Cannabis for the treatment of amyotrophic lateral sclerosis: What is the patients' view?

Cannabis may have therapeutic benefits to relieve symptoms of amyotrophic lateral sclerosis (ALS) thanks to its pleiotropic pharmacological activity. This study is the first to present a large questionnaire-based survey about the "real-life" situation regarding cannabis use in the medical context in ALS patients in France. There were 129 respondents and 28 reported the use of cannabis (21.7%) to relieve symptoms of ALS. Participants mostly reported the use of cannabidiol (CBD) oil and cannabis weed and declared benefits both on motor (rigidity, cramps, fasciculations) and non-motor (sleep quality, pain, emotional state, quality of life, depression) symptoms and only eight reported minor adverse reactions (drowsiness, euphoria and dry mouth). Even if cannabis is mostly used outside medical pathways and could expose patients to complications (street and uncontrolled drugs, drug-drug interactions, adverse effects…), most of the participants reported "rational" consumption (legal cannabinoids, with only few combustion and adverse reactions). Despite some limitations, this study highlights the need for further research on the potential benefits of cannabis use for the management of ALS motor and non-motor symptoms. Indeed, there is an urgent need and call for and from patients to know more about cannabis and secure its use in a medical context.

Multivariate GWAS of Alzheimer's disease CSF biomarker profiles implies GRIN2D in synaptic functioning

BACKGROUND

Genome-wide association studies (GWAS) of Alzheimer's disease (AD) have identified several risk loci, but many remain unknown. Cerebrospinal fluid (CSF) biomarkers may aid in gene discovery and we previously demonstrated that six CSF biomarkers (β-amyloid, total/phosphorylated tau, NfL, YKL-40, and neurogranin) cluster into five principal components (PC), each representing statistically independent biological processes. Here, we aimed to (1) identify common genetic variants associated with these CSF profiles, (2) assess the role of associated variants in AD pathophysiology, and (3) explore potential sex differences.

METHODS

We performed GWAS for each of the five biomarker PCs in two multi-center studies (EMIF-AD and ADNI). In total, 973 participants (n = 205 controls, n = 546 mild cognitive impairment, n = 222 AD) were analyzed for 7,433,949 common SNPs and 19,511 protein-coding genes. Structural equation models tested whether biomarker PCs mediate genetic risk effects on AD, and stratified and interaction models probed for sex-specific effects.

RESULTS

Five loci showed genome-wide significant association with CSF profiles, two were novel (rs145791381 [inflammation] and GRIN2D [synaptic functioning]) and three were previously described (APOE, TMEM106B, and CHI3L1). Follow-up analyses of the two novel signals in independent datasets only supported the GRIN2D locus, which contains several functionally interesting candidate genes. Mediation tests indicated that variants in APOE are associated with AD status via processes related to amyloid and tau pathology, while markers in TMEM106B and CHI3L1 are associated with AD only via neuronal injury/inflammation. Additionally, seven loci showed sex-specific associations with AD biomarkers.

CONCLUSIONS

These results suggest that pathway and sex-specific analyses can improve our understanding of AD genetics and may contribute to precision medicine.

Rare variants in IFFO1, DTNB, NLRC3 and SLC22A10 associate with Alzheimer's disease CSF profile of neuronal injury and inflammation

Alzheimer's disease (AD) biomarkers represent several neurodegenerative processes, such as synaptic dysfunction, neuronal inflammation and injury, as well as amyloid pathology. We performed an exome-wide rare variant analysis of six AD biomarkers (β-amyloid, total/phosphorylated tau, NfL, YKL-40, and Neurogranin) to discover genes associated with these markers. Genetic and biomarker information was available for 480 participants from two studies: EMIF-AD and ADNI. We applied a principal component (PC) analysis to derive biomarkers combinations, which represent statistically independent biological processes. We then tested whether rare variants in 9576 protein-coding genes associate with these PCs using a Meta-SKAT test. We also tested whether the PCs are intermediary to gene effects on AD symptoms with a SMUT test. One PC loaded on NfL and YKL-40, indicators of neuronal injury and inflammation. Four genes were associated with this PC: IFFO1, DTNB, NLRC3, and SLC22A10. Mediation tests suggest, that these genes also affect dementia symptoms via inflammation/injury. We also observed an association between a PC loading on Neurogranin, a marker for synaptic functioning, with GABBR2 and CASZ1, but no mediation effects. The results suggest that rare variants in IFFO1, DTNB, NLRC3, and SLC22A10 heighten susceptibility to neuronal injury and inflammation, potentially by altering cytoskeleton structure and immune activity disinhibition, resulting in an elevated dementia risk. GABBR2 and CASZ1 were associated with synaptic functioning, but mediation analyses suggest that the effect of these two genes on synaptic functioning is not consequential for AD development.

Functional connectivity and cognitive changes after donepezil treatment in healthy participants

RATIONALE

Donepezil is a potent, noncompetitive, reversible, clinically effective acetylcholinesterase inhibitor. The effects of this drug on healthy brains have seldom been investigated.

OBJECTIVES

The primary objective of the present study was to identify possible functional connectivity markers of the effect of donepezil in healthy young adult volunteers.

METHODS

The study had a double-blind, randomized, crossover design. 30 healthy adult volunteers underwent resting-state MRI scans during 15 days of donepezil or placebo treatment, in accordance with the design.

RESULTS

Results showed significant differences in intrinsic functional connectivity between donepezil and placebo, mainly in the right executive control network (RECN). More specifically, we found a decrease in the connectivity of the right inferior parietal node with other RECN nodes. Analysis using the cingulate cortex and parahippocampal regions as seeds also revealed complex modulation of functional connectivity in the donepezil condition.

CONCLUSIONS

In conclusion, donepezil treatment for 15 days may result in reorganization of resting-state networks, compared with placebo.

Aminoglycosides in critically ill patients: which dosing regimens for which pathogens?

Modifications of antibiotic pharmacokinetic parameters have been reported in critically ill patients, resulting in a risk of treatment failure. We aimed to determine optimised amikacin (AMK), gentamicin (GEN) and tobramycin (TOB) intravenous dosing regimens in this patient population. Patients admitted to the medical ICU and treated with AMK, GEN or TOB were included. Analyses were performed using a parametric population approach. Monte Carlo simulations were performed and the probability of target attainment (PTA) was calculated using C_max/MIC ≥ 8 and trough concentrations as targets. A total of 117 critically ill hospitalised patients were studied. Median values (interindividual variability, ɷ²) of clearance were 3.51 (0.539), 3.53 (0.297), 2.70 (0.339) and 5.07 (0.339) L/h for AMK, GEN, TOB, and TOB in cystic fibrosis (CF), respectively. Median values (ɷ²) of central volume of distribution were 30.2 (0.215), 20.0 (0.109) and 25.6 (0.177) L for AMK, GEN and TOB, respectively. Simulations showed that doses should be adjusted to actual body weight and creatinine clearance (CLCR) for AMK and GEN, and according to CLCR and presence of CF for TOB. In conclusion, our recommendations for treating Pseudomonas aeruginosa infections in this population include using initial doses of 35 mg/kg for AMK or 10 mg/kg for TOB (CF and non-CF patients). GEN demonstrated the best rates of target attainment against Staphylococcus aureus infections with a dose of 5 mg/kg. As high aminoglycoside doses are required in this population, efficacy and safety targets are conflicting and therapeutic drug monitoring remains an important tool to manage this issue.

External evaluation of population pharmacokinetic models for continuous administration of meropenem in critically ill adult patients

PURPOSE

Beta-lactams (BL), the most commonly prescribed class of antibiotics, are recommended as the first-line therapy for multiple indications in infectious disease guidelines. Meropenem (MERO) is frequently used in intensive care units (ICU) to treat bacterial infections with or without sepsis. The pharmacokinetics of MERO display a large variability in patients admitted to ICUs due to altered pathophysiology. The aim of this study was to perform an external evaluation of published population pharmacokinetic models of MERO in order to test their predictive performance in a cohort of ICU adult patients.

METHODS

A literature search in PubMed/Medline database was made following the PRISMA statement. External evaluation was performed using NONMEM software, and the bias and inaccuracy values were calculated.

RESULTS

An external validation dataset from the Timone Hospital in Marseille, France, included 84 concentration samples from 27 patients. Four models of MERO were identified according to the inclusion criteria of the study. None of the models presented acceptable values of bias and inaccuracy.

CONCLUSION

While performing external evaluations on some populations may confirm a model's suitability to diverse groups of patients, there is still some variability that cannot be explained nor solved by the procedure. This brings to light the difficulty to develop only one model for ICU patients and the need to develop one specific model to each population of critically ill patients.

miR-146a and miR-181a are involved in the progression of mild cognitive impairment to Alzheimer's disease

The identification of mechanisms associated with Alzheimer's disease (AD) development in mild cognitive impairment (MCI) would be of great usefulness to clarify AD pathogenesis and to develop preventive and therapeutic strategies. In this study, blood levels of the candidate microRNAs (small noncoding RNAs that play a pivotal role in gene expression) miR-146a, miR-181a, miR-181b, miR-24-3p, miR-186a, miR-101, miR-339, miR-590, and miR-22 have been investigated for association to AD conversion within 2 years in a group of 45 patients with MCI. Baseline miR-146a (p = 0.036) and miR-181a (p = 0.026) showed a significant upregulation in patients with MCI who later converted to AD. These alterations were related to AD hallmarks: a significant negative correlation was found with amyloid beta cerebrospinal fluid concentration for miR-146a (p = 0.006) and miR-181a (p = 0.001). Moreover, higher levels of miR-146a were associated to apolipoprotein E ε4 allele presence, smaller volume of the hippocampus (p = 0.045) and of the CA1 (p = 0.013) and the subiculum (p = 0.027) subfields. Increased levels of miR-146a (p = 0.031) and miR-181a (p = 0.002) were also linked with diffusivity alterations in the cingulum. These data support a role for miR-146a and miR-181a in the mechanisms of AD progression.

Quantitative System Pharmacology (QSP): An Integrative Framework for paradigm change in the treatment of the first-episode schizophrenia

Despite the lack of progress in the curative treatment of mental illness, especially schizophrenia, the accumulation of neuroscience data over the past decade suggests the re-conceptualization of schizophrenia. With the advent of new biomarkers and cognitive tools, new neuroscience technologies such as functional dynamic connectivity and the identification of subtle clinical features; it is now possible to detect early stages at risk or prodromes of a first psychotic episode. Current concepts reconceptualizes schizophrenia as a neurodevelopmental disorder at early onset, with polygenic risk and only symptomatic treatment for positive symptoms at this time. The use of such technologies in the future suggests new diagnostic and therapeutic options. Next steps include new pharmacological perspectives and potential contributions of new technologies such as quantitative system pharmacology brain computational modeling approach.

Vancomycin in Pediatric Patients with Solid or Hematological Malignant Disease: Predictive Performance of a Population Pharmacokinetic Model and New Optimized Dosing Regimens

BACKGROUND

The application of population pharmacokinetic models and Bayesian methods offers the potential to develop individualized therapeutic approaches.

OBJECTIVES

The current study presents an external evaluation of a vancomycin pharmacokinetic model in a pediatric cancer population and proposes an easy-to-use chart for clinicians for a priori vancomycin schedule adaptation to achieve target concentration.

METHODS

External evaluation of a population pharmacokinetic model of vancomycin administered via continuous infusion was realized in a new retrospective dataset of pediatric patients with cancer. The published population pharmacokinetic model was implemented in NONMEM 7.3 with the structural and variance parameter values set equal to estimates previously reported. Predictive performance was assessed by quantifying bias and accuracy of model prediction. Normalized prediction distribution errors were also evaluated. Dosage simulations were performed according to the target concentration.

RESULTS

A total of 77 patients were included in this study, representing 146 vancomycin courses and 289 concentrations. The model adequately predicted vancomycin concentrations (median prediction error % of - 9.4%, median |PE|% of 24.1%). Based on simulation results, vancomycin dosage (mg/kg) should be adapted for each child on the basis of body weight and cyclosporine coadministration.

CONCLUSION

The model previously proposed by Guilhaumou et al. in pediatric patients with solid or hematological malignant disease was externally validated. Simulations have enabled the description of new dosage schedules and creation of a chart to help clinicians adapt vancomycin dosage.

Informativeness of patient initial reports of adverse drug reactions. Can it be improved by a pharmacovigilance centre?

PURPOSE

Little is known about the informativeness of initial patient reports before they are reviewed by a pharmacovigilance centre (PVC). We aim to describe the patterns of patient adverse drug reaction (ADR) reporting in France and estimate the contribution of a review by a PVC assessor on the informativeness of these reports.

METHODS

A retrospective study was conducted on patient reports between July 2011 and July 2015. Informativeness of 16 key elements of information (including drug start and end date, duration of treatment, time to onset and duration of the ADR, outcome, medical history and concomitant medication) was assessed in initial reports before and after review by a pharmacovigilance assessor.

RESULTS

Overall, 240 reports concerning 522 ADR and involving 278 drugs were reported over this 4-year period. Mean number of available key elements of information in initial reports was increased from 11/16 to 15/16 after review of reports by the PVC. Time to onset and duration of the ADR were respectively available in only 51 and 58% of the reports before review compared to 83 and 90% after review. Medical history and concomitant medication were missing in 75% of the initial reports compared to less than 30% of the reports after review. Contacting the reporter enabled an increase of informativeness of most elements of information for more than 90% of the reports.

CONCLUSION

Patient reports often need to be completed on key elements of information that are required to assess reports. Both upstream education of patients and downstream intervention of a pharmacovigilance assessor to complete missing information could help to enhance the informativeness of such reports.

[Evaluating the efficacy of long acting injectable antipsychotics through clinical trials]

After reminding the various phases of the development of molecules, this article will state the stages of commercialisation of treatments, underlining the FDA (Food and Drug Administration) and the EMA (European Medicine Agency) requirements. Like all the other treatments available in Europe and in the United States, the long acting injectable antipsychotics (LAI) have to prove their efficacy compared to placebo and their non-inferiority compared to a treatment of reference, usually the same molecule in the oral form. These criteria of efficacy have evolved over time. If initially classical criteria of symptomatic intensity (score on scale PANSS) were considered, criteria more adequate from a clinical perspective, such as relapse, but also related to functioning, quality of life and, more recently, costs-effectiveness have appeared. This evolution is probably due to several factors: vision on mental illness, progress in patient's rights and aspirations, but also the pregnant place of health costs recently taken in the evaluation of treatments. These modifications are also based on the indications of L.A.I., i.e. stabilized patients for whom the challenge is rehabilitation care more than the control of symptoms.

[What can we expect from clinical trials in psychiatry?]

Clinical trials in psychiatry allow to build the regulatory dossiers for market authorization but also to document the mechanism of action of new drugs, to build pharmacodynamics models, evaluate the treatment effects, propose prognosis, efficacy or tolerability biomarkers and altogether to assess the impact of drugs for patient, caregiver and society. However, clinical trials have shown some limitations. Number of recent dossiers failed to convince the regulators. The clinical and biological heterogeneity of psychiatric disorders, the pharmacokinetic and pharmacodynamics properties of the compounds, the lack of translatable biomarkers possibly explain these difficulties. Several breakthrough options are now available: quantitative system pharmacology analysis of drug effects variability, pharmacometry and pharmacoepidemiology, Big Data analysis, brain modelling. In addition to more classical approaches, these opportunities lead to a paradigm change for clinical trials in psychiatry.

Free water elimination improves test-retest reproducibility of diffusion tensor imaging indices in the brain: A longitudinal multisite study of healthy elderly subjects

Free water elimination (FWE) in brain diffusion MRI has been shown to improve tissue specificity in human white matter characterization both in health and in disease. Relative to the classical diffusion tensor imaging (DTI) model, FWE is also expected to increase sensitivity to microstructural changes in longitudinal studies. However, it is not clear if these two models differ in their test-retest reproducibility. This study compares a bi-tensor model for FWE with DTI by extending a previous longitudinal-reproducibility 3T multisite study (10 sites, 7 different scanner models) of 50 healthy elderly participants (55-80 years old) scanned in two sessions at least 1 week apart. We computed the reproducibility of commonly used DTI metrics (FA: fractional anisotropy, MD: mean diffusivity, RD: radial diffusivity, and AXD: axial diffusivity), derived either using a DTI model or a FWE model. The DTI metrics were evaluated over 48 white-matter regions of the JHU-ICBM-DTI-81 white-matter labels atlas, and reproducibility errors were assessed. We found that relative to the DTI model, FWE significantly reduced reproducibility errors in most areas tested. In particular, for the FA and MD metrics, there was an average reduction of approximately 1% in the reproducibility error. The reproducibility scores did not significantly differ across sites. This study shows that FWE improves sensitivity and is thus promising for clinical applications, with the potential to identify more subtle changes. The increased reproducibility allows for smaller sample size or shorter trials in studies evaluating biomarkers of disease progression or treatment effects. Hum Brain Mapp 38:12-26, 2017. © 2016 Wiley Periodicals, Inc.

Clinical and biomarker profiling of prodromal Alzheimer's disease in workpackage 5 of the Innovative Medicines Initiative PharmaCog project: a 'European ADNI study'

BACKGROUND

In the field of Alzheimer's disease (AD), the validation of biomarkers for early AD diagnosis and for use as a surrogate outcome in AD clinical trials is of considerable research interest.

OBJECTIVE

To characterize the clinical profile and genetic, neuroimaging and neurophysiological biomarkers of prodromal AD in amnestic mild cognitive impairment (aMCI) patients enrolled in the IMI WP5 PharmaCog (also referred to as the European ADNI study).

METHODS

A total of 147 aMCI patients were enrolled in 13 European memory clinics. Patients underwent clinical and neuropsychological evaluation, magnetic resonance imaging (MRI), electroencephalography (EEG) and lumbar puncture to assess the levels of amyloid β peptide 1-42 (Aβ42), tau and p-tau, and blood samples were collected. Genetic (APOE), neuroimaging (3T morphometry and diffusion MRI) and EEG (with resting-state and auditory oddball event-related potential (AO-ERP) paradigm) biomarkers were evaluated.

RESULTS

Prodromal AD was found in 55 aMCI patients defined by low Aβ42 in the cerebrospinal fluid (Aβ positive). Compared to the aMCI group with high Aβ42 levels (Aβ negative), Aβ positive patients showed poorer visual (P = 0.001), spatial recognition (P < 0.0005) and working (P = 0.024) memory, as well as a higher frequency of APOE4 (P < 0.0005), lower hippocampal volume (P = 0.04), reduced thickness of the parietal cortex (P < 0.009) and structural connectivity of the corpus callosum (P < 0.05), higher amplitude of delta rhythms at rest (P = 0.03) and lower amplitude of posterior cingulate sources of AO-ERP (P = 0.03).

CONCLUSION

These results suggest that, in aMCI patients, prodromal AD is characterized by a distinctive cognitive profile and genetic, neuroimaging and neurophysiological biomarkers. Longitudinal assessment will help to identify the role of these biomarkers in AD progression.

Test-retest reliability of the default mode network in a multi-centric fMRI study of healthy elderly: Effects of data-driven physiological noise correction techniques

Understanding how to reduce the influence of physiological noise in resting state fMRI data is important for the interpretation of functional brain connectivity. Limited data is currently available to assess the performance of physiological noise correction techniques, in particular when evaluating longitudinal changes in the default mode network (DMN) of healthy elderly participants. In this 3T harmonized multisite fMRI study, we investigated how different retrospective physiological noise correction (rPNC) methods influence the within-site test-retest reliability and the across-site reproducibility consistency of DMN-derived measurements across 13 MRI sites. Elderly participants were scanned twice at least a week apart (five participants per site). The rPNC methods were: none (NPC), Tissue-based regression, PESTICA and FSL-FIX. The DMN at the single subject level was robustly identified using ICA methods in all rPNC conditions. The methods significantly affected the mean z-scores and, albeit less markedly, the cluster-size in the DMN; in particular, FSL-FIX tended to increase the DMN z-scores compared to others. Within-site test-retest reliability was consistent across sites, with no differences across rPNC methods. The absolute percent errors were in the range of 5-11% for DMN z-scores and cluster-size reliability. DMN pattern overlap was in the range 60-65%. In particular, no rPNC method showed a significant reliability improvement relative to NPC. However, FSL-FIX and Tissue-based physiological correction methods showed both similar and significant improvements of reproducibility consistency across the consortium (ICC = 0.67) for the DMN z-scores relative to NPC. Overall these findings support the use of rPNC methods like tissue-based or FSL-FIX to characterize multisite longitudinal changes of intrinsic functional connectivity. Hum Brain Mapp 37:2114-2132, 2016. © 2016 Wiley Periodicals, Inc.

Childhood neglect predicts disorganization in schizophrenia through grey matter decrease in dorsolateral prefrontal cortex

OBJECTIVE

Psychosocial trauma during childhood is associated with schizophrenia vulnerability. The pattern of grey matter decrease is similar to brain alterations seen in schizophrenia. Our objective was to explore the links between childhood trauma, brain morphology and schizophrenia symptoms.

METHOD

Twenty-one patients with schizophrenia stabilized with atypical antipsychotic monotherapy and 30 healthy control subjects completed the study. Anatomical MRI images were analysed using optimized voxel-based morphometry (VBM). Childhood trauma was assessed with the Childhood Trauma Questionnaire, and symptoms were rated on the Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS) (disorganization, positive and negative symptoms). In the schizophrenia group, we used structural equation modelling in a path analysis.

RESULTS

Total grey matter volume was negatively associated with emotional neglect (EN) in patients with schizophrenia. Whole-brain VBM analyses of grey matter in the schizophrenia group revealed a specific inversed association between EN and the right dorsolateral prefrontal cortex (DLPFC). Path analyses identified a well-fitted model in which EN predicted grey matter density in DLPFC, which in turn predicted the disorganization score.

CONCLUSION

Our findings suggest that EN during childhood could have an impact on psychopathology in schizophrenia, which would be mediated by developmental effects on brain regions such as the DLPFC.

Structural abnormalities in schizophrenia: further evidence on the key role of the anterior cingulate cortex

OBJECTIVE

The present study examined whole-brain structural abnormalities in schizophrenia, with a special focus on the anterior and posterior cingulate cortex (ACC, PCC) as this is an understudied issue in schizophrenia.

METHOD

Whole-brain voxel-based morphometry analyses of gray matter (GM) and white matter (WM) were performed to detect volumetric differences between 14 patients with schizophrenia and 14 healthy controls matched for age, sex, educational level and parents' educational level. We examined within-group GM and WM correlations and completed the analysis with measurements of sulci in medial cortical areas.

RESULTS

Compared with the healthy controls, the schizophrenic patients showed significant decreases in GM volumes in the ACC and PCC, and in neighboring WM regions such as the corpus callosum and the fimbriae of the fornix. Moreover, the patient group also displayed a negative correlation between volumes of GM and WM in the ACC. Finally, the patients showed significantly reduced volumes in the right cingulate sulci and left inferior frontal sulci.

CONCLUSION

Our results replicate typical brain-structural abnormalities with new findings in the medial prefrontal cortex, suggested to be a key region in this disorder.