Continuous Epileptiform Discharges Research Articles

Continuous epileptiform discharges are associated with worse neurodevelopmental findings in a congenital Zika syndrome prospective cohort

PurposeThis study aimed to identify continuous epileptiform discharges (CEDs) on electroencephalograms (EEG) and to determine their clinical significance in children with congenital Zika syndrome (CZS). MethodsThis prospective cohort study included 75 children diagnosed with CZS born from March 2015 and followed up until September 2018 (age up to 36 months). EEG was performed to detect CEDs up to 24 months old. Data on obstetric, demographic, and clinical signs; cranial computed tomography (CT); ophthalmology examination; anti-seizure medication; growth; and motor development were collected. Fisher's exact test was used to verify the associations between categorical variables, and the T- test was used to compare the mean z-scores of anthropometric measurements between the groups with and without CED. ResultsCEDs were identified in 41 (54.67 %) children. The mean age of CEDs identification was 12.24 ± 6.86 months. Bilateral CEDs were shown in 62.89 % of EEGs. CEDs were associated with severe congenital microcephaly, defined by z-score >3 standard deviation of head circumference (HC) below the mean for sex and age (p = 0.025), and worse outcomes, including first seizure before 6 months (p = 0.004), drug-resistant epilepsy (p < 0.001), chorioretinal scarring or mottling (p = 0.002), and severe CT findings (p = 0.002). The CED group had lower mean z-scores of HC up to 24 months of age. ConclusionThis is the first description of the prevalence and significance of CEDs that also remains during wakefulness in patients with CZS. New investigations may suggest that it is more appropriate to classify the EEG not as a CED, but as a periodic pattern. Anyway, CEDs may be a marker of neurological severity in children with CSZ.

An attention-based deep learning method for the detection of electrical status epilepticus during sleep from electroencephalogram waveform analysis in children

Electrical status epilepticus during sleep (ESES) is a special interictal electroencephalographic phenomenon observed in children with epilepsy. ESES refers to continuous or nearly continuous epileptiform discharges of bilateral (or unilateral) spikes and waves induced during non-rapid eye movement (NREM) sleep. It mainly manifests in a series of childhood epileptic syndromes characterized by seizures, ESES, and cognitive impairment, which seriously affect the health of children. Typically, the spike-wave index (SWI), which is the percentage of spikes and waves duration in the total NREM time, is an important criterion for diagnosing ESES. The SWI measures the proportion of the total duration of spikes and waves to the NREM sleep time within several hours. Currently, SWI is obtained primarily by manual measurement and calculation, which has a certain subjective bias, low accuracy, time and labor consumption, and is a waste of medical resources. Therefore, we designed a novel data segmentation model based on a multiresolution convolutional neural network and a self-attention mechanism to calculate the SWI quickly and accurately. This can assist clinicians in making more accurate judgments and providing a better guide for the treatment of children with epilepsy. A large amount of clinical patient data was used to test the proposed model. The results confirmed that this model has an acceptable generalization ability for data from different patients and the same patient at different times. Each performance index of the model was superior to that of current common models, thus fulfilling the requirements for clinical testing.

Interictal pattern on scalp electroencephalogram predicts excellent surgical outcome of epilepsy caused by focal cortical dysplasia.

ObjectiveFocal cortical dysplasia (FCD) represents an essential cause of drug‐resistant epilepsy with surgery as an effective treatment option. This study aimed to identify the important predictors of favorable surgical outcomes and the impact of the interictal scalp electroencephalogram (EEG) patterns in predicting postsurgical seizure outcomes.MethodsWe retrospectively evaluated 210 consecutive patients between 2015 and 2019. They were diagnosed with FCD by pathology, underwent resection, and had at least one year of postsurgical follow‐up. Predictors of seizure freedom were analyzed.ResultsBased on the information at the latest follow‐up, seizure outcome was classified as Engel Class I (seizure‐free) in 81.4% and Engel Class II‐IV (non‐seizure‐free) in 18.6% of patients. There were 43, 105, and 62 cases of FCD type I, type II, and type III, respectively. The interictal EEG showed a repetitive discharge pattern (REDP) in 87 (41.4%) patients, polyspike discharge pattern (PDP) in 41 (19.5%), and the coexistence of REDP and PDP in the same location in 32 (15.2%) patients. The analyzed patterns in order of frequency were repetitive discharges lasting 5 seconds or more (32.4%); polyspikes (16.7%); RED type 1 (11.4%); continuous epileptiform discharges occupying >80% of the recording (11.4%); RED type 2 (6.2%); brushes (3.3%); focal, fast, continuous spikes (2.4%); focal fast rhythmic epileptiform discharges (1.43%); and frequent rhythmic bursting epileptiform activity (1.4%). The coexistence of REDP and PDP in the same location on scalp EEG and complete resection of the assumed epileptogenic zone (EZ) was independently associated with favorable postsurgical prognosis.SignificanceResective epilepsy surgery for intractable epilepsy caused by FCD has favorable outcomes. Interictal scalp EEG patterns were revealed to be predictive of excellent surgical outcomes and may help clinical decision‐making and enable better presurgical evaluation.

Pericardial Injection of Kainic Acid Induces a Chronic Epileptic State in Larval Zebrafish.

Epilepsy is a common disorder of the brain characterized by spontaneous recurrent seizures, which develop gradually during a process called epileptogenesis. The mechanistic processes underlying the changes of brain tissue and networks toward increased seizure susceptibility are not fully understood. In rodents, injection of kainic acid (KA) ultimately leads to the development of spontaneous epileptic seizures, reflecting similar neuropathological characteristics as seen in patients with temporal lobe epilepsy (TLE). Although this model has significantly contributed to increased knowledge of epileptogenesis, it is technically demanding, costly to operate and hence not suitable for high-throughput screening of anti-epileptic drugs (AEDs). Zebrafish, a vertebrate with complementary advantages to rodents, is an established animal model for epilepsy research. Here, we generated a novel KA-induced epilepsy model in zebrafish larvae that we functionally and pharmacologically validated. KA was administered by pericardial injection at an early zebrafish larval stage. The epileptic phenotype induced was examined by quantification of seizure-like behavior using automated video recording, and of epileptiform brain activity measured via local field potential (LFP) recordings. We also assessed GFP-labeled GABAergic and RFP-labeled glutamatergic neurons in double transgenic KA-injected zebrafish larvae, and examined the GABA and glutamate levels in the larval heads by liquid chromatography with tandem mass spectrometry detection (LC-MS/MS). Finally, KA-injected larvae were exposed to five commonly used AEDs by immersion for pharmacological characterization of the model. Shortly after injection, KA induced a massive damage and inflammation in the zebrafish brain and seizure-like locomotor behavior. An abnormal reorganization of brain circuits was observed, a decrease in both GABAergic and glutamatergic neuronal population and their associated neurotransmitters. Importantly, these changes were accompanied by spontaneous and continuous epileptiform brain discharges starting after a short latency period, as seen in KA rodent models and reminiscent of human pathology. Three out of five AEDs tested rescued LFP abnormalities but did not affect the seizure-like behavior. Taken together, for the first time we describe a chemically-induced larval zebrafish epilepsy model offering unique insights into studying epileptogenic processes in vivo and suitable for high-throughput AED screening purposes and rapid genetic investigations.

Cortical and thalamic hyper-perfusion in non-convulsive status epilepticus. Relationship between perfusion CT patterns and Salzburg EEG criteria

IntroductionStatus epilepticus (SE) is a neurological emergency and in particular nonconvulsive SE (NCSE) represents a diagnostic challenge. To improve clinical decision-making, cerebral perfusion-computed tomography (PCT) has been shown as a helpful tool to support the diagnosis of focal NCSE. Materials and methodsThis is a monocentric retrospective study. Among the 602 cases of SE observed between September 2013 and April 2020 we included 21 patients that were studied with PCT. The perfusion maps were first visually analysed then a quantitative analysis (by regions of interest, ROI) was obtained. For each patient, the diagnostic EEG was reviewed and classified in accordance to the Salzburg Criteria for NCSE (SCC) as definite (D-NCSE) and possible (P-NCSE). Finally, we analysed the relationship between PCT and EEG patterns. ResultsHyper-perfusion was observed in 18 patients (86%), while in the remaining 3 (14%) a normo-perfused pattern was present. Hyper-perfusion was observed in 14 of the D-NCSE group (88%) and in the two patients with a P-NCSE (100%). No one among the patients with a P-NCSE had a thalamic hyper-perfusion, while among the 6 patients with continuous sustained epileptiform discharges > 2.5 Hz (pattern 1 of SCC), 4 (67%) showed cortical plus thalamic hyper-perfusion. ConclusionsPCT could facilitate the differential diagnosis and speed-up the diagnostic process of NCSE in emergency situations. Finding cortical multi-lobar hyper-perfusion, especially if present together with homolateral thalamic hyper-perfusion in a patient with an acute-onset of motor/sensory/language deficits is highly suggestive for the presence of NCSE and is particularly related to continuous/sustained ictal patterns.

Mecamylamine modulates epileptiform discharges in low-Mg2+ model of epilepsy

Mecamylamine is a nonselective antagonist of nicotinic acetylcholine receptors that was developed as an antihypertensive medication and is now being studied for its beneficial effects in several pathological conditions, such as substance abuse, depression, anxiety and epilepsy. In this work, we investigate the effect of mecamylamine on the manifestations of seizure-like activity evoked by perfusion of hippocampal slices with low-Mg2+ solution of artificial cerebrospinal fluid. Reducing Mg2+ concentration in extracellular solution induced two distinct types of epileptiform activity: recurring seizure-like activity and continuous discharges. Application of mecamylamine significantly increased internal frequency of recurring seizurelike activity and significantly decreased inter-event intervals between continuous discharges. We also show that mecamylamine significantly decreased internal frequency of continuous epileptiform discharges. The results of our work show that mecamylamine exerts modulatory effect on the low-Mg2+ epileptiform activity induced in hippocampal acute rat brain slices. Additionally, obtained results indicate the role of nicotinic acetylcholine receptors in the modulation of hippocampal network activity, which might explain some of the therapeutic effects of mecamylamine in CNS.

Continuous epileptiform discharges during sleep as an evolutionary pattern in patients with congenital Zika virus syndrome.

Congenital Zika virus syndrome (CZVS) is associated with severe neurological deficits. Clinical characteristics of epilepsy and the electroencephalographic (EEG) pattern in CZVS were documented in infancy. In this study, we aimed to describe the EEG findings observed during the follow-up of children with CZVS. Seventy-six EEGs of 55 children (60% female; mean age = 50months) with confirmed CZVS were analyzed, considering the background, interictal, and ictal epileptiform discharges. Continuous (or almost continuous) epileptiform discharges during non-rapid eye movement sleep were identified in 22 (40%) patients. In 20 (90.1%) patients, the pattern was symmetrical, with an anterior predominance of the epileptiform activity. All patients with this pattern had epilepsy, which was severe in 15 (68.2%) and demanded polytherapy in 19 (86.4%). Subcortical calcifications (77.3%) and multifocal EEGs (72.8%) in earlier ages occurred more often in patients with this pattern. Other unspecific interictal EEG patterns were focal epileptiform discharges in 23 (41.8%) and multifocal activity in six (10.9%). In CZVS, continuous (or almost continuous) epileptiform discharges during sleep emerge as a pattern after the second year of life. This was associated with severe and drug-resistant epilepsy, but not necessarily with an apparent regression. Subcortical calcifications and multifocal epileptiform discharges in infancy are associated with this pattern.

P02-T Clinical outcome and EEG patterns in superrefractory-nonconvulsive status epilepticus- single centre experience

Background Nonconvulsive status epilepticus (NCSE) is a life threatening condition with very high mortality rate. The diagnosis is mainly based on electroencephalograpy (EEG). The aim was to study the EEG findings and epidemiology of superrefractory NCSE (SR-NCSE) in our center. Material and methods A retrospective database was compiled from patient files between 2013 and 2018. From 150 status epilepticus patients 13 were found to have SR-NCSE. EEG was evaluated ac-cording to the Salzburg Consensus Criteria. The following parameters were collected: status epilepticus severity score (STESS) and epidemiology-based mortality score in status epilepticus (EMSE), time until the diagnosis and clinical outcome. Results From the SE patients 8.6% had SR- NCSE, 77% of them female. The average age was 71.4 ± 21 years ( 90 30%.) The average time until the first EEG was 15.49 h, at the time of the diagnosis already in superrefractory stage. The mortality rate was very high (77%). The survivors had good outcome, modified Rankin scale 0–1. STESS and EMSE scores gave a good prediction of out-come. The 4 patients with burst-suppression pattern on EEG all died. The others had continuous epi-leptiform discharges (EDs, spikes and sharp waves). All who survived were alert or somnolent, and had an acute treatable aetiology. Only one patient had epileptic seizures previously and recovered. Conclusion Most NCSE cases stay hidden, or are diagnosed already in a refractory stage. Using STESS and EMSE scores helps to predict the outcome. Surveillance and education may improve the outcome and diagnosis of NCSE.

Scalp electroencephalographic biomarkers in epilepsy patients with focal cortical dysplasia

To assess scalp electroencephalographic (EEG) patterns as possible biomarkers for an underlying focal cortical dysplasia (FCD) in patients with structural epilepsy. Scalp electroencephalograms (EEGs) of epilepsy patients with histologically confirmed diagnosis of FCD type I or II (n = 71, age = 3-66 years, 28 female) and of controls with other underlying pathologies (n = 43, age = 2-60 years, 16 female) were retrospectively evaluated regarding the presence or absence of 12 scalp EEG patterns previously reported to be associated with FCD. Furthermore, 2 subgroups of these biomarkers with common characteristics were also analyzed. Each of the 12 biomarkers was tested for association with FCD by comparing the presence of each feature in FCD patients and controls using Fisher exact test. A significant association with FCD as underlying etiology was found for 6 of 12 previously reported biomarkers. With decreasing odds ratios, these were continuous epileptiform discharges, 2 types of rhythmic epileptiform discharges, polyspikes, frequent rhythmic bursting epileptiform activity, and repetitive discharges as well as the subgroups containing repetitive activity and polyspikes, respectively. Presence of EEG biomarkers was independent of a visible underlying magnetic resonance imaging-visible lesion, and had similar prevalence with FCD I and II. Individual biomarkers had specificities of 65 to 98% and sensitivities of 17 to 61% for an underlying FCD, and combinations of EEG biomarkers achieved 100% specificity. This study confirms that there are several surface EEG biomarkers significantly associated with an underlying cortical dysplasia. These biomarkers may aid in localizing suspicious brain regions and provide evidence for dysplastic brain tissue also in nonlesional patients of either histological FCD subtype. Ann Neurol 2018;84:564-575.

Intraoperative fast ripples independently predict postsurgical epilepsy outcome: Comparison with other electrocorticographic phenomena

In the surgical management of epilepsy, the resection of cortex exhibiting interictal fast ripples (250–500Hz) on electrocorticography has been linked to postoperative seizure-freedom. Although fast ripples appear to accurately identify the epileptogenic zone—the minimum tissue that must be removed at surgery to achieve seizure-freedom—it has not been established that fast ripples are a superior biomarker in comparison with multimodal presurgical neuroimaging and other electrocorticography abnormalities. Hence, in the prediction of postoperative seizure-freedom, we compared the value of fast ripples with other intraoperative electocorticography abnormalities including focal slowing, paroxysmal fast activity, intermittent spike discharges, continuous epileptiform discharges, focal attenuation, and intraoperative seizures, as well as complete resection of the lesion defined by MRI and other neuroimaging. In a cohort of 60 children with lesional epilepsy and median postsurgical follow-up exceeding 4 years, who underwent resective epilepsy surgery with intraoperative electrocorticography, we evaluated the extent to which removal of each intraoperative electrocorticography abnormality impacts time to first postoperative seizure using the Kaplan-Meier method and Cox proportional hazards regression. Secondly, we contrasted the predictive value of resection of each competing electrocorticography abnormality using standard test metrics (sensitivity, specificity, positive predictive value, and negative predictive value). In contrast with all other intraoperative electrocorticography abnormalities, fast ripples demonstrated the most favorable combination of positive predictive value (100%) and negative predictive value (76%) in the prediction of postoperative seizures. Among all candidate electrocorticography features, time to first postoperative seizure was most strongly associated with incomplete resection of fast ripples (hazard ratio=19.8, p<0.001). In multivariate survival analyses, postoperative seizures were independently predicted by incomplete resection of cortex generating fast ripples (hazard ratio=25.4, 95%CI 6.71–96.0, p<0.001) and focal slowing (hazard ratio=5.79, 95%CI 1.76–19.0, p=0.004), even after adjustment for the impact of an otherwise complete resection. All children with incomplete resection of interictal FR-generating cortex exhibited postoperative seizures within six months. Notably, this cohort included many patients with large resections and thus limited opportunity to exhibit unresected fast ripples. Future study in a cohort with small resection volume, or a clinical trial in which resection margins are guided by fast ripple distribution, would likely yield a more precise estimate of the risk posed by unresected fast ripples. With a high detection rate during brief intraoperative electrocorticography and favorable positive and negative predictive value, interictal fast ripple characterization during surgery is a feasible and useful adjunct to standard methods for epilepsy surgery planning, and represents a valuable spatially-localizing biomarker of the epileptogenic zone, without the need for prolonged extraoperative electrocorticography.

ID 337 – Response to clonazepam in typical absence status epilepticus

Objective Absence status epilepticus ASE is a type of non convulsive status epilepticus in which continuous or recurrent generalised epileptiform discharges are associated with a varying grade of consciousness.We describe the case of an elderly man who presented with typical ASE resolved after intravenous clonazepam. Methods Clinical case report. Results A 62-year old man had a history of idiopathic generalised epilepsy with tonic-clonic seizures.Treated since the age of 30 years with phenobarbital PB 100 mg/day.He was disoriented to time and place and a slowness in mental activity over 24 h after food poisoning. Laboratory tests and a CT scan of the brain were normal.brain MRI did not show any structural lesions.EEG showed recurrent generalsed paroxysms of 3 Hz spike-wave.Normal background activity.Normalisation of mental status and EEG pattern after 1mg intravenous clonazepam (Benzodiazepine). Phenobarbital PB was substituted by valproic acid 1500 mg/day. Conclusion Typical ASE diagnosis must be based on EEG pattern and clinical history. Efficacy of intravenous clonazepam in treatment of typical ASE.

PET hypermetabolism in medically resistant childhood epilepsy: Incidence, associations, and surgical outcome.

We observed several children with medically resistant epilepsy demonstrating focal positron emission tomography (PET) hypermetabolism, a finding rarely reported and of questionable significance. We therefore retrospectively reviewed the incidence of hypermetabolic PET, and its relationship to electroencephalography (EEG) and magnetic resonance imaging (MRI) findings, and to the outcome of epilepsy surgery. We retrospectively reviewed 498 PET brain studies in patients with medically resistant childhood epilepsy for evidence of hypermetabolism. In patients with PET hypermetabolism, we correlated metabolic abnormality with the scalp EEG and MRI findings. In a subset of patients who underwent surgical resection, we further correlated the PET findings with histopathologic and surgical outcomes. Focal PET hypermetabolism was identified in 33 (6.6%) of 498 studies. The region of hypermetabolism correlated with a spike count of ≥10 per minute in 26 of 32 concomitant scalp EEG studies and 18 of 21 lesions evident on MRI. In 17 patients who underwent surgical resection, PET hypermetabolism further correlated with regions revealing almost continuous epileptiform discharges on the intracranial EEG and with histopathologically malformative tissue. At a minimum follow-up of 1 year postsurgery (median 33 months), 7 (50%) of 14 patients had Engel's class I outcome, 4 patients had class II, and 2 had class III outcome, whereas one patient was unchanged. At last follow-up, seizure freedom was noted in five of seven patients with focal PET hypermetabolism alone versus three of eight patients with PET hypometabolism. Focal PET hypermetabolism is associated with high spike frequency on scalp EEG and can occur in the absence of ictal events during the peri-injection period. Correlation with intracranial EEG usually corroborates the highly epileptogenic pathophysiologic state. Cortical malformations constitute the most common pathologic substrate, and resection of the hypermetabolic PET region may facilitate favorable outcomes. These observations indicate that focal PET hypermetabolism is an important marker of the epileptogenic zone and may represent its epicenter.

A Comatose Patient with Continuous Generalized 3 Hz Spike-and-Wave Discharges after Cardiac Arrest

The electroencephalogram exhibits continuous epileptiform discharges in many advanced coma stages, described as comatose nonconvulsive status epilepticus (NCSE). Comatose NCSE might represent an irreversible brain damage, but its causal role remains unclear. We experienced a comatose patient with continuous generalized 3 Hz spike-and-wave discharges after cerebral anoxia, which is a quiet similar electroencephalographic pattern of typical absence status epilepticus. This case indicates that NCSE in comatose patients may be overdiagnosed if the diagnosis is based on electroencephalographic alterations alone. Key Words: Nonconvulsive status epilepticus, Absence status epilepticus, Coma

WORK, REST AND PLAY; THE CLINICAL SPECTRUM OF NON–CONVULSIVE STATUS EPILEPTICUS

IntroductionNon–convulsive status epilepticus (NCSE) is defined as prolonged seizure activity in the absence of motor features or a change in behaviour and/or mental processes from baseline associated with continuous epileptiform...

Reproducibility of EEG–fMRI Results in a Patient With Fixation-Off Sensitivity

Blood oxygenation level-dependent (BOLD) activation associated with interictal epileptiform discharges in a patient with fixation-off sensitivity (FOS) was studied using a combined electroencephalography-functional magnetic resonance imaging (EEG-fMRI) technique. An automatic approach for combined EEG-fMRI analysis and a subject-specific hemodynamic response function was used to improve general linear model analysis of the fMRI data. The EEG showed the typical features of FOS, with continuous epileptiform discharges during elimination of central vision by eye opening and closing and fixation; modification of this pattern was clearly visible and recognizable. During all 3 recording sessions EEG-fMRI activations indicated a BOLD signal decrease related to epileptiform activity in the parietal areas. This study can further our understanding of this EEG phenomenon and can provide some insight into the reliability of the EEG-fMRI technique in localizing the irritative zone.

Ambulatory non‐convulsive status epilepticus evolving into a malignant form

We retrospectively analysed the clinical characteristics, electroencephalogram (EEG) records, brain magnetic resonance imaging (MRI) scans, antiepileptic therapy and prognosis of a case series with ambulatory non-convulsive status epilepticus (NCSE) which evolved into a malignant form (mNCSE). mNCSE was defined as NCSE that continues or recurs five days or more after the onset of general anaesthesia, including those cases where NCSE recurs upon reduction or withdrawal of anaesthetic therapy. Four women and two men were studied. The mean age was 42.8 years (range: 19-63 years). Two of six patients had a previous diagnosis of epilepsy. Four patients died. Two patients had a good outcome with return to consciousness and activities of daily life, and one of these subjects developed temporal lobe epilepsy. In four patients, the cause of mNCSE was encephalitis. Clinical presentation was complex partial status epilepticus (CPSE) in three patients and generalised NCSE (GNCSE) in the other three. Two of the latter had encephalitis and one was diagnosed with progressive myoclonus epilepsy (PME) of Lafora type. The mean duration of the NCSE episode was 47.5 days (range: 9-139 days; SD: 53.1). In three patients, continuous or rhythmic focal epileptiform discharges were the EEG pattern at onset. In the other three, continuous rhythmic generalised spike-wave, polyspike-wave or sharp slow-wave complexes were observed. Antiepileptic treatment was heterogeneous and patients were treated with an average of 6.0 AEDs (range: 3-10; SD: 3.0). In summary, mNCSE is a severe epileptic condition that occurs often in the context of encephalitis or pre-existing epilepsy. Both CPSE and GNCSE may occur. Although high mortality is associated with mNCSE, some patients may survive with normal or good recovery.

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.

Continuous Epileptiform Discharges in Patients Treated With Cefepime or Meropenem

To test the hypothesis that treatment with cefepime hydrochloride leads to higher incidence of periodic epileptiform discharges compared with treatment with other β-lactams. Data from hospital pharmacy databases of patients treated with cefepime or meropenem during a 42-month period (from January 1, 2007, through June 30, 2010) were retrospectively crossed with data from the electroencephalography database for the same period. Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium. Patients who underwent electroencephalographic testing while taking cefepime or meropenem were selected. Only electroencephalographic tests performed during the antibiotic treatment period were considered. Matches were compared with nurses' medication records to ensure that the antibiotic considered was effectively given. Proportions of patients with continuous epileptiform discharges in the 2 groups were compared using the Fisher exact test. A total of 1120 patients were treated with cefepime and 1572 patients with meropenem. Electroencephalographic testing was performed during treatment in 59 patients treated with cefepime and 80 treated with meropenem (5.26% vs 5.08%, P = .85). Continuous epileptiform discharges were present in 14 patients in the cefepime group and 3 in the meropenem group (1.25% vs 0.19%, P < .001). Blood creatinine concentration was elevated in 5 of the 17 patients (range, 1.5-4.2 mg/dL; reference range, 0.7-1.2 mg/dL), and liver enzyme levels were elevated in 5 patients. No patient had major electrolyte disturbances. Our study showed a prevalence of electroencephalographic test results with continuous epileptiform discharges in 14 of 1120 patients receiving cefepime (1.25%) but only 3 of 1572 patients receiving meropenem (0.19%). Contrary to the results of previous case series, these electroencephalographic patterns occurred, in most cases, in patients with normal renal function. These results suggest that cefepime may be an independent risk factor for periodic epileptiform discharges, which are associated with worse outcomes. This finding could provide a partial explanation for the higher mortality rates reported in patients treated with cefepime compared with other β-lactams.

Nonconvulsive Status Epilepticus During Perioperative Period of Cerebrovascular Surgery

Nonconvulsive status epilepticus (NCSE) is generally defined as a change in behavior and/or mental process from the baseline, which is associated with ongoing seizure activity or continuous epileptiform discharges on electroencephalography (EEG) in the absence of convulsive seizures. The present study investigated NCSE incidence using serial EEG during the perioperative periods of cerebrovascular surgery at a medium-sized, local hospital. A total of 54 patients were admitted to our department and underwent various neurosurgical procedures over a course of one year. If clinical symptoms worsened without clear explanation, EEG was performed, resulting in a diagnosis of NCSE in four patients (7.4%). The EEG abnormalities included periodic lateralized epileptiform discharges in 1 patient, triphasic waves in 2 patients, and repeated ictal discharges in 1 patient. Improved mental status and consciousness level, together with disappearance of EEG abnormalities, after appropriate anticonvulsant treatment supported the diagnosis of NCSE. The present study stressed the importance of EEG if no adequate explanation for neurological deterioration can be determined from the clinical course, laboratory data, or neuroimaging examination.

Nonconvulsive Status Epilepticus in Schizophrenia: Focus on Early Detection

Back to table of contents Previous article Next article LettersFull AccessNonconvulsive Status Epilepticus in Schizophrenia: Focus on Early DetectionChih-Sung Liang, M.D., and Fei-Wen Yang, M.D.Chih-Sung LiangSearch for more papers by this author, M.D., and Fei-Wen YangSearch for more papers by this author, M.D.Published Online:1 Oct 2011https://doi.org/10.1176/jnp.23.4.jnpe26AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To the Editor: Nonconvulsive status epilepticus (NCSE) as a condition with a change in consciousness associated with continuous epileptiform discharges in the EEG is easily treated but often underdiagnosed.1 This is partially explained by its absence of major motor signs and protean manifestations seen in nonepileptic disorders. We present a case of NCSE and highlight early detection of this condition in patients with schizophrenia.Case ReportA 64-year-old woman with schizophrenia, which was well managed by risperidone 4 mg/day, fludiazepam 0.75 mg/day, and flunitrazepam 2 mg/day in recent years, was brought to the emergency department because of an abrupt onset of an altered level of consciousness, irritability, and psychosis. Laboratory results showed hyponatremia (115 mmol/liter) and hypokalemia (2.6 mmol/liter). Otherwise, abdominal ultrasonography, brain CT, CSF analysis, and other examinations revealed no remarkable findings. The family reported that for the past few days, there had been a marked excess of water intake. With a diagnosis of polydipsia-induced hyponatremia, she was admitted for electrolyte replacement.Upon admission, the treating physicians instantly discontinued all psychotropics. Because her condition did not improve even as her serum sodium and potassium concentrations were restored, psychiatric consultation was requested on Hospital Day 4. A diagnosis of delirium was made, and risperidone 4 mg/day was resumed. Her condition, however, gradually worsened. On Hospital Day 7, an EEG was obtained, which revealed generalized epileptiform discharges. The brain MRI showed negative findings. Consultation with a neurologist resulted in a diagnosis of NCSE; a regimen of levetiracetam 1,500 mg/day and intravenous valproic acid 1,200 mg/day was started, and risperidone was withheld. Four days after the initiation of antiepileptic agents, the patient's condition was notably improved. An EEG performed subsequently did not show any further epileptiform discharges.DiscussionThis case illustrates the complexities involved in distinguishing NCSE from other causes contributing to the development of delirium. Considering NCSE as a cause of delirium without an EEG is a great challenge because of the significant overlap in clinical features between NCSE and delirium. Misdiagnosis of NCSE could place psychiatrists at risk of iatrogenic error, because delayed treatment or exposure to antipsychotic agents that could lower seizure threshold might aggravate NCSE. Benzodiazepine (BZD) withdrawal, antipsychotic treatment, and delay in diagnosis might have worked in combination to exacerbate this patient's NCSE. Evidence demonstrates that patients with schizophrenia are more likely to experience seizures because of comorbid substance abuse, long-term exposure to psychotropic agents, and frequent episodes of head injury.2 Also, the behavioral and mental status changes of NCSE may incorrectly be ascribed to psychotic symptoms. A variety of precipitating factors have been implicated in NCSE, including polydipsia-induced hyponatremia,3 a previous history of seizures,1 infection,1 ECT,4 and BZD withdrawal,5 all of which are commonly associated with either the treatment of or are common comorbidities with schizophrenia.In conclusion, when evaluating patients with schizophrenia who have developed altered mental status and behavior, psychiatrists should pay more attention to whether an emergent EEG is needed in order to confirm or exclude the diagnosis of NCSE.Department of Psychiatry Beitou Armed Forces Hospital Taipei, Taiwan (R.O.C.)Correspondence: Fei-Wen Yang, M.D. Department of Psychiatry Beitou Armed Forces Hospital Taipei, Taiwan (R.O.C.) e-mail: [email protected]com.tw1. Meierkord H , Holtkamp M : Non-convulsive status epilepticus in adults: clinical forms and treatment. Lancet Neurol 2007; 6:329–339Crossref, Medline, Google Scholar2. Hyde TM , Weinberger DR : Seizures and schizophrenia. Schizophr Bull 1997; 23:611–622Crossref, Medline, Google Scholar3. Azuma H , Akechi T , Furukawa TA : Absence status associated with focal activity and polydipsia-induced hyponatremia. Neuropsychiatr Dis Treat 2008; 4:495–498Crossref, Medline, Google Scholar4. Povlsen UJ , Wildschiodtz G , Hogenhaven H , et al.: Nonconvulsive status epilepticus after electroconvulsive therapy. J ECT 2003; 19:164–169Crossref, Medline, Google Scholar5. Olnes MJ , Golding A , Kaplan PW : Nonconvulsive status epilepticus resulting from benzodiazepine withdrawal. Ann Intern Med 2003; 139:956–958Crossref, Medline, Google Scholar FiguresReferencesCited byDetailsCited ByDe-novo non-convulsive status epilepticus in adult medical inpatients without known epilepsy: Analysis of mortality related factors and literature review15 October 2021 | PLOS ONE, Vol. 16, No. 10 Volume 23Issue 4 Fall 2011Pages E26-E26 Metrics PDF download History Published online 1 October 2011 Published in print 1 October 2011