Peripheral Nerve Stimulation in Treatment of Intractable Postherpetic Neuralgia

Objective. This case report presents an application of peripheral nerve stimulation to a patient with intractable postherpetic neuralgia that conventional treatment failed to ameliorate. Methods. The patient underwent an uneventful peripheral nerve stimulator trial with placement of two temporal eight‐electrode percutaneous leads (Octrode leads, Advanced Neuromodulation Systems, Plano, TX, USA) into the right subscapular and right paraspinal area of the upper thoracic region. Results. Upon experiencing excellent pain relief over the next two weeks, the patient underwent implantation of permanent leads two weeks later and reported sustained pain relief. Conclusion. Peripheral nerve stimulation offers an alternative treatment option for intractable pain associated with postherpetic neuralgia, especially for elderly patients where treatment options are limited due to existing comorbidities. Further studies are warranted.     

Peripheral Nerve Stimulation for Unremitting Ophthalmic Postherpetic Neuralgia

Postherpetic neuralgia (PHN) is a common cause of chronic pain in the elderly. Opioids and adjunctive analgesics such as antidepressants and anticonvulsants effectively reduce discomfort in many patients, while others have pain that remains resistant to all forms of therapy. Spinal cord stimulation has shown promise for severe truncal and extremity PHN, but has no impact on neuralgias of cranial nerve origin. Peripheral nerve stimulation has been described for such problems as chronic regional pain syndrome, but to date has not been reported for cranial nerve syndromes. This article describes the cases in which an 86‐year‐old man and a 76‐year‐old woman with intractable PHN of greater than 6 and 4 years, respectively, were effectively treated with peripheral nerve stimulation of the ophthalmic division of the trigeminal nerve.     

Supraspinal Effects of Dorsal Root Ganglion Stimulation in Chronic Pain Patients

Objectives: Dorsal root ganglion stimulation (DRGS) has become a popular neuromodulatory treatment for neuropathic pain. We used magnetoencephalography (MEG) to investigate potential biomarkers of pain and pain relief, based on the differences in power spectral density (PSD) during varying degrees of pain and how these oscillations change during DRGS-mediated pain relief.Materials and Methods: Thirteen chronic pain patients with implanted dorsal root ganglion stimulators were included in the MEG analysis. MEG Recordings were performed at rest while the stimulator was turned ON or OFF. Numerical rating scale (NRS) scores were also recorded before and after DRGS was turned OFF and ON. Power spectral and source localization analyses were then performed on preprocessed MEG recordings.Results: With DRGS-OFF, patients in severe pain had significantly increased cortical theta (4–7 Hz) power and decreased cortical alpha (7–13 Hz) power compared to patients reporting less pain. This shift in power toward lower frequencies was contrasted by a shift toward the higher frequency power spectrum (low beta 13–20 Hz activity) during DRGS-mediated pain relief. A significant correlation was found between the increase in low beta activity and the degree of reported pain relief.Conclusion: Our results demonstrate increased low-frequency power spectral activity in chronic pain patients in the absence of stimulation which shifts toward higher frequency power spectrum activity in response to therapeutic DRGS. These cortical changes in response to DRGS provide support for the use of neuroimaging in the search for potential biomarkers of pain.     

Effect of Temporary Spinal Cord Stimulation on Postherpetic Neuralgia in the Thoracic Nerve Area

Objectives. The pain associated with herpes zoster can be classified as acute phase, persistent phase, or chronic phase, but if it is prolonged, it becomes resistant to treatment. It is clinically important to prevent transition to postherpetic neuralgia after the onset of herpes zoster, and the outcome depends on whether continuous and potent pain management can be achieved between the acute and persistent phases. We evaluated the effect of pain management leading to quick termination of pain using temporary spinal cord stimulation (SCS) which does not require implantation of a device. Materials and Methods. We performed continuous epidural blocks (CEB) on 52 patients with severe persistent pain of postherpetic neuralgia in the thoracic nerve area, and also inserted spinal stimulation leads in 14 who showed no improvement in the severe pain with concomitant pharmacotherapy. We expected to see the termination of pain with adequate analgesic effects mainly with SCS, and secondarily with the epidural analgesia as rescue therapy. Results. Severe pain accompanied by sensory dysfunction remained in 14 cases. By introducing SCS to the CEB, the visual analog scale baseline was rapidly reduced. Less epidural analgesia was required and the adverse reactions of lowered blood pressure in three cases and urinary retention in seven cases disappeared soon. The self‐rated satisfaction was higher with SCS than with CEB in all 14 cases, because it is highly controllable and has minimal activities of daily living–lowering effects. Conclusion. Temporary SCS, which does not require implantation of a device, may have a potent analgesic effect on severe pain in patients in the persistent phase after herpes zoster, and prevent transition to postherpetic neuralgia.     

Successful Treatment of Chronic Neuropathic Pain With Subcutaneous Peripheral Nerve Stimulation: Four Case Reports

Introduction. Chronic pain is a prevalent medical condition in the general population and is one of the most common reasons patients visit their primary care doctors. When the pain is resistant to the common treatment modalities, it presents a challenge for the physician and may have profound consequences for the quality of life of the patient. Methods. We present four case reports in which subcutaneous peripheral nerve stimulation was successfully used to treat chronic neuropathic pain after all other treatment efforts had failed. Results. In all cases, the patients underwent a trial of peripheral nerve stimulation with good results. The patients reported decreased use of pain medications, increased quality of life, and high satisfaction with the procedure results. Conclusion. The use of subcutaneous peripheral nerve stimulation as a viable treatment alternative in certain cases of chronic neuropathic pain should continue to be rigorously evaluated.     

Selective Nerve Root Stimulation (SNRS) for the Treatment of Intractable Pelvic Pain and Motor Dysfunction: A Case Report

Interstitial cystitis is the most disabling nonmalignant disorder seen by urologists. Chronic debilitating urinary bladder symptoms (severe pain and pelvic floor muscular dysfunction) often progress despite maximal medical attempts at management. Although the exact cause remains unknown, a neuropathic etiology has recently been suggested( 1 , 2 ). This case report describes the use of Selective Nerve Root Stimulation (SNRS) for the treatment of intractable pelvic pain and motor dysfunction in a patient with Interstitial cystitis (IC).     

The Effects of Temporary Spinal Cord Stimulation (or Spinal Nerve Root Stimulation) on the Management of Early Postherpetic Neuralgia from One to Six Months of Its Onset

Objective: We examined the efficacy of temporary spinal cord stimulation involving the insertion of only a needle and quadripolar lead into the epidural space and applied using an extracorporeal stimulation generator for a few weeks of early postherpetic neuralgia from one to six months of its onset. Materials and Methods: Temporary spinal cord stimulation was applied in 33 patients with postherpetic neuralgia and in whom epidural block was effective. Temporary spinal cord stimulation was applied over seven days, and analgesic effects was evaluated based on visual analog scale (VAS) values before and after one, three, and six months following treatment. An analgesic effect was defined as a decrease of over 50% in the VAS value compared with before treatment. Results: VAS values decreased significantly from 68.1 mm (standard deviation [SD]± 15.2) before treatment to 37.5 mm (SD ± 20.4) after one month, to 38.0 mm (SD ± 18.7) after three months, and to 35.0 mm (SD ± 21.3) after six months. In 21/33 (63.6%) cases, an analgesic effect, defined as a decrease in the VAS value of greater than 50%, was observed one month after treatment, in 20/33 (60.6%) cases such an effect was observed three months after treatment, and in 21/33 (63.6%) cases the effect was still observed six months after treatment. Conclusions: Temporary spinal cord stimulation is an effective analgesic method for early postherpetic neuralgia from one to six months of its onset.     

Three-Year Outcomes After Dorsal Root Ganglion Stimulation in the Treatment of Neuropathic Pain After Peripheral Nerve Injury of Upper and Lower Extremities

ObjectivesTraumatic peripheral nerve injuries (PNI) often result in severe neuropathic pain which typically becomes chronic, is recalcitrant to common analgesics, and is associated with sleep disturbances, anxiety, and depression. Pharmacological treatments proven to be effective against neuropathic pain are not well tolerated due to side effects. Neuromodulative interventions such as peripheral nerve or spinal cord stimulation have generated mixed results and may be limited by reduced somatotopic specificity. Dorsal root ganglion (DRG) stimulation may be more effective in this etiology.Materials and MethodsTwenty-seven patients were trialed with a DRG neurostimulation system for PNI; trial success (defined as ≥50% pain relief) was 85%, and 23 patients received a permanent stimulator. However, 36-month outcome data was only available for 21 patients. Pain, quality of life, mental and physical function, and opioid usage were assessed at baseline and at 3-, 6-, 12-, 18-, 24-, and 36 months post-permanent implant. Implant-related complications were also documented.ResultsCompared to baseline, we observed a significant pain relief (p < 0.001) at 3 (58%), 12 (66%), 18 (69%), 24 (71%), and 36 months (73%) in 21 patients (52.5 ± 14.2 years; 12 female), respectively. Mental and physical function showed immediate and sustained improvements. Participants reported improvements in quality of life. Opioid dosage reduced significantly (p < 0.001) at 3 (30%), 12 (93%), 18 (98%), 24 (99%), and 36 months (99%), and 20 of 21 patients were completely opioid-free after 36 months. There were five lead migrations and two electrode fractures (corrected by surgical intervention) and one wound infection (conservatively managed).ConclusionsDRG neuromodulation appears to be a safe, effective, and durable option for treating neuropathic pain caused by PNI. The treatment allows cessation of often ineffective pharmacotherapy (including opioid misuse) and significantly improves quality of life.     

Continuous Intrathecal Infusion of Opioid and Bupivacaine in the Treatment of Refractory Pain Due to Postherpetic Neuralgia: A Case Report

This report details the course of a 77-year-old patient suffering mild pain from operated tongue cancer and excruciating, intractable pain from thoracic (T6–T8) post-herpetic neuralgia (PHN), The mouth pain was treated with nonopioid analgesics, as the patient had personal objections to opioid treatment. All the components of the pain from his PHN (continuous burning pain, intermittent lancinating stabbing pain, and tactile allodynia) were successfully treated with an Intrathecal Infusion of buprenorphine (0.03 mg/ml) and bupivacaine (4.75 mg/ml) administered via an externalized intrathecal catheter with the tip located at T9–T10 intervertebral disc. The treatment started three months after the appearance of the herpetic eruption and lasted 294 days until the patient died of malnutrition and the progression of his tongue cancer. During treatment, he experienced satisfactory pain relief from his PHN; the mean visual analogue scores (VASmean), recorded on a scale from 0 to 10, ranged from 1 to 2, compared to 9 to 10 before starting the intrathecal treatment. Analgesia was established with 0.2–0.315 mg/day of intrathecal buprenorphine and 90–100 mg/day of intrathecal bupivacaine. His undisturbed nocturnal sleep increased from 4 to 5–6 hours. The side-effects from the bupivacaine (urine retention requiring insertion of an indwelling urinary catheter, paresthesias, and mild pareses) were recorded. The patient could ambulate without support while on 90–100 mg/day of intrathecal bupivacaine. During a series of high-pressure oxygen treatments in a pressure chamber to treat an infection at the site of his tumor, the intrathecal infusion was interrupted. Thus, repeated observation of the intervals of severe pain and of analgesia were possible.     

An Innovative Case Report Detailing the Successful Treatment of Post‐Thoracotomy Syndrome with Peripheral Nerve Field Stimulation

Introduction: The detrimental effects of post‐thoracotomy pain syndrome is experienced worldwide; however, an effective treatment regimen remains elusive. Methods: We report a case of post‐thoracotomy pain syndrome effectively treated with peripheral nerve field stimulation (PNfS). Results: In the presented case, the patient underwent permanent placement of the PSfS device after a successful trial period. Upon follow‐up the patient has reported even better coverage over her painful areas and admits to 80% and higher reductions in her painful symptoms. Conclusion: Although the data are limited, in the aforesaid case report, post‐thoracotomy syndrome was effectively treated with the use of PNfS. This resulted in a significant pain perception reduction, increased quality of life and mobility, as well as decreased usage of oral pain medications. This adds to the accumulating case report and case series data that suggest PNfS is showing great promise as a pain reduction modality. Further, it is minimally invasive, can be trialled prior to implantation, and is reversible. Large prospective studies will be required in the future to further evaluate its efficacy before it can be widely accepted and adopted.     

Subcutaneous Peripheral Nerve Stimulation With Paddle Lead for Treatment of Low Back Pain: Case Report

Introduction. Peripheral nerve stimulation has become a useful tool in neuromodulation in the treatment of chronic and intractable pain syndromes. Method. While most of the reports in the literature describe the use of a subcutaneously placed small diameter cylindric lead, we present a case report of a 37‐year‐old man who did not have adequate axial back stimulation with such a lead. Conclusion. He had excellent stimulation and reduction of his pain after the device was replaced with an insulated subcutaneous paddle lead.