Intraoral Acupuncture for Sialorrhea in Stroke Patients: a Study Protocol for a Randomized Controlled Trial.

Importance: Post-stroke sialorrhea (PSS) refers to excessive saliva flowing out the lip border after a stroke. PSS negatively affects patient self-image and social communication and may lead to depression. Limited evidence supports the link between excessive salivation and PSS. No large-scale, strictly controlled randomized controlled trials have shown the effectiveness of acupuncture in treating PSS patients. Objective: We aim to compare the effects of intraoral and sham acupuncture in PSS patients and explore relationships among salivation and drooling severity and frequency and swallowing function in stroke patients. Design: Clinical study protocol, SPIRIT compliant. Setting: Prospective, single-center, randomized, and sham-controlled trial. Population: We will recruit 106 PSS patients to receive 4-week intraoral or sham acupuncture. Additionally, 53 stroke patients without PSS will undergo a conventional 4-week treatment program to compare salivation between PSS and non-PSS patients. Exposures: Intraoral or sham acupuncture. Main Outcomes and Measures: The main evaluation index will be the 3-minute saliva weight (3MSW), comparing changes in 3MSW from baseline to weeks 4 and 8. Secondary assessment indices will include the "Drooling Severity and Frequency Scale" and "Functional Oral Intake Scale." Results: The results from this study will be published in peer-reviewed journals. Conclusion: Comparing effects of intraoral and sham acupuncture in PSS patients, this study may contribute important evidence for future PSS treatment and provide valuable insights into whether salivation issues in stroke patients are attributed to heightened salivary secretion or dysphagia.

Deep brain stimulation of the subthalamic nucleus increases the risk of sialorrhea in patients with advanced Parkinson's disease.

INTRODUCTION: Sialorrhea is a common neurological manifestation of Parkinson's disease (PD). No specifically designed prospective study has tested the effects of deep brain stimulation of the subthalamic nucleus (STN-DBS) on sialorrhea in patients with advanced PD. We focused on the effect of STN-DBS on the incidence of sialorrhea in patients with PD. METHODS: This multicenter, prospective, non-randomized concurrent clinical trial analyzed the incidence of sialorrhea during long-term follow-up in 170 patients with advanced PD (84 patients with STN-DBS and 86 patients with medication therapy). RESULTS: After STN-DBS, 58.1% of patients presented with sialorrhea (Drooling Rating Scale (DRS) > 5) compared with 39.3% of patients with medication therapy (P < 0.001). STN-DBS stimulation demonstrated a significant increase in DRS and Drooling Severity and Frequency Scale (DSFS) compared with the patients with medication therapy (P < 0.001). At follow-up, the onabotulinumtoxin-A (BTX-A) injection ratio was significantly higher in the STN-DBS group (29.8% vs. 11.9%, P = 0.0057) compared with the patients with medication therapy. CONCLUSIONS: STN-DBS increased the risk of sialorrhea in patients with advanced PD. TRIAL REGISTRATION: clinicaltrials. gov (NCT06090929).

Localization of the Submandibular Glands Using High-Frequency Ultrasound.

BACKGROUND: Injecting botulinum toxin (BTX) into the submandibular glands (SMGs) can treat drooling symptoms in neurological diseases and improve the aesthetics of SMG hypertrophy and ptotic SMGs. OBJECTIVES: This study aimed to define the size and position of the SMGs by high-frequency ultrasound, and to perform statistical analysis to improve the safety and accuracy of BTX injection therapy. METHODS: Neck ultrasonography with high-frequency ultrasound was performed on 214 volunteers. The length, height, and thickness of the SMGs, and the distance between the SMGs and the midline, the anterior border of the sternocleidomastoid, the mandible, and the surface were measured. RESULTS: The SMGs were almond-shaped with a mean [standard deviation] length of 33.7 [4.7] mm, a thickness of 13.3 [2.9] mm, and a height of 27.6 [6.0] mm. The length and height were significantly different between underage and youth groups. The size of the SMGs did not show any notable differences with increasing BMI; however, their depth, and the distance from the mandible, midline, and anterior border of the sternocleidomastoid increased. No significant differences were observed between the affected and healthy sides in patients with microtia, hemifacial microsomia, or cleft lip and palate. CONCLUSIONS: Ultrasound provides more comprehensive information regarding the size and position of the SMGs, which can serve as a reference in BTX therapy and in the diagnosis of SMG diseases involving size alterations.

Use of botox for sialorrhea and dysphagia in the neonatal population.

INTRODUCTION: Botox is frequently used for sialorrhea in patients with compromised airways and those with etiologies causing difficulty with secretion management (i.e. strokes, neurologic disorders, etc.). There are no published studies regarding the use of botulinum toxin (BoNT) in the neonate population. We aim to discuss our experience and safety of BoNT use in the neonate population in regards to alleviating secretion management and airway protection. METHODS: Retrospective review of neonates admitted to the neonatal intensive care unit (NICU) ≤12 months of age who received BoNT injection to submandibular (SMG) and parotid (PG) glands for sialorrhea/dysphagia. BoNT was administered under ultrasound (u/s) guidance by interventional radiology. RESULTS: 6 children were examined. 2 (33 %) were male. Avg NICU stay was 87.5 ± 33.1 days. 2 underwent surgical airway intervention prior to injection. Mean age at initial BoNT was 1.5 ± 0.7 months. Avg weight at injection was 4 ± 1.1 kg. Each PG and SMG were injected in 5/6 cases. Bilateral SMG were unidentified on u/s in 1 case and thus not injected. Dose range injected per gland was 5-15u. 100 % required tube feeds, 50 % with tubes distal to stomach (NJT/NDT). 83 % were completely NPO prior to injection and there was no noted clinical improvement in oral skills post injection. All had noted desats/apneas prior to injection and 83 % had reported decreased events post injection. 50 % had reported decrease O2 requirements and frequent suctioning 2wks after injection, however 2 (33 %) required surgical airway intervention after injection (trach, SGP/MDO). 4/6 (67 %) trialed medical therapy, anticholinergics being the most common. 50 % underwent 2nd injection (age = 6.5 ± 0.3 months) avg. 4.7 ± 0.7mo after 1st injection, and the same 3pts underwent 3rd injection (age = 12.5 ± 2.4 months) avg. 6.1 ± 2.5mo after 2nd injection. 1 pt. had a total 6 injections. There were no injection related complications. CONCLUSION: BoNT injection is a safe, non-invasive alterative for management of sialorrhea in neonates. Further extensive study needs to be performed to identify the optimal dose per gland in this population.

Glycopyrronium 320 µg/mL in children and adolescents with severe sialorrhoea and neurodisabilities: A randomized, double-blind, placebo-controlled trial.

AIM: To investigate the efficacy, safety, and impact on quality of life (QoL) of an oral formulation of 320 µg/mL glycopyrronium designed for children. METHOD: A double-blind, placebo-controlled SALIVA (Sialanar plus orAl rehabiLitation against placebo plus oral rehabilitation for chIldren and adolescents with seVere sialorrhoeA and neurodisabilities) trial was conducted. Children (3-17 years) with neurodisabilities and severe sialorrhoea (modified Teachers Drooling Scale ≥6) were randomized to 320 µg/mL glycopyrronium or placebo, in addition to non-pharmacological standard care. RESULTS: Of 87 participants, 44 were aged 10 years or under and 43 had cerebral palsy. The primary endpoint, change in total Drooling Impact Scale (DIS) score from baseline to day 84, was significantly greater (improved) with 320 µg/mL glycopyrronium versus placebo (median [quartile 1, quartile 3] -29.5 [-44.5, 0] vs -1 [-16, 5]; p < 0.001), an effect also observed at day 28 (median - 25 vs -2; p < 0.01). Significant reduction in bibs/clothes used per day was seen with glycopyrronium versus placebo at day 84 (median - 2 vs 0; p < 0.01). Glycopyrronium significantly improved DIS items 9 and 10 related to the extent that drooling affects the child's and family's life (p ≤ 0.03). Adverse events were reported by 77.3% and 69.8% of children with glycopyrronium and placebo respectively; the most common treatment-related adverse event was constipation (20.5% and 16.3%). INTERPRETATION: The formulation of 320 µg/mL glycopyrronium significantly improved drooling and reduced its impact on QoL, with good tolerability in children with neurodisabilities. WHAT THIS PAPER ADDS: The formulation of 320 µg/mL glycopyrronium significantly improved Drooling Impact Scale score versus placebo at day 84. The formulation reduced the impact of drooling on the child's and family's quality of life. There were no safety or tolerability concerns with this specific formulation.

Onabotulinum Toxin A (BoNT-A) for Drooling in Children: A Systematic Review and Meta-Analysis.

INTRODUCTION: Sialorrhea, also known as drooling, hypersalivation, or ptyalism, has a significant impact on the medical and psychosocial well-being of children. Onabotulinum toxin A (BoNT-A) is the most commonly used botulinum toxin worldwide for the treatment of sialorrhea in children. OBJECTIVES: To conduct a comprehensive systematic review and meta-analysis to assess the clinical efficacy and potential adverse effects of BoNT-A as a treatment for drooling in children. METHODS: Cochrane, Embase, and Medline databases were systematically searched (up to May 2023). Out of 535 identified publications, 20 were found eligible for inclusion. A systematic review and meta-analysis were performed to determine the efficacy of BoNT-A treatment in children in reducing the frequency and severity of drooling. RESULTS: Out of the 20 studies included, a meta-analysis was conducted on the complete dataset of eight studies involving 131 patients. BoNT-A was found to significantly decrease the severity of drooling in patients with sialorrhea (standardized mean difference [SMD], -2.07; 95% confidence interval [CI], -2.91 to -1.23; p < 0.0001) when compared with the conditions before injections using random-effects models. Six studies out of 20 reported dysphagia as an adverse effect after injection. Other side effects included thickness of saliva and pain at the site of injection. CONCLUSION: BoNT-A is a clinically effective therapy that improves drooling severity in children with sialorrhea. Although there were some adverse side effects reported, they were transient and not severe. Future studies are needed to further evaluate the best techniques and to identify the ideal dosages required to achieve the optimal outcomes. Laryngoscope, 134:3012-3017, 2024.

Comparing botulinum toxin and 4-duct ligation for Sialorrhea in children - A systematic review.

INTRODUCTION: Sialorrhea or drooling can result in physical and psychosocial complications, such as aspiration and social isolation. Treatment options include botulinum toxin into the salivary glands and 4-duct ligation (i.e., simultaneous ligation of the bilateral parotid and submandibular ducts). This systematic review aimed to compare the efficacy and complication rates of botulinum toxin and 4-duct ligation for the treatment of drooling in children. METHODS: Following PRISMA guidelines, PubMed, Embase, Web of Science, and Cochrane Library were searched from inception through June 17, 2021 for studies examining the efficacy of botulinum toxin or 4-duct ligation for drooling in children. Data were summarized by pooled counts, percentages, and means. Complication rates were compared by a chi-squared test. RESULTS: A total of 22 studies (n = 606) examining botulinum toxin and 5 studies (n = 124) examining 4-duct ligation were included. From 12 botulinum toxin studies (n = 211), mean drooling frequency and severity scores was 7.5 at baseline. Mean difference from baseline was -2.6 (n = 92) at 4 weeks follow-up, -2.1 at 8 weeks (n = 41), -2.1 at 12 weeks (n = 56), and - 2.1 at 16 weeks (n = 58). From 4 4-duct ligation studies (n = 103), mean baseline drooling frequency and severity score was 8.4. Mean difference was -3.7 at mean follow-up of 35.6 months (n = 103). Eighteen botulinum studies (n = 343) recorded 53 (15.5 %) complications, including thickened saliva (n = 9), dysphagia (n = 4), and cheek abscesses (n = 4). Four 4-duct ligation studies (n = 108) recorded 25 (23.1 %) complications, including parotid gland swelling (n = 4), aspiration pneumonia (n = 3), and oxygen desaturation (n = 3). There was no statistically significant difference in complication rates between botulinum toxin and four-duct ligation (p = 0.065). CONCLUSION: Botulinum toxin injection and 4-duct ligation are both effective in improving sialorrhea in children and have comparable complication rates.

Comparative Efficacy and Side Effect Profiles of Interventions for Pediatric Saliva Control: A Cohort Study.

OBJECTIVE: To compare efficacy and side effect profile data on conservative, behavioral, pharmacological, and surgical treatments used for pediatric saliva control. STUDY DESIGN: A cohort study of children (n = 483) referred to a specialty Saliva Control service between May 2014 and November 2019 was performed, using quantitative data from pretreatment and post-treatment questionnaires (the Drooling Impact Scale [DIS], Drooling Rating Scale [DRS]) and recording of side effects. Overall, 483 children were included; treatment choices were based on published international guidelines. RESULTS: The greatest improvement was seen after intraglandular botulinum toxin A (BTX-A) injections (n = 207; 551 courses; mean DIS change, 34.7; 95% CI = 29.2-35.7) or duct transpositional surgery (n = 31; mean change in DIS, 29.0; 95% CI, 22.3-35.7). Oral anticholinergics were associated with good outcomes, with no significant statistical difference between glycopyrronium bromide (n = 150; mean DIS change, 21.5; 95% CI, 19.1-24.0) or trihexyphenidyl (n = 87; mean DIS change, 22.4; 95% CI, 18.9-25.8). Inhaled ipratropium bromide was not as efficacious (n = 80; mean DIS change, 11.1; 95% CI, 8.9-13.3). Oromotor programs were used in a selected group with reliable outcomes (n = 9; mean DIS change, 13.0). Side effects were consistent with previous studies. Overall, in cases of milder severity, enterally administered therapies provided a good first-line option. With more severe problems, BTX-A injections or saliva duct transpositional surgery were more effective and well tolerated. CONCLUSIONS: We describe a large, single-center pediatric saliva control cohort, providing direct comparison of the efficacy and side effect profiles for all available interventions and inform clinical practice for specialists when considering different options. BTX-A injections or saliva duct transpositional surgery seem to be more effective for saliva control that is more severe.

Comparing the evidence for botulinum neurotoxin injections in paediatric anterior drooling: a scoping review.

Paediatric anterior drooling has a major impact on the daily lives of children and caregivers. Intraglandular botulinum neurotoxin type-A (BoNT-A) injections are considered an effective treatment to diminish drooling. However, there is no international consensus on which major salivary glands should be injected to obtain optimal treatment effect while minimizing the risk of side effects. This scoping review aimed to explore the evidence for submandibular BoNT-A injections and concurrent submandibular and parotid (i.e. four-gland) injections, respectively, and assess whether outcomes could be compared across studies to improve decision making regarding the optimal initial BoNT-A treatment approach for paediatric anterior drooling. PubMed, Embase, and Web of Science were searched to identify relevant studies (until October 1, 2023) on submandibular or four-gland BoNT-A injections for the treatment of anterior drooling in children with neurodevelopmental disabilities. Similarities and differences in treatment, patient, outcome, and follow-up characteristics were assessed. Twenty-eight papers were identified; 7 reporting on submandibular injections and 21 on four-gland injections. No major differences in treatment procedures or timing of follow-up were found. However, patient characteristics were poorly reported, there was great variety in outcome measurement, and the assessment of side effects was not clearly described.   Conclusion: This review highlights heterogeneity in outcome measures and patient population descriptors among studies on paediatric BoNT-A injections, limiting the ability to compare treatment effectiveness between submandibular and four-gland injections. These findings emphasize the need for more extensive and uniform reporting of patient characteristics and the implementation of a core outcome measurement set to allow for comparison of results between studies and facilitate the optimization of clinical practice guidelines. What is Known: • There is no international consensus on which salivary glands to initially inject with BoNT-A to treat paediatric drooling. What is New: • Concluding on the optimal initial BoNT-A treatment based on literature is currently infeasible. There is considerable heterogeneity in outcome measures used to quantify anterior drooling.and clinical characteristics of children treated with intraglandular BoNT-A are generally insufficiently reported. • Consensus-based sets of outcome measures and patient characteristics should be developed and implemented.

Predicting non-response to intraglandular botulinum neurotoxin A injections for drooling in children with neurodevelopmental disabilities.

AIM: To develop robust multivariable prediction models for non-response to (1) submandibular botulinum neurotoxin A (BoNT-A) injections and (2) concurrent submandibular and parotid (four-gland) injections, to guide treatment decisions for drooling in children with neurodevelopmental disabilities, including cerebral palsy. METHOD: This was a retrospective cohort study including 262 children (155 males/107 females, median age 7 years 11 months [IQR 5 years 1 month], range 4 years 0 months - 17 years 11 months) receiving submandibular injections and 74 children (52 males/22 females, median age 7 years 7 months [IQR 4 years 3 months], range 4 years 9 months - 18 years 8 months) receiving four-gland injections. Multivariable logistic regression analyses were used to estimate associations between candidate predictors and non-response 8 weeks after injection. RESULTS: Ninety-six children (37%) were non-responders to submandibular injections, for which developmental age was the strongest predictor (adjusted odds ratio [aOR] 2.13; 95% confidence interval [CI] 1.02-4.45 for developmental age <4 years or 4-6 years with IQ <70). Other characteristics that showed a trend towards an increased risk of non-response were diagnosis, sex, and head position. Thirty-four children (46%) were non-responders to four-gland injections, for which tongue protrusion (aOR 3.10; 95% CI 1.14-8.43) seemed most predictive, whereas multiple preceding submandibular injections (aOR 0.34; 95% CI 0.10-1.16) showed a trend towards being protective. Predictors were, however, unstable across different definitions of non-response and both models (i.e. submandibular and four-gland) had insufficient discriminative ability. INTERPRETATION: Potential predictors of non-response to BoNT-A injections were identified. Nevertheless, the developed prediction models seemed inadequate for guidance of treatment decisions. WHAT THIS PAPER ADDS: Developmental age seemed most predictive of non-response to submandibular botulinum neurotoxin A injections. Non-response to concurrent submandibular and parotid injections was best predicted by tongue protrusion and number of previous injections. Multivariable prediction models including these clinical characteristics were unable to discriminate well. Predictors differed when non-response was defined using alternative outcome measures.

The effectiveness and safety of botulinum toxin injections for the treatment of sialorrhea with Parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: Botulinum toxin (BoNT) injection is an important adjunctive method to treat sialorrhea. The purpose of this systematic review was to analyze the effect and safety of BoNT injections in the intervention of sialorrhea with Parkinson's disease (PD). METHODS: We searched PubMed, Web Of Science (WOS), Scopus, Cochrane CENTRAL, and Embase from inception until April 2022. Randomized controlled trials or randomized crossover trials comparing BoNT with placebo in sialorrhea with PD were eligible. PRISMA guidelines were used to carry out the meta-analysis. The Drooling Severity Frequency Scale (DSFS) score and the number of adverse events (AEs) were the primary and secondary outcomes, respectively. Standardized mean differences (SMDs) and risk differences (RDs) are used to express continuous and categorical outcomes, respectively. Heterogeneity among these studies was evaluated using I2 tests. We used the GRADE tool to assess the certainty of evidence (COE). RESULTS: Eight articles involving 259 patients compared BoNT injections with a placebo for PD with sialorrhea. This meta-analysis showed a significant reduction in DSFS scores between BoNT injections and placebo (SMD=-0.98; 95% CI, -1.27 to 0.70, p<0.001; COE: high). This meta-analysis showed a significant difference in AEs between BoNT injections and placebo (RD=0.15; 95% CI, 0.05 to 0.24, p=0.002; COE: low). CONCLUSIONS: The pooled results suggest that BoNT injections have some effect on DSFS scores with sialorrhea caused by PD. There are also mild adverse events, which generally recover within a week or so. The results indicate that BoNT injection is one of the treatments for sialorrhea caused by PD, but we need to pay attention to adverse events. In addition, the follow-up time was extended to observe oral hygiene, ulceration or dental caries, and digestive function. TRIAL REGISTRATION: Our review protocol was registered on PROSPERO (42021288334).

Botulinum toxin in the treatment of sialorrhea in severe neurological patients with tracheotomy.

OBJECTIVE: To observe the clinical effect of botulinum toxin type A (BTA) injection into the salivary glands of the severe neurological patients with tracheotomy METHODS: Seven patients with severe neurological disorders after tracheotomy and obvious drooling symptoms were enrolled. BTA was injected into bilateral parotid glands and submandibular glands under the guidance of ultrasound. Unstimulated salivary flow rate (uSFR) and Drooling Severity and Frequency Scale (DSFS) were used to evaluate drooling before injection, 1 week, and 4 weeks after injection. We compared the extubation time, time of changing from balloon cannula to metal cannula, hospitalization time and incidence of recurrent pulmonary infection between these patients and other patients accepted conventional curation. RESULTS: (1) The drooling severity scale (DSFS-S), the drooling frequency scale (DSFS-F), the drooling frequency and severity scale total score (DSFS-T) were significantly lower at 4 weeks after BTA injection compared to prior-treatment (p < .001). (2) uSFR of 1 week and 4 weeks were both statistically decreased than the untreated condition (p < .001). (3) Compared with the conventional group, the time of changing from balloon cannula to metal cannula was shortened obviously (p < .05) and incidence of recurrent pulmonary infection was clearly decreased (p < .05) after BTA treatment CONCLUSION: Ultrasound-guided BTA injection into salivary glands can effectively reduce saliva secretion. We also found that the time of changing cannula was shortened obviously and the incidence of recurrent pneumonia infection was reduced. BTA injection of salivary glands to cure drooling could advance to the clinical therapy in severe neurological patients after tracheotomy.

Comparison of factors associated with drooling between intractable neuromuscular disease and cerebral palsy.

Drooling represents a common and noteworthy symptom in patients with intractable neuromuscular disease (IND) and cerebral palsy (CP) and can lead to poor quality of life (QOL) and higher incidence of death due to aspiration of saliva. Identifying the factors affecting drooling is crucial to improving QOL and improving the poor prognosis of patients with IND and CP. This study sought to assess the prevalence of drooling and to elucidate the associated factors, drugs, and differences between patients with IND and CP. We included hospitalized patients with IND and CP. Among the 269 patients, 69 of 162 patients with IND (42.6%) and 75 of 107 patients with CP (70.1%) exhibited drooling. Drooling in IND was significantly higher in patients with tube feeding and those who had a previous stroke than in patients with potential oral intake and those having no history of stroke. In individuals with CP, drooling was significantly negatively associated with age. Taltirelin in patients with IND had a significant positive association with drooling, and antipsychotics and centrally acting muscle relaxants in those with CP had a significant negative association with drooling. Our results suggest that the factors associated with frequent drooling differ between IND and CP cases, and patients who should be screened for drooling are those with decreased swallowing function, those with IND who have had a previous stroke, and young patients with CP. Moreover, clinicians should consider the impact of drugs on drooling in IND and CP cases.

Randomised, double-blind, placebo-controlled trial of glycopyrronium in children and adolescents with severe sialorrhoea and neurodisabilities: protocol of the SALIVA trial.

INTRODUCTION: Severe sialorrhoea is a common, distressing problem in children/adolescents with neurodisabilities, which has adverse health and social consequences. The SALIVA trial is designed to evaluate the efficacy and safety of a paediatric-specific oral solution of glycopyrronium along with its impact on quality-of-life (QoL), which has been lacking from previous trials of sialorrhoea treatments. METHODS AND ANALYSIS: A double-blind, placebo-controlled, randomised phase IV trial is ongoing in several centres across France. Eighty children aged 3-17 years with severe sialorrhoea (≥6 on the modified Teachers Drooling Scale) related to chronic neurological disorders in whom non-pharmacological standard of care has already been implemented or has failed, will be recruited. Patients will be randomised 1:1 to receive a 2 mg/5 mL solution of glycopyrronium bromide (Sialanar 320 µg/mL glycopyrronium) or placebo three times daily during a 3-month blinded period. After Day 84, participants will be invited into a 6-month, open-label study extension period, where they will all receive glycopyrronium. The primary endpoint of the double-blind period will be the change from baseline to Day 84 in the Drooling Impact Scale (DIS), a validated measure to assess sialorrhoea. A series of secondary efficacy endpoints involving change in total DIS, specific DIS items and response (DIS improvement ≥13.6 points) will be analysed in a prespecified hierarchy. QoL data will be collected from parents, caregivers and patients where possible using specific DIS questions and DISABKIDS questionnaires. Safety endpoints, including adverse events, will be assessed throughout the trial periods. ETHICS AND DISSEMINATION: In total, 87 children have been recruited and recruitment is now complete. Final results are expected by the end of 2023. Findings will be presented at conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: EudraCT 2020-005534-15.

Drooling disrupts the brain functional connectivity network in Parkinson's disease.

AIMS: This study aimed to investigate the causal interaction between significant sensorimotor network (SMN) regions and other brain regions in Parkinson's disease patients with drooling (droolers). METHODS: Twenty-one droolers, 22 PD patients without drooling (non-droolers), and 22 matched healthy controls underwent 3T-MRI resting-state scans. We performed independent component analysis and Granger causality analysis to determine whether significant SMN regions help predict other brain areas. Pearson's correlation was computed between imaging characteristics and clinical characteristics. ROC curves were plotted to assess the diagnostic performance of effective connectivity (EC). RESULTS: Compared with non-droolers and healthy controls, droolers showed abnormal EC of the right caudate nucleus (CAU.R) and right postcentral gyrus to extensive brain regions. In droolers, increased EC from the CAU.R to the right middle temporal gyrus was positively correlated with MDS-UPDRS, MDS-UPDRS II, NMSS, and HAMD scores; increased EC from the right inferior parietal lobe to CAU.R was positively correlated with MDS-UPDRS score. ROC curve analysis showed that these abnormal ECs are of great significance in diagnosing drooling in PD. CONCLUSION: This study identified that PD patients with drooling have abnormal EC in the cortico-limbic-striatal-cerebellar and cortio-cortical networks, which could be potential biomarkers for drooling in PD.