Cauda Equina Syndrome Associated with Dural Ectasia in Chronic Anlylosing Spondylitis

Cauda equina syndrome (CES) associated with dural ectasia is a rare neurologic complication in patients with longstanding ankylosing spondylitis (AS). We report a 68-year-old male with a 30-year history of AS who presented a typical symptom and signs of progressive CES, urinary incontinence and neuropathic pain of the lumbosacral radiculopathy. Computed tomography (CT) and magnetic resonance imaging (MRI) findings showed the unique appearances of dural ectasia, multiple dural diverticula, erosion of posterior element of the lumbar spine, tethering of the conus medullaris and adhesion of the lumbosacral nerve roots to the posterior aspect of the dural ectasia. Considering the progressive worsening of the clinical signs, detethering of the conus medullaris through resection of the filum terminale was performed through a limited laminectomy. However, the urinary incontinence did not improve and there was a partial relief of the neuropathic leg pain only. The possible pathogenetic mechanism of CES-AS and the dural ectasia in this patient with longstanding AS are discussed with a literature review.     

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.     

Sacral Nerve and Spinal Cord Stimulation for Intractable Neuropathic Pain Caused by Spinal Cord Infarction

Central cord pain is very difficult to relieve, even with the many kinds of medical and surgical treatments available. Following spinal cord infarctions, central cord pain can develop. The problems that may arise could include limb pain, pelvic pain, difficulties voiding, and difficulties defecating. We are reporting a case of central cord pain caused by a spinal cord infarction of the conus medullaris. Limb pain was reduced by spinal cord stimulation. Voiding and defecation difficulties and pelvic pain were reduced by sacral nerve stimulation. Thus, in a case involving both intractable limb and pelvic pain, a combination therapy of these two stimulations might be an effective treatment modality.     

A Case of Cauda Equina Syndrome in Early-Onset Chronic Inflammatory Demyelinating Polyneuropathy Clinically Similar to Charcot-Marie-Tooth Disease Type 1

To present a case of cauda equina syndrome (CES) caused by chronic inflammatory demyelinating polyneuropathy (CIDP) which seemed clinically similar to Charcot-Marie-Tooth disease type1 (CMT1). CIDP is an immune-mediated polyneuropathy, either progressive or relapsing-remitting. It is a non-hereditary disorder characterized by symmetrical motor and sensory deficits. Rarely, spinal nerve roots can be involved, leading to CES by hypertrophic cauda equina. A 34-year-old man presented with low back pain, radicular pain, bilateral lower-extremity weakness, urinary incontinence, and constipation. He had had musculoskeletal deformities, such as hammertoes and pes cavus, since age 10. Lumbar spine magnetic resonance imaging showed diffuse thickening of the cauda equina. Electrophysiological testing showed increased distal latency, conduction blocks, temporal dispersion, and severe nerve conduction velocity slowing (3 m/s). We were not able to find genetic mutations at the PMP 22, MPZ, PRX, and EGR2 genes. The pathologic findings of the sural nerve biopsy revealed thinly myelinated nerve fibers with Schwann cells proliferation. We performed a decompressive laminectomy, intravenous IgG (IV-IgG) and oral steroid. At 1 week after surgery, most of his symptoms showed marked improvements except foot deformities. There was no relapse or aggravation of disease for 3 years. We diagnosed the case as an early-onset CIDP with cauda equine syndrome, whose initial clinical findings were similar to those of CMT1, and successfully managed with decompressive laminectomy, IV-IgG and oral steroid.     

A Case Report of Subcutaneous Peripheral Nerve Stimulation for the Treatment of Axial Back Pain Associated With Postlaminectomy Syndrome

Objective. This article aims to present a case of the use of an alternative form of neuromodulation for the treatment of axial back pain associated with postlaminectomy syndrome. Materials and Methods. An elderly patient with long‐standing axial back pain in the setting of a prior decompressive laminectomy presented for evaluation and treatment. After failing to obtain significant benefit from more conservative measures, a trial of peripheral nerve stimulation (PNS) was performed. Results. The patient reported > 75% relief of his pain during the seven‐day trial period, and accordingly a permanent PNS system was implanted. The permanent system consisted of four Medtronic Quad Plus leads, two on each side of midline oriented horizontally over the L4–5 paraspinous muscles. Our patient was ultimately weaned off of all narcotic medications and, at one year follow‐up, continues to report > 90% reduction of pain.     

Sacral Nerve Stimulation With Percutaneous Dorsal Transforamenal Approach in Treatment of Isolated Pelvic Pain Syndromes

Objectives. The aim of the study was to test the effectiveness of sacral nerve stimulation (SNS) performed by a transforamenal approach in patients with isolated chronic intractable pelvic pain. Materials. Sevenpatients with intractable pelvic pain underwent implantation of self‐anchoring leads by way of the dorsal S3 foramen in four cases and of the dorsal S4 foramen in three cases. Patients with pain improvement > 50% underwent sacral nerve root stimulation device implantation. SNS therapeutic efficacy was measured using a visual analog scale (VAS) and its effects on quality of life (QoL) using the SF‐36 scale. Results. During test stimulation five patients had significant and permanent pain relief and subsequently underwent implantation of a permanent device. VAS score improvement was evident in these patients and remained unchanged at 3, 6, and 12 months (median 8 months); SF‐36 QoL questionnaire also revealed significant improvement in many domains of QoL including all the four physical domains and three of the four mental domains. There were three complications in our seven patients: one lead fracture, one lead displacement in the presacral space, and one patient who developed pain at the implantable pulse generator site. Conclusions. Transforamenal SNS is effective in relieving isolated pelvic pain but a high complication rate was found.     

Subcutaneous Peripheral Nerve Stimulation Treatment for Chronic Pelvic Pain

Two cases of chronic pelvic pain of unknown etiology with symptoms referable to the low abdominal wall are presented. These patients are often difficult to manage because of multiple causes and multiple pathways for pain transmission from the pelvis. In these cases, the patients’ complaints were refractory to medication management, as well as diagnostic and therapeutic nerve blockade. After careful evaluation, a successful trial of peripheral nerve stimulation was followed by permanent implantation of low abdominal subcutaneous leads and a pulse generator device. The patients reported excellent relief of their chronic pelvic pain. The use of neuromodulation via peripheral stimulation deserves further investigation as an alternative to spinal cord stimulation for chronic pelvic pain.     

Endoscopic Discectomy for the Cauda Equina Syndrome During Third Trimester of Pregnancy

Low back pain is common during pregnancy. However, the prevalence of symtomatic lumbar disc herniation is rare, and cauda equina syndrome due to disc herniation during pregnancy is even rarer. We report a rare case of lumbar disc herniation causing cauda equina syndrome during third trimester of pregnancy which successfully treated by endoscopic discectomy. This case shows that endoscopic discectomy can be the treatment option for the lumbar disc herniation during pregnancy.     

Treatment of Chronic Intractable Hip Pain After Iliac Crest Bone Graft Harvest Using Peripheral Nerve Field Stimulation

Introduction: Autologous iliac crest bone graft (ICBG) harvest is a common procedure performed at the time of many spinal surgical procedures and associated with morbidity incurred at the harvest site, the most troublesome being chronic donor site pain. Methods: The patient underwent an uneventful peripheral nerve field stimulation (PNFS) trial with percutaneous placement of two temporary eight‐electrode leads (Medtronic Inc., Minneapolis, MN, USA) placed in epifascial plane over the left ICBG harvest site. Results: After experiencing excellent pain relief over the next two days, the patient was implanted with permanent leads and generator two weeks later and reported sustained pain relief at 12‐month follow‐up visit. Discussion: Peripheral nerve field stimulation provides an effective treatment option for patients suffering from chronic hip pain after ICBG harvest who have failed conservative treatment. PNFS may provide pain relief with advantages over conservative treatments and more invasive techniques. Conclusion: Peripheral nerve field stimulation offers an alternative treatment option for select patients with chronic hip pain after ICBG harvest.     

Tripolar Spinal Cord Stimulation for the Treatment of Abdominal Pain Associated With Irritable Bowel Syndrome

Objectives: The objective of this case report is to describe the use of transverse tripolar dorsal column stimulation in a patient with a history of irritable bowel syndrome (IBS) associated with abdominal pain resistant to conservative treatments. Method: We report a 36‐year‐old man who presented to the pain clinic with an eight‐year history of IBS (constipation predominant with occasional diarrheal episodes), with “crampy and sharp” abdominal pain. He also had nonradicular thoracic spine pain due to thoracic scoliosis. Both pains were affecting his ability to function as an attorney. Prior conservative therapy, including psychologic treatment, antidepressants, and opioids, was without any benefits. Results: The use of a spinal cord stimulator (SCS) was discussed with the patient. The procedure was performed after Institutional Review Board approval. A tripolar SCS was implanted at the T8 level using one‐eight contact and two‐four contact percutaneous leads based on paresthesia reproduction of patient's areas of discomfort. This tripolar spinal cord stimulation provided relief of abdominal and thoracic pain, and better management of gastrointestinal symptoms. The patient was followed‐up for one year, and his quality of life also was improved via the IBS‐Severity Scoring System quality of life tool. Conclusions: The use of the tripolar SCS in this patient provided relief of abdominal and thoracic spine pain, regulated bowel habits, and improved the patient's quality of life. We believe that the use of SCS should be considered as a treatment option in patients with IBS when all conservative treatments failed.     

Long-Term Trigeminal Nerve Stimulation as a Treatment for Ocular Pain

ObjectivesOcular pain symptoms (e.g., hypersensitivity to light and wind, “burning” sensations) can be debilitating and difficult to treat. Neuromodulatory therapies targeting sensory trigeminal and central pain pathways may help treat chronic ocular pain refractory to traditional therapies. The current study evaluates the long-term effects of a trigeminal neurostimulator (TNS) on ocular pain.Materials and MethodsRetrospective review of 18 individuals at the Miami Veterans Affairs Eye Clinic with chronic, severe ocular pain who were prescribed and used TNS at home for ≥3 months. The primary outcome measures were 1) ocular symptom intensity over a 24-hour recall period (dryness, pain, light sensitivity, wind sensitivity, burning; rated on 0–10 scales) captured pre-TNS and at monthly follow-up intervals and 2) side effects. The frequency and duration of TNS was a secondary outcome measure.ResultsThe mean age of the population (n = 18) was 57.5 years (range, 34–85 years) with a male majority (67%). Two individuals discontinued use due to lack of efficacy and one due to confounding health issues. Initial mean weekly frequency of TNS use was 3.7 ± 1.9 sessions of 25.8 min at month 1 and 2.7 ± 2.3 sessions of 28.0 min at month 6. At six months, pain intensity (↓ 31.4%), light sensitivity (↓ 36.3%), wind sensitivity (↓ 32.6%), and burning sensation (↓ 53.9%) were all decreased compared to baseline (p < 0.01 for all); greater decreases in ocular pain were noted in individuals with migraine (n = 10) than those without migraine (n = 8). No significant change was noted in mean dryness scores. Fifteen subjects experienced sedation with TNS use, persisting throughout the follow-up visits. No other adverse effects were communicated by any subjects.ConclusionOur study suggests TNS is a safe, adjunctive treatment option in individuals with severe, chronic ocular pain. Individuals demonstrated gradual, continual improvement in pain symptoms over time within a multimodal approach.     

Direct Sciatic Nerve Electrical Stimulation for Complex Regional Pain Syndrome Type 1

ObjectiveFoot and leg pain in complex regional pain syndrome (CRPS) presents a challenge even with neuromodulation techniques such as spinal cord stimulation (SCS). We report our experience with a novo technique of direct sciatic nerve electrical stimulation (DISNES) for intractable foot and leg pain in CRPS I.Materials and MethodsFollowing Research Ethics Board (REB) approval, data were gathered for 16 patients (10 women and 6 men, age 26–61 years) who had been subjected to ipsilateral DISNES. All 16 patients had failed conventional medical management. As well, seven subjects were previously treated with SCS for CRPS I pain. These subjects reported pain relief in the thigh and leg, however the SCS was unable to alleviate the disabling foot pain despite varied and multiple programming techniques. The remaining nine subjects were treated primarily with DISNES. Evaluation was done using visual analog scale (VAS), Oswestry Disability Index version 2 (ODI), and quality of life (EQ-5D and SF-36) scores done both pre-DISNES and at two follow-ups.ResultsVAS scores decreased by 59% at follow-up (F/U) 1 (P = 0.00001) and 46% F/U 2. ODI improving by 40% F/U 1 (P = 0.0038) and 37% F/U 2. SF-36 scores improved by 69% F/U 1 (P = 0.015) and 80% F/U 2. EQ-5D scores improved significantly by F/U 1 (P = 0.00030) but insignificantly at F/U 2 (P = 0.81). There was also a rapid resolution of autonomic features such as edema, hyperemia, and allodynia (within 7–10 days). Three subjects returned to work post-DISNES.ConclusionOur study shows that DISNES helps to control the disabling foot pain in CRPS I, thus improving the quality of life, improving ambulation and decreasing disability. DISNES also alleviates autonomic features and dystonia in CRPS I. Further studies are needed to determine long-term efficacy as this study pool is limited in size and follow-up period.     

Sacral Nerve Stimulation for the Treatment of Sacroiliac Joint Dysfunction: A Case Report

Introduction: Sacroiliac joint (SIJ) dysfunction is a significant contributing factor in 10–30% of individuals with lower back pain. However, definitive diagnostic methods and treatments are still controversial. Methods: We present a case of a 41‐year‐old woman with left buttock pain, referred pain to the left leg, and dyspareunia. Her visual analogue scale (VAS) pain score was 9/10. Although we performed intramuscular injection into piriformis muscle, intra‐articular injection into SIJ, and radiofrequency denervation for the treatment of SIJ pain, her pain repeatedly improved and was reaggravated. Sacral nerve stimulation to the left first sacral foramen via the retrograde cephalocaudal approach was performed. Results: Her VAS pain score decreased to 2–3/10 following sacral nerve stimulation to the left first sacral foramen via the retrograde cephalocaudal approach. Before undergoing sacral nerve stimulation, she had taken anti‐depressants, anti‐anxietics, analgesics, and anti‐convulsants. After the procedure, she required intermittent analgesics only. Conclusions: Sacral nerve stimulation with a percutaneous retrograde cephalocaudal approach is considered to be a useful therapeutic option in the treatment of intractable SIJ dysfunction.     

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).     

Median Nerve Stimulation in a Patient with Complex Regional Pain Syndrome Type II

A 54-year-old man experienced injury to the second finger of his left hand due to damage from a paintball gun shot 8 years prior, and the metacarpo-phalangeal joint was amputated. He gradually developed mechanical allodynia and burning pain, and there were trophic changes of the thenar muscle and he reported coldness on his left hand and forearm. A neuroma was found on the left second common digital nerve and was removed, but his symptoms continued despite various conservative treatments including a morphine infusion pump on his left arm. We therefore attempted median nerve stimulation to treat the chronic pain. The procedure was performed in two stages. The first procedure involved exposure of the median nerve on the mid-humerus level and placing of the electrode. The trial stimulation lasted for 7 days and the patient''s symptoms improved. The second procedure involved implantation of a pulse generator on the left subclavian area. The mechanical allodynia and pain relief score, based on the visual analogue scale, decreased from 9 before surgery to 4 after surgery. The patient''s activity improved markedly, but trophic changes and vasomotor symptom recovered only moderately. In conclusion, median nerve stimulation can improve chronic pain from complex regional pain syndrome type II.     

Lumbar and Sacral Nerve Root Stimulation (NRS) in the Treatment of Chronic Pain: A Novel Anatomic Approach and Neuro Stimulation Technique

Objective. The conventional technique used to stimulate the lumbar dermatomes is by stimulation of the dorsal columns of the spinal cord. Until recently, stimulation of nerve roots had not been successfully accomplished. We had performed selective nerve root cannulations for the placement of temporary catheters at cervical, thoracic, lumbar, and sacral levels in chronic pain patients using a caudad rather than craniad approach. We hypothesized that by stimulating the nerve roots we could improve paresthesia coverage in areas which cannot be covered effectively by spinal cord stimulation (SCS). To test this hypothesis, we have performed trials of nerve root stimulation (NRS) in patients who had failed SCS, or who were not candidates for SCS because their pain was otherwise inaccessible to stimulation. Methods. Five patients who had been unresponsive to conservative treatment, surgery, or SCS underwent 7-day trials with NRS. The diagnoses included: ilioinguinal neuralgia, discogenic low back pain, failed back syndrome, vulvodynia, and interstitial cystitis. We collected paresthesia maps, pain maps, pain visual analog scale (VAS) scores, and patient satisfaction ratings. Results. Paresthesia coverage was above 75% in all patients. VAS scores declined from a mean of 9 ± 1.0 to 2.4 ± 2.1 (p < 0.05, n= 5), all 5 patients requested permanent implantation, and 4 have been implanted so far. Conclusions. Lumbar and sacral NRS trials resulted in adequate paresthesia coverage and effective pain relief in all 5 patients. Further clinical trials to evaluate long-term success rates and safety are indicated. Detailed mapping studies are needed to evaluate the relationship between electrode placement and paresthesia patterns as well as the optimal stimulation parameters.