Quantitative electroencephalography characteristics of tilt-induced neurally-mediated syncope among youth.

OBJECTIVE

To characterize the quantitative electroencephalographic (QEEG) patterns associated with tilt-induced syncope in youth.

METHODS

Several QEEG parameters were analyzed. Data were calculated for peak or nadir changes with syncope for amplitude-EEG, fast Fourier transform (FFT) power in several frequency ranges, 8-13 Hz/1-4 Hz frequency ratio, and FFT edge.

RESULTS

Changes in QEEG parameters were present among all patients with tilt-induced syncope (n = 76). These changes included increases in the low frequency FFT power (1-4 Hz range), decreases in the power ratio (8-13 Hz/1-4 Hz) and decreases in the FFT edge (95%, 1-18 Hz). All patients had suppression of EEG amplitudes that closely followed loss of consciousness. Asymmetry indices demonstrated cerebral hemisphere lateralization at multiple periods during the evolution of syncope, but the side of lateralization did not differ from 0.5 probability.

CONCLUSIONS

QEEG parameters can be used to characterize EEG changes associated with tilt-induced, neurally-mediated syncope.

SIGNIFICANCE: QEEG may serve as a useful tool for the study of syncope neurophysiology, and the modeling of changes with syncope may improve our understanding of other neurologic disorders caused by defects in cerebral perfusion.