A female patient in her 40s suffering from refractory axial thoracic pain achieved substantial pain relief and restored daily physical functioning following treatment with evoked compound action potential-controlled closed-loop spinal cord stimulation, according to a case report published in Clinical Case Reports. The patient presented with a body mass index of 32.1 kg/m2 and severe, constant, and debilitating pain localized to the T6 to T9 dermatomal distribution, rating her baseline discomfort at an 8 out of 10 on the numeric rating scale. Her condition had proven completely unresponsive to extensive previous interventions, including physical therapy, pharmacologic therapies, spinal injections, nerve blocks, and ablations, leaving her functionally restricted to approximately three hours of sleep per night and a standing and walking tolerance of only twenty minutes.
The patient was ultimately diagnosed with idiopathic neuropathic thoracic spine pain, a condition that remains clinically challenging and understudied despite its significant global health burden. The authors noted that thoracic pain accounts for approximately 5 percent of patient referrals to outpatient pain clinics, making it far less common than cervical or lumbosacral pain syndromes. According to the research cited in the report, thoracic spine pain frequently stems from occupational overload, sedentary behaviors, poor posture, physical inactivity, and degenerative joint pathology, with established associations including younger age, female sex, higher body mass index, elevated anxiety scores, cardiovascular disease, and prolonged sitting or reclining postures.
Traditional clinical approaches to thoracic spine pain management rely on pharmacologic agents, physical therapy, and interventional procedures, but these strategies carry notable therapeutic limitations. Opioid analgesics are frequently prescribed for severe presentations, yet their clinical utility is bounded by adverse effects, diversion risks, and hypodopaminergic-induced hyperalgesia, a physiological phenomenon where dopamine depletion increases pain sensitivity over time. Because of these challenges, neuromodulation approaches have attracted interest as safe, minimally invasive, and reversible alternatives for patients with chronic thoracic spine discomfort that fails conservative care.
Conventional spinal cord stimulation systems have previously demonstrated efficacy for chronic thoracic pain, but they operate through an open-loop mechanism delivering fixed stimulation parameters. Because open-loop systems do not adjust for physiological shifts—such as changes in the distance between implanted electrodes and neural tissue during postural adjustments—patients can experience fluctuating neural activation that results in episodes of uncomfortable overstimulation or ineffective understimulation. To overcome these limitations, closed-loop neuromodulation systems measure dorsal column fiber responses in the form of evoked compound action potentials, using these physiological feedback signals to automatically adjust stimulation intensity and preserve steady neural recruitment despite body movement.
Before beginning the intervention, the patient identified three explicit functional goals: increasing standing tolerance beyond twenty minutes, extending walking endurance beyond twenty minutes, and achieving more than three hours of continuous sleep each night. Because previous therapies had failed to provide meaningful relief, she elected to proceed with a trial utilizing a Saluda Medical closed-loop spinal cord stimulation system designed to maintain stable neural engagement during daily physical activities and prevent postural overstimulation.
During the procedure, clinicians placed a single 12-electrode percutaneous lead targeting the superior articular facet of the T5 vertebra, positioning the contacts one to three anatomical segments cephalad to the patient’s reported pain distribution for optimal dermatomal coverage. Programming utilized a 12-electrode configuration with contact spacing designed for preferential activation across the top three contacts arranged in a guarded cathode distribution of positive, negative, and positive polarity to maximize electrical field distribution. The initial stimulation parameters were configured with a pulse width of 250 microseconds, a stimulation frequency of 40 Hz, and a maximum current output of 13 mA, with patient sensitivity detected at 40 microvolts per milliampere, an evoked compound action potential target maximum of 60 microvolts, and an adjustment increment of 1 microvolt.
Over the course of the one-week trial period, the closed-loop system recorded 100 percent device utilization and executed approximately 24 million automated stimulation adjustments in response to physiological feedback. The system maintained high dose accuracy throughout the trial, remaining consistently within plus or minus 5 microvolts of the targeted neural response. Data from the trial confirmed highly stable neural activation during everyday activities, without the fluctuating overstimulation or loss of therapeutic effect typical of fixed-parameter open-loop devices.
At the conclusion of the trial, the patient successfully met all three predefined clinical goals, demonstrating marked improvements across pain intensity and physical function. Her self-reported pain score dropped from an initial 8 out of 10 to a 2 out of 10 on the numeric rating scale, while her standing and walking tolerance expanded from twenty minutes to six hours. Her sleep duration also doubled, increasing from three hours to six hours per night, prompting the patient to proceed with permanent implantation of the spinal cord stimulator lead across the T5 vertebral body under fluoroscopic guidance.
The investigators emphasized that closed-loop evoked compound action potential-controlled neuromodulation operates by continuously measuring dorsal column activation and dynamically adapting energy output to compensate for posture changes, activity levels, and cerebrospinal fluid dynamics. In addition to delivering sustained pain reduction without requiring increases in stimulation output, the automated system reduced the clinical burden of frequent manual reprogramming sessions that often burden patients and healthcare providers managing conventional open-loop systems. The stable relief achieved without escalating output further suggested that closed-loop regulation might help mitigate therapy tolerance or neural habituation.
The report situated these findings within broader neuromodulation research, noting prior applications of thoracic stimulation such as work by Benedetti and colleagues treating pain following incomplete cervical spinal cord injury. Furthermore, earlier observational studies in chronic back pain demonstrated sustained long-term efficacy with closed-loop systems, documenting that 81.4 percent of patients maintained at least 50 percent pain relief and 53.5 percent achieved at least 80 percent relief at twelve months, alongside device utilization of 84.9 percent. Another cited trial identified statistically significant pain reductions following closed-loop therapy, recording an 18.95 percent reduction in pain severity at three months (p = 0.01, 95% confidence interval -3.1 to -0.5), while multimodal conservative therapies such as education, manual therapy, and exercise remain recommended adjuncts alongside stimulation.
Despite the successful outcome observed in this patient, the authors emphasized important limitations inherent to single-patient case reports and stressed that findings cannot be generalized across broader populations without further investigation. They concluded that larger prospective clinical studies with expanded cohorts are essential to rigorously establish the therapeutic efficacy and safety of closed-loop spinal cord stimulation for axial thoracic pain, and to determine whether specific thoracic spinal imaging characteristics can help clinicians identify patients most likely to benefit from this physiologically adaptive intervention.
The decision to select a single twelve-contact lead rested directly on the patient’s localized midline axial presentation. Intraoperative testing confirmed the clinical utility of this anatomical approach at the T5 vertebral level, evaluating electrical and neural responses in real time. Clinicians established that the single percutaneous lead produced normal electrical impedances alongside appropriate evoked compound action potential signals. This intraoperative evaluation verified satisfactory dermatomal coverage and effective neural engagement across the target spinal cord region, demonstrating that a single midline lead was sufficient to cover the patient’s painful distribution without requiring additional surgical lead arrays.
Although closed-loop technology guided by evoked compound action potentials has gained clinical exploration in lumbar conditions, its role in axial thoracic pain addresses an area that remains notably understudied in neuromodulation research. Conventional open-loop spinal cord stimulation systems administer fixed voltage or current parameters that rely primarily on subjective patient feedback. Under open-loop delivery, regular physiological variations, such as changes in body posture, physical movement, and cerebrospinal fluid dynamics, alter the physical distance separating the implanted electrodes from adjacent neural tissue. These shifting anatomical distances can produce inconsistent dorsal column recruitment, resulting in episodes where patients experience either inadequate therapeutic stimulation or painful overstimulation.
By directly monitoring the neural response of dorsal column fibers produced by stimulation pulses, closed-loop systems use these measurable evoked signals as an active physiological control mechanism. The automated algorithm continuously increases or decreases energy output to stabilize neural recruitment, effectively diminishing variability despite postural fluctuations. This dynamic capability also relieves substantial clinical burdens. In open-loop protocols, patients frequently require repeated clinician-led reprogramming sessions to readjust parameters after positional shifts, a process that increases overall healthcare utilization and can heighten patient frustration. The continuous physiological adjustments in closed-loop systems reduce this reprogramming necessity while minimizing patient awareness of stimulation changes. Furthermore, achieving durable pain control without escalating stimulation energy output suggests that closed-loop regulation might help counteract the onset of neural tolerance or habituation.
Beyond technological advances in neuromodulation, long-standing conservative strategies remain central to comprehensive pain management frameworks. Physical therapy and psychotherapy have been utilized for decades, with physiotherapists emphasizing that effective care requires a multimodal program combining patient education, manual therapy, and targeted therapeutic exercise. Medical literature confirms that these conventional approaches deliver positive clinical benefits for individuals with chronic pain and are broadly recommended across clinical practice. Within this multimodal care model, conservative techniques can serve as valuable adjuncts alongside spinal cord stimulation to provide quick pain relief to the patient. As neuromodulation continues to evolve, the authors note that prospective clinical trials involving larger patient cohorts are needed to further evaluate closed-loop systems in thoracic pain and to determine whether specific thoracic spinal imaging characteristics can help clinicians identify which patients are most likely to experience successful outcomes.
Subject of Research: Evoked compound action potential-controlled closed-loop spinal cord stimulation for refractory thoracic pain
Article Title: ECAP‐Guided Closed‐Loop Spinal Cord Stimulation for Axial Thoracic Pain: A Case Report
Article References: Soin, A., Kassis, S., Witte, R. J., Sloop, B., & Brittain, C. (2026). ECAP ‐Guided Closed‐Loop Spinal Cord Stimulation for Axial Thoracic Pain: A Case Report. Clinical Case Reports, 14(11), Article e73785. https://doi.org/10.1002/ccr3.73785
Image Credits: AI Generated
DOI: 10.1002/ccr3.73785
Keywords: spinal cord stimulation, closed-loop neuromodulation, axial thoracic pain, evoked compound action potentials, neuropathic spine pain, case report, pain management, ECAP, Guided, Closed, Loop, Spinal
News Source: Cassandra Pierce. (November 7, 2026). Closed-Loop Spinal Cord Stimulation Relieves Severe Thoracic Pain in Case Study. Scienmag.
