Predictive value of the Status Epilepticus Severity Score (STESS) and its components for long-term survival

Abstract

BackgroundThe “Status Epilepticus Severity Score” (STESS) is the most important clinical score to predict in-hospital mortality of patients with status epilepticus (SE), but its prognostic relevance for long-term survival is unknown. This study therefore examined if STESS and its components retain their prognostic relevance beyond acute treatment.MethodsOne hundred twenty-five non-anoxic patients with SE were retrospectively identified in two hospitals between 2008 and 2014 (39.2 % refractory SE). Patients’ treatment, demographic data, date of death, aetiology of SE, and the components of the STESS (age, history of seizures, level of consciousness and worst seizure type) were determined based on the patients’ records.ResultsIn 94.4 % of patients, SE was treated successfully; in-hospital mortality rate was 12 %. The overall mortality was 42 % after median follow-up of 28.1 months. The survival plateaued after about 3 years, all patients with progressive brain diseases (n = 4) died within one year. In-hospital mortality correlated highly significantly with STESS, the optimal cut-off was 4. With respect to long-term outcome, STESS correlated significantly with overall mortality though with lower odds ratios. When looking only at patients that survived the acute phase of treatment, only the STESS components “level of consciousness” (at admission), “coma” as worst seizure type, and “age” reached a statistical significant association with mortality. In these patients, STESS with a cut-off of 4 was not significantly associated with survival/mortality. Aetiology of SE was insufficient to explain the weak association and the high mortality after discharge alone.ConclusionSTESS at onset of SE reliably assessed in-hospital mortality, and was indicative for overall survival. However, STESS did not allow correct estimation of mortality after discharge. The high mortality after discharge and high overall mortality of patients diagnosed with SE was not explained by progressive brain disorders alone. Further research is needed to understand the causes for high overall mortality after SE and putative prognostic factors.Electronic supplementary materialThe online version of this article (doi:10.1186/s12883-016-0730-0) contains supplementary material, which is available to authorized users.

Factors associated with refractoriness and outcome in an adult status epilepticus cohort

“…Interestingly, both new scoring systems STESS and EMSE-EACE that have been designed to predict SE mortality were indeed found to be associated with outcome in the univariate analysis of our study. Several previous studies have found a significant association between STESS and outcome [7,19]. Only a few studies have evaluated both STESS and EMSE, and have found, as in our study, a stronger association for EMSE-EACE than for STESS [21,41].…”

“…Moreover, the factors that lead to refractoriness and that determine outcome in SE are still insufficiently elucidated. Two new clinical scoring systems have emerged for the prediction of mortality in SE, Status Epilepticus Severity Score (STESS) [15,16] and Epidemiology based Mortality score in SE (EMSE) [17], but studies have shown that they are better at predicting survival than death, with high negative predictive values and low positive predictive values [15,[17][18][19][20]. No such validated scoring systems currently exist for the prediction of refractoriness, and various factors like low level of consciousness before treatment, acute symptomatic etiologies, age, non-convulsive SE in coma, absence of previous seizures, low levels of serum albumin at SE onset and periodic discharges on EEG have been found to be associated with refractoriness in different studies [4][5][6][7]21].…”

Long‐term outcomes of status epilepticus: A critical assessment

“…Risk factors for mortality in adults include etiology (progressive, remote, or acute symptomatic causes),8, 12, 13, 24, 55 older age,11, 12 SE duration,8, 13, 56 and development of subsequent epilepsy 11. The Status Epilepticus Severity Score is a valuable tool to assess in‐hospital mortality but has not been clearly validated to estimate long‐term mortality 57, 58, 59. The Epidemiology‐Based Mortality in Status Epilepticus score considers etiology, age, electroencephalogram, and comorbidities and has been associated with poor long‐term outcome in one prospective study 19…”

“…11 The Status Epilepticus Severity Score is a valuable tool to assess in-hospital mortality but has not been clearly validated to estimate long-term mortality. [57][58][59] The Epidemiology-Based Mortality in Status Epilepticus score considers etiology, age, electroencephalogram, and comorbidities and has been associated with poor long-term outcome in one prospective study. 19…”

Prognostic scores in status epilepticus—a critical appraisal

“…Among 468 retrieved studies, ten studies on the development or validation of prognostic scales in SE were included after screening titles and abstracts (Figure 1). [6][7][8][9][10][11][12][13][14][15] A total of 4 prognostic scores have been proposed to date: the Status Epilepticus Severity Score (STESS), 6,7 the Epidemiology-based Mortality score in Status Epilepticus (EMSE), 8 the modified STESS (mSTESS), 9 and the Encephalitis Nonconvulsive Status Epilepticus Diazepam Resistence Imaging Tracheal Intubation (END-IT) score, 10 the latter of which was developed by our group.…”