Symptoms of Parkinson Disease a Decade Before Diagnosis

Summary and Comment |
December 18, 2014

Symptoms of Parkinson Disease a Decade Before Diagnosis

  1. Michael S. Okun, MD

Numerous symptoms identified in the primary care setting were more common in patients later diagnosed with PD.

  1. Michael S. Okun, MD

Parkinson disease (PD) is in general a slowly progressive disease, and some evidence suggests that symptoms can occur years before diagnosis. To examine the prevalence of prediagnostic symptoms, investigators drew data from The Health Improvement Network UK primary care database, which represents approximately 6% of the entire U.K. population. The authors compared symptoms within 2, 5, and 10 years before PD diagnosis in 8166 adult patients with symptoms within the same time periods after randomly assigned dates for 46,755 controls matched to cases for age, sex, and database registration date.

Within 2 years before diagnosis, tremor was the most common symptom in PD patients (41%) versus controls (<1%); most other studied symptoms were more common in the PD group as well, except neck pain or stiffness. Within 2 to 5 years before diagnosis, the PD group had more tremor, balance problems, constipation, hypotension, erectile dysfunction, urinary dysfunction, dizziness, fatigue, depression, and anxiety. Within 5 to 10 years, tremor and constipation were more common in patients than controls.


Researchers are keenly interested in identifying clinical symptoms, as well as other biomarkers (e.g., imaging, blood), that may predict a later diagnosis of Parkinson disease. Several candidate symptoms have been suggested, and the current study identified motor and nonmotor features that could be present up to a decade before diagnosis. Early identification of PD may have implications for clinical trials and for the early identification of individuals who may benefit from disease-modifying therapies.

The dataset used in this study was large, and the findings are convincing. However, whether all of the patients in this cohort had PD is unclear; many may have had parkinsonism but were misclassified based on the expertise available. Also, there may have been underreporting or underrecognition of symptoms in the primary care setting. Despite these limitations, the findings support mounting evidence of identifiable symptoms that may occur many years before a formal diagnosis of Parkinson disease.

Editor Disclosures at Time of Publication

  • Disclosures for Michael S. Okun, MD at time of publication Grant / Research support NIH; National Parkinson Foundation; Michael J. Fox Foundation; Tourette Syndrome Association; Bachmann-Strauss; Dystonia Medical Research Foundation Editorial boards National Parkinson Foundation; Parkinsonism and Related Disorders; Tremor and Hyperkinetic Disorders Leadership positions in professional societies National Parkinson Foundation (National Medical Director); Tourette Syndrome Association (Co-Chair Medical Advisory Board); The International Parkinson and Movement Disorder Society (International Executive Committee)


Reader Comments (2)

OSVALDO BUSTOS Physician, Family Medicine/General Practice, University

In addition to all the symptoms described above, hasn't the loss of olfaction been identified as an early symptom of PD as well?

William Tuey Other, Unspecified

Interested in any follow up studies by others

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