Background: Anorexia nervosa (AN) is a severe and life-threatening psychiatric disorder. Initial studies on deep brain stimulation (DBS) in severe, treatment-refractory AN have shown clinical effects. However, the working mechanisms of DBS in AN remain largely unknown. Here, we used a task-based functional MRI approach to understand the pathophysiology of AN.
Methods: We performed functional MRI on four AN patients that participated in a pilot study on the efficacy, safety, and functional effects of DBS targeted at the ventral limb of the capsula interna (vALIC). The patients and six gender-matched healthy controls (HC) were investigated at three different time points. We used an adapted version of the monetary incentive delay task to probe generic reward processing in patients and controls, and a food-specific task in patients only.
Results: At baseline, no significant differences for reward anticipation were found between AN and HC. Significant group (AN and HC) by time (pre- and post-DBS) interactions were found in the right precuneus, right putamen, right ventral and medial orbitofrontal cortex (mOFC). No significant interactions were found in the food viewing task, neither between the conditions high-calorie and low-calorie food images nor between the different time points. This could possibly be due to the small sample size and the lack of a control group.
Conclusion: The results showed a difference in the response of reward-related brain areas post-DBS. This supports the hypotheses that the reward circuitry is involved in the pathogenesis of AN and that DBS affects responsivity of reward-related brain areas. Trial registration Registered in the Netherlands Trial Register ( https://www.trialregister.nl/trial/3322 ): NL3322 (NTR3469).
Keywords: Anorexia nervosa; Body Mass Index; Brain networks; Clinical trial; Deep brain stimulation; Functional neuroimaging; Neurosurgery; Reward; Treatment-refractory.
Anorexia Nervosa (An) is a severe eating disorder with many, sometimes life-threatening, complications. A substantial number of AN patients do not respond to the available treatment options and remain chronically ill or even die as a consequence of the AN. Because part of the causes of AN may reside in the brain, we studied the efficacy and safety of a potential new treatment option for AN, namely deep brain stimulation (DBS). DBS has proven to be an effective treatment option for movements disorders like Parkinson’s Disease and other psychiatric disorders such as obsessive compulsive disorder. Our previous pilot study and other research have shown that DBS leads to improvements in weight, mood, anxiety, and eating disorder symptoms. In this substudy, we examined the effects of DBS on specific brain circuitries that are implicated in AN. We conducted brain scans (fMRI) to measure brain activity while patients performed tasks. We observed a difference in brain response when we compared scans taken before and after the DBS, which supports our thoughts on the involvement of specific parts of the brain in AN.
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