Tractography-assisted deep brain stimulation of the superolateral branch of the medial forebrain bundle (slMFB DBS) in major depression

• Published in: NeuroImage clinical Vol. 20; pp. 580 - 593
• Main Authors: Coenen, Volker A., Sajonz, Bastian, Reisert, Marco, Bostroem, Jan, Bewernick, Bettina, Urbach, Horst, Jenkner, Carolin, Reinacher, Peter C., Schlaepfer, Thomas E., Mädler, Burkhard
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.01.2018; Elsevier
• Subjects: Adult; Aged; Cohort Studies; Deep brain stimulation; Deep Brain Stimulation - methods; Depression; Depressive Disorder, Major - diagnostic imaging; Depressive Disorder, Major - surgery; Diffusion tensor imaging; Diffusion Tensor Imaging - methods; Female; Fiber tracking; Humans; Intraoperative Neurophysiological Monitoring - methods; Male; Medial forebrain bundle; Medial Forebrain Bundle - diagnostic imaging; Medial Forebrain Bundle - surgery; Microelectrodes; Middle Aged; OCD; Radiology; Regular; slMFB; Stereotactic surgery; Tractography; IPG; VTA; Deep brain stimulation; MRI; VAT; MDD; STN; FT; Fiber tracking; DBS; slMFB; EC; DTI FT; Medial forebrain bundle; Tractography; Depression; MADRS; Stereotactic surgery; Diffusion tensor imaging; OCD; CT; Hz; mA; SNr; μs; DTI; MCP; RN; HF; magnetic resonance imaging; substantia nigra pars reticulata; Montgomery-Åsberg Depression Rating Scale; milli-ampere; mid-commissural point; effective contact; computed tomography; internal pulse generator; Hertz [1/s]; high frequency; micro second; diffusion tensor magnetic resonance imaging; red nucleus; DTI fiber tractography; major depressive disorder; ventral tegmental area; subthalamic nucleus; fiber tractography; volume of activated tissue; DBS, deep brain stimulation; MADRS, Montgomery-Åsberg Depression Rating Scale; VTA, ventral tegmental area; μs, micro second; CT, computed tomography; EC, effective contact; STN, subthalamic nucleus; DTI FT, DTI fiber tractography; FT, fiber tractography; RN, red nucleus; mA, milli-ampere; IPG, internal pulse generator; MDD, major depressive disorder; DTI, diffusion tensor magnetic resonance imaging; Hz, Hertz [1/s]; HF, high frequency; VAT, volume of activated tissue; MRI, magnetic resonance imaging; SNr, substantia nigra pars reticulata; MCP, mid-commissural point
• ISSN: 2213-1582; 2213-1582
• DOI: 10.1016/j.nicl.2018.08.020

Deep brain stimulation (DBS) of the superolateral branch of the medial forebrain bundle (slMFB) emerges as a - yet experimental - treatment for major depressive disorder (MDD) and other treatment refractory psychiatric diseases. First experiences have been reported from two open label pilot trials in major depression (MDD) and long-term effectiveness for MDD (50 months) has been reported. To give a detailed description of the surgical technique for DBS of the superolateral branch of the medial forebrain bundle (slMFB) in MDD. Surgical experience from bilateral implantation procedures in n = 24 patients with MDD is reported. The detailed procedure of tractography-assisted targeting together with detailed electrophysiology in 144 trajectories in the target region (recording and stimulation) is described. Achieved electrode positions were evaluated based on postoperative helical CT and fused to preoperative high resolution anatomical magnetic resonance imaging (MRI; Philips Medical Systems, Best, Netherlands), including the pre-operative diffusion tensor imaging (DTI) tractographic information (StealthViz DTI, Medtronic, USA; Framelink 5.0, Medtronic, USA). Midcommissural point (MCP) coordinates of effective contact (EC) location, together with angles of entry into the target region were evaluated. To investigate incidental stimulation of surrounding nuclei (subthalamic nucleus, STN; substantia nigra, SNr; and red nucleus, RN) as a possible mechanism, a therapeutic triangle (TT) was defined, located between these structures (based on MRI criteria in T2) and evaluated with respect to EC locations. Bilateral slMFB DBS was performed in all patients. We identified an electrophysiological environment (defined by autonomic reaction, passive microelectrode recording, acute effects and oculomotor effects) that helps to identify the proper target site on the operation table. Postoperative MCP-evaluation of effective contacts (EC) shows a significant variability with respect to localization. Evaluation of the TT shows that responders will typically have their active contacts inside the triangle and that surrounding nuclei (STN, SNr, RN) are not directly hit by EC, indicating a predominant white matter stimulation. The individual EC position within the triangle cannot be predicted and is based on individual slMFB (tractography) geometry. There was one intracranial bleeding (FORESEE I study) during a first implantation attempt in a patient who later received full bilateral implantation. Typical oculomotor side effects are idiosyncratic for the target region and at inferior contacts. The detailed surgical procedure of slMFB DBS implantation has not been described before. The slMFB emerges as an interesting region for the treatment of major depression (and other psychiatric diseases) with DBS. So far it has only been successfully researched in open label clinical case series and in 15 patients published. Stimulation probably achieves its effect through direct white-matter modulation of slMFB fibers. The surgical implantation comprises a standardized protocol combining tractographic imaging based on DTI, targeting and electrophysiological evaluation of the target region. To this end, slMFB DBS surgery is in technical aspects comparable to typical movement disorder surgery. In our view, slMFB DBS should only be performed under tractographic assistance. [Display omitted] •The slMFB is an emerging target for DBS in therapy refractory Depression.•The therapeutic effect is related to modulation of white matter.•Surgery for slMFB DBS is tractography assisted surgery.•DBS of the slMFB is in many aspects similar to movement disorder surgery.