A Descriptive Analysis of Prognostic Indicators in Patients with Non-Convulsive Status Epilepticus in a Tertiary Hospital Population

Background: Non-convulsive status epilepticus (NCSE) is defined as a change in mental state of at least 30 minutes associated with continuous or nearly continuous epileptiform discharges. Identification of prognostic indicators can guide decision making surrounding the use of poorly established treatment interventions in this heterogeneous population. Methods: We identified 66 consecutive inpatients with NCSE. Data surrounding clinical, electrographic, and treatment factors were collected via a retrospective systematic review of medical records and electronic EEGs, and were correlated with discharge outcome (return to baseline, new disability, or death). Results: Of all subjects, 21% returned to baseline, 26% acquired new disability, and 53% died, of whom half had anoxic encephalopathy. On univariate analysis, seventeen variables correlated significantly with death, although multivariate logistic regression analysis subsequently identified only comatose state and number of life threatening comorbidities as independent predictors of mortality. Of survivors, comatose state, critical care environment, length of hospital stay, and acute symptomatic seizures predicted new disability, with the latter two showing independent significance. Following exclusion of cases with anoxic encephalopathy, the use of an anaesthetic infusion was also an independent predictor of mortality. Conclusions: NCSE is associated with variable morbidity and mortality. While one fifth of our NCSE patients returned to baseline, those comatose with acute structural/metabolic seizures, anaesthetic infusions, and life threatening comorbidities were unlikely to survive without disability at discharge.

Can patients with non-convulsive seizure be identifi ed in the emergency department?

BACKGROUND: Non-convulsive seizure(NCS) is an underdiagnosed, potentially treatable emergency with significant mortality and morbidity. The objective of this study is to examine the characteristics of patients with NCS presenting with altered mental status(AMS) and diagnosed with electroencephalography(EEG), to identify the factors that could increase the pre-test probability of NCS.METHODS: Retrospective study using the data collected prospectively. Inclusion criteria: patients older than 13 years with AMS. Exclusion criteria:(1) immediately correctable AMS(e.g., hypoglycemia, opiod overdose);(2) inability to undergo EEG;(3) hemodynamic instability. Outcomes compared between NCS and non-NCS cases: vital signs, lactate level, gender, witnessed seizure, use of anticonvulsive in the field or in the ED, history of seizure or stroke, head injury, abnormal neurological finding and new abnormal findings on head CT. Data presented as medians and quartiles for categorical and percentages with 95%CI for continuous variables. Univariate analyses were performed with Man-Whitney U and Fisher's Exact tests. A multivariate analysis model was used to test the predictive value of clinical variables in identifying NCS.RESULTS: From 332 patients(median age 66 years, quartiles 50–78), 16 were diagnosed with NCS(5%, 95%CI 3%–8%). Only age was signifi cantly different between the NCS vs. non-NCS groups in both univariate(P=0.032) and multivariate analyses(P=0.016).CONCLUSION: Other than age, no other clinically useful variable could identify patients at high risk of NCS. ED physicians should have a high suspicion for NCS and should order EEG for these patients more liberally.

Non Convulsive Status Epilepticus: An Elusive Diagnosis

Absence status is the most common form of non-convulsive status epilepticus and is characterized by confusion with varying degrees of memory loss and cognitive impairment. Patients and Method: Three children were sent to neurological consultation due to behavioral alterations and a prolonged confused state;they were hospitalized and treated with sodium diphenylhydantoinate (DPH) IV at a dose of 10 mg/Kg. Results: The duration of symptoms varied from 6 months to 10 days. All three patients presented with global mental alterations, showing slowness in response and action. The electroencephalogram showed a pattern of slow, generalized stem and poly-stem-wavelengths of 3 - 4 Hz, which were registered for one hour. After the DPH bolus, the attack spontaneously ended in the 3 patients and upon examination all three presented with amnesia of the events occurring during the attack. In the follow-up, two of the patients did not experience further episodes and they showed normal scholastic achievement. The third patient however, after suffering a 6-month status epilepticus, failed the school year and finished his elementary education until the age of 15, experiencing similar difficulties with his secondary education. Discussion: Non-convulsive status epilepticus is more difficult to diagnose mainly because the manifestations are predominantly psychiatric and can be confused with other diseases or with an overdose of anti- convulsive drugs. A prolonged state of mental confusion, with no other explanation, should alert the attending physician to take an electroencephalogram in order to confirm the diagnosis. In our patients, DPH immediately controlled paroxysmal activity. We can therefore conclude that the problem is not in the treatment, but rather in making the correct diagnosis.

Continuous video electroencephalogram for herpes simplex encephalitis:a case report and literature review

Background:Electroencephalogram(EEG)is an important tool for the diagnosis of herpes simplex virus encephalitis(HSE).However,the diagnosis of non-convulsive status epilepticus(NCSE)in HSE is challenging without the help of continuous video EEG(CVEEG),and whether EEG is a predictor of outcome remains controversial.Case presentation:A 63-year-old woman presented with a 5 day history of fever,coma and seizures.Results of EEG,magnetic resonance imaging and polymerase chain reaction(PCR)in cerebrospinal fluid(CSF)were suggestive of herpes simplex encephalitis-1(HSE-1).Preliminary EEG showed periodic discharges at the prefrontal and temporal lobes,which were particularly synchronized with intermittent lip smacking movements,and the discharges were terminated by diazepam.After 2-week treatment with acyclovir,high-dose hormone pulse therapy and high-dose immunoglobulin therapy,the CSF was improved,but the patient’s consciousness became worsen,consistent with the diffuse slow waves in the delta range and low voltage of EEG activity.In the following 1 month,the patient had non-responsiveness to pain and sound as shown by CVEEG with diffuse slow waves.Sometimes paroxysmal very slow waves(0.5–1 Hz)were synchronized with intermittent paroxysmal eye movements,pupil abnormality,and sweating in the frontal area.After 2 months of treatment,the EEG abnormalities improved to have alpha rhythm.Conclusion:The CVEEG not only helps identify NCSE but can also be used to monitor HSE progression.