Pain May Be Early Detector of Parkinson’s, Study Suggests

Patients likely to have prodromal, or early, Parkinson’s disease tend to have a higher prevalence of pain, according to a new study.

The findings indicate that pain may be a relevant disease marker before the appearance of motor disturbances.

The study, “Pain: A marker of prodromal Parkinsons disease?” was presented at the recent 2018 World Congress on Parkinson’s Disease and Related Disorders (IAPRD), held in Lyon, France.

Disease-related changes in patients with Parkinson’s can start decades before the onset of motor symptoms and may include pain, among other non-motor changes.

Researchers at the Bangur Institute of Neurosciences in India conducted a combined hospital and community-based study to evaluate whether pain could be an early clinical marker of future development of Parkinson’s in people with no motor impairment.

The study included a total of 500 individuals (314 men, 186 women) older than 50 from an urban community, who were examined for the prevalence of different types of pain by interviewing patients and relatives, and analyzing medical records.

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The likelihood ratio (LR) of prodromal Parkinson’s — according to the research criteria of the Movement Disorder Society — were estimated in these patients divided into two groups: a control group (LR under 80%) and a prodromal, or early, Parkinson’s group (LR above 80%).

Presence of pain was assessed in 95 patients with less than two years of disease duration and who were attending a neurology outpatient department (clinical group). Different pain syndromes were classified according to the U.S. ICD-9-CM system of diagnostic codes (the official system of assigning codes to diagnoses and procedures associated with hospital utilization in the U.S.).

Thirty-two of the 500 individuals (6.4%) had a LR consistent with early Parkinson’s. These patients showed a significantly higher prevalence of pain than the controls — 23 (71.8%) vs. 144 (30.76%), respectively.

Pain prevalence in the clinical group was 63.15%, which was comparable to the prodromal group, researchers observed.

The data also revealed that both the clinical and the prodromal groups had a higher prevalence of cervicalgia (neck pain), shoulder pain, pelvic pain, pain in the thigh joint, backache, and low back pain compared to controls.

Individuals in the clinical and prodromal groups also had more frequent frozen shoulder — characterized by stiffness and pain in the shoulder joint — restless legs syndrome (discomfort in the legs and an irresistible urge to move them), and nocturnal leg cramps.

“This is an indirect evidence that pain can be an important early clinical marker of [Parkinson’s],” the authors wrote.

However, they noted that longitudinal studies are needed to better assess the predictive value of pain in Parkinson’s disease.