Status Triphasicus Versus Status Epilepticus?

Electroencephalographic patterns in unresponsive pediatric patients

WS1.11. EEG in the ICU: Status Epilepticus and the Ictal-Interictal Continuum

Cephalosporin-related neurotoxicity: Metabolic encephalopathy or non-convulsive status epilepticus?

IntroductionNonconvulsive seizures (NCS) are frequent in hospitalized patients and may further aggravate injury in the already damaged brain, potentially worsening outcomes in encephalopathic patients. Therefore, both early seizure recognition and treatment have been advocated to prevent further neurological damage.ObjectiveEvaluate the main EEG patterns seen in patients with impaired consciousness and address the effect of treatment with antiepileptic drugs (AEDs), continuous intravenous anesthetic drugs (IVADs), or the combination of both, on outcomes.MethodsThis was a single center retrospective cohort study conducted in a private, tertiary care hospital. Consecutive adult patients with altered consciousness submitted to a routine EEG between January 2008 and February 2011 were included in this study. Based on EEG pattern, patients were assigned to one of three groups: Group Interictal Patterns (IP; EEG showing only interictal epileptiform discharges or triphasic waves), Group Rhythmic and Periodic Patterns (RPP; at least one EEG with rhythmic or periodic patterns), and Group Ictal (Ictal; at least one EEG showing ictal pattern). Groups were compared in terms of administered antiepileptic treatment and frequency of unfavorable outcomes (modified Rankin scale ≥3 and in-hospital mortality).ResultsTwo hundred and six patients (475 EEGs) were included in this analysis. Interictal pattern was observed in 35.4% (73/206) of patients, RPP in 53.4% (110/206) and ictal in 11.2% (23/206) of patients. Treatment with AEDs, IVADs or a combination of both was administered in half of the patients. While all Ictal group patients received treatment (AEDs or IVADs), only 24/73 (32.9%) IP group patients and 55/108 (50.9%) RPP group patients were treated (p<0.001). Hospital length of stay (LOS) and frequency of unfavorable outcomes did not differ among the groups. In-hospital mortality was higher in IVADs treated RPP patients compared to AEDs treated RPP patients [11/19 (57.9%) vs. 11/36 (30.6%) patients, respectively, p = 0.049]. Hospital LOS, in-hospital mortality and frequency of unfavorable outcomes did not differ between Ictal patients treated exclusively with AEDs or IVADs.ConclusionIn patients with acute altered consciousness and abnormal routine EEG, antiepileptic treatment did not improve outcomes regardless of the presence of periodic, rhythmic or ictal EEG patterns.

Postictal deficits are a well-recognized phenomenon, yet their mechanisms and predictors remain poorly understood. Distinguishing postictal deficits from recurring nonconvulsive seizures (NCSz) or nonconvulsive status epilepticus (NCSE), their main differential diagnosis, can be challenging. This study aimed to identify clinical and electrographic features predictive of ongoing or recurrent ictal activity and to explore biomarkers associated with the duration and severity of postictal deficits. We conducted a retrospective case-control study of patients with prolonged (>1 h) postictal deficits at a tertiary medical center between 2017 and 2022. Based on electroencephalographic (EEG) findings, patients were classified as having uncomplicated Todd's palsy or recurring NCSz. Clinical, imaging, and electrographic characteristics were compared between groups, and factors associated with postictal duration were analyzed. Among 112 patients, 86 (77%) had uncomplicated Todd's palsy and 26 (23%) had recurring NCSz. Patients with NCSz were younger (63 vs. 76 years, p = .022) and had longer deficits (2.5 vs. 1.5 days, p = .024). Sporadic epileptiform discharges (73% vs. 22%, p < .001) and rhythmic or periodic discharges on the ictal-interictal continuum (50% vs. 16%, p = .001) were significantly more frequent in the NCSE group, even when limited to short EEGs or the first 30 min of continuous EEG (96% vs. 40%, p < .001). Consequently, 2HELPS2B scores were higher in NCSE patients (2 vs. 1, p = .0065). In the uncomplicated Todd's palsy group, a preceding focal to bilateral tonic-clonic seizure (1.5 vs. 1.0 days, p = .04) and any rhythmic or periodic discharges on EEG (3.0 vs. 1.5 days, p = .003) were associated with longer deficit duration. A notable minority of patients with prolonged postictal deficits have recurring NCSz. In the absence of reliable clinical or imaging predictors, patients with prolonged deficits may benefit from a 30-min EEG followed-when 2HELPS2B score > 1-by extended continuous EEG monitoring.

To quantify the effect of inhaled 5% carbon-dioxide/95% oxygen on EEG recordings from patients in non-convulsive status epilepticus (NCSE). Five children of mixed aetiology in NCSE were given high flow of inhaled carbogen (5% carbon dioxide/95% oxygen) using a face mask for maximum 120s. EEG was recorded concurrently in all patients. The effects of inhaled carbogen on patient EEG recordings were investigated using band-power, functional connectivity and graph theory measures. Carbogen effect was quantified by measuring effect size (Cohen's d) between "before", "during" and "after" carbogen delivery states. Carbogen's apparent effect on EEG band-power and network metrics across all patients for "before-during" and "before-after" inhalation comparisons was inconsistent across the five patients. The changes in different measures suggest a potentially non-homogeneous effect of carbogen on the patients' EEG. Different aetiology and duration of the inhalation may underlie these non-homogeneous effects. Tuning the carbogen parameters (such as ratio between CO2 and O2, duration of inhalation) on a personalised basis may improve seizure suppression in future.

Altered mental state and nonconvulsive status epilepticus in patients with cancer.

Should we treat patients with impaired consciousness and periodic patterns on EEG?

The diagnosis of nonconvulsive status epilepticus (NCSE) relies largely on electroencephalography (EEG) findings. The lack of a unified EEG terminology, and of evidence-based EEG criteria, leads to varying criteria for and ability to diagnose NCSE. We propose a unified terminology and classification system for NCSE, using, as a template, the Standardised Computer-based Organised Reporting of EEG (SCORE). This approach integrates the terminology recently proposed for the rhythmic and periodic patterns in critically ill patients, the electroclinical classification of NCSE (type of NCSE) and the context for the pathologic conditions and age-related epilepsy syndromes. We propose flexible EEG criteria that employ the SCORE system to assemble a database for determining evidence-based EEG criteria for NCSE.

Non-convulsive status epilepticus in a patient with hypocalcemia

Nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) are frequently observed in human patients. Diagnosis of NCS and NCSE only can be achieved by the use of electroencephalography (EEG). Electroencephalographic monitoring is rare in veterinary medicine and consequently there is limited data on frequency of NCS and NCSE. Determine the prevalence of NCS and NCSE in dogs and cats with a history of cluster seizures. Twenty-six dogs and 12 cats. Retrospective study. Medical records of dogs and cats with cluster seizures were reviewed. Electroencephalography was performed in order to identify electrographic seizure activity after the apparent cessation of convulsive seizure activity. Nonconvulsive seizures were detected in 9 dogs and 2 cats out of the 38 patients (29%). Nonconvulsive status epilepticus was detected in 4 dogs and 2 cats (16%). Five patients had both NCS and NCSE. A decreased level of consciousness was evident in 6/11 patients with NCS, 3/6 also had NCSE. Mortality rate for patients with NCS (73%) and NCSE (67%) was much higher than that for patients with no seizure activity on EEG (27%). Prevalence of NCS and NCSE is high in dogs and cats with a history of cluster seizures. Nonconvulsive seizures and NCSE are difficult to detect clinically and are associated with higher in hospital mortality rates. Results indicate that prompt EEG monitoring should be performed in dogs and cats with cluster seizures.

Utility of CT perfusion in seizures and rhythmic and periodic patterns

Electrolytes Disturbances and Seizures

Twenty-six (41%) of 63 consecutive patients with triphasic waves had various types of metabolic encephalopathies while 37 patients (59%) had non-metabolic encephalopathies, usually senile dementia. Triphasic waves were not found to be specific for any single type of metabolic encephalopathy. Etiology was more closely linked to conscious level at recording than any morphological or distributional feature of the triphasic waves themselves. Thus, all 31 alert patients had non-metabolic encephalopathies while all 13 comatose patients had metabolic encephalopathies. The second, positive, component (Wave II) most often had the highest voltage while equally maximal Waves I and II occurred next most commonly. Triphasic waves were most often maximally expressed anteriorly. Among patients with metabolic encephalopathies, a posterior-anterior delay or lag of the wave II peak occurred more commonly than did the better known anterior-posterior lag. Lags occurred with both metabolic and non-metabolic conditions, but were more common with the former. No difference in quantity or mode of appearance existed between the metabolic and non-metabolic groups when matched for conscious level. Prognosis for patients with either metabolic or non-metabolic encephalopathies was unfavourable. Only 4 of 24 metabolic and one of 35 non-metabolic patients were well at follow-up over 2 years later. Forty percent of EEGs with sharp and slow wave complexes (slow spike waves) had sporadically-appearing triphasic waves. The relative amplitudes of the 3 components differed from triphasic waves in other conditions: equally maximal Waves II and III were the most usual form.

Background: The practice of continuous EEG monitoring (CEEG) in the intensive care unit (ICU) has been spreading over the past decade. Building an effective ICU CEEG program with sufficient quality demands adequate EEG equipment and significant human resources. While this is available in large tertiary care centers where the practice of CEEG has developed, it may not be available in developing healthcare systems. This study sought to provide data generated from a CEEG program in the adult ICU at a tertiary healthcare center in Saudi Arabia, shedding light on the real-life utility of CEEG in a developing healthcare system. Methods: This is a retrospective review of CEEG findings, along with mortality and duration of hospitalization of patients who had CEEG during a 12-month period at the adult ICU at the King Abdulaziz University Hospital (KAUH) in Jeddah, Saudi Arabia. Results: A total of 202 CEEG records were identified. A total of 52 patients had non-convulsive seizures (NCS); 10 clearly fulfilled criteria for non-convulsive status epilepticus. There were 120 patients that had clinical seizures upon presentation. Among them, 36 (30%) had NCS on EEG. The proportion of patients who were deceased at 60 days was higher in patients who had NCS (42%) than those who didn't (26%, χ 2 (2, n=200)= 4.4, p=0.03). The duration of hospital stay was longer for those who had periodic or rhythmic CEEG patterns (χ 2 (2, n=200)= 7.6, p=0.02) but there was no significant relationship with mortality at 60 days. Conclusion: This study demonstrates a real-world experience from a tertiary care center in Saudi Arabia, a developing healthcare system. Findings are consistent with prior experience with ICU CEEG, demonstrating that finding ictal, rhythmic or periodic patterns is associated with morbidity and mortality. Further studies are needed to demonstrate how the practice of CEEG may alter patient outcomes.