One of the biggest complaints I hear from people in PD support groups is a continuous relentless severe leg pain. Prior to a decade ago, I as all my fellow movement disorder specialist would have not thought leg pain to be a direct precursor of PD or an initial non-motor symptom. My grandmother often complained of pain and deep aches in her calves and in her legs which started before her tremors and shuffling were noticeable. But, I was unaware of the connection at the time and erroneously assumed her pain was neuropathic in nature due to her diabetes but was always somewhat surprised that she continue to complain of this pain on and off throughout her illness despite neuropathic medication. With hind sight what she was experiencing was central pain of PD. I too had severe pain first in one leg then the other which would come on suddenly without warning stopping me in my tracks throughout the day. I was constantly asking my husband to massage my legs just as my grandmother had asked of us time and time again.
So why do we have leg pain in PD and what can we do to relieve the discomfort?
First, some believe that lower limb pain is a specific non-motor phenotype variant of central pain in Parkinson’s disease. I, too, believe this; more importantly it can be one of the very first signs of PD as it was for me. This pain is usually bilateral.
Second, leg pain can also occur secondary to dystonia as an initial symptom or as a consequence of long term levodopa use (most common). When related to levodopa it usually occurs as a wearing off but can also occur at peak dose. In most cases this leg pain is unilateral and has direct correlation to medication intake. When is due to dystonia pain is more common in early morning. This type of leg pain is usually accompanied by toes curling and foot abnormally posturing.
Third, musculoskeletal pain due to rigidity, abnormal posturing and lack of mobility affects legs commonly causing pain in the legs, however this pain is usually more pronounced on the more affected side.
Fourth, pain in legs can also be caused by radiculopathy; nerves can become trapped or temporarily pinged in the spine or as they exit the spinal canal due to stiffness/rigidity of the muscles which exert an abnormal lordotic (curvature) of spine. Once again, this type of pain is usually confined to only on one side of the body and is positional meaning it is worst with standing and sitting and relieved by laying down. Pain usually radiates from back or hip down to leg and can also get worst with coughing or straining.
Fifth, pain in legs can also be due to medication effects or withdrawal from certain types of medicines like NEUPRO. In the latter, the pain which can be in both legs is more cramping.
Sixth, Let’s us not forget that we do not live in a vacuum and that just because we have PD does not make us immune to other common diseases such as peripheral vascular disease (PAD). Men are more likely to have this but women are not exempt. Risk factors include diabetes (remember PD may increase this risk), high blood pressure (again some PD meds may increase this risk), heart disease, high cholesterol, smoking, stroke, kidney disease.
The symptoms of this are:
– walking fast or uphill or for long periods to point of hurting immediately when walking
-Feet and legs feel numb at rest and skin is pale and cool to touch
Symptoms are worse with elevating legs and better with dangling over the bed.
Sometimes pain in legs can be a combination of all of the above.
Pain can be the most disability of all PD features interfering with all activities of living. Despite this fact it is often under treated and frequently overlooked. Any pain in PD should be promptly and effectively treated especially that of leg pain before the pain becomes chronic and your brain reorganizes itself completely to be able to handle the pain. I feel terrible because I did not fully understand the phenomena of central pain in PD at the time of caring for my grandmother. Fortunately, with adjustment of her levodopa meds her pain subsided for the most part. As I said before we have come a long way in understanding pain in PD, so there should be no reason why anyone should be subjected to dealing with pain on a daily basis when we have so many treatment options.
Treatments therefore depend on properly identifying the source of pain.