Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 35
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Lancet ; 397(10282): 1363-1374, 2021 04 10.
Article in English | MEDLINE | ID: mdl-33838757

ABSTRACT

BACKGROUND: Levetiracetam and zonisamide are licensed as monotherapy for patients with focal epilepsy, but there is uncertainty as to whether they should be recommended as first-line treatments because of insufficient evidence of clinical effectiveness and cost-effectiveness. We aimed to assess the long-term clinical effectiveness and cost-effectiveness of levetiracetam and zonisamide compared with lamotrigine in people with newly diagnosed focal epilepsy. METHODS: This randomised, open-label, controlled trial compared levetiracetam and zonisamide with lamotrigine as first-line treatment for patients with newly diagnosed focal epilepsy. Adult and paediatric neurology services across the UK recruited participants aged 5 years or older (with no upper age limit) with two or more unprovoked focal seizures. Participants were randomly allocated (1:1:1) using a minimisation programme with a random element utilising factor to receive lamotrigine, levetiracetam, or zonisamide. Participants and investigators were not masked and were aware of treatment allocation. SANAD II was designed to assess non-inferiority of both levetiracetam and zonisamide to lamotrigine for the primary outcome of time to 12-month remission. Anti-seizure medications were taken orally and for participants aged 12 years or older the initial advised maintenance doses were lamotrigine 50 mg (morning) and 100 mg (evening), levetiracetam 500 mg twice per day, and zonisamide 100 mg twice per day. For children aged between 5 and 12 years the initial daily maintenance doses advised were lamotrigine 1·5 mg/kg twice per day, levetiracetam 20 mg/kg twice per day, and zonisamide 2·5 mg/kg twice per day. All participants were included in the intention-to-treat (ITT) analysis. The per-protocol (PP) analysis excluded participants with major protocol deviations and those who were subsequently diagnosed as not having epilepsy. Safety analysis included all participants who received one dose of any study drug. The non-inferiority limit was a hazard ratio (HR) of 1·329, which equates to an absolute difference of 10%. A HR greater than 1 indicated that an event was more likely on lamotrigine. The trial is registered with the ISRCTN registry, 30294119 (EudraCt number: 2012-001884-64). FINDINGS: 990 participants were recruited between May 2, 2013, and June 20, 2017, and followed up for a further 2 years. Patients were randomly assigned to receive lamotrigine (n=330), levetiracetam (n=332), or zonisamide (n=328). The ITT analysis included all participants and the PP analysis included 324 participants randomly assigned to lamotrigine, 320 participants randomly assigned to levetiracetam, and 315 participants randomly assigned to zonisamide. Levetiracetam did not meet the criteria for non-inferiority in the ITT analysis of time to 12-month remission versus lamotrigine (HR 1·18; 97·5% CI 0·95-1·47) but zonisamide did meet the criteria for non-inferiority in the ITT analysis versus lamotrigine (1·03; 0·83-1·28). The PP analysis showed that 12-month remission was superior with lamotrigine than both levetiracetam (HR 1·32 [97·5% CI 1·05 to 1·66]) and zonisamide (HR 1·37 [1·08-1·73]). There were 37 deaths during the trial. Adverse reactions were reported by 108 (33%) participants who started lamotrigine, 144 (44%) participants who started levetiracetam, and 146 (45%) participants who started zonisamide. Lamotrigine was superior in the cost-utility analysis, with a higher net health benefit of 1·403 QALYs (97·5% central range 1·319-1·458) compared with 1·222 (1·110-1·283) for levetiracetam and 1·232 (1·112, 1·307) for zonisamide at a cost-effectiveness threshold of £20 000 per QALY. Cost-effectiveness was based on differences between treatment groups in costs and QALYs. INTERPRETATION: These findings do not support the use of levetiracetam or zonisamide as first-line treatments for patients with focal epilepsy. Lamotrigine should remain a first-line treatment for patients with focal epilepsy and should be the standard treatment in future trials. FUNDING: National Institute for Health Research Health Technology Assessment programme.


Subject(s)
Anticonvulsants/adverse effects , Cost-Benefit Analysis , Epilepsies, Partial/drug therapy , Lamotrigine/therapeutic use , Levetiracetam/therapeutic use , Treatment Outcome , Zonisamide/therapeutic use , Administration, Oral , Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Young Adult
2.
Lancet ; 397(10282): 1375-1386, 2021 04 10.
Article in English | MEDLINE | ID: mdl-33838758

ABSTRACT

BACKGROUND: Valproate is a first-line treatment for patients with newly diagnosed idiopathic generalised or difficult to classify epilepsy, but not for women of child-bearing potential because of teratogenicity. Levetiracetam is increasingly prescribed for these patient populations despite scarcity of evidence of clinical effectiveness or cost-effectiveness. We aimed to compare the long-term clinical effectiveness and cost-effectiveness of levetiracetam compared with valproate in participants with newly diagnosed generalised or unclassifiable epilepsy. METHODS: We did an open-label, randomised controlled trial to compare levetiracetam with valproate as first-line treatment for patients with generalised or unclassified epilepsy. Adult and paediatric neurology services (69 centres overall) across the UK recruited participants aged 5 years or older (with no upper age limit) with two or more unprovoked generalised or unclassifiable seizures. Participants were randomly allocated (1:1) to receive either levetiracetam or valproate, using a minimisation programme with a random element utilising factors. Participants and investigators were aware of treatment allocation. For participants aged 12 years or older, the initial advised maintenance doses were 500 mg twice per day for levetiracetam and valproate, and for children aged 5-12 years, the initial daily maintenance doses advised were 25 mg/kg for valproate and 40 mg/kg for levetiracetam. All drugs were administered orally. SANAD II was designed to assess the non-inferiority of levetiracetam compared with valproate for the primary outcome time to 12-month remission. The non-inferiority limit was a hazard ratio (HR) of 1·314, which equates to an absolute difference of 10%. A HR greater than 1 indicated that an event was more likely on valproate. All participants were included in the intention-to-treat (ITT) analysis. Per-protocol (PP) analyses excluded participants with major protocol deviations and those who were subsequently diagnosed as not having epilepsy. Safety analyses included all participants who received one dose of any study drug. This trial is registered with the ISRCTN registry, 30294119 (EudraCt number: 2012-001884-64). FINDINGS: 520 participants were recruited between April 30, 2013, and Aug 2, 2016, and followed up for a further 2 years. 260 participants were randomly allocated to receive levetiracetam and 260 participants to receive valproate. The ITT analysis included all participants and the PP analysis included 255 participants randomly allocated to valproate and 254 randomly allocated to levetiracetam. Median age of participants was 13·9 years (range 5·0-94·4), 65% were male and 35% were female, 397 participants had generalised epilepsy, and 123 unclassified epilepsy. Levetiracetam did not meet the criteria for non-inferiority in the ITT analysis of time to 12-month remission (HR 1·19 [95% CI 0·96-1·47]); non-inferiority margin 1·314. The PP analysis showed that the 12-month remission was superior with valproate than with levetiracetam. There were two deaths, one in each group, that were unrelated to trial treatments. Adverse reactions were reported by 96 (37%) participants randomly assigned to valproate and 107 (42%) participants randomly assigned to levetiracetam. Levetiracetam was dominated by valproate in the cost-utility analysis, with a negative incremental net health benefit of -0·040 (95% central range -0·175 to 0·037) and a probability of 0·17 of being cost-effectiveness at a threshold of £20 000 per quality-adjusted life-year. Cost-effectiveness was based on differences between treatment groups in costs and quality-adjusted life-years. INTERPRETATION: Compared with valproate, levetiracetam was found to be neither clinically effective nor cost-effective. For girls and women of child-bearing potential, these results inform discussions about benefit and harm of avoiding valproate. FUNDING: National Institute for Health Research Health Technology Assessment Programme.


Subject(s)
Epilepsy, Generalized/drug therapy , Levetiracetam/economics , Levetiracetam/therapeutic use , Valproic Acid/economics , Valproic Acid/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Anticonvulsants/economics , Anticonvulsants/therapeutic use , Child , Child, Preschool , Cost-Benefit Analysis , Female , Humans , Male , Middle Aged , Young Adult
3.
Hum Mol Genet ; 23(1): 247-58, 2014 Jan 01.
Article in English | MEDLINE | ID: mdl-23962720

ABSTRACT

We present the analysis of a prospective multicentre study to investigate genetic effects on the prognosis of newly treated epilepsy. Patients with a new clinical diagnosis of epilepsy requiring medication were recruited and followed up prospectively. The clinical outcome was defined as freedom from seizures for a minimum of 12 months in accordance with the consensus statement from the International League Against Epilepsy (ILAE). Genetic effects on remission of seizures after starting treatment were analysed with and without adjustment for significant clinical prognostic factors, and the results from each cohort were combined using a fixed-effects meta-analysis. After quality control (QC), we analysed 889 newly treated epilepsy patients using 472 450 genotyped and 6.9 × 10(6) imputed single-nucleotide polymorphisms. Suggestive evidence for association (defined as Pmeta < 5.0 × 10(-7)) with remission of seizures after starting treatment was observed at three loci: 6p12.2 (rs492146, Pmeta = 2.1 × 10(-7), OR[G] = 0.57), 9p23 (rs72700966, Pmeta = 3.1 × 10(-7), OR[C] = 2.70) and 15q13.2 (rs143536437, Pmeta = 3.2 × 10(-7), OR[C] = 1.92). Genes of biological interest at these loci include PTPRD and ARHGAP11B (encoding functions implicated in neuronal development) and GSTA4 (a phase II biotransformation enzyme). Pathway analysis using two independent methods implicated a number of pathways in the prognosis of epilepsy, including KEGG categories 'calcium signaling pathway' and 'phosphatidylinositol signaling pathway'. Through a series of power curves, we conclude that it is unlikely any single common variant explains >4.4% of the variation in the outcome of newly treated epilepsy.


Subject(s)
Epilepsy/diagnosis , Epilepsy/genetics , Genome-Wide Association Study , Adult , Anticonvulsants/therapeutic use , Calcium Signaling/genetics , Chromosomes, Human, Pair 15 , Chromosomes, Human, Pair 6 , Chromosomes, Human, Pair 9 , Epilepsy/drug therapy , Female , Genetic Predisposition to Disease , Genetic Variation , Humans , Male , Middle Aged , Phosphatidylinositols/genetics , Polymorphism, Single Nucleotide , Prognosis , Prospective Studies , Treatment Outcome , Young Adult
4.
J Neurol Neurosurg Psychiatry ; 84(7): 796-9, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23236017

ABSTRACT

AIM: To investigate antiepileptic drug (AED)-related weight changes in patients with epilepsy through a retrospective observational study. METHOD: We analysed the anonymised electronic primary care records of 1.1 million adult patients in Wales. We included patients aged 18 years and over with a diagnosis of epilepsy, whose body weight had been measured up to 12 months before starting, and between 3 and 12 months after starting, one of five AEDs. We calculated the weight difference after starting the AED for each patient. RESULTS: 1423 patients were identified in total. The mean difference between body weight after and before starting each AED (together with 95% CI and p values for no difference) were: carbamazepine (CBZ) 0.43 (-0.19 to 1.05) p=0.17; lamotrigine (LTG) 0.31 (-0.38 to 1.00) p=0.38; levetiracetam (LEV) 1.00 (0.16 to 1.84) p=0.02; sodium valproate (VPA) 0.74 (0.10 to 1.38) p=0.02; topiramate (TPM) -2.30 (-4.27 to -0.33) p=0.02. CONCLUSIONS: LEV and VPA were associated with significant weight gain, TPM was associated with significant weight loss, and LTG and CBZ were not associated with significant weight change.


Subject(s)
Anticonvulsants/adverse effects , Body Weight/drug effects , Epilepsy/complications , Adolescent , Adult , Aged , Anticonvulsants/therapeutic use , Comorbidity , Electronic Health Records , Epilepsy/drug therapy , Epilepsy/epidemiology , Female , Humans , Male , Middle Aged , Primary Health Care , Prospective Studies , Wales/epidemiology , Weight Gain/drug effects , Weight Loss/drug effects , Young Adult
5.
J Neurol Neurosurg Psychiatry ; 84(10): 1138-47, 2013 Oct.
Article in English | MEDLINE | ID: mdl-22933814

ABSTRACT

OBJECTIVE: To compare the effectiveness of levetiracetam (LEV) with extended-release sodium valproate (VPA-ER) and controlled-release carbamazepine (CBZ-CR) as monotherapy in patients with newly diagnosed epilepsy. METHODS: This unblinded, randomised, 52-week superiority trial (NCT00175903) recruited patients (≥16 years of age) with ≥2 unprovoked seizures in the previous 2 years and ≥1 in the previous 6 months. The physician chose VPA or CBZ as preferred standard treatment; each patient was randomised to standard treatment or LEV. The primary outcome was time to treatment withdrawal (LEV vs standard antiepileptic drugs (AEDs)). Analyses also compared LEV with VPA-ER, and LEV with CBZ-CR. FINDINGS: 1688 patients (mean age 41 years; 44% female) were randomised to LEV (n=841) or standard AEDs (n=847). Time to treatment withdrawal was not significantly different between LEV and standard AEDs: HR (95% CI) 0.90 (0.74 to 1.08). Time to treatment withdrawal (HR (95% CI)) was 1.02 (0.74 to 1.41) for LEV/VPA-ER and 0.84 (0.66 to 1.07) for LEV/CBZ-CR. Time to first seizure (HR, 95% CI) was significantly longer for standard AEDs, 1.20 (1.03 to 1.39), being 1.19 (0.93 to 1.54) for LEV/VPA-ER and 1.20 (0.99 to 1.46) for LEV/CBZ-CR. Estimated 12-month seizure freedom rates from randomisation: 58.7% LEV versus 64.5% VPA-ER; 50.5% LEV versus 56.7% CBZ-CR. Similar proportions of patients within each stratum reported at least one adverse event: 66.1% LEV versus 62.0% VPA-ER; 73.4% LEV versus 72.5% CBZ-CR. CONCLUSIONS: LEV monotherapy was not superior to standard AEDs for the global outcome, namely time to treatment withdrawal, in patients with newly diagnosed focal or generalised seizures.


Subject(s)
Anticonvulsants/therapeutic use , Carbamazepine/therapeutic use , Epilepsies, Partial/drug therapy , Epilepsy, Generalized/drug therapy , Piracetam/analogs & derivatives , Valproic Acid/therapeutic use , Adult , Anticonvulsants/adverse effects , Carbamazepine/adverse effects , Delayed-Action Preparations , Dose-Response Relationship, Drug , Drug Administration Schedule , Electroencephalography/drug effects , Epilepsies, Partial/diagnosis , Epilepsy, Generalized/diagnosis , Female , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Levetiracetam , Male , Middle Aged , Patient Dropouts , Piracetam/adverse effects , Piracetam/therapeutic use , Quality of Life , Signal Processing, Computer-Assisted , Valproic Acid/adverse effects
6.
Epilepsy Behav ; 29(3): 492-6, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24094841

ABSTRACT

We sought to understand the issues that lead from the need to change antiepileptic drugs (AEDs) and how this may influence someone's feelings regarding swapping to another drug. We conducted semistructured interviews with 14 people with epilepsy, four months after changing from AED monotherapy. Interviews were digitally recorded, transcripts were coded independently, and thematic analysis was undertaken through group work. There were seven major themes: failure, the reason behind the failure, and the experience itself; expectations; previous experience; personality and life events; side effects; impact of diagnosis; and outcome. Clinical outcome and patients' ideas of outcome were often discordant. Each drug change arises from a position of failure that elicits strong feelings of loss of control and vulnerability in participants. Recognizing the need for counseling of targeted individuals undergoing AED change is key. Unresolved emotional issues surrounding biographical disruption following diagnosis were potent modifiers of the change process.


Subject(s)
Anticonvulsants/therapeutic use , Epilepsy/diagnosis , Epilepsy/drug therapy , Adolescent , Adult , Aged , Electroencephalography , Epilepsy/psychology , Female , Humans , Interview, Psychological , Male , Middle Aged , Treatment Failure , Young Adult
7.
Front Bioeng Biotechnol ; 10: 895069, 2022.
Article in English | MEDLINE | ID: mdl-35814024

ABSTRACT

Cell-free protein synthesis (CFPS) is an in vitro process that enables diverse applications in research, biomanufacturing, point-of-care diagnostics, therapeutics, and education using minimal laboratory equipment and reagents. One of the major limitations of CFPS implementation is its sensitivity to plasmid type. Specifically, plasmid templates based on commonly used vector backbones such as the pET series of bacterial expression vectors result in the inferior production of proteins. To overcome this limitation, we have evaluated the effect of expression cassette elements present in the pET30 vector on protein production across three different CFPS systems: NEBExpress, PURExpress, and CFAI-based E. coli extracts. Through the systematic elimination of genetic elements within the pET30 vector, we have identified elements that are responsible for the poor performance of pET30 vectors in the various CFPS systems. As a result, we demonstrate that through the removal of the lac operator (lacO) and N-terminal tags included in the vector backbone sequence, a pET vector can support high titers of protein expression when using extract-based CFPS systems. This work provides two key advances for the research community: 1) identification of vector sequence elements that affect robust production of proteins; 2) evaluation of expression across three unique CFPS systems including CFAI extracts, NEBexpress, and PURExpress. We anticipate that this work will improve access to CFPS by enabling researchers to choose the correct expression backbone within the context of their preferred expression system.

8.
Pract Neurol ; 16(6): 428-430, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28120787
9.
J Vis Exp ; (173)2021 07 22.
Article in English | MEDLINE | ID: mdl-34369932

ABSTRACT

Cell-free protein synthesis (CFPS) has grown as a biotechnology platform that captures transcription and translation machinery in vitro. Numerous developments have made the CFPS platform more accessible to new users and have expanded the range of applications. For lysate based CFPS systems, cell extracts can be generated from a variety of organisms, harnessing the unique biochemistry of that host to augment protein synthesis. Within the last 20 years, Escherichia coli (E. coli) has become one of the most widely used organisms for supporting CFPS due to its affordability and versatility. Despite numerous key advances, the workflow for E. coli cell extract preparation has remained a key bottleneck for new users to implement CFPS for their applications. The extract preparation workflow is time-intensive and requires technical expertise to achieve reproducible results. To overcome these barriers, we previously reported the development of a 24 hour cell-free autoinduction (CFAI) workflow that reduces user input and technical expertise required. The CFAI workflow minimizes the labor and technical skill required to generate cell extracts while also increasing the total quantities of cell extracts obtained. Here we describe that workflow in a step-by-step manner to improve access and support the broad implementation of E. coli based CFPS.


Subject(s)
Escherichia coli , Protein Biosynthesis , Biotechnology , Cell-Free System/metabolism , Escherichia coli/genetics , Workflow
10.
Epilepsia ; 51(1): 48-56, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19583779

ABSTRACT

PURPOSE: To compare the cognitive profile of newly diagnosed untreated epilepsy patients with healthy volunteers using a comprehensive neuropsychological test battery. METHODS: A total of 155 untreated patients with newly diagnosed epilepsy, and no known brain pathology, were assessed before the start of treatment with antiepileptic medication. Their scores across the neuropsychological measures were compared with 87 healthy volunteers from the general population equated for age and sex. RESULTS: After adjusting for age, sex, and education, patients with epilepsy performed significantly worse than healthy volunteers on 6 of 14 cognitive measures, particularly in the domains of memory and psychomotor speed. Cognitive performance was not related to the number of seizures, type of epilepsy, or mood. When an impairment index was calculated, 53.5% patients had a least one abnormal score [>2 standard deviations (SD) below the control mean] on the test battery compared with 20.7% of healthy volunteers. DISCUSSION: Newly diagnosed untreated patients with epilepsy are cognitively compromised before the start of antiepileptic drug medication. The domains most affected are memory and psychomotor speed. More than one-half of the patients had at least one abnormal test score across the test battery. There were no differences in epilepsy-related or mood variables between those who demonstrated dysfunction and those that did not.


Subject(s)
Anticonvulsants/therapeutic use , Cognition Disorders/diagnosis , Epilepsy/drug therapy , Neuropsychological Tests/statistics & numerical data , Adult , Cognition Disorders/epidemiology , Comorbidity , Educational Status , Epilepsy/diagnosis , Epilepsy/epidemiology , Female , Humans , Longitudinal Studies , Male , Memory Disorders/diagnosis , Prospective Studies , Psychometrics , Psychomotor Performance , United Kingdom/epidemiology
11.
Ophthalmology ; 116(3): 565-71, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19168223

ABSTRACT

PURPOSE: To investigate whether nasal peripapillary retinal nerve fiber layer (RNFL) attenuation is associated with visual field loss attributed to the anti-epileptic drug vigabatrin. DESIGN: Prospective cross-sectional observational study. PARTICIPANTS: Twenty-seven individuals with focal-onset epilepsy exposed to vigabatrin and 13 individuals with focal-onset epilepsy exposed to non-GABAergic anti-epileptic drug monotherapy. METHODS: At one visit, suprathreshold perimetry of the central and peripheral field (3-zone, age-corrected Full Field 135 Screening Test) and threshold perimetry of the central field (Program 30-2 and the FASTPAC strategy) were undertaken using the Humphrey Field Analyzer (Carl Zeiss Meditech, Dublin, CA). At a second visit, ocular coherence tomography was undertaken for the right eye using the 3.4 RNFL thickness protocol of the StratusOCT (Carl Zeiss Meditech). MAIN OUTCOME MEASURES: The magnitude, for each individual, of the RNFL thickness, averaged across the 4 oblique quadrants, and for each separate quadrant. RESULTS: Of the 27 individuals exposed to vigabatrin, 11 (group I) exhibited vigabatrin-attributed visual field loss, 15 exhibited a normal field, and 1 exhibited a homonymous quadrantanopia (group II). All 13 individuals exposed to non-GABAergic therapy had normal fields (group III). All individuals in group I exhibited abnormal average and nasal quadrant RNFL thicknesses in the presence of a normal temporal quadrant thickness. Most also exhibited additional RNFL attenuation in either the superior or inferior quadrant, or both. Four individuals in group II exhibited an identical pattern of RNFL attenuation suggesting that nasal RNFL thinning is a more sensitive marker for vigabatrin toxicity than visual field loss. None of the 13 individuals in group III exhibited nasal quadrant RNFL attenuation. CONCLUSIONS: Vigabatrin-attributed visual field loss is associated with a characteristic pattern of RNFL attenuation: nasal quadrant thinning and normal temporal quadrant thickness with, or without, superior or inferior quadrant involvement. Nasal attenuation may precede visual field loss. Ocular coherence tomography of the peripapillary RNFL should be considered in patients previously exposed to vigabatrin. It should also be considered at baseline and follow-up in those commencing vigabatrin for treatment of epilepsy or in trials for anti-addiction therapy. The pattern of RNFL thinning seems to be a useful biomarker to identify vigabatrin toxicity.


Subject(s)
Anticonvulsants/adverse effects , Axons/pathology , Retinal Ganglion Cells/pathology , Vigabatrin/adverse effects , Vision Disorders/diagnosis , Visual Fields/drug effects , Adolescent , Adult , Aged , Axons/drug effects , Biomarkers , Carbamazepine/therapeutic use , Cross-Sectional Studies , Epilepsies, Partial/drug therapy , Female , Humans , Male , Middle Aged , Prospective Studies , Retinal Ganglion Cells/drug effects , Tomography, Optical Coherence , Vision Disorders/chemically induced , Visual Field Tests
12.
Epilepsia ; 50(2): 318-21, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18616557

ABSTRACT

The purpose of the study was to determine whether in utero exposure to vigabatrin caused visual field loss. Three mothers with four children who had been exposed to vigabatrin in utero and who were subsequently formula fed were identified. All seven individuals underwent perimetry and imaging of the retinal nerve fiber layer (RNFL). All individuals yielded reliable outcomes to perimetry and RNFL images of acceptable quality. Two of the three mothers exhibited vigabatrin-attributed visual field loss and an abnormally attenuated RNFL. The third exhibited an upper left quadrantanopia, consistent with previous temporal lobe surgery, and a normal RNFL. All four children yielded normal visual fields and RNFL thicknesses. The presence of the normal findings for the children is reassuring and, if representative, suggests a lack of vigabatrin visual toxicity and therefore obviates the need for ophthalmological examination of those exposed to vigabatrin prenatally.


Subject(s)
Anticonvulsants/adverse effects , Epilepsies, Partial/drug therapy , Pregnancy Complications/drug therapy , Prenatal Exposure Delayed Effects/chemically induced , Vigabatrin/adverse effects , Visual Fields/drug effects , Adolescent , Adult , Anticonvulsants/therapeutic use , Child , Dose-Response Relationship, Drug , Female , Follow-Up Studies , Humans , Long-Term Care , Male , Pregnancy , Retinal Neurons/drug effects , Tomography, Optical Coherence , Vigabatrin/therapeutic use , Visual Field Tests
14.
CNS Drugs ; 33(8): 817-829, 2019 08.
Article in English | MEDLINE | ID: mdl-31250314

ABSTRACT

BACKGROUND: The morphology and between-eye symmetry of the visual field loss associated with the antiepileptic drug vigabatrin (VAVFL) has received little attention. OBJECTIVE: Our objective was to model the appearance and ensuing staging of VAVFL derived with the European Medicines Agency-approved perimetric protocol. METHODS: This was a retrospective, cross-sectional, observational study that identified 123 adults who had received vigabatrin for refractory seizures and who had no evidence of co-existing retino-geniculo-cortical visual pathway abnormality. A further 38 adults with refractory seizures and identical inclusion criteria but no exposure to vigabatrin acted as controls. For each group, the median outcome at each stimulus location in each eye (of absolute loss, relative loss or Pattern Deviation probability level, as appropriate) was derived for each successive ten pairs of fields, ranked for severity. Between-eye symmetry was quantified by an index that accounted for severity of loss and that was referenced to the likelihood of the occurrence of symmetry due to chance. RESULTS: The modelled VAVFL was bilateral and highly symmetrical and was described by six stages that were all independent of the extent of vigabatrin exposure. The loss originated in the extreme temporal periphery and encroached centripetally along all meridians towards fixation. The initial appearance within the central field (Stage 2) occurred inferior-nasally. Subsequent stages exhibited increasing loss, which was greater nasally than temporally. Stage 6 described concentric loss extending to approximately 15° eccentricity from fixation. CONCLUSION: The model exhibited a consistent pattern of VAVFL. The staging of the loss could assist the risk:benefit analysis of vigabatrin for the treatment of epilepsy.


Subject(s)
Anticonvulsants/adverse effects , Anticonvulsants/therapeutic use , Vigabatrin/adverse effects , Vigabatrin/therapeutic use , Vision Disorders/chemically induced , Visual Fields/drug effects , Adult , Cross-Sectional Studies , Epilepsy/drug therapy , Female , Humans , Male , Retrospective Studies , Risk
15.
CNS Drugs ; 33(2): 161-173, 2019 02.
Article in English | MEDLINE | ID: mdl-30637668

ABSTRACT

BACKGROUND: The antiepileptic drug vigabatrin is associated with characteristic visual field loss (VAVFL) and thinning of the peripapillary retinal nerve fibre layer (PPRNFL); however, the relationship is equivocal. OBJECTIVE: The aim of this study was to determine the function-structure relationship associated with long-term exposure to vigabatrin, thereby improving the risk/benefit analysis of the drug. METHODS: A cross-sectional observational design identified 40 adults who had received long-term vigabatrin for refractory seizures, who had no evidence of co-existing retino-geniculo-cortical visual pathway abnormality, and who had undergone a standardized protocol of perimetry and of optical coherence tomography (OCT) of the PPRNFL. Vigabatrin toxicity was defined as the presence of VAVFL. The function-structure relationship for the superior and inferior retinal quadrants was evaluated by two established models applicable to other optic neuropathies. RESULTS: The function-structure relationship for each model was consistent with an optic neuropathy. PPRNFL thinning, expressed in micrometres, asymptoted at an equivalent visual field loss of worse than approximately - 10.0 dB, thereby preventing assessment of more substantial thinning. Transformation of the outcomes to retinal ganglion cell soma and axon estimates, respectively, resulted in a linear relationship. CONCLUSIONS: Functional and structural abnormality is strongly related in individuals with vigabatrin toxicity and no evidence of visual pathway comorbidity, thereby implicating retinal ganglion cell dysfunction. OCT affords a limited measurement range compared with perimetry: severity cannot be directly assessed when the PPRNFL quadrant thickness is less than approximately 65 µm, depending on the tomographer. This limitation can be overcome by transformation of thickness to remaining axons, an outcome requiring input from perimetry.


Subject(s)
Anticonvulsants/adverse effects , Nerve Fibers/drug effects , Retinal Ganglion Cells/drug effects , Vigabatrin/adverse effects , Vision Disorders/chemically induced , Visual Fields/drug effects , Adult , Anticonvulsants/administration & dosage , Cohort Studies , Cross-Sectional Studies , Dose-Response Relationship, Drug , Female , Humans , Male , Middle Aged , Nerve Fibers/pathology , Retinal Ganglion Cells/pathology , Time Factors , Tomography, Optical Coherence , Vigabatrin/administration & dosage , Vision Disorders/diagnostic imaging , Vision Disorders/pathology , Visual Field Tests
16.
Lancet ; 369(9566): 1000-15, 2007 Mar 24.
Article in English | MEDLINE | ID: mdl-17382827

ABSTRACT

BACKGROUND: Carbamazepine is widely accepted as a drug of first choice for patients with partial onset seizures. Several newer drugs possess efficacy against these seizure types but previous randomised controlled trials have failed to inform a choice between these drugs. We aimed to assess efficacy with regards to longer-term outcomes, quality of life, and health economic outcomes. METHODS: SANAD was an unblinded randomised controlled trial in hospital-based outpatient clinics in the UK. Arm A recruited 1721 patients for whom carbamazepine was deemed to be standard treatment, and they were randomly assigned to receive carbamazepine, gabapentin, lamotrigine, oxcarbazepine, or topiramate. Primary outcomes were time to treatment failure, and time to 12-months remission, and assessment was by both intention to treat and per protocol. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN38354748. FINDINGS: For time to treatment failure, lamotrigine was significantly better than carbamazepine (hazard ratio [HR] 0.78 [95% CI 0.63-0.97]), gabapentin (0.65 [0.52-0.80]), and topiramate (0.64 [0.52-0.79]), and had a non-significant advantage compared with oxcarbazepine (1.15 [0.86-1.54]). For time to 12-month remission carbamazepine was significantly better than gabapentin (0.75 [0.63-0.90]), and estimates suggest a non-significant advantage for carbamazepine against lamotrigine (0.91 [0.77-1.09]), topiramate (0.86 [0.72-1.03]), and oxcarbazepine (0.92 [0.73-1.18]). In a per-protocol analysis, at 2 and 4 years the difference (95% CI) in the proportion achieving a 12-month remission (lamotrigine-carbamazepine) is 0 (-8 to 7) and 5 (-3 to 12), suggesting non-inferiority of lamotrigine compared with carbamazepine. INTERPRETATION: Lamotrigine is clinically better than carbamazepine, the standard drug treatment, for time to treatment failure outcomes and is therefore a cost-effective alternative for patients diagnosed with partial onset seizures.


Subject(s)
Anticonvulsants/therapeutic use , Epilepsies, Partial/drug therapy , Quality of Life , Adolescent , Adult , Anticonvulsants/adverse effects , Anticonvulsants/economics , Child , Cost-Benefit Analysis , Epilepsies, Partial/classification , Female , Humans , Male , Treatment Outcome
17.
Lancet ; 369(9566): 1016-26, 2007 Mar 24.
Article in English | MEDLINE | ID: mdl-17382828

ABSTRACT

BACKGROUND: Valproate is widely accepted as a drug of first choice for patients with generalised onset seizures, and its broad spectrum of efficacy means it is recommended for patients with seizures that are difficult to classify. Lamotrigine and topiramate are also thought to possess broad spectrum activity. The SANAD study aimed to compare the longer-term effects of these drugs in patients with generalised onset seizures or seizures that are difficult to classify. METHODS: SANAD was an unblinded randomised controlled trial in hospital-based outpatient clinics in the UK. Arm B of the study recruited 716 patients for whom valproate was considered to be standard treatment. Patients were randomly assigned to valproate, lamotrigine, or topiramate between Jan 12, 1999, and Aug 31, 2004, and follow-up data were obtained up to Jan 13, 2006. Primary outcomes were time to treatment failure, and time to 1-year remission, and analysis was by both intention to treat and per protocol. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN38354748. FINDINGS: For time to treatment failure, valproate was significantly better than topiramate (hazard ratio 1.57 [95% CI 1.19-2.08]), but there was no significant difference between valproate and lamotrigine (1.25 [0.94-1.68]). For patients with an idiopathic generalised epilepsy, valproate was significantly better than both lamotrigine (1.55 [1.07-2.24] and topiramate (1.89 [1.32-2.70]). For time to 12-month remission valproate was significantly better than lamotrigine overall (0.76 [0.62-0.94]), and for the subgroup with an idiopathic generalised epilepsy 0.68 (0.53-0.89). But there was no significant difference between valproate and topiramate in either the analysis overall or for the subgroup with an idiopathic generalised epilepsy. INTERPRETATION: Valproate is better tolerated than topiramate and more efficacious than lamotrigine, and should remain the drug of first choice for many patients with generalised and unclassified epilepsies. However, because of known potential adverse effects of valproate during pregnancy, the benefits for seizure control in women of childbearing years should be considered.


Subject(s)
Anticonvulsants/therapeutic use , Cost-Benefit Analysis , Epilepsy, Generalized/drug therapy , Fructose/analogs & derivatives , Triazines/therapeutic use , Valproic Acid/therapeutic use , Adolescent , Adult , Anticonvulsants/adverse effects , Anticonvulsants/economics , Child , Child, Preschool , Epilepsy, Generalized/physiopathology , Epilepsy, Generalized/prevention & control , Female , Follow-Up Studies , Fructose/adverse effects , Fructose/therapeutic use , Humans , Lamotrigine , Male , Quality-Adjusted Life Years , Time Factors , Topiramate , Treatment Failure , Triazines/adverse effects , Valproic Acid/adverse effects
18.
Invest Ophthalmol Vis Sci ; 47(3): 917-24, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16505024

ABSTRACT

PURPOSE: To quantify retinal nerve fiber layer thickness (RNFLT) and macular thickness (MT) in patients exhibiting vigabatrin-attributed visual field loss (VAVFL) and to determine the efficacy of these measures as markers of the retinal damage associated with vigabatrin. METHODS: This was a prospective cross-sectional observational study involving five groups: Group I, 13 patients exhibiting VAVFL; Group II, 8 patients exposed to vigabatrin but with normal fields; Group III, 14 patients receiving carbamazepine monotherapy; Group IV, 20 normal individuals; and Group V, 7 patients receiving sodium valproate monotherapy. At one of two visits, the right eye of each participant underwent two digital imaging modalities: ocular coherence tomography (OCT; StratusOCT; Carl Zeiss Meditec, Dublin, CA) and scanning laser ophthalmoscopy (SLO; Heidelberg Retinal Tomograph; Heidelberg Engineering GmbH, Heidelberg, Germany). At the other visit, participants underwent three-zone, age-corrected suprathreshold perimetry of the whole field and threshold perimetry of the central field (Humphrey Field Analyzer 750; Carl Zeiss Meditec). The order of the visits was randomized. RESULTS: The group mean RNFLT in Group I was attenuated relative to that of the remaining groups (all P < 0.001). At 100% specificity, based on the 95% confidence limits derived from Group IV, OCT exhibited 100% sensitivity and SLO 77% sensitivity for an attenuated RNFLT in patients with VAVFL. All participants manifested an MT within the normal range derived from Group IV. CONCLUSIONS: OCT of the RNFL can efficiently identify vigabatrin-induced damage and will be useful for adults and children unable to perform perimetry and when the perimetric outcome is equivocal.


Subject(s)
Anticonvulsants/adverse effects , Nerve Fibers/pathology , Retinal Ganglion Cells/pathology , Vigabatrin/adverse effects , Vision Disorders/diagnosis , Visual Fields/drug effects , Adult , Carbamazepine/therapeutic use , Cross-Sectional Studies , Epilepsy/drug therapy , Female , Humans , Male , Nerve Fibers/drug effects , Ophthalmoscopy , Prospective Studies , Retinal Ganglion Cells/drug effects , Sensitivity and Specificity , Tomography, Optical Coherence , Valproic Acid/therapeutic use , Vision Disorders/chemically induced , Visual Field Tests
20.
J Am Coll Dent ; 73(4): 18-21, 2006.
Article in English | MEDLINE | ID: mdl-17585729

ABSTRACT

State dental associations must be responsive to the unique needs of the public and dentists in each state. The South Carolina Dental Association has a tradition of proactively partnering with the legislature and others to promote the long-range oral health of the state. Issues of access, licensure, and fair reimbursement are important concerns. SCDA has taken the lead in these areas, as well as in understanding the needs of new dentists, providing services for dentists as part of a non-dues financial structure, and advocating for the interests of individual practitioners.


Subject(s)
Dental Care/economics , Societies, Dental/organization & administration , Dentistry , Health Services Accessibility/legislation & jurisprudence , Humans , Societies, Dental/economics , South Carolina
SELECTION OF CITATIONS
SEARCH DETAIL