Document Detail


Quantification of neuromotor function for detection of the effects of manganese.
MedLine Citation:
PMID:  10385896     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of low level exposure to manganese (Mn) was examined in 297 subjects from southwest Quebec. Blood manganese (MnB) levels as well as other possibly relevant variables were obtained. We tested equipment and analysis procedures that we have developed to quantify aspects of motor function thought to be affected by exposure to toxins, in particular, rapid alternating movements, rapid and precise pointing movements, and tremor. (1) The eurythmokinesimeter measures timing and precision of contacts between a hand-held stylus and a pair of metal targets (proximal/distal). This roughly approximates the finger-to-nose test of the UPDRS. Characteristics quantifying speed, precision and regularity of the movements were calculated, as well as multiple contacts due to tremor and an index based on Fitts' Law eliminating the effect of the trade-off between speed and precision. (2) The diadochokinesimeter accurately measures rapid rotation of the forearms (pronation/supination). Characteristics quantifying the range, speed, period, shape and regularity of the oscillatory movements were calculated, as well as the smoothness of the movement on a fine scale and the coordination between the two hands. (3) Postural tremor of the arm and hand was measured using the accelerometry-based "TREMOR" system of Danish Product Development. We used the amplitude and frequency characteristics provided by the TREMOR system: intensity, center frequency, dispersion and harmonic index. Previous studies have shown that these tests are sufficiently sensitive to detect small differences in performance of different groups of subjects, with indications that some characteristics are also specific to particular conditions. In this study, significant though small effects related to age and gender were found in many of the characteristics. When effects of other variables are removed, low-level exposure to Mn was found to be associated with a decrease in ability to perform regular, rapid and precise pointing movements, a decrease in ability to attain high maximum rotation speeds in rapid alternating movements, and an increase in regularity of tremor oscillations. Moreover, the effects are age-related for levels of MnB 7.5, micrograms/L.
Authors:
A Beuter; R Edwards; A deGeoffroy; D Mergler; K Hundnell
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Neurotoxicology     Volume:  20     ISSN:  0161-813X     ISO Abbreviation:  Neurotoxicology     Publication Date:    1999 Apr-Jun
Date Detail:
Created Date:  1999-09-03     Completed Date:  1999-09-03     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7905589     Medline TA:  Neurotoxicology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  355-66     Citation Subset:  IM    
Affiliation:
Laboratoire de Neuroscience de la Cognition, DS-5749, Université du Québec á Montréal, Canada. beuter.anne@uqam.ca
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MeSH Terms
Descriptor/Qualifier:
Adult
Age Factors
Aged
Diagnostic Techniques, Neurological / instrumentation*
Dose-Response Relationship, Drug
Humans
Manganese / blood*
Manganese Poisoning*
Middle Aged
Motor Skills / drug effects*
Nervous System Diseases / chemically induced*,  diagnosis
Neuropsychological Tests*
Sex Factors
Statistics as Topic
Time Factors
Chemical
Reg. No./Substance:
7439-96-5/Manganese

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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