Suspicion Of Nonconvulsive Status Epilepticus Research Articles

Stimulus-induced arousal with transient electroencephalographic improvement distinguishes nonictal from ictal generalized periodic discharges.

In the case of suspicion of nonconvulsive status epilepticus (NCSE), reactivity on electroencephalograms (EEGs) can provide valuable diagnostic information. Reactivity refers to responses to auditory or somatosensory stimulation, with changes in amplitude and frequency of background activity. Because of self-perpetuating processes and the failure of self-terminating mechanisms, status epilepticus is unlikely to cease when patients spontaneously move, and it cannot typically be stopped by external stimulation (i.e., auditory and tactile stimuli). The defining EEG characteristic of absence status epilepticus is the presence of bilateral, synchronous, symmetric, rhythmic paroxysmal activity that shows little or no reactivity to sensory stimulation. On the other hand, in metabolic/toxic or multifactorial encephalopathies, triphasic waves (TWs) are influenced by the level of vigilance. TWs may be transiently abolished when patients increase their level of alertness from a drowsy/lethargic state to a state of wakefulness. This reactivity is only observed when patients can be aroused by a somatosensory or auditory stimulus. This reactivity tends to disappear with increasing severity of the disease and in comatose patients. In patients without preexisting developmental and epileptic encephalopathy, this pattern of stimulus-induced wakefulness with transient improvement of the EEG is a major criterion in determining that the EEG patterns are not ictal. This criterion of reactivity on EEGs, beyond the classical clinical/EEG criteria of NCSE (Salzburg criteria), should now be systematically added.

Salzburg Criteria, A Useful Tool in Non-Convulsive Status Epilepticus Diagnosis: A Retrospective Study.

Introduction. Non-convulsive status epilepticus (NCSE) has been traditionally a challenging electroencephalographic (EEG) diagnosis. For this reason, Salzburg consensus criteria (SCC) have been proposed to facilitate correct diagnosis. Methods. We retrospectively reanalyzed 41 cases referred to our department (from 2016 to 2018) under the suspicion of NCSE. In this study, we compared the original description (standard criteria) versus the updated description (SCC) of the same EEG. Results. Originally, 15 patients were diagnosed as NCSE (37%) and 26 patients as no NCSE (63%), using the standard criteria. Then, we analyzed EEGs according to the SCC, which led to the following results: 9 patients fulfilled the criteria for definite NCSE (22%), 20 patients were diagnosed as possible NCSE (49%) and 12 patients were diagnosed as no NCSE (29%). Subsequently, when we analyze the outcome of possible NCSE cases, we note that 50% of these patients presented mild-poor outcome (neurological deficits, deceased). Indeed, we observed worse outcomes in patients previously diagnosed as no NCSE and untreated, specifically post-anoxic cases. Conclusions. Salzburg criteria seem to be a useful tool to support NCSE diagnosis, introducing the category of possible NCSE. In our study, we observed that it contributes to improving the prognosis and management of the patients. However, more prospective studies are needed to demonstrate the accuracy of SCC.

Usefulness of electroencephalography for the management of epilepsy in emergency departments

IntroductionElectroencephalography (EEG) is an essential diagnostic tool in epilepsy. Its use in emergency departments (ED) is usually restricted to the diagnosis and management of non-convulsive status epilepticus (NCSE). However, EDs may also benefit from EEG in the context of other situations in epilepsy. MethodsWe conducted a retrospective observational study using the clinical histories of patients treated at our hospital's ED for epileptic seizures and suspicion of NCSE and undergoing EEG studies in 2015 and 2016. We collected a series of demographic and clinical variables. ResultsOur sample included 87 patients (mean age of 44 years). Epileptic seizures constituted the most common reason for consultation: 59.8% due to the first episode of epileptic seizures (FES), 27.6% due to recurrence, and 12.6% due to suspected NCSE. Interictal epileptiform discharges (IED) were observed in 38.4% of patients reporting FES and in 33.3% of those with a known diagnosis of epilepsy. NCSE was confirmed by EEG in 36.4% of all cases of suspected NCSE. Presence of IED led to administration of or changes in long-term treatment in 59.8% of the patients. ConclusionsEEG is a useful tool for seizure management in EDs, not only for severe, sudden-onset clinical situations such as NCSE but also for diagnosis in cases of non-affiliated epilepsy and in patients experiencing the first episode of epilepsy.

Nonconvulsive Status Epilepticus: Validating the Salzburg Criteria Against an Expert EEG Examiner.

Rapid and correct diagnosis of nonconvulsive status epilepticus (NCSE) is crucial for optimal treatment. However, electroencephalographic diagnosis can be challenging. Salzburg Consensus Criteria (SCC) have been proposed to facilitate correct diagnosis, but their validity needs to be further established. We retrospectively reanalyzed the first EEG in adult patients (n = 284) referred under the suspicion of NCSE at our institution in 2014. Nonconvulsive status epilepticus or possible NCSE was diagnosed according to the SCC by an examiner specifically trained in SCC and was compared with the original diagnosis made by an expert EEG examiner, which in this context served as the reference standard, to assess the validity of the criteria. Furthermore, the clinical outcome for patients not diagnosed using SCC (false-negatives) was examined. Nonconvulsive status epilepticus or possible NCSE was diagnosed in 40 patients by the inexperienced reader using the SCC, blinded to other clinical data, and in 47 patients by the experienced reader, not blinded to the clinical data, who did not use SCC. There were eight false-negatives, one false-positive, 39 true-positives, and 236 true-negatives. Concordance between SCC and the reference standard was high (k = 0.88 [95% confidence interval, 0.80 to 0.96]). Four of the eight false-negatives suffered from anoxic encephalopathy. The remainder had a history of epilepsy and returned to preictal functional state. The SCC for NCSE implemented by an inexperienced EEG reader, blinded to all other data, yielded results highly concordant with the evaluation of EEG by an experienced reader. False-negative diagnoses were associated with postictal states or anoxic encephalopathy.

État de mal épileptiques : avancées récentes

About half of status epilepticus (SE) occur in patients without epilepsy. An EEG has to be performed quickly in any patient who remains unconscious after the end of convulsions with the aim to detect a subtle status. An EEG should be performed as soon as possible in case of suspicion of non-convulsive status epilepticus, or in case of a confusional state whose origin remains unknown. The realization of a cerebral imaging is very often necessary in case of inaugural SE, as soon as the patient's condition allow it. It is also often indicated in case of known epilepsy. The main differential diagnosis of convulsive SE is psychogenic non-epileptic status. In non-convulsive status epilepticus, the use of anesthetic agents should be considered only rarely, as the risks of such an approach are often greater than the expected benefits.

Utilidad del electroencefalograma en el manejo de la epilepsia en el Servicio de Urgencias

IntroductionElectroencephalography (EEG) is an essential diagnostic tool in epilepsy. Its use in emergency departments (ED) is usually restricted to the diagnosis and management of non-convulsive status epilepticus (NCSE). However, EDs may also benefit from EEG in the context of other situations in epilepsy. MethodsWe conducted a retrospective observational study using the clinical histories of patients treated at our hospital's ED for epileptic seizures and suspicion of NCSE and undergoing EEG studies in 2015 and 2016. We collected a series of demographic and clinical variables. ResultsOur sample included 87 patients (mean age of 44 years). Epileptic seizures constituted the most common reason for consultation: 59.8% due to the first episode of epileptic seizures (FES), 27.6% due to recurrence, and 12.6% due to suspected NCSE. Interictal epileptiform discharges (IED) were observed in 38.4% of patients reporting FES and in 33.3% of those with a known diagnosis of epilepsy. NCSE was confirmed by EEG in 36.4% of all cases of suspected NCSE. Presence of IED led to administration of or changes in long-term treatment in 59.8% of the patients. ConclusionsEEG is a useful tool for seizure management in EDs, not only for severe, sudden-onset clinical situations such as NCSE but also for diagnosis in cases of non-affiliated epilepsy and in patients experiencing the first episode of epilepsy.

O29 EEG criteria of non-convulsive status epilepticus

Objectives A panel of experts, in 2013, at the 4th Colloquium on Status Epilepticus in Salzburg, proposed a set of EEG criteria for nonconvulsive status epilepticus (NCSE), known as the Salzburg-criteria for NCSE. The objective was to validate these criteria. Methods We did a diagnostic study where two raters blinded to all other patient data analysed EEG recordings from participants admitted three centres ( n = 220). Participants were placed into one of two groups: the clinical validation group which consisted of consecutive patients with clinical suspicion of NCSE referred to EEG recording ( n = 120), or the control group which consisted of consecutive patients with abnormal EEG-findings, but without clinical suspicion of NCSE ( n = 100). The reference standard was inferred from all clinical and para-clinical data, therapeutic response, and final outcome, as evaluated by two raters who were blinded to diagnosis according to the Salzburg-criteria. Results In the clinical validation group, sensitivity was 97.7% and specificity was 89.6% (overall accuracy: 92.5%). In the control group, specificity was 97%; sensitivity was not calculated in this group as the reference standard did not confirm NCSE in any of the control patients. Inter-rater agreement (IRA) was high, both for Salzburg-criteria ( k = 0.87) and for the reference standard ( k = 0.95). Therapeutic changes were seen significantly more often in the group of patients fulfilling Salzburg-criteria (84%) as compared to patients who did not (16%). Significance Salzburg-criteria for NCSE have high diagnostic accuracy and excellent IRA, making them suitable for implementation in clinical practice.

P488: Acute brachial plexus neuropathy with involvement of cranial nerves IX, X, XI and XII: diagnostic value of MRI

During first three days, he gradually got comatose. EEG showed generalized continuous slow waves. We started potent antibiotics and added antiepileptic drugs in the suspicion of non-convulsive status epilepticus (NCSE). Full work up to find causative etiology including viruses, bacteria, rickettsia, fungus, auto-antibodies was done, but none of them was positive. After 10 days, he remained comatose and quadriplegic despite full dose of antimicrobial treatment. 2 weeks after admission, intravenous immunoglobulin was given in 0.4g/kg for 5 days, but there was no neurologic improvement. Follow up EEG showed no change. Case 2: A 16 year old previously healthy man suffered from drowsiness preceded by fever and headache from 5 days ago. CSF analysis showed pleocytosis with predominate lymphocytes. Initial MRI image was normal. We started acyclovir 10mg/kg three times a day. After two days, his gradually got comatose and quadriparetic. EEG showed generalized continuous slow waves. We added antibiotics and antiepileptic drugs, and checked up for possible etiologies, but nothing was positive. Follow up MRI image showed T2 high signal in bilateral thalamus, basal ganglia, and brainstem. At the fifth day of admission, we started intravenous steroid 1g for 5 days and intravenous immunoglobulin 0.4g/kg for 5 days, successively. After administration of steroid, the patient got alert and oriented, and general weakness gradually diminished. Follow up EEG also returned to normal. Discussion: High proportion of etiology-unidentified encephalitis is due to incomplete study or late seroconversion. We suggest that most of encephalitis classified as by unknown cause are undiagnosed cases of major etiologies, such as HSV encephalitis, or ADEM. So we should consider inducing immune-modulation simultaneously with the antimicrobial therapy, if neurologic status deteriorates despite improvement of CSF profile. And the response can be followed up by EEG. P488 Acute brachial plexus neuropathy with involvement of cranial nerves IX, X, XI and XII: diagnostic value of MRI

EEG features of nonconvulsive status epilepticus

Nonconvulsive status epilepticus (NCSE) is diagnosed in practice as an enduring epileptic condition with reduced or altered consciousness, but without major convulsive movements, and epileptiform discharges on EEG. In this article, an illustrative and paradigmatic case is presented with a focus on the main EEG features which should be considered when there is clinical suspicion of NCSE. Some clinical and neurophysiological tips are also provided in order to effectively differentiate between NCSE and other conditions. The clinical suspicion of NCSE may be supported by EEG recordings showing rhythmic and dynamic epileptiform activity. However, although a definitive diagnosis of NCSE cannot be made without EEG-based evidence, the "ultimate diagnosis" of NCSE relies on both neurophysiological and clinical features.

Counterpoint: Emergency (“Stat”) EEG in the Era of Nonconvulsive Status Epilepticus

ABSTRACTThe most widely accepted indication for a stat EEG (stEEG) is the suspicion of nonconvulsive status epilepticus (NCSE). NCSE has been reported with surprising frequency in a wide variety of acute structural and metabolic brain injuries and significantly increases the risk of permanent brain damage and death. This risk rises and the effectiveness of treatment decreases with delays in diagnosis and increased duration of NCSE. Recent evidence confirms that more than half of NCSE patients improve with anti-seizure treatment. The emergence of NCSE as a common, dangerous, time-urgent, and treatable problem has positioned it as a target for emergency therapeutic intervention. NCSE can only be diagnosed by EEG testing, and stEEG has demonstrated value in improving NCSE management. As a result, in the near future, EEG laboratories will see increasing demands for stEEG related to NCSE. The two main obstacles to an effective stEEG program are EEG technologist coverage and electroencephalographer availability after work hours. We recommend three simple but fundamental changes in the traditional approach to stEEGs in order to overcome these obstacles: the use of EEG set-up templates by onsite personnel, easy access to EEG instruments after hours, and remote stEEG connectivity for real-time, off-site electroencephalographer interpretation.