Evidence map›Paper›PMID 41625999›Full record

ArticleBrain & spine2026

Mapping motor cortex "hand knob" metrics to symptom hemidominance in Parkinson's disease: from width comparison to machine learning.

Friedrich Erhart, Konstantin Hölzl, Agnes Langer, Christof Brücke, Josa M Frischer, Gregor Kasprian, Karl Rössler, Klaus Novak

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Article in Brain & spine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

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8 authors.

Friedrich ErhartDepartment of Neurosurgery, Medical University of Vienna, Vienna, Austria.
Konstantin HölzlDepartment of Neurosurgery, Medical University of Vienna, Vienna, Austria.
Agnes LangerDepartment of Neurology, Medical University of Vienna, Vienna, Austria.
Christof BrückeDepartment of Neurology, Medical University of Vienna, Vienna, Austria.
Josa M FrischerDepartment of Neurosurgery, Medical University of Vienna, Vienna, Austria.
Gregor KasprianDepartment of Biomedical Imaging and Image-guided Therapy, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Vienna, Austria.
Karl RösslerDepartment of Neurosurgery, Medical University of Vienna, Vienna, Austria.
Klaus NovakDepartment of Neurosurgery, Medical University of Vienna, Vienna, Austria.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Introduction: Parkinson's disease typically shows unilateral symptom dominance. Even though general neurodegeneration is well-documented, side-specific cortex affection has not been exhaustively studied. Research question: Specifically, we hypothesize that symptom hemidominance in Parkinson's disease might be associated with motor cortex "hand knob" size. To that end, we retrospectively analyzed 47 Parkinson's patients via structured morphometry, that had undergone standardized MRI for later deep brain stimulation surgery. Additionally, 25 control patients imaged with the same technical setup but without Parkinson's disease were investigated. Material and methods: Main dimensions of the "hand knob" (e.g. width and length) and compound measures (e.g. area and volume) were registered. Data analysis ranged from classical statistics for e.g. width comparison to advanced machine learning algorithms for integrated multivariable computation (e.g. t-SNE, Random Forest, Neural Networks and Naïve Bayes). Results: Left "hand knob" width appeared smaller in patients with right symptom hemidominance in exploratory univariable analyses (p = 0.026, uncorrected). In the control group this was not the case (p = 0.235). Complementary "hand knob" computations showed similar outcomes. All machine learning models concordantly suggested that integrated multivariable "hand knob" metrics can predict symptom side differences. Discussion and conclusion: Symptom hemidominance and "hand knob" parameters seem to possibly be connected. Specific cortical motor morphology dynamics of the "hand knob" might exist in hemidominant Parkinson's - for which we provide hitherto overlooked, indicative evidence based on a simple yet fundamental imaging inquiry complemented with advanced machine learning. The hypothesis-generating insights presented here shall inspire further research of cortical motor structures in Parkinson's.

Indexed as

“Hand knob”Machine learningMotor cortexParkinson'sSymptom hemidominance

Identifiers

PMID41625999
PMCPMC12858351

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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.