Shirley Fecteau

Chronic low back pain (CLBP) presents a major challenge in pain management, often persisting despite standard therapies. Peripheral nerve field stimulation (PNFS), also known as subcutaneous stimulation, offers a minimally invasive neuromodulation approach that may improve outcomes for these patients. This systematic review evaluates the evidence on PNFS, alone or combined with spinal cord stimulation (SCS), for CLBP, focusing on pain relief, functional outcomes, and safety. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, databases including Cochrane, Embase, MEDLINE (PubMed), and the Université Laval Library were searched for studies from January 2014 to April 2025. Nineteen studies (randomized controlled trials, cohort studies, and case series) were included. Outcomes assessed included pain intensity, disability (Oswestry Disability Index), quality of life (36-Item Short Form Health Survey, EuroQol 5-Dimension), and adverse events. Across study-level estimates, PNFS monotherapy most commonly produced approximately 40% to 60% reductions in pain intensity, although reported effects varied across studies and were not pooled because of heterogeneity. Functional gains included reduced disability and improved mobility. Quality of life measures and medication use often improved. Peripheral nerve field stimulation combined with SCS yielded mixed results, providing benefits particularly for patients unresponsive to SCS alone. Reported complication rates were generally modest, with infections and lead migrations being the most common. Peripheral nerve field stimulation appears to be a promising and generally well-tolerated option for selected patients with CLBP, although evidence certainty remains limited, and larger controlled studies are needed.

Background: Investigation of the neural substrates of post-traumatic stress disorder (PTSD) in military personnel using whole-brain approaches remains scarce, hindering the development of circuit-based neuromodulatory interventions. Objectives: This study aimed to identify potential associations between clinical symptoms and whole-brain resting-state functional connectivity with magnetic resonance imaging in military personnel with adulthood-onset war-related PTSD. Methods: Thirty-seven soldiers from the Canadian Armed Forces with moderate to severe treatment-resistant PTSD participated in this study. We assessed PTSD, anxiety and depressive symptoms, quality of life, and time since trauma. We characterized the whole-brain functional connectome using independent component analysis and regions of interest (ROI)-to-ROI connectivity, as well as its topology using graph theory. Results: Greater severity of PTSD and anxiety symptoms was associated with lower connectivity ( r < 0) between the default mode network (DMN) and frontoparietal network. Greater severity of PTSD symptoms was also associated with a higher nodal clustering coefficient of the inferior parietal lobule from the DMN. Greater severity of anxiety symptoms and longer time since trauma was the only clinical variables that correlated with higher connectivity patterns, all involving the visual networks (the frontoparietal-visual, the visual-DMN, and within-visual networks). Conclusions: This work contributes to identifying brain targets for the development of personalized neuromodulatory interventions. In particular, the DMN may be a promising target to alleviate PTSD symptoms, and the visual network may be a target to treat comorbid anxiety symptoms.

Background: Tobacco use disorder (TUD) is the largest premature cause of death in the world. While most adults with TUD have attempted to quit, only less than 10% quit for at least 6 months. Craving is one of the main causes of smoking relapses. Event-related potentials (ERPs) have been extensively studied using cue-provoked paradigms. However, little is known about ERPs related to resisting craving, which seems important to investigate since such activity might represent treatment targets to promote smoking cessation. Aims: The goal of this work was to investigate the ERP correlates of resisting craving as compared to craving during a cue-provoked paradigm. Methods: Fifty-three adults with TUD were assessed on urinary cotinine, tobacco dependence, anxiety, and impulsivity. They were presented with cigarette-related stimuli during two conditions (Crave and Resist craving). Craving ratings were collected on visual analog scales. EEG was recorded using 64 Ag–AgCl electrodes. Results: Results revealed that P3 and early late positive potential (LPP) amplitudes were smaller during the Resist than the Crave conditions. P1 and late LPP amplitudes were also smaller but did not survive correction for multiple comparisons. Furthermore, anxiety level was related to the P3 amplitude during the Resist and Crave conditions, but did not survive correction for multiple comparisons. Conclusion: This line of work contributes to the identification of potential brain targets to help patients with TUD resist craving.

Parkinson’s disease (PD) is characterized by the progressive loss of dopamine (DA) neurons of the substantia nigra pars compacta (SNc), leading to the appearance of debilitating motor symptoms, in addition to nonmotor symptoms.^1,2 This neurodegenerative disorder is incurable, and although some motor symptoms can be alleviated by the administration of the DA metabolic precursor levodopa, such pharmacotherapy eventually leads to adverse side effects in the form of dyskinesias, leaving very limited options for alternative treatments.^{3 – 6} As the second most common neurodegenerative disease next to Alzheimer’s disease (AD), it is a burden on healthcare services worldwide, especially with the rapidly increasing aging population.⁷ For this reason, research efforts are being made to find alternative ways to detect PD, alleviate its symptoms, slow its progression, and find a cure.

Introduction: Transcranial direct current stimulation (tDCS) applied over the dorsolateral prefrontal cortex (DLPFC) at rest can influence behaviors. However, its mechanisms remain poorly understood. This study examined the effect of a single session of tDCS over the bilateral DLPFC on resting-state functional connectivity using fMRI (rs-fcMRI) during and after stimulation in healthy adults. We also investigated whether baseline rs-fcMRI predicted tDCS-induced changes in rs-fcMRI. Methods: This was a randomized, sham-controlled, double-blind, crossover study. We delivered tDCS for 30 min at 1 mA with the anode and cathode over the left and right DLPFC, respectively. We used seed-based analyses to measure tDCS-induced effects on whole-brain rs-fcMRI using a 3 (before, during, after stimulation) × 2 (active, sham stimulation) ANOVA. Results: There were four significant Time × Stimulation interactions on the connectivity scores with the left DLPFC seed (under the anode electrode) and no interactions for the right DLPFC seed (under the cathode electrode). tDCS changed rs-fcMRI between the left DLPFC seed and parieto-occipital, parietal, parieto-occipitotemporal, and frontal clusters during and after stimulation, as compared to sham. Furthermore, rs-fcMRI prior to stimulation predicted some of these tDCS-induced changes in rs-fcMRI during and after stimulation. For instance, rs-fcMRI of the fronto-parietooccipital network predicted changes observed after active stimulation, rs-fcMRI of the fronto-parietal network predicted changes during active stimulation, whereas rs-fcMRI of the fronto-parieto-occipitotemporal and the frontal networks predicted changes both during and after active stimulation. Discussion: Our findings reveal that tDCS modulated rs-fcMRI both during and after stimulation mainly in regions distal, but also in those proximal to the area under the anode electrode, which were predicted by rs-fcMRI prior to tDCS. It might be worth considering rs-fcMRI to optimize response to tDCS.

The use of tools to perturb brain activity can generate important insights into brain physiology and offer valuable therapeutic approaches for brain disorders. Furthermore, the potential of such tools to enhance normal behavior has become increasingly recognized, and this has led to the development of various noninvasive technologies that provides a broader access to the human brain. While providing a brief survey of brain manipulation procedures used in the past decades, this review aims at stimulating an informed discussion on the use of these new technologies to investigate the human. It highlights the importance to revisit the past use of this unique armamentarium and proceed to a detailed analysis of its present state, especially in regard to human behavioral regulation.

Patients with posttraumatic stress disorder (PTSD) display several structural brain differences when compared with healthy individuals. However, findings are particularly inconsistent for soldiers with PTSD. Here, we characterized the brain morphometry of 37 soldiers from the Canadian Armed Forces with adulthood war‐related PTSD using structural magnetic resonance imaging. We assessed time since trauma, as well as PTSD, depressive, and anxiety symptoms with the Modified PTSD Symptoms Scale, Beck Depression Inventory, and Beck Anxiety Inventory, respectively. Whole‐brain morphometry was extracted with FreeSurfer and compared with a validated normative database of more than 2700 healthy individuals. Volume and thickness from several regions differed from the norms. Frontal regions were smaller and thinner, particularly the superior and rostral middle frontal gyri. Furthermore, smaller left rostral middle frontal gyrus, left pericalcarine cortex, and right fusiform gyrus were associated with more recent trauma. All subcortical structures were bigger, except the hippocampus. These findings suggest a particular brain morphometric signature of PTSD in soldiers. Smaller and thinner frontal and larger subcortical regions support impaired top‐down and/or downregulation of emotional response in PTSD. Finally, the correlation of smaller frontal, temporal, and occipital regions with more recent trauma might inform future therapeutic approaches.