Mayo Clinic links welding and brain damage cases
June 8, 2005
For the first time, a Mayo clinic series analysis has identified syndromes associated with toxic damage to the brain and nervous system from manganese fumes generated during welding. The analysis also revealed that all affected patients shared a risk factor, which was welding with inadequate ventilation.
Because of ethical problems, human trials with manganese fume exposure are not conducted, so most information regarding welding health risks is from animal studies or from analyzing patient cases where exposure has already occurred. Mayo Clinic researchers examined medical records from eight patients referred to the clinic between 1999 and 2005 for a variety of nervous system complaints.
In every MRI scan, there was an area of increased T1 signal intensity in the basal ganglia region of the brain, appearing as a bright spot on the MRI scan. The bright spot is a biological indicator of manganese accumulation, and all men had been involved in welding for one to 25 years before symptoms developed.
Manganese exposure symptoms varied initially, but over time, multiple symptoms developed, including cognitive impairment, headaches and tremor in six of the patients. Balance problems also appeared in five patients, and each patient was diagnosed with neurotoxicity from welding fumes after undergoing tests appropriate to each patient's individual complaints, which included both blood and urine testing, brain MRI and psychological testing of intelligence, aptitude and personality traits.
Mayo Clinic neurologist, Keith Josephs, M.D., who fronted the analysis, said the increased T1 signal in the brains of the eight patients shown in the MRIs is an uncommon finding in brain imaging, showing the first case series of welders with the abnormal signal highlighting a widespread neurological impairment. In the past, Josephs said previous case reports linked manganese fumes generated by welding with various symptoms, but never before identified the syndromes of actual diagnoses, with exception to parkinsonism.
Identified in the Mayo Clinic analysis, syndromes developed from manganese fumes generated during welding included Parkinsonian syndrome, multifocal myoclonus, vestibular-auditory dysfunction and mild cognitive impairment. In addition, patients showed minor symptoms of anxiety, irritability, shakiness and sleep disorder. Among all eight welders studied, the common factor was inadequate fume protective measures.
The case series is more evidence of the dangers unprotected welding can produce, leading to neurological damage. The U.S. Department of Labor's Occupational Safety and Health Administration sets workplace guidelines that limits exposure to potentially harmful risks, including manganese fumes. When not closely adhered to, the Mayo Clinic case series highlights the grave dangers and toxic effects the welders endure.
Although there are treatment options available for manganese neurotoxicity, many of the patients studied still had symptoms after they stopped exposing themselves to welding fumes. The Mayo Clinic neurologists, as a result, suggested the damage suffered by manganese exposure could be permanent. According to Josephs, the best treatment option for patients suffering manganese neurotoxicity may be removal from welding because of the possible static or progressive damage.
Workplace standards exist to keep welders safe. If you have been exposed to unsafe levels of manganese because of insufficient safeguards, please contact us to confer with an attorney.
