bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Impedance a Parameter to be Taken into
Account in Spinal Cord Stimulation?
Authors: Abejon David
Published: March 2021

Background: Over the last few decades, spinal cord stimulation (SCS) has become one
of the main treatments in the therapeutic arsenal available to pain treatment units. New
stimulation systems have been developed and the indications of neurostimulation have
been expanded. The premises for a successful technique remain the same; good patient
selection, good surgical technique, and good management of electrical parameters when
programming.
Design: An observational report.
Objectives: The primary objective of the study was to determine the relationship between changes in impedance (R) and energy requirement (E) elicited by changes in patients posture. The postures analyzed were supine (S), sitting (SI), standing (ST), and walking (W). As a second objective, the difference produced in the energy requirement when
changing posture was analyzed.
Methods: A study was carried out in 70 patients with chronic intractable pain implanted
with a neurostimulation system between January 2000 and March 2006. We define the
perception threshold (Tp); the discomfort threshold (Td); and the therapeutic threshold
(Tt). The amplitude of perception was measured in mA. With the resulting data, the therapeutic range (TR) was determined. After performing all measurements with the patient
in the ST position, the neurostimulation system was shut off and the patient maintained
in the other position for 5 minutes before performing the measurements. The variables R
and E were compared by age groups, sex, implant duration, and the time since implant
placement. Patients were divided into groups according to whether the location of the implanted electrodes was cervical or thoracic. The full analysis by age, sex, and implant duration was performed in the cervical and thoracic implant groups.
Results: No correlation was found between impedance and posture. When the results
for R and E were analyzed by sex and age, no statistical differences were found in any of
the values in any position. The analysis of time since implant greater than or less than 6
months did not find differences in the energy requirement, although there was a significant difference in the impedance value when patients were in the S position. No significant differences were observed in the analysis by age groups.
Key words: Impedance, posture change, spinal cord stimulation
Percutaneous Vertebroplasty for
Osteoporotic Fractures
Authors: Afzal Suhail
Published: March 2021

Background: Vertebral augmentation has been widely used to treat vertebral body
compression fractures caused by varied pathologies. The lifetime risk of a vertebral
body compression fracture is 16% for women and 5% for men, and exponential increase of osteoporotic fractures worldwide.
Purpose: To determine the efficacy and durability of percutaneous vertebroplasty for
the treatment of back pain associated with osteoporotic vertebral fractures.
Design: A prospective study.
Materials and Methods: A prospective evaluation of pain relief in 30 patients, with
mean age of 73.7 years, who underwent percutaneous injection of polymethyl methacrylate into 54 vertebrae under fluoroscopic guidance over a period of 35 months was
done. Before the procedure and at follow up, patients were asked to quantify their pain
on a visual analogue scale.
Results: The procedure was technically successful in all the patients. Mean duration
of follow up was 21.5 months (6-44months). Ninety-seven percent of the patients reported a significant relief 24 hours after the procedure. Ninety-two percent reported
significant improvement in back pain, previously associated with a compression fracture, as well as improved ambulatory ability. Before vertebroplasty, the VAS score was
8.91+/- 1.82 compared to a score of 2.02+/- 1.95 at follow up. The mean difference in
VAS score was significant (p<.0001). One patient had an asymptomatic epidural leak of
PMMA, however did not require any further intervention.
Conclusion: Percutaneous vertebroplasty of symptomatic osteoporotic vertebral compression fractures is a minimally invasive procedure that provides immediate and sustained pain relief in patients with refractory pain.
Key words: Compression fracture, osteoporosis; pain, vertebroplasty, polymethylmethacrylate
Acquisition of Spine Injection Skills Using a
Beef Injection Simulator
Authors: Behrend Michael
Published: March 2021

Background: Students of interventional spine procedures typically learn needle injection technique using cadaver specimens or live patients in an operating room. This can
be expensive, inefficient, uncomfortable to patients, and requires a significant time commitment from teaching staff.
Purpose: To present a simple and inexpensive simulator using a cut of beef as an injection model that can be used to teach certain components of interventional spine injection needle technique in a more efficient and cost effective fashion.
Basic Procedures: A needle injection practice model using beef muscle attached to
a plastic base was constructed. Students of interventional spine pain were instructed in
C-arm x-ray operation and basic needle handling technique, then performed a series of
mock injection procedures using this simulator. Procedure time, fluoroscopy time, and
accuracy were measured.
Main findings: Speed, accuracy of needle placement, and fluoroscopy time of the
subjects improved with the number of practice sessions completed. The subjects felt better prepared to perform live patient procedures as a result of this training.
Conclusions: Use of an inexpensive beef injection model is a valid, reliable, and feasible adjunct to teaching C-arm x-ray operation and spine injection needle technique to
beginning students of intervention spine pain management.
Keywords: models, educational ; models, anatomic; models, structural
Interventional Techniques in Ambulatory
Surgical Centers: A Look at the New
Payment System
Authors: Manchikanti Laxmaiah
Published: March 2021

There has been an explosive increase in procedures performed in surgery centers, with approximately 4,700 Medicare-certified surgery centers in the United States. Total ambulatory surgical center (ASC) payments have increased substantially: $1 billion in 1996, and $2.9 billion in
2006.
In June 1998, the Healthcare Financing Administration (HCFA; CMS), proposed an ASC rule in
which at least 60% of interventional procedures were eliminated from ASCs and the remaining 40% faced substantial cuts in payments. Following the publication of this rule, based on
public comments and demand, Congress intervened and delayed implementation of the rule
for several years.
The Medicare Prescription Drug, Improvement and Modernization Act of 2003 (MMA) granted
broad statutory authority to the Secretary of Health and Human Services to design a new ASC
payment system based on the hospital outpatient payment system. The Centers for Medicare
and Medicaid (CMS) published its proposed outpatient prospective system for ASCs in 2006,
setting ASC payments at 62% of HOPD payments. This rule faced substantial opposition from
providers, patients, and Congress. Consequently, CMS revised the rule with a 4-year transition
formula to provide ASCs with 65% of HOPD payments.
Based on the new proposed rule, most interventional pain management procedures in ASCs will
lose approximately 3% to 5% without taking into account that there have not been any increments since 2004, except for a few small increases for some procedures, along with the addition of office procedures, which can now be performed in an ASC setting. However, payments
for procedures moved from the office setting to ASCs remain at the lower office rates, which
face substantial cuts on their own.
The proposed CMS rule will have widespread effects on physician payments, ASC payments,
and particularly interventional pain management physicians.
Key words: Outpatient prospective payment system, ambulatory surgery center payment system, Government Accountability Office, Medicare Modernization and Improvement Act, interventional techniques
Transsacrococcygeal Approach to Ganglion
Impar Block for Management Of Chronic
Perineal Pain: A Prospective Observational
Study
Authors: Toshniwal Dr. Gokul R.
Published: March 2021

Background: The ganglion impar or ganglion of Walther is a solitary retroperitoneal
structure at the level of sacrococcygeal junction. It provides the nociceptive and sympathetic supply to the perineal structures. Chronic Perineal Pain (CPP) has been effectively
managed by ganglion impar block. In this study we analyze the feasibility, safety, and efficacy of ganglion impar block by transsacrococcygeal approach.
Design: An observational report.
Methods: In this prospective study, 16 consecutive patients who required ganglion impar block for CPP were followed for two months. After informed and written consent,
the ganglion impar was blocked under aseptic precautions, using a transsacrococcygeal
approach. The Visual Analogue Scale for pain (VAS) at presentation time required for the
pain to reduce by 50% to be considered effective and VAS was recorded at different time
points during 2-month follow-up, and time required to perform the procedure, number
of attempts, and any complications were also noted.
Results: All the blocks were effective with a mean duration of 12±3 minutes for 50%
reduction in VAS. The mean duration required to perform the procedure in neurolytic
block patients was 7.8±2 minutes and 5.7±1minutes in therapeutic block patients. There
were no adverse events. All the patients had significant pain relief during 2 month follow-up (P <0.05 compared to baseline). The mean VAS at 2 months was about 2. Statistical analysis was done by using paired “t”/Wilcoxon signed rank test.
Conclusion: A transsacrococcygeal approach for a ganglion impar block is a technically feasible and safe technique. We recommend this technique for neurolysis or radiofrequency ablation of the ganglion impar and for diagnostic blocks, especially when the
diagnosis and further plan of management is dependent on the response of the diagnostic block.
Key words: Sympathetically mediated perineal pain, ganglion impar block, transsaccrococcygeal approach
Acute Cardiovascular Effects of Epidural
Spinal Cord Stimulation
Authors: Schultz David M.
Published: March 2021

Background: Several animal studies support the contention that thoracic spinal
cord stimulation (SCS) might decrease arterial blood pressure.
Objective: To determine if electrical stimulation of the dorsal spinal cord in humans
will lower mean arterial pressure (MAP) and heart rate (HR).
Design: Case Series
Methods: Ten normotensive subjects that were clinically indicated for SCS testing
were studied. Two of the 10 patients who underwent testing were excluded from the
analysis because they did not respond to the Cold Pressor Test (CPT). Systolic blood
pressure, diastolic blood pressure, and heart rate were measured continuously at the
wrist (using the Vasotrac device). SCS was administered with quadripolar leads implanted into the epidural space under fluoroscopic guidance. SCS was randomly performed either in the T1-T2 or T5-T6 region of the spinal cord during normal conditions as well as during transient stress induced by CPT. The CPT was conducted by
immersing the non-dominant hand in ice-cold water for 2 minutes.
Results: There were moderate decreases in MAP and HR during SCS at the T5-T6
region compared to baseline that did not reach statistical significance. However, SCS
at the T1-T2 region tended to increase MAP and HR compared to baseline but the
change did not reach statistical significance. Arterial blood pressure was transiently
elevated by 9.4 ± 3.8 mmHg using CPT during the control period with SCS turned off
and also during SCS at either the T1-T2 region or T5-T6 region of the spinal cord (by
9.2 ± 5 mmHg and 10.7 ± 8.4 mmHg, respectively). During SCS at T5-T6, the CPT significantly increased MAP by 5.9±7.1 mmHg compared to control CPT (SCS off).
Conclusion: This study demonstrated that SCS at either the T1-T2 or T5-T6 region
did not significantly alter MAP or HR compared to baseline (no SCS). However, during
transcient stress (elevated sympathetic tone) induced by CPT, there was a significant
increase in MAP and moderate decrease in HR during SCS at T5-T6 region, which is
not consistent with previous data in the literature. Acute SCS did not result in adverse
cardiovascular responses and proved to be safe.
Key words: Spinal cord stimulation, mean arterial pressure, heart rate, cold pressor test
Piriformis Muscle Injection Using
Ultrasonography and Motor Stimulation –
Report of a Technique
Authors: Huerto Antonio P. S.
Published: March 2021

The piriformis muscle syndrome has been described in the literature since
1947 and accounts for 6-8% of patients presenting with buttock pain,
which may variably be associated with sciatica. Through the years, there
have been attempts to find safe and effective ways of managing this condition, whether through conservative treatment or with the use of interventional procedures. Several authors have reported injection techniques using
the following: nerve stimulation; fluoroscopy with electromyography; and
fluoroscopy with muscle stimulation. We aim to describe an injection method which is effective, simple, reproducible, easily available, and safe. This is
the first report on the combined use of ultrasonography and motor stimulation in performing piriformis muscle injection. Our technique offers advantages such as: markedly decreased radiation exposure for both patient and
doctor; improved visualization of sciatic nerve and surrounding muscles;
improved portability; the possibility of being performed as an office-based
procedure; and allows for an accurate confirmation of pain in the piriformis
muscle with stimulation.
Key words: Piriformis muscle, ultrasound, motor stimulation
Dural Puncture and Subdural Injection: A
Complication of Lumbar Transforaminal
Epidural Injections
Authors: Goodman Bradly S.
Published: March 2021

Case Report: Two cases are presented in which the complication of dural
puncture is documented in the context of a lumbar transforaminal epidural
steroid injection. The hazard of dural puncture during transforaminal epidural
injections, the anatomy of the dural and thecal sac, the potential for subdural
injections, and relevant literature are reviewed.
Design: Report of two cases.
Background: Lumbar transforaminal epidural steroid injections are a commonly employed procedure for the treatment of lumbar radiculopathy. The
optimal target point lies at the “6 o’ clock” position of the pedicle. Contrast
is injected to confirm proper placement of the needle and correct flow of the
medication through the epidural space. Despite apparent proper placement
of the needle, a potential complication exists of puncturing the dura while
performing this procedure. Spinal injectionists should recognize the subsequent contrast patterns associated with this complication.
Conclusion: Subdural and intrathecal spread of contrast is rarely seen with
transforaminal injections and thus can be easily overlooked. Becoming familiar with the images presented in these cases may help alert the interventionalist of a dural puncture, and thus avoid injection of medications into the intrathecal and subdural spaces.
Key words: Back pain, epidural steroid injection, subdural, intrathecal
Inferior Hypogastric Plexus Blockade:
A Transsacral Approach
Authors: Schultz David M.
Published: March 2021

Background: Despite recent refinements in the technique of hypogastric plexus
blockade, the lower pelvic organs and genitalia are innervated by fibers from the
pre-sacral inferior hypogastric plexus and these fibers are not readily blocked using
paravertebral or transdiscal approaches.
Design: Report of a technique to introduce a transsacral approach to blockade
of the inferior hypogastric plexus.
Methods: A technique for performing inferior hypogastric plexus blockade by
passing a spinal needle through the sacral foramen is described with 15 blocks in
11 patients.
Results: Fifteen inferior hypogastric plexus blocks were performed on 11 female
patients who presented with chronic pelvic pain. Pelvic pain was decreased following 11 of the procedures with pre- and post-pain scores (SD) of 7.4 (2.3) and
5.0 (2.7), respectively (P < 0.05). There were no complications or unusual occurrences.
Conclusions: This block can be performed safely and effectively if the interventionalist has a high degree of familiarity with sacral anatomy, refined needle steering technique, and expertise in fluoroscopy. Properly performed, transsacral blockade of the inferior hypogastric plexus is a safe technique for the diagnosis and
treatment of chronic pain conditions involving the lower pelvic viscera.
Key words: Pelvic pain, chronic pain, inferior hypogastric plexus block, superior
hypogastric plexus, transsacral approach.
Squamous Cell Carcinoma Occurring Within
Incision of Recently Implanted Spinal Cord
Stimulator
Authors: Atallah Joseph
Published: March 2021

Spinal Cord Stimulation (SCS) is a treatment option for chronic pain patients. Spinal
cord stimulation has been employed in the treatment of chronic pain for more than
30 years. The most common indication for SCS is the failed back syndrome with leg
pain. Its indications have expanded beyond back and lower extremities pain to include axial low back pain, CRPS, mesenteric ischemia, peripheral neuropathy, limb
ischemia, and refractory angina pectoris. The SCS has become a more versatile form
of analgesia.
The number of wound complications will surely rise in conjunction with the increasing number of devices being implanted.
We describe a case of a well-differentiated squamous cell carcinoma occurring within the incision site of a recently implanted spinal cord stimulator early in the postoperative period.
The patient developed a rapidly growing mass within the leads incision. The mass
was confirmed to be squamous cell carcinoma by biopsy. The mass was excised under local anesthesia with appropriate margins. It was determined that the carcinoma
did not extend below the dermis, and that there was no involvement of the underlying fascia. The device was tested for proper functioning, and the leads were thus
left in place.
While the development of skin malignancies in surgical wounds has been described
in the literature, to our knowledge there have been no reports of a cutaneous neoplasm developing early in the postoperative period after spinal cord stimulator implantation.
Key words: Spinal cord stimulator, CRPS type 1, squamous cell carcinoma
Efficacy of Fluoroscopically Guided Steroid
Injections in the Management of Coccydynia
Authors: Mitra Raj
Published: March 2021

Background: Coccydynia is a rare but painful disorder characterized by axial coccygeal pain which is typically exacerbated by pressure. Management includes physical
therapy/rectal manipulation, use of anti-inflammatory medications, modality use, coccygectomy, and fluoroscopically guided steroid injections. There are no studies documenting the efficacy of fluoroscopically guided coccygeal steroid injections in patients with coccydynia.
Methods: Retrospective chart review was used to collect data on 14 consecutive patients diagnosed with coccydynia who underwent a fluoroscopically guided coccygeal
injection of 80 mg triamcinolone acetate and 2mg of 1% lidocaine over a 3-year period at a tertiary care academic medical center.
Results: Using stepwise logistic regression, acute pain was determined to be the
best predictor of relief. Fisher’s exact test showed that those patients with pain lasting less then 6 months were significantly more likely to have greater than 50% relief
(P=0.055). Patients with chronic pain longer than 6 months were not found to have
pain relief of >50% to any statistical significance, but every patient with acute pain
showed improvement.
Conclusion: Patients with acute pain (less then 6 months) are more likely to respond
to fluoroscopically guided coccygeal steroid injections.
Key words: Coccydynia, steroid injection, fluroscopy.
Lumbar Facet Joint Nerve Blocks in
Managing Chronic Facet Joint Pain: One-Year
Follow-up of a Randomized, Double-Blind
Controlled Trial: Clinical Trial NCT00355914
Authors: Manchikanti Laxmaiah
Published: March 2021

Background: Lumbar facet joints have been implicated as the source of chronic pain in
15% to 45% of patients with chronic low back pain. Various therapeutic techniques including intraarticular injections, medial branch blocks, and radiofrequency neurotomy of lumbar facet joint nerves have been described in the alleviation of chronic low back pain of facet joint origin.
Objective: The study was conducted to determine the clinical effectiveness of therapeutic
local anesthetic lumbar facet joint nerve blocks with or without steroid in managing chronic
function-limiting low back pain of facet joint origin.
Design: A randomized, double-blind, controlled trial.
Setting: An interventional pain management setting in the United States.
Methods: This study included 60 patients in Group I with local anesthetic and 60 patients
in Group II with local anesthetic and steroid. The inclusion criteria was based on the positive response to the diagnostic controlled comparative local anesthetic lumbar facet joint
blocks.
Outcome measures: Numeric pain scores, Oswestry Disability Index, opioid intake, and
work status. All outcome assessments were performed at baseline, 3 months, 6 months,
and 12 months.
Results: Significant improvement with significant pain relief (> 50%) and functional improvement (> 40%) were observed in 82% and 85% in Group I, with significant pain relief
in over 82% of the patients and improvement in functional status in 78% of the patients.
Based on the results of the present study, it appears that patients may experience significant
pain relief 44 to 45 weeks of 1 year, requiring approximately 3 to 4 treatments with an average relief of 15 weeks per episode of treatment.
Conclusion: Therapeutic lumbar facet joint nerve blocks, with or without steroid, may provide a management option for chronic function-limiting low back pain of facet joint origin.
Key words: Chronic low back pain, lumbar facet or zygapophysial joint pain, facet joint
nerve or medial branch blocks, comparative controlled local anesthetic blocks, therapeutic
lumbar facet joint nerve blocks
Implanted Occipital Nerve Stimulators
Authors: Jasper Joseph F.
Published: March 2021

Background: Chronic headache represents a very significant public health and economic
issue. One treatment modality for chronic refractory headache involves the use of subcutaneous implanted neurostimulator leads in the occipital region. Varied types of headache etiologies including migraine, transformed migraine, chronic daily headache, cluster headache,
hemicrania continua, occipital neuralgia, and cervicogenic headache have been studied with
peripheral nerve field stimulation and found responsive to stimulation of the suboccipital region, known commonly as occipital nerve stimulation (ONS).
Objective: To evaluate the strength of evidence that occipital nerve stimulation is an effective treatment of benign headache.
Study Design: A systematic review of occipital nerve stimulation for the treatment of
chronic headache.
Methods: A systematic review of the literature through EMBASE and PubMed/Medline for
clinical studies was performed. The Agency for Healthcare Research and Quality (AHRQ) criteria was utilized to assess the evidence regarding occipital nerve stimulators and arrives at
conclusions as to their efficacy in the treatment of headache. Studies were also graded using AHRQ criteria. The overall body of evidence was then graded on a 5 level scale from Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited) to Level V (indeterminate).
Results: Ten observational studies, of which 4 were prospective, and a number of case series, case reports, and reviews were identified. No randomized controlled trials (RCT) were
identified. All of the articles reported positive outcomes including improved pain relief, reduced frequency, intensity, and duration of headaches with reduced medication consumption. ONS was reportedly successful for 70 – 100% of patients. Reduction of pain in patients
with occipital headaches and transformed migraine is significant and rapid; for cluster patients the improvement may be less dramatic and it may take several months of occipital
stimulation to achieve relief.
No long-term adverse events occurred. Several short-term incidents occurred including infection, lead displacement, and battery depletion. The body of evidence as a whole is a level of strength of IV, limited.
Conclusion: ONS is a useful tool in the treatment of chronic severe headaches with at least
Level IV (limited) evidence based on multiple positive studies.
Key Words: headache, chronic daily headache, occipital neuralgia, cervicogenic headache, migraine, transformed migraine, cluster headache, neuromodulation, neurostimulation, stimulator, peripheral nerve stimulation.
Opioid Antagonists, Partial Agonists, and
Agonists/Antagonists: The Role of OfficeBased Detoxification
Authors: Helm II Standiford
Published: March 2021

Background: The opioid receptor antagonists naloxone and naltrexone are competitive antagonists at the mu, kappa, and sigma receptors with a higher affinity for
the mu receptor and lacking any mu receptor efficacy. Buprenorphine is classified as
a partial agonist. It has a high affinity, but low efficacy at the mu receptor where it
yields a partial effect upon binding. It also, however, possesses kappa receptor antagonist activity making it useful not only as an analgesic, but also in opioid abuse deterrence, detoxification, and maintenance therapies. Naloxone is added to sublingual
buprenorphine (Suboxone®) to prevent the intravenous abuse of buprenorphine. The
same product (sublingual buprenorphine) when used alone (i.e. without naloxone) is
marketed as Subutex®.
Objective: To evaluate and update the available evidence regarding the use of agonist/antagonists to provide office-based opioid treatment for addiction.
Methods: A review using databases of EMBASE and MEDLINE (1992 to December
2007). These included systematic reviews, narrative reviews, prospective and retrospective studies, as well as cross-references from other articles.
Outcome Measures: The primary outcome measure was treatment retention. Other outcome measures included opioid-free urine drug testing, opioid craving, intensity of withdrawal, pain reduction, adverse effects, addiction severity index, and HIV
risk behavior.
Results: The results found 17 studies, 1 systematic review, 12 RCTs, and 4 observational series, which document the efficacy and safety of buprenorphine alone and
in combination with naloxone in detoxifying and maintaining abstinence from illicit
drugs in patients with opioid addiction.
Conclusion: Based on the present evaluation, it appears that opioid antagonists,
partial agonists, and antagonists are useful in office-based opioid treatment for addiction.
Key words: Opioid, antagonist, partial agonist, tolerance, dependence, detoxification, withdrawal, hyperalgesia, buprenorphine, naloxone, naltrexone, methylnaltrexone, butorphanol, nalbuphine, pentazocine
Percutaneous Occipital Stimulator Lead Tip
Erosion: Report of 2 Cases
Authors: Trentman Dr. Terrence L.
Published: March 2021

Occipital nerve stimulation is an emerging treatment modality for refractory headache disorders like migraine and cluster headache. Either percutaneous or surgical leads are implanted subcutaneously in the occipital
region in an effort to stimulate the distal branches of the occipital nerves
(C2-3). A number of complications of this technique have been reported, such as painful direct muscle stimulation and lead migration.
We report the first 2 cases of occipital lead erosion. In both cases, the
lead erosion occurred many months after implantation. One patient lost
a significant amount of weight between the time of implant and lead
erosion, while the other patient had no obvious risk factors. One patient underwent lead removal with reimplantation 1 month later; the
other was managed with excision of a granuloma at the erosion site
and prophylactic antibiotics. Both patients returned to excellent headache control.
Lead erosion is a possible complication of occipital stimulation; strategies
to reduce the risk of lead erosion are discussed, although further studies
are needed to clarify the best surgical techniques.
Key words: Headache, occipital stimulation, migraine, cluster headache
Sclerotherapy of Baker’s Cyst with Imaging
Confirmation of Resolution
Authors: Centeno Christopher J.
Published: March 2021

Background: Baker’s cysts are commonly encountered in pain management
practices.
Objective: To ascertain if sclerotherapy treatment of a Baker’s cyst could produce
objectively verifiable MRI imaging changes.
Design: Case report.
Methods: A 52-year-old white male with a posterior horn of the medial meniscus tear and a large Baker’s cyst who had failed conservative care and drainage
was imaged before treatment with sclerosing. Three injections of 12.5% dextrose
and anesthetic with sodium morrhuate were injected intraarticular into the right
knee after drainage.
Results: The Baker’s cyst resolved on both postoperative imaging after the completion of care as well as on physical examination.
Conclusions: Prolotherapy in this case study seemed to be an effective treatment for Baker’s cyst in this patient.
Key words: sclerosing, Baker’s cyst, knee, sclerotherapy, sodium morrhuate,
dextrose
Accuracy of MRI for Diagnosis of
Discogenic Pain
Authors: O’Neill Conor
Published: March 2021

Background: Previous studies have compared MRI parameters to the results from discography. However, none have evaluated the overall diagnostic performance of MRI, taking into
account that many MRI characteristics may be correlated.
Objective: Determine the accuracy of MRI for diagnosis of discogenic pain, taking into
consideration the interdependence of MRI parameters.
Study Design: An observational report.
Setting: Sample of 143 patients, 92 male and 51 female in a spinal pain speciality center. Discography classification and scorings for MRI parameters were collected as outcome measures.
Methods: MRI and discography data were collected from patients with chronic low back
pain. Five MRI characteristics were defined: high intensity zone, nuclear signal, disc height,
disc contour, and bone marrow intensity change. On discography, each disc was classified
as either positive or negative. The accuracy of MRI was evaluated using receiver operating
characteristic curves.
Results: MRI parameters are correlated with each other and with discography findings,
and these correlations affect the accuracy of MRI. Overall, nuclear signal alone is as accurate as any of the other MRI parameters, or combination of parameters, in the diagnosis of
discogenic pain. While there is no difference in overall accuracy between nuclear signal and
the other MRI parameters, these parameters do influence test performance when there is a
moderate loss of nuclear signal . Moderate loss of nuclear signal and disc bulge has the best
combination of sensitivity (79.8%) and specificity (79.3%). Adding moderate loss of disc
height improves specificity (82.0%) slightly, and decreases sensitivity (73.6%) slightly, while
incorporating high intensity zone grade II further improves specificity (92.6%) and decreases sensitivity (54.7%). High intensity zone grade I and bone marrow intensity change have
minimal influence, even when there is moderate loss of nuclear signal.
Conclusions: MRI parameters are correlated with each other and with discography findings, influencing the diagnostic performance of MRI. Combining MRI parameters improves
the diagnostic performance of MRI, but only in the presence of moderate loss of nuclear signal. When there is either normal nuclear signal or severe loss of nuclear signal the other MRI
parameters have no influence on test performance. The practical implication for physicians
that use discography is that the most important single MRI parameter to consider is nuclear
signal. If nuclear signal is normal the disc is very likely to be negative on discography, while
if there is severe loss of nuclear signal it is very likely to be positive. Discography will be most
useful in discs with moderate loss of nuclear signal, particularly if there are no other MRI abnormalities present.
Key words: Discography, MRI, ROC curve, chronic back pain, neural signal, disc contour,
high intensity zone
Efficacy of Transverse Tripolar Spinal Cord
Stimulator for the Relief of Chronic Low
Back Pain from Failed Back Surgery
Authors: Buvanendran Asokumar
Published: March 2021

Background: Failed back surgery syndrome is a common clinical entity for which spinal
cord stimulation has been found to be an effective mode of analgesia, but with variable success rates.
Objective: To determine if focal stimulation of the dorsal columns with a transverse tripolar lead might achieve deeper penetration of the electrical stimulus into the spinal cord and
therefore provide greater analgesia to the back.
Design: Case report.
Methods: We describe a 42-year-old female with failed back surgery syndrome that had
greater back pain than leg pain. The tripolar lead configuration was achieved by placing percutaneously an octapolar lead in the spinal midline followed by 2 adjacent quadripolar leads,
advanced to the T7-T10 vertebral bodies.
Results: Tripolar stimulation pattern resulted in more than 70% pain relief in this patient
during the screening trial, while stimulation of one or 2 electrodes only provided 20% pain
relief. After implantation of a permanent tripolar electrode system with a single rechargeable
battery, the pain relief was maintained for one year.
Conclusion: This is case report describing a case of a patient with chronic low back pain
with a diagnosis of failed back surgery syndrome in which transverse tripolar stimulation using an octapolar and 2 quadripolar leads appeared to be beneficial. The transverse tripolar
system consists of a central cathode surrounded by anodes, using 3 leads. This arrangement
may contribute to maximum dorsal column stimulation with minimal dorsal root stimulation
and provide analgesia to the lower back.
Key words: Epidural, low back pain, spinal cord stimulation, failed back surgery syndrome,
tripolar stimulation
Ketamine Treatment for Intractable Pain in
a Patient with Severe Refractory Complex
Regional Pain Syndrome: A Case Report
Authors: Schulz Paul E.
Published: March 2021

In this case report, we describe the effect of ketamine infusion in a case of
severe refractory complex regional pain syndrome I (CRPS I). The patient was
initially diagnosed with CRPS I in her right upper extremity. Over the next 6
years, CRPS was consecutively diagnosed in her thoracic region, left upper extremity, and both lower extremities. The severity of her pain, combined with
the extensive areas afflicted by CRPS, caused traumatic emotional problems
for this patient. Conventional treatments, including anticonvulsants, bisphosphonates, oral steroids and opioids, topical creams, dorsal column spinal cord
stimulation, spinal morphine infusion, sympathetic ganglion block, and sympathectomy, failed to provide long-term relief from pain. An N-methyl-d-aspartate (NMDA) antagonist inhibitor, ketamine, was recently suggested to be
effective at resolving intractable pain. The patient was then given several infusions of intravenous ketamine. After the third infusion, the edema, discoloration, and temperature of the affected areas normalized. The patient became
completely pain-free. At one-year of follow-up, the patient reported that she
has not experienced any pain since the last ketamine infusion.
Treatment with intravenous ketamine appeared to be effective in completely
resolving intractable pain caused by severe refractory CRPS I. Future research
on this treatment is needed.
Key words: Ketamine, Complex Regional Pain Syndrome (CRPS), treatment
Intrathecal Granuloma in a Patient Receiving
High Dose Hydromorphone
Authors: Grider Jay S.
Published: March 2021

Intrathecal granuloma formation has commonly been described with morphine
therapy. It has been suggested that a high concentration of intrathecal morphine
may be responsible for this complication. Much less commonly, intrathecal hydromorphone has been associated with intrathecal granuloma formation.
In the current case we report the evaluation and management of an intrathecal
granuloma in a patient receiving a relatively high concentration of intrathecal hydromorphone.
A nonsurgical, conservative approach to management involves stopping the infusion and observing the patient for improvement as the granuloma mass often
slowly resolves once the infusion is stopped. Cessation of the infusion or addition
of clonidine to the IDDS admixture in conjunction with close clinical monitoring
may be reasonable treatment options in patients with an asymptomatic or mildly
symptomatic inflammatory mass. In the current study, rapidly declining neurologic function with a confirmed inflammatory mass adherent to the spinal canal necessitated urgent surgical intervention.
Though use of intrathecal hydromorphone still represents an off label application,
this opiate is commonly employed as an alternative first line analgesic agent. This
case report highlights the potential of high-dose and high infusate concentration
intrathecal hydromorphone to form an inflammatory granuloma.
Key words: Intrathecal hydromorphone, intrathecal granuloma, inflamatory
mass, intraspinal drug delivery
Ultrasound-Guided Sacroiliac Joint
Injection Technique
Authors: Harmon Professor Dominic
Published: March 2021

We describe a case report and technique for using a portable ultrasound scanner
and a curvilinear transducer (4-5MHz) (SonoSite Micromaxx SonoSite, Inc. 21919
30th Drive SE Bothwell W. A.) to guide sacroiliac joint (SIJ) injection.
A 42-year-old male presented with chronic lower back pain centered on his left SIJ.
His pain averaged 7 out of 10 (numerical rating scale). For the ultrasound-guided
SIJ injection the patient was placed in the prone position. The ultrasound transducer was oriented in a transverse orientation at the level of the sacral hiatus. Here the
sacral cornuae were identified. Moving the transducer laterally from here, the lateral edge of the sacrum was identified. This bony edge was followed in a cephalad direction with the transducer maintained in a transverse orientation. A second
bony contour, the ileum, was identified. The cleft between both bony contours represented the sacroiliac joint. This was found at 4.5 cm depth. Real-time imaging
was used to direct a 22G spinal needle into the SIJ, where solution was injected under direct vision.
The patient’s pain intensity decreased to a 2 out of 10 (numerical rating scale). Function improved and the patient was able to return to work. These improvements
were maintained at 16 weeks. Ultrasound guidance does not expose patients and
personnel to radiation and is readily accessible.
Ultrasound-guided SIJ injections may have particular applications in the management of chronic lower back pain in certain clinical scenarios (e.g. pregnancy). Future
studies to demonstrate efficacy and reproducibility are needed.
Key words: Technique, visualization, real-time, ultrasound, sacroiliac joint.
Fluoroscopically-Guided Injections to Treat
“Kissing Spine” Disease
Authors: Lamer Tim
Published: March 2021

Background: Any spine structure that is innervated by afferent nociceptive nerve fibers
is a potential pain generator. In the lumbar spine, the most studied pain generators include: sacroiliac joints, the zygapophysial joints, the intervertebral discs, myofascial structures. Anomalous lumbosacral articulations, the spinous processes, and lumbar spine osteophytes are less commonly reported.
Objective: To describe the diagnostic and therapeutic features of “kissing spine” disease or Baastrup’s Sign with particular attention to MRI findings and fluoroscopicallyguided injection therapy.
Design: A series of 3 patients with axial low back pain presented with exam findings
and MRI changes suggestive of pain emanating from adjacent spinous processes that appeared to be in direct contact or very closely opposed. This has been described in the literature as “kissing spine” disease or Baastrup’s sign. Fluoroscopically-guided injections
were performed and the responses were studied.
Results: The 3 patients had MRI findings consisting of inflammation and/or edema in
the spinous processes and surrounding soft tissues. Fluoroscopically-guided injections
provided pain relief in all 3 patients. One patient with recurrent pain eventually underwent successful surgical resection of the involved spinous processes.
Conclusion: Painful adjacent and closely opposed spinous processes can be a source of
axial low back pain. We have described MRI features and the responses to fluoroscopically-guided injections in 3 patients with this condition.
Key words: Baastrup’s, kissing spine, spine injection
Pulsed Radiofrequency of Lumbar Dorsal Root
Ganglia for Chronic Post-Amputation Stump
Pain
Authors: Simopoulos Thomas
Published: March 2021

Background: Chronic pain following limb amputations is now a recognized chronic pain syndrome usually described in a combination of phantom and stump pain.
Both stump and phantom pain continue to be significant treatment challenges. If
pharmacotherapy does not provide effective analgesia for stump pain, a clinician
has interventional options that frequently give only transient benefit, or have a high
chance of failure in the long run.
Methods: We selected 2 patients with primarily stump pain and difficulty tolerating the limb prosthesis. After a positive response to segmental nerve root blocks at
L4 and L5, pulsed radiofrequency (PRF) was performed to the dorsal root ganglia
(DRG).
Results: Both patients experienced 50% pain relief or better for 6 months. Each patient tolerated the prosthetic limb and could function at a higher level.
Conclusion: PRF treatment of the DRG at the L4 and L5 nerve root level may be a
therapeutic option for patients with peripherally mediated intractable stump pain. A
decrease in pain intensity and improved toleration of the limb prosthesis was appreciated in both patients.
Key words: Stump pain, dorsal root ganglia, pulsed radiofrequency
Texas Spine and Joint Hospital,
Tyler, TX
Authors: Sorokin Andrea
Published: March 2021

Background: Subdural migration of epidural catheters is well known and documented. Subdural placement of intrathecal catheters has not been recognized. Two
cases of sudural placement of intrathecal catheters are presented.
Objective: The possibility of subdural migration of epidural catheters and its manifestations has been well documented. The following 2 cases demonstrate that intrathecal catheters can enter the subdural space upon placement.
Case Reports: The first case is a 52-year-old male with multiple sclerosis receiving a pump for intrathecal baclofen. It worked well for 10 years, but after 2 months
of inadequate relief despite a 2-fold increase in baclofen, the catheter was imaged.
The catheter pierced the arachnoid in the lower thoracic spine and tunneled subdural. It then pierced the arachnoid again, re-entering the cerebrospinal fluid (CSF) in
the cephalad portion of the thoracic spine. Over time, the tip became covered with
tissue, preventing direct CSF communication and causing subdural drug sequestration.
The second case is a 54-year-old male with chronic bilateral lower extremity pain having a pump placed for pain control. Because of inadequate relief after implantation,
the catheter was imaged. It pierced the arachnoid at L4-L5 but became subdural at
T12-L1. At the time of surgical revision, the catheter was pulled back to L2. Repeat
imaging showed it to be entirely subarachnoid, and analgesia was restored.
Conclusions: These cases differ from others in the literature because the catheter
was apparently subdural at the time of initial implantation. As these 2 cases demonstrate, this placement may manifest immediately, but it may remain undetected for a
prolonged period. Initial subdural placement should be considered along with catheter migration into the subdural space in the differential of a malfunctioning pump.
Key words: intrathecal catheter, subdural, migration
Preliminary Results of a Randomized,
Equivalence Trial of Fluoroscopic Caudal
Epidural Injections in Managing Chronic Low
Back Pain: Part 1 — Discogenic Pain without Disc
Herniation or Radiculitis
Authors: Manchikanti Laxmaiah
Published: March 2021

Background: Intervertebral discs, facet joints, ligaments, fascia, muscles, and nerve root dura
have been described as tissues capable of transmitting pain in the low back. The pathophysiology
of spinal radicular pain is the subject of ongoing research and controversy with discogenic pain
assuming a major role as a cause of non-specific low back pain. Even though epidural injections
are frequently administered in managing axial low back pain, the evidence is lacking.
Study Design: A randomized, double-blind, equivalence trial.
Setting: An interventional pain management practice, a specialty referral center, a private practice setting in the United States.
Objectives: To evaluate the effectiveness of caudal epidural injections with or without steroids in
managing chronic low back pain without disc herniation or radiculitis in providing effective and longlasting pain relief and to evaluate the differences between local anesthetic with or without steroids.
Methods: Patients were randomly assigned to one of 2 groups, Group I patients received caudal epidural injections with local anesthetic (lidocaine 0.5%), whereas Group II patients received
caudal epidural injections with 0.5% lidocaine 9 mL mixed with 1 mL of steroid.
Randomization was performed by computer-generated random allocation sequence by simple
randomization.
Outcomes Assessment: Multiple outcome measures were utilized which included the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid
intake with assessment at 3 months, 6 months, and 12 months post-treatment.
Significant pain relief was defined as 50% or more, whereas significant improvement in disability
score was defined as reduction of 40% or more.
Results: Significant pain relief (≥ 50%) was demonstrated in 72% to 81% of patients and functional status improvement was demonstrated by a reduction of 40% in the ODI scores in 81% of
the patients. The overall average procedures per year were 3.6 ± 1.05 in Group I and 3.9 ± 1.33 in
Group II with an average total relief per year of 32.3 ± 16.93 weeks in Group I and 30.7 ± 17.94
weeks in Group II over a period of 52 weeks.
Limitations: The results of this study are limited by lack of a placebo group and a preliminary
report of 36 patients in each group.
Conclusion: Caudal epidural injections with or without steroids may be effective in patients
with chronic function-limiting low back pain without facet joint pain, disc herniation, and/or radiculitis in over 70% of the patients.
Key words: Chronic low back pain, caudal epidural injections, discogenic pain, disc herniation, radiculitis, local anesthetic, steroids, controlled comparative local anesthetic blocks, provocation discography