Document Detail


Hypohydration and muscular fatigue of the thumb alter median nerve somatosensory evoked potentials.
MedLine Citation:
PMID:  20725111     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The mechanisms by which dehydration impairs endurance performance remain unresolved but may involve alterations in afferent neural processing. The purpose of this study was to determine the effect of hypohydration on somatosensory evoked potentials (SEPs) at rest and during recovery from fatiguing exercise. Fourteen volunteers (12 men, 2 women) performed repetitive isometric thumb contractions (50% maximal voluntary contractions (MVC) and 100% MVC in a 5:1 ratio, each contraction separated by 5 s of rest) until exhaustion when euhydrated (EU) and when hypohydrated by 4% body mass (HY). SEPs were obtained from the median nerve. The results indicated that HY did not produce statistical differences in time to exhaustion (EU=754 (SD 255); HY=714 (SD 318) s; p=0.66) or rate of muscle fatigue. However, HY was associated with greater subjective feelings of fatigue and loss of vigor after exhaustive exercise (p<0.01). HY affected N20 latency with an interaction effect of hydration by fatigue state (EU-Rest: 18.5 (SD 1.6) ms; EU-Fatigue: 19.0 (SD 1.6) ms; HY-Rest: 18.3 (SD 1.3) ms; HY-Fatigue: 18.4 (SD 1.5) ms; p=0.034), but N20 and N20-P22 amplitude responses were similar between HY and EU trials. We concluded that moderate water deficits appear to alter afferent signal processing within the cerebral cortex.
Authors:
Scott J Montain; William J Tharion
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Applied physiology, nutrition, and metabolism = Physiologie appliquée, nutrition et métabolisme     Volume:  35     ISSN:  1715-5312     ISO Abbreviation:  Appl Physiol Nutr Metab     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-08-20     Completed Date:  2010-10-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101264333     Medline TA:  Appl Physiol Nutr Metab     Country:  Canada    
Other Details:
Languages:  eng     Pagination:  456-63     Citation Subset:  IM    
Affiliation:
Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, MA 01760, USA. scott.montain@us.army.mil
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MeSH Terms
Descriptor/Qualifier:
Adult
Affect
Afferent Pathways
Cerebral Cortex / physiopathology*
Dehydration / physiopathology*,  psychology
Evoked Potentials, Somatosensory*
Exercise Test
Female
Humans
Isometric Contraction*
Male
Median Nerve / physiopathology*
Muscle Fatigue*
Muscle, Skeletal / innervation*
Perception
Questionnaires
Reaction Time
Thumb
Time Factors
Young Adult

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


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