“Twenty years ago, I received a diagnosis of Parkinson’s disease. I was forty-three … it occurred to me to wonder whether it would affect my brain. I asked my neurologist at the time, and he answered carefully, “Well, after a few years you may lose your edge.” Lose my edge? Lose my edge? Oh, shit! I need my edge. My edge is how I make a living. More than that: My edge is my claim on the world. It’s why people are my friends, why they invite me over for dinner …” “Even after twenty years, if I take my meds I can seem almost symptom-free for most of the day … a standard-issue baby-boomer bad back has been more burdensome to me than Parkinson”.
James Parkinson first described the condition that became synonymous with his name, in ‘An Essay in the Shaking Palsy‘ in 1817. Since then, the motor symptoms of Parkinson’s have been its defining feature – tremor, bradykinesia, rigidity … and understandably so. But many non-motor signs remain unnoticed and unexpected – pain being one of them. The above excerpt from The New Yorker gives some insight into this oversight. Although 30-85% of people with PD experience pain, it is under-reported (see this 2017 review in Nature for an exploration of non-motor PD signs).
As with all pain states, to effectively treat pain we need to understand the mechanisms underlying it. This is where a simple to use and administer scale comes in handy. So in 2015, Chaudhuri et al. (open access) created and validated the first scale to identify and grade various types of pain in PD. The King’s Parkinson’s Disease Pain Scale (KPPS) has 14 questions relating to 7 categories. It factors in both severity and frequency, taking around 10-15 mins to administer. As a result, it classifies pain in PD to musculoskeletal, fluctuation related, central, nocturnal orofacial and peripheral pain.
We know that pain fluctuates with a patients motor state, so keep in mind this was tested during their ‘on’ phase. Perhaps using this scale to classify pain can help with the initiation of individualised therapies. Would this come in handy for your clinical practice?
– Hayley Leake