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Quantitative analysis of tremors in welders.

Sanchez-Ramos J, Reimer D, Zesiewicz T, Sullivan K, Nausieda PA - Int J Environ Res Public Health (2011)

Bottom Line: Postural tremor intensity was increased in Welders and ET and was associated with visibly greater amplitude of tremor with arms extended.Mean center frequencies (Cf) of welders and patients with ET were significantly higher than the mean Cf of PD subjects.Although both the welders and the ET group exhibited a higher Cf with arms extended, welders could be distinguished from the ET subjects by a significantly lower Cf of the rest tremor than that measured in ET subjects.

View Article: PubMed Central - PubMed

Affiliation: College of Medicine, University of South Florida, Tampa, FL 33612, USA. jsramos@health.usf.edu

ABSTRACT

Background: Workers chronically exposed to manganese in welding fumes may develop an extra-pyramidal syndrome with postural and action tremors.

Objectives: To determine the utility of tremor analysis in distinguishing tremors among workers exposed to welding fumes, patients with Idiopathic Parkinson's Disease (IPD) and Essential Tremor (ET).

Methods: Retrospective study of recorded tremor in subjects from academic Movement Disorders Clinics and Welders. Quantitative tremor analysis was performed and associated with clinical status.

Results: Postural tremor intensity was increased in Welders and ET and was associated with visibly greater amplitude of tremor with arms extended. Mean center frequencies (Cf) of welders and patients with ET were significantly higher than the mean Cf of PD subjects. Although both the welders and the ET group exhibited a higher Cf with arms extended, welders could be distinguished from the ET subjects by a significantly lower Cf of the rest tremor than that measured in ET subjects.

Conclusions: In the context of an appropriate exposure history and neurological examination, tremor analysis may be useful in the diagnosis of manganese-related extra-pyramidal manifestations.

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Related in: MedlinePlus

Flow chart showing selection of welders for the accelerometry study.
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f1-ijerph-08-01478: Flow chart showing selection of welders for the accelerometry study.

Mentions: Approximately 20,000 individuals who worked as welders or assistants in shipyards and refineries were screened for neurologic abnormalities in a union-organized effort supported by a legal consortium over a period of five years. These subjects were self-selected by responding to advertisements that listed a number of symptoms and signs associated with manganese toxicity. A team of physicians conducted screening examinations following a simple protocol designed to detect any neurologic abnormality. The majority of the subjects who had undergone the initial screening for neurologic symptoms typically did not have extrapyramidal features, but rather exhibited signs consistent with peripheral neuropathies, radiculopathies, stroke, and occasionally demyelinating disease or motor neuron disease (see Flow Chart Figure 1). Subjects with extrapyramidal signs (slowness of movement, rigidity, tremors) were then examined in subsequent visits over three years by two neurologists (PN, JSR) with expertise in Movement Disorders. As an exploratory study, JSR recorded tremor with a portable accelerometry system (CATSYS, LTD) in a sample of 37 welders or welding assistants each of whom was examined independently on the same day (by PN and JSR) and given a consensual diagnosis of probable manganism. The syndrome of manganism was inferred from the appearance of slowness, rigidity, tremors (both resting and postural), cramping or dystonia of limbs, upper motor neuron signs, and behavioral disturbances (irritability, depression) in the context of chronic exposure to welding fumes.


Quantitative analysis of tremors in welders.

Sanchez-Ramos J, Reimer D, Zesiewicz T, Sullivan K, Nausieda PA - Int J Environ Res Public Health (2011)

Flow chart showing selection of welders for the accelerometry study.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3108121&req=5

f1-ijerph-08-01478: Flow chart showing selection of welders for the accelerometry study.
Mentions: Approximately 20,000 individuals who worked as welders or assistants in shipyards and refineries were screened for neurologic abnormalities in a union-organized effort supported by a legal consortium over a period of five years. These subjects were self-selected by responding to advertisements that listed a number of symptoms and signs associated with manganese toxicity. A team of physicians conducted screening examinations following a simple protocol designed to detect any neurologic abnormality. The majority of the subjects who had undergone the initial screening for neurologic symptoms typically did not have extrapyramidal features, but rather exhibited signs consistent with peripheral neuropathies, radiculopathies, stroke, and occasionally demyelinating disease or motor neuron disease (see Flow Chart Figure 1). Subjects with extrapyramidal signs (slowness of movement, rigidity, tremors) were then examined in subsequent visits over three years by two neurologists (PN, JSR) with expertise in Movement Disorders. As an exploratory study, JSR recorded tremor with a portable accelerometry system (CATSYS, LTD) in a sample of 37 welders or welding assistants each of whom was examined independently on the same day (by PN and JSR) and given a consensual diagnosis of probable manganism. The syndrome of manganism was inferred from the appearance of slowness, rigidity, tremors (both resting and postural), cramping or dystonia of limbs, upper motor neuron signs, and behavioral disturbances (irritability, depression) in the context of chronic exposure to welding fumes.

Bottom Line: Postural tremor intensity was increased in Welders and ET and was associated with visibly greater amplitude of tremor with arms extended.Mean center frequencies (Cf) of welders and patients with ET were significantly higher than the mean Cf of PD subjects.Although both the welders and the ET group exhibited a higher Cf with arms extended, welders could be distinguished from the ET subjects by a significantly lower Cf of the rest tremor than that measured in ET subjects.

View Article: PubMed Central - PubMed

Affiliation: College of Medicine, University of South Florida, Tampa, FL 33612, USA. jsramos@health.usf.edu

ABSTRACT

Background: Workers chronically exposed to manganese in welding fumes may develop an extra-pyramidal syndrome with postural and action tremors.

Objectives: To determine the utility of tremor analysis in distinguishing tremors among workers exposed to welding fumes, patients with Idiopathic Parkinson's Disease (IPD) and Essential Tremor (ET).

Methods: Retrospective study of recorded tremor in subjects from academic Movement Disorders Clinics and Welders. Quantitative tremor analysis was performed and associated with clinical status.

Results: Postural tremor intensity was increased in Welders and ET and was associated with visibly greater amplitude of tremor with arms extended. Mean center frequencies (Cf) of welders and patients with ET were significantly higher than the mean Cf of PD subjects. Although both the welders and the ET group exhibited a higher Cf with arms extended, welders could be distinguished from the ET subjects by a significantly lower Cf of the rest tremor than that measured in ET subjects.

Conclusions: In the context of an appropriate exposure history and neurological examination, tremor analysis may be useful in the diagnosis of manganese-related extra-pyramidal manifestations.

Show MeSH
Related in: MedlinePlus