Improving Surgical Outcome Using Diffusion Tensor Imaging Techniques in Deep Brain Stimulation

Abstract

IntroductionRecent advances in surgical imaging include the use of diffusion tensor imaging (DTI) in deep brain stimulation (DBS) and provide a detailed view of the white matter tracts and their connections which are not seen with conventional magnetic resonance imaging. Given that the efficacy of DBS depends on the precise and accurate targeting of these circuits, better surgical planning using information obtained from DTI may lead to improved surgical outcome. We aim to review the available literature to evaluate the efficacy of such a strategy.MethodsA search of PubMed was performed to identify all articles using the search terms “(diffusion tractography OR diffusion tensor imaging OR DTI) AND (deep brain stimulation OR DBS).” Studies were included if DTI was used and clinical outcomes were reported.ResultsWe identified 35 studies where the use of DTI in DBS was evaluated. The most studied pathology was movement disorders (17 studies), psychiatric disorders (11 studies), and pain (7 studies). The overall responder rates for tremor reduction was 70.0% (SD = 26.1%) in 69 patients, 36.5% (SD = 19.1%) for obsessive–compulsive disorder in 9 patients, 48.3% (SD = 40.0%) for depression in 40 patients, and 49.7% (SD = 35.1%) for chronic pain in 23 patients.DiscussionThe studies reviewed show that the use of DTI for surgical planning is feasible, provide additional information over conventional targeting methods, and can improve surgical outcome. Patients in whom the DBS electrodes were within the DTI targets experienced better outcomes than those in whom the electrodes were not. Many current studies are limited by their small sample size or retrospective nature. The use of DTI in DBS planning appears underutilized and further studies are warranted given that surgical outcome can be optimized using this non-invasive technique.

Defining the optimal target for anterior thalamic deep brain stimulation in patients with drug-refractory epilepsy

“…38 A review of previous studies utilizing diffusion tensor imaging (DTI) in DBS revealed better outcomes in patients with electrodes within the DTI target. 39 Furthermore, extensive bilateral anterior thalamic volume loss was shown to be a characteristic of temporal lobe epilepsy with mesial temporal sclerosis. 40 As shown, there may be many other factors, including structural changes, that can affect the resulting DBS response and thus the optimal target.…”

Neuroimaging Technological Advancements for Targeting in Functional Neurosurgery

“…Targeting circuits of interest Recent research suggests that optimal structures to be targeted may not be appreciable via routine structural imaging. For example, it has been suggested that the clinical benefits of DBS may be better understood as emerging from white matter pathways [50][51][52][53][54][55] or focal hubs of functional networks [56] rather than discrete structures such as deep grey matter nucleus. Interestingly, when these functional and structural networks are targeted more directly, the resultant target may spatially diverge from conventional coordinates (Table 1).…”

The advances of Deep Brain Stimulation (DBS) for treatment of Parkinson s disease (PD)

“…With advances in tractography, it is also possible to be able to target output and input circuitry as opposed to only the nodes within the BG. Not only is diffusion tensor imaging feasible for surgical planning of movement disorders, psychiatric disorders and pain DBS, but it may also improve surgical outcome 29 .…”

“…The advances in imaging techniques, such as functional MRI and magnetoencephalography, provide tools to better understand connectivity between regions of the brain as well as brain activity associated with electrical stimulation. This information potentially could help in determining better functional and anatomic targets for DBS 29 .…”

“…Khabarova et al 63 [21][22][23][24][25][26][27][28][29][30][31] in those with prior pallidotomy (p < 0.01), and by 37.5%, from 48.8 ± 12.6 (range, 35-65) to 29.8 ± 13.6 (range, in those with prior thalamotomy (p < 0.01). This study indicates that bilateral STN-DBS is effective and can be used in patients with PD with prior unilateral stereotactic destructive operations on subcortical structures.…”