EEG Monitoring Is Feasible and Reliable during Simultaneous Transcutaneous Electrical Spinal Cord Stimulation

Transcutaneous electrical spinal cord stimulation (tSCS) is a non-invasive neuromodulatory technique that has in recent years been linked to improved volitional limb control in spinal-cord injured individuals. Although the technique is growing in popularity there is still uncertainty regarding the neural mechanisms underpinning sensory and motor recovery. Brain monitoring techniques such as electroencephalography (EEG) may provide further insights to the changes in coritcospinal excitability that have already been demonstrated using other techniques. It is unknown, however, whether intelligible EEG can be extracted while tSCS is being applied, owing to substantial high-amplitude artifacts associated with stimulation-based therapies. Here, for the first time, we characterise the artifacts that manifest in EEG when recorded simultaneously with tSCS. We recorded multi-channel EEG from 21 healthy volunteers as they took part in a resting state and movement task across two sessions: One with tSCS delivered to the cervical region of the neck, and one without tSCS. An offline analysis in the time and frequency domain showed that tSCS manifested as narrow, high-amplitude peaks with a spectral density contained at the stimulation frequency. We quantified the altered signals with descriptive statistics—kurtosis, root-mean-square, complexity, and zero crossings—and applied artifact-suppression techniques—superposition of moving averages, adaptive, median, and notch filtering—to explore whether the effects of tSCS could be suppressed. We found that the superposition of moving averages filter was the most successful technique at returning contaminated EEG to levels statistically similar to that of normal EEG. In the frequency domain, however, notch filtering was more effective at reducing the spectral power contribution of stimulation from frontal and central electrodes. An adaptive filter was more appropriate for channels closer to the stimulation site. Lastly, we found that tSCS posed no detriment the binary classification of upper-limb movements from sensorimotor rhythms, and that adaptive filtering resulted in poorer classification performance. Overall, we showed that, depending on the analysis, EEG monitoring during transcutaneous electrical spinal cord stimulation is feasible. This study supports future investigations using EEG to study the activity of the sensorimotor cortex during tSCS, and potentially paves the way to brain–computer interfaces operating in the presence of spinal stimulation.

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Burst Spinal Cord Stimulation for the Treatment of Cervical Dystonia with Intractable Pain: A Pilot Study

Brain Sciences ◽

10.3390/brainsci10110827 ◽

2020 ◽

Vol 10 (11) ◽

pp. 827

Author(s):

Takeshi Shimizu ◽

Tomoyuki Maruo ◽

Shimpei Miura ◽

Yuki Kimoto ◽

Yukitaka Ushio ◽

...

Keyword(s):

Spinal Cord ◽

Pilot Study ◽

Clinical Efficacy ◽

Cervical Dystonia ◽

Spinal Cord Stimulation ◽

Motor Symptom ◽

Cervical Region ◽

Intractable Pain ◽

Motor Symptoms

Pain is the most common and disabling non-motor symptom in patients with cervical dystonia. Here, we report four patients with painful cervical dystonia in whom burst spinal cord stimulation (SCS) in the cervical region produced sustained and significant improvements in both dystonic pain and motor symptoms. Further studies need to be performed to investigate the clinical efficacy of burst SCS for patients with cervical dystonia.

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Rate of perioperative neurological complications after surgery for cervical spinal cord stimulation

Journal of Neurosurgery Spine ◽

10.3171/2015.10.spine15670 ◽

2016 ◽

Vol 25 (1) ◽

pp. 31-38 ◽

Cited By ~ 7

Author(s):

Andrew K. Chan ◽

Ethan A. Winkler ◽

Line Jacques

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Spinal Cord Stimulation ◽

Cervical Spinal Cord ◽

Perioperative Complications ◽

Univariate Analysis ◽

Injury Rate ◽

The United States ◽

Cervical Region ◽

Cord Injury

OBJECTIVE Cervical spinal cord stimulation (cSCS) is used to treat pain of the cervical region and upper extremities. Case reports and small series have shown a relatively low risk of complication after cSCS, with only a single reported case of perioperative spinal cord injury in the literature. Catastrophic cSCS-associated spinal cord injury remains a concern as a result of underreporting. To aid in preoperative counseling, it is necessary to establish a minimum rate of spinal cord injury and surgical complication following cSCS. METHODS The Nationwide Inpatient Sample (NIS) is a stratified sample of 20% of all patient discharges from nonfederal hospitals in the United States. The authors identified discharges with a primary procedure code for spinal cord stimulation (ICD-9 03.93) associated with a primary diagnosis of cervical pathology from 2002 to 2011. They then analyzed short-term safety outcomes including the presence of spinal cord injury and neurological, medical, and general perioperative complications and compared outcomes using univariate analysis. RESULTS Between 2002 and 2011, there were 2053 discharges for cSCS. The spinal cord injury rate was 0.5%. The rates of any neurological, medical, and general perioperative complications were 1.1%, 1.4%, and 11.7%, respectively. There were no deaths. CONCLUSIONS In the largest series of cSCS, the risk of spinal cord injury was higher than previously reported (0.5%). Nonetheless, this procedure remains relatively safe, and physicians may use these data to corroborate the safety of cSCS in an appropriately selected patient population. This may become a key treatment option in an increasingly opioid-dependent, aging population.

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Cardiovascular Effects of Spinal Cord Stimulation in Hypertensive Patients

January 2018 - Pain Physician ◽

10.36076/ppj.2011/14/1 ◽

2011 ◽

Vol 1;14 (1;1) ◽

pp. 1-14

Author(s):

Dr. David Schultz

Keyword(s):

Spinal Cord ◽

Heart Rate ◽

Heart Rate Variability ◽

Frequency Domain ◽

Spinal Cord Stimulation ◽

Cold Pressor Test ◽

Cold Pressor ◽

Thoracic Spinal Cord ◽

Pressor Test ◽

Placebo Phase

Background: Several animal and clinical studies have shown that thoracic spinal cord stimulation (SCS) may decrease mean arterial pressure (MAP). A previous study in normotensive participants demonstrated a small reduction in MAP during SCS at the T5-T6 spinal level. It has also been demonstrated that chronic SCS at the subthreshold stimulation level significantly improved angina attacks and 6 minute hall walk distance in drug refractory angina patients. Objectives: To determine if thoracic SCS at 2 different stimulation strengths would decrease blood pressure (BP) and heart rate (HR) during baseline conditions and during activation of the sympathetic system by the cold pressor test (CPT). Methods: Six hypertensive participants and 9 normotensive participants were evaluated. The SCS leads were implanted under sedation (midazolam and fentanyl) 3 days prior to the study. The SCS device was not implanted at the time of lead implantation; the exteriorized leads were connected to an external programmer at the time of the study. MAP was measured at the finger using beat-to-beat photoplethysmographic recordings at rest and during CPT with a Finometer (Model 1, Finapress Medical Systems, Amsterdam, The Netherlands). SCS at threshold (100%, SCS100) and subthreshold (80%, SCS80) intensities were randomly performed in the T5-T6 region of the spinal cord during normal conditions as well as during CPT. Each participant had 3 CPTs with the placebo (control, no SCS) CPT always performed first. CPT was performed by immersing the right hand into ice water for 90 seconds. Thirty seconds of beat-to-beat data prior to starting each CPT (baseline) was analyzed. During the 90 second CPT, the median values of the last 30 seconds of data were used for analysis. Heart rate variability (HRV) during baseline and SCS was computed using Kubios HRV Version 2.0 software (University of Kuopio, Kuopio, Finland). Since the median values of HR, MAP and their changes did not follow a normal distribution, groups were compared with a non-parametric Friedman’s or Wilcoxon’s signed rank test. The HRV data were normally distributed and a repeated measures analysis of variance (ANOVA) was used. Results: SCS did not significantly alter MAP or HR at baseline nor did it appear to blunt changes in MAP or HR in response to CPT. In the normotensive group, MAP was significantly elevated by a median value of 16 mmHg (P<0.001) during the placebo phase, and by 18 and 10.5 mmHg during the SCS80 and SCS100 phases, respectively. In the hypertensive group, an enhanced response to the CPT was observed. In these participants, the MAP was significantly elevated by a median value of 26.8 mmHg (P<0.001) during the placebo phase, and by 20 and 17 mmHg during the SCS80 and SCS100 phases, respectively. There was a non-significant trend for the CPT-induced increase in BP to be attenuated during SCS80. HRV tended to decrease in both the time and frequency domain in hypertensive participants, although this decrease was not statistically significant. Limitations: This was a pilot study including a limited number of participants Conclusions: Acute SCS at the T5-T6 region did not significantly alter MAP or HR compared to baseline (no SCS) in participants without sedation, supporting our previous findings in sedated patients. Hypertensive participants had a heightened response to transient cold stress, consistent with the literature. The observation of the tendency for a reduction in HRV in both the time and frequency domain in hypertensive participants is also consistent with the literature. In contrast to acute SCS, the hemodynamic effects of chronic SCS should be explored in the future. Key words: Spinal cord stimulation, hemodynamics, cold pressor test, heart rate variability, hypertension

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