The epidemiology of epilepsy in Europe - a systematic review

Adjunctive therapy of uncontrolled partial seizures with levetiracetam in Australian patients

OBJECTIVE

The goal of the work described here was to explore the efficacy, safety, and tolerability of adjunctive therapy with levetiracetam and associated changes in health-related quality of life in Australian patients with uncontrolled partial seizures.

METHODS

A phase IV open-label 16-week clinical trial was undertaken. Patients received adjunctive levetiracetam, adjusted according to clinical response to a final daily dose of 1000-3000 mg. Seizure frequency and adverse events were recorded. A quality-of-life questionnaire (QOLIE-10-P) was administered at the start and end of therapy.

RESULTS

The intention-to-treat population (N=152) experienced a median reduction in total seizure frequency of 57.7%. The 50% responder rate was 56.6%, and 12.5% of patients were free of seizures throughout the trial. Adverse events were mostly mild or moderate, leading to discontinuation in 9.9%. The most common adverse events were somnolence, fatigue, headache, and dizziness. Behavioral adverse events occurred in approximately one-quarter of patients, including two-thirds of those who withdrew because of adverse events. There was an improvement in the QOLIE-10-P score.

CONCLUSION

Levetiracetam is effective and well tolerated when added to existing therapy in patients with uncontrolled partial seizures.

Intraoperative ultrasound to define focal cortical dysplasia in epilepsy surgery

Focal cortical dyplasia (FCD) is a frequent cause of medication-resistant focal epilepsy. Patients with FCD may benefit from epilepsy surgery. However, it is difficult to intraoperatively define lesion boundaries. In this case report we present a novel tool to identify FCD intraoperatively. A patient with frontal lobe epilepsy underwent resection of a left frontomesial FCD. Image guidance was achieved by intraoperative ultrasound, which depicted the lesion with a higher resolution than preoperative MRI. Postoperatively the patient remained seizure free. Intraoperative ultrasound may be helpful in identifying and targeting subtle epileptogenic lesions, which are difficult to visualize.

Expression changes in mouse brains following nicotine-induced seizures: the modulation of transcription factor networks

Nicotine, acting through the neuronal nicotinic acetylcholine receptors (nAChRs), can induce seizures in mice. We aimed to study brain transcriptional response to seizure and to identify genes whose expression is altered after nicotine-induced seizures. Whole brains of untreated mice were compared with brains 1 h after seizure activity, using Affymetrix U74Av2 microarrays. Experimental groups included wild-type mice and both nicotine-induced seizure-sensitive and -resistant nAChR mutant mice. Each genotype group received different nicotine doses to generate seizures. This approach allowed the identification of significantly changed genes whose expression was dependent on seizure activity, nicotine administration, or both but not on the type of nAChR subunit mutation or the amount of nicotine injected. Significant expression changes were detected in 62 genes ( P < 0.05, false discovery rate correction). Among them, gene ontology functional annotation analysis determined that the most significantly overrepresented categories were of genes encoding MAP kinase phosphatases, regulators of transcription and nucleosome assembly proteins. In silico bioinformatic analysis of the promoter regions of the 62 changed genes detected significant enrichments of 16 transcription regulatory elements (TREs), creating a network of transcriptional regulatory responses to seizures. The TREs for activating transcription factor and serum response factor were most significantly enriched, supporting their association with seizure activity. Our data suggest that nicotine-induced seizure in mice is a useful model to study seizure activity and its global brain transcriptional response. The differentially expressed genes detected here can help us to understand the molecular mechanisms underlying seizures in animal models and may also serve as candidate genes to study epilepsy in humans.

Elevated rates of testosterone-related disorders in women with autism spectrum conditions

The androgen theory of autism proposes that autism spectrum conditions (ASC) are in part due to elevated fetal testosterone (FT) levels, which are positively correlated with a number of autistic traits and inversely correlated with social development and empathy. A medical questionnaire was completed by n=54 women with ASC, n=74 mothers of children with ASC, and n=183 mothers of typically developing children to test whether women with ASC have an increased rate of testosterone-related medical conditions, and to see whether mothers of children with ASC show similar abnormalities, as part of the 'broader autism phenotype'. Compared to controls, significantly more women with ASC reported (a) hirsutism, (b) bisexuality or asexuality, (c) irregular menstrual cycle, (d) dysmenorrhea, (e) polycystic ovary syndrome, (f) severe acne, (g) epilepsy, (h) tomboyism, and (i) family history of ovarian, uterine, and prostate cancers, tumors, or growths. Compared to controls, significantly more mothers of ASC children reported (a) severe acne, (b) breast and uterine cancers, tumors, or growths, and (c) family history of ovarian and uterine cancers, tumors, or growths. These results suggest current hormone abnormalities in women with ASC and their mothers. Direct investigations of serum testosterone levels and genetic susceptibility to high testosterone production or sensitivity in women with ASC would illuminate the origin of these conditions. The relationship between FT and current testosterone levels also needs to be clarified. The present results may be relevant to understanding the increased male risk to developing autism.

A study of idiopathic generalised epilepsy in an Irish population

Idiopathic generalised epilepsy (IGE) is subdivided into syndromes based on clinical and EEG features.

PURPOSE

The aim of this study was to characterise all cases of IGE with supportive EEG abnormalities in terms of gender differences, seizure types reported, IGE syndromes, family history of epilepsy and EEG findings. We also calculated the limited duration prevalence of IGE in our cohort.

METHODS

Data on abnormal EEGs were collected retrospectively from two EEG databases at two tertiary referral centres for neurology. Clinical information was obtained from EEG request forms, standardised EEG questionnaires and medical notes of patients.

RESULTS

two hundred twenty-three patients met our inclusion criteria, 89 (39.9%) male and 134 (60.1%) females. Tonic clonic seizures were the most common seizure type reported, 162 (72.65%) having a generalised tonic clonic seizure (GTCS) at some time. IGE with GTCS only (EGTCSA) was the most common syndrome in our cohort being present in 94 patients (34 male, 60 female), with 42 (15 male, 27 female) patients diagnosed with Juvenile myoclonic epilepsy (JME), 23 (9 male, 14 female) with Juvenile absence epilepsy (JAE) and 20 (9 male, 11 female) with childhood absence epilepsy (CAE). EEG studies in all patients showed generalised epileptiform activity.

CONCLUSIONS

More women than men were diagnosed with generalised epilepsy. Tonic clonic seizures were the most common seizure type reported. EGTCSA was the most frequent syndrome seen. Gender differences were evident for JAE and JME as previously reported and for EGTCSA, which was not reported to date, and reached statistical significance for EGTCA and JME.

Die Kosten von "Gehirnerkrankungen" in Österreich im Jahr 2004

OBJECTIVES

The costs of twelve selected neurological, neuro-surgical and psychiatric disorders in Austria in the year 2004 will be presented. The present paper is part of the "Cost of Disorders of the Brain in Europe" study.

METHODS

The data for the present calculations are based on systematic reviews of epidemiological and health-economic studies. For all European countries identical methods were applied. All economic data were transformed to Euros for Austria in the year 2004 ("Purchasing Power Parity adjusted").

RESULTS

The highest costs per case per disorder were caused by brain tumors (49,800 Euro) and multiple sclerosis (30,500 Euro). One-year-prevalence estimates (Austrian population 8.1 million) were highest for anxiety disorders (848,000 cases), followed by migraine (537,000 cases) and affective disorders (479,000 cases). The total costs (i.e. for all cases of a specific disorder in Austria) were highest for affective disorders and addiction (alcohol and illegal drugs). The total cost of all included disorders (addiction, affective disorders, anxiety disorders, brain tumours, dementia, epilepsy, migraine, multiple sclerosis, Parkinson's disease, psychotic disorders, stroke and brain trauma) was estimated at 8.8 billion Euros for Austria in the year 2004. Direct health care cost amounted to Euros 3.2 billion (37% of total cost), direct non-medical cost totalled Euros 1.5 billion (17%), and indirect cost Euros 4.1 billion (47%).

DISCUSSION

Even when considering that such estimates based on international studies have methodological limitations, the total cost of the twelve included disorders is considerable. The total cost of these twelve disorders constitutes 4% of the gross national product of Austria. Taken together, these disorders cost each Austrian citizen Euros 1 090 per year.

Cellular Mechanisms Underlying Antiepileptic Effects of Low- and High-Frequency Electrical Stimulation in Acute Epilepsy in Neocortical Brain Slices In Vitro

Approximately 30% of epilepsy patients suffer from drug-resistant epilepsy. Direct electrical stimulation of the epileptogenic zone is a potential new treatment modality for this devastating disease. In this study, we investigated the effect of two electrical stimulation paradigms, sustained low-frequency stimulation and short trains of high-frequency stimulation, on epileptiform discharges in neocortical brain slices treated with either bicuculline or magnesium-free extracellular solution. Sustained low-frequency stimulation (5–30 min of 0.1- to 5-Hz stimulation) prevented both interictal-like discharges and seizure-like events in an intensity-, frequency-, and distance-dependent manner. Short trains of high-frequency stimulation (1–5 s of 25- to 200-Hz stimulation) prematurely terminated seizure-like events in a frequency-, intensity-, and duration-dependent manner. Roughly one half the seizures terminated within the 100-Hz stimulation train ( P < 0.01 compared with control), whereas the remaining seizures were significantly shortened by 53 ± 21% ( P < 0.01). Regarding the cellular mechanisms underlying the antiepileptic effects of electrical stimulation, both low- and high-frequency stimulation markedly depressed excitatory postsynaptic potentials (EPSPs). The EPSP amplitude decreased by 75 ± 3% after 10-min, 1-Hz stimulation and by 86 ± 6% after 1-s, 100-Hz stimulation. Moreover, partial pharmacological blockade of ionotropic glutamate receptors was sufficient to suppress epileptiform discharges and enhance the antiepileptic effects of stimulation. In conclusion, this study showed that both low- and high-frequency electrical stimulation possessed antiepileptic effects in the neocortex in vitro, established the parameters determining the antiepileptic efficacy of both stimulation paradigms, and suggested that the antiepileptic effects of stimulation were mediated mostly by short-term synaptic depression of excitatory neurotransmission.

Medical history, cigarette smoking and risk of acoustic neuroma: an international case-control study

Acoustic neuroma (vestibular schwannoma) is a benign tumor of the vestibulocochlear nerve. Its recorded incidence is increasing but risk factors for this tumor have scarcely been investigated. We conducted a population-based case-control study of risk factors for acoustic neuroma in the UK and Nordic countries, including 563 cases and 2,703 controls. Tumor risk was analyzed in relation to medical history and cigarette smoking. Risk of acoustic neuroma was significantly raised in parous compared with nulliparous women (OR = 1.7, 95% CI: 1.1-2.6), but was not related to age at first birth or number of children. Risk was not associated with a history of allergic disease, past head injury, past diagnosis of a neoplasm or birth characteristics, but was significantly raised for past diagnosis of epilepsy (OR = 2.5, 95% CI: 1.3-4.9). Tumor risk was significantly reduced in subjects who had ever regularly smoked cigarettes (OR = 0.7, 95% CI: 0.6-0.9), but the reduction applied only to current smokers (OR = 0.5, 95% CI: 0.4-0.6), not ex-smokers (OR = 1.0, 95% CI: 0.8-1.3). The reduced risk of acoustic neuroma in smokers and raised risk in parous women might relate to sex hormone levels, or smoking might suppress tumor growth, but effects of parity and smoking on timing of diagnosis of the tumor are also a potential explanation. The raised risk in relation to past diagnosis of epilepsy might be a surveillance artefact or imply that epilepsy and/or antiepileptic medication use predispose to acoustic neuroma. These findings need replication by other studies and possible mechanisms need to be clarified.

Movement disorders in patients taking anticonvulsants

BACKGROUND

A wide variety of movement disorders may occur as a consequence of the administration of antiepileptic drugs (AEDs). Although it has been suggested that the risk of parkinsonism is 10-fold higher in those taking valproate as compared with other AEDs, there have been no large, systematic trials assessing this.

AIM

To establish more precisely the prevalence of and risk factors for developing parkinsonism associated with valproate use,and to assess the occurrence of movement disorders with the newer AEDs.

METHODS

Patients with epilepsy were recruited from the Toronto Western Hospital Epilepsy Clinic (University of Toronto, Toronto, Ontario, Canada). Each patient was examined by a movement disorder specialist who was blinded to the treatment status of the patient.

RESULTS

201 patients were included. Postural tremor was the most common movement disorder (45%), followed by parkinsonism (4.5%). The odds of having parkinsonism were 5 times higher with valproate than with other AEDs. No single factor predicted the presence of parkinsonism; however, many (5/9) of the patients concurrently used other drugs or had comorbidities that could have caused or exacerbated parkinsonism. None of the newer AEDs were clearly associated with the presence of movement disorders; however, the numbers were too small to make a formal analysis.

CONCLUSION

Although the risk of parkinsonism with valproate is higher than with other AEDs, it is lower than originally reported. The cases available were not enough to accurately comment on the prevalence of movement disorders with the newer AEDs.

Direct and Indirect Costs of Refractory Epilepsy in a Tertiary Epilepsy Center in Germany

PURPOSE

There are only few studies on the costs of epilepsy in Germany. Therefore, we performed a pilot study to estimate the direct and indirect costs of refractory epilepsy in a German epilepsy center.

METHODS

A "prevalence-based," cross-sectional convenience sample of adults with active epilepsy attending the outpatient clinic of our tertiary epilepsy center was evaluated. Seizure-free patients and patients presenting with their first seizure were excluded. Direct and indirect costs were prospectively recorded over a three-month period using questionnaires and a patient diary. Cost driving factors were identified.

RESULTS

One hundred one patients were included (40.7+/-15.2 years; disease duration: 18.1+/-15.3 years; 6 patients had focal epilepsy with simple partial seizures only, 28 with complex partial seizures, 43 with secondarily generalized tonic-clonic seizures; 20 had idiopathic generalized epilepsy with generalized tonic-clonic seizures). The total costs of epilepsy per patient were in average euro 2610+/-4200 over the three-month period. Direct cost contributed 39% to the total costs. Costs of anticonvulsant medication were the main contributor to the direct costs while indirect costs were caused mainly by losses due to early retirement. Cost driving factors included higher seizure frequency, longer disease duration, ictal falls, and situationally inappropriate complex behavior during or after the seizure.

CONCLUSIONS

Indirect costs were higher than direct costs in adult patients with active epilepsy attending a German epilepsy center. Medication contributed the most to the direct costs and early retirement was the main factor for the indirect costs. The costs of poorly controlled epilepsy in this German study were above average of the European costs of epilepsy.

Familial Risks for Epilepsy among Siblings Based on Hospitalizations in Sweden

PURPOSE

Epilepsy is a common disabling condition, with high heritability according to twin studies. Characterization of familial risks for common subtypes of epilepsy will advance the search for the heritable causes of these conditions and their underlying mechanisms. We aim at defining familial risks for siblings to be hospitalized because of epilepsy.

METHODS

A nationwide ad hoc epilepsy database was constructed by linking the Multigeneration Register on 0- to 69-year-old siblings to the Hospital Discharge Register for data on epilepsies covering the years 1987-2001. Standardized risk ratios (SIRs) were calculated for affected sibling pairs by comparing them to those whose siblings had no epilepsy.

RESULTS

Among a total of 26,799 hospitalized cases, 598 affected siblings were identified with a familial SIR of 2.35; the SIR was highest at ages 0-4 years (6.82). Infantile spasms showed the highest risk for any subtype (10.45), when a co-sibling was diagnosed with any epilepsy. When both siblings were diagnosed with a concordant (same) subtype of epilepsy, the SIRs were high, i.e. 8.43 for generalized idiopathic epilepsy, 2.56 for partial epilepsy, 24.72 for status epilepticus and 24.39 for other epilepsies. Generalized idiopathic epilepsy was also associated with grand mal (4.06) and other epilepsies (7.61). The numbers of cases were small but concordant diagnoses always showing higher SIRs compared with discordant diagnoses.

CONCLUSIONS

Within the limits of the present sample size, our results suggest high familial aggregation for certain subtypes of epilepsy for which distinct genetic mechanisms may underlie.

Population-based survey on prevalence of adult patients with epilepsy in Taiwan (Keelung community-based integrated screening no. 12)

PURPOSE

To determine the prevalence rate and patterns of adult patients with epilepsy in Taiwan, we conducted a community-based neuroepidemiological survey.

METHODS

Epilepsy was detected by neurologists using one-stage method. It was integrated into a community health screening service and performed from 1 January 2001 to 31 December 2001 in Keelung, a northern city in Taiwan. A total of 13,663 subjects aged 30 years or older participated in this survey.

RESULTS

There were 52 patients with epilepsy in this study. Among them, 37 were patients with active epilepsy. The age-adjusted prevalence rate of active epilepsy above 30 years old was 2.77/1000 (to the 1980 US population) with the highest rate in subjects aged 40-49 years (4.0/1000). There was a trend of higher prevalence rate in male than in female. The most common seizure type was complex partial seizure (46.0%). Using one-stage detection method, we found nine (24.3%) patients with active epilepsy who had never been diagnosed before. Among the patients with active epilepsy, 35.1% were symptomatic cases. Head injury (13.5%) is the leading cause, followed by CNS infection (8.1%), stroke (5.4%) and perinatal insult (5.4%). The lifetime prevalence rate of epilepsy (including active epilepsy and epilepsy in remission) was 3.14/1000 for age above 30 years.

CONCLUSIONS

Comparing to previous epilepsy survey in 1993, our results showed that the prevalence rate of epilepsy was rather stable over the past decade in northern Taiwan. Head injury is the leading cause responsible for active epilepsy. Improving public safety is an important public health issue which may help to reduce occurrence of epilepsy.

Increased sensitivity of the neuronal nicotinic receptor alpha 2 subunit causes familial epilepsy with nocturnal wandering and ictal fear

Sleep has traditionally been recognized as a precipitating factor for some forms of epilepsy, although differential diagnosis between some seizure types and parasomnias may be difficult. Autosomal dominant frontal lobe epilepsy is characterized by nocturnal seizures with hyperkinetic automatisms and poorly organized stereotyped movements and has been associated with mutations of the alpha 4 and beta 2 subunits of the neuronal nicotinic acetylcholine receptor. We performed a clinical and molecular genetic study of a large pedigree segregating sleep-related epilepsy in which seizures are associated with fear sensation, tongue movements, and nocturnal wandering, closely resembling nightmares and sleep walking. We identified a new genetic locus for familial sleep-related focal epilepsy on chromosome 8p12.3-8q12.3. By sequencing the positional candidate neuronal cholinergic receptor alpha 2 subunit gene (CHRNA2), we detected a heterozygous missense mutation, I279N, in the first transmembrane domain that is crucial for receptor function. Whole-cell recordings of transiently transfected HEK293 cells expressing either the mutant or the wild-type receptor showed that the new CHRNA2 mutation markedly increases the receptor sensitivity to acetylcholine, therefore indicating that the nicotinic alpha 2 subunit alteration is the underlying cause. CHRNA2 is the third neuronal cholinergic receptor gene to be associated with familial sleep-related epilepsies. Compared with the CHRNA4 and CHRNB2 mutations reported elsewhere, CHRNA2 mutations cause a more complex and finalized ictal behavior.

Adult epilepsy

The epilepsies are one of the most common serious brain disorders, can occur at all ages, and have many possible presentations and causes. Although incidence in childhood has fallen over the past three decades in developed countries, this reduction is matched by an increase in elderly people. Monogenic Mendelian epilepsies are rare. A clinical syndrome often has multiple possible genetic causes, and conversely, different mutations in one gene can lead to various epileptic syndromes. Most common epilepsies, however, are probably complex traits with environmental effects acting on inherited susceptibility, mediated by common variation in particular genes. Diagnosis of epilepsy remains clinical, and neurophysiological investigations assist with diagnosis of the syndrome. Brain imaging is making great progress in identifying the structural and functional causes and consequences of the epilepsies. Current antiepileptic drugs suppress seizures without influencing the underlying tendency to generate seizures, and are effective in 60-70% of individuals. Pharmacogenetic studies hold the promise of being able to better individualise treatment for each patient, with maximum possibility of benefit and minimum risk of adverse effects. For people with refractory focal epilepsy, neurosurgical resection offers the possibility of a life-changing cure. Potential new treatments include precise prediction of seizures and focal therapy with drug delivery, neural stimulation, and biological grafts.

Anti-epileptic drug phenytoin enhances androgen metabolism and androgen receptor expression in murine hippocampus

Epilepsy is very often related to strong impairment of neuronal networks, particularly in the hippocampus. Previous studies of brain tissue have demonstrated that long-term administration of the anti-epileptic drug (AED) phenytoin leads to enhanced metabolism of testosterone mediated by cytochrome P450 (CYP) isoforms. Thus, we speculate that AEDs affect androgen signalling in the hippocampus. In the present study, we investigated how the AED phenytoin influences the levels of testosterone, 17beta-oestradiol, and androgen receptor (AR) in the hippocampus of male C57Bl/6J mice. Phenytoin administration led to a 61.24% decreased hippocampal testosterone level as compared with controls, while serum levels were slightly enhanced. 17beta-Oestradiol serum level was elevated 2.6-fold. Concomitantly, the testosterone metabolizing CYP isoforms CYP3A11 and CYP19 (aromatase) have been found to be induced 2.4- and 4.2-fold, respectively. CYP3A-mediated depletion of testosterone-forming 2beta-, and 6beta-hydroxytestosterone was significantly enhanced. Additionally, AR expression was increased 2-fold (mRNA) and 1.8-fold (protein), predominantly in the CA1 region. AR was shown to concentrate in nuclei of CA1 pyramidal neurons. We conclude that phenytoin affects testosterone metabolism via induction of CYP isoforms. The increased metabolism of testosterone leading to augmented androgen metabolite formation most likely led to enhanced expression of CYP19 and AR in hippocampus. Phenytoin obviously modulates the androgen signalling in the hippocampus.

Epilepsy in Colombia: Epidemiologic Profile and Classification of Epileptic Seizures and Syndromes

PURPOSE

A national study was performed in Colombia to determine the general and regional prevalence of epilepsy, clinical profiles, seizure types, and clinical syndromes.

METHODS

Based on the National Epidemiological Study of Neurological Diseases (EPINEURO), we evaluated and followed up for 1 year all the subjects with epilepsy from the National Sample. Clinical profiles were further assessed. Seizure types and epilepsy syndromes were established according to the international classifications.

RESULTS

General prevalence was found to be 11.3 per 1,000, with little variation among regions, except the eastern region, where prevalence was 23 per 1,000; prevalence for active epilepsy was 10.1 per 1,000. Women have a slightly greater (not statistically significant) risk. Most seizures are focal (partial), frequently with secondary generalization. The most frequent epilepsy syndrome encountered was partial symptomatic/cryptogenic (80%). Epilepsy onset in Colombia occurs most frequently in childhood.

CONCLUSIONS

Prevalence rates of epilepsy in Colombia are similar to those reported in nations with comparable developmental status and have diminished over time. The study presents the distribution of seizures and syndromes. The most frequent types are focal syndromes.

Antidepressants and seizures: emphasis on newer agents and clinical implications

Seizures are a known, relatively rare, consequence of antidepressant treatment. Risk estimates vary depending on the study, source of data and patient population, predisposed vs. nonpredisposed. For newer antidepressants (e.g. selective serotonin reuptake inhibitors, bupropion, mirtazepine, etc.), the risk is generally considered to be low (0.0%-0.4%) and not very different from the incidence of first seizure in the general population (0.07%-0.09%). Risk with tricyclic antidepressants at effective therapeutic doses is relatively high (0.4% to 1-2%). Seizure following overdose is a significant and relatively frequent event for some antidepressants. Patients being considered for antidepressant treatment should be screened for predisposition to seizures. Predisposed patients should receive antidepressants cautiously. The seizure potential of antidepressants in patients without a predisposition is low, especially for newer antidepressants. Seizure risk, along with other drug-related considerations, e.g. weight gain, sexual dysfunction and sedation, should be considered when prescribing an antidepressant.

Depression and suicide attempt as risk factors for incident unprovoked seizures

Major depression has been shown to increase the risk for development of epilepsy, but prior studies have not evaluated whether this is due to specific symptoms of depression. We conducted a population-based case-control study of all newly diagnosed unprovoked seizures among Icelandic children and adults aged 10 years and older to test the hypothesis that major depression is a risk factor for developing unprovoked seizure and epilepsy, and to address whether specific symptoms of depression account for this increased risk. Cases were matched to the next two same sex births from the population registry. Using standardized interviews, we ascertained symptoms of major depression to make a Diagnostic and Statistical Manual, Fourth Edition (DSM-IV) diagnosis. A history of major depression was 1.7-fold more common among cases than among controls (95% confidence interval, 1.1-2.7). A history of attempted suicide was 5.1-fold more common among cases than among controls (95% confidence interval, 2.2-11.5). Attempted suicide increased seizure risk even after adjusting for age, sex, cumulative alcohol intake, and major depression or number of symptoms of depression. Major depression and attempted suicide independently increase the risk for unprovoked seizure. These data suggest that depression and suicide attempt may be due to different underlying neurochemical pathways, each of which is important in the development of epilepsy.

Levetiracetam add-on for drug-resistant localization related (partial) epilepsy

BACKGROUND

The majority of patients with epilepsy have a good prognosis and their seizures are well controlled by a single antiepileptic drug. However, up to 30% develop refractory seizures, particularly those with partial seizures. In this review, we summarise the current evidence regarding a new antiepileptic drug, levetiracetam, when used as an add-on treatment for drug-resistant localization related (partial) epilepsy.

OBJECTIVES

To evaluate the effects of levetiracetam on seizures, side effects, quality of life and cognition, when used as an add-on treatment for patients with a drug-resistant localization related (partial) epilepsy.

SEARCH STRATEGY

We searched the Cochrane Epilepsy Group trials register, the Cochrane Controlled Trials Register (Cochrane Library Issue 2, 2000). In addition, we contacted UCB SA (makers of levetiracetam) and experts in the field to seek any ongoing studies or unpublished studies.

SELECTION CRITERIA

Randomized placebo controlled add-on trials of levetiracetam in patients with a drug-resistant localization related (partial) epilepsy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion and extracted relevant data. The following outcomes were assessed: (a) 50% or greater reduction in total seizure frequency; (b) treatment withdrawal (any reason); (c) side effects; (d) cognitive effects; (e) quality of life. Primary analyses were intention to treat. Sensitivity best and worst case analyses were also undertaken. Summary odds ratios (ORs) were estimated for each outcome. Dose response was evaluated in regression models.

MAIN RESULTS

Four trials (1023 patients) were included. All four trials had data for treatment withdrawal and side effect outcomes. Three trials (904 patients) had data for 50% or greater reduction in seizure frequency. Three trials (595 patients) had data for quality of life and cognitive outcomes. The overall Odds Ratio (OR) (95% Confidence Interval (CI)) for 50% or greater reduction in total seizure frequency outcome was 3.81 (2.78,5.22). Dose regression analysis shows clear evidence that levetiracetam reduces seizure frequency with an increase in efficacy with increasing dose of levetiracetam. Approximately 15% of patients taking 1000 mg and 20-30% of patients taking 3000 mg levetiracetam per day have a 50% or greater reduction in seizure frequency. Patients were not significantly more likely to have levetiracetam withdrawn, OR (95% CI) 1.25 (0.87,1.80). The following side effects were significantly associated with levetiracetam: dizziness 2.36 (1.21, 4.61) and infection 1.82 (1.05, 3.14) whereas accidental injury was significantly associated with placebo 0.55 (0.32, 0.93). Quality of life and cognitive effect outcomes suggest that levetiracetam has a positive effect on cognition and some aspects of quality of life.

REVIEWER'S CONCLUSIONS

Levetiracetam reduces seizure frequency when used as an add-on treatment for patients with a drug-resistant localization related (partial) epilepsy, and seems well tolerated. Minimum effective and maximum tolerated doses have not been identified. The trials reviewed were of 16-24 weeks duration and results cannot be used to confirm longer term effects. Our results cannot be extrapolated to monotherapy or to patients with other seizure types or epilepsy syndromes. Great care should also be taken with any attempt to apply these results to children.