Persistent nonconvulsive status epilepticus after the control of convulsive status epilepticus

The current state of treatment of status epilepticus

There have been many important developments in the diagnosis and treatment of status epilepticus in the recent past. Earlier treatment, including at home by caregivers and in the field by paramedics, has been shown to be safe and effective. Rapid-acting anesthetic agents, such as midazolam and propofol, are being used more often for refractory status epilepticus, though clinical trials are lacking. Nonconvulsive status epilepticus is being considered and recognized more often, including in ambulatory patients with a confusional state, after convulsive status epilepticus, and in critically ill patients. Modern technology and continuous digital electroencephalogram (EEG) recordings have taught us many things, but have raised at least as many questions. Much work needs to be done regarding the significance of certain EEG patterns (particularly periodic discharges) and when and how to treat them. This article reviews these issues, concentrating on recent advances and practical issues related to the clinical care of patients with status epilepticus.

Status Epilepticus

Status epilepticus (SE) is a common neurologic emergency with a high mortality. Immediate recognition and rapid treatment are essential. After initial stabilization of airway and circulation, the patient should be treated as soon as possible with an intravenous (IV) benzodiazepine, followed immediately by IV fosphenytoin. If SE persists, general anesthesia should be initiated, with intubation and cardiac monitoring. Electroencephalogram must also be monitored to ensure suppression of all seizures. Etiology of SE should be assessed through history, examination, blood tests, and brain imaging.

Treatment of refractory status epilepticus with pentobarbital, propofol, or midazolam: a systematic review

BACKGROUND

New continuous infusion antiepileptic drugs (cIV-AEDs) offer alternatives to pentobarbital for the treatment of refractory status epilepticus (RSE). However, no prospective randomized studies have evaluated the treatment of RSE. This systematic review compares the efficacy of midazolam (MDL), propofol (PRO), and pentobarbital (PTB) for terminating seizures and improving outcome in RSE patients.

METHODS

We performed a literature search of studies describing the use of MDL, PRO, or PTB for the treatment of RSE published between January 1970 and September 2001, by using MEDLINE, OVID, and manually searched bibliographies. We included peer-reviewed studies of adult patients with SE refractory to at least two standard AEDs. Main outcome measures were the frequency of immediate treatment failure (clinical or electrographic seizures occurring 1 to 6 h after starting cIV-AED therapy) and mortality according to choice of agent and titration goal (cIV-AED titration to "seizure suppression" versus "EEG background suppression").

RESULTS

Twenty-eight studies describing a total of 193 patients fulfilled our selection criteria: MDL (n = 54), PRO (n = 33), and PTB (n = 106). Forty-eight percent of patients died, and mortality was not significantly associated with the choice of agent or titration goal. PTB was usually titrated to EEG background suppression by using intermittent EEG monitoring, whereas MDL and PRO were more often titrated to seizure suppression with continuous EEG monitoring. Compared with treatment with MDL or PRO, PTB treatment was associated with a lower frequency of short-term treatment failure (8 vs. 23%; p < 0.01), breakthrough seizures (12 vs. 42%; p < 0.001), and changes to a different cIV-AED (3 vs. 21%; p < 0.001), and a higher frequency of hypotension (systolic blood pressure <100 mm Hg; 77 vs. 34%; p < 0.001). Compared with seizure suppression (n = 59), titration of treatment to EEG background suppression (n = 87) was associated with a lower frequency of breakthrough seizures (4 vs. 53%; p < 0.001) and a higher frequency of hypotension (76 vs. 29%; p < 0.001).

CONCLUSIONS

Despite the inherent limitations of a systematic review, our results suggest that treatment with PTB, or any cIV-AED infusion to attain EEG background suppression, may be more effective than other strategies for treating RSE. However, these interventions also were associated with an increased frequency of hypotension, and no effect on mortality was seen. A prospective randomized trial comparing different agents and titration goals for RSE with obligatory continuous EEG monitoring is needed.

Diagnosis and treatment of nonconvulsive status epilepticus

Nonconvulsive status epilepticus (SE) is not uncommon and comprises at least one-third of all cases of SE. However, nonconvulsive SE consists of very different syndromes, a common feature being the difficulty in making the diagnosis. In this review, nonconvulsive SE is divided into typical absence SE, complex partial SE, nonconvulsive SE in patients with learning difficulties (including electrical SE during sleep, atypical absence SE and tonic SE), and nonconvulsive SE in coma. These conditions have different prognoses and treatments. The diagnosis of these conditions is critically dependent on EEG. When the EEG demonstrates typical ictal patterns, the diagnosis is usually straightforward. However, in many circumstances the EEG has to be differentiated from encephalopathic patterns, and this differentiation can prove troublesome, although the clinical and electrographic response to treatment can prove helpful. Nonconvulsive SE in patients with learning difficulties possibly provides the greatest diagnostic difficulty; the clinical presentation can be subtle resulting in the diagnosis being frequently missed. Whether the neuronal damage that occurs in convulsive SE and in animal models of limbic SE also occurs in nonconvulsive SE in humans is still a matter of debate. There are critical differences between the animal models and the human condition. Indeed, the prognosis of nonconvulsive SE is usually dependent on the underlying aetiology rather than the persistence of electrographic discharges. Because of these doubts, a more conservative approach to the treatment of particular types of nonconvulsive SE (those with a better prognosis) has been taken in this article. Thus, in most instances, oral benzodiazepines for the treatment of typical absence SE and complex partial SE are recommended. In some circumstances intravenous medication is necessary, but in neither condition is anaesthetic coma recommended. This contrasts with nonconvulsive SE in coma in which a more aggressive approach is suggested. Until there are more relevant animal models, and controlled trials of conservative versus more aggressive treatment, treatment regimens for nonconvulsive SE will remain largely speculative.

Status epilepticus and acute serial seizures in children

Status epilepticus is defined as a seizure that persists for a sufficient length of time or is repeated frequently enough to produce a fixed and enduring epileptic condition of 30 minutes or longer. Status epilepticus is a life-threatening condition that often occurs in children. The degree of mortality and neurologic morbidity, as well as the risk for recurrence, is highly dependent on the etiology and duration of the seizures. Although much has been written about pediatric status epilepticus, many issues remain unresolved. A better understanding of the different types of seizures and their etiologies may help in the prevention and treatment of status epilepticus. The vast extent of status epilepticus in both children and adults mandates that new options for prevention and treatment be given a close scrutiny and high priority. This article will review the most current information on convulsive and nonconvulsive status epilepticus, including the potential for neurologic damage, changes in magnetic resonance imaging after status epilepticus, risk for recurrence, and current treatment options available for treating status epilepticus in children.

[Pseudoperiodic and paroxysmal electroencephalographic activities]

Periodic and paroxysmal EEG patterns are frequent and easily recognized. They often correlate with particular neurological or systemic conditions. We propose a reclassification and critical examination of these periodic EEG patterns by reviewing the original work presented by J. Gaches in this journal some thirty years ago. Periodic EEG activity is still classified by its localisation--generalised or focal--and by its periodicity--long or short. Periodic long-interval diffuse paroxysmal patterns are reported with rare pathologies such as SSPE, trypanosomiasis or intoxication with phencyclidine. Suppression bursts (SB) may be found in two main situations post-anoxic encephalopathies and drug-induced comas. Ohtahara syndrome is a very rare childhood epileptic syndrome with SB. Periodic short-interval diffuse pattern have been reported in Creutzfeldt-Jakob disease but also in toxic encephalopathies, such as lithium intoxication or as recently reported in acute Cefepime intoxication as well as with metabolic encephalopathies and rarely during AIDS. Periodic lateralized epileptiform discharges (PLEDs) have been classified according to their morphology and the associated condition (epileptic seizures, subtle status, "vascular" seizure). The principal etiology is cerebro-vascular disease and herpes encephalitis but it has also been reported in several other neurological diseases.

Status epilepticus in older patients: epidemiology and treatment options

Status epilepticus (SE) is a medical and neurological emergency that has been associated with significant morbidity and mortality. The most widely accepted definition of SE is more than 30 minutes of either continuous seizure activity, or intermittent seizures without full recovery of consciousness between seizures. SE is a major clinical concern in the elderly population, both because it has increased incidence in the elderly compared with the general population, and because of concurrent medical conditions that are more likely to complicate therapy and worsen prognosis in elderly individuals. The incidence of SE in the elderly is almost twice that of the general population at 86 per 100,000 per year. With the anticipated growth of the elderly population, SE is likely to become an increasingly common problem facing clinicians, and an important public health issue. The elderly have the highest SE-associated mortality of any age group at 38%, and the very old elderly (>80 years of age) have a mortality of at least 50%. Acute or remote stroke is the most common aetiology of SE in the elderly. Nonconvulsive SE (NCSE) has a wide range of clinical presentations, ranging from confusion to obtundation. It occurs commonly in elderly patients who are critically ill and in the setting of coma. Electroencephalogram is the only reliable method of diagnosing NCSE. The goal of treatment for SE is rapid cessation of clinical and electrical seizure activity. Most treatment protocols call for the immediate administration of an intravenous benzodiazepine, followed by phenytoin or fosphenytoin. Recent studies suggest that when this initial treatment of SE fails, little is gained by using additional standard drugs. General anaesthetic agents (such as pentobarbital, midazolam, or propofol) should be expeditiously employed, although these treatments have their own potential complications. Intravenous valproic acid is a recent addition to the armamentarium of drugs for the treatment of SE, with a low risk of hypotension, respiratory depression and hypotension, making it a potentially useful drug for the treatment of SE in the elderly. However, further information is needed to establish its role in the overall treatment of SE.

Long-term EEG monitoring: a clinical approach to electrophysiology

Long-term electroencephalographic monitoring (LTM) is the capability of recording the EEG over long periods of time and not a specific duration. Prolonged EEG recording is used primarily for epilepsy monitoring, but LTM is also used in the intensive care unit, the operating room, and in the emergency department. The purpose of LTM is to expand the limited time sampling associated with shorter "routine" EEG recording. Audiovisual monitoring may also be used in conjunction with LTM to evaluate simultaneously a specific clinical behavior that may or may not be associated with EEG alteration. This is typically performed in a hospital setting for safety and ancillary testing purposes. LTM is used most frequently in the diagnosis and management of seizures and "spells," but has also gained wider application in the evaluation of sleep disorders, cerebrovascular disease, psychiatric conditions, and movement disorders. Computer-assisted LTM systems that process, analyze, compress, and store data digitally have become widely available in clinical practice both in the hospital as well as outside the hospital when the patient is ambulatory.

The etiology and diagnosis of status epilepticus

Status epilepticus (SE) is a common, serious, potentially life-threatening, neurologic emergency characterized by prolonged seizure activity. Generalized convulsive status epilepticus (GCSE) is the most widely recognized form of SE. Direct consequences of convulsive movements from SE can result in injury to the body and brain. Nonconvulsive status epilepticus (NCSE) is underrecognized, with controversy surrounding the consequences and treatment. High mortality rates with GCSE have been noted in the past. New treatments for SE are emerging with new parenteral drug formulations as well as new agents for refractory SE, offering an opportunity to improve outcome. Special drug delivery systems, drug combinations, and neuroprotective agents that prevent the subsequent development of epilepsy may soon emerge as future options for treating SE.

Utility of electroencephalography in the pediatric emergency department

To assess the role of electroencephalography (EEG) in the pediatric emergency department, we reviewed the records of all patients having an EEG in the pediatric emergency department of our hospital between 1995 and 1997. EEG findings, clinical presentations, and follow-up data were analyzed, and patients were distributed into three groups according to clinical presentation: group 1 included patients with new-onset seizures, group 2 included patients with known epilepsy presenting with worsening seizures and altered mentation, and group 3 comprised patients with acute confusional states. Overall, 56 patients with 57 EEGs were included. In group 1 (n = 36), 20 (55.6%) had an abnormal EEG. The risk of recurrence was much higher in children with abnormal EEGs (80% vs. 31%) (P < .01). In retrospect, among all of the patients receiving the diagnosis of epilepsy, 76% had an abnormal emergency department EEG. Four in group 2 (n = 14) and one in group 3 (n = 7) were proven to have nonconvulsive status epilepticus and were treated accordingly. No patients in group 1 had nonconvulsive status epilepticus. Ongoing seizures were promptly excluded in the remainder. The EEG directly contributed to the diagnosis in 84% of all referrals in the pediatric emergency department, either being abnormal and leading to a diagnosis of a seizure disorder or confirming low suspicion for seizures. Thus, a prompt EEG should be considered in children with new-onset seizures and unexplained altered consciousness.

Emergency department management of patients with seizures: a multicenter study

OBJECTIVES

Patients with seizure disorders are common in the emergency department (ED), yet little is known regarding the management of these patients. This study was performed to define the frequency of patients with seizure disorders in the ED patient population and to determine possible seizure etiologies, characteristics of diagnostic activities, treatments, and dispositions.

METHODS

Twelve EDs monitored all patients with a chief complaint related to seizure disorders presenting over 18.25 days (5% of the calendar year) in late 1997. Retrospective chart review was used to gather specific data regarding these consecutive cases.

RESULTS

Of the 31,508 patients who presented to these 12 EDs during the study period, 368 (1.2%) had complaints related to seizures. Three hundred sixty-two charts were available for analysis and make up the study population. Two hundred fifty-seven (71%) utilized emergency medical services (EMS) for transport and care. Advanced care, including intravenous access, laboratory work, cardiac monitoring, or oxygen administration, was utilized in 304 (84%) patients. Antiepileptic drugs were given in 199 (55%) patients. Ethanol withdrawal or low antiepileptic drug levels were implicated as contributing factors in 177 (49%) of patients. New-onset seizures were thought to be present in 94 (26%) patients. Status epilepticus occurred in only 21 (6%) patients. Ninety-eight (27%) of all patients were admitted to the hospital.

CONCLUSIONS

Patients with presenting complaints related to seizures are frequent in the ED population and make considerable demands on EMS and ED resources. Six percent of patients with seizure-related presentations were in status epilepticus and more than a fourth of all patients required hospitalization.

Treatment of status epilepticus

The approach to treatment of status epilepticus has changed because of the demonstration of decreased mortality with rapid intervention, completion of a randomized, double-blind VA Cooperative study comparing first-line agents, and further understanding of the pathophysiologic changes discovered in experimental animal studies. This article reviews the treatments of generalized convulsive status epilepticus in the prehospital, emergency department, and intensive care unit settings.

Seizures in the adult intensive care unit

Seizures are a common occurrence in the intensive care unit (ICU). The presentation of seizures is usually as focal or generalized motor convulsions, but other seizure types may occur. Etiologies of the seizures are typically secondary either to primary neurologic pathology or a consequence of critical illness and clinical management. Particularly important as precipitants of seizures are hypoxia/ischemia, drug toxicity, and metabolic abnormalities. It is important to properly diagnose the seizure type and its cause to ensure appropriate therapy. Most seizures occur singly, and recurrence is usually prevented with initiation of anticonvulsant therapy. However, status epilepticus may develop, which requires emergent treatment before irreversible brain injury occurs. Treatment with anticonvulsants is not without untoward risks, however, and primary toxicities of these agents is reviewed. After traumatic head injury, brain surgery, or cerebrovascular accidents, many patients are at risk for seizures. Current data on the benefits of prophylactic therapy for such patients is also reviewed.

[Diagnosis of status epilepticus by continuous EEG monitoring in a neurointensive care unit]

Continuous EEG monitoring use has documented a surprisingly high incidence of convulsive and non-convulsive status epilepticus in patients with acute brain injuries. Seizures are the cause of secondary insult. Many problems may be encountered during EEG recording, such as electrical interferences and artefacts arising from the patient. To minimise these problems, we suggest the following: train the bedside nurse, make a library of the artefacts, have the EEG technologist check electrodes and establish low impedance, have the electroencephalographer examine the EEG, correlate the activity and movements of the patient. In the diagnosis and the management of convulsive and non-convulsive status epilepticus, the value of continuous EEG monitoring appears to be established.

No, some types of nonconvulsive status epilepticus cause little permanent neurologic sequelae (or: "the cure may be worse than the disease")

Nonconvulsive status epilepticus (NCSE) is characterized by a cognitive or behavioral change which lasts for at least 30 minutes, with EEG evidence of seizures. Although there is little argument that generalized nonconvulsive status epilepticus (GNSE) does not cause lasting deficits, there is still debate regarding the morbidity of complex partial status epilepticus (CPSE). Because the EEG is used for diagnosis, a strong argument can be made that NCSE is significantly under-recognized and diagnosed. Furthermore, since the documented cases of permanent neurologic sequelae are few, the potential permanent morbidity from CPSE may be significantly exaggerated. The literature indicates that comatose patients have a poor prognosis largely as a result of comorbid conditions and coma, whereas lightly obtunded or slightly confused patients with NCSE have little or no sequelae. Patients with NCSE may suffer (hypotension and respiratory suppression) from iatrogenic 'aggressive' treatment with intravenous anti-epileptic drugs (IV-AEDs), and the findings in the literature indicate that subjects treated with benzodiazepines may have a worse prognosis. The clinician must balance the potential but rare neurologic morbidity associated with NCSE against the not infrequent morbidity caused by IV-AEDs. Better stratification of the level of consciousness and comorbid conditions is needed when evaluating outcomes so as to clearly distinguish among the deficits due to: comorbid conditions; the effects of treatment and the effects of status epilepticus (SE) proper.

Presentation, evaluation, and treatment of nonconvulsive status epilepticus

Nonconvulsive status epilepticus (NCSE) is much more common than is generally appreciated. It is certainly underdiagnosed, but its presentation is protean. Diagnostic criteria and treatment are controversial. Absence status is characterized by confusion or diminished responsiveness, with occasional blinking or twitching, lasting hours to days, with generalized spike and slow wave discharges on the EEG. Complex partial status consists of prolonged or repetitive complex partial seizures (with a presumed focal onset) and produces an "epileptic twilight state" with fluctuating lack of responsiveness or confusion. There is a clear overlapping of syndromes. Other confused, stuporous, or comatose patients with rapid, rhythmic, epileptiform discharges on the EEG may have "electrographic" status and should be considered in the same diagnostic category. NCSE typically occurs following supposedly controlled convulsions or other seizures, but with persistent neurologic dysfunction despite apparently adequate treatment. Confusion in the elderly or among emergency room patients is also a typical setting. The diagnosis of NCSE usually involves an abnormal mental status with diminished responsiveness, a supportive EEG, and often a response to anticonvulsant medication. All patients have clinical neurologic deficits, but the EEG findings and response to seizure medication are variable and are more controversial criteria. The response to drugs can be delayed for up to days. Experimental models and pathologic studies showing neuronal damage from status epilepticus pertain primarily to generalized convulsive status. Most morbidity from NCSE appears due to the underlying illness rather than to the NCSE itself. Some cases of prolonged NCSE or those with concomitant systemic illness, focal lesions, or very rapid epileptiform discharges may suffer more long-lasting damage. Although clinical studies show little evidence of permanent neurologic injury, the prolonged memory dysfunction in several cases and the similarities to convulsive status suggest that NCSE should be treated expeditiously. The diagnosis is important to make because NCSE impairs the patient's health significantly, and it is often a treatable and completely reversible condition.

The EEG in coma

The EEG allows insight into thalamocortical function in comatose patients when this is inaccessible clinically. A single EEG can help with broad diagnostic categorization whereas continuous or serial EEG provides monitoring for unstable and potentially treatable conditions and for monitoring the effects of therapy. The EEG plays a supplemental role in establishing the prognosis in disease states that are capable of causing neuronal death. The most prevalent and problematic of these conditions involves survivors of cardiac arrest who are initially in coma with intact brainstem reflexes. In such patients single EEGs are of 100% specificity for no possibility of recovery of consciousness only for essentially complete generalized suppression (<10 microV) after the first day of the arrest. Several other generalized patterns, including less marked suppression, burst-suppression, epileptiform activity, periodic complexes, and alpha-theta coma patterns, usually but not invariably indicate a poor outcome. Serial EEGs, continuous raw and automated "trending," testing of reactivity, and the inclusion of multiple variables hold promise for an improved role in the prognostic determination in these patients.

Assessment of inhibition and epileptiform activity in the septal dentate gyrus of freely behaving rats during the first week after kainate treatment

Mossy fiber reorganization has been hypothesized to restore inhibition months after kainate-induced status epilepticus. The time course of recovery of inhibition after kainate treatment, however, is not well established. We tested the hypothesis that if inhibition is decreased after kainate treatment, it is restored within the first week when little or no mossy fiber reorganization has occurred. Chronic in vivo recordings of the septal dentate gyrus were performed in rats before and 1, 4, and 7-8 d after kainate (multiple injections of 5 mg/kg, i.p.; n = 17) or saline (n = 11) treatment. Single and paired-pulse stimuli were used to assess synaptic inhibition. The first day after kainate treatment, only a fraction of rats showed multiple population spikes (35%), prolonged field postsynaptic potentials (76%), and loss of paired-pulse inhibition (29%) to perforant path stimulation. Thus, inhibition was reduced in only some of the kainate-treated rats. By 7-8 d after treatment, nearly all kainate-treated rats showed partial or full recovery in these response characteristics. Histological analysis indicated that kainate-treated rats had a significant decrease in the number of hilar neurons compared to controls, but Timm staining showed little to no mossy fiber reorganization. These results suggest that a decrease in synaptic inhibition in the septal dentate gyrus is not a prerequisite for epileptogenesis and that most of the recovery of inhibition occurs before robust Timm staining in the inner molecular layer.

Epidemiology and evidence for morbidity of nonconvulsive status epilepticus

Convulsive status epilepticus (SE) is convincingly related to serious morbidity and mortality and well recognized as a medical emergency, but prompt diagnosis and treatment of patients with nonconvulsive status epilepticus (NCSE) is often not emphasized because its consequences are thought to be benign. Nonconvulsive status epilepticus has been considered a relatively benign entity because it does not produce the adverse systemic consequences of convulsive status epilepticus, such as hyperthermia, acidosis, hyperkalemia, pulmonary compromise, or cardiovascular collapse. However, recent reports indicate that NCSE is not so benign. There are two major forms of NCSE, absence status epilepticus and complex partial status epilepticus. Typical absence status epilepticus does not appear to have very serious consequences and may be a type of "inhibitory" seizure, but complex partial status epilepticus has been associated with serious morbidity and mortality. Despite not causing the systemic physiologic or metabolic derangements seen with convulsive SE, complex partial status epilepticus is still associated with the two other major factors correlated with poor outcomes in convulsive SE: 1) neuronal damage from abnormal electrical activity and 2) the interaction of acute neurologic disorders, such as stroke, that may precipitate SE. Other similar epileptiform encephalopathies such as "subclinical," "electroencephalographic," "nontonic-clonic," and "subtle" SE have not been as well studied as NCSE but pose similar issues. Early diagnosis and aggressive intervention have proven the best means of averting adverse outcomes in patients with convulsive SE. The diagnosis and treatment of NCSE, particularly complex partial status epilepticus, merit similar emphasis and attention.

Assessing the outcomes in patients with nonconvulsive status epilepticus: nonconvulsive status epilepticus is underdiagnosed, potentially overtreated, and confounded by comorbidity

Nonconvulsive status epilepticus (NCSE) is characterized by behavioral or cognitive change from baseline for at least 30 minutes with EEG evidence of seizures. Categorized into complex partial status epilepticus (with lateralized seizures), and generalized nonconvulsive status epilepticus (bilateral diffuse synchronous seizures), there is debate regarding the diagnosis and morbidity of NCSE. Because EEG is needed for diagnosis, only a high index of suspicion leads to a request for the study, whereas EEG is often unavailable after hours or on weekends. Furthermore, the cognitive changes during NCSE are often incorrectly ascribed to a postictal state, intoxication, psychogenic or psychotic states, and mental retardation. Regarding categorization, present classifications address EEG features but fail to distinguish among depths of coma. Deeply comatose patients (with coma etiologies that themselves carry poor prognoses) are mixed with lightly obtunded patients with no morbidity, confusing the prognosis. Thus, a classification that subsumes depth of coma, and possibly etiology, is sorely warranted. Regarding treatment, comatose NCSE patients treated with benzodiazepines may worsen, whereas generalized nonconvulsive status epilepticus patients may suffer iatrogenically from aggressive treatment (hypotension and respiratory depression) necessitating balancing the potential neurologic morbidity of NCSE against the possible morbidity of IV antiepileptic drugs. A high index of suspicion is needed to initiate EEG studies. Better stratification of level of consciousness will be needed to distinguish among morbidity due to underlying conditions, treatment, and the effects of status epilepticus, proper.

Status epilepticus: new concepts

Generalized convulsive status epilepticus is a neurological emergency characterized by abnormally prolonged seizures. This review emphasizes recent developments that bear on our understanding of the pathophysiology and management of status epilepticus. Topics include GABAA receptor modulation during prolonged seizures, the role of genetics in susceptibility to status epilepticus, neuron-specific enolas, the Veterans Administration Cooperative Study Group trial comparison of various drug regimens, utility of the electroencephalogram in patient monitoring, emerging drug therapies and patient management in out-of-hospital settings.

Long-term inpatient audiovisual scalp EEG monitoring

Long-term audiovisual scalp EEG monitoring is an essential diagnostic tool for the evaluation of paroxysmal disorders. The definitive classification of both nonepileptic and epileptic events is often possible only with the use of this technique. Assessment of response to treatment and the noninvasive presurgical localization of seizure foci are other important uses. The optimization of both clinical semiology and electrophysiologic data obtained from such studies is the subject of significant research efforts. Outcomes studies and advanced EEG analysis research should ultimately serve to minimize the cost of this valuable technique as well as maximizing its utility.

Progression of electroclinical changes in complex partial status epilepticus: filling in the blanks

Treiman has described five electroclinical stages through which the EEG progresses during generalized convulsive status epilepticus (GCSE). The EEG can show similar patterns in patients with complex partial status epilepticus (CPSE), but there is no agreement as to whether the different patterns seen in the human EEG result from a similar orderly progression through similar stages. We report the case of a patient in CPSE whose EEG passed progressively through two of the earlier stages described by Treiman. This case of EEG progression in a single patient suggests that CPSE can progress through stages analogous to those in GCSE.