Biomedical subjects

Benjamin Legros

Publications and source records attributed to Benjamin Legros.

9 recordsLinked to original sources

PubMed2006

Neuromodulation with levetiracetam and vagus nerve stimulation in experimental animal models of epilepsy.

Epilepsy is a neurological disorder consisting of recurrent seizures, resulting from excessive, uncontrolled electrical activity in the brain. Epilepsy treatment is successful in the majority of the cases; however; still one third of the epilepsy patients are refractory to treatment. Besides the ongoing research on the efficacy of antiepileptic treatments in suppressing seizures (anti-seizure effect), we want to seek for therapies that can lead to plastic, neuromodulatory changes in the epileptic network. Neuropharmacological therapy with levetiracetam (LEV) and vagus nerve stimulation (VNS) are two novel treatments for refractory epilepsy. LEV acts rapidly on seizures in both animal models and humans. In addition, preclinical studies suggest that LEV may have antiepileptogenic and neuroprotective effects, with the potential to slow or arrest disease progression. VNS as well can have an immediate effect on seizures in epilepsy models and patients with, in addition, a cumulative effect after prolonged treatment. Studies in man are hampered by the heterogeneity of patient populations and the difficulty to study therapy-related effects in a systematic way. Therefore, investigation was performed utilizing two rodent models mimicking epilepsy in humans. Genetic absence epilepsy rats from Strasbourg (GAERS) have inborn absence epilepsy and Fast rats have a genetically determined sensitivity for electrical amygdala kindling, which is an excellent model of temporal lobe epilepsy. Our findings support the hypothesis that treatment with LEV and VNS can be considered as neuromodulatory: changes are induced in central nervous system function or organization as a result of influencing and initiating neurophysiological signals.

Animals↗

PubMed2006

Standards of care for non-convulsive status epilepticus: Belgian consensus recommendations.

Non-convulsive status epilepticus (NCSE) makes up around one-third of all cases of SE, affecting approximately 1,000 to 4,000 individuals per year in Belgium. Compared with convulsive SE, NCSE has received considerably less attention, is underdiagnosed and undertreated. However, if recognised, NCSE can however be treated successfully. A workshop was convened by neurologists from major Belgian centres to review the latest information on NCSE and to make recommendations on diagnosis and treatment. These recommendations are not only intended for neurologists, but also for primary care physicians and physicians in intensive care units. NCSE should be suspected whenever cases of fluctuating consciousness or abrupt cognitive or behavioural changes are noted. Confirmation of diagnosis by EEG should be obtained wherever possible. In view of the often subtle clinical signs, EEG is also vital for monitoring treatment outcome. Non-comatose patients should generally be treated in a neurology ward since referral to an ICU is unnecessary. First-line treatment should be an intravenous benzodiazepine. For many patients who fail to respond to benzodiazepines, intravenous valproate will successfully abrogate seizure activity. Intravenous phenytoin can be used in patients with focal NCSE in whom valproate is contraindicated or ineffective. Time and care should be spent in identifying an appropriate and effective antiepileptic drug regimen without recourse to anaesthesia. For comatose patients, treatment intensity should be graded according to epilepsy history, general medical state and prognosis. In some patients, intensive remedial measures may allow rapid resolution of NSCE, whereas in more vulnerable patients, such treatment may be counterproductive.

Algorithms↗

PubMed2005

Rapid kindling in preclinical anti-epileptic drug development: the effect of levetiracetam.

PURPOSE: This study assesses the use of the serial day Rapid Kindling with Recurrent Hippocampal Seizures (RKRHS) model in drug testing by investigating the anti-epileptic effect of levetiracetam (LEV), a novel anti-epileptic drug (AED) with a unique preclinical profile. METHODS: Male Wistar rats (n=16) were implanted with a stimulation/recording electrode unit in the right hippocampus and epidural recording electrodes. One week later, all rats received 12 stimulations each day for several consecutive days according to the serial day RKRHS protocol, until they were fully kindled. Fully kindled rats were then randomly assigned to an active (n=8) and a control (n=6) group and injected once (intraperitoneal, i.p.) with levetiracetam (54 mg/kg) or saline (0.9% NaCl, 2 ml/kg), respectively. One hour later, the rats received additional kindling stimulations, during which the effect of LEV was assessed. RESULTS: One hour following injection of LEV, mean seizure stage dropped to 1.67+/-1.03 compared to 5+/-0 in controls (p<0.05). Mean ADD was also significantly shorter in the active group than in controls; 21.16+/-5.03 s versus 57.24+/-8.16s, respectively (p<0.05). A gradual, time-dependent decline was noted in the anti-epileptic effect of LEV but this effect stayed statistically significant at least up to 2.5 h (p<0.05). CONCLUSION: LEV was demonstrated to have anti-epileptic properties in RKRHS that compared to those in traditional kindling and contrast with results from classical screening tests. RKRHS may represent a valuable and sensitive screening tool early in the drug screening process.

Animals↗

PubMed2005

Usefulness of prolonged video-EEG monitoring and provocative procedure with saline injection for the diagnosis of non epileptic seizures of psychogenic origin.

OBJECTIVES: To assess the usefulness of long term video-EEG monitoring (VEEGM) and intravenous injection of saline solution (IVISS) for the diagnosis of non epileptic seizures of psychogenic origin (PNES). BACKGROUND: PNES are common among patients referred to an epilepsy center. Long term VEEGM remains the gold standard method for assessing the correct diagnosis. However, spontaneous PNES do not always occur during VEEGM, and a provocative test is often required. Although IVISS is the most commonly performed method, its usefulness is still debated. METHODS: We performed a long term VEEGM and an IVISS test the last day of the monitoring to each patient admitted to the Epilepsy Monitoring Unit of Erasme Hospital, Brussels, between October 2001 and February 2005 for suspicion of PNES. Patient charts were retrospectively reviewed. RESULTS: Of a total of 138 patients admitted to our center, 28 (20.3%) were referred for suspicion of PNES. There were 7 men and 21 women with a mean age of 35 years. Twenty-one patients (75%) had PNES during the VEEGM. Ten patients (36 %) had spontaneous PNES and positive IVISS. Nine patients (32 %) had no spontaneous PNES but a positive IVISS. Two patients (7 %) had spontaneous PNES and a negative IVISS. Among patients with PNES, 8 had also epileptic findings. CONCLUSION: IVISS is a useful diagnostic tool since it was the only way to confirm the diagnosis of PNES in 32% of our patients. We suggest that investigation for the diagnosis of PNES should always include both a prolonged VEEGM and an IVISS test.

Adult↗

PubMed2005

Standards of care for adults with convulsive status epilepticus: Belgian consensus recommendations.

Status epilepticus (SE) is a significant health problem, affecting approximately 1,000 to 4,000 individuals per year in Belgium. A workshop was convened by a panel of neurologists from major Belgian centers to review the latest information relating to the definition, diagnosis and treatment of convulsive SE. The panelists sought to make recommendations for practising neurologists, but also primary care physicians and physicians in intensive care units when initiating emergency measures for patients with convulsive SE. As there is an association between prolonged seizures and a poor outcome, the importance of early (within the first 5 minutes of seizure onset) and aggressive treatment is to be stressed. In addition to general systemic support (airway, circulation), intravenous administration of the benzodiazepines lorazepam or diazepam is recommended as first-line therapy. Intramuscular midazolam may also be used. If SE persists, second-line drugs include phenytoin or valproate, and third-line drugs the barbiturate phenobarbital, the benzodiazepine midazolam, or the anaesthetics thiopental or propofol, or eventually ketamine. If the patient does not recover after therapy, monitoring of seizures should involve an electroencephalogram to avoid overlooking persistence of clinically silent SE. As a general rule, the intensity of the treatment should reflect the risk to the patient from SE, and drugs likely to depress respiration and blood pressure should initially be avoided. If initial treatment with a benzodiazepine fails to control seizures, the patient must be referred to the emergency unit and a neurologist should be contacted immediately.

Adult↗

PubMed2004

Progressive myoclonic epilepsy.

Progressive myoclonic epilepsies (PMEs) are a group of rare disorders characterized by the occurrence of seizures, myoclonus, and progressive neurological dysfunction. This article discusses epidemiology, genetics, pathology, clinical manifestations, EEG characteristics, methods of diagnosis and treatment of the most common causes of PME, including Unverricht-Lundborg Disease (Baltic Myoclonus), MERRF, neuronal ceroid lipofuscinosis, dentatorubropallidoluysan atrophy, Gaucher disease, Lafora disease, and sialidosis. The aim of this paper is to provide clinicians with useful clinical information in order to facilitate the diagnosis and treatment of these rare diseases.

Humans↗

PubMed2004

Belgian consensus on recommendations for standards of care for women with epilepsy before, during and after pregnancy.

Women with epilepsy (WWE) have an increased risk of complications during pregnancy, which however can be minimized by optimal, interdisciplinary patient management. The aim of any therapy is to achieve an optimal balance between avoidance of seizures, which may be harmful to both mother and foetus, and minimization of foetal and neonatal exposure to deleterious influences of antiepileptic drugs. Suitable measures include early and regular counselling of the young WWE about contraception and planning of pregnancy, optimisation of drug treatment (choice of the right drug and dosage also in view of altered pharmacokinetics, avoidance of polytherapy, therapeutic drug monitoring etc.), in-time folate substitution, and close follow-up of the patient during and after pregnancy. Until now, many issues such as underlying factors of malformations have not been clearly elucidated. Nonetheless, chances for an unproblematic pregnancy of WWE are high.

Adult↗

PubMed2003

Effects of antiepileptic drugs on sleep architecture: a pilot study.

OBJECTIVES: The effects of antiepileptic drugs (AEDs) on sleep architecture are not well understood, especially in patients with localization-related epilepsy, in whom seizures themselves can disrupt sleep. To clarify the effects of AEDs on sleep architecture, we performed a prospective study, looking at sleep architecture in patients with epilepsy admitted for video-EEG monitoring. METHODS: Adult patients with localization-related epilepsy treated with a single AED and admitted between 10/1997 and 04/2001 were included. Control patients on no AEDs were also included. Both groups were withdrawn from other AEDs. Overnight polysomnography was recorded and was scored according to the standard method. Adult patients with localization-related epilepsy on no medication were also recorded and served as controls. Patients with no seizure during the recording and no seizure in the 24 h preceding the recording were analyzed in this paper. Patients with a seizure in the 24 h preceding the recording and patients with a seizure during the recording were analyzed separately. RESULTS: A total of 72 nights were recorded in 39 patients, and patients taking each AED were compared to controls. We did not find any statistically significant effect of carbamazepine (CBZ). Phenytoin (PHT) disrupted sleep by increasing stage 1 sleep (PHT: 13.2+/-7.3%; control: 7.7+/-4.8%; P=0.008), and decreasing slow wave sleep (SWS) (PHT: 7.9+/-4.2%; control: 11.3+/-4.4%; P=0.03) and REM sleep (PHT: 13.9+/-6.2; control: 18.8+/-5.1; P=0.01). Valproic acid (VPA) disrupted sleep by increasing stage 1 sleep (VPA: 16.8+/-9.8%; control: 7.7+/-4.8%; P=0.007). Gabapentin (GBP) improved sleep by increasing SWS (GBP: 19.4+/-4.2%; control: 11.3+/-4.4%; P=0.0009). PHT and VPA disrupt sleep in the absence of seizures, while CBZ and lamotrigine have no significant effects. GBP improves sleep by increasing SWS. CONCLUSIONS: AEDs have differing effects on sleep structure, which can be beneficial or detrimental. Consideration of these potential effects is important in maintaining optimal sleep in patients with epilepsy.

Adult↗

PubMed2003

Sleep structure in patients with psychogenic nonepileptic seizures.

Psychogenic nonepileptic seizures (PNES) are a significant public health problem, occurring in perhaps 25% of patients admitted to epilepsy monitoring units. Additional distinguishing characteristics for these patients would be helpful from both a clinical and a scientific standpoint. This study examines sleep structure by polysomnography in patients with PNES compared with patients with epileptic seizures (ES). ES and PNES were verified by video-EEG monitoring. All patients with PNES were evaluated by a psychiatrist. Eight female patients with PNES were compared with 10 female ES patients in the same age group. Percentage REM sleep was significantly greater for women with PNES (23+/-1%) than for those with ES (18+/-1%). There were no differences in other sleep stages, total sleep time, or sleep efficiency. REM latency was less in PNES patients although not significantly. The study suggests that patients with PNES have a sleep architecture similar to that found in major depression, known to be associated with increased REM sleep.

Adolescent↗