Human Head Modelling Simulation Applied to Electroconvulsive Therapy

Transcranial electrical stimulation includes electrical stimulation techniques used to treat neurological conditions. Computational human head modelling has been used to investigate diverse cases of therapies and treatments. In this chapter, 3D realistic human head models constructed from magnetic resonance images are presented for applications in electroconvulsive therapy (ECT). This technique uses low frequency and applies high amplitude current for a short period. Due to the high currents used in ECT, electrical stimulation may generate heat as per the Joule effect. Therefore, the bio-heat transfer equation coupled to the Laplace equation is implemented in a computational head model to investigate the effect of temperature due to ECT electrical stimulation. Diverse thermophysical parameters and electrode configurations are considered. The results show that, from the thermal point of view, the brain is safe and no increase in temperature is detected. Temperature rises mainly in external layers of head, such as scalp and skull while the inclusion of fat layer will influence temperature behavior. Apart from that, the inclusion of thermal anisotropic conductivity does not significantly influence temperature rise; however, electrical conductivity is an important factor to consider

Do drug treatment variables predict cognitive performance in multidrug-treated opioid-dependent patients? A regression analysis study

<p>Abstract</p> <p>Background</p> <p>Cognitive deficits and multiple psychoactive drug regimens are both common in patients treated for opioid-dependence. Therefore, we examined whether the cognitive performance of patients in opioid-substitution treatment (OST) is associated with their drug treatment variables.</p> <p>Methods</p> <p>Opioid-dependent patients (N = 104) who were treated either with buprenorphine or methadone (n = 52 in both groups) were given attention, working memory, verbal, and visual memory tests after they had been a minimum of six months in treatment. Group-wise results were analysed by analysis of variance. Predictors of cognitive performance were examined by hierarchical regression analysis.</p> <p>Results</p> <p>Buprenorphine-treated patients performed statistically significantly better in a simple reaction time test than methadone-treated ones. No other significant differences between groups in cognitive performance were found. In each OST drug group, approximately 10% of the attention performance could be predicted by drug treatment variables. Use of benzodiazepine medication predicted about 10% of performance variance in working memory. Treatment with more than one other psychoactive drug (than opioid or BZD) and frequent substance abuse during the past month predicted about 20% of verbal memory performance.</p> <p>Conclusions</p> <p>Although this study does not prove a causal relationship between multiple prescription drug use and poor cognitive functioning, the results are relevant for psychosocial recovery, vocational rehabilitation, and psychological treatment of OST patients. Especially for patients with BZD treatment, other treatment options should be actively sought.</p

Photodynamic therapy of subfoveal choroidal neovascularization in pathologic myopia with verteporfin - 1-year results of a randomized clinical trial - VIP report no. 1

Objective: To determine if photodynamic therapy with verteporfin (Visudyne; CIBA Vision Corp, Duluth, GA) can improve the chance of stabilizing or improving vision (m and best-corrected visual acuity (Snellen equivalent) of approximately 20/100 or better. Intervention: Patients were randomly assigned (2:1) to verteporfin (6 mg per square meter of body surface area; n = 81) or placebo (5% dextrose in water, n = 39) administered via intravenous infusion of 30 ml over 10 minutes. Fifteen minutes after the start of the infusion, a laser light at 689 nm was delivered at an intensity of 600 mW/cm(2) over 83 seconds to give a light dose of 50 J/cm(2) to a round spot size on the retina with a diameter of 1000 mum larger than the greatest linear dimension of the choroidal neovascular lesion. At follow-up examinations every 3 months, retreatment with either verteporfin or placebo (as assigned at baseline) was applied to areas of fluorescein leakage if present. Main Outcome Measures: The primary outcome was the proportion of eyes at the follow-up examination 12 months after study entry with fewer than eight letters (approximately 1.5 lines) of visual acuity lost, adhering to an intent-to-treat analysis. Results: At baseline, move than 90% of each group had evidence of classic CNV (regardless of whether occult CNV was present) and only 12 (15%) and 5 (13%) cases in the verteporfin and placebo groups, respectively, had occult CNV (regardless of whether classic CNV was present). Seventy-nine of the 81 verteporfin-treated patients (98%) compared with 36 of the 39 placebo-treated patients (92%) completed the month 12 examination. Visual acuity, contrast sensitivity, and fluorescein angiographic outcomes were better in the verteporfin-treated eyes than in the placebo-treated eyes at every follow-up examination through the month 12 examination. At the month 12 examination, 58 (72%) of the verteporfin-treated patients compared with 17 (44%) of the placebo-treated patients lost fewer than eight letters (P 1 line). Seventy (86%) of the verteporfin-treated patients compared with 26 (67%) of the placebo-treated patients lost fewer than 15 letters (P = 0.01), Few ocular or other systemic adverse events were associated with verteporfin therapy compared with placebo treatment. Conclusions: Because photodynamic therapy with verteporfin can safely increase the chance of stabilizing or improving vision in patients with subfoveal CNV from pathologic myopia compared with a placebo, we recommend ophthalmologists consider verteporfin therapy for treatment of such patients. Ophthalmology 2001; 108:841-852 (C) 2001 by the American Academy of Ophthalmology