High signal intensity on magnetic resonance imaging is a better predictor of neurobehavioral performances than blood manganese in asymptomatic welders.
OBJECTIVE
The aim of the study was to evaluate subclinical neurological effects in welders, using an extensive list of neurobehavioral batteries and determine if there is a link between pallidal index (PI) and subclinical neurobehavioral effects in the spectrum of manganese (Mn) symptomatology.


METHODS
A total of 43 asymptomatic male welders and 29 age- and sex-matched healthy control individuals completed questionnaires, and underwent blood examinations, brain magnetic resonance imaging (MRI) scans, and a wide range of neurobehavioral examinations.


RESULTS
Digit symbol, auditory verbal learning test (delayed recall), complex figure test (copy and immediate recall), digit span, verbal fluency test, Stroop test, grooved pegboard, finger tapping, frequency dispersion and harmonic index of tremor, and maximum frequency of hand coordination showed differences between welders and control individuals. No differences were noted for simple reaction time, postural sway, smell test, and profile of mood states (POMS). Blood Mn levels were shown to be significantly associated with grooved pegboard (dominant hand) and complex figure test (copy) results. PI was significantly associated with digit symbol, digit span backward, Stroop Word and Stroop error index, and grooved pegboard (dominant hand) results.


CONCLUSIONS
The present findings that there were significant correlations between several neurobehavioral deficits and PI as well as blood Mn suggest that they may be attributed to Mn exposure in welding fumes. The present study also shows that PI is a better predictor of neurobehavioral performance than blood Mn levels in asymptomatic welders.
Department of Molecular Medicine, Kyungpook National University College of Medicine, Kyungpook National University Hospital, Daegu, South Korea.
Yongmin
Y
Chang
Yangho
Y
Kim
Seung-Tae
ST
Woo
Hui-Jin
HJ
Song
Suk Hwan
SH
Kim
Hun
H
Lee
Young Joo
YJ
Kwon
Joon-Ho
JH
Ahn
Sin-Jae
SJ
Park
In-Sung
IS
Chung
Kyoung Sook
KS
Jeong
D000328:Adult; D000339:Affect / Q000187:drug effects; D000704:Analysis of Variance; D016022:Case-Control Studies; D003071:Cognition / Q000187:drug effects; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008345:Manganese / Q000097:blood*; D020149:Manganese Poisoning / Q000097:blood / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009460:Neurologic Examination / Q000379:methods; D009483:Neuropsychological Tests; D016273:Occupational Exposure; D011237:Predictive Value of Tests; D011597:Psychomotor Performance / Q000187:drug effects; D012044:Regression Analysis; D012903:Smell / Q000187:drug effects; D011795:Surveys and Questionnaires; D014896:Welding
D008345:Manganese