Nonconvulsive Status Epilepticus in the Neurosurgical Setting

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.

The Past, Present, and Future of Tele-EEG

Tele-electroencephalogram (EEG) has become more pervasive over the last 20 years due to advances in technology, both independent of and driven by personnel shortages. The professionalization of EEG services has both limited growth and controlled the quality of tele-EEG. Growing data on the conditions that benefit from brain monitoring have informed increased critical care EEG and ambulatory EEG utilization. Guidelines that marshal responsible use of still-limited resources and changes in broadband and billing practices have also shaped the tele-EEG landscape. It is helpful to characterize the drivers of tele-EEG to navigate barriers to sustainable growth and to build dynamic systems that anticipate challenges in any of the domains that expand access and enhance quality of these diagnostic services. We explore the historical factors and current trends in tele-EEG in the United States in this review.

Epilepsy in prolonged disorders of consciousness: a systematic review

To date, no guideline exists for the management of epilepsy in patients with prolonged Disorders of Consciousness (DoC). This review aimed to assess the occurrence of epilepsy and epileptic abnormalities (EA) in these patients, to determine their impact on recovery; and to review the effect of antiepileptic drugs (AED) and therapeutic interventions on seizure occurrence and consciousness recovery. A structured search for studies on prolonged DoC and epilepsy was undertaken following PRISMA guidelines. From an initial search resulting in 5,775 titles, twelve studies met inclusion criteria. The occurrence of epilepsy and EA in DoC was poorly and inconsistently reported across studies. The results estimated a seizure prevalence of 27% in DoC. No conclusive data were found for the effects of AED on recovery nor on the influence of any therapeutic interventions on seizure occurrence. Given the scarcity of data, it is premature to make evidence-based recommendations on epilepsy in prolonged DoC. Based on this review and current clinical practices the following are recommended: (1) repeated standard EEG for detecting seizures and EA; (2) treating epilepsy while avoiding AEDs with sedating or cognitive side-effects. Future research should use standardized classification systems for seizures and EA.

Postinfectious inflammation in cerebrospinal fluid is associated with nonconvulsive seizures in subarachnoid hemorrhage patients

PURPOSE

It was unclear how nonconvulsive seizures (NCS) occurred after subarachnoid hemorrhage (SAH). The aim of this prospective observational study was to determine the association between cerebrospinal fluid postinfectious inflammation and NCS in patients with SAH.

METHODS

Demographics and parameters were retrieved from pooled data of all SAH patients monitored by continuous electroencephalography (cEEG) in our Stroke-Intensive Care Unit (Stroke-ICU) over six years period. Patients were divided into two groups (NCS group and non-NCS group). According to clinical and cerebrospinal fluid (CSF) parameters, a logistic regression model was used to analyze the association between CSF inflammation and NCS.

RESULTS

The data of 143 SAH patients were analyzed (25 patients with NCS and 118 patients with non-NCS). Median age was 53 years (min - max: 19 years - 90 years). 4.8 % SAH patients were accompanied with NCS. Among these 25 NCS patients, only 2 (8%) had complete control of EEG discharges. After confounders correction, logistic regression analysis showed: SAH patients with older age [P = 0.003, OR = 1.193, 95 %CI (1.062-1.341)], intracranial infections [P = 0.000, OR = 171.939, 95 %CI (18.136-1630.064)] and higher increased modified Fisher Scale (mFS) [P = 0.003, OR = 8.884, 95 %CI (2.125-37.148)] were more likely to develop NCS; furthermore, a high level of CSF interleukin-6 (IL-6) was an independent risk factor for NCS [P = 0.000, OR = 1.015, 95 %CI (1.010-1.020)], with a threshold of 164.9 pg/mL (sensitivity = 0.84, specificity = 0.96). Compared with non-NCS patients, NCS patients were more likely to have poor Glasgow outcome scale (GOS) (1-3) at 3 months after discharge (88 %).

CONCLUSIONS

SAH patients with NCS were associated with poor neurological prognosis. With the increase of age and mFS, these patients were more likely to develop NCS. As an intracranial infective mark, a high level of CSF IL-6 was an independent risk factor for NCS. For brain protection of severe brain injury after SAH, we should focus on the increasingly important role of inflammatory response.

Nonconvulsive status epilepticus after surgery for ruptured intracranial aneurysms: Incidence, associated factors, and impact on the outcome

OBJECTIVE

To evaluate the incidence of nonconvulsive status epilepticus (NCSE) after surgery for ruptured intracranial aneurysms, to define factors associated with this complication, and to determine its impact on the outcome.

PATIENTS AND METHODS

Clinical and neurophysiological data of 66 patients with aneurysmal subarachnoid hemorrhage (aSAH) who underwent continuous EEG (cEEG) monitoring after microsurgical clipping (53 cases) or endovascular coiling (13 cases) of the ruptured aneurysm were analyzed retrospectively. The diagnosis of NCSE was based on the American Clinical Neurophysiology Society and Salzburg Consensus criteria.

RESULTS

NCSE was revealed in 10 patients (15 %), all of whom underwent craniotomy and aneurysm clipping. In comparison to the subgroup without NCSE, among those who were diagnosed with this complication there was a significantly greater proportion of men (70 % vs. 34 %; P = 0.041), cases with the Glasgow Coma Scale score at admission < 13 (90 % vs. 36 %; P = 0.004), the Hunt and Hess aSAH grades 3-5 (90 % vs. 45 %; P = 0.013), and hydrocephalus (70 % vs. 29 %; P = 0.044). In addition, they required a significantly longer hospital stay (medians, 62.5 vs. 39.5 days; P = 0.015) and showed trend for the lower rate of favorable disability outcomes (20 % vs. 54 %; P = 0.084).

CONCLUSIONS

NCSE is encountered rather often after the microsurgical clipping of ruptured intracranial aneurysms, especially in severely disabled patients with high-grade aSAH and/or associated hydrocpephalus, and may significantly affect the clinical course and prolong recovery. cEEG monitoring may be helpful for timely diagnosis and treatment of this complication.

Dealing with the storm: An overview of seizure precipitants and spontaneous seizure worsening in drug-resistant epilepsy

In drug-resistant epilepsy, periods of seizure stability may alternate with abrupt worsening, with frequent seizures limiting the individual's independence and physical, social, and psychological well-being. Here, we review the literature focusing on different clinical scenarios related to seizure aggravation in people with drug-resistant epilepsy. The role of antiseizure medication (ASM) changes is examined, especially focusing on paradoxical seizure aggravation after increased treatment. The external provocative factors that unbalance the brittle equilibrium of seizure control are reviewed, distinguishing between unspecific triggering factors, specific precipitants, and 'reflex' mechanisms. The chance of intervening surgical or medical conditions, including somatic comorbidities and epilepsy surgery failure, causing increased seizures is discussed. Spontaneous exacerbation is also explored, emphasizing recent findings on subject-specific circadian and ultradian rhythms. Awareness of external precipitants and understanding the subject-specific spontaneous epilepsy course may allow individuals to modify their lifestyles. It also allows clinicians to counsel appropriately and to institute suitable medical treatment to avoid sudden loss of seizure control.

Ictal vomiting after cerebellar hemorrhage: A case report

Vomiting is a typical symptom of cerebellar hemorrhage. Usually only supportive care such as antiemetic drugs are available. A 76-year-old woman presented in a light coma. A head CT demonstrated right cerebellar hemorrhage and the hematoma was surgically evacuated. Her intractable vomiting started 3 weeks after surgery. Because her vomiting was unexplained, we checked her EEG, which demonstrated generalized periodic discharges. We diagnosed her with ictal vomiting. Anti-seizure medication was administered and vomiting was rapidly controlled. In conclusion, physicians must be aware that vomiting may rarely occur as a sign of seizures and status epilepticus.

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Ictal vomiting is one of the clinical presentations of status epilepticus.

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Cerebellar hemorrhage is also cause of ictal vomiting.

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EEG demonstrates periodic discharges.

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Adequate antiepileptic drug may ameliorate ictal vomiting.

Nonconvulsive Status Epilepticus in Acute Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Patients with acute intracerebral hemorrhages (ICHs) often develop nonconvulsive status epilepticus (NCSE). We aimed to identify determinants and the prognostic significance of NCSE among patients with acute ICH.

METHODS

Consecutive patients with acute spontaneous ICH who were admitted to a comprehensive stroke center were enrolled. We diagnosed NCSE using the modified Salzburg Consensus Criteria. Factors associated with NCSE and their significance in relation to clinical outcomes were assessed using multivariate logistic regression models.

RESULTS

Of 228 patients (136 men; mean age, 68±14 years), 20 (8.8%) developed NCSE during their hospital stays. In logistic regression models, the adjusted odds ratios (95% confidence intervals) for NCSE were 3.5 (1.2-10.7) for craniotomy and 7.0 (2.2-31.2) for lobar involvement. The patients with NCSE had higher modified Rankin Scale scores at discharge, but NCSE was not independently associated with poor functional outcomes (modified Rankin Scale score, 4-5) or mortality after adjusting for confounders.

CONCLUSIONS

NCSE is not a rare complication of acute ICH. Craniotomy and lobar involvement are independently associated with NCSE in patients with acute ICH.

No Awakening in Supratentorial Intracerebral Hemorrhage Is Potentially Caused by Sepsis-Associated Encephalopathy

BACKGROUND Acute supratentorial intracerebral hemorrhage (sICH) with secondary sepsis is increasing in frequency. We investigated whether no awakening (NA) after sICH with coma is potentially caused by sepsis-associated encephalopathy (SAE). MATERIAL AND METHODS A case-control study of 147 recruited sICH cases with NA and 198 sICH controls with subsequent awakening (SA) was performed at 2 centers in China. All patients underwent brain computed tomography (CT) scans on admission. The odds ratio (OR) of NA was calculated using logistic regression. RESULTS During the study period, 56.5% (83/147) of the patients with sICH with coma and NA had SAE, and 10% (20/198) with sICH with coma and SA had SAE; this difference between the 2 groups was significant (p<0.000). The sICH patients with coma and NA exhibited a longer median time from onset to coma (2.0 days vs. 0.5 days), more frequent confirmed infection (98.0% vs. 24.2%), and a higher Sequential Organ Failure Assessment (SOFA) score (6.3±1.5 vs. 3.4±0.8). These patients also exhibited lower hematoma volume (28.0±18.8 vs. 38.3±24), a lower initial National Institutes of Health Stroke Scale score (19.5±6.6 vs. 30.3±6.8), more frequent brain midline shift (59.2% vs. 27.8%), more frequent diffuse cerebral swelling (64.6% vs. 16.0%), and higher 30-day mortality (54.4% vs. 0.0%) than the patients who did awaken. Logistic multivariable regression analyses revealed that only a higher SOFA score (OR, 1.4; 95% CI, 1.079-1.767; p=0.010) and SAE (OR, 4.0; 95% CI, 1.359-6.775; p=0.001) were associated with NA events in patients with sICH. CONCLUSIONS NA in sICH patients with coma is potentially caused by secondary SAE.