Biophysics of Frequency-Dependent Variation in Paresthesia and Pain Relief during Spinal Cord Stimulation.

The neurophysiological effects of spinal cord stimulation (SCS) for chronic pain are poorly understood, resulting in inefficient failure-prone programming protocols and inadequate pain relief. Nonetheless, novel stimulation patterns are regularly introduced and adopted clinically. Traditionally, paresthetic sensation is considered necessary for pain relief, although novel paradigms provide analgesia without paresthesia. However, like pain relief, the neurophysiological underpinnings of SCS-induced paresthesia are unknown. Here, we paired biophysical modeling with clinical paresthesia thresholds (of both sexes) to investigate how stimulation frequency affects the neural response to SCS relevant to paresthesia and analgesia. Specifically, we modeled the dorsal column (DC) axonal response, dorsal column nucleus (DCN) synaptic transmission, conduction failure within DC fiber collaterals, and dorsal horn network output. Importantly, we found that high-frequency stimulation reduces DC fiber activation thresholds, which in turn accurately predicts clinical paresthesia perception thresholds. Furthermore, we show that high-frequency SCS produces asynchronous DC fiber spiking and ultimately asynchronous DCN output, offering a plausible biophysical basis for why high-frequency SCS is less comfortable and produces qualitatively different sensation than low-frequency stimulation. Finally, we demonstrate that the model dorsal horn network output is sensitive to SCS-inherent variations in spike timing, which could contribute to heterogeneous pain relief across patients. Importantly, we show that model DC fiber collaterals cannot reliably follow high-frequency stimulation, strongly affecting the network output and typically producing antinociceptive effects at high frequencies. Altogether, these findings clarify how SCS affects the nervous system and provide insight into the biophysics of paresthesia generation and pain relief.

Modulations in high-density EEG during the suppression of phantom-limb pain with neurostimulation in upper limb amputees.

Phantom limb pain (PLP) is a distressing and persistent sensation that occurs after the amputation of a limb. While medication-based treatments have limitations and adverse effects, neurostimulation is a promising alternative approach whose mechanism of action needs research, including electroencephalographic (EEG) recordings for the assessment of cortical manifestation of PLP relieving effects. Here we collected and analyzed high-density EEG data in 3 patients (P01, P02, and P03). Peripheral nerve stimulation suppressed PLP in P01 but was ineffective in P02. In contrast, transcutaneous electrical nerve stimulation was effective in P02. In P03, spinal cord stimulation was used to suppress PLP. Changes in EEG oscillatory components were analyzed using spectral analysis and Petrosian fractal dimension. With these methods, changes in EEG spatio-spectral components were found in the theta, alpha, and beta bands in all patients, with these effects being specific to each individual. The changes in the EEG patterns were found for both the periods when PLP level was stationary and the periods when PLP was gradually changing after neurostimulation was turned on or off. Overall, our findings align with the proposed roles of brain rhythms in thalamocortical dysrhythmia or disruption of cortical excitation and inhibition which has been linked to neuropathic pain. The individual differences in the observed effects could be related to the specifics of each patient's treatment and the unique spectral characteristics in each of them. These findings pave the way to the closed-loop systems for PLP management where neurostimulation parameters are adjusted based on EEG-derived markers.

Postsynaptic potentials of soleus motor neurons produced by transspinal stimulation: a human single-motor unit study.

Transspinal (or transcutaneous spinal cord) stimulation is a noninvasive, cost-effective, easily applied method with great potential as a therapeutic modality for recovering somatic and nonsomatic functions in upper motor neuron disorders. However, how transspinal stimulation affects motor neuron depolarization is poorly understood, limiting the development of effective transspinal stimulation protocols for rehabilitation. In this study, we characterized the responses of soleus α motor neurons to single-pulse transspinal stimulation using single-motor unit (SMU) discharges as a proxy given the 1:1 discharge activation between the motor neuron and the motor unit. Peristimulus time histogram, peristimulus frequencygram, and surface electromyography (sEMG) were used to characterize the postsynaptic potentials of soleus motor neurons. Transspinal stimulation produced short-latency excitatory postsynaptic potentials (EPSPs) followed by two distinct phases of inhibitory postsynaptic potentials (IPSPs) in most soleus motor neurons and only IPSPs in others. Transspinal stimulation generated double discharges at short interspike intervals in a few motor units. The short-latency EPSPs were likely mediated by muscle spindle group Ia and II afferents, and the IPSPs via excitation of group Ib afferents and recurrent collaterals of motor neurons leading to activation of diverse spinal inhibitory interneuronal circuits. Further studies are warranted to understand better how transspinal stimulation affects depolarization of α motor neurons over multiple spinal segments. This knowledge will be seminal for developing effective transspinal stimulation protocols in upper motor neuron lesions.NEW & NOTEWORTHY Transspinal stimulation produces distinct actions on soleus motor neurons: an early short-latency excitation followed by two inhibitions or only inhibition and doublets. These results show how transspinal stimulation affects depolarization of soleus α motor neurons in healthy humans.

Neurotechnology for Pain.

Neurotechnologies for treating pain rely on electrical stimulation of the central or peripheral nervous system to disrupt or block pain signaling and have been commercialized to treat a variety of pain conditions. While their adoption is accelerating, neurotechnologies are still frequently viewed as a last resort, after many other treatment options have been explored. We review the pain conditions commonly treated with electrical stimulation, as well as the specific neurotechnologies used for treating those conditions. We identify barriers to adoption, including a limited understanding of mechanisms of action, inconsistent efficacy across patients, and challenges related to selectivity of stimulation and off-target side effects. We describe design improvements that have recently been implemented, as well as some cutting-edge technologies that may address the limitations of existing neurotechnologies. Addressing these challenges will accelerate adoption and change neurotechnologies from last-line to first-line treatments for people living with chronic pain.

Spinal cord stimulation for postural abnormalities in Parkinson's disease: 1-year prospective pilot study.

BACKGROUND: Postural abnormalities (PA) are common in the advanced stages of Parkinson's disease (PD), but effective therapies are lacking. A few studies suggested that spinal cord stimulation (SCS) could be a potential therapy whereas its effect is still uncertain. We aimed to investigate whether SCS had potential for benefiting PD patients with PA. METHODS: T8-12 SCS was operated on six PD patients with PA and all patients were followed for one year. Evaluations were made before and after SCS. Moreover, three patients were tested separately with SCS on-state and off-state to confirm the efficacy of SCS. RESULTS: Improvements in lateral trunk flexion degree, anterior thoracolumbar flexion degree and motor function were found after SCS. The improvements diminished while SCS was turned off. CONCLUSIONS: Lower thoracic SCS may be effective for improving PA in PD patients, but further studies are needed to confirm this conclusion. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1900024326, Registered on 6th July 2019; https://www.chictr.org.cn/showproj.aspx?proj=40835 .

Interactions between arm and leg neuronal circuits following paired cervical and lumbosacral transspinal stimulation in healthy humans.

Transspinal (or transcutaneous spinal cord) stimulation is a promising noninvasive method that may strengthen the intrinsic spinal neural connectivity in neurological disorders. In this study we assessed the effects of cervical transspinal stimulation on the amplitude of leg transspinal evoked potentials (TEPs), and the effects of lumbosacral transspinal stimulation on the amplitude of arm TEPs. Control TEPs were recorded following transspinal stimulation with one cathode electrode placed either on Cervical 3 (21.3 ± 1.7 mA) or Thoracic 10 (23.6 ± 16.5 mA) vertebrae levels. Associated anodes were placed bilaterally on clavicles or iliac crests. Cervical transspinal conditioning stimulation produced short latency inhibition of TEPs recorded from left soleus (ranging from - 6.11 to -3.87% of control TEP at C-T intervals of -50, -25, -20, -15, -10, 15 ms), right semitendinosus (ranging from - 11.1 to -4.55% of control TEP at C-T intervals of -20, -15, 15 ms), and right vastus lateralis (ranging from - 13.3 to -8.44% of control TEP at C-T intervals of -20 and - 15 ms) (p < 0.05). Lumbosacral transspinal conditioning stimulation produced no significant effects on arm TEPs. We conclude that in the resting state, cervical transspinal stimulation affects the net motor output of leg motoneurons under the experimental conditions used in this study. Further investigations are warranted to determine whether this protocol may reactivate local spinal circuitry after stroke or spinal cord injury and may have a significant effect in synchronization of upper and lower limb muscle synergies during rhythmic activities like locomotion or cycling.

Distinguishing reflex from non-reflex responses elicited by transcutaneous spinal stimulation targeting the lumbosacral cord in healthy individuals.

Transcutaneous spinal stimulation (TSS) studies rely on the depolarization of afferent fibers to provide input to the spinal cord; however, this has not been routinely ascertained. Thus, we aimed to characterize the types of responses evoked by TSS and establish paired-pulse ratio cutoffs that distinguish posterior root reflexes, evoked by stimulation of afferent nerve fibers, from motor responses, evoked by stimulation of efferent nerve fibers. Twelve neurologically intact participants (six women) underwent unipolar TSS (cathode over T11-12 spinal processes, anode paraumbilically) while resting supine. In six participants, unipolar TSS was repeated 2-3 months later and also compared to a bipolar TSS configuration (cathode 2.5 cm below T11-12, anode 5 cm above cathode). EMG signals were recorded from 16 leg muscles. A paired-pulse paradigm was applied at interstimulus intervals (ISIs) of 25, 50, 100, 200, and 400 ms. Responses were categorized by three assessors into reflexes, motor responses, or their combination (mixed responses) based on the visual presence/absence of paired-pulse suppression across ISIs. The paired-pulse ratio that best discriminated between response types was derived for each ISI. These cutoffs were validated by repeating unipolar TSS 2-3 months later and with bipolar TSS. Unipolar TSS evoked only reflexes (90%) and mixed responses (10%), which were mainly recorded in the quadriceps muscles (25-42%). Paired-pulse ratios of 0.51 (25-ms ISI) and 0.47 (50-ms ISI) best distinguished reflexes from mixed responses (100% sensitivity, > 99.2% specificity). These cutoffs performed well in the repeated unipolar TSS session (100% sensitivity, > 89% specificity). Bipolar TSS exclusively elicited reflexes which were all correctly classified. These results can be utilized in future studies to ensure that the input to the spinal cord originates from the depolarization of large afferents. This knowledge can be applied to improve the design of future neurophysiological studies and increase the fidelity of neuromodulation interventions.

Enhancing spinal cord stimulation-induced pain inhibition by augmenting endogenous adenosine signalling after nerve injury in rats.

BACKGROUND: The mechanisms for spinal cord stimulation (SCS) to alleviate chronic pain are only partially known. We aimed to elucidate the roles of adenosine A1 and A3 receptors (A1R, A3R) in the inhibition of spinal nociceptive transmission by SCS, and further explored whether 2'-deoxycoformycin (dCF), an inhibitor of adenosine deaminase, can potentiate SCS-induced analgesia. METHODS: We used RNAscope and immunoblotting to examine the distributions of adora1 and adora3 expression, and levels of A1R and A3R proteins in the spinal cord of rats after tibial-spared nerve injury (SNI-t). Electrophysiology recording was conducted to examine how adenosine receptor antagonists, virus-mediated adora3 knockdown, and dCF affect SCS-induced inhibition of C-fibre-evoked spinal local field potential (C-LFP). RESULTS: Adora1 was predominantly expressed in neurones, whereas adora3 is highly expressed in microglial cells in the rat spinal cord. Spinal application of antagonists (100 µl) of A1R (8-cyclopentyl-1,3-dipropylxanthine [DPCPX], 50 µM) and A3R (MRS1523, 200 nM) augmented C-LFP in SNI-t rats (DPCPX: 1.39 [0.18] vs vehicle: 0.98 [0.05], P=0.046; MRS1523: 1.21 [0.07] vs vehicle: 0.91 [0.03], P=0.002). Both drugs also blocked inhibition of C-LFP by SCS. Conversely, dCF (0.1 mM) enhanced SCS-induced C-LFP inhibition (dCF: 0.60 [0.04] vs vehicle: 0.85 [0.02], P<0.001). In the behaviour study, dCF (100 nmol 15 µl-1, intrathecal) also enhanced inhibition of mechanical hypersensitivity by SCS in SNI-t rats. CONCLUSIONS: Spinal A1R and A3R signalling can exert tonic suppression and also contribute to SCS-induced inhibition of spinal nociceptive transmission after nerve injury. Inhibition of adenosine deaminase may represent a novel adjuvant pharmacotherapy to enhance SCS-induced analgesia.

Noninvasive spinal stimulation improves walking in chronic stroke survivors: a proof-of-concept case series.

BACKGROUND: After stroke, restoring safe, independent, and efficient walking is a top rehabilitation priority. However, in nearly 70% of stroke survivors asymmetrical walking patterns and reduced walking speed persist. This case series study aims to investigate the effectiveness of transcutaneous spinal cord stimulation (tSCS) in enhancing walking ability of persons with chronic stroke. METHODS: Eight participants with hemiparesis after a single, chronic stroke were enrolled. Each participant was assigned to either the Stim group (N = 4, gait training + tSCS) or Control group (N = 4, gait training alone). Each participant in the Stim group was matched to a participant in the Control group based on age, time since stroke, and self-selected gait speed. For the Stim group, tSCS was delivered during gait training via electrodes placed on the skin between the spinous processes of C5-C6, T11-T12, and L1-L2. Both groups received 24 sessions of gait training over 8 weeks with a physical therapist providing verbal cueing for improved gait symmetry. Gait speed (measured from 10 m walk test), endurance (measured from 6 min walk test), spatiotemporal gait symmetries (step length and swing time), as well as the neurophysiological outcomes (muscle synergy, resting motor thresholds via spinal motor evoked responses) were collected without tSCS at baseline, completion, and 3 month follow-up. RESULTS: All four Stim participants sustained spatiotemporal symmetry improvements at the 3 month follow-up (step length: 17.7%, swing time: 10.1%) compared to the Control group (step length: 1.1%, swing time 3.6%). Additionally, 3 of 4 Stim participants showed increased number of muscle synergies and/or lowered resting motor thresholds compared to the Control group. CONCLUSIONS: This study provides promising preliminary evidence that using tSCS as a therapeutic catalyst to gait training may increase the efficacy of gait rehabilitation in individuals with chronic stroke. Trial registration NCT03714282 (clinicaltrials.gov), registration date: 2018-10-18.

Effectiveness of combined dorsal root ganglion and spinal cord stimulation: a retrospective, single-centre case series for chronic focal neuropathic pain.

OBJECTIVE: This case series retrospectively reviewed the outcomes in patients implanted with combined, synchronous dorsal root ganglion stimulation (DRGS) and spinal cord stimulation (SCS) connected to a single implantable pulse generator (IPG) in a tertiary referral neuromodulation centre in the United Kingdom. METHODS: Twenty-six patients underwent a trial of DRGS+SCS for treating focal neuropathic pain between January 2016 and December 2019, with a follow-up in February 2022. A Transgrade approach was employed for DRGS. Patients were provided with 3 possible stimulation programs: DRGS-only, SCS-only, or DRGS+SCS. Patients were assessed for pain intensity, patients' global impression of change (PGIC), preferred lead(s) and complications. RESULTS: Twenty patients were successful and went on for full implantation. The most common diagnosis was Complex Regional Pain Syndrome. After an average of 3.1 years follow-up, 1 patient was lost to follow-up, and 2 were non-responders. Of the remaining 17 patients, 16 (94%) continued to report a PGIC of 7. The average pain intensity at Baseline was 8.5 on an NRS scale of 0-10. At the last follow-up, the average NRS reduction overall was 78.9% with no statistical difference between those preferring DRGS+SCS (n = 9), SCS-only (n = 3) and DRGS-only (n = 5). The combination of DRGS+SCS was preferred by 53% at the last follow-up. There were no serious neurological complications. CONCLUSIONS: This retrospective case series demonstrates the potential effectiveness of combined DRGS+SCS with sustained analgesia observed at an average follow-up of over 3 years. Implanting combined DRGS+SCS may provide programming flexibility and therapeutic alternatives.

Evaluation of thoracic sympathetic ganglion block as a predictor for response to ketamine infusion therapy and spinal cord stimulation in patients with chronic upper extremity pain.

OBJECTIVE: To investigate the predictive value of thoracic sympathetic ganglion block (TSGB) in response to ketamine infusion therapy (KIT) and spinal-cord stimulation (SCS) in patients with chronic upper-extremity pain including complex regional pain syndrome (CRPS). DESIGN: Retrospective. SETTING: Tertiary hospital single-center. SUBJECTS: Patients who underwent TSGB receiving KIT or SCS within a 3-year window. METHODS: Positive TSGB outcomes were defined as ≥ 2 0-10 Numerical Rating Scale (NRS) score reduction at 2 weeks post-procedure. Positive KIT and SCS outcomes were determined by ≥ 2 NRS score reduction at 2-4 weeks post-KIT and ≥4 NRS score reduction at 2-4 weeks post-SCS implantation, respectively. RESULTS: Among 207 patients who underwent TSGB, 38 received KIT and 34 underwent SCS implantation within 3 years post-TSGB; 33 patients receiving KIT and 32 patients receiving SCS were included. Among 33 patients who received KIT, 60.6% (n = 20) reported a ≥ 2 0-10 NRS pain-score reduction. Positive response to TSGB occurred in 70.0% (n = 14) KIT responders, significantly higher than that in 30.8% (n = 4) KIT non-responders. Multivariable analysis revealed a positive association between positive responses to TSGB and KIT (OR 7.004, 95% CI 1.26-39.02). Among 32 patients who underwent SCS implantation, 68.8% (n = 22) experienced short-term effectiveness. Positive response to TSGB was significantly higher in SCS responders (45.5%, n = 10) than in non-responders (0.0%). However, there were no associations between pain reduction post-TSGB and that post-KIT or post-SCS. CONCLUSIONS: A positive response to TSGB is a potential predictor for positive KIT and SCS outcomes among patients with chronic upper-extremity pain, including CRPS.

Combining Neuromodulation Strategies in Spinal Cord Injury Gait Rehabilitation: A Proof Of Concept, Randomized, Crossover Trial.

OBJECTIVES: To evaluate if acute intermittent hypoxia (AIH) coupled with transcutaneous spinal cord stimulation (tSCS) enhances task-specific training and leads to superior and more sustained gait improvements as compared with each of these strategies used in isolation in persons with chronic, incomplete spinal cord injury. DESIGN: Proof of concept, randomized crossover trial. SETTING: Outpatient, rehabilitation hospital. INTERVENTIONS: Ten participants completed 3 intervention arms: (1) AIH, tSCS, and gait training (AIH + tSCS); (2) tSCS plus gait training (SHAM AIH + tSCS); and (3) gait training alone (SHAM + SHAM). Each arm consisted of 5 consecutive days of intervention with a minimum of a 4-week washout between arms. The order of arms was randomized. The study took place from December 3, 2020, to January 4, 2023. MAIN OUTCOME MEASURES: 10-meter walk test at self-selected velocity (SSV) and fast velocity, 6-minute walk test, timed Up and Go (TUG) and secondary outcome measures included isometric ankle plantarflexion and dorsiflexion torque RESULTS: TUG improvements were 3.44 seconds (95% CI: 1.24-5.65) significantly greater in the AIH + tSCS arm than the SHAM AIH + tSCS arm at post-intervention (POST), and 3.31 seconds (95% CI: 1.03-5.58) greater than the SHAM + SHAM arm at 1-week follow up (1WK). SSV was 0.08 m/s (95% CI: 0.02-0.14) significantly greater following the AIH + tSCS arm than the SHAM AIH + tSCS at POST. Although not significant, the AIH + tSCS arm also demonstrated the greatest average improvements compared with the other 2 arms at POST and 1WK for the 6-minute walk test, fast velocity, and ankle plantarflexion torque. CONCLUSIONS: This pilot study is the first to demonstrate that combining these 3 neuromodulation strategies leads to superior improvements in the TUG and SSV for individuals with chronic incomplete spinal cord injury and warrants further investigation.

The effects of transcutaneous spinal cord stimulation delivered with and without high-frequency modulation on spinal and corticospinal excitability.

Transcutaneous spinal cord stimulation (TSCS) has been shown to improve motor recovery in people with spinal cord injury (SCI). Some groups deliver TSCS modulated with a kHz-frequency (TSCS-kHz); the intensity used for TSCS-kHz is usually set based on the motor threshold for TSCS, even though TSCS-kHz threshold is considerably higher than TSCS. As a result, TSCS-kHz interventions tend to be delivered at low intensities with respect to the motor threshold (~40%). In this study, we compared the effects of sub-threshold TSCS and TSCS-kHz, when delivered at similar intensity relative to their own motor threshold. Experiment I compared the after-effects of 20 min of sub-threshold (40% threshold) TSCS and TSCS-kHz on spinal and corticospinal excitability in able-bodied participants. Experiment II assessed the dose-response relationship of delivering short (10-pulse) trains of TSCS and TSCS-kHz at three different current intensities relative to the threshold (40%, 60%, and 80%). Experiment I found that 20 min of TSCS-kHz at a 40% threshold decreased posterior root reflex amplitude (p < 0.05), whereas TSCS did not. In experiment II, motor-evoked potential (MEP) amplitude increased following short trains of TSCS and TSCS-kHz of increasing intensity. MEP amplitude was significantly greater for TSCS-kHz compared with TSCS when delivered at 80% of the threshold (p < 0.05). These results suggest that TSCS and TSCS-kHz have different effects when delivered at similar intensity relative to their own threshold; both for immediate effects on corticospinal excitability and following prolonged stimulation on spinal excitability. These different effects may be utilized for optimal rehabilitation in people with SCI.

Inhibition of tibialis anterior spinal reflex circuits using frequency-specific neuromuscular electrical stimulation.

BACKGROUND: Neuromuscular electrical stimulation (NMES) can generate muscle contractions and elicit excitability of neural circuits. However, the optimal stimulation frequency for effective neuromodulation remains unclear. METHODS: Eleven able-bodied individuals participated in our study to examine the effects of: (1) low-frequency NMES at 25 Hz, (2) high-frequency NMES at 100 Hz; and (3) mixed-frequency NMES at 25 and 100 Hz switched every second. NMES was delivered to the right tibialis anterior (TA) muscle for 1 min in each condition. The order of interventions was pseudorandomized between participants with a washout of at least 15 min between conditions. Spinal reflexes were elicited using single-pulse transcutaneous spinal cord stimulation applied over the lumbar enlargement to evoke responses in multiple lower-limb muscles bilaterally and maximum motor responses (Mmax) were elicited in the TA muscle by stimulating the common peroneal nerve to assess fatigue at the baseline and immediately, 5, 10, and 15 min after each intervention. RESULTS: Our results showed that spinal reflexes were significantly inhibited immediately after the mixed-frequency NMES, and for at least 15 min in follow-up. Low-frequency NMES inhibited spinal reflexes 5 min after the intervention, and also persisted for at least 10 min. These effects were present only in the stimulated TA muscle, while other contralateral and ipsilateral muscles were unaffected. Mmax responses were not affected by any intervention. CONCLUSIONS: Our results indicate that even a short-duration (1 min) NMES intervention using low- and mixed-frequency NMES could inhibit spinal reflex excitability of the TA muscle without inducing fatigue.

Cervical Spinal Cord Stimulation: A Review.

PURPOSE OF REVIEW: This literature review critically examines existing studies on cervical spinal cord stimulation (cSCS) for the treatment of chronic pain. The objective is to evaluate the current evidence, identify knowledge gaps, and collate data to inform clinical decision-making and suggest future research avenues. The review covers indications, contraindications, surgical and anesthetic approaches, trials, efficacy, and complications of cSCS. RECENT FINDINGS: Recent advancements highlight the evolving role of cSCS in chronic pain management. New neuromodulation techniques involve optimal placement of leads based on the pain's innervation level, maximizing therapeutic outcomes. Contemporary studies underscore the broadening benefits of cSCS, including enhanced functional abilities and sleep quality. However, alongside these innovations come challenges; emerging data bring attention to complications such as hardware issues and infections. Significantly, modern research emphasizes the crucial role of accurate patient selection, factoring in prior therapy responses and comprehensive evaluations. cSCS emerges as a promising tool for chronic pain management, with benefits beyond mere pain relief. As surgical techniques, patient selection criteria, and postoperative care refine, the potential of cSCS expands to benefit a broader patient demographic. However, further comprehensive research is necessary to enhance its application, validate its role earlier in treatment, and ultimately ameliorate the lives of those with chronic pain.

A Review of Remote Monitoring in Neuromodulation for Chronic Pain Management.

PURPOSE OF REVIEW: Neuromodulation techniques have emerged as promising strategies for managing chronic pain. These techniques encompass various modalities of nerve stimulation, including Spinal Cord Stimulation (SCS), Dorsal Root Ganglion Stimulation (DRG-S), and Peripheral Nerve Stimulation (PNS). Studies consistently demonstrate significant improvements in pain intensity, quality of life, and reduced opioid usage among patients treated with these modalities. However, neuromodulation presents challenges, such as the need for frequent in-person follow-up visits to ensure proper functionality of the implanted device. Our review explored factors impacting compliance in current neuromodulation users and examined how remote monitoring can mitigate some of these challenges. We also discuss outcomes of recent studies related to remote monitoring of neuromodulation. RECENT FINDINGS: While remote monitoring capabilities for neuromodulation devices is an emerging development, there are promising results supporting its role in improving outcomes for chronic pain patients. Higher patient satisfaction, improved pain control, and reduced caretaker burdens have been observed with the use of remote monitoring. This review discusses the current challenges with neuromodulation therapy and highlights the role of remote monitoring. As the field continues to evolve, understanding the importance of remote monitoring for neuromodulation is crucial for optimizing pain management outcomes.

Complications of Spinal Cord Stimulators-A Comprehensive Review Article.

PURPOSE OF REVIEW: Spinal cord stimulation has been increasing in influence as an option to regulate pain, especially in the chronic pain patient population. However, even with the numerous changes made to this technology since its inception, it is still prone to various complications such as hardware issues, neurological injury/epidural hematoma, infections, and other biological concerns. The purpose of this article is to thoroughly review and evaluate literature pertaining to the complications associated with percutaneous spinal cord stimulation. RECENT FINDINGS: Lead migration is generally the most common complication of percutaneous spinal cord stimulation; however, recent utilization of various anchoring techniques has been discussed and experienced clinical success in decreasing the prevalence of lead migration and lead fractures. With newer high-frequency systems gaining traction to improve pain management and decrease complications as compared to traditional systems, rechargeable implantable pulse generators have been the preferred power source. However, recent findings may suggest that these rechargeable implantable pulse generators do not significantly increase battery life as much as was proposed. Intraoperative neuromonitoring has seen success in mitigating neurological injury postoperatively and may see more usage in the future through more testing. Though the occurrence of infection and biological complications, including dural puncture and skin erosion, has been less frequent over time, they should still be treated in accordance with established protocols. While many complications can arise following percutaneous spinal cord stimulator implantation, the procedure is less invasive than open implantation and has seen largely positive patient feedback. Hardware complications, the more common issues that can occur, rarely indicate a serious risk and can generally be remedied through reoperation. However, less common cases such as neurological injury, infections, and biological complications require prompt diagnosis to improve the condition of the patient and prevent significant damage.

Spinal Cord Stimulation Waveforms for the Treatment of Chronic Pain.

PURPOSE OF REVIEW: Since the advent of spinal cord stimulation (SCS), advances in technology have allowed for improvement and treatment of various conditions, especially chronic pain. Additionally, as the system has developed, the ability to provide different stimulation waveforms for patients to treat different conditions has improved. The purpose and objective of the paper is to discuss basics of waveforms and present the most up-to-date literature and research studies on the different types of waveforms that currently exist. During our literature search, we came across over sixty articles that discuss the various waveforms we intend to evaluate. RECENT FINDINGS: There are several publications on several waveforms used in clinical practice, but to our knowledge, this is the only educational document teaching on waveforms which provides essential knowledge. There is a gap of knowledge related to understanding wave forms and how they work.

Cervical Spinal Cord Stimulation for Failed Neck Surgery Syndrome.

PURPOSE OF REVIEW: Cervical spine pain with or without radicular symptoms is a common condition leading to high utilization of the healthcare system with over 10 million medical visits per year. Many patients undergo surgical interventions and unfortunately are still left with neck and upper extremity pain, sometimes referred to as "Failed Neck Surgery Syndrome." When these options fail, cervical spinal cord stimulation can be a useful tool to decrease pain and suffering as well as reduce prescription medication use. RECENT FINDINGS: Spinal cord stimulation is a well-established therapy for chronic back and leg pain and is becoming more popular for neck and upper extremity pain. Recent studies have explored cervical spinal cord stimulation with successful outcomes regarding improved pain scores, functional outcomes, and reduction of prescription medication use. Continued research into cervical spinal cord stimulation is essential for maximizing its therapeutic potential for patients with chronic neck and upper extremity pain. This review highlights the importance of cervical spinal cord stimulation as an option for patients with failed neck surgery syndrome.

Diabetic Neuropathy: A Guide to Pain Management.

PURPOSE OF REVIEW: Diabetic neuropathy is a common complication of diabetes mellitus (DM) and can affect up to 50% of DM patients during their lifetime. Patients typically present with numbness, tingling, pain, and loss of sensation in the extremities. Since there is no treatment targeting the underlying mechanism of neuropathy, strategies focus on preventative care and pain management. RECENT FINDINGS: Up to 69% of patients with diabetic neuropathy receive pharmacological treatment for neuropathic pain. The United States Food and Drug Administration (FDA) confirmed four drugs for painful diabetic neuropathy (PDN): pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch. Nonpharmacological treatments such as spinal cord stimulation (SCS) and transcutaneous electrical nerve stimulation (TENS) both show promise in reducing pain in DM patients. Despite the high burden associated with PDN, effective management remains challenging. This update covers the background and management of diabetic neuropathy, including its epidemiology, pathogenesis, preventative care, and current therapeutic strategies.