{
  "abstract": "Background\n\nThe Movement Disorder Society diagnostic criteria for progressive supranuclear palsy (PSP) list frequent square-wave jerks (SWJ) as a suggestive oculomotor feature. A standardised operational definition of SWJ is however presently lacking.Objective\n\nTo create a data-driven optimal SWJ definition and to assess its diagnostic utility in PSP.Methods\n\nWe prospectively recruited PSP n = 25, Parkinson's disease (PD) n = 32, Alzheimer's disease (AD) n = 35, and controls n = 88. SWJ were recorded with a visual fixation task using video-oculography. Multiple candidate definitions of SWJ were generated by systematically varying morphological features, producing 32 candidate definitions. A nested cross-validation was used to obtain unbiased diagnostic performance and optimised SWJ definition. Results were then externally tested in a fully independent sample of n = 25 PSP, n = 41 PD and n = 25 controls.Results\n\nThe optimal selected SWJ definition consisted of saccade amplitude 1°-8°, intra-SWJ intervals 20-600 ms, directional opposition within ±45°, and amplitude similarity ≤ 0.25. Only SWJ rate, and not morphological features, was distinctive for PSP. SWJ rate gave out-of-fold AUCs of 0.81 for PSP versus controls, 0.71 for PSP versus AD, 0.63 for PSP versus PD, and 0.76 for PSP versus all non-PSP groups. Post hoc analyses using this data-driven definition on the external validation cohort yielded relatively comparable results. SWJ rate > 24/min had high specificity, but low sensitivity, for PSP when compared with PD.Conclusions\n\nSWJ rate was significantly increased in PSP but with insufficient discriminant ability for use as a stand-alone diagnostic marker. This data-driven definition may serve as a reproducible operational definition for future research.",
  "abstract_shown": true,
  "affiliations": [
    "Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia, Queensland, Australia.",
    "Cognitive Health Program, Mater Research Institute, The University of Queensland, South Brisbane, Queensland, Australia.",
    "University of Medicine and Pharmacy, Hue University, Hue City, Vietnam.",
    "Neuroscience Research Centre, University Magna Graecia of Catanzaro, Catanzaro, Italy.",
    "Department of Medsical and Surgical Sciences, Institute of Neurology, University Magna Graecia of Catanzaro, Catanzaro, Italy.",
    "Neuro-Ophthalmology and Neuro-Otology Clinic, Department of Neurology, Royal Brisbane & Women's Hospital, Herston, Queensland, Australia.",
    "Department of Neurology, Royal Brisbane & Women's Hospital, Herston, Queensland, Australia.",
    "Faculty of Medicine, Frazer Institute, The University of Queensland, Herston, Queensland, Australia.",
    "Department of Neurology, Mater Adult Hospital, Mater Misericordiae Limited, South Brisbane, Queensland, Australia."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Duy Duan Nguyen",
      "orcid": "0000-0002-4773-1471"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Andrea Quattrone",
      "orcid": "0000-0003-2071-2083"
    },
    {
      "affs": [
        5
      ],
      "name": "Mark Paine"
    },
    {
      "affs": [
        0
      ],
      "name": "Amir Fazlollahi"
    },
    {
      "affs": [
        0
      ],
      "name": "Soohyun Lee"
    },
    {
      "affs": [
        0
      ],
      "name": "Baibin Ben Wang",
      "orcid": "0009-0000-7992-3403"
    },
    {
      "affs": [
        1
      ],
      "name": "Tanya Davidson"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Felicia Coleman"
    },
    {
      "affs": [
        6,
        7
      ],
      "name": "John D O'Sullivan",
      "orcid": "0000-0003-0422-8590"
    },
    {
      "affs": [
        0,
        1,
        8
      ],
      "name": "Peter J Nestor",
      "orcid": "0000-0002-5860-5921"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/39m4g92db20z3.bib",
  "cited_by": 0,
  "doi": "10.1111/ene.70790",
  "fulltext_url": "https://europepmc.org/articles/PMC13681254",
  "id": "39m4g92db20z3",
  "issns": [
    "1351-5101",
    "1468-1331"
  ],
  "landing_url": "https://europepmc.org/article/MED/42899365",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2728|Parkinson's Disease Mechanisms and Treatments"
    ]
  ],
  "openalex": "W7223054553",
  "pdf_url": "https://europepmc.org/articles/PMC13681254?pdf=render",
  "pmcid": "PMC13681254",
  "pmid": "42899365",
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/39m4g92db20z3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:37Z",
      "native_id": "MED:42899365",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42899365"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2728|Parkinson's Disease Mechanisms and Treatments",
      "subfield": "neurology"
    }
  ],
  "title": "A Data-Driven Operational Definition of Square-Wave Jerks and Its Diagnostic Utility in Progressive Supranuclear Palsy.",
  "title_text": "A Data-Driven Operational Definition of Square-Wave Jerks and Its Diagnostic Utility in Progressive Supranuclear Palsy.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:37Z",
  "url": "https://research.draconitic.com/paper/39m4g92db20z3",
  "venue": "European journal of neurology",
  "versions": []
}