Symptoms, Signs, and EEG Changes During Reflex Syncope

Abstract

studied the symptoms, video data of signs, and EEG changes during tilt-induced vasovagal syncope in 69 subjects, age range 12-84 years (mean 46 years). Reflex syncope occurred during 92 (12.8%) of a total of 720 tilt-table tests, presyncope in 101 (14.1%), and orthostatic hypotension in 84 (11.7%). The average duration of loss of consciousness was 22.4 s (range 4-55 s). EEG slowing preceded the onset of loss of consciousness. Flattening of the EEG indicates more profound circulatory changes and cerebral hypoperfusion than EEG slowing alone. 'Slow-flat-slow'-EEG is associated with a lower minimum blood pressure, longer maximum RR-interval, more frequent asystole, and longer duration of loss of consciousness than the 'slow'-EEG group.Clinical signs during syncope were of 4 types, based on their relation to the EEG: Type A signs include loss of consciousness, eye opening and general stiffening and occur during the first slow and flat phases in the EEG and end in the second slow phase. Type B signs (myoclonic jerks) occur when the EEG is slow, and are abolished with EEG flattening. Type C signs (making sounds, roving eye movements, and stertorous breathing) occur only in the EEG flat phase, whereas type D signs (dropping the jaw and snoring) occur either in slow or flat phases. The occurrence of specific clinical signs depends on whether the EEG shows flattening. Events occurring before syncope included sweating, pallor and yawning; during syncope, eyes open, dilated pupils, oral automatisms, head and jaw dropping, and arm raising; and after syncope, sweating and pallor. Whether the pattern of signs may be used to infer cause of the syncope remains to ________________________________________________________________________