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Hyperthermia does not affect the increase in cerebral perfusion during a cognitive task
Author(s) -
Schlader Zachary J.,
Lucas Rebekah A.I.,
Pearson James,
Crandall Craig G.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.1203.4
Subject(s) - hyperthermia , middle cerebral artery , cerebral blood flow , medicine , effects of sleep deprivation on cognitive performance , perfusion , anesthesia , cognition , cardiology , psychology , ischemia , neuroscience
This study tested the hypotheses that hyperthermia impairs the capacity to increase cerebral perfusion to a cognitive task (i.e., activation‐flow coupling) and that changes in activation‐flow coupling are related to decrements in cognitive performance during hyperthermia. Changes in mean middle cerebral artery blood velocity (MCAv mean ) served as an index of cerebral perfusion, while the nBack test (a test of working memory) was the measure of cognitive performance. The activation‐flow coupling response to the nBack test was compared between normothermia and hyperthermia. Hyperthermia increased intestinal temperature by 1.3 ± 0.1°C and reduced MCAv mean by 15 ± 14%. nBack test performance was unaffected by hyperthermia (P=0.28). The relative increase in MCAv mean to the nBack test was not different between thermal states (normothermia: 18 ± 12%; hyperthermia: 18 ± 11%, P=0.61); while activation‐flow coupling was unrelated to nBack test performance during normothermia (r=0.05, P=0.65) and hyperthermia (r=0.04, P=0.70). These data indicate that activation‐flow coupling to a cognitive challenge involving working memory is unaffected by hyperthermia. It remains to be determined whether heat stress alters activation‐flow coupling responses to tests involving different cognitive domains; particularly those that are impaired by hyperthermia. Supported by NIH Grant HL061388