From Prediction to Monitoring: Toward a Translational Framework of Biomarkers in Spinal Cord Stimulation
Abstract
1. Introduction
2. Materials and Methods
2.1. Search Strategy
- Human studies.
- Articles published in English.
- Studies reporting original data.
2.2. Eligibility Criteria
- Investigated patients undergoing spinal cord stimulation for chronic pain conditions (e.g., PSPS-T2, CRPS, neuropathic pain).
- Evaluated at least one biomarker, defined as a measurable physiological, imaging, or molecular parameter.
- Reported an association between the biomarker and the following:
- ○
- Treatment response;
- ○
- Clinical outcomes (e.g., pain intensity, disability);
- ○
- Or biological effects of SCS.
- Studies without objective biomarkers (e.g., purely clinical or patient-reported predictors without biological measures).
- Technical or engineering studies without clinical correlation.
- Review articles, editorials, and guidelines.
- Case reports.
- Studies not specifically addressing spinal cord stimulation.
2.3. Study Selection
- Title and abstract screening, excluding clearly irrelevant studies.
- Full-text assessment of potentially eligible articles.
2.4. Data Extraction
- Study design.
- Population characteristics and sample size.
- Type of biomarker (neuroimaging, electrophysiological, molecular, physiological).
- Specific biomarker parameters.
- Timing of measurement (pre-implant, intraoperative, post-implant, longitudinal).
- Clinical outcomes.
- Key quantitative findings (e.g., AUC, accuracy, correlations).
- Study limitations.
| Reference | First Author, Year | Study Design | Population (N, Condition) | Biomarker Type | Specific Biomarker | Timing (Baseline vs. Post-SCS) | Outcome | Key Findings (Quantitative If Available) | Classification (Predictive/Monitoring/Mechanistic) | Level of Evidence |
|---|---|---|---|---|---|---|---|---|---|---|
| [16] | De Andrés, 2021 | Prospective longitudinal study | N = 16, FBSS | Genomic/Protein (PBMCs) | PENK, CB1, CB2, IL-1 b gene/protein expression | Baseline vs. 24 h, 5 d, 15 d, 2 m | NRS, PD-Q, ODI, SF-12 | PENK significantly increased (p = 0.000; median increase 3.22). PENK changes correlated positively with VAS and negatively with SF-12 MCS. IL-1 b correlated negatively with PD-Q. | Mechanistic/Monitoring | Level II |
| [14] | Fabregat-Cid, 2023 | Prospective case–control study | N = 30 PSPS-2, N = 14 HC | Serum Proteomics | 462 proteins (Mass Spectrometry) | Baseline vs. 2 w, 2 m, 6 m, 12 m | NRS, ODI, PD-Q, HADS, SF-12 | Responders showed downregulation of immune/inflammatory proteins and upregulation of synaptic/metabolic proteins. 83 proteins remained significant throughout (p ≤ 0.05). | Mechanistic (with potential predictive value) | Level II |
| [15] | Fabregat-Cid, 2024 | Prospective GWAS | N = 30 PSPS-2, N = 15 HC | Genomic (mRNA Microarray) | mRNA expression profiling (microarray) | Baseline vs. 2 w, 2 m | NRS, PD-Q, ODI, HADS, SF-12 | 11 genes downregulated in PSPS-2 vs. HC. 2 genes (FUT6, TNS2-AS1) downregulated post-SCS response. Evidence of enhanced inflammation/proliferative response in PSPS-2. | Mechanistic | Level II |
| [21] | Gopal, 2025 | Prospective cohort/ML validation | N = 20, Chronic pain (PSPS, CRPS, CLBP) | Electrophysiological (EEG) | Intraoperative EEG features (including alpha/theta ratio) | Intraoperative Baseline vs. Tonic vs. HD | ≥50% NRS reduction at 3 m | ML model predicted responders with 88.2% accuracy. Alpha-theta ratio differed by region (p = 0.019). Baseline FP1-FP2 ratio correlated with NRS (r = −0.800, p = 0.041). | Predictive | Level II |
| [12] | Goudman, 2021 | Prospective comparative study | N = 22, FBSS | Physiological (Autonomic) | HRV indices (IBI, HR, SDNN, RMSSD, LF, HF) via ECG | Baseline (12 h off) vs. 40 min post-SCS | Autonomic balance/Device reliability | Significant increase in IBI (p = 0.001) and absolute HF power (p = 0.01); decrease in HR (p = 0.001) and normalized LF (p = 0.02) during SCS. Good agreement between measurement methods (r ≥ 0.82). | Monitoring/Mechanistic | Level II-2 |
| [22] | Kinfe, 2017 | Prospective feasibility cohort | N = 12, FBSS | Plasma Cytokines | IL-10, HMGB1, IL-1 b, TNF-a | Baseline vs. 3 months (Burst SCS) | VAS, PSQI, BDI | IL-10 significantly elevated post-SCS (43.16 vs. 12.54 pg/mL; p = 0.03). Pre-burst IL-10 correlated with VAS-B (r = −0.66). Post-burst IL-10 correlated with PSQI (r = −0.66). | Mechanistic/Monitoring | Level II |
| [13] | Kogias, 2025 | Prospective cohort study | N = 16 PSPS-T2, N = 16 HC | Cytometry/Cytokine Multiplex | Plasma cytokines; T-lymphocyte subsets (TH17, NKT, TEMRA) | Baseline vs. 7–10 days (10 kHz) | NRS, DASS42, PCS, NPQ | Significant reduction in IL-1 b, IL-6, IL-8, IL-10, IL-12, and IFN-g. Reduction in TH17 and NKT abundance correlated with pain relief (p < 0.05). | Mechanistic/Monitoring | Level II |
| [10] | Poply, 2023 | Randomized blinded crossover trial | N = 14, FBSS (Intractable lumbar neuropathic pain) | Metabolic (Imaging) | 18F-FDG PET-CT (SUVmax) | Baseline vs. 4 weeks (40 Hz, 4 kHz, 10 kHz) | NRS, ODI, EQ-5D-5L, PGIC | Significant SUVmax reduction at 40 Hz (p = 0.002) and 4 kHz (p = 0.001). Thalamic metabolic reduction reached 59.5%. 10 kHz PET uptake correlated with NRS-L (p = 0.011). | Mechanistic | Level II |
| [23] | Telkes, 2020 | Prospective intraoperative study | N = 9, FBSS or CLBP | Electrophysiological (EEG) | Spectral EEG (Alpha power, Peak power ratio) | Intraoperative Baseline vs. Tonic vs. 10 kHz | NRS, ODI at 3 months | 10 kHz SCS increased S1 relative alpha power (p = 0.005) and shifted peak from theta to alpha. Alpha/theta ratio in S1/Frontal regions strong correlation with ODI change (Spearman r = 1.00, p = 0.017; small sample). | Monitoring/Mechanistic | Level II |
| [11] | Ueno, 2025 | Prospective clinical investigation | N = 29, Chronic pain (PSPS-2, CRPS, PHN) | Neurological (Imaging) | rs-fMRI (Functional Connectivity) | Baseline (pre-SCS trial) | ≥50% NRS reduction (Trial responsiveness) | Mid ACC-precuneus/PCC connectivity was significantly lower in responders. Area under the curve (AUC) = 0.814, sensitivity 71%, specificity 87% (p < 0.001). | Predictive | Level II-2 |
| [24] | Witjes, 2025 | Case–control/ML classification | N = 75 (25 chronic pain, 25 SCS, 25 HC) | Neurological (MEG) | MEG spectral features (Theta, Alpha, Beta, Low-gamma) | Post-SCS (Tonic, Burst, Sham) | Pain classification/Treatment effect | Theta/alpha power ratio classified chronic pain with 76% accuracy (AUC 0.80). Poor correlation (rho = 0.12) between model output and SCS pain scores. | Mechanistic (diagnostic classification) | Level II-2 |
2.5. Biomarker Classification
- Predictive biomarkers: measured before or during implantation and associated with subsequent treatment response.
- Monitoring biomarkers: reflecting dynamic changes during or after SCS.
- Mechanistic biomarkers: providing insight into biological processes without demonstrated clinical predictive utility.
2.6. Evidence Appraisal
- Sample size.
- Study design (prospective vs. retrospective).
- Presence of quantitative predictive metrics (e.g., AUC, accuracy).
- External validation.
3. Predictive Biomarkers
3.1. Electrophysiological Biomarkers
3.2. Neuroimaging Biomarkers
3.3. Other Biomarker Domains
4. Monitoring Biomarkers
4.1. Autonomic Biomarkers
4.2. Neuroimaging Biomarkers
4.3. Immunological and Molecular Biomarkers
5. Translational Integration
6. Current Limitations
7. Future Directions
8. Conclusions
Funding
Data Availability Statement
Conflicts of Interest
References
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Fabregat-Cid, G.; Escrivá-Matoses, N.; De Andrés, J. From Prediction to Monitoring: Toward a Translational Framework of Biomarkers in Spinal Cord Stimulation. Biomedicines 2026, 14, 1307. https://doi.org/10.3390/biomedicines14061307
Fabregat-Cid G, Escrivá-Matoses N, De Andrés J. From Prediction to Monitoring: Toward a Translational Framework of Biomarkers in Spinal Cord Stimulation. Biomedicines. 2026; 14(6):1307. https://doi.org/10.3390/biomedicines14061307
Chicago/Turabian StyleFabregat-Cid, Gustavo, Natalia Escrivá-Matoses, and José De Andrés. 2026. "From Prediction to Monitoring: Toward a Translational Framework of Biomarkers in Spinal Cord Stimulation" Biomedicines 14, no. 6: 1307. https://doi.org/10.3390/biomedicines14061307
APA StyleFabregat-Cid, G., Escrivá-Matoses, N., & De Andrés, J. (2026). From Prediction to Monitoring: Toward a Translational Framework of Biomarkers in Spinal Cord Stimulation. Biomedicines, 14(6), 1307. https://doi.org/10.3390/biomedicines14061307
