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Parkinson's disease

  • Overview
  • Theory
  • Diagnosis
  • Management
  • Follow up
  • Resources
Last reviewed: 10 Aug 2025
Last updated: 23 May 2025

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • bradykinesia
  • resting tremor
  • rigidity
  • postural instability
Full details

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
Full details

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
Full details

Diagnostic investigations

1st investigations to order

  • dopaminergic agent trial
Full details

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)
Full details

Emerging tests

  • skin biopsy

Treatment algorithm

ONGOING

mild parkinsonism

moderate parkinsonism

advanced parkinsonism

Contributors

Authors

Delaram Safarpour, MD, MSCE

Assistant Professor of Neurology

Department of Neurology

School of Medicine

Oregon Health & Science University

Portland

OR

Disclosures

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

Portland

OR

Disclosures

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

Portland

OR

Disclosures

LST declares that she has no competing interests.

Acknowledgements

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.

Disclosures

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

CA

Disclosures

GAG declares that he has no competing interests.

Daniel Kremens, MD, JD

Assistant Professor of Neurology

Jefferson Medical College

Thomas Jefferson University

Philadelphia

PA

Disclosures

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

Glasgow

UK

Disclosures

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

London

UK

Disclosures

PDL declares that she has no competing interests.

Nikolaus McFarland, MD, PhD

Assistant Professor

Department of Neurology

University of Florida College of Medicine

Gainesville

FL

Disclosures

NM declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Postuma RB, Berg D, Stern M, et al. MDS clinical diagnostic criteria for Parkinson's disease. Mov Disord. 2015 Oct;30(12):1591-601. Abstract

Internation Parkinson and Movement Disorder Society. MDS position paper: diagnosis of Parkinson's disease. Mar 2023 [internet publication].Full text

Pringsheim T, Day GS, Smith DB, et al; Guideline Subcommittee of the AAN. Dopaminergic therapy for motor symptoms in early Parkinson disease practice guideline summary: a report of the AAN Guideline Subcommittee. Neurology. 2021 Nov 16;97(20):942-57.Full text  Abstract

Seppi K, Ray Chaudhuri K, Coelho M, et al. Update on treatments for nonmotor symptoms of Parkinson's disease - an evidence-based medicine review. Mov Disord. 2019 Feb;34(2):180-98.Full text  Abstract

Fox SH, Katzenschlager R, Lim SY, et al. International Parkinson and Movement Disorder Society evidence-based medicine review: update on treatments for the motor symptoms of Parkinson's disease. Mov Disord. 2018 Aug;33(8):1248-66.Full text  Abstract

Rughani A, Schwalb JM, Sidiropoulos C, et al. Congress of Neurological Surgeons systematic review and evidence-based guideline on subthalamic nucleus and globus pallidus internus deep brain stimulation for the treatment of patients with Parkinson's disease: executive summary. Neurosurgery. 2018 Jun 1;82(6):753-6.Full text  Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

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