Evidence map›Paper›PMID 41503736›Full record

ArticleEuropean journal of neurology2026

Objective Assessment of Facial Expressions in Parkinson's Disease During Deep Brain Stimulation ON and OFF States: A Pilot Study.

Sefa Ozturk, Duygu Dolen, Cafer Ikbal Gulsever, Huseyin Emre Dagdeviren, Onur Ozturk, Eren Andıc, Senem Kılıc Ozturk, Ahmet Muhammet Kocabıyık, Pulat Akın Sabancı

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Article in European journal of neurology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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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

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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

2 citing papers in PubMed.

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4 · The record

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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.

Sefa OzturkDepartment of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.ORCID 0000-0001-5583-0384
Duygu DolenDepartment of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Cafer Ikbal GulseverDepartment of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Huseyin Emre DagdevirenDepartment of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Onur OzturkDepartment of Neurosurgery, Taksim Acıbadem Hospital, Istanbul, Turkey.
Eren AndıcDepartment of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Senem Kılıc OzturkDepartment of Family Medicine, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Ahmet Muhammet KocabıyıkResearch Centre for Computer Science and Information Security Advanced Technologies, Kocaeli, Turkey.
Pulat Akın SabancıDepartment of Neurosurgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveParkinson's disease (PD) affects both motor and non-motor functions, including facial expressivity. While subthalamic nucleus deep brain stimulation (STN-DBS) is effective for motor symptoms, its impact on facial expression remains unclear. This study aimed to objectively assess the impact of DBS on facial movement timing and amplitude using objective facial landmark-based motion analysis.

methodsWe analyzed 10 PD patients with STN-DBS (≥ 3 years) and 10 age- and sex-matched controls. Standardized video recordings were obtained using a fixed camera setup. Facial movements were analyzed using objective facial landmark-based motion analysis implemented via a pre-trained facial landmark detection framework (Mediapipe), extracting 468 facial landmarks across approximately 1800 frames per recording. Key facial parameters, including smile completion time and region-specific ranges of motion (ROM), were quantified.

resultsDBS significantly increased oral commissure and frontal ROM (p < 0.05) while reducing smile completion time (p = 0.003). However, PD patients' smiles remained slower than those of controls (0.64 ± 0.21 s vs. 0.49 ± 0.09 s; p = 0.019), indicating incomplete normalization of facial expressivity. Medial eyebrow and palpebral movements showed no significant differences (p > 0.05).

conclusionSTN-DBS enhances the amplitude of some facial movements but does not fully restore temporal dynamics of facial expression. Persistent delays in smile execution suggest that aspects of facial motor control may remain impaired despite effective stimulation. Objective facial landmark-based motion analysis provides a sensitive tool for detecting subtle alterations in facial motor dynamics and may support future studies investigating complementary strategies to optimize motor expressivity in PD.

Indexed as

Deep Brain StimulationFacial ExpressionParkinson DiseaseAgedFemaleHumansMaleMiddle AgedMotion CapturePilot ProjectsSmilingSubthalamic Nucleusassessment of facial expressionsdeep brain stimulationfacial landmark‐based motion analysisobjective assessment of facial expressionsParkinson's disease

Identifiers

PMID41503736
PMCPMC12780872

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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.