Changes in amygdalar functional connectivity following the water load symptom provocation task (WL-SPT) in youth with functional abdominal pain disorders

Pediatric functional abdominal pain disorders (FAPD) are highly prevalent, difficult to diagnose and challenging to treat. The brain mechanisms supporting FAPD remain poorly understood. This investigation examined the neuromechanisms of FAPD during a well-tolerated visceral pain induction task, the water load symptom provocation task (WL-SPT). Youth between the ages of 11 and 17 years participated. Functional connectivity (FC) was examined via the Blood Oxygenation Level Dependent (BOLD) effect using the left and right amygdala (AMY) as seed regions. Relationships of the time courses within these seeds with voxels across the whole brain were evaluated. Arterial spin labeling (ASL) was used to assess regional brain activation by examining cerebral blood flow. Increased FC between the left AMY with regions associated with nociceptive processing (e.g., thalamus), and right AMY FC changes with areas associated with cognitive functioning (dorsolateral prefrontal cortex) and the default mode network (DMN; parietal lobe) were observed in youth with FAPD following the WL-SPT. These changes were related to changes in pain unpleasantness. AMY FC changes post WL-SPT were also related to changes in pain intensity. AMY FC with the DMN in youth with FAPD also differed from healthy controls. Global CBF changes were also noted between FAPD and controls, but no significant differences in grey matter were detected either between groups or during the WL-SPT in youth with FAPD. Findings confirm youth with FAPD have changes in brain connectivity that could support the development of biomarkers to enhance understanding of the mechanisms of pain and treatment response.

Deep brain stimulation in the bed nucleus of the stria terminalis: a symptom provocation study in patients with obsessive-compulsive disorder

BackgroundDeep brain stimulation (DBS) is an emerging therapy for treatment-resistant obsessive-compulsive disorder (OCD), and several targets for electrode implantation and contact selection have been proposed, including the bed nucleus of the stria terminalis (BST). Selecting the active electrode contacts (patients typically have four to choose from in each hemisphere), and thus the main locus of stimulation, can be a taxing process. Here, we investigated whether contact selection based purely on their neuroanatomical position in the BST is a worthwhile approach. For the first time, we also compared the effects of uni- versus bilateral BST stimulation.MethodsNine OCD patients currently receiving DBS participated in a double-blind, randomized symptom provocation study to compare no versus BST stimulation. Primary outcomes were anxiety and mood ratings in response to disorder-relevant trigger images, as well as ratings of obsessions, compulsions, tendency to avoid and overall wellbeing. Furthermore, we asked whether patients preferred the electrode contacts in the BST over their regular stimulation contacts as a new treatment setting after the end of the task.ResultsWe found no statistically significant group differences between the four conditions (no, left, right and bilateral BST stimulation). Exploratory analyses, as well as follow-up data, did indicate that (bilateral) bipolar stimulation in the BST was beneficial for some patients, particularly for those who had achieved unsatisfactory effects through the typical contact selection procedure.ConclusionsDespite its limitations, this study suggests that selection of stimulation contacts in the BST is a viable option for DBS in treatment-resistant OCD patients.

Symptom Provocation During Aerobic and Dynamic Supervised Exercise Challenges in Adolescents With Sport-Related Concussion

Context Supervised exercise challenges (SECs) have been shown to be safe and beneficial in the early symptomatic period after concussion. Thus far, most in-clinic SECs studied have included a form of basic aerobic exercise only. An SEC that also includes dynamic forms of exercise mimics all steps of a standard return-to-play progression and may enhance the detection of concussion symptoms to guide in-clinic management decisions. Objective To determine whether an SEC that includes a dynamic SEC (DSEC) uncovered symptoms that would not have been identified by an SEC involving an aerobic SEC (ASEC) alone in adolescent patients with sport-related concussion. Design Retrospective case series. Setting Multidisciplinary sport concussion clinic at a tertiary care center. Patients or Other Participants A total of 65 adolescent athletes (mean age = 14.9 ± 2.0 years, 72.3% males) who underwent an in-clinic SEC within 30 days of concussion. Main Outcome Measure(s) Presence of pre-exercise symptoms and symptom provocation during the SEC were recorded, with exercise-provoked symptoms categorized as occurring during ASEC or DSEC. Results Of the total patient sample, 69.2% (n = 45/65) experienced symptom provocation at some point during the SEC. Symptoms were provoked in 20 patients during the ASEC, whereas 25 completed the ASEC without symptom provocation before becoming symptomatic during the subsequent DSEC and 20 completed the SEC without any symptom provocation. Of the 65 patients in the total sample, 46 were asymptomatic immediately before the SEC. Of these previously asymptomatic patients, 23.9% (n = 11/46) experienced symptom provocation during the ASEC, and an additional 37.0% (n = 17/46) remained asymptomatic during the ASEC but then developed symptoms during the DSEC. Conclusions The ASEC alone may not detect symptom provocation in a significant proportion of concussion patients who otherwise would develop symptoms during a DSEC.