Table 2.
Study, year, number of patients, type of study | Newer SCS mode | Follow-up time points after implantation | Outcomes assessed | Important results | Adverse effects of paresthesia-free SCS | Comments |
---|---|---|---|---|---|---|
Case reports/series | ||||||
Al-Kaisy et al.12 2015 (n = 15) CS (R) | HF-10 | 1, 3, and 6 months | NRS pain BPI PCS EQ-5D painDETECT |
At 6 months: NRS pain reduced by 59% BPI reduced by 45% PCS reduced by 75% EQ-5D increased by 101% Excellent or good satisfaction for 10/11 patients |
No adverse effects related to paresthesia-free SCS | 11/15 had successful trials but 3 of the 4 patients who had no benefit had CRPS of the foot; all 3 patients with CRPS of the hand responded |
Kriek et al.18 2015(n = 1) CR (R) | Burst | 24 months | NRS pain Medication intake Vasomotor and sudomotor symptoms ROM |
NRS pain decreased by 75% Lower medication intake No worsening in vasomotor and sudomotor symptoms or ROM |
— | Burst stimulation provides analgesia when tolerance develops to conventional SCS |
Reddy et al.19 2016 (n = 2) CS (P) | HF-10 | 0.5 days | VAS pain Discomfort Feedback from patients |
NRS pain reduced by 30%–50% Patients preference: HF |
0.5-day trial of HF-SCS during weeklong conventional trial; possibility of carryover effects | |
Smith et al.20 2015 (n = 1) CR (R) | HF (1.15 kHz) | 6 months | NRS pain QoL Medication intake Quality of sleep |
NRS pain reduced by 50% Reduction of medication intake |
— | Paresthesia-free (high-frequency) SCS mode used by patient to avoid intolerable paresthesias |
Tate21 2017(n = 1) CR (R) | HF-10 | 4 months | NRS pain QoL Vasomotor and sudomotor symptoms Anxiety ROM Medication intake |
100% pain relief with resolution of phantom limb pain, anxiety, and improved QoL Improvement in vasomotor and sudomotor symptoms ROM: improved gait Medication intake: opiate-free |
— | — |
Wille et al.13 2017(n = 3) CS (R) | HD | 1, 6, and 12 months after switch from conventional to HD SCS | NRS pain | Significant and progressive decrease (7.9 to 3.1) in NRS pain scores following implementation of HD mode for 12 months in 2 patients on HD for this duration One patient with CRPS requested reprogramming to conventional SCS due to preference to PB-SCS (although effect of PF-SCS) |
— | Possibility of a dose-related response between the amount of energy delivered to the spinal cord and clinical effect |
Abstracts | ||||||
Amirdelfan et al.22 2017 (n = 6) CS (R) | HF-10 | 4 to 15 months | VAS pain Medication usage Physical activity Vasomotor signs |
Decrease in VAS pain scores by 83% ± 3.0% and medication usage Improvement in activity and vasomotor signs |
— | All 6 patients responded |
Santarelli et al.23 2016 (n = 7) CS (P) | HF-10 | 3, 6, 9, and 12 months | VAS pain scores Medication usage Quality of life (SF-36) CES-D scores PGIC Functional status (6-min walking test or hand grip test) |
Follow-up ongoing at time of publication of abstract: long-term results not available for every patient At 3 months (n = 4): decrease in VAS pain scores (by 25%–100%) and in CES-D scores; improved ROM and PGIC scores At 12 months (n = 1): decrease in VAS pain scores to 0 at 12 months and decrease in CES-D scores by 66% with improvement in physical function |
— | 5 patients had positive trials and 1 patient had direct implant (due to diabetes) |
Smet and Van Buyten24 2016 (n = 1) CR (R) | HF-10 | 12 months | NRS pain ROM wrist Medication intake |
NRS pain reduced to 0/10 ROM in wrist improved Discontinuation of all analgesic medications |
— | — |
Gulve et al.25 2015 (n = 1) CR (R) | HF-10 | 18 months | NRS pain EQ-5D score Medications Functional improvement |
NRS pain: 80% reduction EQ-5D score increased from 0.2 to 0.8 Discontinuation of all analgesic medications and able to resume pre-injury activities |
No postural variation in analgesic effect and no sensory symptoms | |
Wohak26 2013 (n = 3) CS (R) | HF-10 | 4 to 8 months | NRS pain ROM Medication intake Vasomotor signs |
NRS pain and hyperalgesia decreased by 80%–100% ROM: improvement |
— | |
Randomized clinical trial | ||||||
Kriek et al.27 2017 (n = 29) RCT | Three groups: 500 Hz, 1200 Hz, Burst | At the end of 2 weeks with each of the fove modes At the end of 3 months with the preferred stimulation mode |
VAS for pain MPQ GPE Preference of type of stimulation |
VAS pain: All PF-SCS settings were equi-analgesic and significantly better with higher GPE scores than placebo VAS pain scores were lower with preferred stimulation 52% of patients preferred nonstandard stimulation |
No serious adverse effects | Various reasons for patients preferring particular modes: Amount of pain reduction Lack of paresthesia User-friendliness comfort Recharging time |
SCS = spinal cord stimulation; CS (R/P) = case series (retrospective/prospective); HF-10 = high-frequency stimulation at 10 kHz; NRS = numerical rating scale; BPI = Brief Pain Inventory; PCS = Pain Catastrophizing Scale; EQ-5D = EuroQol–five dimensions; CR = case report; ROM = range of motion; HF = high-frequency stimulation; VAS = visual analog scale; QoL = quality of life; HD = high-density stimulation; CRPS = complex regional pain syndrome; PB-SCS = paresthesia-based spinal cord stimulation; PF-SCS = parasthesia-free spinal cord stimulation; SF-36 = Short Form 36; CES-D = Center for Epidemiological Studies–Depression Scale; PGIC = Patient Global Impression of Change; RCT = randomized controlled trial.