Evidence map›Paper›PMID 32130515›Full record

ArticleDysphagia2020

Drooling in Parkinson's Disease: Prevalence and Progression from the Non-motor International Longitudinal Study.

Daniel J van Wamelen, Valentina Leta, Julia Johnson, Claudia Lazcano Ocampo, Aleksandra M Podlewska, Katarina Rukavina, Alexandra Rizos, Pablo Martinez-Martin, K Ray Chaudhuri

Open access · hybridAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Dysphagia, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 48 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
48citing papers in PubMed, 4 pooled it
4.6field-weighted citation impact, top 4% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

48 citing papers in PubMed, 4 syntheses or guidelines pooled it, 73 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Pooled it
  5. Trial
  6. Trial
  7. Patterns of spontaneous saliva swallowings during awake and sleep states in Parkinson's disease.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2026
    Article
  8. A rare case of oral myiasis in a non-tropical region: the role of systemic vulnerability.Revista do Instituto de Medicina Tropical de Sao Paulo · 2026
    Article
  9. Article
  10. Article
  11. Redefining Non-Motor Symptoms in Parkinson's Disease.Journal of personalized medicine · 2025
    Review
  12. Article
  13. Management of Gastrointestinal Symptoms in Parkinson's Disease.Journal of central nervous system disease · 2025
    Review
  14. Article
  15. Article
  16. Review
  17. Review
  18. Article
  19. Supplementation with Vitamin DInternational journal of molecular sciences · 2023
    Article
  20. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors at 4 institutions in 3 countries.

Daniel J van WamelenInstitute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neurosciences, King's College London, De Crespigny Park, London, SE5 8AF, UK. Daniel.van_wamelen@kcl.ac.uk.
Valentina LetaInstitute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neurosciences, King's College London, De Crespigny Park, London, SE5 8AF, UK.
Julia JohnsonParkinson Foundation Centre of Excellence At King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
Claudia Lazcano OcampoInstitute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neurosciences, King's College London, De Crespigny Park, London, SE5 8AF, UK.
Aleksandra M PodlewskaInstitute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neurosciences, King's College London, De Crespigny Park, London, SE5 8AF, UK.
Katarina RukavinaInstitute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neurosciences, King's College London, De Crespigny Park, London, SE5 8AF, UK.
Alexandra RizosInstitute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neurosciences, King's College London, De Crespigny Park, London, SE5 8AF, UK.
Pablo Martinez-MartinCenter for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED), Carlos III Institute of Health, 28031, Madrid, Spain.
K Ray ChaudhuriInstitute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neurosciences, King's College London, De Crespigny Park, London, SE5 8AF, UK.
King's College London · GBKing's College Hospital NHS Foundation Trust · GBBiomedical Research Networking Center on Neurodegenerative Diseases · ESComplejo Asistencial Sótero del Río · CL

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Sialorrhoea in Parkinson's disease (PD) is an often neglected yet key non-motor symptom with impact on patient quality of life. However, previous studies have shown a broad range of prevalence figures. To assess prevalence of drooling in PD and its relationship to quality of life, we performed a retrospective analysis of 728 consecutive PD patients who had a baseline and follow-up assessment as part of the Non-motor International Longitudinal Study (NILS), and for whom drooling presence and severity were available, assessed through the Non-Motor Symptoms Scale (NMSS). In addition, we analysed the prevalence of associated dysphagia through self-reported outcomes. Quality of life was assessed through the PDQ-8 scale. Baseline (disease duration 5.6 years) prevalence of drooling was 37.2% (score ≥ 1 NMSS question 19), and after 3.27 ± 1.74 years follow-up, this was 40.1% (p = 0.17). The prevalence of drooling increased with age (p < 0.001). The severity of drooling, however, did not change (p = 0.12). While in 456 patients without drooling at baseline, only 16% (n = 73) had dysphagia (question 20 of the NMSS), in those with drooling this was 34.3% (p < 0.001). At follow-up, the number of patients with dysphagia had increased, 20.4% with no drooling had dysphagia, and 43.6% with drooling had dysphagia. Both at baseline and follow-up, drooling severity was significantly positively associated with quality of life (PDQ-8; r = 0.199; p < 0.001). In moderately advanced PD patients, subjective drooling occurs in over one-third of patients and was significantly associated with decreased quality of life. Dysphagia occurred significantly more often in patients with drooling.

Indexed as

Parkinson DiseaseSialorrheaHumansLongitudinal StudiesPrevalenceQuality of LifeRetrospective StudiesSeverity of Illness IndexSurveys and QuestionnairesDeglutitionDeglutition disordersDroolingDysphagiaNon-motor symptoms scaleParkinson’s disease

Identifiers

PMID32130515
PMCPMC7669801
OpenAlexW3009225226

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.