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Parkinson disease

Last reviewed: 28 Oct 2023
Last updated: 22 Aug 2023



History and exam

Key diagnostic factors

  • bradykinesia
  • resting tremor
  • rigidity
  • postural instability
More key diagnostic factors

Other diagnostic factors

  • masked facies
  • hypophonia
  • hypokinetic dysarthria
  • micrographia
  • stooped posture
  • shuffling gait
  • conjugate gaze disorders
  • fatigue
  • constipation
  • depression
  • anxiety
  • dementia
  • exposure to antipsychotics or antiemetics
  • features of atypical parkinsonism
  • hyposmia/anosmia
  • sleep disorders
Other diagnostic factors

Risk factors

  • increasing age
  • history of familial PD in younger-onset disease
  • mutation in gene encoding glucocerebrosidase
  • 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) exposure
  • chronic exposure to metals
  • male sex
  • additional genetic risk factors
  • head trauma
  • geographic influence
  • toxin exposure
  • occupation
More risk factors

Diagnostic investigations

1st investigations to order

  • dopaminergic agent trial
More 1st investigations to order

Investigations to consider

  • MRI brain
  • functional neuroimaging (dopamine transporter imaging such as FP-CIT or beta-CIT SPECT, or fluorodopa PET)
  • olfactory testing
  • genetic testing
  • neuropsychometric testing
  • serum ceruloplasmin
  • 24-hour urine copper
  • cardiac sympathetic innervation using iodine-123 meta-iodobenzylguanidine (MIBG)
  • brain pathology (postmortem)
More investigations to consider

Emerging tests

  • skin biopsy

Treatment algorithm


mild parkinsonism

moderate parkinsonism

advanced parkinsonism



Delaram Safarpour, MD, MSCE

Assistant Professor of Neurology

Department of Neurology

School of Medicine

Oregon Health & Science University




DS has received honoraria for participation in advisory boards for Boston Scientific (the manufacturer of Deep Brain Stimulation device) and Abbvie (the manufacturer of Duopa). She has received consultation fees from Abbott (the manufacturer of Deep Brain Stimulation device). DS has received an institutional grant and has received an honorarium for lectures from Parkinson Study Group.

Marian L. Dale, MD, MCR

Assistant Professor of Neurology

Department of Neurology

Oregon Health & Science University

Staff Neurologist

Portland VA Medical Center




MLD has received consulting honoraria from Synergic Medical Technologies and UCB, and has received grant funding from the NIH and the Collins Medical Trust.

Lauren S. Talman, MD

Assistant Professor of Neurology

Department of Neurology

School of Medicine

Oregon Health & Science University




LST declares that she has no competing interests.


Dr Delaram Safarpour, Dr Marian L. Dale, and Dr Lauren S. Talman would like to gratefully acknowledge Dr Avram Fraint, Dr Danny Bega, Dr Meredith Spindler, Dr Jayne R. Wilkinson, and Dr Andrew D. Siderowf, the previous contributors to this topic.


DB served on the speaker's bureau for Teva Pharmaceuticals, and ACADIA Pharmaceutical, Inc; he has received consultancy fees from US WorldMeds and grant support from the Parkinson Foundation; he was on the board of directors for Rock Steady Boxing Windy City. AF, MS, JRW, and ADS declare that they have no competing interests.

Peer reviewers

Graham A. Glass, MD

Assistant Clinical Professor

Department of Neurology

UCSF Medical Center

Parkinson's Disease Research

Education and Clinical Center

San Francisco



GAG declares that he has no competing interests.

Daniel Kremens, MD, JD

Assistant Professor of Neurology

Jefferson Medical College

Thomas Jefferson University




DK declares that he has no competing interests.

Donald Grosset, BSc (Honours), MB, ChB, MD, FRCP

Consultant Neurologist / Honorary Senior Lecturer

Institute of Neurological Sciences

Southern General Hospital / University of Glasgow




DG is an author of a reference cited in this topic.

Patricia Dowsey Limousin, MD, PhD

Reader in Clinical Neurology

Honorary Consultant

Institute of Neurology

National Hospital for Neurology and Neurosurgery




PDL declares that she has no competing interests.

Nikolaus McFarland, MD, PhD

Assistant Professor

Department of Neurology

University of Florida College of Medicine




NM declares that he has no competing interests.

  • Differentials

    • Essential tremor
    • Progressive supranuclear palsy (PSP)
    • Multiple system atrophy (MSA; MSA-A, formerly Shy-Drager syndrome; MSA-P, striatonigral degeneration; MSA-C, olivopontocerebellar atrophy)
    More Differentials
  • Guidelines

    • ACR–ACNM–SNMMI practice parameter for the performance of dopamine transporter (DaT) single photon emission computed tomography (SPECT) imaging for movement disorders
    • European Academy of Neurology/Movement Disorder Society - European Section guideline on the treatment of Parkinson's disease: I. Invasive therapies
    More Guidelines
  • Patient leaflets

    Parkinson disease: what is it?

    Parkinson's disease: what treatments work?

    More Patient leaflets
  • Videos

    Parkinson disease neurological assessment

    More videos
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