More about seizure-triggered Takotsubo syndrome and SUDEP

More about seizure-triggered Takotsubo syndrome and SUDEP Response to the Letter by Madias et al. We appreciated to read the Letter to the Editor by Prof. Madias concerning ''Seizure-triggered Takotsubo syndrome rarely seems to cause SUDEP'' [1]. We do not agree with the statement that seizures after subarachnoid bleeding (SAB) are the most common central nervous system (CNS) trigger of TTS [2]. The cumulative incidence of epilepsy after spontaneous SAB is only 12% [3] and it is unknown how many of these develop TTS. The frequency of epilepsy after traumatic SAB seems to be even lower [4]. It has to be stressed, however, that spontaneous SAB in general, with and without epilepsy, is the most frequent CNS trigger of TTS [5]. We agree that we might miss minor symptomatic TTS cases. This is why we proposed to determine creatine-kinase and troponin and record an electrocardiagram in all patients with SAB, seizure, ischemic stroke, intracerebral bleeding, migraine, or encephalitis irrespective if these patients develop cardiac symptoms after the acute event or not [6]. Carrying out echocardiogra-phy in all patients with acute CNS disease is unrealistic, unless neurologists learn to do echocardiographies themselves. However, we like the speculation that future smart phone technology may allow monitoring the cardiac status after an acute CNS event. Already today sophisticated ECG machines interpret the recording themselves with high accuracy. A ''myocardial infarction pattern'' on ECG could prompt the system to ''refer'' the patient to echocardiography. However, it is conceivable that ''milder cases'' are also the ones which are not associated with cardiac complications, such as TTS or ventricular arrhythmias. Of course, as per definition, we do not know the cause of sudden unexplained death in epilepsy (SUDEP). We do know, however, that the outcome of those TTS cases which come to our attention is fair. We also know that seizure-triggered TTS, if diagnosed, has a good prognosis. From these facts we can infer that the contribution of seizure-triggered TTS to SUDEP has to be graded as low. This point of view is supported by the fact that seizures much more frequently cause ventricular arrhythmias than TTS [7], making it more likely that impulse generation or cardiac conductions defects play a more important role in the pathogenesis of SUDEP than TTS. It has to be stressed, however, that TTS may not only be complicated by arrhythmias but also by acute heart failure, asystole, thrombus formation, or …