An interventional study of Spinal Cord Stimulator in Pain, Intractable, sponsored by Seoul National University. Terminated at 1 site in Korea, Republic of. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2022-11-08.
Sponsored by Seoul National University · Not applicable, Interventional, and Treatment
The purpose of this study is to explore which mode is effective in the management of intractable chronic pain, the high-density stimulation or the conventional stimulation, in patients who undergo SCS implantation after successful pre-implantation SCS trial.
Since its introduction in 1967 (1), spinal cord stimulation (SCS) has become a well-established modality for the treatment of chronic neuropathic back and leg pain, including postlaminectomy syndrome, complex regional pain syndrome, ext. (2-5) The mechanism of action remains poorly understood but is thought to involve a combination of local neural inhibition, excitation of nearby axons, changes in neurotransmitter physiology, and jamming of pathological network activity by masking intrinsic patterns of neural activity (6). It is generally agreed that a sensory percept (paresthesia) covering the region of pain is required in order to achieve maximal effectiveness (3,7), and as a result, conventional SCS settings typically consist of intermediate frequencies (40-60 Hz), relatively long pulse width (300-500 μsec), and amplitude high enough to induce a sensory percept in the distribution of the patient's pain (2,3,5). However, paresthesia can produce some degree of discomfort, particularly with changes in position and variability of activities (8). Consequently, sometimes there is a trade-off between pain relief and paresthesia discomfort, and the clinical benefits can be offset by the side-effects of the stimulation. Recent studies have attempted to deliver energy to the spinal cord below the threshold for paresthesia ("paresthesia-free" stimulation), with variable degrees of success in the control of neuropathic pain. For example, De Ridder et al. described "burst" stimulation (trains of five pulses) in 12 patients, resulting in paresthesia-free pain relief that was superior to conventional settings (9). In a multicenter prospective study, Al-Kaisy et al. evaluated 10 kHz SCS (HFSCS) delivered below the sensory threshold and documented a long-term reduction in the mean intensity of chronic back pain (10). However, a randomized, double-blind, placebo-controlled crossover study comparing 5 kHz high-frequency subthreshold stimulation to placebo found no significant difference between the two modalities, with a tendency for better results during the first treatment administered, which suggests a strong placebo effect (11). Another randomized controlled, double-blinded, crossover study showed that subthreshold stimulation had significantly lower pain relief than the conventional, supra-threshold SCS (12). Notably, both studies included participants treated with conventional stimulation parameters and did not perform a "trial" to confirm that the study population would, in fact, demonstrate a response to subthreshold stimulation. Most systematic studies of paresthesia-free stimulation employed a high rate of energy delivery (high-density [HD] stimulation) that either required the development of specialized hardware (9,10) or modification of existing systems to allow parameters outside of normal clinical use (11). However, it is possible that rechargeable stimulators currently in widespread use may be able to deliver sufficient energy to accomplish pain relief without paresthesia in appropriately selected patients. Additionally, response to subthreshold stimulation might be heterogeneous in unpredictable ways, which implies that there might be a subset of patients who respond to the therapy better than others.
Patients with chronic intractable pain who meets the Korean SCS Reimbursement Guideline as follows:
(Korea SCS Reimbursement Guideline)
Exclusion Criteria:
Spinal cord stimulator (SCS) implantation with conventional stimulation mode therapy during 2 weeks followed by 2 weeks with high-density stimulation mode therapy.
Device: Spinal Cord Stimulator
Spinal cord stimulator (SCS) implantation with high-density stimulation mode therapy during 2 weeks followed by 2 weeks with conventional stimulation mode therapy.
Device: Spinal Cord Stimulator
Implantation of spinal cord stimulator in patients included in the study and divided in conventional and high density stimulation groups
Also known as: Conventional stimulation mode, High density stimulation mode
Percentage of high density SCS mode selected by participants
Patients will be questioned about the more effective mode of pain relief between conventional and high density stimulation.
Time frame: Four weeks after randomization
Difference of pain intensity between the baseline screening and the evaluation at each visit
Pain intensity will be evaluated using NRS (0-10) pain score
Time frame: Six month from baseline screening
Change of pain characteristics between the baseline screening and the evaluation at each visit
The pain characteristics will be evaluated using PainDETECT
Time frame: Six month from baseline screening
The ability in daily living
Measured by the Korean version of the Instrumental Activities of Daily Living (K-IADL) scale. The IADL require complex thinking skills, including organizational skills and they measure the ability of the person to live independently without the assistance of another person. The IADL scale includes 8 categories labeled from A to H (A. Ability to Use Telephone, B. Shopping, C. Food preparation, D. Housekeeping, E. Laundry, F. Mode of transportation, G. Responsibility for Own Medication and H. Ability to Handle Finances). For each category, the patient should mark the description that resembles the highest functional level (either 0 or 1). A summary score ranges from 0 (low function, dependent) to 8 (high function, independent) for women and 0 through 5 for men to avoid potential gender bias.
Time frame: Screening and follow up at 1 month, 3 months and 6 months
The current pain intensity and interference status
The Brief Pain Inventory Short-Form (BPI-SF) scale measures the pain intensity (severity) and the impact of pain on functioning (interference). Includes a screening question about the pain on the day, pain drawing diagrams, four items about pain intensity (worst pain, least pain, average pain, pain right now), two items on pain relief treatment or medication, and one item on pain interference, with seven sub-items (general activity, mood, walking ability, normal walk, relations with other people, sleep, and enjoyment of life). Each item for pain severity is rated from 0, no pain, to 10, pain as bad as you can imagine, and contributes with the same weight to the final score (0 to 40). The seven subitems of pain interference are rated from 0, does not interfere, to 10, completely interferes, and contributes with the same weight to the final score (0 to 70). The first item, pain drawing diagrams and the items on pain relief treatment or medication do not contribute to the scoring.
Time frame: Screening and follow up at 1 month, 3 months and 6 months
Subjective sleep quality
The difference of Insomnia Severity Index (ISI) between the baseline screening and the evaluation at 1 month, 3 months and 6 months follow up visits
Time frame: Screening and follow up at 1 month, 3 months and 6 months
Oswestry Disability Index
The difference of Oswestry Disability Index between the baseline screening and the evaluation at 1 month, 3 months and 6 months follow up visits
Time frame: Screening and follow up at 1 month, 3 months and 6 months
Beck Depression Inventory
The difference of Beck Depression Inventory between the baseline screening and the evaluation at 1 month, 3 months and 6 months follow up visits
Time frame: Screening and follow up at 1 month, 3 months and 6 months
Pain Catastrophizing scale
Pain catastrophizing is characterized by the tendency to magnify the threat value of a pain stimulus and to feel helpless in the presence of pain, as well as by a relative inability to prevent or inhibit pain-related thoughts in anticipation of, during, or following a painful event. The Pain Catastrophizing Scale (PCS) is a 13-item instrument derived from definitions of catastrophizing described in the literature. The PCS ask participants to reflect on past painful experiences, and to indicate the degree to which they experienced each of 13 thoughts or feelings when experiencing pain, on 5-point scales from (0) not at all and (4) all the time. The PCS total score is computed by summing responses to all 13 items, total scores range from 0 - 52. The PCS subscales are computed as follows: Rumination: Sum of items 8, 9, 10, 11 Magnification: Sum of items 6, 7, 13 Helplessness: Sum of items 1, 2, 3, 4, 5, 12 Total score \<30= Negative and ≥30= Positive for catastrophizing
Time frame: Screening and follow up at 1 month, 3 months and 6 months
The Connor-Davidson Resilience Scale (CD-RISC)
Resilience embodies the personal qualities that enable one to thrive in the face of adversity. The Connor-Davidson Resilience Scale (CD-RISC) contains 25 items, all of which carry a 5-point range of responses, as follows: not true at all (0), rarely true (1), sometimes true (2), often true (3), and true nearly all the time (4). The scale is rated based on how the subject has felt over the past month. The total score ranges from 0-100, with higher scores reflecting greater resilience.
Time frame: Screening and follow up at 1 month, 3 months and 6 months
Patient Global Impression of Change (PGIC)
The overall change in patient's pain for 6 months after the study unblinding, during the follow up visits
Time frame: Follow up visits 1 month, 3 months and 6 months
Clinical Global Impressions-Improvement (CGI-I)
The overall change in patient's improvement for 6 months after the study unblinding, during the follow up visits
Time frame: Follow up visits 1 month, 3 months and 6 months
Patient's satisfaction with the stimulation mode
The difference in the patient's satisfaction evaluated during the follow-up visits using a 5-point Likert scale (5: very satisfied, 4: somewhat satisfied, 3: Dissatisfied, 1: very unsatisfied)
Time frame: Follow up visits 1 month, 3 months and 6 months
Any change of pain medication
The difference between the baseline screening and the evaluation at each visit
Time frame: Six month from baseline screening
Pain area coverage by the SCS
The difference between crossover and follow-up visits (total of 5 times evaluation) by the patient drawing the area of pain coverage. The ideal treatment with SCS will be a total coverage of the pain area, however, sometimes the covered area does not perfectly match with the stimulated area (less or more area). Therefore, a simple drawing of a human body will be presented to the patients who will draw the area of pain and then the coverage of the SCS to compare and analyze the changes throughout the study.
Time frame: Crossover and follow-up visits 1 month, 3 months and 6 months
Paresthesia threshold
The difference between the randomization, crossover and follow-up visits (total of 6 evaluation) by asking patient to indicate the threshold at which he or she experiences paresthesia. The SCS transmitter allows several intensity levels which are tested before setting the SCS mode. Usually, the intensity level is tested from lowest and slowly increased until the patient experience paresthesia. Paresthesia threshold is different from patient to patient and it might change along time. Therefore, the intensity level marked by the SCS transmitter where the patient experienced the paresthesia will be recorded to evaluate the changes during the study period.
Time frame: Randomization, crossover and follow-up visits 1 month, 3 months and 6 months
Change in the overall SCS stimulation parameters
SCS stimulation parameters (active electrodes, frequency, pulse duration, amplitude and battery consumption) each visit after implantation. All parameters of SCS will be recorded in the same item as they are measured based on the SCS transmitter records and reflect the overall SCS status.
Time frame: From week 1 (randomization) to 6 months follow-up visit
Battery efficiency of the neuro-stimulator
The battery usage will be measured by frequencies to recharge the battery during the follow-up visits.
Time frame: Follow up visits 1 month, 3 months and 6 months
Adaptive Stim use
Acquire information on activity from the internal diary; amount of times that patients need to fit the ideal parameters themselves) during the follow-up visits
Time frame: Follow up visits 1 month, 3 months and 6 months
Measurement of adverse events
Any related adverse events throughout the whole study period (e.g. infection, hematoma, seroma, lead breakage, lead migration, SCS removal, etc).
Time frame: Six month from baseline screening
Plan to share: No
This study is terminated, as verified in Nov 2022. You cannot join it, but the record below documents what was studied.
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Seoul National University