Psychotic experiences have been proposed to lie on a spectrum, ranging from subclinical experiences to treatment-resistant schizophrenia. We aimed to characterize functional connectivity and brain network characteristics in relation to the schizophrenia spectrum and bipolar disorder with psychosis to disentangle neural correlates to psychosis. Additionally, we studied antipsychotic medication and lithium effects on network characteristics. We analyzed functional connectivity strength and network topology in 487 resting-state functional MRI scans of individuals with schizophrenia spectrum disorder (SCZ), bipolar disorder with a history of psychotic experiences (BD), treatment-naïve subclinical psychosis (SCP), and healthy controls (HC). Since differences in connectivity strength may confound group comparisons of brain network topology, we analyzed characteristics of the minimum spanning tree (MST), a relatively unbiased backbone of the network. SCZ and SCP subjects had a lower connectivity strength than BD and HC individuals but showed no differences in network topology. In contrast, BD patients showed a less integrated network topology but no disturbances in connectivity strength. No differences in outcome measures were found between SCP and SCZ, or between BD patients that used antipsychotic medication or lithium and those that did not. We conclude that functional networks in patients prone to psychosis have different signatures for chronic SCZ patients and SCP compared to euthymic BD patients, with a limited role for medication. Connectivity strength effects may have confounded previous studies, as no functional network alterations were found in SCZ after strict correction for connectivity strength.
A growing body of literature suggests the important role of the thalamus in cognition and neurodegenerative diseases. This study aims to elucidate whether the preoperative thalamic volume is associated with preoperative cognitive impairment (preCI) and whether it is predictive for postoperative cognitive dysfunction at 3 months (POCD). We enrolled 301 patients aged 65 or older and without signs of dementia who were undergoing elective surgery. Magnetic resonance imaging was conducted prior to surgery. Freesurfer (version 5.3.) was used to automatically segment the thalamus volume. A neuropsychological test battery was administered before surgery and at a 3 month follow-up. It included the computerized tests Paired Associate Learning (PAL), Verbal Recognition Memory (VRM), Spatial Span Length (SSP), Simple Reaction Time (SRT), the pen-and-paper Trail-Making-Test (TMT) and the manual Grooved Pegboard Test (GPT). Using a reliable change index, preCI and POCD were defined as total Z-score > 1.96 (sum score over all tests) and/or Z-scores > 1.96 in ≥ 2 individual cognitive test parameters. For statistical analyses, multivariable logistic regression models were applied. Age, sex and intracranial volume were covariates in the models. Of 301 patients who received a presurgical neuropsychological testing and MRI, 34 (11.3%) had preCI. 89 patients (29.5%) were lost to follow-up. The remaining 212 patients received a follow-up cognitive test after 3 months, of whom 25 (8.3%) presented with POCD. Independently of age, sex and intracranial volume, neither preCI (OR per cm3 increment 0.81 [95% CI 0.60–1.07] p = 0.14) nor POCD (OR 1.02 per cm3 increment [95% CI 0.75–1.40] p = 0.87) were statistically significantly associated with patients’ preoperative thalamus volume. In this cohort we could not show an association of presurgical thalamus volume with preCI or POCD.Clinical Trial Number: NCT02265263 (https://clinicaltrials.gov/ct2/show/results/NCT02265263).
IntroductionIn 2012, the Netherlands introduced a conditional reimbursement (CR) program to give patients earlier access to promising treatments (i.e., drugs and medical devices). After completion of the CR-study the results are used to (re)assess whether the treatment fulfills the criteria for reimbursement.MethodsPromising treatments were identified via a bottom-up (physicians/researchers initiated) or top-down process (after the Dutch National Health Care Institute (Zorginstituut Netherland; ZIN) concluded that the intervention did not fulfill the criteria for reimbursement but the initial results seemed promising). A CR-grant was only approved if a committee determined the treatment had an added (health, social, ethical or organizational) benefit compared to Standard of Care (SoC) and the grant proposal was of good quality and fit for purpose. After approval from the Dutch Ministry of Health, all Dutch insurance companies were obliged to reimburse the treatment for patients participating in the CR-study. Researchers could also apply for a research grant (maximum EUR 400,000) from the Netherlands Organization for Health Research and Development (ZonMw), if there was no ‘wealthy’ manufacturer.ResultsCurrently, there are 23 (ongoing and completed) CR-studies. All of them are closely monitored by ZIN, ZonMw, and stakeholders. The results of all completed CR-studies (n = 11) have been used in a (re)assessment. ZIN concluded that five treatments were not effective compared to SoC. Six interventions were effective and cost-effective compared to SoC and are now reimbursed. In most cases (>80%) the physician and patient groups agreed with the conclusion about reimbursement. In some cases there were additional requirements to maintain the clinical effectiveness and cost-effectiveness in clinical practice (such as training of new physicians).ConclusionsData from CR-studies are important for reassessments. Factors with a positive influence are: a maximum duration for a CR-study, close monitoring, possibility to adapt the study design (only with approval from ZIN and ZonMw), and active involvement of stakeholders (physician and patient groups). A negative influence was: the legal requirements to ensure only reimbursement for patients participating in a CR-study.
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