Dopaminergic neurotransmission in psychiatry: should selection of patients only be based on DSM or ICD criteria?
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Biomedical subjects
Publications and source records attributed to I Goethals.
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Reliable and high-resolution reference data for regional cerebral blood flow measured with single-photon emission tomography (SPET) are necessary for optimal clinical and research use. Therefore, a large dataset of normal technetium-99m labelled ethylene cysteine dimer (ECD) perfusion SPET in carefully screened healthy volunteers with an age range spanning six decades was created, with correction for non-uniform attenuation and scatter and based on an anatomically standardised analysis. Eighty-nine healthy volunteers, stratified for gender (46 females, 43 males; age 20-81 years), were included. Twelve volunteers underwent repeated 99mTc-ECD SPET after 2.5+/-2.3 weeks. An automated whole-brain volume of interest analysis with MANOVA as well as voxelwise analysis using SPM99 was conducted. Average intersubject variability was 4.8% while intrasubject reproducibility was 3.0%. An age-related decline in tracer uptake was found in the anterior cingulate gyrus, bilateral basal ganglia, left prefrontal, left lateral frontal and left superior temporal and insular cortex (all P=0.001-0.02). There was an overall increase in right/left asymmetry with age, which was most pronounced in the frontal and temporal neocortex. The most significant correlations between AI and age decade were found in the prefrontal (R=0.35, P=0.001) and superior temporal neocortex (R=0.43, P<0.001). Women had significantly higher uptake in the right parietal cortex (P<0.001), while men showed higher uptake in the cerebellum and the left anterior temporal and orbitofrontal cortex (all P<0.01). This normative dataset allows age- and gender-specific patient and group assessment of 99mTc-ECD perfusion SPET under a wide variety of clinical circumstances in relation to normal variations and highlights the importance of both age- and gender-specific normal datasets for optimal analysis sensitivity.
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This study investigated the feasibility of brain single photon emission computed tomography (SPECT) functional imaging in a neuropsychological test setting, following a single-day protocol with a split-dose paradigm. The Stroop Color Word Test (SCWT) is an example of a well-documented prefrontal activation task. In a split-dose protocol, ten right-handed healthy volunteers were injected twice with 370 MBq 99Tcm-ethyl cysteinate dimer while performing consecutively both series of card-reading of the SCWT. Images were reconstructed using filtered back-projection and normalized to a standard template in Talairach coordinates. Statistical Parametric Mapping (SPM96) was used to determine voxelwise significant changes. A first activation cluster was found in the left medial prefrontal cortex, consisting of the gyrus cinguli anterior and the gyrus frontalis medius and superior. A second activation cluster included the right gyrus frontalis dorsalis and medius. These findings confirm to a large extent the results of previous functional magnetic resonance imaging, positron emission tomography studies of Stroop-like tasks. The choice and validity of various methodological characteristics of the experimental design leading to these results is critically discussed. It is concluded that brain SPECT activation with the Stroop Color Word Test under standard neuropsychological conditions in healthy volunteers, is both technically and practically feasible.
The purpose of these guidelines is to assist nuclear medicine practitioners in recommending, performing, interpreting, and reporting the results of brain perfusion SPECT studies using Tc-99m radiopharmaceuticals and brain metabolism PET studies using F-18 fluorodeoxyglucose (FDG). These guidelines have been adapted and extended from those produced by the Society of Nuclear Medicine (Juni et al., 1998) and the European Association of Nuclear Medicine by a Belgian group of experts in the field trained in neurology and/or nuclear medicine. Some indications are not universally approved (e.g. brain death), but largely supported by the literature. They have been included in these guidelines in order to provide recommendations and a standardised protocol.
INTRODUCTION: Vagus nerve stimulation is a novel treatment for patients with medically refractory epilepsy, who are not candidates for conventional epilepsy surgery, or who have had such surgery without optimal outcome. To date only studies with relatively short follow-up are available. In these studies efficacy increased with time and reached a maximum after a period of 6 to 12 months. Implantation of a vagus nerve stimulator requires an important financial investment but a cost-benefit analysis has not been published. PATIENTS AND METHODS: Our own experience with VNS in Gent comprises 15 patients with mean age of 29 years (range: 17-44 years) and mean duration of epilepsy of 18 years (range: 4-32 years). All patients underwent a comprehensive presurgical evaluation and were found not to be suitable candidates for resective epilepsy surgery. Mean post-implantation follow-up is 24 months (range: 7-43 months). In patients with follow-up of at least one year, efficacy of treatment in terms of seizure control and seizure severity was assessed one year before and after the implantation of a vagus nerve stimulator. Epilepsy-related direct medical costs (ERDMC) before and after the implantation were also compared. RESULTS: A mean reduction of seizure frequency from 14 seizures/month (range: 2-40/month) to 8 seizures/month (range: 0-30/month) was achieved (Wilcoxon signed rank test n = 14; p = 0.0016). Five patients showed a marked seizure reduction of > or = 50%; 6 became free of complex partial seizures, 3 of whom became entirely seizure free for more than 12 months; 2 patients had a worthwhile reduction of seizure frequency between 30-50%; in 2 patients seizure frequency reduction has remained practically unchanged. Seizure freedom or > or = 50% seizure reduction was achieved within the first 4 months after implantation in 6/11 patients. Before the implantation, the mean yearly epilepsy-related direct medical costs per patient were estimated to be 8830 US$ (n = 13; range: 1879-31,129 US$; sd = 7667); the average number of hospital admission days per year was 21 (range: 4-100; sd = 25.7). In the 12 months after implantation, ERDMC had decreased to 4215 US$ (range: 615-11,794 US$; sd = 3558) (Wilcoxon signed rank test n = 13; p = 0.018) and the average number of admission days to 8 (range: 0-35) (Wilcoxon signed rank test n = 13; p = 0.023). CONCLUSION: VNS is an effective treatment of refractory epilepsy and remains effective during long-term follow-up. Cost-benefit analysis suggests that the cost of VNS is saved within two years following implantation.
PURPOSE: The purpose of this paper is to demonstrate the diagnostic efficacy and therapeutic relevance of video-EEG monitoring in an large patient population with long-term follow-up. PATIENTS AND METHODS: Between October 1990 and May 1997, 400 patients were monitored at the Epilepsy Monitoring Unit (EMU) of the University Hospital in Gent. In all patients, the following parameters were retrospectively examined: reason for referral, tentative diagnosis, prescribed antiepileptic drugs (AEDs), seizure frequency, number of admission days, number of recorded seizures, ictal and interictal EEG, clinical and electroencephalographic diagnosis following the monitoring session. During follow-up visits at the Epilepsy Clinic, we prospectively collected data on different types of treatment and post-monitoring seizure control. RESULTS: 255/400 (64%) patients were referred for refractory epilepsy. 145/400 (36%) patients were evaluated for attacks of uncertain origin. Mean follow-up, available in 225 patients, was 28 months (range: 6-80 months). Mean duration of a single monitoring session was 4 days (range: 2-7 days). Prolonged interictal EEG was recorded in all patients and ictal EEG in 258 (65%) patients. Following the monitoring session, the diagnosis of epilepsy was confirmed in 217 patients. Pseudoseizures were diagnosed in 31 patients (8%). AEDs were started in 19 patients, stopped in 6 and left unchanged in 110. The type and/or number of AEDs was changed in 111 patients. Sixty patients underwent epilepsy surgery. In 48 surgery patients, follow-up data were available, 29 of whom became seizure-free, and 16 of whom experienced a greater than 90% seizure reduction. Vagus nerve stimulation was performed in 11 patients, 2 became seizure-free, and 7 improved markedly. Of the non-invasively treated patients in whom follow-up was available (n = 135), 70 became seizure-free or experienced a greater than 50% reduction in seizure frequency; 51 patients experienced no change in seizure frequency. Outcome was unrelated to the availability of ictal video-EEG recording. In patients with complex partial seizures, seizure control was significantly improved when a well-defined ictal onset zone could be defined during video-EEG monitoring. CONCLUSION: Prolonged interictal EEG monitoring is mandatory in the successful management of patients with refractory epilepsy. Ictal video-EEG monitoring is very helpful but not indispensable, except in patients enrolled for presurgical evaluation or suspected of having pseudoseizures.
To assess whether procedures of semen preparation can reduce the proportion of antibody-coated spermatozoa, semen samples with positive direct mixed antiglobulin reaction (MAR) were washed in media supplemented with 10% or 50% fetal cord serum (FCS). Washing reduced the MAR to a negative level, but the MAR was identical to that in the native semen when spermatozoa were resuspended in serum-free medium. Donor spermatozoa, recovered after swim-up in media supplemented with 10% or 50% FCS or after passage through a column with 7.5% human serum albumin (HSA), were incubated in serum samples with both agglutinating and cytotoxic antisperm antibodies. Cytotoxic activity was significantly reduced against sperm filtered over the albumin column.
The direct Mixed Antiglobulin Reaction (MAR test) is a simple method for the detection of auto-antibodies attached to spermatozoa in fresh semen. The test was improved by using IgG-coated latex particles (SpermMAR) instead of coated red blood cells. A positive direct MAR test with adherence of latex particles to 40% or more of the motile spermatozoa was found in 16 out of 312 men (5%) consulting for infertility, but never in fertile controls. The percentage of motile spermatozoa reacting with the coated latex particles was correlated significantly with the serum titre of sperm agglutinins assessed by the tray agglutination test. The direct MAR test on semen was highly specific but rather insensitive, particularly if the serum titre of agglutinins was low. The same kit (SpermMAR) can be used to detect circulating sperm antibodies in serum of male or female patients with the indirect mixed antiglobulin reaction. The indirect MAR test discriminated clearly between serum with low (less than 1/32) or high (greater than 1/32) titres of circulating agglutinins assessed by the tray agglutination test. Considering their simplicity and accuracy, both the direct test on semen and the indirect spermMAR test on serum should be included in the routine evaluation of the infertile couple.