doi:10.1093/brain/awu086
Brain 2014: 137; 1–3
| e284
BRAIN A JOURNAL OF NEUROLOGY
LETTER TO THE EDITOR Syncope and electroencephalography John B. P. Stephenson Fraser of Allander Neurosciences Unit, Royal Hospital for Sick Children, and University of Glasgow, Glasgow UK
Sir, van Dijk and colleagues have made an impressive scientific analysis of the relation between the clinical features during head-up-tilt induced syncope in adults and the simultaneous EEG findings (van Dijk et al., 2014). In particular, these authors have drawn attention to the semiology associated with the ‘classical’ slow-flat-slow EEG pattern and with simple EEG slowing without EEG flattening. I would like to add some observations to their excellent study, based on personal experience (Stephenson, 1990) and perusal of the literature. If syncope is sufficiently severe the slow-flat-slow EEG appearance seems to be independent of age—in that it is also observed in young children—and is seen in all types of syncope, however induced. However, the exact clinical semiology seems to vary with different methods of syncope generation. For example, in Gastaut and Fischer-Williams’s (1957) predominantly adult group who had 14–15 s or more cardiac standstill induced by ocular compression while sitting, the resultant flat EEG was accompanied by sudden opisthotonus, whereas this was not usual in my series of children who had ocular compression supine (Stephenson, 1990) and was not seen at all in the latest series of adults with head-up-tilt induced syncope (van Dijk et al., 2014). The argument that myoclonic jerks are of cortical origin because they are not seen when the EEG is flat (van Dijk et al., 2014) is not convincing. Other authors have noted such jerks during the flat EEG phase (Lombroso and Lerman, 1967; Lempert et al., 1994) and I have published evidence that some of these jerks may be spasms rather than true myoclonus (Stephenson, 1990), suggesting a subcortical origin. Some neurologists may not be familiar with anoxic-epileptic seizures in which a syncope triggers an epileptic seizure
(Horrocks et al., 2005) but a rare example of ictal EEG in anoxic-epileptic seizures is worth some study in the light of the present discussion. In Fig. 1 it is evident that rhythmic brief jerk artefacts appear in both the EEG and the ECG channels while the EEG is still flat, and some seconds before rhythmic spike-wave in the EEG signals the return of cortical function. Regarding signs supposedly ‘rarely reported’, oral automatisms were described in the video study of Lempert et al. (1994), albeit precise numbers were not published. What they wrote was: ‘Motor activity other than myoclonus was observed in 33 syncopes (79%) . . . Some subjects performed repetitive purposeless movements such as lip-licking, chewing, or fumbling, which resembled epileptic automatisms.’
I also described oral automatisms in more than one case example (Stephenson, 1960). I realize that limb automatisms would have been outside the field of the video camera in van Dijk et al. (2014), but this was somewhat of a pity insofar as these automatisms might be the clinical expressions of the activity of subcortical central pattern generators (Brigo, 2011). One other minor point is that the English translations of French papers in PubMed are not necessarily correct. For example, in the French original, Gastaut et al. (1956) did not describe ‘150 cases of vago-vagal syncope’ but rather ‘150 sujets pre´sentant des syncopes vaso-vagales’. Vago-vagal syncope is rare enough to be described in individual case reports (Lewis et al., 1988)— 150 would be too many even for the clinic of the great Henri Gastaut!
Advance Access publication April 14, 2014 ß The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: [email protected]
Downloaded from http://brain.oxfordjournals.org/ at Maastricht University on July 1, 2014
Correspondence to: Prof John Stephenson, Cruachan, Hawthorn Lane, Bowmore, Isle of Islay PA43 7HR, UK E-mail: [email protected]
e284
| Brain 2014: 137; 1–3
Letter to the Editor
Downloaded from http://brain.oxfordjournals.org/ at Maastricht University on July 1, 2014
Figure 1 EEG/ECG recording showing anoxic-epileptic seizure induced by ocular compression. Each panel lasts 20 s. In the upper panel ocular compression induces instant asystole and the EEG becomes flat within 12 s (the fast deflections in the 9th and 11th channels correspond to downbeat nystagmus). In the centre panel the tonic phase of the anoxic seizure is shown on the ECG line as black ‘fuzz’ due to tonic EMG activity. Midway across the centre panel while the EEG is still iso-electric, rhythmic 2–3/s jerk artefacts are seen on EEG and ECG channels. By the lower panel, rhythmic EEG spike wave is visible, slowing towards the conclusion. Jerking lasted 28 s but the child was unresponsive for a further 8 min (reproduced with permission from Stephenson 1990, Mac Keith Press, Fig. 11.4).
Letter to the Editor
References Brigo F. Gestural automatisms during syncope: the unifying concept of central pattern generators. Epilepsy Behav 2011; 22: 416. Gastaut H, Fischer-Williams M. Electro-encephalographic study of syncope. Its differentiation from epilepsy. Lancet 1957; 273: 1018–25. Gastaut H, Navarranne P, Pitot M, Salamon G. Etude e´lectroence´phalographique des syncopes. 1. Corre´lations e´lectrocliniques chez 150 sujets pre´sentant des syncopes vaso-vagales. Rev Neurol 1956; 95: 541–2. Horrocks IA, Nechay A, Stephenson JB, Zuberi SM. Anoxic-epileptic seizures: observational study of epileptic seizures induced by syncopes. Arch Dis Child 2005; 90: 1283–7.
Brain 2014: 137; 1–3
| e284
Lempert T, Bauer M, Schmidt D. Syncope: a videometric analysis of 56 episodes of transient cerebral hypoxia. Ann Neurol 1994; 36: 233–7. Lewis NP, Fraser AG, Taylor A. Syncope while vomiting during migraine attack. Lancet 1988; 2: 400–1. Lombroso CT, Lerman P. Breathholding spells (cyanotic and pallid infantile syncope). Pediatrics 1967; 39: 563–81. Stephenson JBP. Fits and faints. London: Mac Keith Press; 1990. van Dijk JG, Thijs RD, van Zwet E, Tannemaat MR, van Niekerk J, Benditt DG, Wieling W. The semiology of tilt-induced reflex syncope in relation to the electroencephalographic changes. Brain 2014; 137: 576–85.
Downloaded from http://brain.oxfordjournals.org/ at Maastricht University on July 1, 2014
Brain 2014: 137; 1–3
| e284
BRAIN A JOURNAL OF NEUROLOGY
LETTER TO THE EDITOR Syncope and electroencephalography John B. P. Stephenson Fraser of Allander Neurosciences Unit, Royal Hospital for Sick Children, and University of Glasgow, Glasgow UK
Sir, van Dijk and colleagues have made an impressive scientific analysis of the relation between the clinical features during head-up-tilt induced syncope in adults and the simultaneous EEG findings (van Dijk et al., 2014). In particular, these authors have drawn attention to the semiology associated with the ‘classical’ slow-flat-slow EEG pattern and with simple EEG slowing without EEG flattening. I would like to add some observations to their excellent study, based on personal experience (Stephenson, 1990) and perusal of the literature. If syncope is sufficiently severe the slow-flat-slow EEG appearance seems to be independent of age—in that it is also observed in young children—and is seen in all types of syncope, however induced. However, the exact clinical semiology seems to vary with different methods of syncope generation. For example, in Gastaut and Fischer-Williams’s (1957) predominantly adult group who had 14–15 s or more cardiac standstill induced by ocular compression while sitting, the resultant flat EEG was accompanied by sudden opisthotonus, whereas this was not usual in my series of children who had ocular compression supine (Stephenson, 1990) and was not seen at all in the latest series of adults with head-up-tilt induced syncope (van Dijk et al., 2014). The argument that myoclonic jerks are of cortical origin because they are not seen when the EEG is flat (van Dijk et al., 2014) is not convincing. Other authors have noted such jerks during the flat EEG phase (Lombroso and Lerman, 1967; Lempert et al., 1994) and I have published evidence that some of these jerks may be spasms rather than true myoclonus (Stephenson, 1990), suggesting a subcortical origin. Some neurologists may not be familiar with anoxic-epileptic seizures in which a syncope triggers an epileptic seizure
(Horrocks et al., 2005) but a rare example of ictal EEG in anoxic-epileptic seizures is worth some study in the light of the present discussion. In Fig. 1 it is evident that rhythmic brief jerk artefacts appear in both the EEG and the ECG channels while the EEG is still flat, and some seconds before rhythmic spike-wave in the EEG signals the return of cortical function. Regarding signs supposedly ‘rarely reported’, oral automatisms were described in the video study of Lempert et al. (1994), albeit precise numbers were not published. What they wrote was: ‘Motor activity other than myoclonus was observed in 33 syncopes (79%) . . . Some subjects performed repetitive purposeless movements such as lip-licking, chewing, or fumbling, which resembled epileptic automatisms.’
I also described oral automatisms in more than one case example (Stephenson, 1960). I realize that limb automatisms would have been outside the field of the video camera in van Dijk et al. (2014), but this was somewhat of a pity insofar as these automatisms might be the clinical expressions of the activity of subcortical central pattern generators (Brigo, 2011). One other minor point is that the English translations of French papers in PubMed are not necessarily correct. For example, in the French original, Gastaut et al. (1956) did not describe ‘150 cases of vago-vagal syncope’ but rather ‘150 sujets pre´sentant des syncopes vaso-vagales’. Vago-vagal syncope is rare enough to be described in individual case reports (Lewis et al., 1988)— 150 would be too many even for the clinic of the great Henri Gastaut!
Advance Access publication April 14, 2014 ß The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: [email protected]
Downloaded from http://brain.oxfordjournals.org/ at Maastricht University on July 1, 2014
Correspondence to: Prof John Stephenson, Cruachan, Hawthorn Lane, Bowmore, Isle of Islay PA43 7HR, UK E-mail: [email protected]
e284
| Brain 2014: 137; 1–3
Letter to the Editor
Downloaded from http://brain.oxfordjournals.org/ at Maastricht University on July 1, 2014
Figure 1 EEG/ECG recording showing anoxic-epileptic seizure induced by ocular compression. Each panel lasts 20 s. In the upper panel ocular compression induces instant asystole and the EEG becomes flat within 12 s (the fast deflections in the 9th and 11th channels correspond to downbeat nystagmus). In the centre panel the tonic phase of the anoxic seizure is shown on the ECG line as black ‘fuzz’ due to tonic EMG activity. Midway across the centre panel while the EEG is still iso-electric, rhythmic 2–3/s jerk artefacts are seen on EEG and ECG channels. By the lower panel, rhythmic EEG spike wave is visible, slowing towards the conclusion. Jerking lasted 28 s but the child was unresponsive for a further 8 min (reproduced with permission from Stephenson 1990, Mac Keith Press, Fig. 11.4).
Letter to the Editor
References Brigo F. Gestural automatisms during syncope: the unifying concept of central pattern generators. Epilepsy Behav 2011; 22: 416. Gastaut H, Fischer-Williams M. Electro-encephalographic study of syncope. Its differentiation from epilepsy. Lancet 1957; 273: 1018–25. Gastaut H, Navarranne P, Pitot M, Salamon G. Etude e´lectroence´phalographique des syncopes. 1. Corre´lations e´lectrocliniques chez 150 sujets pre´sentant des syncopes vaso-vagales. Rev Neurol 1956; 95: 541–2. Horrocks IA, Nechay A, Stephenson JB, Zuberi SM. Anoxic-epileptic seizures: observational study of epileptic seizures induced by syncopes. Arch Dis Child 2005; 90: 1283–7.
Brain 2014: 137; 1–3
| e284
Lempert T, Bauer M, Schmidt D. Syncope: a videometric analysis of 56 episodes of transient cerebral hypoxia. Ann Neurol 1994; 36: 233–7. Lewis NP, Fraser AG, Taylor A. Syncope while vomiting during migraine attack. Lancet 1988; 2: 400–1. Lombroso CT, Lerman P. Breathholding spells (cyanotic and pallid infantile syncope). Pediatrics 1967; 39: 563–81. Stephenson JBP. Fits and faints. London: Mac Keith Press; 1990. van Dijk JG, Thijs RD, van Zwet E, Tannemaat MR, van Niekerk J, Benditt DG, Wieling W. The semiology of tilt-induced reflex syncope in relation to the electroencephalographic changes. Brain 2014; 137: 576–85.
Downloaded from http://brain.oxfordjournals.org/ at Maastricht University on July 1, 2014
