Beta activity in status epilepticus

Focal beta activity on scalp EEG is a rare seizure pattern that has most extensively been studied in patients undergoing evaluation for epilepsy surgery. However, ictal beta activity is uncommon beyond this population and has not been reported in human status epilepticus. We observed ictal focal beta activity as the predominant seizure pattern in a patient with refractory status epilepticus. Continuous left temporal beta activity clinically correlated with complex partial semiology on video-EEG.     

Three Epileptic Patients Suffering from Periods of Frequent Complex Partial Seizures and Diagnostic Criteria for Epileptic Status

Abstract: Presented here are three epileptic patients suffering from periods of frequent complex partial seizures. The importance of the following two points for the diagnosis of epileptic status of complex partial seizure is stressed. The first is the importance of EEG examination for differentiation of such epileptic status from psychogenic attack and absence status. The second is the importance of disturbed consciousness lasting between seizures. Based on EEG and clinical findings in our three patients, it was concluded that two of the three patients suffered from epileptic status of complex partial seizure and that the condition in the remaining one patient could not be judged as epileptic status of complex partial seizure. Detailed clinical and electroencephalographic findings in previously reported seven patients suffering from status epilepticus of complex partial seizure were compared with those of our two patients. The seven cases out of nine patients had epileptiform EEG activities beginning with localized rhythmic activities. All of the nine patients showed marked motor manifestations during the complex partial seizure such as adversive movement and automatic behaviors. Such motor manifestations of complex partial seizure are very useful for confirming the initiation and termination of the seizure. When the frequency of complex partial seizure is markedly increased, it becomes difficult to detect the initiation and termination of each seizure, and the discontinuous form of status epilepticus of complex partial seizure passes into its continuous form.     

Nonconvulsive Status Epilepticus: High Incidence of Complex Partial Status

Nonconvulsive status epilepticus may be subdivided into generalized (absence) status and complex partial status. The latter is regarded as a rarity, whereas the former constitutes the dominant part of the hitherto reported cases. We report 10 consecutive cases of adult patients with nonconvulsive status epilepticus, all documented by ictal electroencephalographic (EEG) recordings. Five had a complex partial status; the origin of the complex partial status appeared to be frontal in four of these patients. Three had recurrent complex partial seizures with incomplete recovery between seizures, and two had more continuous symptoms. One of the latter exhibited neither motor phenomena nor automatisms. The effect of diazepam or clonazepam was immediate in all 10 cases though transient in eight. A lasting control of the status was not achieved in six patients until i.v. phenytoin was added. The difficulties in the differentiation between complex partial status and absence status despite ictal EEG recordings are discussed, illustrated by a case with seizure discharges of a focal onset which rapidly generalized. The study indicates that complex partial status may be more common and the clinical expressions of absence status more variable than hitherto recognized.     

Alzheimer's disease underlies some cases of complex partial status epilepticus.

Alzheimer's disease is a known risk factor for seizures, and age older than 60 years is a recognized risk factor for poor outcome from convulsive and nonconvulsive status epilepticus. The authors suspect that there may be a causal relationship between dementia pathology and the development and maintenance of refractory seizures. They report two selected patients with complex partial status epilepticus whose presentation and clinical course provide partial support for this hypothesis. Their methods include case reports with clinical, EEG, imaging, and pathologic correlations. The patients were 70 and 85 years of age. Both had central and peripheral brain atrophy on imaging studies (with some regions that were affected more than others), left temporal seizure foci corresponding to areas of greatest cortical atrophy, and early presentation with inhibitory epileptic symptoms (aphasia), with evolution to complex partial status epilepticus. Pathologic confirmation of Alzheimer's disease was obtained in one patient who had not been diagnosed previously. It involved maximally the cortex underlying the seizure focus. A diagnosis of probable Alzheimer's disease was established in the other patient. Alzheimer's disease may be causal in some cases of complex partial status epilepticus. Additional observations in support of this hypothesis are needed.     

Aphasia as the Sole Manifestation of Simple Partial Status Epilepticus

Aphasia due to simple partial status epilepticus is rare, particularly in the absence of a seizure history. No previous report describes acute aphasia as the sole clinical manifestation of EEG-monitored status epilepticus, with prompt resolution with treatment. We report a 45-year-old man with a left temporal glioblastoma who acutely developed a global aphasia, during which an EEG revealed continual repetitive sharp waves emanating from the left hemisphere. After injection of i.v. diazepam, the EEG seizure activity ceased, and the patient's language output returned to preseizure levels.     

Nonconvulsive Status Epilepticus in Adults: Thirty-Two Consecutive Patients from a General Hospital Population

We studied all adult patients who between 1984 and 1989 were initially diagnosed at our hospital as having nonconvulsive status epilepticus. Thirty-two patients fulfilled the criteria, which included ictal EEG recordings. The annual incidence was 1.5 in 100,000 inhabitants. The median age at onset of status was 51 years. Ten patients had status as their first epileptic manifestation, but most patients had a previous history of epilepsy. Median duration of epilepsy at onset of status was 4 years. Fourteen patients had focal ictal seizure activity on EEG and thus met the criteria for complex partial status. Eighteen patients had generalized seizure activity on EEG, but only 6 of these had a history of absence epilepsy or juvenile myoclonic epilepsy. None had Lennox-Gastaut syndrome. The clinical features of status in the remaining 12 patients were in some respects similar to those of the patients with complex partial status. We hypothesize that the EEG seizure activity in these patients may have been generalized from an initial focus.     

Genetic mutations associated with status epilepticus

This paper reports the results of a preliminary search of the literature aimed at identifying the genetic mutations reported to be strongly associated with status epilepticus. Genetic mutations were selected for inclusion if status epilepticus was specifically mentioned as a consequence of the mutation in standard genetic databases or in a case report or review article. Mutations in 122 genes were identified. The genetic mutations identified were found in only rare conditions (sometimes vanishingly rare) and mostly in infants and young children with multiple other handicaps. Most of the genetic mutations can be subdivided into those associated with cortical dysplasias, inborn errors of metabolism, mitochondrial disease, or epileptic encephalopathies and childhood syndromes. There are no identified ‘pure status epilepticus genes’. The range of genes underpinning status epilepticus differs in many ways from the range of genes underpinning epilepsy, which suggests that the processes underpinning status epilepticus differ from those underpinning epilepsy. It has been frequently postulated that status epilepticus is the result of a failure of ‘seizure termination mechanisms’, but the wide variety of genes affecting very diverse biochemical pathways identified in this survey makes any unitary cause unlikely. The genetic influences in status epilepticus are likely to involve a wide range of mechanisms, some related to development, some to cerebral energy production, some to diverse altered biochemical pathways, some to transmitter and membrane function, and some to defects in networks or systems. The fact that many of the identified genes are involved with cerebral development suggests that status epilepticus might often be a system or network phenomenon. To date, there are very few genes identified which are associated with adult-onset status epilepticus (except in those with preexisting neurological damage), and this is disappointing as the cause of many adult-onset status epilepticus cases remains obscure. It has been suggested that idiopathic adult-onset status epilepticus might often have an immunological cause but no gene mutations which relate to immunological mechanisms were identified. Overall, the clinical utility of what is currently known about the genetics of status epilepticus is slight and the findings have had little impact on clinical treatment despite what has been a very large investment in money and time. New genetic technologies may result in the identification of further genes, but if the identified genetic defects confer only minor susceptibility, this is unlikely to influence therapy. It is also important to recognize that genetics has social implications in a way that other areas of science do not.This article is part of a Special Issue entitled “Status Epilepticus”.     

Can absence status epilepticus be of frontal lobe origin?

Five women with an unclassifiable nonconvulsive status epilepticus (NCSE) characterized by young age at onset, prolonged confusions, focal motor seizures, and both generalized spike-and-wave discharges and focal epileptic discharges on the EEG were studied with video-EEG monitoring. Electrographically, the NCSE originated from the left frontal lobe in 4 patients, and the left hemisphere with multifocal seizure discharges in 1 patient. Focal motor seizures seemed to originate from the left hemisphere in all 5 patients, particularly from its anterior part in 3 of them. Results show that the NCSE is complex partial status epilepticus of frontal lobe origin electroclinically mimicking absence status epilepticus once it reaches a full-blown phase.     

Serum prolactin response to metoclopramide during status epilepticus.

Transient elevation of serum prolactin frequently follows generalised tonic-clonic and complex partial seizures. However, the levels of prolactin during status epilepticus are not increased above the normal range. Exhaustion of central prolactin supplies has been proposed as a possible mechanism for the absence of prolactin increase during status epilepticus. To test this hypothesis we injected intravenous metoclopramide (10 mg) in eight consecutive patients with status epilepticus. One patient had generalised tonic-clonic status epilepticus. Seven patients had EEG-verified non-convulsive status epilepticus, consisting of one typical absence status, one atypical absence status and five complex partial status epilepticus. Metoclopramide raised the mean (SD) prolactin levels at least five-fold in all patients, from 5.8 (8.0) micrograms/l to 87.0 (39.0) micrograms/l, within 60 minutes after the injection. Thus the mechanism for low prolactin values in status epilepticus is not cellular depletion of stored prolactin, but more likely an altered regulation, presumably induced by prolonged seizure activity.     

Successful neurosurgical treatment of childhood complex partial status epilepticus with focal resection

The treatment of complex partial status epilepticus continues to be controversial, especially with regard to the intensity of the treatment. Medical therapy and drug-induced coma are sometimes required. Rarely this may not be effective. A healthy 4-year old girl was first seen in complex partial status epilepticus. She had a 1-year history of cryptogenic partial-onset seizures. Detailed magnetic resonance imaging (MRI) studies were normal. Her course was refractory to multiple medical therapies and multiple subpial transection (MST). An urgent epilepsy surgery evaluation resulted in a focal cortical resection being performed over the right mesial parietal region with resultant seizure freedom and no significant neurologic deficit 2 years later. This patient illustrates the need to consider occult focal cortical dysplasia as a cause of nonconvulsive status epilepticus (NCSE) in children, and if it is not responsive to medical management, the utility of performing an urgent epilepsy surgery evaluation.     

États de mal épileptiques non convulsifs

Non convulsive confusional status epilepticus is classically divided on the basis of the ictal EEG into absence status (AS) and complex partial status epilepticus (CPSE). The clinical presentation is often insufficient to establish diagnosis and emergency EEG is required. AS is a polymorphic condition that can complicate many epileptic syndromes. In half of cases, confusion of varying intensity is associated with bilateral periocular myoclonias. Clinical and EEG normalization is obtained after intravenous benzodiazepine injection. From a nosographic point of view, four types of AS may be recognized. Typical AS occurs as part of an idiopathic generalized epilepsy. Atypical AS occurs in patients with symptomatic or cryptogenic generalized epilepsies. “De novo” AS of late onset is characterized by toxic or metabolic precipitating factors in middle-aged subjects with no previous history of epilepsy. AS with focal characteristics occurs in subjects with a preexisting or newly developing partial epilepsy, most often of extratemporal origin. Most cases are transitional forms between these four entities. CPSE is characterized by continuous or rapidly recurring complex partial seizures which may involve temporal and/or extratemporal regions. Cyclic disturbance of consciousness is characteristic of CPSE of temporal lobe origin, which requires vigorous treatment to prevent recurrence or cognitive sequelae. CPSE of frontal lobe origin is a diagnostic challenge: it is rare, the symptoms are unusual, and extensive documentation is required. A focal, frontal lesion is discovered in one third of cases.     

Unilateral Limbic Epileptic Status Activity: Stereo EEG, Behavioral, and Cognitive Data

We report data from four patients with unilateral epileptiform status activity within different structures of the temporal lobe, recorded during stereoelectroencephalographic presurgical evaluation. The ictal clinical symptoms accompanying neocortical and mesiobasal limbic discharges (two patients with complex partial status epilepticus) consisted of various psychosensory and vegetative signs, which can be understood on the basis of the spatiotemporal analysis of the discharges. The other two patients with circumscribed long-lasting mesiobasal limbic epileptiform activity represent unilateral pure limbic status epilepticus and were characterized by a marked behavioral syndrome (with stickiness, aggressivity, etc.) and a monomorphic gustatory aura continua, respectively. The latter patient, with left hippocampal discharges of nearly continuous epileptiform character, was also assessed with tachistoscopic tasks. Performance revealed cognitive impairment only in the epileptically discharging hemisphere and in dependence on the quality of the EEG pattern. After unilateral selective amygdalohippocampectomy, the two patients with limbic status epilepticus were seizure free and had markedly improved behavior and cognitive functions. Thus, patients with nonconvulsive status epilepticus represent an ideal model, although rare, to correlate behavior alterations and brain dysfunction.     

Nonconvulsive status epilepticus: Epilepsy Research Foundation workshop reports.

In April 2004, a group of physicians with an interest in nonconvulsive status epilepticus representing a spectrum of opinion met in Oxford, sponsored by the Epilepsy Research Foundation (a charitable organization), to discuss and debate the definition, diagnosis and treatment of nonconvulsive status epilepticus. We felt that such a meeting would be useful, as nonconvulsive status epilepticus is a subject that provokes strong reactions, perhaps largely due to the relative lack of evidence and the surfeit of opinion. The meeting was arranged such that there were formal talks followed by a discussion led by one of the attendees. We present here the extended abstracts of the main talks with the points raised by the discussants. Despite disagreements on certain issues there was much in the way of consensus. First, it was agreed that nonconvulsive status epilepticus is a term that covers a range of disparate conditions with varying prognoses and treatments. The agreed definition was thus suitably vague, A. Secondly, it was agreed that even within a specific condition (e.g. complex partial status epilepticus), the prognosis and treatment depends upon the context in which the condition occurs (e.g. in the critically ill, in coma, in the A and in people with prior epilepsy). Perhaps, most importantly it was agreed that we lacked good clinical data, and the challenge was to design good studies for a condition that is underrecognised and often difficult to diagnose.     

Complex partial status epilepticus of extratemporal origin: report of a case

A 28-year-old woman with no history of seizure was 7 months pregnant when she developed a prolonged complex partial status epilepticus (CPSE) organized in recurrent complex partial seizures of occipital origin, which was ascertained by the presence of elementary visual hallucinations and nystagmus heralding the attacks. EEG demonstrated recurrent seizures starting from the right occipital area. This especially refractory case of CPSE resolved after treatment with antiepileptic drugs and termination of pregnancy by cesarean section.     

FDG-PET in the diagnosis of complex partial status epilepticus originating from the frontal lobe

Complex partial status epilepticus of frontal origin can manifest as nonconvulsive behavioral symptoms that mimic psychiatric illness and, thus, may elude timely diagnosis. The diagnosis can be further delayed by absence of ictal activity on scalp electroencephalography when the ictal origin is orbitofrontal or mesial frontal. We describe the case of a 51-year-old woman with clinically subtle complex partial status epilepticus of left orbitofrontal origin, lacking any clear ictal pattern on the electroencephalogram, who was finally diagnosed using positron emission tomography with [(18)F]fluorodeoxyglucose (FDG-PET). Subsequent FDG-PET following 5 days of oxcarbazepine therapy demonstrated resolution of the left orbitofrontal hypermetabolic focus. FDG-PET is a potentially useful modality for diagnosing nonconvulsive status epilepticus that is not evident on electroencephalography.     

Hypersalivation in temporal lobe epilepsy

PURPOSE: We sought to determine whether hypersalivation helps lateralize seizure onset during complex partial seizures of temporal lobe origin. Several clinical signs, which help lateralize seizure onset, have been reported in temporal lobe epilepsy (TLE). Increased salivation only occasionally has been reported as a manifestation of partial epilepsy. METHODS: Of 590 consecutive patients admitted for video-EEG monitoring, either as a part of a presurgical evaluation of medically intractable epilepsy or for diagnosis and clarification of their paroxysmal symptoms, we identified 10 patients with ictal hypersalivation as a prominent manifestation of complex partial seizures. We reviewed the clinical features, scalp-sphenoidal video-EEG monitoring, intracarotid amytal (Wada) testing, hippocampal volumetric magnetic resonance imaging (MRI), and fluorodeoxyglucose-positron emission tomography (FDG-PET) scans of these patients. RESULTS: Of the 10 patients with ictal hypersalivation, seven patients had nondominant/right TLE, and three patients had dominant/left TLE. All patients had hippocampal atrophy on volumetric MRI. Eight of the 10 patients underwent standard temporal lobectomy with amygdalohippocampectomy (six right, two left). All of the operated-on patients had a seizure-free (Engel class I) outcome, and their increased salivation resolved. Two patients, who did not undergo surgical treatment, continue to have complex partial seizures with increased salivation. CONCLUSIONS: We conclude that increased salivation as a prominent ictal finding in complex partial seizures of temporal lobe origin is more likely to be of nondominant temporal lobe origin. Further studies with larger numbers of patients are needed to replicate this finding.     

Diffusion-weighted imaging and status epilepticus during vagus nerve stimulation

PURPOSE: Transient abnormalities have been reported on diffusion-weighted imaging (DWI) during status epilepticus. Vagus nerve stimulation (VNS) is a therapy for epilepsy that has previously demonstrated alteration in regional cerebral blood flow on functional neuroimaging. We describe the peri-ictal DWI abnormalities in a patient with status epilepticus. METHODS: A 21-year-old woman with pharmacoresistant localization-related epilepsy was treated with VNS and underwent brain magnetic resonance imaging (MRI) with DWI for clinical purposes. RESULTS: Transient and reversible hyperintense signal abnormalities were noted on DWI at the site of seizure onset, in addition to the thalamus and midbrain bilaterally. A concomitant decrease in the apparent diffusion coefficient mimicked ischemia, yet complete clinical, and electrographic resolution occurred following successful termination of status. CONCLUSIONS: High-energy brain MRI sequences using DWI were safely performed in our epilepsy patient with a vagus nerve stimulator who experienced status epilepticus. This case highlights the bilateral and robust involvement of subcortical structures present immediately following status epilepticus. Additionally, bilateral abnormalities in the thalamus and midbrain in addition to the region of seizure origin, were observed in our patient implanted with a vagus nerve stimulator. Modulation of regional cerebral blood flow is one potential mechanism of action for VNS in humans; therefore, these regions of involvement could reflect the effects of status epilepticus, activation or facilitation by VNS, or both.     

Schizophrenia following new-onset refractory status epilepticus secondary to antiphospholipid syndrome

New-onset refractory status epilepticus (NORSE) is a drug-resistant status epilepticus that often has a catastrophic outcome. Our patient was diagnosed with NORSE and had an EEG reading that showed status epilepticus persisting for 8 months in general anesthesia. After autoimmune workup showed positive antiphospholipid antibodies, his seizure was controlled, and he was discharged with good condition apart from moderate cognitive impairment. However, he later developed schizophrenia. Although psychiatric disorders have been associated with antiphospholipid syndrome, to the best of our knowledge, it has not been reported to be associated with status epilepticus. We recommend vigilance of psychological complications of refractory status epilepticus’ patients for early psychiatric referral, diagnosis, and treatment.

New-onset refractory status epilepticus (NORSE) is a syndrome of new-onset drug-resistant status epilepticus that often has a catastrophic outcome. Epilepsy is usually associated with psychiatric disorders of different manifestations of which psychosis is an example.1 However, not much is found in the literature review regarding psychiatric disorders following NORSE although a recent study concluded 32% of NORSE patients ended up with altered behavioral states like aggression.2 Schizophrenia following NORSE like in the rare presentation of this case has not been reported in the literature review before, although an association between schizophrenia and autoimmune disorders like APS has been reported.3     

Prevalence of nonconvulsive status epilepticus in comatose patients

BACKGROUND: Nonconvulsive status epilepticus (NCSE) is a form of status epilepticus (SE) that is an often unrecognized cause of coma. OBJECTIVE: To evaluate the presence of NCSE in comatose patients with no clinical signs of seizure activity. METHODS: A total of 236 patients with coma and no overt clinical seizure activity were monitored with EEG as part of their coma evaluation. This study was conducted during our prospective evaluation of SE, where it has been validated that we identify over 95% of all SE cases at the Medical College of Virginia Hospitals. Only cases that were found to have no clinical signs of SE were included in this study. RESULTS: EEG demonstrated that 8% of these patients met the criteria for the diagnosis of NCSE. The study included an age range from 1 month to 87 years. CONCLUSION: This large-scale EEG evaluation of comatose patients without clinical signs of seizure activity found that NCSE is an underrecognized cause of coma, occurring in 8% of all comatose patients without signs of seizure activity. EEG should be included in the routine evaluation of comatose patients even if clinical seizure activity is not apparent.     

Status epilepticus with confusional symptomatology]

Non-convulsive confusional status epilepticus (NCSE) is classically separated into two forms on the basis of the ictal EEG, i.e., absence status (AS) and complex partial status epilepticus (CPSE). The diagnosis is difficult on the basis of clinical semiology alone, and requires emergency EEG investigation. Absence status, or 'petit mal' status, is a polymorphic condition that can complicate many epileptic syndromes, and is the most frequently encountered form of NCSE. It is characterized by confusion of varying intensity, associated in 50% of cases with bilateral periocular myoclonias. The EEG shows ictal generalized paroximal activity; normalization is obtained after benzodiazepine injection. In AS, there is a significant nosographic heterogeneity. Four groups can be distinguished: i) typical AS occurs in the context of a generalized idiopathic epilepsy; ii) atypical AS occurs in patients with symptomatic or cryptogenic generalized epilepsies; iii) 'de novo' AS (of late onset) is characterized by toxic or metabolic precipitating factors in middle-aged subjects with no previous history of epilepsy; iv) AS with focal characteristics occurs in subjects with a pre-existing or newly diagnosed partial epilepsy, mostly of extra-temporal origin. The majority of cases are in fact transitional forms between these four groups. CPSE is characterized by continuous or rapidly recurring complex partial seizures which may involve temporal and/or extratemporal regions. Cyclic disturbance of consciousness is characteristic of CPSE of temporal lobe origin, which requires vigorous treatment to prevent recurrence or cognitive sequelae. CPSE of frontal lobe origin is a diagnostic challenge: it is rare, the symptoms are unusual, and the patients should be documented extensively. A focal frontal lesion is revealed in one-third of cases.