The Clinical and Electroencephalographic Spectrum of Tilt-Induced Syncope and “Near Syncope” in Youth  Geoffrey L. Heyer, MD, Caitlin Schmittauer, RN, Monica P. Islam, MD  Pediatric Neurology  Volume 62, Pages 27-33 (September 2016) DOI: 10.1016/j.pediatrneurol.2016.05.007 Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 1 Blood pressure changes with delayed orthostatic hypotension without syncope. An abrupt blood pressure drop (greater than 20 mm Hg) occurred at 992 seconds of head-upright tilt and persisted through table lowering at 1087 seconds. Table lowering takes an additional 12 seconds. Corresponding electroencephalographic changes were present for 51 seconds. Pediatric Neurology 2016 62, 27-33DOI: (10.1016/j.pediatrneurol.2016.05.007) Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 2 Electroencephalographic (EEG) slowing during a period of delayed-onset hypotension without syncope. This patient endured a period of hypotension lasting about 70 seconds with corresponding EEG slowing of 48 seconds. She was able to answer three of four questions correctly, but her responses were delayed by several seconds. Upon recovery, she described the period as “like a dream” and identical to past episode where syncope did not occur. Pediatric Neurology 2016 62, 27-33DOI: (10.1016/j.pediatrneurol.2016.05.007) Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 3 Most patients with delayed hypotension without syncope had corresponding electroencephalographic (EEG) slowing. The periods of EEG slowing from onset to table lowering exceeded the periods of EEG slowing from onset to loss of consciousness among the patients with syncope (slow-flat-slow and slow-only patterns). The very long relative periods of hypotension with EEG slowing argue against typical presyncope as the cause of hypotension. In addition, the slow-flat-slow group of syncope patients had a significantly briefer interval from EEG slowing to clinical syncope than the slow-only group. Pediatric Neurology 2016 62, 27-33DOI: (10.1016/j.pediatrneurol.2016.05.007) Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 4 The slow-flat-slow syncope pattern on electroencephalographic (EEG) has distinctive clinical features. Letter headings (A to G) mark each EEG phase. Hypotension is the first clinical sign. (A) Asystole begins. (B) The first phase of EEG slowing begins. (C) Slumping of the shoulders and gaze shifted upward (without substantial head drop) indicate loss of consciousness. This is followed by a single myoclonic jerk. (D) EEG slowing transitions to flattening. There is head and conjugate eye turning to the left, followed rapidly by flexor posturing. The first QRS wave following asystole is seen. (E) EEG flattening transitions to the second slow phase. (F) A series of myoclonic jerks, groaning vocalizations, and lip smacking occurs. These movements are marked, in part, by muscle artifact on EEG. (G) EEG slowing begins to normalize as the patient recovers. Pediatric Neurology 2016 62, 27-33DOI: (10.1016/j.pediatrneurol.2016.05.007) Copyright © 2016 Elsevier Inc. Terms and Conditions