New insights into the mechanism of neurally mediated XXXX .

@entity1 @entity551 @entity1168 @entity1163
OBJECTIVE: To determine the role of the cerebral cortex in neurally mediated @entity1163 , the electroencephalograms (EEG) of @entity1 recorded during head up tilt table test were analysed. DESIGN: Retrospective study. SETTING: University hospital. @entity1 : 18 @entity1 with @entity1163 or near @entity1163 underwent head up tilt table test with simultaneous ECG and EEG monitoring. METHODS: Standard 70 degrees tilt table test was done with simultaneous ECG and EEG monitoring. EEG waveforms were analysed by both visual inspection and spectral analysis. RESULTS: 6 of 18 @entity1 (33%) had a positive tilt table test. Before @entity1163 slow waves increased in @entity1 with a positive test. In addition, five of six tilt positive @entity1 (83%) had slow wave activity that lateralised to the left side of the brain (mean (SD) 822 (724) v 172 (215) micro V(2), p < 0.05), while none of the tilt negative @entity1 exhibited lateralisation (24 (15) v 26 (19) micro V(2), NS). Spectral analysis showed that the lateralisation occurred in the delta frequency. The lateralisation preceded the event by 5-56 seconds (18 (21) seconds). CONCLUSIONS: EEG activity lateralises to the left hemisphere of the brain before @entity1163 . The lateralisation precedes @entity1163 and is associated with the onset of @entity1168 , @entity551 , and clinical symptoms. These findings suggest that the central nervous system may have a role in neurally mediated @entity1163 .
