Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that delivers constant, low electrical current resulting in changes to cortical excitability. Prior work suggests it may enhance motor learning giving it the potential to augment surgical technical skill acquisition. The aim of this study was to test the efficacy of tDCS, coupled with motor skill training, to accelerate laparoscopic skill acquisition in a pre-registered (NCT03083483), double-blind and placebo-controlled study. We hypothesized that relative to sham tDCS, active tDCS would accelerate the development of laparoscopic technical skills, as measured by the Fundamentals of Laparoscopic Surgery (FLS) Peg Transfer task quantitative metrics. In this study, sixty subjects (mean age 22.7 years with 42 females) were randomized into sham or active tDCS in either bilateral primary motor cortex (bM1) or supplementary motor area (SMA) electrode configurations. All subjects practiced the FLS Peg Transfer Task during six 20-min training blocks, which were preceded and followed by a single trial pre-test and post-test. The primary outcome was changes in laparoscopic skill performance over time, quantified by group differences in completion time from pre-test to post-test and learning curves developed from a calculated score accounting for errors. Learning curves calculated over the six 20-min training blocks showed significantly greater improvement in performance for the bM1 group than the sham group (t = 2.07, p = 0.039), with the bM1 group achieving approximately the same amount of improvement in 4 blocks compared to the 6 blocks required of the sham group. The SMA group also showed greater mean improvement than sham, but exhibited more variable learning performance and differences relative to sham were not significant (t = 0.85, p = 0.400). A significant main effect was present for pre-test versus post-test times (F = 133.2, p < 0.001), with lower completion times at post-test, however these did not significantly differ for the training groups. Laparoscopic skill training with active bilateral tDCS exhibited significantly greater learning relative to sham. The potential for tDCS to enhance the training of surgical skills, therefore, merits further investigation to determine if these preliminary results may be replicated and extended.
Anxiety disorders are among the most prevalent psychiatric conditions. Despite many proven pharmacological and non-pharmacological treatments available, high rates of partial response and low rates of long-term remission remain. Ketamine has been receiving increasing attention as an interventional treatment modality in psychiatry, especially among refractory conditions, including major depressive disorder. There is limited yet growing evidence to support the use of ketamine in anxiety disorders. In this review of the literature, we present case reports, case series, and controlled trials demonstrating proof-of-concept for its potential role in the treatment of anxiety and anxiety spectrum disorders. Its unique mechanism of action, rapid onset, and high rate of response have driven its use in clinical practice. Ketamine is generally well tolerated by patients and has a limited side effect profile; however, the effects of long-term use are unknown. While there is a growing body of research and increasing clinical experience to suggest ketamine may have clinical applications in the treatment of refractory anxiety disorders, further research to determine long-term safety and tolerability is indicated.
The U.S. is currently facing an unprecedented epidemic of opioid-related deaths. Despite the efficacy of the current treatments for opioid use disorder (OUD), including psychosocial interventions and medication-assisted therapy (MAT), many patients remain treatment-resistant and at high risk for overdose. A potential augmentation strategy includes the use of non-invasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and auricular vagus nerve stimulation (aVNS). These approaches may have therapeutic benefits by directly or indirectly modulating the neurocircuitry affected in OUD. In this review, we evaluate the available studies on NIBS in the context of OUD withdrawal and detoxification, maintenance, and cravings, while also considering analgesia and safety concerns. In the context of opioid withdrawal and detoxification, a percutaneous form of aVNS has positive results in open-label trials, but has not yet been tested against sham. No randomized studies have reported on the safety and efficacy of NIBS specifically for maintenance treatment in OUD. TMS and tDCS have demonstrated effects on cravings, although published studies were limited by small sample sizes. NIBS may play a role in reducing exposure to opioids and the risk of developing OUD, as demonstrated by studies using tDCS in an experimental pain condition and TMS in a post-operative setting. Overall, while the preliminary evidence and safety for NIBS in the prevention and treatment of OUD appears promising, further research is needed with larger sample sizes, placebo control, and objective biomarkers as outcome measures before strong conclusions can be drawn.
1 November 2021 in The American Journal of Medicine
Objective: Depression and chronic pain are major problems in American veterans, yet there is limited long-term research examining how they relate to one another in this population. This study examined the relationship between depressive symptoms and pain in U.S. veterans 50 years of age or older. Methods: This study used data on veterans from the 2002–2016 waves of the Health and Retirement Study (n = 4,302), a large-scale observational study of Americans 50 years of age or older. Measures included a short form of the Center for Epidemiologic Studies Depression scale and two items assessing the presence and degree of pain. Analyses included random-intercept cross-lagged panel models (RI-CLPM). Results: In the RI-CLPM, there were roughly equivalent cross-lagged effects between depressive symptoms and pain. There was also evidence that depressive symptoms and pain have a trait-like component and that these trait-like characteristics are associated. Conclusions: These findings indicate that depressive symptoms and pain in veterans are stable characteristics in American veterans 50 years of age or older. There appear to be reciprocal effects between the two, whereby deviations in one’s typical depressive symptoms predict subsequent deviations in one’s pain level and vice versa; however, the size of these effects is very small. These findings suggest that clinicians should treat both depressive symptoms and pain, rather than assume that treatment benefits in one domain will lead to major benefits in another.
Tobacco-related deaths remain the leading cause of preventable death in the United States. Veterans suffering from posttraumatic stress disorder (PTSD)—about 11% of those receiving care from the Department of Veterans Affairs (VA)—have triple the risk of developing tobacco use disorder (TUD). The most efficacious strategies being used at the VA for smoking cessation only result in a 23% abstinence rate, and veterans with PTSD only achieve a 4.5% abstinence rate. Therefore, there is a critical need to develop more effective treatments for smoking cessation. Recent studies suggest the insula is integrally involved in the neurocircuitry of TUD. Thus, we propose a feasibility phase II randomized controlled trial (RCT) to study a form of repetitive transcranial magnetic stimulation (rTMS) called intermittent theta burst stimulation (iTBS). iTBS has the advantage of allowing for a patterned form of stimulation delivery that we will administer at 90% of the subject’s resting motor threshold (rMT) applied over a region in the right post-central gyrus most functionally connected to the right posterior insula. We hypothesize that by increasing functional connectivity between the right post-central gyrus and the right posterior insula, withdrawal symptoms and short-term smoking cessation outcomes will improve. Fifty eligible veterans with comorbid TUD and PTSD will be randomly assigned to active-iTBS + cognitive behavioral therapy (CBT) + nicotine replacement therapy (NRT) (n = 25) or sham-iTBS + CBT + NRT (n = 25). The primary outcome, feasibility, will be determined by achieving a recruitment of 50 participants and retention rate of 80%. The success of iTBS will be evaluated through self-reported nicotine use, cravings, withdrawal symptoms, and abstinence following quit date (confirmed by bioverification) along with evaluation for target engagement through neuroimaging changes, specifically connectivity differences between the insula and other regions of interest.