Study finds pain to be common in early-onset Parkinson’s
More severe pain linked to older age, nonmotor symptoms such as depression
More than three-quarters of people with early-onset Parkinson’s disease (EOPD) experience pain, according to a recent study conducted in Vietnam, with more severe pain reported by older patients and those with nonmotor symptoms such as depression, sexual dysfunction, and hallucinations.
Additional studies with well-validated tools are needed to further understand pain in this patient population and its interplay with other Parkinson’s symptoms, according to scientists.
“Pain may be more common and severe in EOPD patients than previously appreciated,” researchers wrote. “We hope this study will raise the astute clinician’s suspicion when a patient with EOPD presents with uncontrolled pain.”
The study, “Pain is common in early onset Parkinson’s disease and pain severity is associated with age and worsening of motor and non-motor symptoms,” was published in the Journal of the Neurological Sciences.
Pain is common Parkinson’s nonmotor symptom affecting 90% of patients
Pain is among the most common nonmotor symptoms of Parkinson’s disease, estimated to occur in nearly 90% of patients, but it frequently goes unrecognized.
This troublesome and difficult-to-define symptom is not included on standard Parkinson’s disease assessments. Thus, “reliable, repeatable and convenient measurements of pain remain underutilized in routine clinical practice,” the researchers wrote.
Particularly, pain in early-onset Parkinson’s, where disease onset occurs before age 50, remains understudied. Its exact prevalence in this population is not established.
“The lack of consensus on the prevalence of pain in patients with EOPD may be that previous studies have rarely delineated between the general population of patients with PD [Parkinson’s disease] versus patients with EOPD,” the researchers wrote.
It’s especially important to understand pain in early-onset Parkinson’s because these patients may be more likely to experience quality of life declines as a result, the researchers noted.
As such, the team set out to investigate the prevalence and severity of pain among Vietnamese patients with early-onset disease.
The analysis included 135 patients being treated at hospitals in Vietnam from 2019 to 2021. These 72 men and 63 women, with a mean age of 45.5, had been living with Parkinson’s for a mean of 7.9 years. A family history of Parkinson’s was recorded for 23 people (17%).
Pain was evaluated with the King’s Parkinson’s Disease Pain Scale (KPPS), a tool that has been validated in the general Parkinson’s disease population, but not specifically in early-onset patients. The KPPS scores pain across seven different domains, with higher scores indicating greater pain severity.
Pain may be more common and severe in [early-onset Parkinson’s disease] patients than previously appreciated.
Pain reported by 79% of patients in study
Overall, some type of pain was reported by 107 of 135 patients (79.3%), 74.8% of whom experienced more than one type of pain.
The most common type of experienced pain was musculoskeletal (70.1%), followed by nighttime pain (43.9%), pain radiating down the spine (radicular pain; 43%), chronic pain (42.1%), motor fluctuation-related pain (34.6%), swelling pain (22.4%), and face/mouth pain (orofacial; 16.8%).
Pain intensity was rated as mild for 34.6% of patients, moderate in 37.4%, and severe in the remaining 28%.
Orofacial and fluctuation-related pain were significantly more prevalent among patients with more advanced Parkinson’s motor symptoms (stages 3-5 on the Hoehn and Yahr, or HY, scale) compared to those with lower disability (HY stages 1-2).
These patients with more advanced disease also had statistically significantly higher KPPS scores in the fluctuation-related and radicular pain domains.
Additional analyses indicated older age, greater depression severity, perceptual problems/hallucinations, and sexual dysfunction were each independently associated with higher KPPS scores, or more severe pain.
Patients with depression report experiencing more severe pain
Moreover, patients with depression who were also in HY stages 3-5 had significantly higher mean KPPS scores compared with patients in HY stages 1-2 who were not depressed.
Other clinical factors, such as sex, family history, medications, and specific motor symptoms, did not significantly influence pain.
Understanding pain may be particularly important in early-onset disease patients, who are “at a stage in life where the patient still expects to retain a high standard of living,” the researchers wrote. In current practice, however, “pain is not often emphasized or uniformly assessed.”
“The results of this study bring to light the unmet clinical need in this patient population,” in addition to highlighting ” the importance of further studies of pain using a standardized pain assessment such as the KPPS,” the team concluded.
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