Bipolar Directional Deep Brain Stimulation in Essential and Parkinsonian Tremor

Abstract

Objective To compare directional monopolar, bipolar, and directional bipolar thalamic deep brain stimulation (DBS) in tremor patients. Methods Fourteen tremor patients (7 Essential Tremor and 7 Parkinson's Disease) implanted with directional DBS electrodes in the ventral intermediate nucleus (VIM) were enrolled. Side‐effect thresholds of monopolar directional stimulation (DIRECT) were compared to circular DBS as well as, in a randomized design, to those of two different bipolar stimulation settings (BIPOLAR = circular anode; BI‐DIRECT = directional anode). Tremor suppression (Tremor Rating Scale, TRS) right below the side‐effect threshold was also assessed. Results Directional DBS in the individually best direction showed higher side‐effect thresholds than circular DBS (p = 0.0063). The thresholds were raised further using either one of the bipolar stimulation paradigms (BIPOLAR p = 0.0029, BI‐DIRECT p = 0.0022). The side‐effect thresholds did not differ between both bipolar settings, but side‐effects were less frequent with BI‐DIRECT. No difference in TRS scores with stimulation just below the side‐effect threshold was found between all stimulation conditions. Conclusions Side‐effect thresholds of monopolar directional and bipolar stimulation with both circular and directional anodes were higher compared to traditional monopolar circular stimulation in the VIM. Bipolar DBS with directional anodes evoked side‐effect less frequently than bipolar and monopolar directional stimulation. All stimulation settings had comparable effects on tremor suppression just below their side‐effect thresholds. Thus, directional and different bipolar settings should be explored in patients with bothersome side‐effects of thalamic stimulation when monopolar stimulation settings are not satisfying. Further studies are needed to explore the efficiency of the different bipolar stimulation paradigms.

Tremor and Quality of Life in Patients With Advanced Essential Tremor Before and After Replacing Their Standard Deep Brain Stimulation With a Directional System

“…A number of studies using directional DBS leads (d-leads) in the Vim for tremor (15)(16)(17)22) and the STN for Parkinson's disease have been published (16,(23)(24)(25)(26). Most demonstrated a theoretical superiority of d-leads over standard leads with a wider therapeutic window and lower therapeutic current strength or lower total electric energy delivered.…”

“…All leads ( n = 12) were replaced within 2 mm of the original lead and none were excluded from the study. Patients received a rotational fluoroscopy using a flat panel detector C‐arm system (Allura Xper FD20; Phillips Healthcare) three days to three weeks after surgery to determine the rotational orientation of the directional leads (21).…”

Temporal Stability of Lead Orientation in Directional Deep Brain Stimulation

“…Directional deep brain stimulation (DBS) with radially segmented leads is a novel technique that facilitates steering the electric field in the axial plane; the stimulation thus conforms better to the target volume and avoids current spread to non-target tissue [1][2][3]. Although several studies have confirmed that directional DBS can help reduce side effects and widen the therapeutic window [4][5][6][7][8], programming directional DBS remains complex due to the number of possible stimulation settings. It has been pointed out that precise knowledge of the orientation of the segmented electrode can help to find the optimal stimulation parameters and understand the observed DOI: 10.1159/000510883 stimulation effects [9][10][11].…”

Beneficial effect of 24-month bilateral subthalamic stimulation on quality of sleep in Parkinson’s disease

“…Subthalamic nucleus (STN) deep brain stimulation (DBS) is a safe and effective treatment option improving quality of life (QoL) [18], motor [28], and non-motor symptoms (NMS) [14] in patients with advanced Parkinson's disease (PD) who suffer from motor complications or pharmacotherapy-refractory tremor [46].…”