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.

Ictal EEG: Etiology and Mortality in Older Adults With Nonconvulsive Status Epilepticus

Clinical-electroencephalogram (EEG), as well as etiological and prognostic data on subtypes of nonconvulsive status epilepticus (NCSE) are yet to be established. Objective: Evaluate the clinical semiology and EEG findings and prognostic data of older adults with NCSE. Methodology: Characterize the clinical-EEG and prognostic data in the subtypes of NCSE in older adults consecutively admitted to the emergency room of the Pontifícia Universidade Católica de Campinas (PUC-Campinas) University Hospital. Results: When evaluating 105 older adults with altered consciousness, it was possible to diagnose NCSE in 50 (47.6%) older adults, with a mean age of 72.8 ± 8.8 years. NCSE-coma occurred in 6 cases, with NCSE-without coma in 44 cases. The etiology was structural in 41(82%) cases, metabolic in 5 cases, and unknown etiology in 4 cases. Twelve cases had a history of epileptic seizures. On the EEG, epileptiform discharges (EDs > 2.5 Hz) were present in 34(68%) cases and rhythmic delta activity /lateralized periodic patterns occurred in 35(70%) cases. There was clinical improvement after the initial pharmacological treatment in 36 cases and, within 30 days, 18 cases died. The better prognosis was associated with a good response to initial pharmacological treatment (n = 14) and with EDs > 2.5 Hz on EEG (Fisher's exact test; 26 vs 8; P = .012). Conclusion: Focal NCSE with impaired consciousness was the most frequent subtype. The most frequent finding on the EEG was the recording of focal/regional seizures. A high number of cases showed initial clinical improvement, but mortality was high. The favorable prognosis was associated with initial clinical improvement and the presence of EDs > 2.5 Hz. There was no relationship between EEG patterns and the etiology and subtypes of NCSE in older adults.

Nonconvulsive Status Epilepticus: A Review for Emergency Clinicians

BACKGROUND

Status epilepticus is associated with significant morbidity and mortality and is divided into convulsive status epilepticus and nonconvulsive status epilepticus (NCSE).

OBJECTIVE

This review provides a focused evaluation of NCSE for emergency clinicians.

DISCUSSION

NCSE is a form of status epilepticus presenting with prolonged seizure activity. This disease is underdiagnosed, as it presents with nonspecific signs and symptoms, most commonly change in mental status without overt convulsive motor activity. Causes include epilepsy, cerebral pathology or injury, any systemic insult such as infection, and drugs or toxins. Mortality is primarily related to the underlying condition. Patients most commonly present with altered mental status, but other signs and symptoms include abnormal ocular movements and automatisms such as lip smacking or subtle motor twitches in the face or extremities. The diagnosis is divided into electrographic and electroclinical, and although electroencephalogram (EEG) is recommended for definitive diagnosis, emergency clinicians should consider this disease in patients with prolonged postictal state after a seizure with no improvement in mental status, altered mental status with acute cerebral pathology (e.g., stroke, hypoxic brain injury), and unexplained altered mental status. Assessment includes laboratory evaluation and neuroimaging with EEG. Management includes treating life-threatening conditions, including compromise of the airway, hypoglycemia, hyponatremia, and hypo- or hyperthermia, followed by rapid cessation of the seizure activity with benzodiazepines and other antiseizure medications.

CONCLUSIONS

An understanding of the presentation and management of NCSE can assist emergency clinicians in the care of these patients.

Nonconvulsive status epilepticus in neurocritical care: A critical reappraisal of outcome prediction scores

OBJECTIVE

Nonconvulsive status epilepticus (NCSE) is a frequent condition in the neurocritical care unit (NCCU) patient population, with high morbidity and mortality. We aimed to assess the validity of available outcome prediction scores for prognostication in an NCCU patient population in relation to their admission reason (NCSE vs. non-NCSE related).

METHODS

All 196 consecutive patients diagnosed with NCSE during the NCCU stay between January 2010 and December 2020 were included. Demographics, Simplified Acute Physiology Score II (SAPS II), NCSE characteristics, and in-hospital and 3-month outcome were extracted from the electronic charts. Status Epilepticus Severity Score (STESS), Epidemiology-Based Mortality Score in Status Epilepticus (EMSE), and encephalitis, NCSE, diazepam resistance, imaging features, and tracheal intubation score (END-IT) were evaluated as previously described. Univariable and multivariable analysis and comparison of sensitivity/specificity/positive and negative predictive values/accuracy were performed.

RESULTS

A total of 30.1% died during the hospital stay, and 63.5% of survivors did not achieve favorable outcome at 3 months after onset of NCSE. Patients admitted primarily due to NCSE had longer NCSE duration and were more likely to be intubated at diagnosis. The receiver operating characteristic (ROC) for SAPS II, EMSE, and STESS when predicting mortality was between .683 and .762. The ROC for SAPS II, EMSE, STESS, and END-IT when predicting 3-month outcome was between .649 and .710. The accuracy in predicting mortality/outcome was low, when considering both proposed cutoffs and optimized cutoffs (estimated using the Youden Index) as well as when adjusting for admission reason.

SIGNIFICANCE

The scores EMSE, STESS, and END-IT perform poorly when predicting outcome of patients with NCSE in an NCCU environment. They should be interpreted cautiously and only in conjunction with other clinical data in this particular patient group.

Evaluation of Nonconvulsive Status Epilepticus and Nonconvulsive Seizures in a Pediatric Intensive Care Unit

We aimed to identify nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) in a pediatric intensive care unit (PICU). A prospective cohort study on 35 patients who underwent continuous electroencephalographic monitoring in the PICU was done. The patients were evaluated to collect data of their demographics, clinical diagnoses, clinical seizures by electroencephalography, and neuroimaging findings. One case with NCSE and 4 cases with NCS were diagnosed among the 35 patients. The etiology of the patient with NCSE showed antiepileptic drug (AED) withdrawal. The etiology of the patients with NCS included electrical injury, head trauma, subarachnoid hemorrhage, and pneumonia. The findings suggest that younger age, epilepsy, acute structural brain abnormalities, abrupt cessation of AED, and clinically overt seizures before NCSE/NCS are associated with significant risk for NCS/NCSE. In addition, the electrical injury may also be considered as a risk factor for electrographic seizure though such a case has not yet been reported.

Infantile Hypoxic Encephalopathy Mimicking Acute Encephalopathy with Biphasic Seizures and Late Reduced Diffusion (AESD) Identified as an Episode of Brief Resolved Unexplained Event (BRUE)

Acute encephalopathy with biphasic seizures and reduced diffusion (AESD) is characterized by biphasic seizures following febrile viral infections and delayed reduced diffusion of the cerebral white matter on magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) (bright tree appearance, BTA). However, hypoxic encephalopathy with biphasic seizures and AESD-mimicking imaging findings has not been reported. We report a case of hypoxic encephalopathy due to suffocation with concomitant biphasic seizures and BTA, mimicking AESD. On day 1, a healthy 5-month-old girl was found face down with decreased breathing and a deteriorating consciousness level, suggesting a brief resolved unexplained event (BRUE). Electroencephalography (EEG) revealed periodic epileptic discharges, suggesting possible nonconvulsive status epilepticus. Despite improvements in consciousness level and EEG abnormalities on day 2, her consciousness level deteriorated again with generalized tonic-clonic seizures on day 3, and a head MRI-DWI revealed restricted diffusion predominantly in the subcortical areas, suggesting BTA. Treatment for acute encephalopathy resolved the clinical seizures and EEG abnormalities. Persistence of abnormal EEG, reflecting abnormal excitation and accumulation of neurotoxic substances caused by hypoxia, may have contributed to the development of AESD-like findings. As hypoxic encephalopathy causes AESD-like biphasic seizures, monitoring consciousness level, seizure occurrence, and EEG abnormalities even after acute symptoms have temporarily improved following hypoxia is essential.

Nonconvulsive Status Epilepticus Associated with Cerebral Hyperperfusion Syndrome after Carotid Endarterectomy: A Case Report

We report a case of a 73-year-old man who developed nonconvulsive status epilepticus as a complication of cerebral hyperperfusion syndrome after carotid endarterectomy for carotid artery stenosis. On postoperative day 1, the patient experienced headaches and vomiting. Resting N-isopropyl-p-[¹²³I] iodoamphetamine single-photon emission computed tomography showed increased cerebral blood flow to the entire right hemisphere, and the patient was diagnosed with cerebral hyperperfusion syndrome. He was treated with antihypertensive and antiseizure medications, sedated using propofol, intubated, and placed under mechanical ventilation. On postoperative day 3, computed tomography perfusion imaging showed a reduction in hyperperfusion, and propofol sedation was terminated on postoperative day 4. However, the patient exhibited prolonged impaired awareness and roving eye movements, and long-term video electroencephalographic monitoring revealed electrographic seizures. The patient was diagnosed with nonconvulsive status epilepticus. Propofol sedation was resumed, and the antiseizure medication dose was increased. Subsequently, the state of hyperperfusion in the right hemisphere diminished, and electroencephalographic findings improved, allowing sedation to be terminated on postoperative day 7. The findings from this case suggest that when clinical subtle symptoms, such as impaired awareness and roving eye movements, are observed during treatment of cerebral hyperperfusion syndrome, video electroencephalography should be performed to detect electrographic seizures.

Nonconvulsive status epilepticus as an unusual presentation of tuberculous meningoencephalitis: A case report

We describe a 50-year-old woman who was recently diagnosed with tuberculosis, with acute alteration in mental status. EEG showed nonconvulsive status epilepticus features. Brain MRI revealed multiple ring-enhancing lesions. She responded well to treatment for both status epilepticus and tuberculosis. Her level of consciousness improved and she became fully aware.

[A case of Creutzfeldt-Jakob disease presenting with nonconvulsive status epilepticus in the early stages]

A 64-year-old Japanese woman presented with 1 week of recurrent convulsive seizures. At the time of admission, she was in a coma and did not present with convulsions. Intravenous diazepam administration improved her consciousness, although severe psychomotor excitement developed. Brain MRI demonstrated diffusion restriction in the cerebral cortex of the right hemisphere. Electroencephalography (EEG) showed periodic discharges centered around the parietal regions with right-sided dominance. Nonconvulsive status epilepticus (NCSE) was suspected, and the patient was actively treated with anti-epileptic drugs. She developed akinetic mutism and generalized myoclonus 1 month after admission. Follow-up EEG studies disclosed periodic synchronous discharges. Abnormal prion protein in the cerebral fluid was detected using a real-time quaking-induced conversion assay. The clinical diagnosis in the present case was sporadic Creutzfeldt-Jakob disease (CJD). Seizures as an initial symptom in patients with CJD are relatively rare. Our case suggests that CJD should be considered as a differential diagnosis when a patient presents with refractory NCSE.

New-onset non-lesional aphasic status epilepticus. Clinical description, diagnostic clues, and treatment algorithm

OBJECTIVES

De novo aphasic status epilepticus (ASE) in patients without a previous history of epilepsy and without cerebral lesions (aphasic NOSE) is rare. The aim of the study is to describe its clinical characteristics, etiologies, and outcome.

MATERIALS & METHODS

Single-center study including consecutive patients presenting to the emergency department between 2011 and 2019 with acute aphasia, which was finally diagnosed as aphasic NOSE. Subsequent episodes of aphasia (>5 min) were recorded and divided into confirmed ASE and postictal aphasic episodes (non-ASE). Clinical characteristics of the two types of episodes were compared.

RESULTS

Nineteen patients were included, suffering fifty episodes of epileptic aphasia, episodes per patient 2.6 (range 1-7). Fifteen patients (71.4%) were women, mean age at ASE onset was 66.05 years old (SD 6.3). Nine (47%) patients died, 6 of them (66.7%) during the aphasic episode. Ictal EEG was available in 37 episodes, confirming the diagnosis of ASE in 12 episodes; in 8 episodes, the EEG fulfilled the criteria of possible ASE. The most frequent etiologies were inflammatory and vascular. Comparing ASE with non-ASE episodes, ASE was longer than non-ASE (225 vs 65 h, p .024) and was treated more frequently with BZD (76 vs 24%, p .001) but with a longer delay (22.2 vs 1.5 h, p .06).

CONCLUSIONS

ASE is a treatable, highly relapsing emergency, with the subsequent relapses ASE or postictal aphasia. EEG is diagnostic in half of the patients, while in others imaging techniques are also useful. Benzodiazepines should be administered. Persistent aphasia, of more than 65 hours' duration, is highly suggestive of ASE.

Lateralized Periodic Discharges in a Patient With Dural Arteriovenous Fistula: SPECT and DWI Studies Suggest They are Ictal

Lateralized periodic discharges (LPDs) are unilateral electroencephalography (EEG) waveforms, recurring at regular intervals. There has been a long-lasting debate about whether they represent ictal or interictal phenomena. Very few patients in the literature have been investigated with multimodal functional imaging techniques. Here, we present a 58-year-old male patient with symptomatic epilepsy who had cerebral venous sinus thrombosis in the right temporo-parietal area and dural arteriovenous fistula (dAVF) over the left fronto-parietal region. He developed acute speech disturbances and altered mental status after a generalized tonic-clonic seizure. Video-EEG monitoring (VEEGM) demonstrated LPDs over the left fronto-central area, overlapping in part with the dAVF. Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) sequences revealed restricted diffusion compatible with cytotoxic edema, whereas single-photon emission computed tomography (SPECT) indicated hyperperfusion in the same region, leading to the conclusion that he was having possible nonconvulsive status epilepticus (NCSE). An increase in antiseizure medications led to gradual improvement in clinical status and the disappearance of LPDs.

Nonconvulsive Status Epilepticus Caused by Cerebrospinal Fluid Dissemination of a Salivary Duct Carcinoma: A Case Report

Salivary duct carcinoma (SDC) is a rare and highly aggressive salivary gland tumor with rapid growth, distant metastasis, and a high recurrence rate. Moreover, the parotid gland is the most common site with a poor prognosis. A lower frequency of distance metastasis to the liver, skin, and brain has also been reported, although the lungs, bones, and lymph nodes are the most common sites of SDC metastasis. We report a case of nonconvulsive status epilepticus (NCSE) in a 73-year-old male comatose patient having SDC of the parotid gland with an unusual metastasis to the skin and brain diagnosed by frequent cerebrospinal fluid examinations. Meningeal carcinomatosis usually has a poor prognosis, and NCSE is a reversible cause of altered mentation. Clinicians should know the unique set of epilepsy etiologies in patients with malignant tumors.

[MRI arterial spin labeling is useful for diagnosing recovery from nonconvulsive status epilepticus with sustained periodic discharges]

A 75-year-old man with a history of temporal lobe epilepsy (treated with levetiracetam) was transferred to our hospital because of loss of consciousness. At admission, he was drowsy and exhibited myoclonus on the left side of face. We established a diagnosis of status epilepticus and started treatment with levetiracetam, fosphenytoin, and midazolam. FLAIR and DWI showed hyperintensity in the right cerebral cortex. Electroencephalography (EEG) showed lateralized periodic discharges (LPDs) at the right hemisphere, indicative of non-convulsive status epilepticus (NCSE). He regained consciousness after treatment with anti-epileptic drugs but showed persistent LPDs in EEG. MRI arterial spin labeling (ASL) showed normal perfusion in the right hemisphere; therefore, he was deemed to have recovered from status epilepticus and transferred to the rehabilitation hospital. MRI ASL is useful for diagnosing recovery from NCSE irrespective of sustained periodic discharges on EEG.

Functional neuroimaging in nonepileptiform electroencephalographic patterns in status epilepticus

BACKGROUND

The diagnosis of nonconvulsive status epilepticus (NCSE) in patients with nonepileptiform EEG patterns remains a challenge.

OBJECTIVE

To evaluate the usefulness of single photon emission computerized tomography (SPECT) and its quantification (QtSPECT) in the diagnosis of NCSE.

METHODS

We retrospectively reviewed patients admitted with clinical suspicion of NCSE who underwent an HMPAO-SPECT simultaneously with scalp EEG showing nonepileptiform patterns, in a 5-year period. After a complete diagnostic workup, treatment, and clinical evolution, disregarding the SPECT results, patients were classified into confirmed NCSE (n = 11) and non-NCSE (n = 8). Then, we compared the EEG and SPECT results in both groups.

RESULTS

Lateralized rhythmic delta activity (LRDA) was predominant in the NCSE group (45.4%, p = .045), while lateralized irregular slowing was observed equally in both groups. Patients with NCSE showed significant hyperperfusion compared with non-NCSE patients (p = .026). QtSPECT correctly classified 91% of patients in NCSE and 75% patients with non-NCSE (p = .006).

CONCLUSIONS

Regional cerebral blood flow measured with SPECT could be useful in the diagnosis of NCSE in cases of an EEG pattern with lateralized slow activity and high clinical suspicion.

Frequency and Types of Complications Encountered in Patients With Nonconvulsive Status Epilepticus in the Neurological ICU: Impact on Outcome

Objectives. The frequency and types of complications in patients with nonconvulsive status epilepticus (NCSE) who are followed up in the intensive care unit (ICU), and the impact of these complications on outcome are not well-known. We investigated the complications and their effects on prognosis in NCSE patients. Methods. After reviewing the video-EEG monitoring (VEEGM) reports of all the consecutive patients who were followed up in our ICU between 2009 and 2019, we identified two groups of patients: 1-patients with NCSE (study group) and 2-patients who underwent VEEGM for possible NCSE but did not have ictal recordings (no-NCSE group). Electronic health records were reviewed to identify demographic and clinical data, duration of ICU care, medical and surgical complications, pharmacologic treatment, and outcome. These parameters were compared statistically between the groups. We also investigated the parameters affecting prognosis at discharge. Results. Thirty-two patients with NCSE comprised the study group. Infection developed in 84%. More than half were intubated, had tracheostomy or percutaneous endoscopic gastrostomy application. Refractory NCSE was associated with significantly more frequent complications and worse outcome. There was a higher tendency of infections in the study group (P = .059). Higher organ failure scores and prolonged stay in ICU predicted worse outcome (P < .05). Conclusion. The frequency of complications in patients with NCSE who are cared for in the ICU is considerable. Most of the complications are similar to the other patients in ICU, except for the higher frequency of infections. Increased physician awareness about modifiable parameters and timely interventions might help improve prognosis.

Case Report: Hypopituitarism Presenting With Nonconvulsive Status Epilepticus

Introduction: Hypopituitarism is defined as one or more partial or complete pituitary hormone deficiencies. Nonconvulsive status epilepticus (NCSE) refers to a state of continuous or repetitive seizures without convulsions. In this paper, we review a case of an old female patient with hypopituitarism who presented with NCSE, which is rare in the clinic.

Case Report: This paper describes a 67-year-old female patient with hypopituitarism who presented as NCSE. She had surgical resection of pituitary tumor half a year before the seizures and did not get regular hormone replacement therapy. She presented general convulsive status epilepsy as the initial symptom and got sedation and antiepileptic drug in the emergency room. The seizure was terminated but the patient fell in coma in the following days. The patient had magnetic resonance imaging (MRI) and other inspects, and EEG showed epileptic discharges. Combining these clinical symptoms and examinations, we made the diagnosis of NCSE. Finally, she regained consciousness after the treatment with diazepam.

Conclusion: This case report and literature review investigated the possible mechanism of hypopituitarism presenting with NCSE.

Unilateral catalepsy in non-convulsive status epilepticus

Catalepsy is defined as a loss of motor and it is listed among the clinical features associated with catatonic syndrome and may occur in association with both psychiatric and neurological disorders. Isolated catalepsy represents a much rarer phenomenon, and has been occasionally reported due to focal brain injuries (e.g. strokes) involving either cortical or subcortical regions. Here, we describe the case of an 81-year-old man presenting with isolated unilateral catalepsy as the main manifestation of focal non-convulsive status epilepticus, ipsilateral to the cataleptic limbs. To our knowledge, this is the first report of ictal catalepsy, which highlights the need to consider epilepsy in the diagnostic algorithm for both hyper- and hypokinetic movement disorders.

Efficacy and Safety of Ketamine in Refractory/Super-refractory Nonconvulsive Status Epilepticus: Single-Center Experience

Refractory/super-refractory nonconvulsive status epilepticus (r/srNCSE) is an acute life-threatening neurocritical entity with significant morbidity. Failure to control SE in its earlier stages leads to multiple molecular alterations in the brain such as downregulation of GABA-A and upregulation of NMDA receptors. Recently ketamine, an NMDA receptor antagonist, has gained increased attention as a therapeutic choice in controlling refractory/super-refractory SE. We aimed to analyze the efficacy and safety profile of ketamine in our center. We retrospectively identified all the patients with nonconvulsive SE who received ketamine during their follow-up in our neurological intensive care unit between 2009 and 2019. Information about demographic, clinical, and laboratory findings; concurrent antiseizure and anesthetic medications; time of initiation, dose and duration of ketamine infusion; any adverse effects and finally prognosis were collected. The effect of day of ketamine initiation and duration of infusion on ketamine efficacy were analyzed statistically. Seven patients (4 males, 3 females; age: 44-86 years) were included in the study. Encephalitis was the most common etiology. Concurrent antiseizure medications varied between 2 and 5. Six patients received midazolam before/during ketamine infusion. Ketamine was initiated 2 to 7 days after the onset of EEG monitoring and lasted 3 to 24 days with a maximum infusion dose ranging between 1 to 5 mg/kg/h. It was definitely effective in 4 patients, and possibly effective in an additional patient. Earlier initiation was correlated with higher efficacy (P = .047). There was a trend toward higher efficacy with longer duration of infusion (P = .285). Overall prognosis was poor with 29% mortality rate. Temporary hepatic failure occurred in 1 patient. Ketamine appears to be a promising drug in r/srNCSE. Earlier and prolonged infusion, as well as combination with benzodiazepines may increase its efficacy. Adverse events are rarely observed.

An uncommon case of nonconvulsive status epilepticus successfully treated with enteral Brivaracetam

BACKGROUND AND AIM OF THE WORK

We present a case of a woman affected by nonconvulsive status epilepticus (NCSE) caused by cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA) who was successfully treated with Brivaracetam (BRV) administered via nasogastric tube (NGT).

CASE PRESENTATION

An 82-years old woman was referred for increasing blood pressure, severe headache and two focal motor seizures on postoperative day four after right CEA. CT scan showed edema of the right hemisphere with a midline shift of 5 mm. The patient underwent daily Electroencephalography (EEG) monitoring which showed continuous epileptiform discharges over the right hemisphere, compatible with a diagnosis of status epilepticus. She was treated with standard antiepileptic drugs (Phenytoin, Lacosamide and Levetiracetam iv) without clinical response. A therapeutic trial with BRV 200mg administered via nasogastric tube (NGT) was tried which resulted in substantial clinical benefit.

CONCLUSIONS

The administration of new antiepileptic drugs (AEDs) such as BRV may result in significant clinical improvement in refractory cases of status epilepticus. The enteral administration of AEDs via NGT should always be considered for refractory cases of status epilepticus when standard iv treatment has failed or is not possible.

Nonconvulsive status epilepticus manifesting as rapidly progressive dementia and infarction in the splenium of the corpus callosum: A case report

RATIONALE

Nonconvulsive status epilepticus (NCSE) is a heterogeneous disease with multiple subtypes. NCSE poses great diagnostic and therapeutic challenges due to the lack of typical symptoms. Here, we report a case of NCSE manifesting as rapidly progressive dementia (RPD) and infarction in the splenium of the corpus callosum. Additionally, the relevant literature was reviewed.

PATIENT CONCERNS

A 63-year-old man presented with RPD. Electroencephalogram (EEG) revealed NCSE, and brain magnetic resonance imaging (MRI) showed an isolated infarction in the splenium of the corpus callosum. Mini-mental state examination showed moderate cognitive impairment (14/30 points).

DIAGNOSIS

A diagnosis of NCSE with RPD and infarction in the splenium of the corpus callosum was made.

INTERVENTIONS

The patient was treated with intravenous diazepam (10 mg), oral levetiracetam (1.0g twice daily), oral sodium valproate (0.2g twice daily), and intramuscular phenobarbital sodium (0.2g once daily).

OUTCOMES

After the treatment, the symptoms were improved. The patient could answer questions. Repeated EEG showed that the background a rhythm was slightly overdeveloped, and no clinical or electrical seizures were observed. After discharge, the patient was treated with oral levetiracetam (1.0g twice daily) and oral sodium valproate (0.2g twice daily) for 6 months. At the last follow-up, the patient had clear consciousness, sensitive response, and fluent answering ability. Repeated mini-mental state examination showed that his cognitive function was significantly improved (28/30 points); nevertheless, the lesion in the splenium of corpus callosum remained unchanged on MRI.

LESSONS

NCSE manifesting as RPD and infarction in the splenium of the corpus callosum is extremely rare. Epileptic events and focal infarction are usually overlooked in patients with dementia, and the diagnostic value of MRI and EEG should be highlighted.

Clinical Characteristics and Treatment Outcomes of De Novo Nonconvulsive Status Epilepticus: A Retrospective Study

Background and Purpose

Nonconvulsive status epilepticus (NCSE) is challenging to diagnose. This study aimed to describe and classify the clinical features and electroencephalography (EEG) findings of patients with de novo NCSE and to correlate them with clinical outcomes.

Methods

We retrospectively reviewed the medical and EEG records of patients admitted to our institution with altered mentation and EEG abnormalities from January 1, 2013 to December 31, 2018. We evaluated premorbid modified Rankin Scale (mRS) scores, underlying disorders, precipitating factors, clinical manifestations, laboratory tests, and outcomes after a 3-month follow-up. Patients who met the Salzburg Consensus Criteria for NCSE were categorized into good-outcome and poor-outcome groups. A good outcome was defined as 1) clinical and electrographic seizures ceasing after treatment, and 2) an mRS score of ≤2 or remaining unchanged during the 3-month follow-up. A poor outcome was defined as 1) death, 2) seizures continuing despite treatment, or 3) a follow-up mRS score of ≥3 in a patient with a premorbid mRS score of ≤2, or a follow-up mRS score that increased in a patient with a premorbid mRS score of ≥3.

Results

The 48 included patients comprised 37 categorized into the good-outcome group and 11 into the poor-outcome group. The presence of acute metabolic disturbances was significantly correlated with poor outcome (p=0.036), while the other analyzed variables were not significantly correlated with outcomes.

Conclusions

Acute metabolic disturbances in NCSE are associated with poor outcomes. Adequate treatment of underlying reversible disorders alongside controlling seizures is critical for patients with NCSE.

Treatments for Convulsive and Nonconvulsive Status Epilepticus in Adults: An Expert Opinion Survey in South Korea

BACKGROUND AND PURPOSE

The aim of this study was to survey the expert opinions on treatments for convulsive status epilepticus (CSE) and nonconvulsive status epilepticus (NCSE) in adults.

METHODS

Forty-two South Korean epileptologists participated in this survey. They completed an online questionnaire regarding various patient scenarios and evaluated the appropriateness of medications used to treat CSE and NCSE.

RESULTS

Initial treatment with a benzodiazepine (BZD) followed by either a second BZD or an antiepileptic drug (AED) monotherapy was the preferred treatment strategy. More than two-thirds of the experts used a second BZD when the first one failed, and consensus was reached for 84.8% of the survey items. The preferred BZD was intravenous (IV) lorazepam for the initial treatment of status epilepticus. IV fosphenytoin and IV levetiracetam were chosen for AED monotherapy after the failure of BZD. The treatments for NCSE were similar to those for CSE. Continuous IV midazolam infusion was the treatment of choice for iatrogenic coma in refractory CSE, but other AEDs were preferred over iatrogenic coma in refractory NCSE.

CONCLUSIONS

The results of this survey are consistent with previous guidelines, and can be cautiously applied in clinical practice when treating patients with CSE or NCSE.

Time to Detection of the First Seizure in Patients With Nonconvulsive Status Epilepticus in the Neurological Intensive Care Unit

Video-EEG monitoring is often used to detect nonconvulsive status epilepticus (NCSE) in critical care patients. Short recording durations may fail to detect seizures. In this study, we investigated the time required to record the first ictal event, and whether it could be correlated with some clinical or EEG parameters. Video-EEG recordings of patients who were followed up in our neurological intensive care unit were evaluated retrospectively. The EEG recordings of patients with NCSE were reviewed to determine the timing of the first seizure occurrence. Demographic data and EEG findings were obtained from patient charts and EEG reports. Possible correlations between the presence of periodic discharges (PD), Glasgow Coma Scale (GCS) score and early seizure detection (defined as a seizure within the first hour of recording) were explored statistically. Out of 200 patients who underwent video-EEG monitoring, we identified 30 cases (15%; 18 male, 12 female; age 24-86 years; mean recording duration 99 hours) with NCSE. The first seizure was recorded within 0 to 1 hour in 22 patients (73%) and within 1 to 12 hours in 6 patients (22%). Interictal PDs were identified in 19 patients (63%). GCS score was ≤8 in 16 patients (53%). There was no correlation between early seizure detection and PDs (p=1.0) or GCS score (P = .22). In our study, >90% of the seizures were captured within 12 hours. This finding suggests that most of the NCSE cases can be identified even in centers with limited resources. The presence or absence of PDs or GCS score does not predict the timing of the first seizure.

Clinical Characteristics and Nonconvulsive Seizures in Young Children With Abusive Head Trauma

AIM

We aimed to evaluate putative predictors of symptoms and signs at admission for nonconvulsive seizure and to examine the impact of nonconvulsive seizures on short-term outcomes.

METHOD

We retrospectively collected consecutive abusive head trauma patients (<36 months of age) from the trauma registry at Children's Healthcare of Atlanta between 2009 and 2014. Multiple logistic regression was performed to assess the putative predictors for the occurrence of nonconvulsive seizures including clinical seizures, altered mental status, respiratory difficulty, and cardiac arrest at admission, while controlling for age, sex, and injury severity. The Mann-Whitney U test and the Fisher exact test were used to compare the short-term outcomes between patients with and without nonconvulsive seizures.

RESULTS

Two hundred seventy patients with abusive head trauma were identified (male = 55.6%). The median age was 4 months (interquartile range = 2-8 months). Among 70 patients who underwent continuous electroencephalography (EEG), 40 had nonconvulsive seizures (57%) and 21 developed nonconvulsive status epilepticus (30%). Altered mental status at admission was associated with the occurrence of nonconvulsive seizures (odds ratio = 6.8, 95% confidence interval = 1.2-38.2, P = .03). Comparing patients with no seizures, those with nonconvulsive seizures were more likely to stay longer at hospital (9 days vs 14 days, P = .04) and to need rehabilitation (50.0% vs 63.2%, P = .03).

CONCLUSIONS

Nonconvulsive seizures and nonconvulsive status epilepticus was highly prevalent in young pediatric patients with abusive head trauma. Presenting with altered mental status at admission was found to predict the occurrence of nonconvulsive seizures. Nonconvulsive seizures had an unfavorable impact on short-term outcomes.

[Fatal Outcome of Agranulocytosis after Re-Exposure to Metamizole and Cefepime-Induced Encephalopathy]

Fatal Outcome of Agranulocytosis after Re-Exposure to Metamizole and Cefepime-Induced Encephalopathy Abstract. We present the case of an 83-year-old female patient who died as a result of likely drug-induced complications, namely agranulocytosis caused by metamizole and cefepime-induced encephalopathy. Agranulocytosis precipitated a cascade of events that eventually led to death. As prescription of metamizole has increased over the past decades, it is important to keep in mind its serious adverse drug reactions. Metamizole must be stopped immediately at the onset of symptoms such as fever, mucositis and sore throat, and re-exposure in patients who have previously developed leukopenia under metamizole must be avoided. This can be achieved by meticulous documentation in the medical records and the use of an emergency or allergy alert card which the patient carries at all times. When using cefepime, renal function should be closely monitored, especially in multimorbid geriatric patients, and the dose should be adjusted accordingly.

Relationship between Status Epilepticus Severity Score and etiology in adult NCSE patients

Background and purpose

Nonconvulsive status epilepticus (NCSE) is a heterogeneous, severe neurological disorder of different etiologies. In this study, the outcomes of NCSE episodes was assessed in a large series of adult patients. Our objective was to evaluate relationship between Status Epilepticus Severity Score (STESS) and etiology and the role of etiological factors on predicting the outcomes.

Methods

In this retrospective study, the medical records of 95 patients over 18 years of age who were diagnosed with NCSE between June 2011 and December 2015 were reviewed. Their treatment and follow-up for NCSE was performed at the Epilepsy Unit in Department of Neurology, Antalya Research and Training Hospital. Etiological factors thought to be responsible for NCSE episodes as well as the prognostic data were retrieved. The etiological factors were classified into three groups as those with a known history of epilepsy (Group 1), primary neurological disorder (Group 2), or systemic/unknown etiology (Group 3). STESS was retrospectively applied to patients.

Results

There were 95 participants, 59 of whom were female. Group 1, Group 2, and Group 3 consisted of 11 (7 female), 54 (33 female), and 30 (19 female) patients, respectively. Of the 18 total deaths, 12 occurred in Group 2, and 6 in Group 3. The negative predictive value for a STESS score of ≤ 2 was 93.88% (+LR 2.05 95% CI: 1.44-2.9 and -LR 0.3 95% CI 0.10-0.84 ) in the overall study group. While the corresponding values for Group 1 (patients with epilepsy), Group 2 (patients with primary neurological disorder), and group 3 (patients with systemic or unknown etiology) were 100%, 92.59% (+LR 2.06 95%CI: 1.32-3.21 and -LR 0.28 95% CI 0.08-1.02 ) 83.33% (+LR 1.14 95%CI: 0.59-2.9 and -LR 0.80 95% CI 0.23-2.73).

Conclusion

This study included the one of the largest patients series ever reported in whom STESS, a clinical scoring system proposed for use in patients with status epilepticus, has been implemented. Although STESS appeared to be quite useful for predicting a favorable outcome in NCSE patients with epilepsy and primary neurological disorders, its predictive value in patients with systemic or unknown etiology was lower. Further prospective studies including larger NCSE samples are warranted.

The difficulty of diagnosing NCSE in clinical practice; external validation of the Salzburg criteria

To improve the diagnostic accuracy of electroencephalography (EEG) criteria for nonconvulsive status epilepticus (NCSE), external validation of the recently proposed Salzburg criteria is paramount. We performed an external, retrospective, diagnostic accuracy study of the Salzburg criteria, using EEG recordings from patients with and without a clinical suspicion of having NCSE. Of the 191 EEG recordings, 12 (12%) was classified as an NCSE according to the reference standard. In the validation cohort, sensitivity was 67% and specificity was 89%. The positive predictive value was 47% and the negative predictive value was 95%. Ten patients in the control group (n = 93) were false positive, resulting in a specificity of 89.2%. The interrater agreement between the reference standards and between the scorers of the Salzburg criteria was moderate; disagreement occurred mainly in patients with an epileptic encephalopathy. The Salzburg criteria showed a lower diagnostic accuracy in our external validation study than in the original design, suggesting that they cannot replace the current practice of careful weighing of both clinical and EEG information on an individual basis.

Epileptiform activity contralateral to unilateral hippocampal sclerosis does not cause the expression of brain damage markers

OBJECTIVE

Patients with epilepsy often ask if recurrent seizures harm their brain and aggravate their epileptic condition. This crucial question has not been specifically addressed by dedicated experiments. We analyze here if intense bilateral seizure activity induced by local injection of kainic acid (KA) in the right hippocampus produces brain damage in the left hippocampus.

METHODS

Adult guinea pigs were bilaterally implanted with hippocampal electrodes for continuous video-electroencephalography (EEG) monitoring. Unilateral injection of 1 μg KA in the dorsal CA1 area induced nonconvulsive status epilepticus (ncSE) characterized by bilateral hippocampal seizure discharges. This treatment resulted in selective unilateral sclerosis of the KA-injected hippocampus. Three days after KA injection, the animals were killed, and the brains were submitted to ex vivo magnetic resonance imaging (MRI) and were processed for immunohistochemical analysis.

RESULTS

During ncSE, epileptiform activity was recorded for 27.6 ± 19.1 hours in both the KA-injected and contralateral hippocampi. Enhanced T1-weighted MR signal due to gadolinium deposition, mean diffusivity reduction, neuronal loss, gliosis, and blood-brain barrier permeability changes was observed exclusively in the KA-injected hippocampus. Despite the presence of a clear unilateral hippocampal sclerosis at the site of KA injection, no structural alterations were detected by MR and immunostaining analysis performed in the hippocampus contralateral to KA injection 3 days and 2 months after ncSE induction. Fluoro-Jade and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining at the same time points confirmed the absence of degenerating cells in the hippocampi contralateral to KA injection.

SIGNIFICANCE

We demonstrate that intense epileptiform activity during ncSE does not cause obvious brain damage in the hippocampus contralateral to unilateral hippocampal KA injection. These findings argue against the hypothesis that epileptiform activity per se contributes to focal brain injury in previously undamaged cortical regions.

Subacute Encephalopathy With Seizures in Alcoholics Syndrome: A Subtype of Nonconvulsive Status Epilepticus

A recent assessment of the classification of nonconvulsive status epilepticus (NCSE) has incorporated the specific electroencephalographic (EEG) patterns on a syndromic basis. Such a clinical EEG syndromic approach may enable more accurate and expedited diagnosis of particular subtypes of NCSE so as to improve therapy. Herein, we review the characteristics of subacute encephalopathy with seizures in alcoholics syndrome, a subtype of focal NCSE occurring in chronic alcoholism with specific features, including encephalopathy, lateralized periodic discharges on the EEG, chronic microvascular ischemia on neuroimaging studies, and possible recurrence when chronic antiseizure treatment is stopped.

Reevaluation of the Critically Ill Patients With Nonconvulsive Status Epilepticus by Using Salzburg Consensus Criteria

OBJECTIVE

We aimed to assess the usefulness of the Salzburg Consensus Criteria (SCC) for determining the prognosis of critically ill patients with nonconvulsive status epilepticus (NCSE).

METHODS

We retrospectively reviewed consecutive patients with unconsciousness followed up in the intensive care unit (ICU). Three clinical neurophysiologists, one of them blinded to clinical and laboratory data, reevaluated all EEG data independently and determined NCSE according to SCC. The incidence of NCSE and ictal EEG patterns and their relationship to clinical, laboratory, neuroradiological, and prognostic findings were assessed.

RESULTS

A total of 107 consecutive patients with mean age 68.2 ± 15.3 years (57 females) were enrolled in the study. Primary neuronal injury was detected in 59 patients (55.7%). Thirty-three patients (30.8%) were diagnosed as NCSE. While authors decided to treat 33 patients (30.8%), 32 patients (29.9%) had been treated in real-life evaluation. Clinical and EEG improvement were detected in 12 patients (11.3%) in real-life treatment group showing correlation with lack of intubation and ICU stay related to postsurgical event. Rate of mortality (45.8%) was high showing association with systemic-metabolic etiology, severity of coma and presence of "plus" modifiers in the EEG.

CONCLUSION AND SIGNIFICANCE

Our findings suggest that SCC is highly compatible with clinical practice in the decision for treatment of patients with NCSE. The presence of "plus" modifiers in the EEG was found to be associated with mortality in these patients and was a significant marker for the high mortality rate.

Cefepime-Induced Encephalopathy and Nonconvulsive Status Epilepticus: Dispelling an Artificial Dichotomy

Cefepime is a fourth-generation cephalosporin antibiotic known to have neurotoxic side effects. Recent reports have described patients on cefepime presenting with altered mentation and concurrent triphasic wave discharges on electroencephalogram (EEG). Some have described this clinical presentation as cefepime-induced encephalopathy, while others have termed it as cefepime-induced nonconvulsive status epilepticus (NCSE). We report on 4 patients who developed cefepime-associated altered mentation with triphasic discharges on EEG. A benzodiazepine trial was attempted in 3 of the patients, all of whom had improvement in the frequency of the triphasic discharges, but only 2 of whom demonstrated a concurrent partial and transient improvement in mental status. All 4 patients had normalization of mental status upon discontinuation of cefepime. We provide a literature review of prior cases and propose that these reports, including those labeled as NCSE, are best described as a cefepime-induced encephalopathy with triphasic discharges as opposed to an ictal phenomenon. We contend that aggressive treatment with anti-seizure medications is not warranted and that cefepime discontinuation is the definitive treatment. This case series and review of the literature clarifies a long-standing terminological ambiguity in a unique clinical picture that can be encountered by the neurohospitalist or other providers.

Status epilepticus in the elderly

Children and the elderly (≥60 years of age) have the highest incidence of status epilepticus (SE). Because of their general health, elderly individuals are much more likely than younger (<60 years of age) persons to have more severe consequences from seizures. The incidence of SE is 15.5/100 000 in the 60-69 age group, 21.5/100 000 in the 70-79 age group and 25.9/100 000 in persons 80 and older. The most common cause in the elderly is acute symptomatic, with stroke and hypoxia the most frequent. The overall mortality of SE is quite high and occurs early, often within the first few days, and is related to the cause, with mortality of more than 80% in persons with anoxia. Although the cause of SE is an important factor in mortality, the aging body and brain may contribute to an unfavorable outcome. Treatment in the elderly is essentially the same as in younger adults with benzodiazepines (lorazepam, diazepam, clonazepam) and longer acting antiseizure drugs (phenytoin, fosphenytoin, valproate, levetiracetam, and lacosamide. At this time there are no evidence-based studies regarding Axis 2 (etiology) and Axis 4 (age). All current interventions for SE involve antiseizure drugs that were developed for treatment of chronic epilepsy. Treatments should be developed that are more specific for the various etiologies and involve drugs that work on the underlying cause of the SE.

Novel TBC1D24 Mutations in a Case of Nonconvulsive Status Epilepticus

Objective: Nonconvulsive status epilepticus (NCSE) is an uncommon clinical manifestation in patients with TBC1D24 mutations. In addition, NCSE has not been reported as a syndrome together with cerebellar ataxia and ophthalmoplegia.

Methods: We herein report the clinical and genetic features of a four-year-old patient with NCSE, cerebellar ataxia, and ophthalmoplegia caused by hitherto unidentified TBC1D24 mutations. We performed 24-h video electroencephalogram (EEG), magnetic resonance imaging, and gene sequencing on the patient and her parents to determine the diagnosis.

Results: We identified a novel c.1416_1437del (p.Ser473Argfs^*43) mutation, as well as the previously identified c.1499C>T (p.Ala500Val) mutation in TBC1D24, by using targeted next-generation sequencing. The novel mutation (inherited from the mother) is the first reported deletion mutation longer than 20 bp in TBC1D24. The p.Ala500Val mutation inherited from father has been reported in a German patient with infantile myoclonic, for whom results from the EEG and neuroimaging were normal. These two mutations resulted in the severe phenotypes observed in our patient

Conclusions: The identification of the novel TBC1D24 mutation and consequent complicated clinical manifestations suggest that patients with NCSE and ataxia demand more attention. We further recommend that genetic test should be administered to these patients to avoid genetic inheritance of this mutation.

Treatment of Refractory and Super-refractory Status Epilepticus

Refractory and super-refractory status epilepticus (SE) are serious illnesses with a high risk of morbidity and even fatality. In the setting of refractory generalized convulsive SE (GCSE), there is ample justification to use continuous infusions of highly sedating medications-usually midazolam, pentobarbital, or propofol. Each of these medications has advantages and disadvantages, and the particulars of their use remain controversial. Continuous EEG monitoring is crucial in guiding the management of these critically ill patients: in diagnosis, in detecting relapse, and in adjusting medications. Forms of SE other than GCSE (and its continuation in a "subtle" or nonconvulsive form) should usually be treated far less aggressively, often with nonsedating anti-seizure drugs (ASDs). Management of "non-classic" NCSE in ICUs is very complicated and controversial, and some cases may require aggressive treatment. One of the largest problems in refractory SE (RSE) treatment is withdrawing coma-inducing drugs, as the prolonged ICU courses they prompt often lead to additional complications. In drug withdrawal after control of convulsive SE, nonsedating ASDs can assist; medical management is crucial; and some brief seizures may have to be tolerated. For the most refractory of cases, immunotherapy, ketamine, ketogenic diet, and focal surgery are among several newer or less standard treatments that can be considered. The morbidity and mortality of RSE is substantial, but many patients survive and even return to normal function, so RSE should be treated promptly and as aggressively as the individual patient and type of SE indicate.

Nonconvulsive status epilepticus in rats leads to brain pathology

OBJECTIVE

Status epilepticus (SE) is an abnormally prolonged epileptic seizure that if associated with convulsive motor symptoms is potentially life threatening for a patient. However, 20%-40% of patients with SE lack convulsive events and instead present with more subtle semiology such as altered consciousness and less motor activity. Today, there is no general consensus regarding to what extent nonconvulsive SE (NCSE) is harmful to the brain, which adds uncertainty to stringent treatment regimes.

METHODS

Here, we evaluated brain pathology in an experimental rat and mouse model of complex partial NCSE originating in the temporal lobes with Western blot analysis, immunohistochemistry, and ex vivo diffusion tensor imaging (DTI). The NCSE was induced by electrical stimulation with intrahippocampal electrodes and terminated with pentobarbital anesthesia. Video-electroencephalographic recordings were performed throughout the experiment.

RESULTS

DTI of mice 7 weeks post-NCSE showed no robust long-lasting changes in fractional anisotropy within the hippocampal epileptic focus. Instead, we found pathophysiological changes developing over time when measuring protein levels and cell counts in extracted brain tissue. At 6 and 24 hours post-NCSE in rats, few changes were observed within the hippocampus and cortical or subcortical structures in Western blot analyses of key components of the cellular immune response and synaptic protein expression, while neurodegeneration had started. However, 1 week post-NCSE, both excitatory and inhibitory synaptic protein levels were decreased in hippocampus, concomitant with an excessive microglial and astrocytic activation. At 4 weeks, a continuous immune response in the hippocampus was accompanied with neuronal loss. Levels of the excitatory synaptic adhesion molecule N-cadherin were decreased specifically in rats that developed unprovoked spontaneous seizures (epileptogenesis) within 1 month following NCSE, compared to rats only exhibiting acute symptomatic seizures within 1 week post-NCSE.

SIGNIFICANCE

These findings provide evidence for a significant brain pathology following NCSE in an experimental rodent model.

Detecting silent seizures by their sound

OBJECTIVE

The traditional approach to interpreting electroencephalograms (EEGs) requires physicians with formal training to visually assess the waveforms. This approach can be less practical in critical settings where a trained EEG specialist is not readily available to review the EEG and diagnose ongoing subclinical seizures, such as nonconvulsive status epilepticus.

METHODS

We have developed a novel method by which EEG data are converted to sound in real time by letting the underlying electrophysiological signal modulate a voice tone that is in the audible range. Here, we explored whether individuals without any prior EEG training could listen to 15-second sonified EEG and determine whether the EEG represents seizures or nonseizure conditions. We selected 84 EEG samples to represent seizures (n = 7), seizure-like activity (n = 25), or nonperiodic, nonrhythmic activity (normal or focal/generalized slowing, n = 52). EEGs from single channels in the left and right hemispheres were then converted to sound files. After a 4-minute training video, medical students (n = 34) and nurses (n = 30) were asked to designate each audio sample as "seizure" or "nonseizure." We then compared their performance with that of EEG-trained neurologists (n = 12) and medical students (n = 29) who also diagnosed the same EEGs on visual display.

RESULTS

Nonexperts listening to single-channel sonified EEGs detected seizures with remarkable sensitivity (students, 98% ± 5%; nurses, 95% ± 14%) compared to experts or nonexperts reviewing the same EEGs on visual display (neurologists, 88% ± 11%; students, 76% ± 19%). If the EEGs contained seizures or seizure-like activity, nonexperts listening to sonified EEGs rated them as seizures with high specificity (students, 85% ± 9%; nurses, 82% ± 12%) compared to experts or nonexperts viewing the EEGs visually (neurologists, 90% ± 7%; students, 65% ± 20%).

SIGNIFICANCE

Our study confirms that individuals without EEG training can detect ongoing seizures or seizure-like rhythmic periodic patterns by listening to sonified EEG. Although sonification of EEG cannot replace the traditional approaches to EEG interpretation, it provides a meaningful triage tool for fast assessment of patients with suspected subclinical seizures.

Can endotracheal intubation be the first step in management of nonconvulsive status epilepticus?: A case report

RATIONALE

Nonconvulsive status epilepticus (NCSE) is prolonged seizure activity without motor manifestations. Clinically, there are certain examination findings, in addition to elements of history, that help differentiate it from other encephalopathies. When diagnosing NCSE, the physician faces significant difficulties due to inconsistent clinical presentation and somewhat nonspecific electroencephalogram (EEG) criteria.

PATIENT CONCERNS

To highlight the problems faced when dealing with such a patient, a case of a 29-year-old male who presented with an altered state of consciousness is put forth for the reader. Only after an extensive laboratory and radiological workup had ruled out other causes, an eventual diagnosis was established when clinical features were correlated with suggestive EEG results.

DIAGNOSES

The diagnosis that was reached was NCSE.

INTERVENTIONS

The initial therapeutic interventions generally deployed in such a scenario ultimately failed and consequently the patient had to be sedated and intubated, while being kept on antiepileptic medication.

OUTCOMES

This measure resulted in satisfactory recovery.

LESSONS

Accordingly, we recommend consideration of NCSE in any unconscious patient whose presentation cannot be explained by other disorders. Furthermore, we suggest moving directly to utilizing anesthetic agents and endotracheal intubation, together with anti-epileptic drugs, in the treatment regimen in order to optimize patient outcomes.

Ceftriaxone-induced Neurotoxicity in a Patient after Pancreas-Kidney Transplantation

Ceftriaxone is a widely used third-generation cephalosporin showing advantageous pharmacokinetic properties and a broad antimicrobial spectrum. We herein report a case of ceftriaxone-induced neurotoxicity in a 56-year-old man on hemodialysis. Seven days after initiating high-dose ceftriaxone, the patient developed impaired consciousness along with facial myoclonus and sporadic phonation. The symptoms clearly disappeared shortly after withdrawal of the drug. Ceftriaxone is considered a safe antibiotic for patients with renal insufficiency, since it is excreted via both haptic and renal pathways. Physicians should note that antibiotic-associated encephalopathy may develop in patients administered ceftriaxone, especially in those complicated with renal dysfunction.

Novel clinical features of nonconvulsive status epilepticus

Nonconvulsive status epilepticus (NCSE) has rapidly expanded from classical features such as staring, repetitive blinking, chewing, swallowing, and automatism to include coma, prolonged apnea, cardiac arrest, dementia, and higher brain dysfunction, which were demonstrated mainly after the 2000s by us and other groups. This review details novel clinical features of NCSE as a manifestation of epilepsy, but one that is underdiagnosed, with the best available evidence. Also, we describe the new concept of epilepsy-related organ dysfunction (Epi-ROD) and a novel electrode and headset which enables prompt electroencephalography.

Serial EEG Monitoring in a Patient With Anti-NMDA Receptor Encephalitis

Electroencephalogram (EEG) abnormalities are very common in anti- N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. Extreme delta brush (EDB) is a distinctive EEG pattern that is can be suggestive of the diagnosis; however, the etiology of the EDB remains unclear. Furthermore, there is question with regard to its ictal or interictal nature. We report a 20-year-old woman with anti-NMDAR encephalitis whose serial video-EEG monitoring was obtained at 2, 2.5, 4, and 6 months after admission. There was a long-standing EDB lasting up to several hours, with no evolution in frequency, amplitude, or morphology, and without clear association her frequent orofacial dyskinesia. Intravenous benzodiazepine administrations did not change the EDB pattern. As her clinical symptoms improved, the EDB gradually became less prominent and less frequent, with complete resolution at 6 months after admission. These findings suggest that EDB is more likely a marker of the severity of the disease in contrast to an epileptic seizure and is useful for diagnosis and monitoring of treatment response in conjunction with clinical improvement.

Seizures in the critically ill

Critically ill patients with seizures are either admitted to the intensive care unit because of uncontrolled seizures requiring aggressive treatment or are admitted for other reasons and develop seizures secondarily. These patients may have multiorgan failure and severe metabolic and electrolyte disarrangements, and may require complex medication regimens and interventions. Seizures can be seen as a result of an acute systemic illness, a primary neurologic pathology, or a medication side-effect and can present in a wide array of symptoms from convulsive activity, subtle twitching, to lethargy. In this population, untreated isolated seizures can quickly escalate to generalized convulsive status epilepticus or, more frequently, nonconvulsive status epileptics, which is associated with a high morbidity and mortality. Status epilepticus (SE) arises from a failure of inhibitory mechanisms and an enhancement of excitatory pathways causing permanent neuronal injury and other systemic sequelae. Carrying a high 30-day mortality rate, SE can be very difficult to treat in this complex setting, and a portion of these patients will become refractory, requiring narcotics and anesthetic medications. The most significant factor in successfully treating status epilepticus is initiating antiepileptic drugs as soon as possible, thus attentiveness and recognition of this disease are critical.

Guiding Antiepileptic Therapy in a Pediatric Patient with Severe Meningoencephalitis and Decompressive Craniectomy with the Use of Amplitude-Integrated Electroencephalography

Introduction Amplitude-integrated electroencephalography (aEEG) is one of the most widely used neuromonitoring tools in neonatology today. However, little is known about its clinical indications and potential benefits in pediatric intensive care patients. Based on limited experience, its impact on therapeutic decision-making in this patient population is unclear. Case Description We report the case of a 16-year-old boy who, after a pansinusitis, developed a severe meningoencephalitis and intracranial empyema with increased intracranial pressure that required drainage and decompressive craniectomy. He subsequently developed status epilepticus despite a combination of various anticonvulsants. Only after the initialization of an aEEG, we were able to adequately diagnose and continuously monitor his seizure activity and titrate the effect of the antiepileptic drugs. During his hospital stay, we were able to clearly monitor and guide our therapy by accurately identifying the termination of status epilepticus and the recurrence of seizures. Discussion With the help of aEEG, it was easy to identify the nonconvulsive status epilepticus (NCSE) and the ongoing seizure activity in this teenage patient. NCSE is a clinical problem with an effect on the outcome of the patient and is often underdiagnosed. AEEG enabled a rapid detection and management of seizure activity and thereby reduced the overall seizure burden, which was associated with better neurologic outcome.

Are There Any Specific EEG Findings in Autoimmune Epilepsies?

This study evaluated the EEG findings of patients whose seizures were associated with a possible autoimmune etiology. Our aim was to find clues to distinguish patients with antineuronal antibodies (Ab) through EEG studies. We reviewed our database and identified antineuronal Ab positive epilepsy patients with or without autoimmune encephalitis. These patients had Abs to N-methyl-d-aspartate receptor (NMDAR) (n = 5), glycine receptor (GLY-R) (n = 5), contactin-associated protein-like 2 (CASPR-2) (n = 4), uncharacterized voltage-gated potassium channel complex (VGKC) antigens (n = 2), glutamic acid decarboxylase (GAD) (n = 2), Hu (n = 1), and amphiphysin (n = 1). The control group consisted of 21 seronegative epilepsy or encephalopathy patients with similar clinical features. EEG findings were compared between the groups in a blindfolded design. We did not find any significant difference in EEG findings between antineuronal Ab positive epilepsy patients and seronegative control group. It was remarkable that four seropositive but none of the seronegative patients presented with nonconvulsive status epilepticus (NCSE) or focal motor status epilepticus. Continuous theta and delta rhythms were observed in 5 (71%) seropositive patients with autoimmune encephalitis and 2 (25%) seronegative patients. Eight (40 %) seropositive patients showed a frontal intermittent rhythmic delta activity (FIRDA) pattern as opposed to 5 (24%) seronegative patients. Two patients with NMDAR Ab positivity showed rhythmic delta waves superimposed with beta frequency activity resembling "delta brush" pattern. EEG seems as a limited diagnostic tool in differentiating epilepsy and/or encephalopathy patients with a possible autoimmune etiology from those without. However, antineuronal Abs associated with encephalitis should be considered in the etiology of status epilepticus forms. A possible autoimmune etiology for seizures may be considered in the presence of continuous slow waves, FIRDA, and delta brush pattern in the EEG.

StatNet Electroencephalogram: A Fast and Reliable Option to Diagnose Nonconvulsive Status Epilepticus in Emergency Setting

BACKGROUND

The StatNet electrode set is a system that can be applied by a non-electroencephalogram (EEG) technologist after minimal training. The primary objectives of this study are to assess the quality and reliability of the StatNet recordings in comparison to the conventional EEG.

METHODS

Over 10 months, 19 patients with suspected nonconvulsive status epilepticus were included from university hospital emergency settings. Each patient received a StatNet EEG by a trained epilepsy fellow and a conventional EEG by registered technologists. We compared the studies in a blinded fashion, for the timeframe from EEG order to the setup time, start of acquisition, amount of artifact, and detection of abnormalities. The nonparametric Mann-Whitney two-sample t test was used for comparisons. The kappa score was used to assess reliability.

RESULTS

Mean age of patients was 61±16.3 (25-93) years. The inter-observer agreement for detection of abnormal findings was 0.83 for StatNet and 0.75 for conventional EEG. Nonconvulsive status epilepticus was detected in 10% (2/19) in both studies. The delay from the time of EEG requisition to acquisition was shorter in the StatNet (22.4±2.5 minutes) than the conventional EEG (217.7±44.6 minutes; p<0.0001). The setup time was also shorter in the StatNet (9.9±0.8 minutes) compared with the conventional EEG (17.8±0.8 minutes; p<0.0001). There was no difference in the percentage of artifact duration between the two studies (p=0.89).

CONCLUSION

This study demonstrates that StatNet EEG is a practical and reliable tool in the emergency setting, which reduces the delay of testing compared with conventional EEG, without significant compromise of study quality.

Epileptic Ictal Hyperperfusion on Arterial Spin Labeling Perfusion and Diffusion-Weighted Magnetic Resonance Images in Posterior Reversible Encephalopathy Syndrome

BACKGROUND

The hemodynamic state of the posterior dominant vasogenic edema in posterior reversible encephalopathy syndrome (PRES) is controversial. The aim of this retrospective study was to examine the contribution of epileptic ictal hyperperfusion in patients with PRES using combined magnetic resonance perfusion imaging with arterial spin labeling (ASL) and diffusion-weighted magnetic resonance imaging (MRI).

METHODS

A detailed review of chronological MRI findings in 2 patients, including diffusion-weighted imaging (DWI) and ASL, with special reference to clinical and electroencephalographic findings, was performed. At the onset of PRES, both patients developed secondary generalized seizures.

RESULTS

At the first PRES episode in Case 1, ASL and DWI clearly depicted "ictal hyperperfusion" and prolonged epilepsy-induced cytotoxic edema in the left parieto-occipital lobe cortex, located around the vasogenic edema of the PRES lesion in the left occipital lobe (hypoperfused area). At the second and third episodes (2 and 7 months after the first episode, respectively), although recurrent PRES was ruled out, ASL and DWI clearly demonstrated ictal hyperperfusion in the left posterior temporal and parieto-occipital lobes associated with partial nonconvulsive status epilepticus, which developed around the PRES-related old hematoma lesion. In Case 2, peri-ictal MRI findings of ictal ASL hyperperfusion and cortical hyperintensity on DWI were also noted in the left parieto-occipital lobe, but were mild compared with Case 1.

CONCLUSIONS

Combined use of DWI and ASL can provide information on hemodynamic state associated with epileptic ictal hyperperfusion in the various phases of PRES.

Nonconvulsive seizures and status epilepticus in pediatric head trauma: A national survey

OBJECTIVES

It remains uncertain whether nonconvulsive seizures and nonconvulsive status epilepticus in pediatric traumatic brain injury are deleterious to the brain and/or impact the recovery from injury. Consequently, optimal electroencephalographic surveillance and management is unknown. We aimed to determine specialists' opinion regarding the detection and treatment of nonconvulsive seizures or nonconvulsive status epilepticus in pediatric traumatic brain injury, regardless of their practice.

METHODS

In 2012, 183 surveys were sent to all 93 neurologists, 27 neurosurgeons, and 63 intensivists in the14 tertiary pediatric hospitals across Canada. The survey included an initial scenario of pediatric TBI that evolved into three further scenarios. Each scenario had required responses and an embedded branching logic algorithm ascertaining clinical management. The survey instrument assimilated data about the importance of nonconvulsive status epilepticus and nonconvulsive seizures detection and treatment, and whether they are a cause of brain injury that adversely affects neurologic outcomes.

RESULTS

Of the 79 specialists who replied (43% response rate), 68%-78% elected to order an electroencephalographic across all four scenarios, and one-third (31%-36%; scenario dependent) would request an urgent electroencephalographic (within the hour) in the comatose pediatric traumatic brain injury patient. In the absence of pharmacologic paralysis or intracranial pressure spikes, half-hour electroencephalographic (41%-55%) was preferred over ⩾24-h continuous electroencephalographic monitoring (29%-40%). Finally, nonconvulsive status epilepticus (81%-87%) and nonconvulsive seizures (61%-73%) were considered to be a cause of poor neurologic outcomes warranting aggressive pharmacologic management.

CONCLUSION

The Canadian specialists' opinion is that nonconvulsive seizures and nonconvulsive status epilepticus are biomarkers of brain injury and contribute to worsened outcomes. This suggests the urgency of future outcome-oriented research in the identification and management of nonconvulsive seizures or nonconvulsive status epilepticus.

Nonconvulsive partial status epilepticus mimicking recurrent infarction revealed by diffusion-weighted and arterial spin labeling perfusion magnetic resonance images

"Non-convulsive" partial status epilepticus (SE) is an important pathologic condition that should be differentiated from cerebral infarction. Herein, we reported 2 patients who had partial SE associated with old infarction in the right parietal lobe. Each patient had 2 episodes of left hemiparesis and hemisensory disturbance without convulsion. On diffusion-weighted magnetic resonance images (DW-MRI), a hyperintense lesion was noted in the cortex around the old infarction lesion, and recurrent infarction was suspected. Although electroencephalography (EEG) failed to reveal ictal discharges or interictal paroxysmal activities in 3 of 4 episodes, perfusion images with arterial spin labeling (ASL) clearly demonstrated ictal hyperperfusion in the area corresponding to the cortical hyperintense lesion on DW-MRI. After appropriate anticonvulsant treatment based on the diagnosis of partial SE, clinical symptoms were completely improved. These data stress the importance of cortical hyperintensity on DW-MRI and ictal ASL hyperperfusion, even when SE cannot be determined from EEG.

The Clinical Features and Prognosis of Patients With Nonconvulsive Status Epilepticus in the Neurological Intensive Care Unit of a Tertiary Referral Center in Turkey

The availability of video electroencephalography monitoring (VEEGM) in neurological intensive care units has allowed the recognition and treatment of nonconvulsive status epilepticus (NCSE). However, little is known about characteristics, management, and outcomes in patients with NCSE in developing countries. We retrospectively reviewed the video-EEG reports of 120 patients who were monitored from November 2009 to March 2013. Indications for video-EEG were mostly unexplained alterations of consciousness or witnessed convulsive seizures. We identified the clinical characteristics, treatment regimes, and outcomes of patients with NCSE and tried to determine which parameters were associated with prognosis. NCSE was detected in 12/120 (10%) patients (3 females, 9 males; age 24-86 years). Admission diagnoses were: stroke (3), epilepsy (3), autoimmune limbic encephalitis (3), herpes encephalitis (1), presumed encephalitis-cardiac arrest (1), and malignancy (1). Eight patients had witnessed convulsive seizures before video-EEG. Interictal periodic epileptiform discharges were detected in 9 patients. In one-third of patients, ≥2 EEG recordings were required to capture seizures. In addition to anticonvulsants, 3 patients received immunosuppressive therapy, while intravenous anesthetics were given to 7 patients. Four patients (33.3%; 1 female, 3 males; age 51-67 years; etiology: stroke, autoimmune encephalitis, encephalitis-cardiac arrest, and malignancy; Glasgow coma scale (GCS) score <8 in 3 patients; all had periodic discharges; intravenous anesthetics were used) died in the intensive care unit. NCSE is not an infrequent finding in neurological intensive care units, thus necessitating prolonged video-EEG monitoring in patients at risk. Witnessed convulsions may indicate the presence of nonconvulsive seizures in patients with altered consciousness. Repeated recordings may increase the detection of ictal events. Periodic epileptiform discharges are commonly observed and may predict poor prognosis. Mortality seems to be influenced mostly by the underlying etiology.

Nonconvulsive status with metronidazole

OBJECTIVE

To expand the adverse events associated with metronidazole to include nonconvulsive status epilepticus (NCSE).

DESIGN

Observational single case report of a rare association.

SETTING

Hospitalized lung transplant recipient treated with metronidazole for prevention of infection.

PATIENT

A 56-year-old man with systemic symptoms, peripheral neuropathy, generalized seizure, and a subsequent acute deterioration of mental status due to NCSE.

INTERVENTIONS

Administration of midazolam was successful in terminating status epilepticus.

MAIN OUTCOME MEASURES

Abrupt termination of NCSE was evident on continuous bedside electroencephalogam associated with clinical resolution of mental status.

RESULTS

Recovery occurred from NCSE eventually deteriorating to a fatal outcome.

CONCLUSIONS

Metronidazole may be associated with successfully treated NCSE.