentato-rubro-thalamic tract (DRT) constitutes an important target structure. However, up to 40% of patients habituate and lose treatment efficacy over time, frequently accompanied by a stimulation-induced cerebellar syndrome. The phenomenon termed delayed therapy escape (DTE) is insufficiently understood. Our previous work showed that DTE clinically is pronounced on the non-dominant side and suggested that differential involvement of crossed versus uncrossed DRT (DRTx/DRTu) might play a role in DTE development. MethodsWe retrospectively enrolled right-handed patients under bilateral thalamic DBS >12 months for ET from a cross-sectional study. They were characterized with the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS) and Scale for the Assessment and Rating of Ataxia (SARA) scores at different timepoints. Normative fiber tractographic evaluations of crossed and uncrossed cerebellothalamic pathways and volume of activated tissue (VAT) studies together with [18F]Fluorodeoxyglucose positron emission tomography were applied. ResultsA total of 29 patients met the inclusion criteria. Favoring DRTu over DRTx in the non-dominant VAT was associated with DTE (R2 = 0.4463, p < 0.01) and ataxia (R2 = 0.2319, p < 0.01). Moreover, increasing VAT size on the right (non-dominant) side was associated at trend level with more asymmetric glucose metabolism shifting towards the right (dominant) dentate nucleus. ConclusionOur results suggest that a disbalanced recruitment of DRTu in the non-dominant VAT induces detrimental stimulation effects on the dominant cerebellar outflow (together with contralateral stimulation) leading to DTE and thus hampering the overall treatment efficacy.

A workflow for predicting radiofrequency-induced heating around bilateral deep brain stimulation electrodes in MRI.

Heating around deep brain stimulation (DBS) in magnetic resonance imaging (MRI) occurs when the time-varying electromagnetic (EM) fields induce currents in the electrodes which can generate heat and potentially cause tissue damage. Predicting the heating around the electrode contacts is important to ensure the safety of patients with DBS implants undergoing an MRI scan. We previously proposed a workflow to predict heating around DBS contacts and introduced a parameter, equivalent transimpedance, that is independent of electrode trajectories, termination, and radiofrequency (RF) excitations. The workflow performance was validated in a unilateral DBS system. To predict RF heating around the contacts of bilateral (DBS) electrodes during an MRI scan in an anthropomorphic head phantom. Bilateral electrodes were fixed in a skull phantom filled with hydroxyethyl cellulose (HEC) gel. The electrode shafts were suspended extracranially, in a head and torso phantom filled with the same gel material. The current induced on the electrode shaft was experimentally measured using an MR-based technique 3cm above the tip. A transimpedance value determined in a previous offline calibration was used to scale the shaft current and calculate the contact voltage. The voltage was assigned as a boundary condition on the electrical contacts of the electrode in a quasi-static (EM) simulation. The resulting specific absorption rate (SAR) distribution became the input for a transient thermal simulation and was used to predict the heating around the contacts. RF heating experiments were performed for eight different lead trajectories using circularly polarized (CP) excitation and two linear excitations for one trajectory. The measured temperatures for all experiments were compared with the simulated temperatures and the root-mean-squared errors (RMSE) were calculated. The RF heating around the contacts of both bilateral electrodes was predicted with ≤ 0.29°C of RMSE for 20 heating scenarios. The workflow successfully predicted the heating for different bilateral DBS trajectories and excitation patterns in an anthropomorphic head phantom.

The efficacy analysis of neurosurgical robot-assisted DBS in the treatment of elderly Parkinson's disease

Objective: To investigate the surgical efficacy of neurosurgery robot deep brain stimulation(DBS) in the treatment of elderly Parkinson's disease(PD). Methods: The clinical data of elderly patients (≥75 years) with PD who underwent neurosurgical robot-assisted DBS surgery in the Department of Neurosurgery of the General Hospital of Northern Theater Command from September 2016 to September 2022 were collected retrospectively. Operation time, electrode implantation duration, postoperative pneumocephalus volume, electrode implantation accuracy, the Tao's DBS surgery scale, perioperative complications were analyzed.The unified Parkinson's disease rating scales (UPDRS), UPDRS-Ⅲ, tremor, rigidity, bradykinesia, axial, Barthel Activities of Daily Living (ADL-Barthel), Levodopa Equivalent Daily Dose (LEDD), Montreal Cognitive Assessment (MoCA), Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale (HAMD) scores and mortality were assessed respectively before operation, 6, 12 and 24 months after operation and last follow-up. Results: A total of 25 elderly patients were enrolled, including 14 males and 11 females, aged(78.3±3.2) years. Nine patients had underlying diseases. Nine patients (36%) underwent bilateral Globus Pallidus pars Interna deep brain stimulation (GPi-DBS) and 16 patients (64%) underwent bilateral subthalamic nucleus deep brain stimulation (STN-DBS).The operation time was (1.56±0.19) hours, the electrode implantation duration was (1.01±0.19) hours, the pneumocephalus volume was 9.8(4.7, 23.3) cm3, and the electrode implantation accuracy was (0.84±0.24) mm, the Tao's DBS surgery scale was (80.2±6.2).The follow-up time [M(Q1, Q3)] was 57.3(27.9, 75.7) months. No serious complications such as intracranial hemorrhage, infection or poor wound healing occurred during the perioperative period. The improvement rate of UPDRS, UPDRS-Ⅲ, rigidity, bradykinesia, and LEDD at 6 months after surgery was significantly higher than that at 24 months after surgery and at the last follow-up (all P<0.05); the improvement rate of axial symptoms, ADL-Barthel score, and MoCA score at 6 months after surgery was significantly higher than that at the last follow-up (P<0.05). HAMD and HAMA scores showed no significant improvement during follow-up after surgery (both P>0.05). At the last follow-up, 12 patients died, with death time of (35.1±20.2) months after operation, and the death age of [M(Q1, Q3)] 80(79, 83)years. Conclusions: Robot-assisted DBS surgery for elderly patients with PD is accurate and safe, and the postoperative symptoms are significantly improved, and they can benefit from neuromodulation for long term, and the risks are controllable.

Review of the targeting accuracy of frameless and frame-based robot-assisted deep brain stimulation electrode implantation in pediatric patients using the Neurolocate module.

The Neurolocate module is a 3D frameless patient registration module that is designed for use with the Neuromate stereotactic robot. Long-term electrical stimulation of the globus pallidus internus (GPi) and subthalamic nucleus (STN) via deep brain electrode implantation is particularly successful in a select group of movement disorders in pediatric patients. This study aimed to review the targeting accuracy of deep brain stimulation (DBS) electrode implantation in a single center, comparing standard frame-based techniques to the frameless Neurolocate module. Twenty-four pediatric patients underwent implantation of bilateral DBS electrodes under general anesthesia during the period of August 2018-August 2022. All patients underwent robot-assisted stereotactic implantation of DBS electrodes using an intraoperative O-arm 3D scanner to confirm the final electrode position. These coordinates were compared with the planned entry and target, with attention to depth, radial, directional, and absolute errors, in addition to Euclidean distance (ED). The primary outcome evaluated the accuracy and safety of the Neurolocate frameless technology compared with standard frame-based techniques. Of the 24 bilateral DBS electrode implantations performed, 62.5% used Neurolocate technology: 87.5% were delivered to the GPi and the remaining 12.5% to the STN. The mean patient age was 11.0 (range 4-18) years and 70.8% were male. The median absolute errors in x-, y-, and z-axes were 0.35, 0.75, and 0.9 mm, respectively, using the Neurolocate module compared with 0.30, 0.95, and 1.1 mm using the standard frame-based technique. The median ED from the planned target to the actual electrode position with the Neurolocate module was 1.28 mm versus 1.69 mm using standard frame-based techniques. No major perioperative complications occurred. Stereotactic robot-assisted DBS implantation with the frameless Neurolocate module is safe for use in the pediatric population, showing good surgical accuracy and no inferiority to standard frame-based techniques. The Neurolocate module for robotic DBS surgery has the potential to improve surgical targeting accuracy, surgical time, patient comfort, and safety.

Subthalamic nucleus deep brain stimulation in primary Meige syndrome: motor and non-motor outcomes.

Deep brain stimulation (DBS) has emerged as a promising treatment for movement disorders. This prospective study aims to evaluate the effects of bilateral subthalamic nucleus DBS (STN-DBS) on motor and non-motor symptoms in patients with primary Meige syndrome. Thirty patients who underwent bilateral STN-DBS between April 2017 and June 2020 were included. Standardized and validated scales were utilized to assess the severity of dystonia, health-related quality of life, sleep, cognitive function and mental status at baseline and at 1 year and 3 years after neurostimulation. The Burke-Fahn-Marsden Dystonia Rating Scale movement scores showed a mean improvement of 63.0% and 66.8% at 1 year and 3 years, respectively, after neurostimulation. Similarly, the Burke-Fahn-Marsden Dystonia Rating Scale disability scores improved by 60.8% and 63.3% at the same time points. Postoperative quality of life demonstrated a significant and sustained improvement throughout the follow-up period. However, cognitive function, mental status, sleep quality and other neuropsychological functions did not change after 3 years of neurostimulation. Eight adverse events occurred in six patients, but no deaths or permanent sequelae were reported. Bilateral STN-DBS is a safe and effective alternative treatment for primary Meige syndrome, leading to improvements in motor function and quality of life. Nevertheless, it did not yield significant amelioration in cognitive, mental, sleep status and other neuropsychological functions after 3 years of neurostimulation.

Use of differential stimulation of the nucleus accumbens and anterior limb of the internal capsule to improve outcomes of obsessive-compulsive disorder.

Personalized stimulation is key to optimizing the outcomes of deep brain stimulation (DBS) for refractory obsessive-compulsive disorder (OCD). However, the contacts in a single conventional electrode cannot be programmed independently, which may affect the therapeutic efficacy of DBS for OCD. Therefore, a novel designed electrode and implantable pulse generator (IPG) that could achieve differential stimulation parameters for different contacts was implanted into the nucleus accumbens (NAc) and anterior limb of the internal capsule (ALIC) of a cohort of patients with OCD. Thirteen consecutive patients underwent bilateral DBS of the NAc-ALIC between January 2016 and May 2021. Differential stimulation of the NAc-ALIC was applied at initial activation. Primary effectiveness was assessed on the basis of change in scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) from baseline to 6-month follow-up. Full-response was defined as a 35% decrease in Y-BOCS score. Secondary effectiveness measures were the Hamilton Anxiety Rating Scale (HAMA) and Hamilton Depression Rating Scale (HAMD). The local field potential of bilateral NAc-ALIC was recorded in 4 patients who were reimplanted with a sensing IPG after battery depletion of the previous IPG. The Y-BOCS, HAMA, and HAMD scores decreased remarkably during the first 6 months of DBS. Ten of 13 patients were categorized as responders (76.9%). Differential stimulation of the NAc-ALIC was favorable to optimization of the stimulation parameters by increasing the parameter configurations. Power spectral density analysis revealed pronounced delta-alpha frequency activity in the NAc-ALIC. Phase-amplitude coupling of the NAc-ALIC showed that strong coupling is present between the phase of delta-theta and broadband gamma amplitude. These preliminary findings indicate that differential stimulation of the NAc-ALIC can improve the efficacy of DBS for OCD. Clinical trial registration no.: NCT02398318 (ClinicalTrials.gov).

Comparison of subthalamic unilateral and bilateral theta burst deep brain stimulation in Parkinson's disease.

High-frequency, conventional deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD) is usually applied bilaterally under the assumption of additive effects due to interhemispheric crosstalk. Theta burst stimulation (TBS-DBS) represents a new patterned stimulation mode with 5 Hz interburst and 200 Hz intraburst frequency, whose stimulation effects in a bilateral mode compared to unilateral are unknown. This single-center study evaluated acute motor effects of the most affected, contralateral body side in 17 PD patients with unilateral subthalamic TBS-DBS and 11 PD patients with bilateral TBS-DBS. Compared to therapy absence, both unilateral and bilateral TBS-DBS significantly improved (p < 0.05) lateralized Movement Disorder Society-Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III) scores. Bilateral TBS-DBS revealed only slight, but not significant additional effects in comparison to unilateral TBS-DBS on total lateralized motor scores, but on the subitem lower limb rigidity. These results indicate that bilateral TBS-DBS has limited additive beneficial effects compared to unilateral TBS-DBS in the short term.