AltitudeOmics: Decreased reaction time after high altitude cognitive testing is a sensitive metric of hypoxic impairment.
Humans experiencing hypoxic conditions exhibit multiple signs of cognitive impairment, and high altitude expeditions may be undermined by abrupt degradation in mental performance. Therefore, the development of psychometric tools to quickly and accurately assess cognitive impairment is of great importance in aiding medical decision-making in the field, particularly in situations where symptoms may not be readily recognized. The present study used the Defense Automated Neurobehavioral Assessment (DANA), a ruggedized and portable neurocognitive assessment tool, to examine cognitive function in healthy human volunteers at sea level, immediately after ascending to an elevation over 5000 m, and following 16 days of acclimatization to this high altitude. The DANA battery begins with a simple reaction time test (SRT1) which is followed by a 20-min series of complex cognitive tests and ends with a second test of simple reaction time (SRT2). Tabulating the performance scores from these two tests allows the calculation of an SRT change score (dSRT=SRT1-SRT2) that reflects the potential effect of mental effort spent during the 20-min testing session. We found that dSRT, but not direct SRT in comparison to sea-level baseline performance, is highly sensitive to acute altitude-related performance deficits and the remission of impairment following successful acclimatization. Our results suggest that dSRT is a potentially useful analytical method to enhance the sensitivity of neurocognitive assessment.
AnthroTronix Incorporated, Silver Spring, Maryland.
Emma B
EB
Roach
National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, Maryland.
Joseph
J
Bleiberg
AnthroTronix Incorporated, Silver Spring, Maryland.
Corinna E
CE
Lathan
AnthroTronix Incorporated, Silver Spring, Maryland.
Lawrence
L
Wolpert
Wounded, Ill and Injured Directorate, US Navy Bureau of Medicine and Surgery, Falls Church, Virginia.
Jack W
JW
Tsao
Department of Emergency Medicine, Altitude Research Center, University of Colorado, Denver, Colorado, USA.
Robert C
RC
Roach