Deep Brain Stimulation For Depression Research Articles

Diffusion Tensor Imaging to Aid Subgenual Cingulum Target Selection for Deep Brain Stimulation in Depression

Background: The most investigated target for deep brain stimulation in depression is the subgenual cingulate gyrus (Cg25) which has been shown to be a critical hub for signalling in the condition. Diffusion tensor imaging (DTI) is a form of MR sequence that can visualise white matter connections and potentially aid target selection. Objectives: To assess whether targets selected using DTI to find the area of maximal tract crossover (maximal isotropy) underlying the subgenual cingulum differ significantly in location from those selected using standard T₂ sequences. Methods: Fifty-nine non-depressed adult volunteers underwent MR imaging using T₁, T₂ and DTI sequences of the brain. Each patient had targets selected for both hemispheres using both T₂ and DTI sequences. The significance of the differences in coordinates in all three dimensions was tested using the paired t test. Results: There was a significant difference in the mediolateral (x) and dorsoventral (z) coordinates of DTI targets when compared with T₂ targets (p < 0.001). Conclusions: Targets within Cg25 selected using DTI are significantly different in location from those selected using T₂ sequences and have the potential to enhance treatment outcome by reducing the impact of interindividual variability.

Circuits, Cells, and Synapses: Toward a New Target for Deep Brain Stimulation in Depression

Understanding the pathophysiology of depression requires knowledge of the anatomical pathways that malfunction in this disorder. The anatomy of depression involves limbic and hypothalamic activation mediating stress and anxiety. These interact with cortical areas, primarily the medial prefrontal cortex (mPFC), which appears to mediate the cognitive aspects of depression. The mPFC in turn innervates the thalamus and lateral habenula (l. habenula). The anatomy of melancholia has recently been advanced through an understanding of the role of the l. habenula and incorporation of this structure between the cortical and limbic inputs and the monoaminergic nuclei. The l. habenula controls the midbrain monoaminergic nuclei, whose output pathways interact with each other, as well as providing strong modulatory control of limbic and cortical areas. Recently understanding of how the dopamine system is regulated by the l. habenula in normal (Matsumoto and Hikosaka, 2009) and affectively disturbed states (Li et al, 2011) has been investigated. Over activity in the l. habenula is seen in both the learned helplessness model (Li et al, 2011) and in patients who express depressive symptoms following tryptophan depletion (Roiser et al, 2009). This over activity causes decreased dopaminergic stimuation, suppressing reward signals (Matsumoto and Hikosaka, 2009). It also depresses 5HT signals (Wang and Aghajanian, 1997), which feed back further increasing l. habenular activity. The l. habenula receives strong inputs from both the limbic system, through the basal nucleus of the stria terminalis, which carries information from the amygdala related to anxiety and from the mPFC, which may be related to the cognitive aspects of depression (Li et al, 2011) and sends its output to the midbrain aminergic nuclei.

PL.03.01 Deep brain stimulation for depression: present and future

PL.03.01 Deep brain stimulation for depression: present and future

Deep brain stimulation in clinical trials and animal models of depression

Deep brain stimulation (DBS) is currently being investigated as a therapy for the treatment of depression. Despite promising results of recent clinical trials, neural and chemical mechanisms responsible for the effects of stimulation are still unclear. In this article, we review clinical and laboratory findings on DBS for depression. Particular emphasis will be given to aspects involved in the translation of data from animal models to humans and in our findings on the potential substrates involved in the antidepressant effects of DBS in rats.

Potential surgical targets for deep brain stimulation in treatment-resistant depression

The goal of this study was to evaluate the definition of treatment-resistant depression (TRD), review the literature regarding deep brain stimulation (DBS) for TRD, and identify potential anatomical and functional targets for future widespread clinical application. A comprehensive literature review was performed to determine the current status of DBS for TRD, with an emphasis on the scientific support for various implantation sites. The definition of TRD is presented, as is its management scheme. The rationale behind using DBS for depression is reviewed. Five potential targets have been identified in the literature: ventral striatum/nucleus accumbens, subgenual cingulate cortex (area 25), inferior thalamic peduncle, rostral cingulate cortex (area 24a), and lateral habenula. Deep brain stimulation electrodes thus far have been implanted and activated in only the first 3 of these structures in humans. These targets have proven to be safe and effective, albeit in a small number of cases. Surgical intervention for TRD in the form of DBS is emerging as a viable treatment alternative to existing modalities. Although the studies reported thus far have small sample sizes, the results appear to be promising. Various surgical targets, such as the subgenual cingulate cortex, inferior thalamic peduncle, and nucleus accumbens, have been shown to be safe and to lead to beneficial effects with various stimulation parameters. Further studies with larger patient groups are required to adequately assess the safety and efficacy of these targets, as well as the optimal stimulation parameters and long-term effects.

Changing Tides in Neurosurgical Interventions for Treatment-Resistant Depression

Changing Tides in Neurosurgical Interventions for Treatment-Resistant Depression