There has long been a fascination about the relationship between welding, mining and Parkinson-like symptoms. In this month’s What’s Hot blog and in my NEJM Journal Watch blog I explore this murky history and relationship. Doctors and health care professionals long ago identified a Parkinson-like syndrome that developed in welders and manganese miners. Manganese, the chemical, has been linked to Parkinson-like symptoms (also referred to as parkinsonism). Manganese exposure related to parkinsonism symptoms dates back to the late 1960s and early 1970s.
Once the Parkinson-like syndrome has been diagnosed, there is debate as to whether it is progressive (worsens over time). Recently, Brad Racette, MD, and colleagues at Washington University in St. Louis, MO, published an important paper on the subject in Neurology. Over a period of about 10 years, Dr. Racette repeatedly observed and examined 886 welders who were members of a trade union. Their work history was used to determine exposure to manganese. The study revealed that the cumulative manganese exposure was related to Parkinson-like progression. The change in the UPDRS motor scale (the scale used to measure motor disability in Parkinson’s) was 0.24 per year for each milligram of manganese exposure.
Upper limb bradykinesia, upper and lower limb rigidity, impairment of speech and facial expression showed the highest, or worst, values. The study authors concluded that flux core welding in a confined space had the greatest risk for disease progression.
The primary take-home point of this study is that people with existing dopamine-responsive Parkinson’s who are not exposed to manganese in a mine or through welding should not apply the results to themselves. It is a very rare syndrome. If you were exposed to manganese, then these results may apply to your case. Welders and manganese miners are at a higher risk of developing symmetric parkinsonism (which occurs in both sides of the body, without a worse side); there is commonly also a high stepping gait and changes on the T1 MRI brain sequence. Other exposures such as carbon monoxide and solvents can also cause the syndrome. You should share your mining or welding history with your doctor and, if diagnosed, be aware that this may be a progressive syndrome.
- Racette BA, Searles Nielsen S, Criswell SR, Sheppard L, Seixas N, Warden MN, Checkoway H. Dose-dependent progression of parkinsonism in manganese-exposed welders. Neurology. 2016 Dec 28. pii: 10.1212/WNL.0000000000003533. doi: 10.1212/WNL.0000000000003533. [Epub ahead of print] PubMed PMID: 28031394.
- Okun MS. Progression of Parkinsonism and the Importance of Exposure to Manganese in Welders. NEJM Journal Watch, 2017.
You can find out more about PF's National Medical Director, Dr. Michael S. Okun, by also visiting the Center of Excellence, University of Florida Health Center for Movement Disorders and Neurorestoration. Dr. Okun is also the author of the Amazon #1 Parkinson's Best Seller 10 Secrets to a Happier Life and 10 Breakthrough Therapies for Parkinson's Disease. You can read more from Dr. Okun in the What's Hot in PD? archives.