Invasive and Non-invasive Stimulation of the Obese Human Brain

Abstract

Accumulating evidence suggests that non-invasive and invasive brain stimulation may reduce food craving and calorie consumption rendering these techniques potential treatment options for obesity. Non-invasive transcranial direct current stimulation (tDCS) or repetitive transcranial magnet stimulation (rTMS) are used to modulate activity in superficially located executive control regions, such as the dorsolateral prefrontal cortex (DLPFC). Modulation of the DLPFC’s activity may alter executive functioning and food reward processing in interconnected dopamine-rich regions such as the striatum or orbitofrontal cortex. Modulation of reward processing can also be achieved by invasive deep brain stimulation (DBS) targeting the nucleus accumbens. Another target for DBS is the lateral hypothalamic area potentially leading to improved energy expenditure. To date, available evidence is, however, restricted to few exceptional cases of morbid obesity. The vagal nerve plays a crucial role in signaling the homeostatic demand to the brain. Invasive or non-invasive vagal nerve stimulation (VNS) is thus assumed to reduce appetite, rendering VNS another possible treatment option for obesity. Based on currently available evidence, the U.S. Food and Drug Administration recently approved VNS for the treatment of obesity. This review summarizes scientific evidence regarding these techniques’ efficacy in modulating food craving and calorie intake. It is time for large controlled clinical trials that are necessary to translate currently available research discoveries into patient care.

A Systematic Review of Obesity and Binge Eating Associated Impairment of the Cognitive Inhibition System

“…Essential to the downregulation of high-energy food reward, this region has been shown to be critical for dietary self-control ( 82 ). Thus, considered as a key node of eating behavior control, the dorsolateral PFC has been the subject of numerous brain stimulation studies, showing that increased activation of this region allowed an improvement of resistance to food stimuli ( 38 ). In the same vein, higher levels of activity in the dorsolateral PFC were shown to be a good predictor of diet success in obese individuals ( 83 , 84 ).…”

“…Recent brain stimulation studies provided promising results on the control of food craving and food intake ( 38 ). Specifically, studies showed that modulating the dorsolateral prefrontal cortex ( 39 , 40 ), nucleus accumbens ( 41 ), and hypothalamic area ( 42 ) substantially reduced food craving.…”

Autonomic Nervous System

“…While results are mixed, animal model research generally demonstrates decreased food intake and decreased weight gain with VNS (Pelotand Grill 2018; Yao et al 2018). Research in humans has demonstrated greater weight loss for participants receiving vagal nerve block compared to sham (Ikramuddin et al 2014), including sustained weight loss over 18 months (Shikora et al 2015;Pleger 2018). Research in humans has also demonstrated a reduction in appetite and body weight with noninvasive VNS as well (Ruiz-Tovar and Llavero 2016; Pleger 2018).…”

Non-invasive Brain Stimulation in Pediatric Migraine: A Perspective From Evidence in Adult Migraine

“…Moreover, NBS of cortical areas as DLPFC, that has been explored in migraine, was found to be effective for treatment of other conditions, that are comorbid with disease, sharing also a stimulation target employed for migraine treatment, like DLPFC. Among these disorders, in addition to the role played by the psychiatric diseases, of particular importance is obesity which also favors the chronification of migraine (35, 36). Due to the large prevalence of the disease and the disability associated with it, and also considering the parents' relevant fears and concerns regarding pharmacological therapies, especially for continuing preventive treatment, pediatric migraine appears to be an optimal candidate for future studies on therapeutic NIBS.…”