Risk of Deep Venous Thrombosis in Patients With Parkinson’s Disease: A Meta‑Analysis of Observational Studies

Title: Risk of Deep Venous Thrombosis in Patients With Parkinson’s Disease: A Meta‑Analysis of Observational Studies

Authors: Vishnu V. Byroju, Jamir Pitton Rissardo, Jorge Patino, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To compare the risk of deep venous thrombosis (DVT) in patients with Parkinson’s disease (PD) versus non‑PD.

Background

Patients with PD may have an elevated DVT risk due to immobility, autonomic dysfunction, and reduced muscle pumping. However, evidence has been inconsistent across surgical and nonsurgical populations.

Design/Methods

PubMed‑indexed studies reporting DVT incidence in PD versus non‑PD patients were screened. Risk ratios (RRs) were pooled using Mantel‑Haenszel (fixed) and REML (random effects) models. Subgroup analyses included study design, geographic region, and surgery type.

Results

Across 16 studies comprising 819,514 patients, 2,176 DVT events occurred. PD patients demonstrated a significantly higher risk of DVT compared with non‑PD controls (random‑effects RR 2.23, 95% CI 1.41–3.53). Heterogeneity was moderate to high (I² = 67%). Subgroup analyses showed elevated risk in cohort studies (RR 1.37, 95% CI 1.10–1.71) and cross‑sectional studies (RR 6.82, 95% CI 4.05–11.48), while case‑control studies demonstrated a non‑significant association (RR 1.44, 95% CI 0.90–2.31)[Figure 1]. Regionally, the highest risk was observed in Asian studies (RR 6.04, 95% CI 3.26–11.19), followed by North America (RR 1.71, 95% CI 1.08–2.71). Associations from Europe (RR 2.41, 95% CI 0.30–19.15) and Australia (RR 3.49, 95% CI 0.38–32.32) were not statistically significant [Figure 2]. By surgical category, nonsurgical cohorts demonstrated the greatest risk (RR 6.07, 95% CI 3.20–11.49), followed by spine surgery (RR 2.45, 95% CI 1.19–5.04) and orthopedic procedures (RR 1.29, 95% CI 1.01–1.63). No significant increase in risk was observed for DBS surgery (RR 2.27, 95% CI 0.12–41.75) or mixed surgical groups [Figure 3].

Conclusions

PD is associated with a significantly increased risk of DVT across study types and clinical settings. The magnitude of risk varies by geography and surgical context, suggesting that underlying population and perioperative factors are at play.

Citation

Byroju V, Rissardo JP, Patino J, Caprara AL, McGarry A, Walker I. Risk of Deep Venous Thrombosis in Patients With Parkinson’s Disease: A Meta‑Analysis of Observational Studies. Mov Disord 2026;41(Suppl_1):S758-S761.

Figure 1. DVT risk in PD across study designs.

Figure 2. DVT risk in PD across regions.

Figure 3. DVT risk in PD across surgery type.

Antidepressants in Huntington’s Disease: A Meta Analysis of Mood and Motor Outcomes with Placebo-controlled Trials

Title: Antidepressants in Huntington’s Disease: A Meta Analysis of Mood and Motor Outcomes with Placebo-controlled Trials

Authors: Jorge Patino, Jamir Pitton Rissardo, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker, N. Rocha, Andrew Duker, and Erin Furr Stimming

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the antidepressant efficacy for depression in Huntington’s disease (HD).

Background

Depression is highly prevalent in HD. Despite frequent clinical use of antidepressants, evidence from trials remains limited and fragmented. A consolidated analysis of available trials data is needed to guide treatment decisions.

Design/Methods

PubMed was searched for trials evaluating antidepressant drugs in HD. The primary endpoint was depression (HAM‑D). Secondary endpoints included anxiety (SAS), motor function (UHDRS‑TMS), cognition (MMSE, NPI), functional capacity (UHDRS‑TFC), executive function (Trails‑B), and adverse events. Mean differences (MDs) were synthesized using inverse‑variance models, and SMD with REML.

Results

A total of 4 trials studying fluoxetine, venlafaxine, citalopram, and bupropion were found. For bupropion, only data about side effects were available. Antidepressants significantly improved depression versus control (MD −4.52, 95% CI −8.85 to −0.20; I² = 86%) [Figure 1]. Subgroup effects varied by medication (fluoxetine MD −2.87; venlafaxine MD −9.08; citalopram MD −1.90). Anxiety improved modestly (SMD −0.62, 95% CI −1.17 to −0.08) [Figure 2]. No significant effects were observed for functional (MD –0.27, 95% CI –1.37 to 0.82) [Figure 3], executive (SMD -0.12, 95% CI –1.11 to 0.88), motor (SMD –0.37, 95% CI –0.91 to 0.17), or cognitive (SMD –0.21, 95% CI –0.75 to 0.32) outcomes. Adverse event rates were similar between antidepressant and placebo groups (RR 1.86, 95% CI 0.73–4.75). Agitation (RR 0.71, 95% CI 0.17–3.01), hypomania (RR 0.95, 95% CI 0.25–3.65), fatigue (RR 0.31, 95% CI 0.01–6.85), and weight loss (RR 2.77, 95% CI 0.12–61.65) occurred at comparable frequencies.

Conclusions

Evidence indicates antidepressants yield a modest yet significant reduction in depressive symptoms in HD, though effects differ by drug class. Benefits seem confined to mood outcomes, with no consistent improvement in motor, cognitive, or functional measures. Larger, adequately powered trials are needed to guide optimal treatment strategies.

Citation

Patino J, Rissardo JP, Caprara AL, McGarry A, Walker I, Rocha N, Duker A, Furr Stimming E. Antidepressants in Huntington’s Disease: A Meta Analysis of Mood and Motor Outcomes with Placebo-controlled Trials. Mov Disord 2026;41(Suppl_1):S433-S434.

Figure 1. Forest plot of pooled MD of depressive outcomes.

Figure 2. Forest plot of pooled MD of anxiety outcomes.

Figure 3. Forest plot of pooled MD of functional capacity outcomes.

Efficacy of Vitamin C for Restless Legs Syndrome: A Systematic Review and Meta‑analysis of Randomized Controlled Trials

Title: Efficacy of Vitamin C for Restless Legs Syndrome: A Systematic Review and Meta‑analysis of Randomized Controlled Trials

Authors: Ana Leticia Fornari Caprara, Jamir Pitton Rissardo, Jorge Patino, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the efficacy and safety of vitamin C (VITC) for treating restless legs syndrome (RLS) using evidence exclusively from randomized controlled trials (RCTs).

Background

VITC has been proposed as a potential therapy for RLS due to its antioxidant properties and possible modulation of dopaminergic pathways. Several RCTs have assessed its impact on symptom severity and related clinical outcomes, but findings have been inconsistent.

Design/Methods

A systematic review of PubMed and Google Scholar of RCTs comparing VITC to placebo or active comparators in adults with RLS was conducted. The primary outcome was change in International Restless Legs Scale (IRLS) scores. Secondary outcomes included itching, categorical RLS symptom severity, and sleep disturbance. Adverse events such as nausea and dyspepsia were also investigated. Random‑ and fixed‑effects models were applied. Heterogeneity was quantified using I².

Results

Four RCT arms from two studies contributed to the IRLS analysis (n=119). In subgroup analysis, VITC was significantly more effective than placebo (MD –8.12 points; 95% CI –11.52 to –4.71; p<0.001), while demonstrating no meaningful difference compared with vitamin E (MD 0.10; 95% CI –3.42 to 3.62) or pramipexole (MD 0.59; 95% CI –4.18 to 5.36) [Figure 1]. VITC also improved sleep outcomes (RD 0.36; 95% CI 0.17 to 0.54; p<0.001). However, effects on itching (RR 0.82; 95% CI 0.18–3.75) and global RLS severity (RR 0.80; 95% CI 0.20–3.31) varied substantially across subgroups, reflecting heterogeneity in clinical response. Nausea (RR 0.32; 95% CI 0.04–2.94) [Figure 2] and dyspepsia (RR 3.00; 95% CI 0.33–27.33) [Figure 3] remained infrequent adverse events and did not differ significantly between treatment groups.

Conclusions

VITC may reduce RLS severity compared with placebo, though benefits are inconsistent across comparators and limited by high heterogeneity. Evidence for secondary outcomes is mixed and largely derived from single‑study data. Larger, rigorously designed RCTs are needed to clarify VITC’s therapeutic role in RLS.

Citation

Caprara AL, Rissardo JP, Patino J, McGarry A, Walker I. Efficacy of Vitamin C for Restless Legs Syndrome: A Systematic Review and Meta‑analysis of Randomized Controlled Trials. Mov Disord 2026;41(Suppl_1):S448-S449.

Figure 1. Forest plot of pooled MD of IRLS.

Figure 2. Forest plot of pooled RR of nausea.

Figure 3. Forest plot of pooled RR of dispepsia.

Efficacy and Safety of Mesdopetam (IRL790) for Levodopa Induced Dyskinesia in Parkinson’s Disease: A Meta analysis of Randomized Controlled Trials

Title: Efficacy and Safety of Mesdopetam (IRL790) for Levodopa Induced Dyskinesia in Parkinson’s Disease: A Meta analysis of Randomized Controlled Trials

Authors: Ashwin Achuthaprasad, Jamir Pitton Rissardo, Jorge Patino, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the efficacy and safety of mesdopetam compared with placebo for levodopa‑induced dyskinesia (LID) in Parkinson’s disease (PD).

Background

Mesdopetam (IRL790) is a selective dopamine D3‑receptor antagonist developed to reduce LID without worsening parkinsonism. Multiple randomized trials have investigated its clinical effects across different dose ranges, but results have varied.

Design/Methods

A meta‑analysis of randomized, double‑blind, placebo‑controlled trials was conducted using studies registered on ClinicalTrials.gov to ensure methodological rigor and consistency. Outcomes extracted included the UDysRS total score, ON-time without troublesome dyskinesia (hours), OFF time (hours), MDS-UPDRS‑IV, activities of daily living (MDS-UPDRS‑II), and adverse events (AEs). Mean differences (MD), standardized mean differences (SMD), and risk ratios (RR) for dichotomous outcomes were pooled using inverse‑variance statistical models.

Results

Across 3 studies (n = 323), mesdopetam was non-significant for dyskinesia severity reduction (MD –1.77 points, 95% CI –4.07 to 0.54) [Figure 1]. ON-time without troublesome dyskinesia improvement was nonsignificant (MD –0.47 h, 95% CI –1.25 to 0.31) [Figure 2]. OFF time decreased significantly (MD –0.61 h, 95% CI –1.16 to –0.07) [Figure 3]. UPDRS-IV (MD –0.15 points, 95% CI –0.37 to 0.07) and activities of daily living (SMD –0.17, 95% CI –0.39 to 0.06) were not significant. Overall, any AEs (RR 1.12, 95% CI 0.94–1.34), serious AEs (RR 0.45, 95% CI 0.14–1.42), and falls (RR 1.09, 95% CI 0.45–2.59) were comparable between groups. Fatigue occurred less frequently with mesdopetam, showing a protective effect (RR 0.23, 95% CI 0.06–0.81).

Conclusions

Mesdopetam appears safe and modestly effective for LID, with small improvements in dyskinesia severity and OFF time and no worsening of motor disability. Larger trials are warranted to clarify optimal dosing and confirm clinical benefit.

Citation

Achuthaprasad A, Rissardo JP, Patino J, Caprara AL, McGarry A, Walker I. Efficacy and Safety of Mesdopetam (IRL790) for Levodopa Induced Dyskinesia in Parkinson’s Disease: A Meta analysis of Randomized Controlled Trials. Mov Disord 2026;41(Suppl_1):S1204-S1205.

Figure 1. Forest plot of pooled MD of UDysRS total score.

Figure 2. Forest plot of pooled MD of ON-time without troublesome dyskinesia.

Figure 3. Forest plot of pooled MD of OFF-time.

Abstracts - 2027

2027

NANS 2027 Annual Meeting - Las Vegas, NV

Motor Outcomes After Deep Brain Stimulation in GBA vs Non‑GBA Parkinson’s Disease: A Meta‑analysis

Medication-State–Specific Effects of Deep Brain Stimulation on Freezing of Gait in Parkinson’s Disease

Deep Brain Stimulation of the Anterior Limb of the Internal Capsule for Obsessive–Compulsive Disorder

Awake Versus Asleep Deep Brain Stimulation for Parkinson’s Disease: A Meta‑Analysis of Motor Outcomes

Robotics‑Assisted Versus Conventional Techniques in Deep Brain Stimulation: A Systematic Review and Meta‑analysis

Change in Olfactory Function Following Deep Brain Stimulation: A Systematic Review and Meta‑Analysis

Efficacy and Neuropsychiatric Outcomes of Deep Brain Stimulation in Meige Syndrome: A Meta‑Analysis

Diagnostic Performance of Algorithm-Based Targeting in Deep Brain Stimulation for Parkinson’s Disease: A Systematic Review and Meta-analysis

Effect of Deep Brain Stimulation on Sexual Function in Parkinson’s Disease: A Systematic Review and Meta‑Analysis

Effects of Deep Brain Stimulation on Gait Velocity in Parkinson’s Disease: A Meta‑analysis

Speech and Voice Outcomes Following Subthalamic Versus Pallidal Deep Brain Stimulation for Parkinson Disease

Optimization of deep brain stimulation programming for speech impairment in Parkinson disease

Sacral Neuromodulation and Urinary Outcomes in Parkinson Disease: A Multicenter Propensity-Matched Cohort Study

Sacral Neuromodulation and Urinary Complications in Multiple Sclerosis: A Propensity-Matched Multicenter Cohort Study

RNS in Multifocal Epilepsy After Failed Resection: A Bilateral Depth‑Electrode Approach in Complex Drug-Resistant Epilepsy

Stereo-EEG Guided Radiofrequency Thermocoagulation for Drug-Resistant Temporal Lobe Epilepsy in a Patient with Prior Lobectomy

Sequential Neuromodulation and Adjunctive Fenfluramine Therapy in Drug-Resistant Epilepsy: A Multimodal Treatment Paradigm

Optimization of Anterior Nucleus of the Thalamus Deep Brain Stimulation in Refractory Focal Epilepsy With Persistent Amnesia

A Meta-analysis of Tonic Motor Activation (TOMAC) Therapy for Restless Legs Syndrome

Title: A Meta-analysis of Tonic Motor Activation (TOMAC) Therapy for Restless Legs Syndrome

Authors: Jamir Pitton Rissardo, Jorge Patino, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the efficacy and safety of Tonic Motor Activation (TOMAC) therapy for adults with restless legs syndrome (RLS).

Background

TOMAC is a novel, wearable neuromodulation therapy designed to activate peripheral motor pathways and reduce sensorimotor symptoms in RLS. Individual trials have reported symptomatic improvement, particularly in treatment‑refractory patients, yet a comprehensive quantitative synthesis has been lacking.

Design/Methods

A meta‑analysis was performed using data extracted from PubMed‑indexed TOMAC randomized controlled trials. Primary outcomes included change in International RLS Rating Scale (IRLS) scores and responder rates on the Clinical Global Impression–Improvement (CGI‑I) and Patient Global Impression–Improvement (PGI‑I). Secondary outcomes included MOS‑I/MOS‑II sleep scales and adverse events. Analyses used inverse‑variance fixed and random‑effects models.

Results

IRLS comparisons (n=345; TOMAC=166, control=179) demonstrated significant improvement with TOMAC versus control (MD −4.06, 95% CI −4.68 to −3.44; p<0.001) with no observed heterogeneity (I²=0%) [Figure 1]. Subgroup analyses showed consistent benefit in both treatment‑naive (MD −4.57) and treatment‑refractory (MD −3.83) cohorts. Sleep outcomes (MOS‑I and MOS‑II) also favored TOMAC [MD −9.50 (95% CI −13.04 to −5.95) and MD −10.26 (95% CI −13.77 to −6.74), respectively] [Figure 2] [Figure 3]. TOMAC significantly increased clinical responder rates on CGI‑I (RR 3.89, CI 2.59–5.86) and PGI‑I (RR 3.28, CI 2.25–4.80). Adverse events were more common with TOMAC (RR 1.93, CI 1.45–2.57), predominantly mild device‑related sensations like discomfort (RR 2.11, CI 1.17–3.82); while skin changes (RR 0.99, CI 0.36–2.72) occurred at similar rates in TOMAC and sham. Discontinuation rates remained low and comparable to control (RR 2.50, CI 0.80–7.83), regardless of whether events were considered device‑related (RR 3.00, CI 0.32–28.10).

Conclusions

TOMAC therapy demonstrates clinically meaningful improvements in RLS symptom severity, sleep quality, and patient‑reported outcomes, with consistent effects across naive and refractory populations. Although mild device‑related adverse events are more frequent, overall tolerability is favorable.

Citation

Rissardo JP, Patino J, Caprara AL, McGarry A, Walker I. A Meta-analysis of Tonic Motor Activation (TOMAC) Therapy for Restless Legs Syndrome. Mov Disord 2026;41(Suppl_1):S449-S450.

Figure 1. Forest plot of pooled MD of IRLS.

Figure 2. Forest plot of pooled MD of MOS-I.

Figure 3. Forest plot of pooled MD of MOS-II.

Efficacy and Safety of Ecopipam for Tourette Syndrome: A Meta‑analysis of Controlled Trials

Title: Efficacy and Safety of Ecopipam for Tourette Syndrome: A Meta‑analysis of Controlled Trials

Authors: Ashwin Achuthaprasad, Jamir Pitton Rissardo, Jorge Patino, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the efficacy and safety of ecopipam for tic reduction in Tourette syndrome (TS).

Background

Ecopipam, a selective dopamine D1 receptor antagonist, has emerged as a promising non‑D2‑blocking therapy for TS. Multiple clinical trials have examined its effects on tic severity and psychiatric comorbidities, but results have not been collectively summarized.

Design/Methods

A meta‑analytic synthesis was performed using data from PubMed trials. Outcomes included Yale Global Tic Severity Scale–Total Tic Score (YGTSS‑TTS), Clinical Global Impression–Severity (CGI‑S), and measures of depression (HAM-D, CDI, CDRS) and obsessive‑compulsive symptoms (Y-BOCS, CY-BOCS). Safety outcomes included serious (SAEs) and non‑SAEs. Mean differences (MD), standardized mean differences (SMD), and risk ratios (RR) were calculated using inverse‑variance and Mantel‑Haenszel methods.

Results

Across four trials (n=392), ecopipam significantly reduced YGTSS‑TTS versus placebo (MD −8.59; 95% CI −12.19 to −4.98) [Figure 1]. CGI‑S scores also improved (MD −0.92; 95% CI −1.08 to −0.76) [Figure 2]. Depression scores showed a small but significant benefit (SMD −0.21; 95% CI −0.39 to −0.02) [Figure 3], while obsessive‑compulsive symptom changes were not significant (SMD −0.12; 95% CI −0.36 to 0.12). SAEs were rare and did not differ from placebo (RR 1.18; 95% CI 0.41–3.45). Non‑SAEs were comparable between groups (RR 1.14; 95% CI 0.89–1.46). Insomnia (RR 2.46; 95% CI 0.37–16.14), fatigue (RR 3.26; 95% CI 0.42–25.10), and headache (RR 1.43; 95% CI 0.66–3.08) also did not differ from placebo.

Conclusions

Ecopipam demonstrates consistent, clinically meaningful reductions in tic severity, with a favorable safety profile and minimal risk of dopaminergic adverse effects. Improvements in global severity and depressive symptoms further support its therapeutic potential. These findings highlight ecopipam as a promising non‑D2‑blocking treatment option for TS, warranting continued investigation in larger, long‑term trials.

Citation

Achuthaprasad A, Rissardo JP, Patino J, Caprara AL, McGarry A, Walker I. Efficacy and Safety of Ecopipam for Tourette Syndrome: A Meta analysis of Controlled Trials. Mov Disord 2026;41(Suppl_1):S437-S438.

Figure 1. Forest plot of pooled MD of YGTSS‑TTS.

Figure 2. Forest plot of pooled MD of CGI-C response.

Figure 3. Forest plot of pooled SMD of depressive outcomes.

Ketogenic Diet and Motor Outcomes in Parkinson’s Disease: A Meta-analysis of Randomized Trials

Title: Ketogenic Diet and Motor Outcomes in Parkinson’s Disease: A Meta-analysis of Randomized Trials

Authors: Ana Leticia Fornari Caprara, Jamir Pitton Rissardo, Jorge Patino, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the effects of ketogenic diet (KD) interventions on motor outcomes and adverse events in Parkinson’s disease (PD).

Background

Metabolic therapies such as KD have been proposed to improve mitochondrial efficiency and reduce oxidative stress in PD, potentially improving motor symptoms; however, existing trials report variable results and lack consensus on clinical impact and safety.

Design/Methods

A meta-analysis of PubMed-indexed randomized controlled trials evaluating KD in PD was performed. Extracted data included MDS-UPDRS-III and MDS-UPDRS-II in the ON state, weight, metabolic biomarkers, and adverse event risks. Effect sizes were calculated as mean differences (MD) or relative risks (RR) using inverse-variance and Mantel-Haenszel methods, applying random-effects models when appropriate.

Results

Five trials involving 129 participants were analyzed. KD did not significantly improve MDS-UPDRS-III (MD 0.97, 95% CI −1.99 to 3.92) [Figure 1] or MDS-UPDRS-II (MD −1.45, 95% CI −3.12 to 0.23) [Figure 2]. No consistent effects were observed for weight (MD 0.19, 95% CI −1.34 to 1.72) [Figure 3], glucose (MD 0.54, 95% CI −0.02 to 1.10), or triglycerides (MD 0.15, 95% CI −0.24 to 0.55). A significant reduction in A1c (MD −0.33, 95% CI −0.61 to −0.05) and an increase in total cholesterol (MD 1.57, 95% CI 1.19 to 1.95) were observed. Adverse event rates were comparable between KD and control groups, with nonsignificant relative risks for constipation (RR 3.80, 95% CI 0.18–80.57), fatigue (RR 0.73, 95% CI 0.10–5.22), and dizziness (RR 0.88, 95% CI 0.14–5.60).

Conclusions

KD did not produce significant improvements in motor function. Metabolic effects were minimal, and adverse events were comparable to controls. Larger, longer-duration studies are needed to clarify the therapeutic role of KD in PD.

Citation

Caprara AL, Rissardo JP, Patino J, McGarry A, Walker I. Ketogenic Diet and Motor Outcomes in Parkinson’s Disease: A Meta-analysis of Randomized Trials. Mov Disord 2026;41(Suppl_1): S1211-S1213.

Figure 1. Forest plot of pooled MD of motor outcomes.

Figure 2. Forest plot of pooled MD of UPDRS-II.

Figure 3. Forest plot of pooled MD of weight change.

Motor and Quality‑of‑Life Outcomes After MR‑Guided Focused Ultrasound Subthalamotomy for Parkinson’s Disease: A Meta‑analysis

Title: Motor and Quality‑of‑Life Outcomes After MR‑Guided Focused Ultrasound Subthalamotomy for Parkinson’s Disease: A Meta‑analysis

Authors: Ashwin Achuthaprasad, Jamir Pitton Rissardo, Jorge Patino, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the efficacy and safety of MR‑guided focused ultrasound (MRgFUS) subthalamotomy for improving motor symptoms, medication burden, and quality of life in Parkinson’s disease (PD).

Background

MRgFUS subthalamotomy has emerged as a minimally invasive alternative for unilateral or bilateral lesioning in patients with PD. Multiple cohorts have reported improvement in motor symptoms, though variability across studies and follow‑up intervals remains. A pooled synthesis of outcomes can clarify the magnitude and durability of treatment effects.

Design/Methods

A systematic review of PubMed‑indexed clinical studies reporting pre‑ and post‑treatment outcomes of MRgFUS subthalamotomy was performed. Extracted measures included MDS‑UPDRS III (OFF), MDS-UPDRS II, PDQ‑39, and levodopa equivalent daily dose (LEDD). Adverse events (AEs) and their proportions were also collected. Random‑effects and fixed‑effect meta‑analyses were conducted across time points from 1 to 12 months.

Results

Across 5 studies (80 patients), MRgFUS subthalamotomy produced a significant improvement in MDS-UPDRS-III at all time points (MD −14.12; 95% CI −18.88 to −9.36; I2 97%) [Figure 1]. MDS-UPDRS II improved (MD −3.79; 95% CI −5.03 to −2.56; I2 0%), as did PDQ‑39 (MD −6.70; 95% CI −9.48 to −3.92; I2 0%) [Figure 2]. LEDD decreased by −148.89 mg (95% CI −210.32 to −87.45; I2 0%) [Figure 3]. Meta‑regression demonstrated that time from baseline did not significantly moderate outcomes. The most common AEs were gait ataxia (p=0.4; 95% CI 0.30–0.51), dyskinesia (p=0.35; 95% CI 0.25–0.45), dysarthria (p=0.31; 95% CI 0.22–0.42), and facial asymmetry (p=0.2; 95% CI 0.12–0.30).

Conclusions

MRgFUS subthalamotomy provides consistent, clinically meaningful reductions in motor severity, disability, and medication use up to 12 months post‑procedure. While generally well tolerated, transient gait and speech disturbances remain common. Further randomized and long‑term comparative studies are needed to refine patient selection and optimize safety.

Citation

Achuthaprasad A, Rissardo JP, Patino J,  Caprara AL, McGarry A, Walker I. Motor and Quality‑of‑Life Outcomes After MR‑Guided Focused Ultrasound Subthalamotomy for Parkinson’s Disease: A Meta‑analysis. Mov Disord 2026;41(Suppl_1):S1269-S1272.

Figure 1. Forest plot of pooled MD of motor outcomes.

Figure 2. Forest plot of pooled MD of PDQ-39 outcomes.

Figure 3. Forest plot of pooled MD of LEDD.

Clinical Impact of Nicotine in Parkinson’s Disease: Evidence from Randomized Controlled Studies

Title: Clinical Impact of Nicotine in Parkinson’s Disease: Evidence from Randomized Controlled Studies

Authors: Jamir Pitton Rissardo, Jorge Patino, Ana Leticia Fornari Caprara, Andrew McGarry, Ian Walker

Conference: 2026 International Congress of Parkinson's Disease, Seoul, Korea

Objective

To evaluate the effects of nicotine versus placebo in Parkinson’s disease (PD).

Background

Nicotine may influence dopaminergic and non‑dopaminergic pathways relevant to PD. While preclinical data suggest neuroprotective benefits, clinical trial results have been inconsistent.

Design/Methods

A meta‑analysis was conducted using PubMed‑indexed randomized controlled trials (RCTs) comparing nicotine (oral, transdermal patch, dietary) with placebo in PD. Outcomes included motor severity (MDS UPDRS‑III or equivalent), MDS UPDRS‑II, PDQ‑39/PDQ‑8, LEDD (levodopa equivalent daily dose), and adverse events. Subgroup analyses considered treatment duration (<12 weeks, 12–40 weeks, >40 weeks) and dose. Continuous outcomes were pooled using SMD and MD as appropriate. Random‑effects models with REML were used.

Results

Six studies, including 389 participants (active=203 experimental, control=186), were analyzed. Nicotine did not significantly improve motor outcomes (SMD −0.16; 95% CI −0.76 to 0.43; I² = 85%) [Figure 1] or functional disability (MD −0.65; 95% CI −1.77 to 0.47; I² = 0%). Quality‑of‑life measures showed a small but significant benefit favoring nicotine (SMD −0.26; 95% CI −0.44 to −0.07; I² = 0%) [Figure 2]. LEDD changes were nonsignificant (MD −114.40 mg; 95% CI −258.82 to 30.02; I² = 73%) [Figure 3]. Serious adverse events did not differ significantly (RR 1.97; 95% CI 0.97–4.01; I² = 0%), but total adverse events were more common with nicotine (RR 1.51; 95% CI 1.21–1.88). Nicotine increased risks of nausea (RR 3.40; 95% CI 1.81–6.39) and dizziness (RR 1.80; 95% CI 1.06–3.05), while headache, dry mouth, and palpitations showed nonsignificant associations.

Conclusions

Nicotine did not improve motor symptoms, disability, or LEDD, though it provided a small quality‑of‑life benefit. Adverse events, particularly nausea and dizziness, were more frequent. Current evidence does not support nicotine as a symptomatic therapy for PD.

Citation

Rissardo JP, Patino J,  Caprara AL, McGarry A, Walker I. Clinical Impact of Nicotine in Parkinson’s Disease: Evidence from Randomized Controlled Studies. Mov Disord 2026;41(Suppl_1):S1201-S1202.

Figure 1. Forest plot of pooled SMD of motor outcomes.

Figure 2. Forest plot of pooled SMD of quality of life outcomes.

Figure 3. Forest plot of pooled MD of LEDD.