Ring and peg electrodes for minimally-Invasive and long-term sub-scalp EEG recordings.

OBJECTIVE: Minimally-invasive approaches are needed for long-term reliable Electroencephalography (EEG) recordings to assist with epilepsy diagnosis, investigation and more naturalistic monitoring. This study compared three methods for long-term implantation of sub-scalp EEG electrodes. METHODS: Three types of electrodes (disk, ring, and peg) were fabricated from biocompatible materials and implanted under the scalp in five ambulatory ewes for 3months. Disk electrodes were inserted into sub-pericranial pockets. Ring electrodes were tunneled under the scalp. Peg electrodes were inserted into the skull, close to the dura. EEG was continuously monitored wirelessly. High resolution CT imaging, histopathology, and impedance measurements were used to assess the status of the electrodes at the end of the study. RESULTS: EEG amplitude was larger in the peg compared with the disk and ring electrodes (p<0.05). Similarly, chewing artifacts were lower in the peg electrodes (p<0.05). Electrode impedance increased after long-term implantation particularly for those within the bone (p<0.01). Micro-CT scans indicated that all electrodes stayed within the sub-scalp layers. All pegs remained within the burr holes as implanted with no evidence of extrusion. Eight of 10 disks partially eroded into the bone by 1.0mm from the surface of the skull. The ring arrays remained within the sub-scalp layers close to implantation site. Histology revealed that the electrodes were encapsulated in a thin fibrous tissue adjacent to the pericranium. Overlying this was a loose connective layer and scalp. Erosion into the bone occurred under the rim of the sub-pericranial disk electrodes. CONCLUSIONS: The results indicate that the peg electrodes provided high quality EEG, mechanical stability, and lower chewing artifact. Whereas, ring electrode arrays tunneled under the scalp enable minimal surgical techniques to be used for implantation and removal.

A comprehensive assessment of cognitive function in the common genetic generalized epilepsy syndromes.

BACKGROUND AND PURPOSE: Considered to be benign conditions, the common genetic generalized epilepsy (GGE) syndromes are now known to be frequently accompanied by cognitive dysfunction. However, unresolved issues impede clinical management of this common comorbidity, including which cognitive abilities are most affected, whether there are differences between syndromes and how seizure type and mood symptoms affect cognitive dysfunction. We provide a detailed description of cognitive ability and evaluate factors contributing to cognitive dysfunction. METHODS: A total of 76 adults with GGE were assessed with the Woodcock Johnson III Tests of Cognitive Abilities. RESULTS: Scores on tests of overall cognitive ability, acquired knowledge, long-term retrieval and speed of information processing were significantly below the normative mean. Long-term retrieval was a pronounced weakness with a large reduction in scores (d = 0.84). GGE syndrome, seizure type and the presence of recent psychopathology symptoms were not significantly associated with cognitive function. CONCLUSIONS: This study confirms previous meta-analytic findings with a prospective study, offers new insights into the cognitive comorbidity of these common epilepsy syndromes and reinforces the need for cognitive interventions in people with GGE.

Role of demographic and job-related variables in determining work-related quality of life of hospital employees.

BACKGROUND: Considering a huge working population in health sector faced with stressful work life, limited autonomy in work and declining work contentment calls for an overemphasis on evaluating and monitoring their satisfaction associated with work-related quality of life (WRQoL). This study evaluates WRQoL of hospital employees and validates the bilingual (English and Marathi) version of WRQoL scale. METHODS: The study was conducted during March-April'2014 on employees of a corporate hospital of Pune, India after ethical approval and informed consent from employees. The bilingual WRQoL scale has been tested for reliability and validity, and WRQoL scores have been reported. RESULTS: A total of 132 hospital employees (mean age 31 [±8] years, 55% males) who participated in the study reported overall moderate WRQoL scores. The scale showed high internal consistency (Cronbach's alpha = 0.82, P < 0.0001) and moderate to high validity. WRQoL did not significantly vary across marital status, family size, and gender. "Stress at work" score of WRQoL increased with age of employees. Higher work experience, employment at higher positions and those working in clinical and diagnostic departments reported a higher WRQoL. CONCLUSION: WRQoL scale is a reliable and valid instrument. Better WRQoL in employees placed in higher organizational positions indicates a need for focused measures to enhance WRQoL of employees in lower hierarchical levels, especially in control at work and home life interface domains. WRQoL needs regular monitoring for employees in lower positions and aging employees.

A Systematic Review of Psychiatric and Psychosocial Comorbidities of Genetic Generalised Epilepsies (GGE).

Psychiatric disorders and associated poor psychosocial outcomes are recognised to be a common sequelae of epilepsy. The extent to which this is true of genetic generalised epilepsies (GGE), particularly syndromes other than juvenile myoclonic epilepsy (JME) is unclear. This systematic review synthesises findings regarding psychiatric and associated comorbidities in adults and children with GGE. Systematic review yielded 34 peer-reviewed studies of psychiatric and psychosocial outcomes in adults and children with GGE. Clinically significant psychiatric comorbidity was reported in over half of all children and up to a third of all adults with GGE. There was no evidence to support the presence of personality traits specific to JME or other syndromes; rather rates mirrored community samples. A small number of studies report poor psychosocial outcomes in GGE, however the interpretation of these findings is limited by paucity of healthy comparison groups. Some evidence suggests that anti-epileptic drug polytherapy in children and seizure burden at all ages may constitute risk factors for psychopathology. Findings highlight the importance of early screening so as not to overlook early or developing symptoms of psychopathology.

Pre-Chemoradiotherapy FDG PET/CT cannot Identify Residual Metabolically-Active Volumes within Individual Esophageal Tumors.

OBJECTIVE: To study whether subvolumes with a high pre-chemoradiotherapy (CRT) FDG uptake could identify residual metabolically-active volumes (MAVs) post-CRT within individual esophageal tumors. Accurate identification will allow simultaneous integrated boost to these subvolumes at higher risk to improve clinical outcomes. METHODS: Twenty patients with esophageal cancer were treated with CRT plus surgery and underwent FDG PET/CT scans before and after CRT. The two scans were rigidly registered. Seven MAVs pre-CRT and four MAVs post-CRT within a tumor were defined with various SUV thresholds. The similarity and proximity between the MAVs pre-CRT and post-CRT were quantified with three metrics: fraction of post-CRT MAV included in pre-CRT MAV, volume overlap and centroid distance. RESULTS: Eight patients had no residual MAV. Six patients had local residual MAV (SUV ≥2.5 post-CRT) within or adjoining the original MAV (SUV ≥2.5 pre-CRT). On average, less than 65% of any post-CRT MAVs was included in any pre-CRT MAVs, with a low volume overlap <45%, and large centroid distance >8.6 mm. In general, subvolumes with higher FDG-uptake pre-CRT or post-CRT had lower volume overlap and larger centroid distance. Six patients had new distant MAVs that were determined to be inflammation from radiation therapy. CONCLUSIONS: Pre-CRT PET/CT cannot reliably identify the residual MAVs within individual esophageal tumors. Simultaneous integrated boost to subvolumes with high FDG uptake pre-CRT may not be feasible.

Cognitive functioning in idiopathic generalised epilepsies: a systematic review and meta-analysis.

Cognitive function in idiopathic generalised epilepsies (IGE) is of increasing research attention. Current research seeks to understand phenotypic traits associated with this most common group of inherited epilepsies and evaluate educational and occupational trajectories. A specific deficit in executive function in a subgroup of IGE, juvenile myoclonic epilepsy (JME) has been a particular focus of recent research. This systematic review provides a quantitative synthesis of cognitive function outcomes in 26 peer-reviewed, case-control studies published since 1989. Univariate random-effects meta-analyses were conducted on seven cognitive factor-domains and separately on executive function. Patients with IGE demonstrated significantly lower scores on tests across all cognitive factor-domains except visual-spatial abilities. Effect sizes ranged from 0.42 to 0.88 pooled standard deviation units. The average reduction of scores on tests of executive function in IGE compared to controls was 0.72 standard deviation units. Contrary to current thinking, there was no specific deficit in executive function in JME samples, nor in other IGE syndromes. Of more concern, people with IGE are at risk of pervasive cognitive impairment.

Seizures during high-dose antidepressant therapy: a case series with clinical and video-electroencephalography characteristics.

This case series identified drug causes of seizures in patients with depressive disorders. Three patients with seizures were admitted for video-electroencephalography (EEG) monitoring in the context of high-dose antidepressants and sodium valproate. Very high-dose antidepressants caused complex partial seizures with secondary generalisation that gave characteristic EEG discharges. This is the first reported series to capture the ictal EEG features associated with antidepressants.

Beam controlled arc therapy--a delivery concept for stationary targets.

Volumetric modulated arc therapy (VMAT) presupposes that it is beneficial to deliver radiation from all beam angles as the gantry rotates, requiring the multi-leaf collimator to maintain continuity in shape from one angle to another. In turn, radiation from undesirable beam angles could compromise the dose distribution. In this work, we challenge the notion that the radiation beam must be held on as the gantry rotates around the patient. We propose a new approach for delivering intensity-modulated arc therapy, beam-controlled arc therapy (BCAT), during which the radiation beam is controlled on or off and the dose rate is modulated while the gantry rotates around the patient. We employ linear-programming-based dose optimization to each aperture weight, resulting in some zero weight apertures. During delivery, the radiation beam is held off at control points with zero weights as the MLC shape transits to the next non-zero weight shape. This was tested on ten head and neck cases. Plan quality and delivery efficiency were compared with VMAT. Improvements of up to 17% (p-value 0.001) and 57% (p-value 0.018) in organ-at-risk sparing and target dose uniformity, respectively, were achieved. Compared to the fixed number of apertures used in single-arc and double-arc VMAT, the BCAT used 109 and 175 apertures on average, respectively. The difference in total MUs for VMAT and BCAT plans was less than 4%. Plan quality improvement was confirmed after delivery with γ analysis resulting in over 99% agreement, or 4 in 1099 points that failed.

A surrogate-based metaheuristic global search method for beam angle selection in radiation treatment planning.

An important element of radiation treatment planning for cancer therapy is the selection of beam angles (out of all possible coplanar and non-coplanar angles in relation to the patient) in order to maximize the delivery of radiation to the tumor site and minimize radiation damage to nearby organs-at-risk. This category of combinatorial optimization problem is particularly difficult because direct evaluation of the quality of treatment corresponding to any proposed selection of beams requires the solution of a large-scale dose optimization problem involving many thousands of variables that represent doses delivered to volume elements (voxels) in the patient. However, if the quality of angle sets can be accurately estimated without expensive computation, a large number of angle sets can be considered, increasing the likelihood of identifying a very high quality set. Using a computationally efficient surrogate beam set evaluation procedure based on single-beam data extracted from plans employing equallyspaced beams (eplans), we have developed a global search metaheuristic process based on the nested partitions framework for this combinatorial optimization problem. The surrogate scoring mechanism allows us to assess thousands of beam set samples within a clinically acceptable time frame. Tests on difficult clinical cases demonstrate that the beam sets obtained via our method are of superior quality.

Clinical experience with using lacosamide for the treatment of epilepsy in a tertiary centre.

OBJECTIVE: Lacosamide is approved for the adjunctive treatment of partial-onset seizures in adults. Phase II/III clinical trials suggest that it is a safe, effective and well-tolerated medication. However, there is little post-marketing information available about this medication. METHODS: We report our clinical experience from a tertiary referral epilepsy centre, which has been using lacosamide for the past 18 months, with 128 patients treated during this time. RESULTS: Fifty-three patients (41%) achieved at least a 50% reduction in seizure frequency, with 14 patients (11%) achieving seizure freedom for a mean time of 35 weeks. This 50% responder rate matches, and the seizure free rate outperforms that seen in previous pooled trials. The efficacy of lacosamide did not vary with concurrent sodium channel blocking agent (SCB) use, and a statistically significant dose-dependent response was not shown, which is in contrast to previous trials. Treatment emergent adverse effects (TEAEs) were noted in 52 patients (41%), with 24 patients (19%) discontinuing the medication. TEAEs were more frequent in patients on concurrent SCBs, affecting 51% vs. 28% of patients not on other SCBs. This increased risk of TEAEs from concurrent SCB use was of statistical significance (P = 0.01). The most frequently noted TEAEs from lacosamide were dizziness, sedation and diplopia, which all appeared to be dose-related. CONCLUSION: This post-marketing analysis suggests that lacosamide in clinical practice at least mirrors, and possibly outperforms the results seen in previous phase II/III trials.

The prevalence and demographic distribution of treated epilepsy: a community-based study in Tasmania, Australia.

OBJECTIVES: To estimate the prevalence and demographic distribution of treated epilepsy in a community-based population. MATERIALS & METHODS: We surveyed all residents in Tasmania, Australia, who were supplied at least one antiepileptic drug prescription between July 1, 2001 and June 30, 2002, recorded on the national prescription database. We adjusted for the effect of disease-related non-response bias by imputation methods. RESULTS: After three mail contacts, 54.0% (4072/7541) responded, with 1774 (43.6%) indicating treatment for epilepsy, representing 86.0% of the estimated total possible cases in Tasmania. The adjusted treated epilepsy prevalence was 4.36 per 1000 (95% CI 4.34, 4.39); lower in women (prevalence ratio 0.92 (95% CI 0.84, 1.00)); greater with increasing age (P < 0.001); similar in the three main geographic regions; and similar with socioeconomic status of postcode of residence. CONCLUSIONS: Although our estimates are likely to be affected by access to health services, overall treated epilepsy prevalence of 4.4 per 1000 is similar to previous studies. Our finding of high elderly prevalence has been reported in a few recent studies in developed countries and has important clinical and public health implications in populations with similar aging demographics.

TU-E-BRA-10: Personalized Utility Function for Radiotherapy Based on Pulmonary Ventilation of Locally Advanced Lung Cancer Patients.

PURPOSE: To develop tailor-made utility functions based on each patient's pulmonary function distribution so that personalized organ-function-based treatment plan is obtained for locally advanced lung cancer patients. METHODS: Five locally advanced lung cancer patients were retrospectively evaluated in the study. Fractional regional ventilation was obtained by performing subtraction of spatially matched and corrected 4DCT images. Histogram of the fraction ventilation values was generated for each patient. The cumulative distribution function (CDF), which represented an inverse relationship with the desired dose to each voxel for function preservation, showed potential as personalized utility function. In order to spare the majority of the volume with pulmonary function, a more aggressive utility function was defined as a piece-wise linear function based on the most frequent fractional ventilation value (peak of the histogram). This utility function was used in the objective function during treatment planning. Conventional objectives and constraints were maintained during the planning process. RESULTS: Both conventional plan and personalized functional plan were classified as satisfactory plans by physician based on conventional dose and dose-volume metrics. However, functional plan successfully spared high ventilation volume based on each patient's unique condition. When spatial function information was included to collect function dose/dose-volume metrics, significant reduction of fV20, fV30 and mean lung dose was achieved by function-based personalized plan with p-value < 0.01. CONCLUSIONS: Organ-function-based radiotherapy has been presented to incorporate patient's pulmonary function in hopes of reducing the risk of complications. Current methods utilize the function information in the same fashion across patients. We took one step further to not only incorporate heterogeneous pulmonary function during treatment planning but also generate personalized utility function based on the function distribution of each patient. AAPM Research Seed Funding Initiative.

SU-E-J-111: Compute the Optimal Threshold for PET Functional Volume Delineation.

PURPOSE: To construct a method being able to compute the optimal threshold (OT) directly from PET images for functional volume delineation without any a priori information about scanners, imaging protocols and tumor size. METHODS: A mathematic model for partial volume effect (PVE) was analyzed for a spherical object with a constant activity imaged by a scanner with Gaussian point spread function (PSF). The theoretic analysis showed that information about some factors that are related to the PVE such as the PSF and tumor size had been actually embedded into PET images. We developed a new concept - the Optimal Area Ratio (OAR) that is a function of the object radius and can be derived from the model with some mathematic manipulations. With this new concept, information about PSF and tumor size can be recovered directly from PET images, and the OT can be calculated accordingly. The basic idea is to use the whole dynamic behavior (the behavior of the volume sizes due to different thresholds uniformly distributed in [0,1]) of a region-growing algorithm to find the OT. A computer simulation and experiments on phantoms with different object sizes and different noise levels were conducted to evaluate the above theoretic analysis. RESULTS: For the computer simulation, the calculated OT was exactly the real OT. In the experiments on phantoms, the calculated OT led to visually satisfactory delineation results. CONCLUSIONS: The new theoretic analysis showed that the OT can be calculated without any a priori information about scanners, imaging protocols and tumor size. The computer simulation and phantom experiments validated the theoretic analysis.

SU-E-T-611: Utilizing Machine Learning Techniques for Beam Angle Selection in Radiation Treatment Planning.

PURPOSE: To utilize machine learning techniques within beam angle optimization to determine an optimal Intensity-modulated radiation therapy (IMRT) beam angle set. METHODS: The input data were derived from a collection of equally-spaced seven-beam plans (e-plans) generated using the Pinnacle. This collection of e-plans contains all 72 beam angles corresponding to 5 degree spacing, and the dose delivered to patient tissues from each of these 72 angles was extracted to generate p-scores. Equally-spaced beam sets are commonly used in clinical practice, so this set of plans not only provides initial input data for our beam angle selection (BAS) procedure, but also provides a good set of benchmarks against which treatment improvement may be measured. A beam set scoring function was developed based on a weighted sum of overdose/underdose criteria. The Nested Partitions (NP) global optimization framework is then utilized to guide a sample-based search for the global optimal of the beam angle space. In our NP-based approach to BAS, a single sample is a 7-beam set satisfying beam spacing constraints. A fast scoring method based on the e-plan single-beam dose data was used to obtain an initial approximate score (c-score) and a set of dose component scores for each beam set. Machine learning techniques were then employed to predict each dose component, and these values were used to compute a predicted score. RESULTS: The average improvements in p-scores for 5 cases were 43%, 29% and 11% comparing to default eplan, best eplan and conventional NP (without ML). 10%, 12% and 15% improvement was achieved for sparing of spinal cord, brain stem and oral mucosa, respectively. CONCLUSIONS: Machine learning tools provide an effective technique for rapid high-quality approximate scoring for beam angle sets in IMRT. This approximation process leads to excellent beam sets when embedded within the NP global optimization framework. This work was supported in part by a grant from the NIH/NCI CA130814.

SU-E-T-399: Dosimetric and Geometric Evaluation of a Novel Stereotactic Radiotherapy Device for Breast Cancer: The GammaPod.

PURPOSE: A dedicated stereotactic irradiation device, the GammaPodTM, was developed to treat early stage breast cancer. This study presents the first description of the dosimetric and geometric characteristics from the prototype unit. METHODS: The GammaPod stereotactic radiotherapy device is an assembly of a hemi-spherical source carrier containing 36 Co-60 sources, a tungsten collimator, a dynamically controlled treatment table and a breast immobilization cup embedded with a stereotactic coordinate system. The source carrier and the variable-size collimator rotate synchronously to form 36 non-coplanar, concentric arcs focused at the isocenter. The treatment table enables motion in three dimensions facilitating continuous dose painting in comparison to a sphere packing approach. Geometric and dosimetric evaluations and a method for absorbed dose calibration are provided. Dosimetric verifications of the dynamically delivered plans are performed for eight patients in hypothetical pre-op, post-op and dose painting treatment scenarios. RESULTS: Loaded with a cumulative activity of 4320 Ci, the GammaPod unit delivers 5.31 Gy/min at the isocenter. Due to non-coplanar beam arrangement and dynamic dose shaping features, the GammaPod delivers uniform doses to the targets with excellent conformity. The spatial accuracy of the device is less than 1 mm. Single shot profiles with the 25 mm collimator are measured with radiochromic film and found to be in good agreement with respect to the MC based calculations (congruence of FWHM less than 1 mm). Dosimetric verifications corresponding to all treatment plans corresponding to three target scenarios for each of the eight patients demonstrated Gamma index pass rates greater than 97%. CONCLUSIONS: The first description of the dosimetric and geometric evaluation of the GammaPod was performed. The observed level of agreement between the treatment planning system calculations and dosimetric measurements has confirmed that the system can deliver highly complex treatment plans with remarkable geometric and dosimetric accuracy. C Yu and J Zhang have commercial affiliations with Xcision Medical Systems.

SU-D-BRB-04: FDG-PET Histogram Distances: Novel Predictors of Tumor Response to Chemoradiotherapy.

PURPOSE: To examine the accuracy of FGD-PET histogram distances as predictors of pathologic tumor response to chemo-radiotherapy (CRT) in esophageal cancer. METHODS: Twenty patients were included. A rigid registration was used to align the post-CRT PET/CT with the pre-CRT PET/CT images. The primary tumor was delineated using a region-growing algorithm with a threshold of SUV = 2.5 on the pre-CRT PET. Two histograms of SUVs within the tumor were constructed on the pre-CRT PET and registered post-CRT PET, respectively. The differences between the two histograms reflected changes in the SUV distribution and were therefore potential predictors of tumor response. The differences were quantitatively measured by histogram distances using 12 bin-to-bin and 8 cross-bin algorithms. The accuracy of histogram distances in predicting pathologic tumor response to CRT was measured using the area under ROC curve (AUC), prediction accuracy, and the Mann-Whitney tests, in comparison with traditional PET response measures and texture features. RESULTS: Cross-bin histogram distances were shown to be significant (p<0.05) predictors of pathologic tumor response. They were more accurate than bin- to-bin histogram distances (not significant). The most accurate cross-bin histogram distances were: Quadratic-Chi distance (AUC=0.89, accuracy=80%, p=0.003), Earth Mover distance (AUC=0.83,accuracy=80%, p=0.014), diffusion distance (AUC = 0.82, accuracy=85%, p=0.02) and Match distance (AUC = 0.79, accuracy=80%, p=0.03). This family of novel predictors were more accurate than traditional PET response measures using SUVmax (AUC=0.76, accuracy=75%, p=0.05), SUVpeak (AUC=0.74, accuracy=70%, p=0.08), Total Glycolytic Volume (AUC=0.76, accuracy=70%, p=0.05), as well as texture features based on the cooccurrence matrix (Inertia: AUC=0.85, accuracy=80%, p=0.01). CONCLUSIONS: The cross-bin histogram distances characterized changes in the SUV distribution within a tumor and showed high accuracy for the prediction of pathologic response to CRT in esophageal cancer. This workwas supported in part by the National Cancer Institute Grant R21 CA131979.

Small CGG repeat expansion alleles of FMR1 gene are associated with parkinsonism.

Fragile X-associated tremor/ataxia syndrome (FXTAS) affects older males carrying premutation, that is, expansions of the CGG repeat (in the 55-200 range), in the FMR1 gene. The neurological changes are linked to the excessive FMR1 messenger RNA (mRNA), becoming toxic through a 'gain-of-function'. Because elevated levels of this mRNA are also found in carriers of the smaller expansion (grey zone) alleles, ranging from 40 to 54 CGGs, we tested for a possible role of these alleles in the origin of movement disorders associated with tremor. We screened 228 Australian males affected with idiopathic Parkinson's disease and other causes of parkinsonism recruited from Victoria and Tasmania for premutation and grey zone alleles. The frequencies of either of these alleles were compared with the frequencies in a population-based sample of 578 Guthrie spots from consecutive Tasmanian male newborns (controls). There was a significant excess of premutation carriers (Fisher's exact test p = 0.006). There was also a more than twofold increase in grey zone carriers in the combined sample of the Victorian and Tasmanian cases, with odds ratio (OR ) = 2.36, and 95% confidence intervals (CI): 1.20-4.63, as well as in Tasmanian cases only (OR = 2.33, 95% CI: 1.06-5.13), compared with controls. The results suggest that the FMR1 grey zone alleles, as well as premutation alleles, might contribute to the aetiology of disorders associated with parkinsonism.

Origin and characterisation of microparticles in an ice core from the Central Dronning Maud Land, East Antarctica.

The scanning electron microscopy-energy dispersive spectroscopic (SEM-EDS) study of selected samples from an ice core collected from Central Dronning Maud Land (CDML), East Antarctica, revealed several microparticles. They are mainly siliceous and carbonaceous particles and have distinct variations in their shape and composition. The morphology and major element chemistry of the particles suggest their origin from either volcanic eruptions or continental dust. The EDS analysis revealed that the volcanic particles are enriched in silica (average SiO2 62%), compared to the continental dust particle (average SiO2 56%). We found that the tephra relating to Agung (1963) and Karkatau (1883) volcanic eruptions, as recorded, in the ice core harbored microbial cells (both coocoid and rods). The occurrence of organic and inorganic particles which bear relation to volcanic eruption and continental dust implies significant environmental changes in the recent past.

Reduction in asthma morbidity following a community-based asthma self-management programme in Tonga.

BACKGROUND: The Tonga Asthma Self-management Project assessed whether the introduction of an asthma self-management plan would reduce asthma morbidity. METHODS: The project involved a 'before and after' trial, with each participant serving as his/her own control. Asthma patients used the self-management plan to manage their asthma medication or obtain medical help based on their peak expiratory flow (PEF) rate and/or asthma symptoms. RESULTS: The 110 participants initially had relatively high asthma morbidity: 68% had had an emergency medical visit for asthma in the previous 12 months. Ninety-two (84%) completed the 12-month programme. Emergency doctor visits fell from 66% in the previous 12 months to 18% (P < 0.001) in the following 12 months. Other measures also improved, including hospital admissions (from 19% to 3%, P = 0.001), having 14 days or more 'out of action' (from 29% to 4%, P < 0.001), waking > or = 2 nights a week (from 40% to 13%, P < 0.001), severe asthma attacks (from 54% to 18%, P < 0.001) and mean PEF rates (from 341 l/min to 417 l/min, a 22% increase, P < 0.001). CONCLUSIONS: The potential benefits of asthma self-management plans and community-based asthma education are supported by the findings of the Tonga study. Their implementation is essential in the resource-scarce Pacific health setting.

Long-term assessment of oxcarbazepine in a naturalistic setting: a retrospective study.

BACKGROUND: New antiepileptics seem to be better tolerated by patients. The retention rate of an antiepileptic would be a useful indicator of its practical usefulness. AIMS: To assess the long-term outcome of oxcarbazepine (OXC) in a naturalistic setting by determining the retention rate. METHODS: This is a retrospective study. All epilepsy patients treated with OXC at a tertiary care epilepsy center during a period of 3.5 years were included in this study. Retention rates of OXC at 1 and 3 years were estimated for each cohort group using Kaplan-Meier estimates and corresponding 95% confidence intervals. RESULTS: A total of 98 patients were studied. OXC was used as monotherapy in 14 (14.3%) and as add-on therapy in 84 (85.7%). The mean daily dose was 947 +/- 492 mg and 60% received < or = 900 mg/day. Using the Kaplan-Meier survival analysis, the retention rates of OXC at 1 and 3 years were estimated to be 0.853 (0.749-0.956) and 0.737 (0.570-0.904), respectively. CONCLUSIONS: OXC is well tolerated by patients as both monotherapy and add-on therapy.