Status epilepticus in older patients: epidemiology and treatment options

EEG and acute confusional state at the emergency department

OBJECTIVES

Acute confusional state (ACS) is a common cause of admission to the emergency department (ED). It can be related to numerous etiologies. Electroencephalography (EEG) can show specific abnormalities in cases of non-convulsive status epilepticus (NCSE), or metabolic or toxic encephalopathy. However, up to 80% of patients with a final diagnosis of NCSE have an ACS initially attributed to another cause. The exact place of EEG in the diagnostic work-up remains unclear.

METHODS

Data of consecutive patients admitted to the ED for an ACS in a two-year period and who were referred for an EEG were collected. The initial working diagnosis was based on medical history, clinical, biological and imaging investigations allowing classification into four diagnostic categories. Comparison to the final diagnosis was performed after EEG recordings (and sometimes additional tests) were performed, which allowed the reclassification of some patients from one category to another.

RESULTS

Seventy-five patients (mean age: 71.1 years) were included with the following suspected diagnoses: seizures for 8 (11%), encephalopathy for 14 (19%), other cause for 34 (45%) and unknown for 19 (25%). EEG was recorded after a mean of 1.5 days after symptom onset, and resulted in the reclassification of patients as follows: seizure for 15 (20%), encephalopathy for 15 (20%), other cause for 29 (39%) and unknown cause for 16 (21%). Moreover, ongoing epileptic activity (NCSE or seizure) and interictal epileptiform activity were found in eight (11%) patients initially diagnosed in another category.

DISCUSSION

In our cohort, EEG was a key examination in the management strategy of ACS in 11% of patients admitted to the ED. It resulted in a diagnosis of epilepsy in these patients admitted with unusual confounding presentations.

Presumed first episode of nonconvulsive status epilepticus as the cause of postoperative disorder of consciousness following the completion of general anesthesia: A case report

Key Clinical Message

Disorder of consciousness can lead to irreversible sequelae without proper intervention. Consequently, early diagnosis and treatment are of paramount importance in patients with disorder of consciousness.

Abstract

Disorder of consciousness (DOC) has various etiologies. Here, we report a case in which DOC following general anesthesia was suspected as being due to the first episode of nonconvulsive status epilepticus (NCSE). An elderly man in his 80s underwent uneventful tumor resection surgery under general anesthesia for extramammary Paget's disease. After the procedure, he regained consciousness following anesthesia discontinuation and was extubated. Soon after extubation, however, although his respiratory status remained stable, his level of consciousness deteriorated to a Glasgow Coma Scale (GCS) score of E1V1M1. Head computed tomography and magnetic resonance imaging scans indicated no abnormal findings. Subsequently, involuntary movements were noted in his left upper limb. Suspecting an epilepsy episode, diazepam was administered, leading to an improvement in the level of consciousness (GCS: E4V5M6). Based on the improvement in consciousness after diazepam administration, we strongly suspected NCSE.

Epilepsy and aging

The intersection of epilepsy and aging has broad, significant implications. Substantial increases in seizures occur both in the elderly population, who are at a higher risk of developing new-onset epilepsy, and in those with chronic epilepsy who become aged. There are notable gaps in our understanding of aging and epilepsy at the basic and practical levels, which have important consequences. We are in the early stages of understanding the complex relationships between epilepsy and other age-related brain diseases such as stroke, dementia, traumatic brain injury (TBI), and cancer. Furthermore, the clinician must recognize that the presentation and treatment of epilepsy in the elderly are different from those of younger populations. Given the developing awareness of the problem and the capabilities of contemporary, multidisciplinary approaches to advance understanding about the biology of aging and epilepsy, it is reasonable to expect that we will unravel some of the intricacies of epilepsy in the elderly; it is also reasonable to expect that these gains will lead to further improvements in our understanding and treatment of epilepsy for all age groups.

Epilepsy in the Elderly: Treatment and Consideration of Comorbid Diseases

Epilepsy is the third most common neurological disorder affecting older adults after stroke and dementia, and the incidence of epilepsy is increasing rapidly in this population. A further increase in the incidence and prevalence of epilepsy is expected in aging societies. The establishment of a correct differential diagnosis between epilepsy and other seizure disorders that are common in the elderly is crucial. The symptoms of seizures in the elderly may be different from those in younger populations. The diagnosis is difficult, probably because of nonspecific characteristics, short-term symptoms, and absence of witnesses. There are three important issues in the treatment of epilepsy in the elderly: changes in pharmacokinetic parameters, polytherapy (including non-antiepileptic and antiepileptic drugs), and susceptibility to adverse drug effects. Antiepileptic drugs (AEDs) with fewer adverse effects, including cognitive effects, and AEDs without significant pharmacokinetic drug interactions are needed. Several studies found that stroke was strongly associated with a high incidence of early seizures and epilepsy. Stroke is also one of the major causes of status epilepticus. Cortical involvement and large lesions are strongly associated with the development of seizures and epilepsy. The severity of the initial neurological deficit is a strong clinical predictor of seizures after ischemic stroke. The optimal quality of life of dementia patients cannot be achieved without a proper diagnosis of coexisting epilepsy.

Comparing the efficacy of sodium valproate and levetiracetam following initial lorazepam in elderly patients with generalized convulsive status epilepticus (GCSE): A prospective randomized controlled pilot study

PURPOSE

This randomized control study was conducted to compare the efficacy of sodium valproate (SVP) and levetiracetam (LEV) following initial intravenous lorazepam in elderly patients (age: >60years) with generalized convulsive status epilepticus (GCSE) and to identify predictors of poor seizure control.

METHODS

A total of 118 patients (mean age: 67.5 ± 7.5 years, M:F = 1.6:1), who had presented with GCSE were randomized into the SVP or LEV treatment arms. All patients received initial intravenous lorazepam (0.1 mg/kg) followed by one of the two antiepileptic drugs (AEDs), parenteral SVP (20-25 mg/kg) or LEV (20-25 mg/kg). Those who failed to achieve control with the initial AED, were crossed over to receive the other AED. One-hundred patients (SVP = 50; LEV = 50) completed the study.

RESULTS

SE could be controlled with lorazepam and one of the AEDs (SVP or LEV) in 71.18% (84/118). Intention-to-treat analysis showed that the two groups did not differ significantly in terms of seizure control [SVP: 41/60 (68.3%); LEV: 43/58 (74.1%), p = 0.486]. Of 100 patients who completed the study, seizure control was achieved in 38/50(76%) in the SVP and 43/50(86%) in the LEV group (p = 0.202). After crossing over to the second AED, SE could be controlled in an additional in 50% (6/12) in SVP (+LEV) group and in 14.3% (1/7) in LEV (+SVP) group. Overall, after the second AED, seizure control was achieved in 77.1% (91/118). Higher STESS was associated with poor therapeutic response (p = 0.049).

CONCLUSIONS

The efficacy of SVP and LEV following initial lorazepam in controlling GCSE in elderly population was comparable, hence the choice of AED could be individualized.

Status epilepticus in the elderly patients: A national data study in Thailand

There are limited data in terms of incidence, clinical features, and outcomes in elderly patients with status epilepticus (SE) in national level. We retrospectively explored national data in Thailand for reimbursement of all SE in elderly patients admitted in the fiscal year 2004-2012. SE in elderly patients (age>60years old) were diagnosed and searched based on ICD 10 (G41) from the national database of from the National Health and Security Office. There were 3326 SE in elderly patients. The national incidence of SE was highest at 8.78patients/100,000/year in 2012. The average age was 72.02years and most were males (1379 patients; 58.8%). At discharge, 66% of patients had improved and in-hospital mortality rate was 14.5%. Predictors of poor outcomes were older age≥80years, being female, hospital levels, chronic renal failure, central nervous system infection, respiratory failure, pneumonia, septicemia, shock, acute renal failure, and hyperkalemia. In conclusion, the number of cases of SE in elderly patients in Thailand has been increasing annually. Increasing age was associated with poor outcome in admitted elderly SE patients.

Status Epilepticus: Epidemiology and Public Health Needs

Status epilepticus (SE) is defined as a continuous clinical and/or electrographic seizure activity lasting five minutes or more or recurrent seizure activity without return to baseline. There is a paucity of epidemiological studies of SE, as most research is derived from small population studies. The overall incidence of SE is 9.9 to 41 per 100,000/year, with peaks in children and the elderly and with febrile seizures and strokes as its main etiologies. The etiology is the major determinant of mortality. Governments and the academic community should predominantly focus on the primary prevention of etiologies linked to SE, as these are the most important risk factors for its development. This review describes the incidence, prevalence, etiology, risk factors, outcomes and costs of SE and aims to identify future research and public health needs.

Pharmacotherapy Overview of Seizure Management in the Adult Emergency Department

Seizures are a common cause of emergency department visits, and approximately 28% of epilepsy patients present to an emergency department annually for treatment. This article will provide an overview of the pharmacotherapeutic management of seizures and anticonvulsant therapy for patients who present to the adult emergency department, including practical information for pharmacists covering or cross-covering this practice area. The benzodiazepines are reviewed as a class, including dosing strategies, pharmacodynamic considerations, and advantages and disadvantages of lorazepam, diazepam, and midazolam. Indications for the use of phenytoin and fosphenytoin will be reviewed, as well as dosing, adverse effects, and cost-effectiveness data. In addition, dosing, administration, pharmacokinetics, and adverse effects of phenobarbital, carbamazepine, and valproate will be discussed. Clinical indications for serum anticonvulsant concentration monitoring and subsequent calculation of loading doses from serum concentrations are reviewed. Since status epilepticus is a life-threatening emergency, its therapeutic management is reviewed, including the use of continuous infusion midazolam, pentobarbital, and propofol. There are many opportunities for clinical pharmacists to collaborate with other members of the health care team to optimize efficacy and minimize adverse effects of anticonvulsant agents in the emergency department setting.

Early-Onset Convulsive Seizures Induced by Brain Hypoxia-Ischemia in Aging Mice: Effects of Anticonvulsive Treatments

Aging is associated with an increased risk of seizures/epilepsy. Stroke (ischemic or hemorrhagic) and cardiac arrest related brain injury are two major causative factors for seizure development in this patient population. With either etiology, seizures are a poor prognostic factor. In spite of this, the underlying pathophysiology of seizure development is not well understood. In addition, a standardized treatment regimen with anticonvulsants and outcome assessments following treatment has yet to be established for these post-ischemic seizures. Previous studies have modeled post-ischemic seizures in adult rodents, but similar studies in aging/aged animals, a group that mirrors a higher risk elderly population, remain sparse. Our study therefore aimed to investigate early-onset seizures in aging animals using a hypoxia-ischemia (HI) model. Male C57 black mice 18-20-month-old underwent a unilateral occlusion of the common carotid artery followed by a systemic hypoxic episode (8% O2 for 30 min). Early-onset seizures were detected using combined behavioral and electroencephalographic (EEG) monitoring. Brain injury was assessed histologically at different times post HI. Convulsive seizures were observed in 65% of aging mice post-HI but not in control aging mice following either sham surgery or hypoxia alone. These seizures typically occurred within hours of HI and behaviorally consisted of jumping, fast running, barrel-rolling, and/or falling (loss of the righting reflex) with limb spasms. No evident discharges during any convulsive seizures were seen on cortical-hippocampal EEG recordings. Seizure development was closely associated with acute mortality and severe brain injury on brain histological analysis. Intra-peritoneal injections of lorazepam and fosphenytoin suppressed seizures and improved survival but only when applied prior to seizure onset and not after. These findings together suggest that seizures are a major contributing factor to acute mortality in aging mice following severe brain ischemia and that early anticonvulsive treatment may prevent seizure genesis and improve overall outcomes.

Pharmacotherapy for Status Epilepticus

Status epilepticus (SE) represents the most severe form of epilepsy. It is one of the most common neurologic emergencies, with an incidence of up to 61 per 100,000 per year and an estimated mortality of 20 %. Clinically, tonic-clonic convulsive SE is divided into four subsequent stages: early, established, refractory, and super-refractory. Pharmacotherapy of status epilepticus, especially of its later stages, represents an "evidence-free zone," due to a lack of high-quality, controlled trials to inform clinical decisions. This comprehensive narrative review focuses on the pharmacotherapy of SE, presented according to the four-staged approach outlined above, and providing pharmacological properties and efficacy/safety data for each antiepileptic drug according to the strength of scientific evidence from the available literature. Data sources included MEDLINE and back-tracking of references in pertinent studies. Intravenous lorazepam or intramuscular midazolam effectively control early SE in approximately 63-73 % of patients. Despite a suboptimal safety profile, intravenous phenytoin or phenobarbital are widely used treatments for established SE; alternatives include valproate, levetiracetam, and lacosamide. Anesthetics are widely used in refractory and super-refractory SE, despite the current lack of trials in this field. Data on alternative treatments in the later stages are limited. Valproate and levetiracetam represent safe and effective alternatives to phenobarbital and phenytoin for treatment of established SE persisting despite first-line treatment with benzodiazepines. To date there are no class I data to support recommendations for most antiepileptic drugs for established, refractory, and super-refractory SE. Limiting the methodologic heterogeneity across studies is required and high-class randomized, controlled trials to inform clinicians about the best treatment in established and refractory status are needed.

Modeling early-onset post-ischemic seizures in aging mice

Stroke is the leading cause of seizures and epilepsy in the aged population, with post-stroke seizures being a poor prognostic factor. The pathological processes underlying post-stroke seizures are not well understood and studies of these seizures in aging/aged animals remain scarce. Therefore, our primary objective was to model post-stroke seizures in aging mice (C57 black strain, 16-20 months-old), with a focus on early-onset, convulsive seizures that occur within 24-hours of brain ischemia. We utilized a middle cerebral artery occlusion model and examined seizure activity and brain injury using combined behavioral and electroencephalographic monitoring and histological assessments. Aging mice exhibited vigorous convulsive seizures within hours of the middle cerebral artery occlusion. These seizures manifested with jumping, rapid running, barrel-rolling and/or falling all in the absence of hippocampal-cortical electrographic discharges. Seizure development was closely associated with severe brain injury and acute mortality. Anticonvulsive treatments after seizure occurrence offered temporary seizure control but failed to improve animal survival. A separate cohort of adult mice (6-8 months-old) exhibited analogous early-onset convulsive seizures following the middle cerebral artery occlusion but had better survival outcomes following anticonvulsive treatment. Collectively, our data suggest that early-onset convulsive seizures are a result of severe brain ischemia in aging animals.

Nonconvulsive status epilepticus disguising as hepatic encephalopathy

Nonconvulsive status epilepticus has become an important issue in modern neurology and epileptology. This is based on difficulty in definitively elucidating the condition and its various clinical phenomena and on our inadequate insight into the intrinsic pathophysiological processes. Despite nonconvulsive status epilepticus being a situation that requires immediate treatment, this disorder may not be appreciated as the cause of mental status impairment. Although the pathophysiology of nonconvulsive status epilepticus remains unknown, this disorder is thought to lead to neuronal damage, so its identification and treatment are important. Nonconvulsive status epilepticus should be considered in the differential diagnosis of patients with liver cirrhosis presenting an altered mental status. We report a case of a 52-year-old male with liver cirrhosis presenting an altered mental status. He was initially diagnosed with hepatic encephalopathy but ultimately diagnosed with nonconvulsive status epilepticus by electroencephalogram.

Aetiology and outcome of generalized convulsive status epilepticus in elderly

PURPOSE

Convulsive status epilepticus (CSE) is a common neurologic emergency in elderly people. The current study elaborates the clinical characteristics and outcome of CSE in elderly patients.

METHODS

Analysis of data of generalized CSE patients, aged 60 years and above admitted at the neurointensive care unit (NICU) was performed. The primary outcome for analysis was in-hospital mortality. The study population was divided into groups based on progression of CSE and mortality to analyze difference in study variables. Mortality of the group was analyzed using life tables.

RESULTS

A total of 33 patients satisfied the inclusion criteria from medical records of 212 patients with CSE. Mean age of the study population was 67.0 ± 6.8 years; 69.7% were men. Acute symptomatic aetiology was the commonest cause of CSE (60.6%); nine (27.3%) patients progressed to refractory status epilepticus (RSE) of which five patients had prolonged RSE. The overall mortality was 18.2%. Complications of mechanical ventilation and mean age were higher in patients who died. Though vascular aetiology was the leading cause of CSE (39.3%), it was not associated with progression to RSE or mortality. Acute symptomatic aetiology accounted for five out of the six deaths in the entire cohort.

CONCLUSION

Less than one-third of elderly patients with CSE progressed to RSE. Vascular aetiology, the leading cause of generalized CSE in elderly, was not associated with progression to RSE and mortality. Acute symptomatic aetiology was associated with high mortality.

Management of refractory status epilepticus in an actively dying patient

No consensus guidelines exist for the treatment of refractory myoclonic status epilepticus or refractory myoclonus in the palliative care setting. Evidence-based guidelines for the general medical population are often neither practical nor applicable at the end of life. Many challenges, including medication availability, route of administration, monitoring, and work-up are all unique to the palliative care setting. Two patients with refractory myoclonus versus refractory myoclonic status epilepticus are described here, illustrating the challenges involved in treatment as well the need for further research for therapy in the palliative care setting.

Usefulness of video-EEG in the paediatric emergency department

Over the past two decades the EEG has technically improved from the use of analog to digital machines and more recently to video-EEG systems. Despite these advances, recording a technically acceptable EEG in an electrically hostile environment such as the emergency department (ED) remains a challenge, particularly with infants or young children. In 1996, a meeting of French experts established a set of guidelines for performing an EEG in the ED based on a review of the available literature. The authors highlighted the most suitable indications for an emergency EEG including clinical suspicion of cerebral death, convulsive and myoclonic status epilepticus, focal or generalized relapsing convulsive seizures as well as follow-up of known convulsive patients. They further recommended emergency EEG in the presence of doubt regarding the epileptic nature of the presentation as well as during the initiation or modification of sedation following brain injury. Subsequently, proposals for expanding the use of EEG in emergency patients have been advocated including trauma, vascular and anoxic-ischemic injury due to cardiorespiratory arrest, postinfective encephalopathy and nonconvulsive status epilepticus. The aim of this review is to show the diagnostic importance of video-EEG, as well as highlighting the predictive prognostic factors for positive and negative outcomes, when utilized in the pediatric ED for seizures as well as other neurological presentations.

Seizures and epilepsy in elderly patients of an urban area of Iran: clinical manifestation, differential diagnosis, etiology, and epilepsy subtypes

The incidences of seizures and epilepsy in the population show a peak after 60 years of age. Due to the lack of reported clinical aspects of seizure and epilepsy in the older patients in our region in Iran, this study was conducted to describe the clinical manifestation, etiology, differential diagnosis, and epilepsy subtypes of epilepsy and seizure. A cross-sectional retrospective study was performed on all consecutively elderly seizure and epilepsy patients, referred to the Epilepsy Association in the city of Qom, Iran over a 10-year period. A total of 466 patients aged >60 years were admitted. 31 % of the patients had epilepsy or seizure and 69 % of them had non-epileptic events. The most prevalent differential diagnoses in the beginning were syncope and cardiovascular disorders. The most frequent clinical symptom of epilepsy was generalized tonic-clonic seizures (75 %). The most common cause of seizure was systemic metabolic disorder (27 %). In epileptic elderly patients, no cause was ascertained for 38 % and the most frequently observed pathological factors were cerebrovascular diseases, which accounted for 24 %. The most common type of epileptic seizure was generalized epileptic seizures (75 %). 10 % of elderly epileptic patients suffered from status epilepticus, which was primarily caused by anoxia. Despite the rising rate and potentially profound physical and psychosocial effects of seizures and epilepsy, these disorders have received surprisingly little research focus and attention in Iran. Referring older patients to a specialist or a specialist epilepsy center allows speedy assessment, appropriate investigation and treatment, and less likely to miss the diagnosis.

Status epilepticus in the elderly: epidemiology, clinical aspects and treatment

The aim of the study was to review the epidemiology, clinical profile and discuss the etiology, prognosis and treatment options in patients aged 60 years or older presenting with status epilepticus. We performed a systematic review involving studies published from 1996 to 2010, in Medline/PubMed, Scientific Electronic Library on line (Scielo), Latin-American and Caribbean Center of Health Sciences Information (Lilacs) databases and textbooks. Related articles published before 1996, when relevant for discussing epilepsy in older people, were also included. Several population studies had shown an increased incidence of status epilepticus after the age of 60 years. Status epilepticus is a medical and neurological emergency that is associated with high morbidity and mortality, and is a major concern in the elderly compared to the general population. Prompt diagnosis and effective treatment of convulsive status epilepticus are crucial to avoid brain injury and reduce the fatality rate in this age group.

Thyroid-stimulating hormone elevation misdiagnosed as subclinical hypothyroidism following non-convulsive status epilepticus: a case report

Introduction

Non-convulsive status epilepticus is a form of epileptic seizure that occurs without convulsions. Recent reviews suggest that the diagnosis of non-convulsive status epilepticus remains difficult. Here, we report the case of a patient with thyroid-stimulating hormone elevation misdiagnosed as subclinical hypothyroidism following non-convulsive status epilepticus.

Case presentation

Our patient was a 68-year-old Japanese woman. The results of endocrine testing after her first episode of non-convulsive status epilepticus suggested latent subclinical hypothyroidism: she had elevated thyroid-stimulating hormone with normal levels of free tri-iodothyronine and free thyroxine. On examination, a diagnosis of thyroid disorder was not supported by other test results and our patient remained untreated. A follow-up examination revealed that her thyroid-stimulating hormone levels had spontaneously normalized. When she consulted another doctor for confusion, the transient increase in thyroid-stimulating hormone levels following non-convulsive status epilepticus was mistaken for subclinical hypothyroidism, and unfortunately treated with levothyroxine. Our patient then experienced levothyroxine-induced non-convulsive status epilepticus.

Conclusions

In this report, we suggested possible mechanisms for latent hypothyroid-like hormone abnormality following epileptic seizures and the possibility of provoking epileptic seizures by administering levothyroxine for misdiagnosed subclinical hypothyroidism.

Role of oxidative stress in epileptic seizures

Oxidative stress resulting from excessive free-radical release is likely implicated in the initiation and progression of epilepsy. Therefore, antioxidant therapies aimed at reducing oxidative stress have received considerable attention in epilepsy treatment. However, much evidence suggests that oxidative stress does not always have the same pattern in all seizures models. Thus, this review provides an overview aimed at achieving a better understanding of this issue. We summarize work regarding seizure models (i.e., genetic rat models, kainic acid, pilocarpine, pentylenetetrazol, and trimethyltin), oxidative stress as an etiologic factor in epileptic seizures (i.e., impairment of antioxidant systems, mitochondrial dysfunction, involvement of redox-active metals, arachidonic acid pathway activation, and aging), and antioxidant strategies for seizure treatment. Combined, this review highlights pharmacological mechanisms associated with oxidative stress in epileptic seizures and the potential for neuroprotection in epilepsy that targets oxidative stress and is supported by effective antioxidant treatment.

The new wave: time to bring EEG to the emergency department

Emergency electroencephalography (EEG) is indicated in the diagnosis and management of non-convulsive status epilepticus (NCSE) underlying an alteration in the level of consciousness. NCSE is a frequent, treatable, and under-diagnosed entity that can result in neurological injury. This justifies the need for EEG availability in the emergency department (ED). There is now emerging evidence for the potential benefits of EEG monitoring in various acute conditions commonly encountered in the ED, including convulsive status after treatment, breakthrough seizures in chronic epilepsy patients who are otherwise controlled, acute head trauma, and pseudo seizures. However, attempts to allow for routine EEG monitoring in the ED face numerous obstacles. The main hurdles to an optimized use of EEG in the ED are lack of space, the high cost of EEG machines, difficulty of finding time, as well as the expertise needed to apply electrodes, use the machines, and interpret the recordings. We reviewed the necessity for EEGs in the ED, and to meet the need, we envision a product that is comprised of an inexpensive single-use kit used to wirelessly collect and send EEG data to a local and/or remote neurologist and obtain an interpretation for managing an ED patient.

High prevalence of nonconvulsive and subtle status epilepticus in an ICU of a tertiary care center: a three-year observational cohort study

BACKGROUND

Status epilepticus is one of the most important neurological emergencies and requires immediate therapy and admission to the intensive care unit. We hypothesized that nonconvulsive and subtle status epilepticus are more frequent than reported.

METHODS

This observational cohort study describes types, courses, duration, length of hospital stay, outcome and case fatality rate of status epilepticus in adults in relation to demographic and clinical variables. It was conducted in an intensive care unit of a tertiary care center over three years.

RESULTS

111 status epilepticus episodes had a median duration of 48h. Hospitalization length was 18±15.3 days. 81% of the status epilepticus episodes were nonconvulsive and subtle. Case fatality rate was 17%. Age over 70 years had independent positive influence on status epilepticus course (OR: 5.135; p=0.0029). Hospital stay increased by 1.13h with each additional hour of status epilepticus (p=0.02). Subtle status epilepticus was a risk factor for refractoriness (p=0.0065).

CONCLUSIONS

Prevalence of nonconvulsive and subtle status epilepticus was higher than reported, emphasising the importance of clinical awareness. Older age was associated with more favorable course. This unexpected and contradictory result has to be taken into account during therapeutic interventions in the elderly and should warn from early resignation regarding treatment.

Prescribing pattern of anti-epileptic drugs in an Italian setting of elderly outpatients: a population-based study during 2004-07

AIMS

The aims of the study were to assess the trend of older and newer anti-epileptic drugs (AEDs) in the elderly population and to analyze the effects of a health-policy intervention with regard to AED use in general practice in a setting in Southern Italy.

METHODS

Data were extracted from the 'Caserta-1' Local-Health-Unit Arianna database in the years 2004-07. Patients aged over 65 years, receiving at least one AED prescription and registered in the lists of 88 general practitioners, were selected. The use of older and newer AEDs was calculated as 1 year prevalence and incidence of use and defined daily dose (DDD) per 1000 inhabitants day(-1) . Sub-analyses by gender, age and indication of use were performed.

RESULTS

Most of AED users were treated because of neuropathic pain (64.8%). However, the main indication of use for older AEDs (57.8%) was epilepsy, whereas newer AEDs (79.5%) were used for neuropathic pain. Prevalence and incidence of newer AED use increased until 2006, followed by a reduction in 2007. Newer AEDs, particularly gabapentin and pregabalin, were used in the treatment of more patients than older AEDs. However phenobarbital, accounting for more than 50% of total AED volume, was the most prescribed medication during the entire study period.

CONCLUSIONS

An increasing use of AEDs has been observed during 2004-07, mostly due to the prescription of newer compounds for neuropathic pain. The fall in the use of newer AEDs during 2007 coincides with revised re-imbursement criteria for gabapentin and pregabalin. The large use of phenobarbital in the elderly should be considered in the light of a risk of adverse drug reactions.

Nonconvulsive status epilepticus in palliative care patients

Altered mental status and reduced level of consciousness are common among patients admitted to palliative care units. However, nonconvulsive status epilepticus (NCSE) has rarely been considered as a possible cause, and electroencephalographic confirmation of the epileptic status is sparse. The clinical presentation of patients with NCSE varies from altered mental status to coma, with no or only minimal convulsions. We report a prospective evaluation of patients with altered mental status on admission to our palliative care unit in the year 2007. Of 290 patients admitted in 2007, 49 patients showed signs of confusion or delirium and/or a reduction in their level of consciousness. NCSE was suspected clinically in 22 of these patients, and epileptic activity could be confirmed in 15 (5.2%) of 290 patients. Nine of 15 patients could be effectively treated with anticonvulsants and regained communication ability before death. NCSE appears to be an important, often unrecognized, and potentially treatable cause of altered mental status in palliative care patients. Pharmacological treatment might restore communicative abilities even in severely ill patients.

Intravenous levetiracetam as treatment for status epilepticus

There are established drugs for the treatment of status epilepticus (SE) but their potentially hazardous side-effects are well known. Levetiracetam (LEV) is a novel anticonvulsant available for intravenous (i.v.) application. It could be an alternative when standard drugs fail or should be avoided. We retrospectively identified patients from two German teaching hospitals who were treated with LEV i.v. for SE. Their charts were reviewed regarding sociodemographic data, type, etiology, onset and duration of SE, dose of LEV, concurrent antiepileptic drugs (AED) treatment, tolerability, and outcome. Thirty-two patients (15 female) were found who were treated with i.v. LEV for SE (median age 71 years). Two patients were exclusively treated with LEV. Eight received a low and further 20 patients a high dose of benzodiazepines before LEV. Two patients were treated with LEV to enable discontinuation of narcosis. SE was generalized convulsive in five, nonconvulsive in 20, and simple focal in seven patients. Etiology was acute 13 times and remote symptomatic 16 times; three SE were of unknown etiology. Therapy was initiated within a median time of 3 h and LEV i.v. was applied within a median time of 6 h. Median LEV bolus was 2,000 mg; median total dose on day 1 was 3,500 mg. Benzodiazepines plus i.v. LEV terminated SE in 23 patients without application of additional anticonvulsants, 10 within 30 min. LEV could not terminate SE in seven patients. We documented nausea and emesis in one and elevation of liver enzymes in another patient that were likely to be attributed to LEV. LEV i.v. seems to be safe with relevant efficiency for the treatment of SE in elderly and multimorbid patients when comorbidity and respiratory insufficiency precludes high doses of benzodiazepines or phenytoin.

Nonconvulsive status epilepticus in terminally ill patients-a diagnostic and therapeutic challenge

Nonconvulsive status epilepticus (NCSE) is rarely considered as a cause of confusion in terminally ill patients. The clinical presentation varies from altered mental status to coma, without visible convulsions. Electroencephalogram is the most important diagnostic tool to identify epileptiform activity. Treatment should be initiated following a stepwise model, avoiding intubation and transfer to the intensive care unit. Although mortality rates are high, in some patients NCSE can be reversed by treatment. NCSE should be considered in a differential diagnosis of all terminally ill patients with sudden mental status changes. We present two cases and discuss treatment options and the borders of therapy.

An alternative perspective on the management of status epilepticus

The definition of status epilepticus (SE) has been reduced from 30 minutes to 5 minutes and this article questions if treatment should not be offered before reaching that window. After provision of first aid, benzodiazepines (BDZ) are the initial form of intervention, with either nasal or buccal midazolam being favored for nonprofessionals. Proper patient supervision, including admission to an intensive care unit for more difficult patients, is endorsed, and the need to warn nonprofessionals of the potential risk of respiratory depression is imperative. The article criticizes the use of phenytoin as the antiepileptic medication (AEM) with which to load patients, as it is no longer a first-line AEM, and argues in favor of using a first-line AEM such as valproate or carbamazepine, or preferably the AEM that previously proved efficacious in a patient with known epilepsy who was noncompliant. Alternative routes of administration of AEMs are discussed, and the use of blood level monitoring, as an adjunct to management, to protect against further episodes of SE, is supported. Touched on in this article are the use of some of the newer AEMs in the management of SE and exploration of treatment strategies that acknowledge that treatment must also include patient education that incorporates techniques to enhance compliance.

Status epilepticus: evidence and controversy

Status Epilepticus (SE) is a potential and relatively common complication of epileptic seizures. Traditionally, SE was defined as 30 minutes of continuous seizure activity or a series of seizures without return to full consciousness between the seizures. As a practical rule, it is admitted that all patients arriving at the emergency room suffering from epileptic seizures could have SE and should be treated accordingly. It is well known that the longer an attack has lasted, the more difficult it is to control in the next 5 to 10 minutes. On the other hand, once an attack has lasted for over 5 to 10 minutes, it is unlikely to cease spontaneously. Ambulatory intervention should focus on this "therapeutic interval" in acute attacks with the use of first-line drugs such as the intramuscular, rectal, oral, and/or intranasal application of benzodiazepines (BZD). Treatment of SE is a medical emergency, which should include 3 priority objectives: (1) to stop the seizures; (2) to maintain internal homeostasis; and (3) to treat possible complications. Current consensus is that a BZD, notably lorazepam or diazepam, is the initial class of drug for the treatment of SE. Phenytoin, fosphenytoin, or valproate generally is agreed upon as the next drugs to be administered. Failure to respond to optimal BZD and phenytoin loading operationally defines refractory SE.

Epileptic fits and epilepsy in the elderly: general reflections, specific issues and therapeutic implications

Seizures and epilepsy are commonly encountered in the elderly. Diagnosis is not always straightforward as reliable history is often difficult to obtain and EEG findings can be non-specific. When to treat and how may be difficult choices as adequate studies in elderly are rather scarce. Treatment should be based on careful assessment and comparison of risk/benefit profiles of various anti-epileptic drugs (AEDs) in this specific elderly population. Since most AEDs are effective in terms of seizure control in the elderly, the choice of treatment is often determined by tolerability, pharmacokinetic profile and drug interactions of AEDs. As recently introduced AEDs have a better safety profile compared to older agents it seems logical to initiate treatment in the frail elderly patient with those more modern AEDs. In this review some distinctive clinical features of epilepsy in the elderly are discussed in three sections (general issues, special issues and selected treatment options with special reference to medicinal treatment).

Kainate-induced seizures, oxidative stress and neuronal loss in aging rats

Aging is a significant risk factor for developing epilepsy. The mechanisms underlying age-related increase in seizure susceptibility and resultant injury remain unknown. Oxidative stress is an important mechanism that contributes to diverse age-related disorders. Whether age-related increased seizure susceptibility is accompanied by increased oxidative stress remains unknown. The goal of this study was to determine if aging per se increases the susceptibility of rats to kainate-induced behavioral seizures and oxidative stress. Adult (3-4 month-old) and aging (18-19 month-old) Sprague-Dawley rats were administered a single low dose of kainate (5 mg/kg, s.c.) or saline. Behavioral seizures were monitored in all four groups for a period for a period of approximately 6 h. Oxidative stress (8-hydroxy-2'deoxyguanosine/2-deoxyguanosine; 8OHdG/2dG) was assessed 24 h following kainate injection. Stereological assessment of cell counts was performed in hippocampal tissue 7 days following kainate injection. In adult rats, administration of the low dose of kainate did not produce significant behavioral seizures, oxidative stress or cell loss. However, aging rats exhibited intense behavioral seizures consistent with status epilepticus following the low dose of kainate. In aging rats, kainate produced a significant increase in oxidative DNA damage (8OHdG/2dG) and neuronal loss in cornu ammonis regions 3 and 1 (CA3 and CA1), but not dentate gyrus compared with both age-matched controls and adult kainate-treated rats. These data suggest that the process of aging per se increases kainate-induced seizure susceptibility, oxidative stress and hippocampal pyramidal cell loss.

Special issues in the management of young children, older adults, and the developmentally disabled

The very young, the very old, and those with developmental disability have an increased risk of both epilepsy and prolonged and repetitive seizures. The special issues that affect their management are reviewed. Polypharmacy that occurs because of comorbid illnesses requiring chronic medication can result in dangerous drug-drug interactions. The antiepileptic drug's pharmacokinetic profile must be factored when treating young children and older adults. Patients who have taken an older enzyme-inducing antiepileptic drug for years may have a markedly induced hepatic enzyme system that may alter drug metabolism. Overdose or toxicity may occur in older adults who may metabolize and clear antiepileptic drugs more slowly than younger patients. Benzodiazepines are the most rapidly effective acute therapy for repetitive or prolonged seizures. It is important to have a plan for management of prolonged and repetitive seizures. Long-term therapy should be managed in a manner that will eliminate the need for rescue therapies and visits to the emergency department.

Treatment of Nonconvulsive Status Epilepticus

Nonconvulsive status epilepticus (NCSE) is relatively common; it comprises at least one third of all cases of status epilepticus. NCSE may be an even more common, yet more elusive, condition in the elderly population. NCSE can be divided into complex partial status epilepticus (CPSE), NCSE in coma, and typical absence status epilepticus (TAS). The clinical manifestations may be subtle, and thus the diagnosis of these conditions is critically dependent on electroencephalography (EEG). When EEG demonstrates typical ictal patterns, the diagnosis is usually straightforward. However, in many circumstances the EEG pattern has to be differentiated from other encephalopathic patterns, and this differentiation can prove troublesome; clinical and electrographic response to treatment can prove helpful in these situations. The prognosis for NCSE in the elderly is generally poor due to the underlying etiology rather than the persistence of electrographic discharges. Whether the neuronal damage that occurs in convulsive status epilepticus and in animal models of limbic status epilepticus also occurs in NCSE in humans is still a matter of debate. Intravenous treatment is not benign, especially in the elderly, who may be at greater risk of systemic complications from hypotensive and sedative agents. Therefore, a more conservative approach to the treatment of NCSE in the elderly is warranted. Oral benzodiazepines should be used for the treatment of TAS and CPSE in noncomatose patients with a prior history of epilepsy, and in some circumstances, intravenous medication may be necessary. Generally, anesthetic coma should not be advised in either of these conditions. A more aggressive approach may be required with NCSE in coma, in the hope of improving a very poor prognosis. Treatment regimens will remain largely speculative until there are more relevant animal models and controlled trials of conservative versus aggressive treatment.

Epidemiology and outcomes of status epilepticus in the elderly

Status epilepticus (SE) is a serious condition of prolonged or repetitive seizures. The annual incidence (86/100,000) of SE in the elderly who are aged 60 and greater is almost twice that of the general population and is even higher in those who are 70 years and older. Either acute or remote symptomatic stroke causes approximately 60% of SE seen in the elderly. SE is associated with a high mortality in the elderly (38%), with a rate approaching 50% in patients older than 80 years of age. Etiology is a strong determinant of mortality in the elderly: mortality approaches 100% in patients with anoxia and 30% in patients with either metabolic disorders, hemorrhages, tumors, or systemic infections. Mortality is almost three times higher in SE associated with acute ischemic stroke than in stroke alone, indicating synergistic effects. Duration of SE is also a factor in mortality. Treatment should be initiated for any convulsive seizure that lasts at least 10 min or is repetitive. An electroencephalogram (EEG) should be promptly obtained so that a diagnosis can be made without delay. Because older patients have a greater likelihood of nondiagnostic findings on routine EEGs, prolonged EEG recordings and inpatient video-EEG monitoring significantly increase the rate of establishing a definitive diagnosis. Nonconvulsive status epilepticus in the elderly is especially difficult to diagnose and should be evaluated with an EEG. Treatment of SE is complicated by altered pharmacokinetics in the elderly. Initial treatments, usually the administration of an intravenous benzodiazepine, have overall success rates of 55% for overt convulsive SE and 14.9% for subtle SE. For refractory SE, little is gained by using additional standard drugs, and general anesthesia with continuous EEG monitoring is recommended.

[Refractory status epilepticus: diagnosis, therapy, course, and prognosis]

Status epilepticus (SE) is a frequent neurological emergency with an annual incidence of 10-20/100,000 individuals. The overall mortality is about 10-20%. Patients present with long-lasting fits or series of epileptic seizures or extended stupor and coma. Furthermore, patients with SE can suffer from a number of systemic complications possibly also due to side effects of the medical treatment. In the beginning, standardized treatment algorithms can successfully stop most SE. A minority of SE cases prove however to be refractory against the initial treatment and require intensified pharmacologic intervention with nonsedating anticonvulsive drugs or anesthetics. In some partial SE, nonpharmacological approaches (e.g., epilepsy surgery) have been used successfully. This paper reviews scientific evidence of the diagnostic approach, therapeutic options, and course of refractory SE, including nonpharmacological treatment.

Treatment of seizure emergencies: Convulsive and non-convulsive status epilepticus

Status epilepticus (SE), defined as recurrent epileptic seizures without complete recovery between seizures, is one of the most serious manifestations of epilepsy. Generalized convulsive status epilepticus (GCSE) is the most common and most life-threatening form of SE, and aging increases the mortality risk. In a recent study of treatment of GCSE, 226 of 518 evaluable patients (43.6%) were of age 65 or older. In the 157 elderly patients with overt GCSE, phenobarbital was successful as first-line treatment in 71.4%, lorazepam in 63%, diazepam and phenytoin in 53.3%, and phenytoin alone in 41.5%. Phenobarbital and lorazepam were more successful than phenytoin alone. In the 69 elderly patients with subtle GCSE, success as the first treatment was 30.8% for phenobarbital, 14.3% for lorazepam, 11.8% for phenytoin, and 7.7% for diazepam and phenytoin. Overall, the results were similar to those reported for the entire study. Lorazepam, because of ease of use, is probably the best drug for the initial treatment of overt GCSE in the elderly; phenobarbital may be the best drug for subtle GCSE in this group, but more data are needed. The term "nonconvulsive SE" has been used to include complex partial SE and absence SE - both of which present as an "epileptic twilight state" - and SE in comatose patients. The diagnosis can be challenging, particularly in the elderly, as overlapping clinical features and electroencephalogram patterns can be seen in SE and in a variety of encephalopathic conditions. There is a suggestion that aggressive treatment of elderly patients with nonconvulsive SE may worsen prognosis. Clearly, there is a need for more data to better understand management of elderly patients with both convulsive and nonconvulsive SE.

Mitochondrial dysfunction and oxidative stress: cause and consequence of epileptic seizures

Mitochondrial dysfunction has been implicated as a contributing factor in diverse acute and chronic neurological disorders. However, its role in the epilepsies has only recently emerged. Animal studies show that epileptic seizures result in free radical production and oxidative damage to cellular proteins, lipids, and DNA. Mitochondria contribute to the majority of seizure-induced free radical production. Seizure-induced mitochondrial superoxide production, consequent inactivation of susceptible iron-sulfur enzymes, e.g., aconitase, and resultant iron-mediated toxicity may mediate seizure-induced neuronal death. Epileptic seizures are a common feature of mitochondrial dysfunction associated with mitochondrial encephalopathies. Recent work suggests that chronic mitochondrial oxidative stress and resultant dysfunction can render the brain more susceptible to epileptic seizures. This review focuses on the emerging role of oxidative stress and mitochondrial dysfunction both as a consequence and as a cause of epileptic seizures.

Aging alters electroencephalographic and clinical manifestations of kainate-induced status epilepticus

PURPOSE

The elderly exhibit an increased risk for developing status epilepticus and status-related morbidity and mortality. However, it is unclear how aging alters the progression of electroencephalographic (EEG) activity and behavioral manifestations during status epilepticus.

METHODS

A repetitive low-dose kainate treatment protocol (2.5 mg/kg/h; i.p.) was used in this study in conjunction with EEG and behavioral monitoring from freely behaving adult (7-8 months) and aged (22-25 months) Fischer 344 rats to assess the effects of aging on status epilepticus.

RESULTS

During kainate treatment, both groups exhibited an increase in EEG power that corresponded with the time course of kainate treatment. However, visual inspection and spectral analysis revealed a reduction of the faster frequencies (12.5-35 Hz) in the EEGs of aged rodents. A similar progression of behavioral manifestations was observed in adult and aged rodents during kainate treatment, although the frequency of preseizure manifestations (e.g., wet-dog shakes; aged rats, 110 events/h vs. adults, 25 events/h; median values) was greater, and latency to onset for any given behavioral manifestation (e.g., class V seizures; aged median, 60 min, vs. adult median, 145 min) was consistently shorter within the aged group.

CONCLUSIONS

These data reveal that aged Fischer 344 rats exhibit altered EEG activity (reduction of higher frequencies) and clinical manifestations during kainate-induced status epilepticus. Taken together, these data indicate an age-related change in seizure onset and spread after exposure to glutamate analogues.

Status epilepticus: a review of different syndromes, their current evaluation, and treatment

BACKGROUND

Status epilepticus (SE) encompasses a wide range of seizure types with different clinical presentations, pathophysiologies, treatment imperatives, and outcomes. The most dramatic and life-threatening form, generalized convulsive status epilepticus, has been reviewed in all of these aspects, but other less common types of SE have been described less extensively.

REVIEW SUMMARY

Definitions of generalized convulsive SE and its pathophysiology are reviewed briefly. Defining SE by a specific duration of seizures is controversial and has implications for studies and for clinical management. Several types of SE are different in their causes, presentations, and outcomes. Many are underdiagnosed. This article focuses on the pharmacology and clinical studies of several anticonvulsant medications used to treat SE. A protocol approach is not detailed. Rather, the clinical evaluation begins with meticulous diagnosis of the type of SE. Establishing the SE syndrome diagnosis and use of anticonvulsants with demonstrated effectiveness facilitate an appropriate treatment plan for individual patients. Recent developments in the basic science of SE raise the possibility of better treatments in the future.

CONCLUSIONS

As there are many types of seizures, there are also many types of SE. Each has unique presentations and treatment considerations. Review of actual clinical data from SE treatment studies should be helpful in devising the best treatment for an individual patient.

Diagnosis and Treatment of Nonconvulsive Status Epilepticus in an Intensive Care Unit Setting

Nonconvulsive status epilepticus (NCSE) in adults is a heterogeneous epileptic emergency and includes absence status (AS), complex-partial status epilepticus (CPSE), and the status epilepticus of epileptic encephalopathy (SEEE). The latter seems to be strikingly frequent among patients in intensive care units (ICU). Diagnosis of NCSE is difficult, but has to be made quickly. It relies on clinical signs and a confirmation electroencephalography (EEG). According to the different etiologies and outcomes of AS, CPSE, and SEEE, treatment has to be individually adapted, but needs to follow some basic principles--treatment should take place in the ICU and be monitored by continuous EEG. With a few exceptions, the first drug is an intravenous benzodiazepine, mainly lorazepam. Intravenous fosphenytoin or phenytoin or valproate may follow next. If some forms of NCSE are resistant to first- and second-line treatments, single or combinations of anesthetics and enteral antiepileptic drugs (AEDs) may be added. This opinion is not evidence-based, and randomized controlled prospective trials to evaluate optimal treatment of NCSE are of first priority.