International Journal of Cardiology 179 (2015) 502–503
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Letter to the Editor
Ictal asystole and syncope Vijairam Selvaraj ⁎, Shanmugam Uthamalingam, James Murphy, Doris Kampe, Marshal T. Fox, William J. House, James R. Cook Baystate Medical Center, Springfield, MA, United States
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Article history: Received 29 October 2014 Accepted 4 November 2014 Available online 6 November 2014 Keywords: Syncope Seizures Loss of consciousness SUDEP Asystole
To the Editor, Syncope is an abrupt loss of consciousness usually followed by spontaneous recovery in seconds. In young adults, it is often attributed to vasovagal or autonomic mechanisms whereas in older patients, cardiac arrhythmias are often implicated. Seizures are always considered in the differential as a neurologic etiology in patients who present with loss of consciousness. Rarely, syncope can be seizure induced. Ictal asystole (IA) is a rare entity that when seen is often in patients with temporal lobe epilepsy, and is one possible mechanism of sudden unexpected death in epilepsy (SUDEP). IA is noted to occur in 0.3–0.4% of patients during long term video EEG and is believed to be a sinus arrest triggered by an epileptic seizure [1]. We describe a case of a 37 year old woman with multiple syncopal episodes since 2011 characterized by a smell of burning rubber or a sense of drowning followed by a brief loss of consciousness with quick return to baseline. Her husband described cessation of activity and loss of muscle tone. She has no known risk factors for epilepsy. She had an extensive workup done at another hospital with ambiguous results prior to admission here in 2014 including brain MRI, EEGs and Holter monitoring. Her symptoms were attributed to a seizure disorder for which she was placed on Carbamazepine, Levetiracetam and Valproic acid without adequate control. She reported being on a cardiac ⁎ Corresponding author at: 759 Chestnut St S2570, Baystate Medical Center, Springfield, MA 01199, United States. E-mail address:
[email protected] (V. Selvaraj).
http://dx.doi.org/10.1016/j.ijcard.2014.11.040 0167-5273/© 2014 Elsevier Ireland Ltd. All rights reserved.
medication in the past although this was discontinued as there was no benefit. She did not complain of anginal symptoms during any of the episodes. She was admitted with Neurology and Cardiology consulted. Holter tracings showed that patient was in sinus bradycardia followed by runs of intermittent junctional bradycardia at rates of 50 per minute. However, there were no visible episodes of asystole, pauses, high degree AV block. The patient underwent 4 h of continuous video EEG monitoring that was accompanied by single channel EKG. She had one typical event that began with rhythmic theta activity that started to build in amplitude then slowed in frequency, following which the patient pushed the event button (Fig. 1). Her heart rate increased to 84 beats per minute before slowing to 50 beats per minute, and then to 17 s of asystole during which she lost muscle tone and consciousness (Fig. 2). She then began to rouse and quickly recovered with EKG showing return of cardiac activity. Her syncopal episodes resolved following implantation of pacemaker although continued to have mild burning in her nose that she associated with previous seizures. It is often challenging to distinguish cardiac from epileptic causes of loss of consciousness. Partial or generalized seizures are more likely known to cause tachycardia and only in rare instances, bradycardia or even asystole [2]. Attacks of IA are noted to be clinically characterized by the loss of muscle tone or brief arrhythmic bilateral upper extremity posturing and jerking distinct from but often confused with the rhythmic, tonic–clonic posturing seen typically in epileptic seizures that are not associated with cardiac arrhythmias [3]. There have also been reports with stereotypical prodromes that are associated with IA [4]. The pathophysiology, although uncertain, is believed to be related to the cortical control of the autonomic system causing sinus node arrest. It has been studied intra-operatively in humans using intracerebral EEG recording with electrodes in the temporal, frontal and insular regions in addition to the hippocampus, amygdala, orbitofrontal cortex and anterior cingulate gyrus. Although most studies have documented left hemispheric localization, there is no clear evidence of a lateralization pattern [5]. Activation of the left mesial temporal area and/or ipsilateral posterior gyrus of the insula have been strongly related to effects on the parasympathetic tone [6]. Vagally mediated mechanisms through the left cingular gyrus have also been reported [7] although there is a role of sympathetic inhibition as well [8]. Frontal lobe tumors [9] and certain infectious encephalitis are other causes that have been described in the literature. In our case, our patient described having a characteristic prodrome following by the loss of muscle tone and consciousness with no jerking
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Fig. 1. Concomitant video EEG–EKG screenshots showing rhythmic theta activity over the right frontotemporal leads consistent with onset of seizure activity in patient (arrow head).
Fig. 2. Concomitant video EEG–EKG screenshots showing bradycardia and then asystole followed by diffuse attenuation of the theta waves and then diffuse delta activity, 2 s before return of cardiac activity.
movements. In order to deliver optimum treatment, an accurate diagnosis of IA must be made using simultaneous long term video EEG– EKG monitoring. Long term subcutaneous EKG or loop recorders have also been useful in selected cases [10]. Treatment is two-fold and usually requires implantation of pacemaker and initiation of anti-epileptic drugs. Although well described in the neurologic literature, there is a lack of awareness among non-neurologists including cardiologists regarding this phenomenon. Our case highlights the importance of being aware and recognizing the clinical cues suggestive of IA for early detection and initiation of treatment in order to avoid lethal consequences.
Conflict of interest The authors report no relationships that could be construed as a conflict of interest.
References [1] S.I.J. Schuele, A.C. Bermeo, A.V. Alexopoulous, et al., Video-electrographic and clinical features in patients with ictal asystole, Neurology 69 (2007) 434–441. [2] F. Leutmezer, C. Schernthaner, S. Lurger, et al., Electrocardiographic changes at the onset of epileptic seizures, Epilepsia 44 (2003) 348–354. [3] G.R. Ghearing, T.M. Munger, A.S. Jaffe, et al., Clinical cues for detecting ictal asystole, Clin. Auton. Res. 4 (2007) 221–226. [4] J. Novy, A. Carruzzo, P. Pascale, et al., Ictal bradycardia and asystole: an uncommon cause of syncope, Int. J. Cardiol. 133 (2009) e90–e93. [5] J.W. Britton, G.R. Ghearing, E.E. Benarroch, et al., The ictal bradycardia syndrome: localization and lateralization, Epilepsia 47 (2006) 737–744. [6] H. Catenoix, F. Mauguière, M. Guénot, et al., Recording the insula during ictal asystole, Int. J. Cardiol. 169 (2013) e28–e30. [7] H. Leung, K. Schindler, P. Kwan, et al., Asystole induced by electrical stimulation of the left cingulate gyrus, Epileptic Disord. 9 (2007) 77–81. [8] H. Leung, P. Kwan, C.E. Elger, Finding the missing link between ictal bradyarrhythmia, ictal asystole, and sudden unexpected death in epilepsy, Epilepsy Behav. 9 (2006) 19–30. [9] B.M. Van der Sluijs, W.O. Renier, A.C. Kappelle, Brain tumour as a rare cause of cardiac syncope, J. Neurooncol. 67 (2004) 241–244. [10] A. Zaidi, P. Clough, P. Cooper, et al., Misdiagnosis of epilepsy: many seizure-like attacks have a cardiovascular cause, J. Am. Coll. Cardiol. 36 (2000) 181–184.