Neurostimulation therapies—in particular motor cortex stimulation (MCS)—for chronic pain lack high-quality evidence. |
Commonly applied subjective score-based outcome measures are biased by intra- and inter-individual variability. |
The effects of burstMCS on pain levels and parameters of cardiovascular modulation remain largely unknown. |
Our preliminary findings indicate that burstMCS evokes pain relief and objectifiable changes in sympathetic and parasympathetic tone. |
Large-scale, sham-controlled trials are needed to clearly characterize these clinical effects on both pain and autonomic cardiovascular modulation. |
Introduction
Methods
fMRI-Guided BurstMCS Lead Implantation and Stimulation Protocol
Patient | Age (years) | Gender | Pain disorder | Medication | Previous treatment | Pre/post-burstMCS | Stimulation parameters | SAE |
---|---|---|---|---|---|---|---|---|
1 | 42 | F | TN V2/V3 right 5 years | Pregabalin NSAIR Opioids Dronabinol | MVD SRS TC Botox | VAS 9/10 vs. VAS 8/10 | 1.4–2.7 mA Bipolar Burst rate 40 Hz, intra-burst 500 Hz, pulse width 1 ms | – |
2 | 62 | F | TN V2/V3 right 10 years | Carbamazepine Mirtazapine | SRS TC Botox | VAS 10/10 vs. VAS 6/10 | 1.4–3.0 mA Bipolar Burst rate 40 Hz, intra-burst 500 Hz, pulse width 1 ms | – |
3 | 74 | M | PSP Hemibody right 10 years | Opioids Amitriptyline Antidepressants | – | VAS 10/10 vs. VAS 3/10 | 2.0–3.2 mA Bipolar Burst rate 40 Hz, intra-burst 500 Hz, pulse width 1 ms | – |
Protocol of Autonomic Testing and Data Analyses
Measurement of RR Intervals, Blood Pressure and Respiration at Rest and During Autonomic Challenge Maneuvers
Data Storage, Analyses of Time-Domain Parameters and Spectral Power of Autonomic Modulation
Autonomic Testing Protocol
Results
Patient Characteristics and Subjective Pain Scores (VAS) at Baseline and After 4 Months of BurstMCS
Autonomic Cardiovascular Modulation at Resting Conditions
First measurement | Second measurement | Controls | |
---|---|---|---|
Sympathetic parameter | |||
RRI-LFnu power | 0.76 | 0.62 | 0.43 |
SBP-LF power (mmHg2) | 17.6 | 20.4 | 12.4 |
Parasympathetic parameter | |||
RRI-HFnu power | 0.24 | 0.38 | 0.57 |
RRI-RMSSD (ms) | 7.7 | 14.7 | 35.4 |
Total autonomic parameter | |||
RRI-total power (ms2) | 129.3 | 406.2 | 877.2 |
RRI-SD (ms) | 11.6 | 18.5 | 32.3 |
RRI-CV | 1.9 | 3.7 | 3.9 |
Sympathovagal balance | |||
RRI-LF/HF ratio | 3.4 | 1.9 | 1.2 |
Baroreceptor reflex sensitivity (ms/mmHg) | 1.9 | 2.3 | 7.5 |
Autonomic Cardiovascular Modulation During Metronomic Deep Breathing
(A) | First measurement | Second measurement |
---|---|---|
E/I-ratio | ||
Patient 1 | 1.10* | 1.17 |
Patient 2 | 1.10 | 1.27 |
Patient 3 | 1.02* | 1.03* |
(B) | First measurement | Second measurement | ||
---|---|---|---|---|
RRI-RMSSD | RRI-CV | RRI-RMSSD | RRI-CV | |
Patient 1 | 8.8* | 2.0 | 15.6 | 2.6 |
Patient 2 | 9.2* | 2.7* | 25.2 | 4.9 |
Patient 3 | 5.1* | 0.9* | 3.2* | 0.6* |
Autonomic Cardiovascular Modulation During Active Standing
First Measurement | Second Measurement | |
---|---|---|
RRI-30/15 ratio | ||
Patient 1 | 1.15 | 1.16 |
Patient 2 | 0.98* | 0.98* |
Patient 3 | 1.01 | 1.02 |