Neurophysiologic monitoring, including quantitative EEG, transcranial
Doppler (TCD) ultrasound and transcranial near-infrared spectroscopy (
NIRS), can be of diagnostic value in neurocardiology--the study of dys
functional bl ain-heart relationships. A new multivariate EEG techniqu
e bispectral analysis, enables the cardiologist to objectively and pre
cisely document transient episodes of syncope and seizure. TCD permits
precise determination of the nature and extent of cerebral hemodynami
c irregularities, while NIRS detects frontal lobe imbalance in the del
ivery and consumption of oxygen. These powerful new neurophysiologic f
ools, coupled with traditional systemic hemodynamic and electrocardiog
raphic measures, will undoubtedly improve the diagnostic yield in the
complex determination of the causes of syncope and cardiac-based confu
sional stales. (J Interven Cardiol 1998;11:197-204).