Prefrontal versus motor cortex transcranial direct current stimulation (tDCS) effects on post-surgical opioid use

Abstract

Background Pain is often a complaint that precedes total knee arthroplasty (TKA), however the procedure itself is associated with considerable post-operative pain lasting days to weeks which can predict longer-term surgical outcomes. Previously, we reported significant opioid-sparing effects of motor cortex transcranial direct current stimulation from a single-blind trial. In the present study, we used double-blind methodology to compare motor cortex tDCS and prefrontal cortex tDCS to both sham and active-control (active electrodes over non-pain modulating brain areas) tDCS. Methods 58 patients undergoing unilateral TKA were randomly assigned to receive 4 20-minute sessions (a total of 80 minutes) of tDCS (2mA) post-surgery with electrodes placed to create 4 groups: 1) MOTOR (n=14); anode-motor/cathode-right prefrontal, 2) PREFRONTAL (n=16); anode-left-prefrontal/cathode-right-sensory, 3) ACTIVE-CONTROL (n=15); anode-left-temporal-occipital junction/cathode-medial-anterior-premotor-area, and 4) SHAM (n=13); 0mA-current stimulation using placements 1 or 2. Patient controlled analgesia (PCA; hydromorphone) use was tracked during the ∼72-hours post-surgery. Results Patients in the sham group and the active-control group used 15.4mg (SD=14.1) and 16.0mg (SD=9.7) of PCA hydromorphone respectively. There was no difference between the slopes of the cumulative PCA usage curves between these two groups (p=.25; ns). Patients in the prefrontal tDCS group used an average of 11.7mg (SD=5.0) of PCA hydromporhone, and the slope of the cumulative PCA usage curve was significantly lower than sham (p<.0001). However, patients in the motor tDCS group used an average of 19.6mg (SD=11.9) hydromorphone and the slope of the PCA use curve was significantly higher than sham (p<.0001). Conclusions Results from this double-blind cortical-target-optimization study suggest that anodal transcranial direct current stimulation (tDCS) over the left prefrontal cortex may be a reasonable approach to reducing post-TKA opioid requirements. Given the unexpected finding that motor cortex failed to produce an opioid sparing effect in this follow-up trial, further research in the area of post-operative cortical stimulation is still needed.

Frequency‐dependent top‐down modulation of temporal summation by anodal transcranial direct‐current stimulation of the primary motor cortex in healthy adults

“…They may also provide insight into the efficacy of tDCS in both clinical and nonclinical settings. There is a growing body of evidence that suggests tDCS is more effective in patients with chronic pain Borckardt et al, 2011Borckardt et al, , 2017Jurgens et al, 2012;Kim et al, 2013;Hagenacker et al, 2014;Bolognini et al, 2015;Volz et al, 2016;Ahn et al, 2017;Harvey et al, 2017;Khedr et al, 2017a) compared to studies that have attempted to dissect the analgesic mechanisms in healthy subjects (Boggio et al, 2008;Csifcsak et al, 2009;Hansen et al, 2011;Jurgens et al, 2012;Aslaksen et al, 2014;Ihle et al, 2014). These lines of evidence have now not only shown a reduction in pain intensity in chronic pain patients, but also distinct changes in the brain regions involved in the top-down modulation of pain processing.…”

“…Transcranial direct-current stimulation (tDCS) can modulate cortical activity by depolarizing or hyperpolarizing cortical neuronal resting membrane potentials depending on the polarity of current stimulation (Purpura and McMurtry, 1965;Gorman, 1966). There is a growing body of evidence that anodal tDCS applied over the primary motor cortex provides pain relief in a number of neuropathic, visceral and inflammatory chronic pain conditions (Borckardt et al, 2011(Borckardt et al, , 2017Jurgens et al, 2012;Kim et al, 2013;Hagenacker et al, 2014;Bolognini et al, 2015;Volz et al, 2016;Ahn et al, 2017;Harvey et al, 2017;Khedr et al, 2017a). However, the analgesic mechanisms mediating these effects have been more difficult to elucidate.…”

Postoperative Pain Management in Total Knee Arthroplasty

“…A small amount of analgesic could be delivered by the patients pressing the button when they most need it. Usually, opioids are used in PCA, such as oxycodone, morphine, fentanyl, and hydromorphone. Therefore, PCA is associated with some adverse effects caused by opioids, including nausea, vomiting, respiratory depression, and urinary retention.…”

Patient-Controlled Intravenous Morphine Analgesia Combined with Transcranial Direct Current Stimulation for Post-Thoracotomy Pain: A Cost-Effectiveness Study and A Feasibility for Its Future Implementation

“…The efficacy of transcranial direct current stimulation (tDCS) as an adjuvant nonpharmacological method to conventional regional or systemic analgesia for acute postoperative pain was investigated in seven studies [1][2][3][4][5][6][7]. This was a proof-of-concept clinical trial attempting to explore the impact of tDCS combined with patient controlled intravenous morphine analgesia (PCA-IV) on analgesic use and post-thoracotomy pain.…”

“…The analgesic efficacy of multiple tDCS sessions has been explored in chronic pain states, including fibromyalgia [16], and traumatic spinal cord injury [17]. Consequently, as tDCS has been getting attention for acute postoperative pain management, several studies have suggested that the use of tDCS can contribute to reduced postoperative pain intensity and opioid use [1][2][3][5][6][7]. Thoracotomy is a markedly painful incision because it involves cutting through multiple muscle layers, rib resections, intercostal nerve injury and thoracic drain placement at the end of surgery.…”