Estimating the economic burden of status epilepticus to the health care system.

PURPOSE: Status epilepticus (SE) is a major neurological condition associated with significant morbidity and mortality. No studies to evaluate the cost burden of SE have been performed to date. This study estimates the direct cost related to an inpatient admission for SE in an urban academic medical center. METHODS: Cases of SE were defined based on a standard 30 min or greater seizure duration. The inpatient claims data were analyzed for 192 patients admitted with SE from 1 July 1993 through 30 June 1994. Patient demographic and clinical characteristics associated with increased cost were identified using multiple regression. The direct costs for SE were compared with other common DRGs. RESULTS: The median reimbursement for a patient with SE was dollar 8417. The average length of stay for all SE patients was 12.9 days. Age groups (17-45 and 46-64) and etiology (acute CNS) were the only patient factors significantly associated with increased cost. SE patients had 30-60% higher reimbursements than patients admitted for other acute health problems including acute myocardial infarction or congestive heart failure. CONCLUSIONS: The direct inpatient costs for SE are high compared with the direct costs of admissions for other major conditions such as acute myocardial infarction or congestive heart failure. Data from this study were used to estimate a dollar 4 billion annual direct cost for inpatient admissions for SE. Given the incidence and the high costs, further more detailed evaluation of these costs may be useful in assessing the adequacy of reimbursement for this subset of patients with epilepsy.

The use of topiramate in refractory status epilepticus.

In cases of refractory status epilepticus (RSE) unresponsive to sequential trials of multiple agents, a suspension of topiramate administered via nasogastric tube was effective in aborting RSE, including one patient in a prolonged pentobarbital coma. Effective dosages ranged from 300 to 1,600 mg/d. Except for lethargy, no adverse events were reported.

Prevalence of nonconvulsive status epilepticus in comatose patients.

BACKGROUND: Nonconvulsive status epilepticus (NCSE) is a form of status epilepticus (SE) that is an often unrecognized cause of coma. OBJECTIVE: To evaluate the presence of NCSE in comatose patients with no clinical signs of seizure activity. METHODS: A total of 236 patients with coma and no overt clinical seizure activity were monitored with EEG as part of their coma evaluation. This study was conducted during our prospective evaluation of SE, where it has been validated that we identify over 95% of all SE cases at the Medical College of Virginia Hospitals. Only cases that were found to have no clinical signs of SE were included in this study. RESULTS: EEG demonstrated that 8% of these patients met the criteria for the diagnosis of NCSE. The study included an age range from 1 month to 87 years. CONCLUSION: This large-scale EEG evaluation of comatose patients without clinical signs of seizure activity found that NCSE is an underrecognized cause of coma, occurring in 8% of all comatose patients without signs of seizure activity. EEG should be included in the routine evaluation of comatose patients even if clinical seizure activity is not apparent.

Prospective population-based study of intermittent and continuous convulsive status epilepticus in Richmond, Virginia.

PURPOSE: Previous work suggested that there is a lower mortality for convulsive status epilepticus (SE) with intermittent seizures (intermittent SE) as opposed to SE with continuous seizure activity (continuous SE). A plausible hypothesis to explain this difference is that the shorter ictal time in intermittent SE is responsible for the lower mortality in this group. This study investigates the relative contributions of total ictal time and SE duration to the differing mortalities of intermittent and continuous SE. METHODS: Six hundred forty-five cases of prospectively identified convulsive SE were examined. Nonparametric statistical methods were used to compare continuous SE and intermittent SE variables. Multivariate logistic regression analyses were used to determine which factors were most highly associated with mortality. Intermittent SE cases were analyzed to evaluate the relative contributions of ictal time versus SE duration to mortality. RESULTS: Intermittent SE had a significantly lower mortality than continuous SE (19.6 vs. 31.4%; p < 0.001) in adults but not in children. Intermittent and continuous SE durations did not significantly differ in adult cases but did differ in pediatric cases. Ictal time was significantly shorter than SE duration for intermittent SE in both adults and children. After adjusting for age, etiology, and SE duration, SE type (continuous SE vs. intermittent SE) was shown to have an independent effect on mortality in adults. The relative risk of mortality for continuous SE was 1.79 times that of intermittent SE (p = 0.04). After controlling for SE duration, ictal time did not significantly affect mortality in adults. CONCLUSIONS: Intermittent and continuous convulsive SE were common in both pediatric and adult populations. Intermittent SE had a significantly lower mortality than did continuous SE. This difference in mortality was not completely explained by differences in SE duration, total ictal time, etiology, or age. Further research is needed to identify the factor(s) contributing to the significant difference in mortality between intermittent SE and continuous SE.

Comparison of status epilepticus with prolonged seizure episodes lasting from 10 to 29 minutes.

PURPOSE: Status epilepticus (SE) is a major medical and a neurologic emergency associated with significant morbidity and mortality. The current definition of SE is continuous seizure activity or intermittent seizure activity without regaining consciousness, lasting > or =30 min. Epilepsy monitoring unit data indicate that many seizures self-terminate within minutes. Thus consideration was recently given to include seizure episodes lasting > or =10 min in the definition of SE. Because no large studies have been conducted on seizures lasting 10-29 min, this study was initiated to compare cases of SE and 10 to 29-min seizure episodes seen within the same period. METHODS: Patients seen at the Medical College of Virginia Hospitals of Virginia Commonwealth University over the same 2-year period were studied. Two hundred twenty-six prospective SE cases (91 children and 135 adults) and 81 retrospective 10- to 29-min seizure episodes (31 children and 50 adults) were compared. A standardized data-entry-form system was compiled on each patient and was used to evaluate the data collected. RESULTS: The 10- to 29-min seizure patients and the SE cases had similar demographic characteristics, such as sex, race, and age, and also had similar etiologies. The majority (93%) of SE cases required anticonvulsant (AED) treatment to control and stop seizure activity. In the 10- to 29-min group, 43% stopped seizing spontaneously, and the remainder (57%) required AED treatment to stop seizure activity. The mortality for the SE patients was 19% compared with 2.6% for 10- to 29-min group (p<0.001). In the 10- to 29-min group that stopped seizing spontaneously, the mortality was 0. In the 10- to 29-min patients that required AED treatment, the mortality was 4.4%. CONCLUSIONS: The results demonstrate that a significant number of patients experience seizure activity lasting from 10- to 29-min. Approximately half of these seizure events stopped spontaneously and did not require AED treatment. The other half of the patients responded quickly to medications and stopped seizing before the 30-min definition for SE. The overall mortality of this group was significantly lower than that of the patients with SE. The results demonstrate that further studies on the 10- to 29-min seizure group are needed to differentiate seizures that will stop spontaneously and those that will only stop with AED treatment. Because almost half of the prolonged seizures stopped spontaneously, further studies are needed before including prolonged seizure activity in the definition of SE.