Evidence map›Paper›PMID 32058266›Full record

ArticleParkinsonism & related disorders2020

Gastrointestinal symptoms are predictive of trajectories of cognitive functioning in de novo Parkinson's disease.

Jacob D Jones, Elizabeth Rahmani, Erik Garcia, Jonathan P Jacobs

Open access · greenAbstract readMulticenter Study
PubMed Full text at PMC Publisher
In one paragraph

Article in Parkinsonism & related disorders, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 42 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
42citing papers in PubMed, 3 pooled it
3.6field-weighted citation impact, top 5% 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

42 citing papers in PubMed, 3 syntheses or guidelines pooled it, 70 citations in OpenAlex.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Article
  5. Progress of Immunotherapies in Parkinson's Disease.CNS neuroscience & therapeutics · 2026
    Review
  6. Review
  7. Article
  8. Constipation Is Linked to Neuroinflammation in Early Parkinson's Disease.Movement disorders : official journal of the Movement Disorder Society · 2026
    Article
  9. Article
  10. Article
  11. Review
  12. Article
  13. Gut neuropeptide involvement in Parkinson's disease.American journal of physiology. Gastrointestinal and liver physiology · 2025
    Review
  14. Article
  15. Article
  16. Article
  17. Article
  18. Review
  19. Article
  20. Review
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

4 authors at 2 institutions in 1 country.

Jacob D JonesDepartment of Psychology, Center on Aging, California State University San Bernardino, San Bernardino, CA, USA. Electronic address: Jacob.jones@csusb.edu.
Elizabeth RahmaniDepartment of Psychology, Center on Aging, California State University San Bernardino, San Bernardino, CA, USA.
Erik GarciaDepartment of Psychology, Center on Aging, California State University San Bernardino, San Bernardino, CA, USA.
Jonathan P JacobsThe Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Division of Gastroenterology, Hepatology and Parenteral Nutrition, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
California State University, San Bernardino · USUniversity of California, Los Angeles · US

Funding

Modulation of the Intestinal Microbiome in Obesity by a High Protein DietIK2CX001717 · VA · VA GREATER LOS ANGELES HEALTHCARE SYSTEM · PI JACOBS, JONATHAN PATRICK · 2018 to 2023
–
CSRD VA IK2 CX001717
6 · The paper itself

Abstract

introductionNon-motor symptoms such as cognitive and gastrointestinal (GI) symptoms are common in Parkinson's disease (PD). In PD, GI-symptoms often present prior to motor symptoms. It is hypothesized that GI-symptoms reflect disruptions of the microbiome-gut-brain axis, which leads to altered immune functioning, chronic neuroinflammation, and subsequent neurodegeneration. Initial evidence links gut-dysbiosis to PD pathology and motor symptom severity. The present study examines the longitudinal relationship between severity of GI-symptoms and cognitive impairment in newly diagnosed PD patients.

methodsA secondary data analysis of the Parkinson's Progression Markers Initiative (PPMI) included 423 newly diagnosed PD patients who were followed for up to 5 years. Participants underwent neuropsychological tests of processing speed, attention, visuospatial functioning, verbal learning and verbal delayed recall. Participant were classified as cognitive intact, mild cognitive impairment or Parkinson's disease dementia. Frequency of GI-symptoms were assessed with the Scales for Outcomes in Parkinson's Disease Autonomic (SCOPA-AUT). Multi-level models (MLM) examined the longitudinal relationship between GI symptoms and cognitive impairment.

resultsAll cognitive outcomes were predicted by the main effect of GI symptoms, or the GI-symptom X Occasion interaction term. Specifically, more severe GI-symptoms were predictive of a less favorable trajectory of performance on tests of letter fluency, visuospatial, learning and memory. Cognitive performance was uniquely associated with GI-symptoms and unrelated to non-GI autonomic symptoms.

conclusionsThe presence of GI symptoms may serve as an early marker of cognitive impairment in PD. Future studies should examine specific mechanisms underlying the relationship between gut-dysbiosis and cognitive impairment.

Indexed as

Disease ProgressionAgedCognitive DysfunctionDementiaFemaleGastrointestinal DiseasesGastrointestinal MicrobiomeHumansLongitudinal StudiesMaleMiddle AgedParkinson DiseasePrognosisSeverity of Illness IndexDementiaGastrointestinal systemMicrobiomeMild cognitive impairmentParkinson's disease

Identifiers

PMID32058266
PMCPMC7179075
OpenAlexW3002063470

What OpenQuestion holds

Textmetadata
LicenceTDM
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.