Neurosurg Rev. 2024 Jul 20;47(1):342. doi: 10.1007/s10143-024-02563-1.

ABSTRACT

The use of microelectrode recording (MER) during deep brain stimulation (DBS) for Parkinson Disease is controversial. Furthermore, in asleep DBS anesthesia can impair the ability to record single-cell electric activity.The purpose of this study was to describe our surgical and anesthesiologic protocol for MER assessment during asleep subthalamic nucleus (STN) DBS and to put our findings in the context of a systematic review of the literature. Sixty-three STN electrodes were implanted in 32 patients under general anesthesia. A frameless technique using O-Arm scanning was adopted in all cases. Total intravenous anesthesia, monitored with bispectral index, was administered using a target controlled infusion of both propofol and remifentanil. A systematic review of the literature with metanalysis on MER in asleep vs awake STN DBS for Parkinson Disease was performed. In our series, MER could be reliably recorded in all cases, impacting profoundly on electrode positioning: the final position was located within 2 mm from the planned target only in 42.9% cases. Depth modification > 2 mm was necessary in 21 cases (33.3%), while in 15 cases (23.8%) a different track was used. At 1-year follow-up we observed a significant reduction in LEDD, UPDRS Part III score off-medications, and UPDRS Part III score on medications, as compared to baseline. The systematic review of the literature yielded 23 papers; adding the cases here reported, overall 1258 asleep DBS cases using MER are described. This technique was safe and effective: metanalysis showed similar, if not better, outcome of asleep vs awake patients operated using MER. MER are a useful and reliable tool during asleep STN DBS, leading to a fine tuning of electrode position in the majority of cases. Collaboration between neurosurgeon, neurophysiologist and neuroanesthesiologist is crucial, since slight modifications of sedation level can impact profoundly on MER reliability.

PMID:39031226 | DOI:10.1007/s10143-024-02563-1

J Parkinsons Dis. 2024 Jul 20. doi: 10.3233/JPD-230276. Online ahead of print.

ABSTRACT

BACKGROUND: 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).

OBJECTIVE: To identify risk factors for POD severity after DBS surgery in PD.

METHODS: 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.

RESULTS: 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).

CONCLUSIONS: 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.

PMID:39058451 | DOI:10.3233/JPD-230276

Arch Clin Neuropsychol. 2024 Aug 10:acae062. doi: 10.1093/arclin/acae062. Online ahead of print.

ABSTRACT

OBJECTIVE: The effects of stimulation frequency on verbal fluency (VF) following subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD) are not well understood. The present study examines the impact stimulation frequency has on VF following bilateral STN-DBS in PD.

METHODS: Prospective study of 38 consecutive patients with PD with low frequency STN-DBS (LFS) (n = 10) and high frequency STN-DBS (HFS) (n = 14), and a non-operated PD control group consisting of patients with fluctuating response to dopaminergic medication (n = 14) homogeneous in age, education, disease duration, and global cognitive function. Patients were evaluated on VF tasks (letter, semantic, action verbs, alternating). A one-way analysis of variance (ANOVA) was conducted to assess distinctions between groups. Pre- and post-surgical comparisons of fluencies were performed for operated groups. A mixed ANOVA was applied to the data to evaluate the interaction between treatment (HFS vs. LFS) and time (pre- vs. post-surgery). Strategy use (clustering and switching) was evaluated.

RESULTS: Semantic and letter fluency performance revealed significant differences between HFS and LFS groups. Pre- and post-surgical comparisons revealed HFS negatively affected letter, semantic, and action fluencies, but LFS had no effect on VF. No interaction effect or main effect of treatment was found. Main effect of time was significant for semantic and action fluencies indicating a decrease in postoperative fluency performance. Patients with LFS produced larger average cluster sizes than patients with HFS.

CONCLUSION: LFS may be less detrimental to VF, but these findings suggest that VF decline following STN-DBS is not caused by stimulation frequency alone.

PMID:39127889 | DOI:10.1093/arclin/acae062

World Neurosurg. 2024 Aug 2:S1878-8750(24)01337-8. doi: 10.1016/j.wneu.2024.07.196. Online ahead of print.

ABSTRACT

OBJECTIVE: Postural abnormalities are a debilitating symptom of Parkinson's disease (PD) that may require spinal intervention. Camptocormia is a unique abnormality most seen in PD, defined by a severe forward-flexion of the trunk that completely resolves when supine. The condition presents a challenge due to an undefined pathophysiology and optimal therapeutic approach in a high-risk patient population. In this study, the authors systematically reviewed the literature regarding the use of spine surgery for the treatment of camptocormia in PD.

METHODS: PubMed, Embase, Web of Science, and Cochrane Library were systematically queried for studies involving spine surgery as treatment of PD-associated camptocormia. Studies involving nonsurgical management, deep brain stimulation (DBS), non-camptocormic PD patients undergoing surgery, or were out of scope were excluded.

RESULTS: The search resulted in 5 studies, with a total of 19 PD patients with camptocormia who underwent spine surgery (73.7% female). The mean age was 69.5 years (range, 59 - 83), and mean PD duration was 69.5 months (range, 36 - 84). Out of 19 patients, 11 required surgical revision (57.9%), with an average of 0.68 revisions per patient (range, 0-2). Radiographic and patient-reported outcomes were inconsistently reported yet showed improvement. Ultimately, 18 patients were reported to have positive outcomes.

CONCLUSION: Despite an increased risk of complication and revision that is inherent to PD patients, spine surgery has been proven as a reasonable alternative that should be prospectively studied further, as 18/19 patients had favorable outcomes.

PMID:39098502 | DOI:10.1016/j.wneu.2024.07.196

Br J Neurosurg. 2024 Jul 22:1-9. doi: 10.1080/02688697.2024.2374581. Online ahead of print.

ABSTRACT

INTRODUCTION: Parkinson's disease is a common neurodegenerative disease. With an aging population, co-existent degenerative diseases of the spine in these patients will become more prevalent.

RESEARCH QUESTION: This systematic review and meta-analysis aims to establish the incidence and risk of adverse outcomes following spinal surgery in patients with Parkinson's disease. Material and Methods A literature review was carried out in order to identify studies assessing the outcomes of adult patients with Parkinson's disease undergoing spinal surgery for degenerative conditions. Studies with less than ten subjects or those assessing surgery for spinal deformity or trauma were excluded.

RESULTS: Of 74 studies identified, seven were included for meta-analysis. In the 689,578 participants, there was a significantly higher incidence, but not higher risk, of complications (0.54 95% CI [0.19-0.85] vs 0.07 95% CI [0.01-0.41]; p = 0.048) and revision surgery (0.6 95% CI [0.25-0.88] vs 0.1 95% CI [0.05-0.19]; p = 0.003) amongst patients with Parkinson's disease compared to controls. We also demonstrated a significantly lower incidence but not lower risk of clinical improvement (0.27 95% CI [0.16-0.41] vs 0.57 95% CI [0.36-0.76]; p = 0.02) after surgery in patients with Parkinson's disease. There was no difference in the incidence or risk of death following surgery.

DISCUSSION AND CONCLUSION: Spinal surgery for concomitant degenerative diseases in patients with Parkinson's disease is associated with a lower incidence of clinical improvement and a higher incidence of complications. Medical management should be optimised before an individually tailored and well-considered surgical intervention is implemented.

PMID:39037021 | DOI:10.1080/02688697.2024.2374581

Eur Neuropsychopharmacol. 2024 Jun 22;86:13. doi: 10.1016/j.euroneuro.2024.05.005. Online ahead of print.

NO ABSTRACT

PMID:38909544 | DOI:10.1016/j.euroneuro.2024.05.005

J Integr Neurosci. 2024 Jun 13;23(6):114. doi: 10.31083/j.jin2306114.

ABSTRACT

Deep brain stimulation (DBS) is a common therapy for managing Parkinson's disease (PD) in clinical practice. However, a complete understanding of its mode of action is still needed. DBS is believed to work primarily through electrical and neurochemical pathways. Furthermore, DBS has other mechanisms of action. This review explores the fundamental concepts and applications of DBS in treating PD, including its mechanisms, clinical implications, and recent research.

PMID:38940083 | DOI:10.31083/j.jin2306114

Curr Opin Neurol. 2024 Aug 1;37(4):394-399. doi: 10.1097/WCO.0000000000001278. Epub 2024 Jun 3.

ABSTRACT

PURPOSE OF REVIEW: The primary aim of this review is to describe and update the pathophysiological and relevant therapeutic strategies for freezing of gait (FoG) in patients with Parkinson's disease (PD).

RECENT FINDINGS: FoG presumably involves dysfunction of multiple cortical and subcortical components, including dopaminergic and nondopaminergic circuits. In this regard, levodopa and physical therapy represent the first-choice therapeutic options for PD patients with FoG. However, the relationship between FoG and levodopa is not fully predictable. For those patients with levodopa-resistant FoG, there is promising but still controversial data on the benefits of bilateral high-frequency transcranial magnetic stimulation and deep brain stimulation on the subthalamic nuclei, substantia nigra pars reticulata, pedunculopontine nucleus, and the Fields of Forel. On the other hand, general exercise, gait training with a treadmill, focus attention on gait training, and conventional physiotherapy have demonstrated moderate to large benefits in FoG.

SUMMARY: FOG requires different treatment strategies. The inclusion of adequate detection and prediction of FoG combined with double-blind, and statistically powered protocols are needed to improve patients' quality of life, the motor and nonmotor symptoms and societal burden associated with FoG.

PMID:38828625 | DOI:10.1097/WCO.0000000000001278

Nat Commun. 2024 May 31;15(1):4662. doi: 10.1038/s41467-024-48731-1.

ABSTRACT

Deep Brain Stimulation can improve tremor, bradykinesia, rigidity, and axial symptoms in patients with Parkinson's disease. Potentially, improving each symptom may require stimulation of different white matter tracts. Here, we study a large cohort of patients (N = 237 from five centers) to identify tracts associated with improvements in each of the four symptom domains. Tremor improvements were associated with stimulation of tracts connected to primary motor cortex and cerebellum. In contrast, axial symptoms are associated with stimulation of tracts connected to the supplementary motor cortex and brainstem. Bradykinesia and rigidity improvements are associated with the stimulation of tracts connected to the supplementary motor and premotor cortices, respectively. We introduce an algorithm that uses these symptom-response tracts to suggest optimal stimulation parameters for DBS based on individual patient's symptom profiles. Application of the algorithm illustrates that our symptom-tract library may bear potential in personalizing stimulation treatment based on the symptoms that are most burdensome in an individual patient.

PMID:38821913 | DOI:10.1038/s41467-024-48731-1

BMC Neurol. 2024 May 21;24(1):167. doi: 10.1186/s12883-024-03673-5.

ABSTRACT

BACKGROUND: Postural abnormalities (PA) are common in the advanced stages of Parkinson's disease (PD), but effective therapies are lacking. A few studies suggested that spinal cord stimulation (SCS) could be a potential therapy whereas its effect is still uncertain. We aimed to investigate whether SCS had potential for benefiting PD patients with PA.

METHODS: T8-12 SCS was operated on six PD patients with PA and all patients were followed for one year. Evaluations were made before and after SCS. Moreover, three patients were tested separately with SCS on-state and off-state to confirm the efficacy of SCS.

RESULTS: Improvements in lateral trunk flexion degree, anterior thoracolumbar flexion degree and motor function were found after SCS. The improvements diminished while SCS was turned off.

CONCLUSIONS: Lower thoracic SCS may be effective for improving PA in PD patients, but further studies are needed to confirm this conclusion.

TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1900024326, Registered on 6th July 2019; https://www.chictr.org.cn/showproj.aspx?proj=40835 .

PMID:38773417 | DOI:10.1186/s12883-024-03673-5

Arq Neuropsiquiatr. 2024 Apr;82(4):1-9. doi: 10.1055/s-0044-1786037. Epub 2024 Apr 23.

ABSTRACT

The field of neuromodulation has evolved significantly over the past decade. Developments include novel indications and innovations of hardware, software, and stimulation techniques leading to an expansion in scope and role of these techniques as powerful therapeutic interventions. In this review, which is the second part of an effort to document and integrate the basic fundamentals and recent successful developments in the field, we will focus on classic paradigms for electrode placement as well as new exploratory targets, mechanisms of neuromodulation using this technique and new developments, including focused ultrasound driven ablative procedures.

PMID:38653486 | DOI:10.1055/s-0044-1786037

Arq Neuropsiquiatr. 2024 Apr;82(4):1-9. doi: 10.1055/s-0044-1786026. Epub 2024 Apr 23.

ABSTRACT

Deep brain stimulation (DBS) is recognized as an established therapy for Parkinson's disease (PD) and other movement disorders in the light of the developments seen over the past three decades. Long-term efficacy is established for PD with documented improvement in the cardinal motor symptoms of PD and levodopa-induced complications, such as motor fluctuations and dyskinesias. Timing of patient selection is crucial to obtain optimal benefits from DBS therapy, before PD complications become irreversible. The objective of this first part review is to examine the fundamental concepts of DBS for PD in clinical practice, discussing the historical aspects, patient selection, potential effects of DBS on motor and non-motor symptoms, and the practical management of patients after surgery.

PMID:38653485 | DOI:10.1055/s-0044-1786026

Front Med (Lausanne). 2024 Apr 19;11:1381967. doi: 10.3389/fmed.2024.1381967. eCollection 2024.

ABSTRACT

INTRODUCTION: Postoperative delirium (POD) remains one of the most prevalent neuropsychiatric complications after deep brain stimulation (DBS) surgery. The fibrinogen-to-albumin ratio (FAR) has been shown to significantly correlate with the prognosis of many diseases related to inflammation. However, the association between FAR and POD remains unclear. We aimed to explore the association between POD and FAR in patients with Parkinson's disease (PD) undergoing DBS surgery.

METHODS: Patients with PD who underwent DBS surgery in our hospital were included in this retrospective study. FAR was calculated from the blood sample collected on admission. The association between baseline FAR and delirium after surgery was assessed by binary logistic regression analysis, interaction analysis, and stratified analyses.

RESULTS: Of 226 patients, 37 (16.4%) suffered from delirium after surgery. The average age of the participants was 63.3 ± 7.2 years, and 51.3% were male patients. Multivariate logistic regression analysis indicated that patients in the highest FAR tertile had a higher risk of POD compared with patients in the lowest FAR tertile (OR = 3.93, 95% CI: 1.24 ~ 12.67). Subgroup analysis demonstrated that FAR and the preoperative Mini-Mental State Examination score (p = 0.013) had an association with delirium after surgery.

CONCLUSION: Our data suggest that a higher preoperative FAR was significantly associated with delirium after DBS surgery. FAR on admission is a useful candidate biomarker to identify patients with PD who are at a high risk of delirium following DBS surgery.

PMID:38707190 | PMC:PMC11069307 | DOI:10.3389/fmed.2024.1381967

PLoS One. 2024 May 10;19(5):e0302739. doi: 10.1371/journal.pone.0302739. eCollection 2024.

ABSTRACT

BACKGROUND: 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.

OBJECTIVE: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSION: 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.

PMID:38728329 | DOI:10.1371/journal.pone.0302739

Medicine (Baltimore). 2024 Apr 26;103(17):e37955. doi: 10.1097/MD.0000000000037955.

ABSTRACT

BACKGROUND: Subthalamic nucleus deep brain stimulation (STN-DBS) is a viable therapeutic for advanced Parkinson's disease. However, the efficacy and safety of STN-DBS under local anesthesia (LA) versus general anesthesia (GA) remain controversial. This meta-analysis aims to compare them using an expanded sample size.

METHODS: The databases of Embase, Cochrane Library and Medline were systematically searched for eligible cohort studies published between 1967 and 2023. Clinical efficacy was assessed using either Unified Parkinson's Disease Rating Scale (UPDRS) section III scores or levodopa equivalent dosage requirements. Subgroup analyses were performed to assess complications (adverse effects related to stimulation, general neurological and surgical complications, and hardware-related complications).

RESULTS: Fifteen studies, comprising of 13 retrospective cohort studies and 2 prospective cohort studies, involving a total of 943 patients were included in this meta-analysis. The results indicate that there were no significant differences between the 2 groups with regards to improvement in UPDRS III score or postoperative levodopa equivalent dosage requirement. However, subgroup analysis revealed that patients who underwent GA with intraoperative imaging had higher UPDRS III score improvement compared to those who received LA with microelectrode recording (MER) (P = .03). No significant difference was found in the improvement of UPDRS III scores between the GA group and LA group with MER. Additionally, there were no notable differences in the incidence rates of complications between these 2 groups.

CONCLUSIONS: Our meta-analysis indicates that STN-DBS performed under GA or LA have similar clinical outcomes and complications. Therefore, GA may be a suitable option for patients with severe symptoms who cannot tolerate the procedure under LA. Additionally, the GA group with intraoperative imaging showed better clinical outcomes than the LA group with MER. A more compelling conclusion would require larger prospective cohort studies with a substantial patient population and extended long follow-up to validate.

PMID:38669414 | DOI:10.1097/MD.0000000000037955

Stereotact Funct Neurosurg. 2024 Apr 18:1-15. doi: 10.1159/000536310. Online ahead of print.

ABSTRACT

INTRODUCTION: Deep brain stimulation (DBS) is a well-established surgical therapy for patients with Parkinsons' Disease (PD). Traditionally, DBS surgery for PD is performed under local anesthesia, whereby the patient is awake to facilitate intraoperative neurophysiological confirmation of the intended target using microelectrode recordings. General anesthesia allows for improved patient comfort without sacrificing anatomic precision and clinical outcomes.

METHODS: We performed a systemic review and meta-analysis on patients undergoing DBS for PD. Published randomized controlled trials, prospective and retrospective studies, and case series which compared asleep and awake techniques for patients undergoing DBS for PD were included. A total of 19 studies and 1,900 patients were included in the analysis.

RESULTS: We analyzed the (i) clinical effectiveness - postoperative UPDRS III score, levodopa equivalent daily doses and DBS stimulation requirements. (ii) Surgical and anesthesia related complications, number of lead insertions and operative time (iii) patient's quality of life, mood and cognitive measures using PDQ-39, MDRS, and MMSE scores. There was no significant difference in results between the awake and asleep groups, other than for operative time, for which there was significant heterogeneity.

CONCLUSION: With the advent of newer technology, there is likely to have narrowing differences in outcomes between awake or asleep DBS. What would therefore be more important would be to consider the patient's comfort and clinical status as well as the operative team's familiarity with the procedure to ensure seamless transition and care.

PMID:38636468 | DOI:10.1159/000536310

J Clin Neurosci. 2024 Apr 10;123:196-202. doi: 10.1016/j.jocn.2024.03.033. Online ahead of print.

ABSTRACT

BACKGROUND: Patients with Parkinson's Disease (PD) who receive either asleep image-guided subthalamic nucleus deep brain stimulation (DBS) or the traditional awake technique have comparable motor outcomes. However, there are fewer studies regarding which technique should be chosen for globus pallidus internus (GPi) DBS. This systematic review and meta-analysis aims to compare the accuracy of lead placement and motor outcomes of asleep versus awake GPi DBS PD population.

METHODS: We systematically searched PubMed, Embase, and Cochrane for studies comparing asleep vs. awake GPi DBS lead placement in patients with PD. Outcomes were spatial accuracy of lead placement, measured by radial error between intended and actual location, motor improvement measured using (UPDRS III), and postoperative stimulation parameters. Statistical analysis was performed with Review Manager 5.1.7. and OpenMeta [Analyst].

RESULTS: Three studies met inclusion criteria with a total of 247 patients. Asleep DBS was used to treat 192 (77.7 %) patients. Follow-up ranged from 6 to 48 months. Radial error was not statistically different between groups (MD -0.49 mm; 95 % CI -1.0 to 0.02; I² = 86 %; p = 0.06), with a tendency for higher target accuracy with the asleep technique. There was no significant difference between groups in change on motor function, as measured by UPDRS III, from pre- to postoperative (MD 8.30 %; 95 % CI -4.78 to 21.37; I² = 67 %, p = 0.2). There was a significant difference in postoperative stimulation voltage, with the asleep group requiring less voltage than the awake group (MD -0.27 V; 95 % CI -0.46 to - 0.08; I² = 0 %; p = 0.006).

CONCLUSION: Our meta-analysis indicates that asleep image-guided GPi DBS presents a statistical tendency suggesting superior target accuracy when compared with the awake standard technique. Differences in change in motor function were not statistically significant between groups.

PMID:38604023 | DOI:10.1016/j.jocn.2024.03.033

Neuromodulation. 2024 Apr;27(3):565-571. doi: 10.1016/j.neurom.2023.08.004. Epub 2023 Oct 5.

ABSTRACT

OBJECTIVES: Deep brain stimulation (DBS) is a well-established surgical therapy for movement disorders that comprises implantation of stimulation electrodes and a pacemaker. These procedures can be performed separately, leaving the possibility of externalizing the electrodes for local field potential recording or testing multiple targets for therapeutic efficacy. It is still debated whether the temporary externalization of DBS electrodes leads to an increased risk of infection. We therefore aimed to assess the risk of infection during and after lead externalization in DBS surgery.

MATERIALS AND METHODS: In this retrospective study, we analyzed a consecutive series of 624 DBS surgeries, including 266 instances with temporary externalization of DBS electrodes for a mean of 6.1 days. Patients were available for follow-up of at least one year, except in 15 instances. In 14 patients with negative test stimulation, electrodes were removed. All kinds of infections related to implantation of the neurostimulation system were accounted for.

RESULTS: Overall, infections occurred in 22 of 624 surgeries (3.5%). Without externalization of electrodes, infections were noted after 7 of 358 surgeries (2.0%), whereas with externalization, 15 of 252 infections were found (6.0%). This difference was significant (p = 0.01), but it did not reach statistical significance when comparing groups within different diagnoses. The rate of infection with externalized electrodes was highest in psychiatric disorders (9.1%), followed by Parkinson's disease (7.3%), pain (5.7%), and dystonia (5.5%). The duration of the externalization of the DBS electrodes was comparable in patients who developed an infection (6.1 ± 3.1 days) with duration in those who did not (6.0 ± 3.5 days).

CONCLUSIONS: Although infection rates were relatively low in our study, there was a slightly higher infection rate when DBS electrodes were externalized. On the basis of our results, the indication for electrode externalization should be carefully considered, and patients should be informed about the possibility of a higher infection risk when externalization of DBS electrodes is planned.

PMID:37804281 | DOI:10.1016/j.neurom.2023.08.004

Mov Disord. 2024 Feb;39(2):235-248. doi: 10.1002/mds.29700. Epub 2024 Jan 17.

ABSTRACT

BACKGROUND: Impulse-control and related behavioral disorders (ICBDs) significantly impact the lives of Parkinson's disease (PD) patients and caregivers, with lasting consequences if undiagnosed and untreated. While ICBD pathophysiology and risk factors are well-studied, a standardized severity definition and treatment evidence remain elusive.

OBJECTIVE: This work aimed to establish international expert consensus on ICBD treatment strategies. To comprehensively address diverse treatment availabilities, experts from various continents were included.

METHODS: From 2021 to 2023, global movement disorders specialists engaged in a Delphi process. A core expert group initiated surveys, involving a larger panel in three iterations, leading to refined severity definitions and treatment pathways.

RESULTS: Experts achieved consensus on defining ICBD severity, emphasizing regular PD patient screenings for early detection. General treatment recommendations focused on continuous monitoring, collaboration with significant others, and seeking specialist advice for legal or financial challenges. For mild to severe ICBDs, gradual reduction in dopamine agonists was endorsed, followed by reductions in other PD medications. Second-line treatment strategies included diverse approaches like reversing the last medication change, cognitive behavior therapy, subthalamic nucleus deep brain stimulation, and specific medications like quetiapine, clozapine, and antidepressants. The panel reached consensus on distinct treatment pathways for punding and dopamine dysregulation syndrome, formulating therapy recommendations. Comprehensive discussions addressed management strategies for the exacerbation of either motor or non-motor symptoms following the proposed treatments.

CONCLUSION: The consensus offers in-depth insights into ICBD management, presenting clear severity criteria and expert consensus treatment recommendations. The study highlights the critical need for further research to enhance ICBD management. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

PMID:38234035 | DOI:10.1002/mds.29700

Neurobiol Dis. 2024 Jan;190:106384. doi: 10.1016/j.nbd.2023.106384. Epub 2023 Dec 20.

ABSTRACT

External sensory cues can reduce freezing of gait in people with Parkinson's disease (PD), yet the role of the basal ganglia in these movements is unclear. We used microelectrode recordings to examine modulations in single unit (SU) and oscillatory local field potentials (LFP) during auditory-cued rhythmic pedaling movements of the feet. We tested five blocks of increasing cue frequencies (1 Hz, 1.5 Hz, 2 Hz, 2.5 Hz, and 3 Hz) in 24 people with PD undergoing deep brain stimulation surgery of the subthalamic nucleus (STN) or globus pallidus internus (GPi). Single unit firing and beta band LFPs (13-30 Hz) in response to movement onsets or cue onsets were examined. We found that the timing accuracy of foot pedaling decreased with faster cue frequencies. Increasing cue frequencies also attenuated firing rates in both STN and GPi neurons. Peak beta power in the GPi and STN showed different responses to the task. GPi beta power showed persistent suppression with fast cues and phasic modulation with slow cues. STN beta power showed enhanced beta synchronization following movement. STN beta power also correlated with rate of pedaling. Overall, we showed task-related responses in the GPi and STN during auditory-cued movements with differential roles in sensory and motor control. The results suggest a role for both input and output basal ganglia nuclei in auditory rhythmic pacing of gait-like movements in PD.

PMID:38135193 | DOI:10.1016/j.nbd.2023.106384