High cervical spinal cord stimulation after failed dorsal root entry zone surgery for brachial plexus avulsion pain

[Electrical dorsal root ganglion stimulation (DRGS) for the treatment of refractory postherpetic neuralgia]

Postherpetic neuralgia (PHN) is a rare complication of herpes zoster characterized by prolonged and excruciating pain. Traditional treatments for PHN, such as analgesics, anticonvulsants and antidepressants, do not always bring the desired result. One promising alternative that is attracting the attention of the scientific community is dorsal root ganglion stimulation (DRGS). This method focuses on targeted and precise targeting of the source of pain, providing a new level of effectiveness in the treatment of PHN.

OBJECTIVE

A retrospective analysis of the technique and results of implantation of a permanent device for stimulating the spinal ganglia in patients with refractory PHN at the Burdenko Neurosurgical Center.

MATERIAL AND METHODS

The study was conducted in 7 patients (5 men, 2 women) with refractory PHN in the period from 2018 to 2020. The age of the patients ranged from 57 to 84 years (average age 74±8.4). All patients were implanted with Boston systems (Precision or Spectra versions). Stimulation parameters: pulse width - 120-210 μs, frequency - 30-130 Hz, amplitude at the lower limit of the appearance of paresthesia with the possibility of increasing with increased pain up to 5 mA. The position of the electrode depended on the location of the pain. All systems were implanted under X-ray guidance.

RESULTS

The duration of follow-up observation was more than 2.5 years. The average pain intensity one year after treatment was 3.42±2.45 points on the visual analogue scale (VAS) (a 62.3% decrease in intensity compared to baseline). In 3 (42.8%) patients, the result was characterized by us as «excellent» (intensity according to VAS decreased by 75% or more), in 1 (14.2%) - as «good» (intensity according to VAS decreased by 50-74%), in 1 (14.2%) - as «moderate» (VAS intensity decreased by 25-49% and in 2 (28.5%) as «unsatisfactory» (VAS intensity decreased by less than 25%, or postoperative complications occurred).

CONCLUSION

Given the complicated nature of PHN, the use of dorsal ganglion stimulation appears to be a promising and innovative treatment approach. Further research is needed to introduce this technique into clinical practice for the treatment of patients suffering from PHN.

Tight adhesions after spinal cord stimulation observed during dorsal root entry zone lesioning for pain after spinal root avulsion: illustrative cases

BACKGROUND

Patients often experience strong shooting pains after spinal root avulsion. The efficacy of spinal cord stimulation (SCS) for this type of pain is inconsistent; however, dorsal root entry zone (DREZ) lesioning (DREZ-lesion) has often proven to be an effective treatment modality. The authors report two cases in which DREZ-lesion was performed to treat pain after spinal root avulsion after implantation of SCS, but the operations were challenging due to strong adhesions.

OBSERVATIONS

The authors present two cases of patients with pain after spinal root avulsion in whom SCS implantation was only temporarily effective. Patients complained of persistent and paroxysmal shooting pains in the upper extremities. SCS removal and DREZ-lesion were performed, but adhesions in the epidural and subdural space contacting the leads were strong, making it difficult to expose the DREZ.

LESSONS

Although adhesions around the spinal cord can be caused by trauma, the authors believe that in these cases, the adhesions could have been caused by the SCS leads. There are few previous reports confirming the efficacy of SCS in treating pain after spinal root avulsion; therefore, caution is required when considering SCS implantation.

Dorsal Root Entry Zone Lesioning for Brachial Plexus Avulsion Injuries: Case Series and Literature Review

Introduction: Brachial plexus avulsion (BPA) injuries commonly occur secondary to motor vehicle collisions, usually in the young adult population. These injuries are associated with significant morbidity, and up to 90% of patients suffer from deafferentation pain. Neuromodulation procedures can be efficacious in the treatment of refractory neuropathic pain, although the treatment of pain due to BPA can be challenging. Dorsal root entry zone (DREZ) lesioning is a classical and effective neurosurgical technique which has become underutilized in treating refractory root avulsion pain.

Methods: A systematic review of the different technical nuances, procedural efficacy, and complication profiles regarding DREZ lesioning for BPA injuries in the literature is included. We also present an institutional case series of 7 patients with BPA injuries who underwent DREZ lesioning.

Results: In the literature, 692 patients were identified to have undergone DREZ lesioning for pain related to BPA. In 567 patients, the surgery was successful in reducing pain intensity by over 50% in comparison to baseline (81.9%). Complications included transient motor deficits (11%) and transient sensory deficits (11%). Other complications including permanent disability, cardiovascular complications, infections, or death were rare (<1.9%). In our case series, all but one patient achieved >50% reduction in pain intensity, with the mean pre-operative pain of 7.9 ± 0.63 (visual analog scale) reduced to 2.1 ± 0.99 at last follow-up (p < 0.01).

Conclusion: Both the literature and the current case series demonstrate excellent pain severity reduction following DREZ ablation for deafferentation pain secondary to BPA.

DREZotomy in the treatment of deafferentation pain: review of results and analysis of predictive factors for success

BACKGROUND AND OBJECTIVES

The treatment of deafferentation pain by spinal DREZotomy is a proven therapeutic option in the literature. In recent years, use of DREZotomy has been relegated to second place due to the emergence of neuromodulation therapies. The objectives of this study are to demonstrate that DREZotomy continues to be an effective and safe treatment and to analyse predictive factors for success.

PATIENTS AND METHODS

A retrospective study was conducted of all patients treated in our department with spinal DREZotomy from 1998 to 2018. Bulbar DREZotomy procedures were excluded. A visual analogue scale (VAS) and the reduction of routine medication were used as outcome variables. Demographic, clinical and operative variables were analysed as predictive factors for success.

RESULTS

A total of 27 patients (51.9% female) with a mean age of 53.7 years underwent DREZotomy. The main cause of pain was brachial plexus injury (BPI) (55.6%) followed by neoplasms (18.5%). The mean time of pain evolution was 8.4 years with a mean intensity of 8.7 according to the VAS, even though 63% of the patients had previously received neurostimulation therapy. Favourable outcome (≥50% pain reduction in the VAS) was observed in 77.8% of patients during the postoperative period and remained in 59.3% of patients after 22 months average follow-up (mean reduction of 4.9 points). This allowed for a reduction in routine analgesic treatment in 70.4% of them. DREZotomy in BPI-related pain presented a significantly higher success rate (93%) than the other pathologies (41.7%) (p=.001). No association was observed between outcome and age, gender, DREZ technique, duration of pain or previous neurostimulation therapies. There were six neurological complications, four post-operative transient neurological deficits and two permanent deficits.

CONCLUSION

Dorsal root entry zone surgery is effective and safe for treating patients with deafferentation pain, especially after brachial plexus injury. It can be considered an alternative treatment after failed neurostimulation techniques for pain control. However, its indication should be considered as the first therapeutic option after medical therapy failure due to its good long-term results.

Spinal Cord Stimulation for Neuropathic Pain Treatment in Brachial Plexus Avulsions: A Literature Review and Report of Two Cases

BACKGROUND

At least 50% of individuals who suffer a brachial plexus avulsion (BPA) will develop chronic pain, frequently more debilitating than their functional limitations. Similar to other neuropathic pain states, BPA pain is often refractory to pharmacological agents. Despite spinal cord stimulation (SCS) first being used for BPA in 1974, there have been no published literature reviews examining the current evidence of SCS for the treatment of neuropathic pain following BPA. In addition to a clinical review of the literature for this indication, we also share our experience with high-frequency SCS (HF-SCS) for BPA-related pain.

METHODS

MEDLINE and EMBASE databases were searched. All published articles including at least one BPA individual treated with SCS for pain treatment were included.

RESULTS

The initial search identified 288 articles, of which 13 met inclusion criteria for a total of 41 patients. These patients were primarily male and underwent SCS with reported improved pain scores.

CASE REPORTS

HF-SCS leads were percutaneously placed in two male patients who suffered BPA from traumatic injuries. At follow-ups of 13 and eight months, respectively, both patients continued to report an improvement in their pain.

CONCLUSIONS

Despite published reports showing benefit for pain control in patients with BPA, the overall low quality, retrospective evidence included in this review highlights the need for a rigorous prospective study to further address this indication.

The proposed use of cervical spinal cord stimulation for the treatment and prevention of cognitive decline in dementias and neurodegenerative disorders

Cervical spinal cord stimulation is a well-established treatment for intractable neuropathic upper extremity pain. More than 20years ago it was demonstrated that cervical spinal cord stimulation could engender an increase in cerebral blood flow. Cerebral blood flow has been shown to be decreased in many patients with dementia and in various neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Furthermore, there is evidence that reduced cerebral blood flow worsens neurodegenerative disease and may also predict which patients progress from mild cognitive impairment to full blown Alzheimer's disease. Thus, the identification of decreased cerebral blood flow in patients with early cognitive problems may offer clinicians a window of opportunity to intervene and prevent further brain damage. Further evidence that supports augmenting cerebral blood flow as an effective strategy for preventing and treating cognitive brain dysfunction comes from experimental studies with omental transposition. The author proposes cervical spinal cord stimulation as a titratable, programmable extracranial neuromodulation technique to increase cerebral blood flow for the purposes of improving cognitive function and preventing cognitive deterioration in patients with dementias and neurodegenerative disorders.

The Proper Use of Neurostimulation for Hand Pain

Upper extremity neuropathic pain states greatly impact patient functionality and quality of life, despite appropriate surgical intervention. This article focuses on the advanced therapies that may improve pain care, including advanced treatment strategies that are available. The article also surveys therapies on the immediate horizon, such as spinal cord stimulation, peripheral nerve stimulation, and dorsal root ganglion spinal cord stimulation. As these therapies evolve, so too will their placement within the pain care algorithm grounded by a foundation of evidence to improve patient safety and management of patients with difficult neuropathic pain.

A Novel Nonanchoring Technique for Implantation of Paddle Leads in the Cervical Spine Under Conscious Sedation

OBJECTIVES

Spinal cord stimulation (SCS) revision surgery remains common, with a negative impact on cost-effectiveness and outcomes. The primary goal of this report was to retrospectively study the need for revision surgery in a cohort of complex regional pain syndrome type I (CRPS-1) patients with newly implanted cervical surgical paddle leads, focusing on a method of implantation to reduce the need for revision surgery.

METHODS

Fifteen patients underwent implantation of paddle SCS leads in the cervical spine with cervical laminotomies under conscious sedation for CRPS-1 from 2008 to 2012. Electrodes were not anchored and 11 of the electrodes were three-column paddle leads. A disinterested third party performed initial chart reviews, supplemented by subsequent telephone interviews. The need for revision surgery was the endpoint. A single surgeon performed all implants with a consistent method.

RESULTS

There were no paddle electrode lead revisions required for suboptimal lead placement, fracture, migration, or infection at a median follow-up period of 22 months.

CONCLUSIONS

This study is the first to report on: 1) cervical electrode implantation with no anchoring; and 2) cervical paddle lead implantation (including three-column paddles) performed under conscious sedation. The specific method of nonanchoring of the paddle implants under conscious sedation may have contributed to low electrode lead revision rates.

Chronic post-traumatic neuropathic pain of brachial plexus and upper limb: a new technique of peripheral nerve stimulation

The aim of the study was to evaluate the effect on pain relief in patients with peripheral neuropathic pain after brachial plexus injuries using an implanted peripheral nerve stimulator applied directly to the nerve branch involved into the axillary cavity. Seven patients with post-traumatic brachial plexus lesions or distal peripheral nerve complaining of severe intractable chronic pain were enrolled in a single-centre, open-label trial. Conventional drugs and traditional surgical treatment were not effective. Patients underwent careful neurological evaluation, pain questionnaires and quantitative sensory testing (QST). Surgical treatment consists of a new surgical technique: a quadripolar electrode lead was placed directly on the sensory peripheral branch of the main nerve involved, proximally to the site of lesion, into the axillary cavity. To assess the effect, we performed a complete neuroalgological evaluation and QST battery after 1 week and again after 1, 6 and 12 weeks. All patients at baseline experienced severe pain with severe positive phenomena in the median (5) and/or radial (2) territory. After turning on the neuro-stimulator system, all patients experienced pain relief within a few minutes (>75 % and >95 % in most), with long-lasting pain relief with a reduction in mean Numerical Rating Scale (NRS) of 76.2 % after 6 months and of 71.5 % after 12 months. No significant adverse events occurred. We recommend and encourage this surgical technique for safety reasons; complications such as dislocation of electrocatheters are avoided. The peripheral nerve stimulation is effective and in severe neuropathic pain after post-traumatic nerve injuries of the upper limbs.

Differential efficacy of electric motor cortex stimulation and lesioning of the dorsal root entry zone for continuous vs paroxysmal pain after brachial plexus avulsion

BACKGROUND

Pain after traumatic brachial plexus avulsion (BPA) has 2 distinct patterns: continuous burning pain and paroxysmal shooting pain. Lesioning of the dorsal root entry zone (DREZotomy) is more effective for paroxysmal than continuous pain. It is unknown, however, whether electric motor cortex stimulation (EMCS) has a differential effect on continuous vs paroxysmal BPA pain.

OBJECTIVE

To analyze the differential effect of EMCS and DREZotomy on continuous vs paroxysmal BPA pain in a series of 15 patients.

METHODS

Fifteen patients with intractable BPA pain underwent DREZotomy alone (n = 7), EMCS alone (n = 4), or both procedures (n = 4). Pain intensity was evaluated with the Visual Analog Scale, and separate ratings were recorded for paroxysmal and continuous pain. Pain relief was categorized as excellent (> 75% pain relief), good (50%-75%), or poor (< 50%). Favorable outcome was defined as good or better pain relief.

RESULTS

Eight patients had EMCS; 7 were followed up for an average of 47 months. Of those 7 patients, 3 (42%) with continuous pain had favorable outcomes compared with no patients with paroxysmal pain. Eleven patients had DREZotomy; 10 were followed up for an average of 31 months. Of those 10 patients, 7 (70%) with paroxysmal pain had favorable outcomes compared with 2 (20%) with continuous pain.

CONCLUSION

EMCS was ineffective for paroxysmal pain but moderately effective for continuous pain. DREZotomy was highly effective for paroxysmal pain but moderately effective for continuous pain. It may be prudent to use EMCS for residual continuous pain after DREZotomy.

Activation of phospholipase-Cγ and protein kinase C signal pathways helps the survival of spinal motoneurons injured by root avulsion

The signaling transduction processes involved in avulsion-induced motoneuron (MN) death have not been elucidated. Using the brachial plexus root avulsion rat model, we showed that avulsion-activated phosphorylation of phospholipase-Cγ (PLCγ) and protein kinase C (PKC) occurred in injured spinal MNs within 72 h of injury. Moreover, some MNs positive for PLCγ and PKC are also positive for avulsion-induced neuronal nitric oxide synthase (nNOS). Inhibition of PLCγ/PKC signal pathway, either with PLCγ inhibitor, 1-[6-((17β-3-methoxyestra-1,3,5(10)-trien-17-yl) amino)hexyl]-1H-pyrrole-2,5-dione, or with PLCγ siRNA augmented avulsion-induced MN death. 1-[6-((17β-3-methoxyestra-1,3,5(10)-trien-17-yl) amino)hexyl]-1H-pyrrole-2,5-dione also inhibited PKC phosphorylation and exacerbated avulsion-induced reductions in the nNOS protein level in injured spinal segments. Moreover, activation of PLCγ/PKC signal pathway with PKC activator, phorbol-12-myristate-13-acetate, decreased avulsion-induced MN death. The temporal profile of PLCγ/PKC signaling appears to be crucial for the survival of spinal MNs after root avulsion. Our data suggest that PLCγ mediates, while PKC and nNOS are associated with, the avulsion-induced MN death in brachial plexus root avulsion.

High-level cervical spinal cord stimulation used to treat intractable pain arising from transverse myelitis caused by schistosomiasis

The efficacy of spinal cord stimulation (SCS) for treatment of various chronic painful conditions is well established. Very few reports have documented the use of SCS for treatment of chronic pain after spinal cord injury. We present a case showing a good outcome after such treatment, and suggest that high cervical stimulation may be efficacious. A 53-year-old male underwent SCS on the C1-3 level for treatment of intractable neuropathic pain below the T3 level, and in the upper extremities, arising from spinal cord injury resulting from transverse myelitis caused by schistosomiasis. High cervical SCS significantly improved the pain in the upper extremities and at the T3-T10 dermatome level. The patient continues to report excellent pain relief 9 months later. The present case suggests that high cervical stimulation may improve chronic pain in the upper extremities and the T3-T10 dermatome level arising from spinal cord injury.