Abstracts

Rationale: Neurogenic pulmonary edema (NPE) is a common post-mortem autopsy finding in patients who died from SUDEP, and therefore considered a pathological marker for SUDEP. Nevertheless, the degree of NPE in patients with epilepsy is often considered mild and not sufficiently severe to cause death. The objective of this systematic review is to study the epidemiology, seizure characteristics, clinical and radiographic presentation, as well as outcomes, and further assess its implication as a risk factor for SUDEP. Methods: A systematic review of the literature (1965-2017) was performed in electronic databases using a broad search strategy. Selected studies included English-language articles using the terms “neurogenic pulmonary edema” or “neurogenic pulmonary oedema” with “epilepsy” or “seizure”, seizure-associated pulmonary edema”, and “post-ictal pulmonary edema.” Studies were excluded if pulmonary edema occurred in the setting of left heart dysfunction or if there was an alternative etiology for the development of pulmonary edema. Two independent reviewers screened the abstracts, reviewed full articles, and performed data abstraction. Results: Thirty-three articles met inclusion criteria yielding a total of 45 cases (24 males, 21 females) of post-ictal NPE reported in the literature. The average age was 33.1 years (11 months to 69 years).  84.4% of patients had a known history of epilepsy, while 15.5% presented with new onset seizure. In those with a known history of epilepsy, 71% were on anti-epileptic drugs (AEDs) but data regarding seizure control was unavailable in most cases. All cases described had a generalized tonic-clonic seizure (GTCS) as the precipitating event. 39.5% of patients had a previous history of post-ictal NPE, while in 60.5% it was a first time event. Of those patients without previous history of post-ictal NPE two-thirds presented after a single GTCS, while the rest had more than one seizure prior to the event. A total of 6 patients died of SUDEP (13.3%) and all patients were younger than 45 years. Post-ictal NPE presented with dyspnea, hypoxia (SaO2 <90%) and fever in most cases; 11 patients had frank hemoptysis at presentation. Bilateral diffuse or patchy opacities were the most common findings on lung imaging. Symptomatic resolution occurred in <36 hrs in all surviving patients, but radiographic resolution was delayed up to 120 hrs after seizure onset. Despite the fact that all survivors had rapid resolution of symptoms, 9 patients required endotracheal intubation upon presentation. Conclusions: Post-ictal NPE occurs in young patients and exclusively after GTCS, sharing two major risk factors with SUDEP.  Although post-ictal NPE resolves rapidly in most cases, it carries a substantial mortality rate and can be an important risk factor for SUDEP. Funding: No funding was received.