Body Weight Changes after Deep Brain Stimulation for Obsessive-Compulsive Disorder or Depression

Anterior Limb of Internal Capsule and Bed Nucleus of Stria Terminalis Stimulation for Gilles de la Tourette Syndrome with Obsessive-Compulsive Disorder in Adolescence: A Case of Success

Gilles de la Tourette syndrome (GTS) is a neurobehavioral disorder comprising motor and vocal tics. In most cases it is associated with other disorders such as obsessive-compulsive disorder (OCD). In refractory cases deep brain stimulation (DBS) is a valid treatment option. This paper describes the case of a 15-year-old adolescent with an extremely refractory GTS with associated OCD. The patient developed catatonia associated with OCD, which partially remitted after electroconvulsive therapy. At the peak of the disease the Yale Global Tic Severity Scale (YGTSS) was 100 and the patient required sedation and intubation. All medical treatment options were unsuccessful. Bilateral DBS of the anterior limb of internal capsule (ALIC)/bed nucleus of stria terminalis (BST) region was performed, using a target below the BST and a trajectory through the ALIC, with stimulation of contacts 0 and 3. Two weeks after surgery sedatives were suspended and the patient was successfully extubated. One year after surgery the patient reached a YGTSS of 19, representing an 81% improvement. OCD completely resolved. Adverse events were a superficial infection and weight gain. In conclusion, this ALIC/BST stimulation appears to have been an effective and safe treatment for GTS with OCD in this case. Young age should not be an exclusion criterion for DBS in severe GTS and OCD. Further studies should be pursued for this target.

Weight Change after Striatal/Capsule Deep Brain Stimulation Relates to Connectivity to the Bed Nucleus of the Stria Terminalis and Hypothalamus

Weight changes are insufficiently understood adverse events of deep brain stimulation. In this context, exploring neural networks of weight control may inform novel treatment strategies for weight-related disorders. In this study, we investigated weight changes after deep brain stimulation of the ventral striatum/ventral capsule and to what extent changes are associated with connectivity to feeding-related networks. We retrospectively analyzed 25 patients undergoing deep brain stimulation for obsessive-compulsive disorder or substance dependency. Weight changes were assessed preoperatively and six to twelve months after surgery and then matched with individual stimulation sites and stimulation-dependent functional connectivity to a priori defined regions of interest that are involved in food intake. We observed a significant weight gain after six to twelve months of continuous stimulation. Weight increases were associated with medial/apical localization of stimulation sites and with connectivity to hypothalamic areas and the bed nucleus. Thus, deep brain stimulation of the ventral striatum/ventral capsule influences weight depending on localization and connectivity of stimulation sites. Bearing in mind the significance of weight-related disorders, we advocate further prospective studies investigating the neuroanatomical and neuropsychological underpinnings of food intake and their neuromodulatory therapeutic potential.

Deep Brain Stimulation for Obesity: A Review and Future Directions

The global prevalence of obesity has been steadily increasing. Although pharmacotherapy and bariatric surgeries can be useful adjuvants in the treatment of morbid obesity, they may lose long-term effectiveness. Obesity result largely from unbalanced energy homeostasis. Palatable and densely caloric foods may affect the brain overlapped circuits involved with homeostatic hypothalamus and hedonic feeding. Deep brain stimulation (DBS) consists of delivering electrical impulses to specific brain targets to modulate a disturbed neuronal network. In selected patients, DBS has been shown to be safe and effective for movement disorders. We review all the cases reports and series of patients treated with DBS for obesity using a PubMed search and will address the following obesity-related issues: (i) the hypothalamic regulation of homeostatic feeding; (ii) the reward mesolimbic circuit and hedonic feeding; (iii) basic concepts of DBS as well as the rationale for obesity treatment; (iv) perspectives and challenges in obesity DBS. The small number of cases provides preliminary evidence for the safety and the tolerability of a potential DBS approach. The ventromedial (n = 2) and lateral (n = 8) hypothalamic nuclei targets have shown mixed and disappointing outcomes. Although nucleus accumbens (n = 7) targets were more encouraging for the outcomes of body weight reduction and behavioral control for eating, there was one suicide reported after 27 months of follow-up. The authors did not attribute the suicide to DBS therapy. The identification of optimal brain targets, appropriate programming strategies and the development of novel technologies will be important as next steps to move DBS closer to a clinical application. The identification of electrical control signals may provide an opportunity for closed-loop adaptive DBS systems to address obesity. Metabolic and hormonal sensors such as glycemic levels, leptin, and ghrelin levels are candidate control signals for DBS. Focused excitation or alternatively inhibition of regions of the hypothalamus may provide better outcomes compared to non-selective DBS. Utilization of the NA delta oscillation or other physiological markers from one or multiple regions in obesity-related brain network is a promising approach. Experienced multidisciplinary team will be critical to improve the risk-benefit ratio for this approach.

An Open-Label Clinical Trial of Hypothalamic Deep Brain Stimulation for Human Morbid Obesity: BLESS Study Protocol

BACKGROUND

Human morbid obesity is increasing worldwide in an alarming way. The hypothalamus is known to mediate its mechanisms. Deep brain stimulation (DBS) of the ventromedial hypothalamus (VMH) may be an alternative to treat patients refractory to standard medical and surgical therapies.

OBJECTIVE

To assess the safety, identify possible side effects, and to optimize stimulation parameters of continuous VMH-DBS. Additionally, this study aims to determine if continuous VMH-DBS will lead to weight loss by causing changes in body composition, basal metabolism, or food intake control.

METHODS

The BLESS study is a feasibility study, single-center open-label trial. Six patients (body mass index > 40) will undergo low-frequency VMH-DBS. Data concerning timing, duration, frequency, severity, causal relationships, and associated electrical stimulation patterns regarding side effects or weight changes will be recorded.

EXPECTED OUTCOMES

We expect to demonstrate the safety, identify possible side effects, and to optimize electrophysiological parameters related to VMH-DBS. No clinical or behavioral adverse changes are expected. Weight loss ≥ 3% of the basal weight after 3 mo of electrical stimulation will be considered adequate. Changes in body composition and increase in basal metabolism are expected. The amount of food intake is likely to remain unchanged.

DISCUSSION

The design of this study protocol is to define the safety of the procedure, the surgical parameters important for target localization, and additionally the safety of long-term stimulation of the VMH in morbidly obese patients. Novel neurosurgical approaches to treat metabolic and autonomic diseases can be developed based on the data made available by this investigation.