Cerebrovascular dynamics and vascular endothelial growth factor in acute mountain sickness.
OBJECTIVE
To determine if serum vascular endothelial growth factor (VEGF) and ultrasonic monitoring of vascular dynamics with dynamic vascular analysis at sea level and high altitude correlate with acute mountain sickness symptoms.


METHODS
Nine volunteers participated in a staged ascent from sea level to 4300 m undergoing complete transcranial Doppler studies with dynamic vascular analysis. Serum VEGF levels, Lake Louise scores, Spielberger-1 scores, Subjective Exercise Experiences Scale positive scores, and Symptom Checklist-90 surveys were collected after 24 hours at each altitude.


RESULTS
Symptom scores, index of pulsatility, and dynamic flow index differentiated the subjects into 2 distinct groups. Symptomatic subjects had increased VEGF levels at sea level but decreased levels at 4300 m. The dynamic flow index increased in symptomatic subjects at 4300 m compared with the asymptomatic subjects. The mean flow velocity increased in both groups and could not be used to differentiate the subjects.


CONCLUSIONS
Altered vascular physiology is associated with acute mountain sickness. Increased vascular permeability increases vascular capacitance, with an increase in dynamic flow index to meet these demands. Altered vascular dynamics were associated with high-altitude cerebral edema in 1 subject. Dynamic vascular analysis demonstrated altered vascular pathophysiology associated with acute mountain sickness. Changes in VEGF were meaningful when interpreted with the dynamic vascular analysis findings. These physiological findings may help explain the vascular changes associated with hypocarbic hypoxemia at altitude.
Department of Military and Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
Joseph
J
Palma
Christian
C
Macedonia
Patricia
P
Deuster
Cara
C
Olsen
B Robert
BR
Mozayeni
Kevin E
KE
Crutchfield
D000208:Acute Disease; D000328:Adult; D000532:Altitude Sickness / Q000097:blood / Q000503:physiopathology*; D001929:Brain Edema / Q000097:blood; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D010865:Pilot Projects; D011446:Prospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
D042461:Vascular Endothelial Growth Factor A