Abstracts

Rationale: The pathophysiology of sudden unexpected death in epilepsy (SUDEP) is poorly understood and likely multifactorial. The cascade of events in SUDEP includes varying respiratory and cardiac components, which may occur with or without a preceding seizure (Ryvlin et al., 2013, Lhatoo et al., 2016). Understanding patterns and variations in SUDEP mechanisms is crucial to developing effective interventions to promote survival and neurological recovery. Comparing the outcomes of resuscitative efforts in SUDEP may illuminate the pathophysiology of SUDEP. In the MORTEMUS study, seven patients survived SUDEP with cardiopulmonary resuscitation (CPR) within three minutes (Ryvlin et al., 2013). Conversely, in two SUDEPs in medical settings, even prompt administration of advanced cardiovascular life support (ACLS) failed to prevent SUDEP (Swinghamer et al., 2012). Here we report six cases of resuscitated ("near") SUDEP among participants in the North American SUDEP Registry (NASR), a clinical and biorepository created to advance SUDEP research. Methods: As of June 1, 2016, 313 participants were enrolled in the NASR. Cases are referred by bereaved family members, neurologists, medical examiners, and support groups. Medical records and family member interviews are collected for most cases and SUDEP classification is determined by the consensus of two epileptologists using criteria of Nashef et al. (2012). Medical and death records were examined for cases meeting "near-SUDEP" criteria. Results: 73 cases were reviewed, of which six (8.2%) met criteria for near-SUDEP. Four (66.7%) were female and the median age was 26.5 years (range: 11-34 years). Decedents varied clinically (Table 1), but for most, duration of epilepsy was short (median: 3 years) and etiology was unknown (66.7%). Five (83.3%) had fewer than ten generalized tonic-clonic seizures in their lifetime. The circumstances of the cardiorespiratory arrest (CRA) and CPR also varied between cases (Table 2). The CRA itself was witnessed in only one case, in which CPR was immediate. All cases were in asystole when ACLS was initiated, of whom 83.3% were out-of-hospital and first given CPR by a trained or untrained bystander. The only in-hospital case was alone and unmonitored at the time of CRA. In all cases, life support was withdrawn in the context of brain death. Conclusions: The lack of near-SUDEP survivors in our cohort likely reflects selection bias from the referral process. This minority of cases were able undergo resuscitation and did not fit the prototypical SUDEP case profile, suggesting that there is a pathophysiology that is potentially more responsive to resuscitative efforts. However, our findings also illustrate that even in a witnessed SUDEP event with immediate CPR by trained bystanders, a meaningful recovery is not always possible. In all cases, only ACLS was able to produce a sustained reversal of the arrest. Efforts should be made to develop detectors for the respiratory and cardiac patterns that occur before CRA in SUDEP to promote immediate transport of the patient to an advanced care facility. Funding: Finding a Cure for Epilepsy and Seizures (FACES)