Distribution of electric field in patients with obsessive compulsive disorder treated with deep brain stimulation of the bed nucleus of stria terminalis

Abstract

Background Deep brain stimulation (DBS) is being investigated as a treatment for therapy-refractory obsessive compulsive disorder (OCD). Many different brain targets are being trialled. Several of these targets such as the ventral striatum (including the nucleus accumbens (NAc)), the ventral capsule, the inferior thalamic peduncle, and the bed nucleus of stria terminalis (BNST)) belong to the same network, are anatomically very close to one another, or even overlap. Data is still missing on how various stimulation parameters in a given target will affect surrounding anatomical areas and impact the clinical outcome of DBS. Methods In a pilot study of eleven participants with DBS of the BNST, we investigate through patient-specific simulation of electric field, which anatomical areas are affected by the electric field, and if this can be related to the clinical results. Our study combined individual patient’s stimulation parameters at 12- and 24-month follow-up with image data from the preoperative MRI and postoperative CT. These data were used to calculate the distribution of electric field and create individual anatomical models of the field of stimulation. Results The individual electric stimulation fields by stimulation in the BNST were similar at both the 12- and 24-month follow-up, involving mainly anterior limb of the internal capsule (ALIC), genu of the internal capsule (IC), BNST, fornix, anteromedial globus pallidus externa (GPe), and the anterior commissure. A statistical significant correlation (p < 0.05) between clinical effect measured by the Yale-Brown Obsessive Compulsive Scale and stimulation was found at the 12-month follow-up in the ventral ALIC and anteromedial GPe. Conclusions Many of the targets under investigation for OCD are in anatomical proximity. As seen in our study, off-target effects are overlapping. Therefore, DBS in the region of ALIC, NAc, and BNST may perhaps be considered to be stimulation of the same target.

Abnormal White Matter Microstructure in the Limbic System Is Associated With Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders

“…All the prefrontal cortex fibers (both ascending and descending) are projecting to the ALIC, which is one of the most established targets of deep brain stimulation (DBS) or other neuro-surgical treatment for neuropsychiatric disorders ( 26 , 83 ). The dysfunction of the cortico-striato-thalamo-cortical (CSTC) loop is common model for neuropsychiatric disorders ( 84 ). Recently, the effects of DBS to the ALIC, the nucleus accumbens (NAcc), basolateral amygdala, and hypothalamus for self-injury behavior in subjects with ASD were reported ( 85 , 86 ), and these areas are in anatomical proximity with the targets of DBS for obsessive compulsive disorder(OCD) ( 87 ).…”

Deep Brain Stimulation: Emerging Tools for Simulation, Data Analysis, and Visualization

“…Several targets have also been proposed and evaluated for OCD ( Wu et al, 2021 ). Recently, the bed nucleus of stria terminalis (BNTS) and the anteromedial limbic STN were suggested as targets for DBS in OCD ( Naesstrom et al, 2021 ). Sullivan et al (2021) proposed widening the anatomical perspective with focus on brain targets to also include cognitive networks in the search for further understanding of DBS in psychiatric disorders.…”

“…Quantitative measures of wrist movements with accelerometers ( Figure 5A ) were automatically linked to intraoperative test stimulations to find a threshold with the clinical effect ( Hemm et al, 2016 ). Patient-specific electric field studies have been applied for both movement disorders such as PD and ET ( Åström et al, 2010 ; Alonso et al, 2018 ; Göransson et al, 2021 ; Stenmark Persson et al, 2021 ) and in relation to psychiatric indication such as GTS ( Wårdell et al, 2015 ; Akbarian-Tefaghi et al, 2017 ) and OCD ( Naesstrom et al, 2021 ).…”

“…To estimate the electrical effect of stimulation in a patient, several authors include the location and symptomatic effect of the contact of the electrode used for long-term stimulation ( Fytagoridis et al, 2013 ; Lalys et al, 2013 ). In contrast, a more precise estimation can be done by using in silico simulations of single patient distribution of the EF ( Åström et al, 2010 , 2018 ; Hemm et al, 2016 ; Akbarian-Tefaghi et al, 2017 ; Naesstrom et al, 2021 ). Implementation of this method can also be expanded to visualize induced improvements and adverse effects in patient-specific stimulation maps ( Shah et al, 2020 ).…”

Deep brain stimulation in the ALIC-BNST region targeting the bed nucleus of stria terminalis in patients with obsessive–compulsive disorder: effects on cognition after 12 months

“…Table 2 describes in detail the position of active electrodes, stimulation settings, and structures reached by the field of stimulation in each of the eight patients. See Naesström et al [38] for a more thorough presentation.…”