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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

Center Frequency vs. Age. Upper panels show the results of linear regression analysis in welders. The slope of the lines does not differ significantly from zero with the exception of the right sided postural tremor in which Center frequencies show an age-dependent decrease (p < 0.05). The middle panels show the results of linear regression analysis in PD subjects. None of the slopes differ significantly from zero. The lower panels (ET) indicate an age-dependent increase in postural tremor Cf on the right side. Regression line is significantly different from zero (p = 0.04).
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f4-ijerph-08-01478: Center Frequency vs. Age. Upper panels show the results of linear regression analysis in welders. The slope of the lines does not differ significantly from zero with the exception of the right sided postural tremor in which Center frequencies show an age-dependent decrease (p < 0.05). The middle panels show the results of linear regression analysis in PD subjects. None of the slopes differ significantly from zero. The lower panels (ET) indicate an age-dependent increase in postural tremor Cf on the right side. Regression line is significantly different from zero (p = 0.04).

Mentions: Regression analysis was performed on tremor intensity, and Cf as a function of age in the three groups of patients. There was no significant change in tremor intensity with age in any of the three groups (Figure 3). Linear regression analysis also showed no significant relationship between Cf and age in PD subjects. However, welders showed an age-dependent decrease in the Cf of right sided postural tremor while patients with ET showed an age-dependent increase in Cf (p = 0.04). (Figure 4) Linear regression analysis of tremor intensity (and other parameters of tremor) in welders against duration of symptoms or time last exposed to welding did not find significant relationships (Figure 5).


Quantitative analysis of tremors in welders.

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

Center Frequency vs. Age. Upper panels show the results of linear regression analysis in welders. The slope of the lines does not differ significantly from zero with the exception of the right sided postural tremor in which Center frequencies show an age-dependent decrease (p < 0.05). The middle panels show the results of linear regression analysis in PD subjects. None of the slopes differ significantly from zero. The lower panels (ET) indicate an age-dependent increase in postural tremor Cf on the right side. Regression line is significantly different from zero (p = 0.04).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4-ijerph-08-01478: Center Frequency vs. Age. Upper panels show the results of linear regression analysis in welders. The slope of the lines does not differ significantly from zero with the exception of the right sided postural tremor in which Center frequencies show an age-dependent decrease (p < 0.05). The middle panels show the results of linear regression analysis in PD subjects. None of the slopes differ significantly from zero. The lower panels (ET) indicate an age-dependent increase in postural tremor Cf on the right side. Regression line is significantly different from zero (p = 0.04).
Mentions: Regression analysis was performed on tremor intensity, and Cf as a function of age in the three groups of patients. There was no significant change in tremor intensity with age in any of the three groups (Figure 3). Linear regression analysis also showed no significant relationship between Cf and age in PD subjects. However, welders showed an age-dependent decrease in the Cf of right sided postural tremor while patients with ET showed an age-dependent increase in Cf (p = 0.04). (Figure 4) Linear regression analysis of tremor intensity (and other parameters of tremor) in welders against duration of symptoms or time last exposed to welding did not find significant relationships (Figure 5).

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