Neurovascular contact and blood pressure response in young, healthy, normotensive men.
BACKGROUND
Neurovascular contact (NVC) of the left rostral ventrolateral medulla has been implicated in the pathogenesis of "essential" hypertension, and recent studies suggest that this anomaly may be genetically determined. We therefore assessed the prevalence of this vascular anomaly in young normotensive volunteers. We also studied blood pressure, heart rate reactivity, and changes in baroreflex sensitivity in response to mental and physical stress in a subset of subjects with positive and negative brainstem findings.


METHODS
Magnetic resonance imaging of the brainstem was performed in 113 young (aged 25 +/- 8 years), normotensive male volunteers. Baroreflex sensitivity was then assessed in 13 subjects with positive brainstem findings and 20 subjects with negative findings.


RESULTS
Left-sided NVC was found in 19 subjects. Blood pressure levels, heart rate, and baroreflex sensitivity were similar in all groups. However, modulation of baroreflex sensitivity was reduced under mental and physical stress in subjects with a positive finding for NVC. Subjects with a positive finding also had a significantly lower body mass index than those with a negative finding.


CONCLUSIONS
Left-sided NVC is present in approximately one-fifth of young normotensive men, and may modulate the baroreceptor reflex under stress in these individuals.
Hohenbleicher
Henriette
H
Department of Internal Medicine, Division of Endocrinology and Nephrology, Universitätsklinikum Benjamin Franklin, Berlin, Germany.
Schmitz
Stephan Albert
SA
Koennecke
Hans-Christian
HC
Offermann
Jens
J
Offermann
Ralf
R
Wolf
Karl-Jürgen
KJ
Distler
Armin
A
Sharma
Arya M
AM
D000328:Adult; D000375:Aging / Q000502:physiology*; D017704:Baroreflex; D001794:Blood Pressure / Q000502:physiology*; D001933:Brain Stem / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005930:Glossopharyngeal Nerve; D006339:Heart Rate; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009408:Nerve Compression Syndromes / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012016:Reference Values; D013312:Stress, Physiological / Q000503:physiopathology; D013315:Stress, Psychological / Q000503:physiopathology; D014630:Vagus Nerve