Occurrence of seizure clusters and status epilepticus during inpatient video-EEG monitoring.

OBJECTIVE: To investigate the occurrence of status epilepticus and seizure clusters, and the duration until first seizure at epilepsy monitoring units in the United States. METHODS: The authors examined the inpatient video-EEG monitoring reports of 514 consecutive patients admitted to five comprehensive epilepsy centers during the year 2000. Time to first seizure, seizure clustering, and seizure duration were ascertained from reports and entered into a database. RESULTS: In 169 admissions with complex partial seizures (CPSs) or secondarily generalized tonic-clonic (2GTC) seizures, there were 5 (3.0%) patients with status epilepticus, 30 (17.8%) with 4-hour seizure clusters, and 82 (48.5%) with 24-hour seizure clusters. There were no statistically significant differences between centers, except that seizure clusters were observed to be less common at the one center with a formal drug withdrawal protocol. The average time to CPS or 2GTC seizure was 2.1 days; the average number of days to nonepileptic event was 1.2 days (p = 0.001). CONCLUSIONS: Although status epilepticus is uncommon at epilepsy monitoring units, clusters of seizures are common. Intensive monitoring with drug withdrawal must be performed in a highly supervised, hospitalized setting. Inpatient video-EEG monitoring is efficient, with recording of the first epileptic or nonepileptic events in 2 days or less.

Elderly patients with systemic disease.

Although the healthy elderly seizure patient can often be treated with antiepileptic drugs (AEDs) similarly to a younger counterpart, the elderly with systemic disease require a more complex approach. The interplay of multiple organ dysfunctions and multiple non-AED medications greatly increases the challenges of managing the majority of older epilepsy patients. In addition, age-related physiologic changes in hepatic and renal function, volume of distribution, and exaggerated sensitivity to side effects alter the usual "rules" for administering AEDs. Thorough knowledge of the general principles of geriatric physiology and pharmacology may predict optimal selection of initial or subsequent AED therapy in this population.

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.

Epilepsy and seizure occurrence in a population-based sample of Virginian twins and their families.

Epilepsy and seizure occurrence was assessed in a large, population-based sample of Virginian twins and their families. Medical history information on twins and their relatives was collected by questionnaire and used to estimate prevalence of seizures and epilepsy for this sample. Health history information was available on 16,634 twins and their families. Lifetime prevalence of a history of seizures ranged from < 1 to 5%. Concordance rates were larger in monozygotic (MZ) than dizygotic (DZ) pairs overall, however, significant differences between the zygosities were only noted for Caucasian twins. To facilitate interpretation of results, the sample was partitioned into two age groups: 16-35 years and > 35 years of age. In the first age category of twins, significant differences were observed for the following seizure types; epilepsy (0.30 and 0.13, p <0.03), febrile seizures (0.39 and 0.12, p <0.001), and other convulsions/seizures (0.28 and 0.01, p < 0.001). While for twins in the second age category, only the comparison for febrile seizures (0.42 and 0.14, p < 0.001) resulted in a significant difference between zygosities. A family history of seizures was reported in 215 (35.1%) of the 613 seizure positive probands. Increased risk of seizures (1.88-4.64) among relatives of affected versus unaffected individuals was also observed.

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.

Persistent nonconvulsive status epilepticus after the control of convulsive status epilepticus.

PURPOSE: Convulsive status epilepticus (CSE) is a major medical and neurological emergency that is associated with significant morbidity and mortality. Despite this high morbidity and mortality, most acute care facilities in the United States cannot evaluate patients with EEG monitoring during or immediately after SE. The present study was initiated to determine whether control of CSE by standard treatment protocols was sufficient to terminate electrographic seizures. METHODS: One hundred sixty-four prospective patients were evaluated at the Medical College of Virginia/VCU Status Epilepticus Program. Continuous EEG monitoring was performed for a minimum of 24 h after clinical control of CSE. SE and seizure types were defined as described previously. A standardized data form entry system was compiled for each patient and used to evaluate the data collected. RESULTS: After CSE was controlled, continuous EEG monitoring demonstrated that 52% of the patients had no after-SE ictal discharges (ASIDS) and manifested EEG patterns of generalized slowing, attenuation, periodic lateralizing epileptiform discharges (PLEDS), focal slowing, and/or burst suppression. The remaining 48% demonstrated persistent electrographic seizures. More than 14% of the patients manifested nonconvulsive SE (NCSE) predominantly of the complex partial NCSE seizure (CPS) type (2). These patients were comatose and showed no overt clinical signs of convulsive activity. Clinical detection of NCSE in these patients would not have been possible with routine neurological evaluations without use of EEG monitoring. The clinical presentation, mortality, morbidity, and demographic information on this population are reported. CONCLUSIONS: Our results demonstrate that EEG monitoring after treatment of CSE is essential to recognition of persistent electrographic seizures and NCSE unresponsive to routine therapeutic management of CSE. These findings also suggest that EEG monitoring immediately after control of CSE is an important diagnostic test to guide treatment plans and to evaluate prognosis in the management of SE.

Hemodynamic monitoring prior to and at the time of death in status epilepticus.

Status epilepticus (SE) is a common neurological and medical emergency. Despite the significant mortality associated with SE, no human data have been available regarding cardiovascular changes prior to death in patients with this condition. This study was conducted to measure hemodynamic trends in the 24 h prior to death in a series of 24 prospectively evaluated SE patients. Two distinct cardiovascular patterns of mean arterial pressure (MAP) and heart rate (HR) were observed. Ten patients had a gradual decline in MAP and/or HR, and this group was designated as having gradual cardiac decompensation (GCD). The remaining 14 patients showed no significant changes in either MAP or HR up to the time of death. This group of patients was designated as having acute cardiac decompensation (ACD). The changes in MAP and HR over the last 24 h prior to death between the GCD and ACD groups were statistically significant. Ninety percent of the GCD patients had a history of multiple risk factors for arteriosclerotic cardiovascular disease (ASCVD), while only 30% of the ACD group had a history of multiple risk factors for ASCVD. The results provide the first human data of cardiovascular events immediately preceding death in SE patients. We propose that further investigation of the cardiovascular pathophysiology of SE may provide new therapeutic interventions which could decrease the significant mortality associated with SE.

Synergistic effect of status epilepticus and ischemic brain injury on mortality.

Ischemic brain injury (stroke) is a major cause of status epilepticus (SE). In our database of 529 adult SE cases, acute or remote cerebrovascular accidents (CVA) were a primary cause of SE for 41% of the patients overall and for 61% of the elderly patients. SE in the setting of acute CVA has a very high mortality, approaching 35%. The degree to which mortality can be attributed to the severity of the underlying CVA etiology vs. the effect of SE has not been evaluated. To address this issue, we prospectively studied patients with SE and acute CVA and compared them to control populations with acute CVA alone or with SE and remote CVA. The groups did not significantly differ with regard to age, sex, or radiographic lesion size. Mortality was unrelated to lesion size in the CVA and SE group. Overall, acute CVA and SE patients had an almost three-fold increase in mortality compared to the CVA group and an eight-fold increase compared to the SE and the non acute (remote) CVA group. Logistic regression analysis demonstrated a statistically significant synergistic effect of SE and CVA on mortality. This is the first study to document that the high mortality of SE and acute CVA is not solely due to the severity of the underlying CVA etiology, but due to the synergistic effect of combined injuries from SE and cerebral vascular ischemia.

Evidence for a genetic predisposition for status epilepticus.

The role of genetic factors in determining risk for status epilepticus (SE) was examined in twins identified using the population-based Virginia Twin Registry. Concordance rates for SE were 0.38 for monozygotic (MZ) and 0.00 for dizygotic (DZ) twins, with the rate in MZs being significantly increased over DZs. The prevalence of SE in MZ co-twins of affected individuals was as high as 0.55. Clinical presentation of SE was evaluated, and no association was found between occurrence of SE and age at onset or seizure etiology. Genetic factors contribute to risk for SE.

Seizures in medically complex patients.

Seizures are not an uncommon complication of medical conditions and should not be ascribed simply to "multifactorial" causes. Although many interacting factors may contribute to a lowered threshold for seizures, a careful systems-oriented search usually yields specific factors that are of primary importance. Not all medically complex patients with seizures have persistent or irreversible processes that lead to recurrent seizures or a need for maintenance antiepileptic drugs (AEDs). Because AEDs contribute to the potential for drug interactions, side effects, and toxicities in situations already encumbered with significant polypharmacy, the decision not to initiate such therapy can be even more important than selecting the best agent, best route of administration, and best dose from a growing list of AEDs.

A prospective, population-based epidemiologic study of status epilepticus in Richmond, Virginia.

This report presents the initial analysis of a prospective, population-based study of status epilepticus (SE) in the city of Richmond, Virginia. The incidence of SE was 41 patients per year per 100,000 population. The frequency of total SE episodes was 50 per year per 100,000 population. The mortality rate for the population was 22%, 3% for children and 26% for adults. Evaluation of the seizure types for adult and pediatric patients demonstrated that both partial and generalized SE occur with a high frequency in these populations. Based on the incidence of SE actually determined in Richmond, Virginia, we project 126,000 to 195,000 SE events with 22,200 to 42,000 deaths per year in the United States. The majority of SE patients had no history of epilepsy. These results indicate that SE is a common neurologic emergency.

Epidemiology of status epilepticus.

This study presents a review of the epidemiology of status epilepticus (SE) in Richmond, Virginia, U.S.A. The data summarize some of the first population-based information on the natural presentation of SE in a controlled community setting. SE occurred with an absolute incidence rate of 41 patients per 100,000 residents per year in Richmond. The frequency of total SE occurrences was 50 patients per 100,000 residents per year. Overall mortality in this population was 22%. Absolute incidence and occurrences of SE in this population were shown to be underestimates due to the inability, for multiple reasons, to document all cases of SE. Based on the Richmond data, the number of SE cases, frequencies of occurrence, and deaths per year occurring in the United States were estimated to be 102,000-152,000, 125,000-195,000, and 22,000-42,000, respectively. In Richmond, nonwhites had a much higher incidence of SE than did whites. Partial SE was the most common form of seizure initiating SE. Age and etiology were also found to contribute to mortality. Infants <1 year of age had the highest incidence of SE, but the elderly population represented the largest number of SE cases. This study provides a review of the first prospective, population-based, epidemiological data on SE and shows that SE is a major medical and neurological emergency in both academic and community hospital settings.

Safety and efficacy of rectal prochlorperazine for the treatment of migraine in the emergency department.

STUDY OBJECTIVE: To assess the safety and efficacy of rectal prochlorperazine in the treatment of acute migraines. DESIGN: Randomized, double-blinded, placebo-controlled study. SETTING: Emergency department of an inner-city university hospital. PARTICIPANTS: ED patients with documented diagnosis of migraines. INTERVENTIONS: Vital signs and level of alertness were monitored immediately before drug administration and 120 minutes after dosing. Pain intensity and adverse events were monitored immediately before drug administration and at 30, 60, and 120 minutes after dosing. RESULTS: A positive outcome was defined as a pain score less than or equal to 5 on a 10-point scale or a 50% reduction in pain intensity from baseline at 120 minutes after dosing. All patients treated with prochlorperazine suppositories experienced a positive treatment outcome; only 50% of patients treated with placebo experienced a positive result at 120 minutes after dosing (P = .016). Pain intensity scores were significantly lower in the prochlorperazine group at 120 minutes (P = .018). There were no adverse reactions in either group, and there were no significant differences in vital signs or levels of alertness between groups. Patients who failed therapy were given rescue medication 120 minutes after dosing. CONCLUSION: Prochlorperazine administered as a 25-mg rectal suppository provides excellent pain relief within 2 hours in patients with acute migraines.

Analysis of electrocardiographic changes in status epilepticus.

The high mortality associated with status epilepticus (SE) has been hypothesized to result partially from neurologically induced changes in cardiac function. To test this hypothesis, we reviewed electrocardiograms of 60 patients presenting in status epilepticus. Sequential electrocardiograms before, during and after ictal episodes were compared to define changes from baseline studies. 58.3% of the SE patients (N = 35) exhibited significant abnormalities on electrocardiograms obtained within 24 h of status epilepticus. Specific electrocardiographic changes included arrhythmias, axis changes, conduction abnormalities and ischemic patterns. All of these abnormal ECG changes met generally accepted cardiologic standards for a high risk of myocardial dysfunction or ischemia. The association of ECG changes with mortality was statistically significant. These results indicate that a significant proportion of SE patients are at risk for cardiac dysfunction and that close monitoring of cardiac function is indicated during and after SE.