Biomedical subjects
Publications and source records attributed to Pierre Jallon.
Status epilepticus (SE) is an emergency situation for the neurologist as for the critical care physician, because it is caused by a focal or by a generalized severe brain suffering. Therefore, SE must be treated as soon as possible. The management, beyond a rapid and accurate diagnosis, must include the identification of the cause of SE, whereas seizures must be rapidly stopped.
PURPOSE: Many studies have shown that cultural and social awareness of, attitudes toward, and knowledge about epilepsy can have an impact on the acceptance of treatment. The aim of this study is to characterize public awareness of attitudes toward and understanding of epilepsy in a Vietnamese community and to compare results with those obtained in other cultures. METHODS: A survey concerning the knowledge, attitudes, and practices of Vietnamese people with respect to epilepsy was carried out in the Nhan Chinh precinct of Hanoi. One thousand people were randomly selected for face-to-face interviews regarding epilepsy. RESULTS: Of the subjects surveyed, 54.6% had heard of epilepsy; 45.5% knew someone with epilepsy; 49.2% had witnessed an epileptic seizure; 56% would not allow their son or daughter to marry someone with epilepsy; 42.1% did not believe that epileptic patients could hold down a normal job; 77.8% believed that epilepsy is an organic disorder of the brain; 23.8% thought that epilepsy is a form of dementia; and 91% thought that epileptic patients require medical care. CONCLUSION: As compared with surveys conducted in other countries, our survey showed that the awareness of epilepsy in this Vietnamese community is limited, and gives rise to alternative attitudes and practices.
PURPOSE: The exact anatomic and neurophysiologic correlates of idiopathic generalized epilepsy (IGE) in humans are still not well understood, although the thalamus has frequently been invoked as the crucial structure in the generation of primary generalized seizures. The few in vivo magnetic resonance (MR)-based studies in IGE patients suggest an altered cortical/subcortical gray matter ratio, but with no evidence of structural alterations of the thalamus. In this study, we sought to determine the volumes of the other subcortical structures. METHODS: The volumes of the caudate nucleus, putamen, pallidum as well as the thalamus were each determined in both hemispheres in 11 patients with various IGE syndromes, normalized for whole-brain volumes and then compared with 15 age-matched controls. RESULTS: No differences were noted in thalamic volumes, confirming previous reports. However, smaller subcortical volumes were noted in the IGE patients (p < 0.009), mainly due to smaller putamen bilaterally (p < or = 0.015). CONCLUSIONS: It is speculated that the presence of discrete frontal dysfunction, as noted in neuropsychological studies in IGE patients, indirectly supports our results because the putamen projects predominantly to the frontal cortex. Larger studies with more homogeneous patient populations are needed to determine the robustness of these findings and whether they are specific for particular IGE syndromes.
Idiopathic generalized epilepsies (IGEs) are a relatively new category of disorders defined by strict clinical and electroencephalogram (EEG) features proposed by the International League Against Epilepsy (ILAE) classification of epileptic syndromes. IGEs are usually easy to diagnose when clinical and EEG data are collected, but epilepsy is not synonymous with epileptic syndrome. So far, IGEs are studied in the large group of epilepsies of undetermined or unknown etiology although the genetic origin is now largely accepted. ILAE-proposed criteria are helpful in the clinical and therapeutic management of IGEs, but many epidemiologic studies still confuse the cryptogenic and idiopathic groups. Some syndromes in childhood, which are completely described by strict electroclinical criteria such as the absence epilepsies, juvenile myoclonic epilepsies, are usually included and analyzed in epidemiologic studies; however, other epileptic syndromes observed in infancy, such as benign familial neonatal seizures and benign myoclonic epilepsy in infancy, are quite rare and are usually excluded from epidemiologic surveys because they are difficult to describe completely in electro-clinical terms. Another strong limitation in the study of epidemiology of IGEs is the lack of EEG data, either because EEG is not available or the routine EEG is normal. This is particularly relevant in the inclusion of patients with only tonic-clonic seizures. IGEs encompass several different syndromes, and a few patients shift from one phenotype to another. The overlapping of some syndromes during infancy and adolescence increased the difficulty to individualize strictly the correct syndrome. Many discrepancies can be observed in the distribution of the different syndromes included in the group of IGEs, because the strict criteria for classifying these syndromes proposed by the ILAE are often not respected. With this understanding, the general frequency of IGEs can be assessed at 15-20% of all epilepsies. The frequency and the distribution of incidence and prevalence of the different syndromes are tentatively reported and discussed. When the term idiopathic is used following the restrictive ILAE criteria, the mortality data concerning patients with idiopathic epilepsies do not show an increased standardized mortality ratio.
OBJECTIVE: In the last decade several studies have been published on incidence, etiology, and prognosis of status epilepticus (SE) with population-based data from the United States and Europe. The aim of this review is to summarize the available information on the epidemiology of SE and to outline the sources of the variability in reported mortality after SE. METHODS: Comparison of mortality studies in SE from the United States and Europe. RESULTS: The incidence of SE is lower in Europe (9.9-15.8/10,000) than in the United States (18.3-41/100,000). The overall mortality after SE is similar in the two U.S. studies: the case fatality is 21% in Rochester, and 22% in Richmond. All European studies excluded SE after anoxic encephalopathy following cardiac arrest. This exclusion may partly explain the lower case fatality (around 10%) found in two of the European studies. The study from Bologna showed the highest case fatality (33%) even after exclusion of anoxic encephalopathy. The mortality in acute symptomatic SE was higher than for other forms of SE across all studies. CONCLUSIONS: Short-term mortality after SE occurs mainly in the acute symptomatic group. Based on published data, it is not clear if differences in early management and medical treatment have any impact on prognosis or whether the differences can be attributed only to differences in distribution of the underlying causes in acute symptomatic SE. Future studies should address this issue.
PURPOSE OF REVIEW: Prospective and retrospective incidence cohort studies have been consistent in identifying an increased mortality in patients with epilepsy, although risk ratios vary considerably. Standardized mortality ratios in these populations range from 1.6 to 5.3, but they tend to be higher in studies in selected populations. RECENT FINDINGS: A few studies have addressed the mortality rate in patients after epilepsy surgery. Mortality seemed to be lower for surgery than for non-surgery patients. The main factors contributing to the late mortality rate in this population are the persistence of seizures after surgery, the long duration of epilepsy before surgery, and the side of the resection. Despite recent improvements in diagnosis and therapeutic management, status epilepticus is still associated with significant mortality, with a case fatality reaching 39%. Early patient management could influence the outcome of status epilepticus. Reports on suicide in epilepsy are based on small samples from different populations, highly selected groups of patients, using different methods of analysis. The rates vary from zero to 25%, and seem to be related more to a psychiatric co-morbidity than the severity of epilepsy. Sudden unexplained death is considered to be the most frequent epilepsy-related death. Clinical and experimental evidence supports the theory that sudden unexplained death is a recent seizure-mediated event with ictal stimulation of the autonomic system. SUMMARY: In some situations, the increased risk of death could be prevented by a better definition of populations at increased risk, better therapeutic management, and adequate neurological follow-up.
PURPOSE: To evaluate the incidence of newly presenting seizures in children in the area of Sousse, Tunisia. METHODS: From June 1, 1998, to May 31, 1999, all children aged 1 month to 15 years with first provoked and unprovoked seizures were included. Children with febrile seizures were excluded. All suspected cases were systematically referred to the Department of Functional Explorations of the Nervous System where a detailed questionnaire was filled out by a neurologist. All the patients underwent an EEG. Only 12 patients had a computed tomography (CT) scan. RESULTS: A total of 175 patients were included. Eighteen (10.3%) patients had acute symptomatic seizures, and 157 patients had unprovoked seizures. The incidence rate of first unprovoked seizures was 102.1/100,000. In this latter group, some epileptic syndromes were individualized on strict electroclinical criteria. CONCLUSIONS: However, nearly 75% of the cases remained cryptogenic, one of the major reasons that no predominant risk factor was identified in this population.
Drug-induced seizures are an uncommon complication of drug therapy. The drug related factors are either the intrinsic epileptogenicity of the specific agent or patient related factors such as convulsive predisposition, underlying neurologic dysfunction, and factors which affect the serum concentration and/or central neurologic system concentrations. Some anti epileptic drugs may aggravate an epileptic syndrome. In 10-15% of patients with epilepsy, better control of seizures can be achieved with combination therapy. These patients are at greater risk of suffering clinically serious interactions. Drug interactions occur at the pharmacokinetic level and at the pharmacodynamic level, involving synergistic or antagonistic effects. Finally many drugs can interfere with the antiepileptic drug metabolism. The inverse effect is also frequent. A better knowledge of the spectrum of drugs that cause seizures or interfere with antiepileptic drugs metabolism is important for evaluation of appropriate treatment options and for guiding the choice of rational therapeutic procedures.
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.
Numerous epidemiological studies concerning the incidence and prevalence of epilepsy and epileptic seizures have been performed in different geographical areas throughout the world. The results of these studies show some disparities in the evaluation of incidence and prevalence rates. Higher incidence rates have been reported in a few studies performed in developing countries. Many prevalence studies seem to corroborate this figure although more recent surveys report similar rates to those observed in the developed world. These controversial results are discussed because there is no scientific reason that the clinical aspects and natural evolution of the disease should be different between developed and developing countries. However, some epidemic or endemic diseases might explain, in part, these figures. On the other hand, the age and sex distribution of the disease seems to be specific to epilepsy and could be related to particular risk factors and some demographic considerations. Apart from obvious methodological biases, the results of these studies lead us to recognize that epilepsy is universal it can occur in any people and is ubiquitous i.e. it is observed in every country but is not an equally distributed disease. Epileptic seizures and epilepsy might be considered as an epidemiological marker of some endemo-epidemic diseases or the results of certain preventive measures.