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.     

Star fruit (Averrhoa carambola) toxic encephalopathy

Ingestion of star fruit (Averrhoa carambola) can induce severe intoxication in subjects with chronic renal failure. Oxalate plays a key role in the neurotoxicity of star fruit. We report the cases of two patients with unknown chronic renal insufficiency who developed severe encephalopathy after ingestion of star fruit. The two patients developed intractable hiccups, vomiting, impaired consciousness and status epilepticus. Diffusion-weighted MR imaging showed cortical and thalamic hyperintense lesions related to epileptic status. They improved after being submitted to continuous hemofiltration which constitutes the most effective treatment during the acute phase.     

Diagnostics différentiels des états de mal épileptiques

The diagnosis of status epilepticus can be retained, wrongly, in several circumstances. Nonepileptic pseudoseizures from a psychiatric origin and some movement disorders can mimic convulsive status epilepticus. Encephalopathy of various causes (post-anoxic, metabolic, toxic, Creutzfeldt-Jakob disease) can be wrongly taken for non-convulsive status epilepticus, mainly due to inadequate interpretation of the electroencephalogram (EEG). In these encephalopathies, the existence of (non-epileptic) myoclonus and the abolition of the EEG abnormalities with the use of a benzodiazepine (without correction of the clinical symptoms) are additional confounding factors, leading to false diagnosis. Nevertheless, in general, the diagnosis of status epilepticus can be confirmed or rejected base on a combined analysis of the clinical data and the EEG.     

Utilisation du lorazépam injectable dans le traitement de l’état de mal épileptique : étude comparative au sein d’hôpitaux pédiatriques francophones

Background

Injectable lorazepam (IL) is marketed in many countries but in France is only available within the framework of a compassionate use program for refractory status epilepticus. This study aims to evaluate the differences of pediatric use and status of IL in the hospitals of the Mother-Child French-speaking Network (Réseau mère-enfant de la francophonie, i.e., RMEF).

Methods

Inclusion criteria are: firstly, RMEF member; secondly, one site per town; thirdly, all the Assistance publique-Hôpitaux de Paris hospitals. After a phone-recruitment in each selected hospital, a survey was sent by e-mail. The data collected concerned the number of beds in the hospital, the official status of IL, its place in the therapeutic strategy, inhospital consumption in 2008 (in milligram) and the therapeutic alternatives.

Results

Among the 18 hospitals selected, 17 were contacted and 12 (70%) replied. IL is not marketed in Tunisia and Lebanon. In Switzerland, Canada and Belgium, IL is marketed and used in all the polled hospitals (6.2 to 48.0 mg per bed). In France, only the Robert Debré Hospital uses it (3.2 mg per bed). In the countries where it is marketed, IL was firstly prescribed for the studied indication. In the other countries, injectable diazepam was the first line treatment (six out of eight hospitals).

Discussion/conclusion

France is the only country where IL is available though not marketed. The pharmacokinetic data favor use of IL instead of its principal therapeutic alternative (injectable diazepam) but no currently available evidence concludes that IL is superior to diazepam in the management of pediatric status epilepticus. The official indication of IL in France (last intention) is in contradiction with its use in the countries where it is marketed and with the data of the literature in favor of the first intention. This works presents the first evaluation on the use of IL in pediatric status epilepticus in the RMEF hospitals. It highlights the discrepancies in the management of status epilepticus in comparable pediatric hospitals.     

Électroencéphalographie dans les états de mal épileptiques : glossaire, protocole et interprétation

Electroencephalography is a useful tool in the diagnosis and management of status epilepticus (SE) and it can also give prognostic information. It can help to confirm that an episode of SE has ended. It can identify the patients who have unsuspected subclinical seizures. There is a wide range of presentations of SE. Nearly all types of seizures have the potential of occurring in a repeated or continuous form. The polymorphic EEG patterns in SE reflect this wide variety. But controversial patterns also exist in the form of periodic epileptiform discharges. While some authors considered these patterns to be interictal or postictal, others postulate that these patterns are ictal. In these cases, clinical features are very important in order to conclude. Generalized convulsive SE is a medical emergency and the EEG is not necessary to make a diagnosis. Convulsive generalized SE requires immediate treatment and in this case, EEG is used in guiding treatment especially in refractory SE that may evolve into subtle SE. In non-convulsive SE, diagnosis is not obvious on the basis of clinical signs and symptoms alone and the diagnosis must be confirmed by urgent EEG. EEG can also be used to distinguish SE from psychogenic seizures, movement disorders and in patients who have causes of persistent loss of consciousness (metabolic encephalopathy, postanoxic encephalopathy). This article proposes a protocol for the use of the EEG in SE, guidelines and simple vocabulary for a good interpretation and comprehension of the EEG.     

Traitement pharmacologique de l’état de mal réfractaire

Status epilepticus (SE) refractory to benzodiazepines and other antiepileptic agents is managed with intravenous anesthetic compounds, such as thiopental, propofol or midazolam. These drugs display quite different pharmacodynamic and pharmacokinetic properties, but have not been prospectively compared to date. Their use is clearly advocated for the treatment of generalized convulsive SE, whereas partial-complex, or absence SE are generally managed less aggressively, in consideration of their better prognosis. The most important aspect seems to be related to the correct use of these anesthetics in the right context, rather than the choice of one specific compound. An electroencephalographic burst-suppression should be targeted for about 24 hour, before progressive weaning of the dosage under EEG monitoring. If this approach proves unsuccessful, the use of other drugs, including inhalational anesthetics, has been described.     

Épilepsies généralisées idiopathiques chez le sujet âgé : le point de vue du gériatre

Introduction

Long-term follow-up studies indicate a low remission rate in idiopathic generalised epilepsies (IGE) (Martinez-Juarez et al., 2006), suggesting they may persist to an advanced age. However there are few estimates of IGE frequency in the elderly.

Methods

EEGs of 700 patients aged over 70 years, recorded between January 2006 and March 2007, were reviewed for anomalies consistent with IGE. We then examined the clinical history of patients with these anomalies.

Results

A persistent IGE was identified in four female patients (mean age: 79 years); in two cases it was a juvenile myoclonic epilepsy (JME) and in two an epilepsy with grand mal seizures. Seizures in three patients had begun in childhood or adolescence and in one at 40 years. Before hospitalization, few or no seizures were reported and IGE had not been diagnosed. IGE was revealed in each patient by a relatively severe event: an absence status (AS), subcontinuous myoclonic seizures or repeated convulsive generalised seizures (CGS). These events were not situation-related but in one patient the relapse of simple convulsive seizures, may have been related to the withdrawal of anti-epileptic drugs (AED) several months previously. EEG records showed generalised spikes or polyspikes and waves organised in a status epilepticus or in interictal rhythmic discharges. In one case they were evident only from a 24 hours recording. Clonazepam injection was used to suppress the AS episode and the subintrant myoclonia. After the AS, interictal generalised epileptic discharges persisted. Two of the four patients had familial history of epilepsy or febrile seizures but in no case was an epileptogenic lesion evident in brain CT scan or MRI. Clinical exams and biologic parameters were normal. All of the patients had worked and were married with children. Appropriate therapies were followed after the diagnosis of IGE. One patient with JME had been treated by Valproate which was discontinued by the general practitioner because of lethargy and replaced by Carbamazepine; seizures were aggravated under both Carbamazepine and then Lamotrigine and until the patient became seizure-free on Levetiracetam. The antiepiletic treatment was also modified in a second patient, while the two others responded well to Valproate.

Conclusions

IGE can exacerbate in the elderly, as different types of seizures including AS, subintrant myoclonia or repeated CGS. Our data suggest persistent IGE are quite frequent in an aged population and may be underestimated due to difficulties in diagnosis. Correctly diagnosed, adjustment of AED may offer substantial clinical improvements in IGE of the elderly.     

États de mal épileptiques : épidémiologie, définitions et classifications

The annual incidence of status epilepticus based on the definitions of the International League Against Epilepsy (1993) ranges from 10.3 to 41 per 100,000 inhabitant. Half of the cases of status epilepticus concern epileptic patients. In all studies, incidence is higher in epileptic patients, young children and the elderly. It is estimated that 13% of patients with status epilepticus will experience recurrence during the two first years. The three leading etiologies are low-dose antiepileptic drugs, non-acute brain lesions and acute stroke. Seizures are generalized in 9 to 33% of patients and focal in 25 to 75%. Secondary generalized seizures can be observed in 19 to 66% of patients. Mortality ranges from 7.6 to 39% and varies as a function of inclusion of postanoxic encephalopathies and difference in initial care. The definition retained and the classification adopted for status epilepticus also affect mortality estimates. Status epilepticus is defined as the existence of a prolonged seizure or a series of seizures during which the patient does not recover, or incompletely recovers, consciousness. The duration parameter used to distinguish status epilepticus from a seizure remains controversial. At the present time, there is general agreement in the literature distinguishing two definitions based on different durations according to the clinical type of status epilepticus and its potential severity: (i) a status epilepticus is defined by a seizure lasting more than 30 minutes or recurrent seizures without recovery of consciousness over a period of 30 minutes; (ii) considering its severity, tonic-clonic status epilepticus has a specific definition leading to earlier therapeutic management. This operational definition is continuous, generalized, convulsive seizure lasting more than five minutes or two or more seizures during which the patient does not return to baseline consciousness. Several types of background can be used to establish a classification for status epilepticus: clinical manifestations, prognostic and therapeutic course, epidemiological data, pathophysiological mechanisms… At the present time, the classifications most commonly used in France for status epilepticus are derived from the syndromic epileptic classification, the seizure classification or the classification proposed by the French consensus workshop on status epilepticus. For routine clinical practice, an operational classification can be used to adopt therapeutic strategies adapted to probable prognosis: short-term life-threatening, mid-term life-threatening, not life-threatening.     

Prise en charge de l’état de mal tonicoclonique généralisé : stratégies thérapeutiques

Increasing duration of generalized tonic-clonic status epilepticus increases the risk of neuronal damage and systemic complications. It is also a recognized contributing factor to drug resistance. The most indispensable quality an anticonvulsive medication is expected to have in this situation is therefore a rapid therapeutic effect, achieved without severe depressive, neurological, cardiovascular or respiratory side effects. The anticonvulsive strategy proposed here takes into account these prerequisites, as well as previously published research findings which remain limited on a number of aspects. The duration of the convulsions before medication must be taken into account when deciding on the initial treatment. If this is less than 30 min, a single drug regimen with benzodiazepine would be appropriate and sufficient initially. If lorazepam, which is unavailable in France, cannot be used, the pharmacokinetically similar clonazepam should be preferred. Beyond 30 min, a combination of benzodiazepine and an anticonvulsive with long-lasting effects —phenobarbital or fosphenytoin— is indicated. The choice between these two latter drugs depends on their respective contraindications and the circumstances surrounding the occurrence of the status epilepticus. The persistence of seizures beyond 20 min after beginning the phenobarbital infusion or 30 min after starting fosphenytoin signals a failure of the initial treatment and requires the immediate introduction of a second line of therapy. This may be an anticonvulsive with long-lasting effects providing the convulsions have been present for less than an hour, there is no suspicion of an acute cerebral lesion and there is no associated systemic factor of cerebral aggression. If not, the employment of anesthetic medication is immediately required.     

Alcohol and epilepsy: a case report between alcohol withdrawal seizures and neuroborreliosis

Objectives

This work consists in a study of the links between alcohol, a psychoactive substance and different related epileptic manifestations in order to clarify predominant factors both on conceptual, clinical and therapeutic levels.

Background

If alcohol is a frequent risk factor for seizures, its scientific evidence is less clear and ad hoc literature is rich in controversies and not firmly supported by systematic surveys. Alcohol has variable roles in the physiopathological determinism of seizures, the nosographical status of which needs to be clarified: alcohol withdrawal seizures, alcoholic epilepsy, and sometimes symptomatic epilepsy caused by coincidental disorders.

Methods

A synthesis of relevant literature describing the links between alcohol and epilepsy is illustrated by a clinical case: a patient admitted in our psychiatric ward for chronic alcoholism had had two seizures questioning their nosographical status. An infectious process with protean neurological manifestations, neuroborreliosis, was diagnosed.

Discussion

Three distinct clinical pictures illustrate the links between alcohol and epilepsy: the first, convulsive inebriation corresponds to a seizure during severe acute alcohol intoxication. The second deals with alcohol withdrawal seizures following a partial or complete sudden withdrawal of alcohol; these are the clinical features the most documented in the literature representing, with delirium tremens, the main complication of alcohol withdrawal. The third clinical picture, alcoholic epilepsy, is characterized by repetitive seizures in patients presenting alcohol abuse without former history of epilepsy or other potentially epileptic disorder, and without relationship to alcohol withdrawal or acute alcohol intoxication. Acute and chronic effects of alcohol on central nervous system have been depicted, while a unified classification of alcohol related seizures has been recently established by Bartolomei. This classification based on the Ballenger hypothesis of kindling (1978) could explain withdrawal and hazardous seizures as clinical expressions of the same epileptogenic process over different stages. Although theoretically criticized, such a model offers a conceptual interest while able to unify the varied understanding of convulsive crises related to alcohol, and a practical one, whilst being a basis for a therapeutic approach. Our clinical case illustrates the delay in the diagnosis established after two iterative generalized seizures, 72 hours after the beginning of a programmed weaning of a patient presenting alcohol dependency. If the withdrawal seizure hypothesis was underlined, some data led to symptomatic epilepsy. Firstly atypia, the well-supervised preventive treatment of convulsion did not avoid seizures. Secondly, the EEG showed focal anomalies strongly linked in the literature with a cerebral disorder, which was confirmed by MRI; thirdly, cognitive alterations, which are not usual in alcohol dependency, were observed clinically and confirmed by neuropsychological tests. Finally a neuroborreliosis was diagnosed, while the main neuropsychiatric complications of Lyme disease were described. In accordance with the recommendations made by some authors, it appeared legitimate to consider neuroborreliosis as a potential differential diagnosis of every atypical psychiatric disorder, the interest of such an identification laying in the existence of a specific treatment.     

Autobiographic memory: Phenomenological aspects, personal semantic knowledge, generic events and characters (one case of pure retrograde memory recovery)

Tulving et al. [Brain Cogn 8 (1988) 3-20] proposed an operational distinction concerning memory between a semantic component consisting of general information about the individual's past and an episodic component, containing memories of specific events that can be situated in space and time. After a mild head trauma and in the context of professional troubles, patient FF displayed a pure retrograde amnesia concerning both his biographical identity and semantic memories. The patient could no longer access his memories. However, these did not seem completely lost since his answers to tests concerning historical events were better than random, his answers to a television quiz were automatic, he showed temporal transfer phenomena (ecmnesia) and since he retrieved the entirety of his memories within nine months. The patient FF illustrates the loss of retrograde autobiographic memory and the recovery of episodic memories, which requires three elements: a sense of subjective time, an autonoetic awareness (the ability to be aware of subjective time) and a "self" that can travel in subjective time.     

Building and validation of a test evaluating verbal recognition memory: The Forty test (f40)

Introduction

Neuropsychologic evaluation is a primordial diagnostic tool. Numerous tests explore episodic memory but few tests exist to assess incidental verbal episodic memory or verbal recognition memory. This memory is however impaired early in certain neurodegenerative diseases such as Alzheimer's disease. Our objective was to create a test sensitive and specific to this cognitive dysfunction.

Method

Our test was performed by 33 healthy volunteers and 51 patients (19 with idiopathic Parkinson's disease, 16 with Alzheimer's disease at the prodromal stage and 16 with Alzheimer's disease).

Results and discussion

Independently of age, education level and global cognitive impairment, the young and old healthy volunteers and the patients with idiopathic Parkinson's disease displayed results significantly better than the group of Alzheimer's disease at the prodromal stage and Alzheimer's disease patients. Our test appears to be sensitive to dysfunction of verbal recognition memory. A score of 30/40 or less on the Forty test discriminates 91% of subjects with a cortical pattern of memory. This test could be recommended for clinical neuropsychological practice.