SynthesisPloS one2016
Changes in Olfactory Bulb Volume in Parkinson's Disease: A Systematic Review and Meta-Analysis.
Synthesis in PloS one, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 40 papers, 1 of them a synthesis that pooled 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.
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.
Who cites it
40 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Associations between olfactory dysfunction and structural MRI findings in Parkinson's disease: a systematic review.Brain imaging and behavior · 2026Pooled it
- Gamma and beta oscillatory signatures of the human olfactory bulb encode odor valence and sampling.iScience · 2026Article
- Olfactory Dysfunction in a Novel Model of Prodromal Parkinson's Disease in Adult Zebrafish.International journal of molecular sciences · 2025Article
- RNA sequencing of olfactory bulb in Parkinson's disease reveals gene alterations associated with olfactory dysfunction.Neurobiology of disease · 2024Article
- Nicotine restores olfactory function by activation of prok2R/Akt/FoxO3a axis in Parkinson's disease.Journal of translational medicine · 2024Article
- Clinical significance of MRI-measured olfactory bulb height as an imaging biomarker of idiopathic Parkinson's disease.PloS one · 2024Article
- Specific structural changes in Parkinson's disease-related olfactory dysfunction compared to others forms of olfactory dysfunction.Frontiers in neural circuits · 2024Article
- A review of the gastrointestinal, olfactory, and skin abnormalities in patients with Parkinson's disease.Neurosciences (Riyadh, Saudi Arabia) · 2024Review
- Unraveling the Link between Olfactory Deficits and Neuropsychiatric Disorders.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2023Review
- Article
- Olfactory Dysfunction in Parkinson's Disease, Its Functional and Neuroanatomical Correlates.NeuroSci · 2023Review
- Olfactory Bulb Volume, Olfactory Sulcus Depth in Parkinson's Disease, Atypical Parkinsonism.Movement disorders clinical practice · 2023Article
- Quantitative analysis of the olfactory system in pediatric epilepsy: a magnetic resonance imaging studyDiagnostic and interventional radiology (Ankara, Turkey) · 2023Article
- Subjective Impairments in Olfaction and Cognition Predict Dissociated Behavioral Outcomes.The journals of gerontology. Series B, Psychological sciences and social sciences · 2023Article
- Neurons, Nose, and Neurodegenerative Diseases: Olfactory Function and Cognitive Impairment.International journal of molecular sciences · 2023Review
- Three-Dimensional Constructive Interference in Steady State (3D CISS) Imaging and Clinical Applications in Brain Pathology.Biomedicines · 2022Review
- Peripheral and Central Smell Regions in Migraine Patients using Maraş Powder (Smokeless Tobacco): A Magnetic Resonance Imaging Evaluation.Journal of neurological surgery. Part B, Skull base · 2022Article
- A comparative neuroimaging perspective of olfaction and higher-order olfactory processing: on health and disease.Seminars in cell & developmental biology · 2022Review
- α-synucleinopathy exerts sex-dimorphic effects on the multipurpose DNA repair/redox protein APE1 in mice and humans.Progress in neurobiology · 2022Article
- Transcriptome profiling of five brain regions in a 6-hydroxydopamine rat model of Parkinson's disease.CNS neuroscience & therapeutics · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveThe changes in olfactory bulb (OB) volume in Parkinson's disease (PD) patients have not yet been comprehensively evaluated. The purpose of this meta-analysis was to explore whether the OB volume was significantly different between PD patients and healthy controls.
methodsPubMed and Embase were searched up to March 6, 2015 with no language restrictions. Two independent reviewers screened eligible studies and extracted data on study characteristics and OB volume. Additionally, a systematic review and meta-analysis using a random-effects model were conducted. Publication bias was determined by using funnel plots and Begg's and Egger's tests. Subgroup analyses were performed to assess possible sources of heterogeneity.
resultsSix original case-control studies of 216 PD patients and 175 healthy controls were analyzed. The pooled weighted mean difference (WMD) in the OB volume between the PD patients and the healthy participants was -8.071 for the right OB and -10.124 for the left OB; these values indicated a significant difference among PD patients compared with healthy controls. In addition, a significant difference in the lateralized OB volume was observed in PD patients, with a pooled WMD of 1.618; these results indicated a larger right OB volume than left OB volume in PD patients. In contrast, no difference in the lateralized OB volume was found in healthy controls. No statistical evidence of publication bias among studies was found based on Egger's or Begg's tests. Sensitivity analyses revealed that the results were consistent and robust.
conclusionsOverall, both the left and the right OB volume were significantly smaller in PD patients than in healthy controls. However, significant heterogeneity and an insufficient number of studies underscore the need for further observational research.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
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.