bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of Complex Regional Pain
Syndrome in a Cohort of Multiple
Sclerosis Patients
Authors: Schwartzman Robert. J.
Published: March 2021

Background: More than 50% of multiple sclerosis patients experience chronic pain syndrome. We set out to determine the specific type
of chronic pain that was seen in our multiple sclerosis patients.
Methods: Patients with multiple sclerosis were catalogued between
January 2002 and April 2006 and identified by a search of the database. Only MS patients that met the 2005 revised McDonald criteria
were included.
Results: We determined the prevalence rate of complex regional
pain syndrome in a cohort of multiple sclerosis patients. In our sample
of 205 multiple sclerosis patients, the prevalence of complex regional
pain syndrome was 4 cases per 205 compared to an expected age and
sex-adjusted total prevalence of 0.078 cases per 205 (p < 0.0001).
Conclusion: This study suggests that multiple sclerosis patients are
at a higher risk of developing complex regional pain syndrome than
the general population.
Key words: Multiple sclerosis, complex regional pain syndrome,
prevalence
Response to Pulsed and Continuous
Radiofrequency Lesioning of the Dorsal Root
Ganglion and Segmental Nerves in Patients
with Chronic Lumbar Radicular Pain
Authors: Simopoulos Thomas T.
Published: March 2021

Objectives: We aimed to prospectively evaluate the response and safety of
pulsed and continuous radiofrequecy lesioning of the dorsal root ganglion/segmental nerves in patients with chronic lumbosacral radicular pain.
Methods: Seventy-six patients with chronic lumbosacral radicular pain refractory to conventional therapy met the inclusion criteria and were randomly assigned to one of 2 types of treatment, pulsed radiofrequency lesioning of the
dorsal root ganglion/segmental nerve or pulsed radiofrequency followed immediately by continuous radiofrequency. Patients were carefully evaluated for neurologic deficits and side effects. The response was evaluated at 2 months and
was then tracked monthly. A Kaplan-Meier analysis was used to illustrate the
probability of success over time and a Box-Whisker analysis was applied to determine the mean duration of a successful analgesic effect.
Results: Two months after undergoing radiofrequency treatment, 70% of the
patients treated with pulsed radiofrequency and 82% treated with pulsed and
continuous radiofrequency had a successful reduction in pain intensity. The average duration of successful analgesic response was 3.18 months (± 2.81) in
the group treated with pulsed radiofrequency and 4.39 months (±3.50) in those
patients treated with pulsed and continuous radiofrequency lesioning. A Kaplan-Meier analysis illustrated that in both treatment groups the chance of success approached 50% in each group at 3 months. The vast majority of patients
had lost any beneficial effects by 8 months. There was no statistical difference
between the 2 treatment groups. No side effects or neurological deficits were
found in either group.
Conclusion: Pulsed mode radiofrequency of the dorsal root ganglion of segmental nerves appears to be a safe treatment for chronic lumbosacral radicular
pain. A significant number of patients can derive at least a short-term benefit.
The addition of heat via continuous radiofrequency does not offer a significant
advantage. A randomized controlled trial is now required to determine the effectiveness of pulsed radiofrequency.
Key words: Pulsed radiofrequency lesioning, dorsal root ganglion, segmental
nerve, continuous radiofrequency lesioning, chronic lumbosacral radicular pain
Combination Opioid Analgesics
Authors: Smith Howard
Published: March 2021

Although there is no “ideal analgesic,” scientists and clinicians alike continue to search for
compounds with qualities which may approach the “ideal analgesic.” Characteristics of an
“ideal” analgesic may include: the agent is a full agonist providing optimal/maximal analgesia for a wide range/variety of pain states (e.g., broad spectrum analgesic activity), it does
not exhibit tolerance, it produces no unwanted effects and minimal adverse effects, it has
no addictive potential, it does not facilitate pain/hyperalgesia, it has a long duration, it has
high oral bioavailability, it is not vulnerable to important drug interactions, it is not significantly bound to plasma proteins, it has no active metabolites, it has linear kinetics, and it is
eliminated partly by hydrolysis to an inactive metabolite (without involvement of oxidative
and conjugative enzymes). Investigators have concentrated on ways to alter existing analgesics or to combine existing analgesic compounds with compounds which may improve efficacy over time or minimize adverse effects. The addition of an analgesic with a second agent
(which may or may not also be an analgesic) to achieve a “combination analgesic” is a concept which has been exploited for many years. Although there may be many reasons to add
2 agents together in efforts to achieve analgesia, for purposes of this article — reasons for
combining an opioid with a second agent to produce a combination opioid analgesic may
be classified into 6 major categories: 1.) combinations to prolong analgesic duration; 2.)
combinations to enhance or optimize analgesic efficacy (e.g., analgesic synergy); 3.) combinations to diminish or minimize adverse effects; 4.) combinations to diminish opioid effects
which are not beneficial (or contrariwise to or enhance beneficial opioid effects); 5.) combinations to reduce opioid tolerance/opioid-induced hyperalgesia; and 6.) combinations to
combat dependency issues/addiction potential/craving sensations. Combination opioid analgesics are one avenue which may give rise to “pain pills” with improved analgesic profiles
over existing analgesic medications.
Key words: Pain, combination opioid analgesic, tolerance, opioid-induced hyperalgesia
Ultrasound-Guided Interventional Procedures
for Patients with Chronic Pelvic Pain — A
Description of Techniques and Review of
Literature
Authors: Peng Philip W.H.
Published: March 2021

Chronic pelvic pain can present in various pain syndromes. In particular, interventional procedure plays an important diagnostic and therapeutic role in 3 types of pelvic pain syndromes:
pudendal neuralgia, piriformis syndrome, and “border nerve” syndrome (ilioinguinal, iliohypogastric, and genitofemoral nerve neuropathy). The objective of this review is to discuss
the ultrasound-guided approach of the interventional procedures commonly used for these
3 specific chronic pelvic pain syndromes.
Piriformis syndrome is an uncommon cause of buttock and leg pain. Some treatment options include the injection of the piriformis muscle with local anesthetic and steroids or the
injection of botulinum toxin. Various techniques for piriformis muscle injection have been
described. CT scan and EMG-guidance are not widely available to interventional physicians,
while fluoroscopy exposes the performers to radiation risk. Ultrasound allows direct visualization and real-time injection of the piriformis muscle.
Chronic neuropathic pain arising from the lesion or dysfunction of the ilioinguinal nerve, iliohypograstric nerve, and genitofemoral nerve can be diagnosed and treated by injection to
the invloved nerves. However, the existing techniques are confusing and contradictory. Ultrasonography allows visualization of the nerves or the structures important in the identification of the nerves and provides the opportunities for real-time injections.
Pudendal neuralgia commonly presents as chronic debilitating pain in the penis, scrotum,
labia, perineum, or anorectal region. A pudendal nerve block is crucial for the diagnosis
and treatment of pudendal neuralgia. The pudendal nerve is located between the sacrospinous and sacrotuberous ligaments at the level of ischial spine. Ultrasonography, but not
the conventional fluoroscopy, allows visualization of the nerve and the surrounding landmark structures.
Ultrasound-guided techniques offer many advantages over the conventional techniques.
The ultrasound machine is portable and is more readily available to the pain specialist. It prevents patients and healthcare professionals from the exposure to radiation during the procedure. Because it allows the visualization of a wide variety of tissues, it potentially improves
the accuracy of the needle placement, as exemplified by various interventional procedures in
the pelvic regions aforementioned.
Key words: Pudendal nerve, piriformis muscle, ilioinguinal nerve, iliohypogastric nerve,
genitofemoral nerve, ultrasound
Clostridial Sacroiliitis in a Patient with Fecal
Incontinence: A Case Report and Review
of the Literature
Authors: Weingarten Toby N.
Published: March 2021

Introduction: Image-guided sacroiliac joint injections are frequently
employed for both diagnostic and therapeutic relief of low back pain.
Case Report: An 83-year-old male with chronic lumbrosacral pain previously responsive to right sacroliac joint injections presented for repeat
injection. His medical history included Parkinsonism and stool incontinence. Forty-two hours after the injection, he developed fever, dyspnea,
and crepitus on the right buttock and thigh. Surgical debridement was
recommended, but the family wished for comfort care only. The patient
died hours later. The autopsy revealed Gram positive bacilli consistent
with Clostridial myonecrosis.
Discussion: Pyogenic sacroiliitis is rare and usually occurs in the setting of trauma, drug abuse, or extraspinal infections. Joint infections with
Clostridium have been reported after traumatic events including puncture, surgery, and abrasions. Clostridium spores are resistant to chemical
preparations used for skin sterilization and require high heat for destruction. Possible practice guidelines with patients that are stool incontinent
include mechanical wash prior to sterile preparation and placement of an
occlusive sterile dressing after injection to prevent stool contamination of
the needle puncture site. As with all rare complications, large scale studies are needed to better identify risk factors to formulate practice management strategies.
Key words: Sacroiliac joint, sacroiliac joint injection, pyogenic sacroilitis, fecal incontinence, clostridium
Confirmation of Needle Placement Within
the Piriformis Muscle of a Cadaveric
Specimen Using Anatomic Landmarks and
Fluoroscopic Guidance
Authors: Gonzalez Peter
Published: March 2021

Of patients presenting to pain clinics, complaints are of low back or buttock pain
with or without radicular leg symptoms is one of the most common. Piriformis
syndrome may be a contributor in up to 8% of these patients. The mainstay of
treatment is conservative management with physical therapy, anti-inflammatory medications, muscle relaxants, and correction of biomechanical abnormalities.
However, in recalcitrant cases, a piriformis injection of anesthetic and/or corticosteroids may be considered. Because of its small size, proximity to neurovascular
structures, and deep location, the piriformis muscle is often injected with the use
of commuted tomography (CT), magnetic resonance imaging (MRI), ultrasound
(US), fluoroscopy, electrical stimulators, or electromyography (EMG). Numerous
techniques have been proposed using one or a combination of the above modalities. However, application of these techniques is limited by unavailability of CT,
MRI, and EMG equipment as well as a paucity of trained physicians in US-guided
procedures in many pain treatment centers throughout the United States. Fluoroscopy, however, is more widely available in this setting.
This study utilized a cadaveric specimen to confirm proper needle placement for
piriformis or peri-sciatic injection utilizing the previously documented landmarks
for fluoroscopic guidance as described by Betts. An anteroposterior of the pelvis
with inclusion of the acetabular region of the hip and the inferior aspect of the
sacroiliac joint was obtained. The most superior-lateral aspect of the acetabulum
and the inferior aspect of the sacroiliac joint were identified. A marker was placed
one-third of the distance from the acetabular location to the inferior sacroiliac
joint, indicating the target location. A 22-gauge, 3.5-inch spinal needle was directed through the gluteal muscles to the target location using intermittent fluoroscopic guidance. The posterior ileum was contacted and the needle was withdrawn 1 –2 mm. This approach found the needle within the piriformis muscle
belly 2 –3 cm lateral to sciatic nerve. The present study was the first study, to our
knowledge, that has confirmed the intramuscular position of the needle within
the piriformis muscle of a cadaveric specimen using these anatomic landmarks
and fluoroscopic guidance.
Key words: piriformis syndrome, back pain, fluoroscopy, sciatica
Tension Pseudomeningocele Associated with
Retained Intrathecal Catheter: A Case Report
with a Review of Literature
Authors: Vodapally Mohan S.
Published: March 2021

Catheter related complications are not uncommon with permanently implanted intrathecal drug delivery systems. Pericatheter leak of cerebrospinal fluid
usually responds to conservative treatment.
We report a case of tension pseudomeningocele due to retained lumbar intrathecal catheter. It is essential to be aware of this rare complication and we recommend appropriate neurosurgical involvement in the management of pseudomeningocele to avoid potential and catastrophic complications.
This case presents one of the rare complications associated with the implantation of IDDS. If a patient with IDDS develops a complete fracture of the catheter at the spinal end, all attempts should be made to define the 2 ends of
the catheter and establish the continuity with a titanium connector. If the spinal end of the catheter is retracted deep into the interspinous ligaments and
not recoverable, avoid entering the intrethecal space at the same level. If a patient develops pseudomeningocele in the postoperative period of IDDS and
conservative methods including autologous epidural blood patch fail, we recommend an MRI of the spine for a detailed study along with prompt neurosurgical consultation.
Key words: Intrathecal catherer, retained, broken intrathecal catheter, pericatheter leak, lumbar swelling, psedomeningocele, duroplasty, ventriculoperitoneal shunt
Effectiveness of Thoracic Medial Branch Blocks
in Managing Chronic Pain: A Preliminary Report
of a Randomized, Double-Blind Controlled Trial;
Clinical Trial NCT00355706
Authors: Manchikanti Laxmaiah
Published: March 2021

Background: Thoracic facet joints have been implicated as the source of chronic pain in the
mid back or upper back in 34% to 48% of the patients. Various therapeutic techniques utilized
in managing chronic thoracic pain of facet joint origin include intraarticular injections, medial
branch blocks, and radiofrequency neurotomy of thoracic facet joint nerves.
Objective: To determine the clinical effectiveness of therapeutic local anesthetic medial branch
blocks with or without steroid in managing chronic function-limiting mid back or upper back pain
of facet joint origin.
Design: A randomized, double-blind, controlled trial.
Setting: An interventional pain management private practice, a tertiary referral center, in the
United States.
Methods: A total of 48 patients were included, with 24 patients in each of the local anesthetic
and steroid groups. All of the patients met the diagnostic criteria of thoracic facet joint pain by
means of comparative, controlled diagnostic blocks and the inclusion criteria. Group I patients received thoracic medial branch blocks with bupivacaine, whereas Group II patients received thoracic medial branch blocks with bupivacaine and non-particulate betamethasone.
Outcome Measures: Numeric pain scores (NRS), Oswestry Disability Index (ODI), opioid intake, and return to work status. All outcomes were assessed at baseline, 3 months, 6 months,
and 12 months. Significant pain relief was defined as > 50% pain relief. Significant functional improvement was defined as 40% reduction of ODI.
Results: In Group I, 79% of patients showed significant pain relief and functional improvement at 3 months, 6 months, and 12 months, a significant change from baseline. In Group II,
83%, 81%, and 79% of patients showed significant pain relief and functional improvement at
3 months, 6 months, and 12 months, a significant change from baseline. The majority of the patients experienced significant pain relief of 46 to 50 weeks, requiring approximately 3 to 4 treatments with an average relief of 16 weeks per episode of treatment.
Conclusion: The majority of the patients in both groups experienced significant pain relief and
improvement in functional status. Therapeutic thoracic medial branch blocks, with or without
steroid, may provide a management option for chronic function-limiting mid back or upper back
pain of facet joint origin.
Key words: Chronic spinal pain, thoracic pain, thoracic facet or zygapophysial joint pain, facet
joint nerve or medial branch blocks, comparative controlled local anesthetic blocks, therapeutic
thoracic medial branch blocks
The Biomechanics of the Lumbosacral Region
In Acute And Chronic Low Back Pain Patients
Authors: Nakipoglu Güldal Funda
Published: March 2021

Background: A previous study examined the relationship between the sacral inclination
angle (SIA), lumbosacral angle (LSA) and sacral horizontal angle (SHA) and spinal mobility in acute low back pain and chronic low back pain patients. We chose to investigate the
lumbar lordosis angle, segmental lumbar lordosis angle, SIA, LSA and SHA in acute and
chronic low back pain (LBP) patients as well as the correlation between spinal stability and
these angles.
Objectives: To investigate the biomechanics of the lumbosacral spine region in acute and
chronic LBP patients, as well as to examine the correlation between spinal stability and lumbosacral angles.
Study Design: Randomized controlled evaluation
Setting: Physical Medicine and Rehabilitation outpatient clinic
Methods: Sixty participants with LBP were recruited and categorized as either acute LBP
(pain < 3 months) or chronic LBP (pain > 6 months), with 30 subjects in each group. All subjects underwent standing, lateral lumbosacral x-rays, which were analyzed for lumbar stability, SIA, LSA, SHA, lumbar lordosis angle and segmental lumbar lordosis angles.
Results: The mean age of the ALBP subjects was 41.00 ± 11.63 (18 – 66) and that of the
chronic LBP subjects 49.26 ± 15.6 (22-74), with females comprising 50% of the acute LBP
group and 73.3% of the chronic LBP group. Lumbar stability was observed in 62.1% of
acute LBP patients and 36.8% of chronic LBP patients. A statistically significant difference
was found between the 2 groups in terms of age, gender, and lumbar stability. There was
no statistical difference regarding SIA, LSA, SHA, total and segmental lordosis angles between acute and chronic LBP patients (p>0.05).
Conclusion: We were unable to find a difference between the radiological values for the
shape of the SIA, LSA, SHA, and total and segmental lordosis as noted on screening x-ray
techniques regarding the occurrence of acute or chronic LBP, but a statistically significant
difference was found for lumbar stability. Further extensive studies are needed to examine
lumbar stability and its relationship between angles of lumbosacral region.
Key words: biomechanic, acute low back pain, chronic low back pain, lumbar stability,
lumbosacral, sacral, lumbar lordosis
Systematic Review of Lumbar Provocation
Discography in Asymptomatic Subjects
with a Meta-analysis of False-positive Rates
Authors: Wolfer Lee
Published: March 2021

Background: Lumbar provocation discography is a controversial diagnostic test. Currently, there is a concern that the test has an unacceptably high false-positive rate.
Study Design: Systematic review and meta-analysis.
Objective: To perform a systematic review of lumbar discography studies in asymptomatic subjects and discs with a meta-analysis of the specificity and false-positive rate
of lumbar discography.
Methods: A systematic review of the literature was conducted via a PUBMED search.
Studies were included/excluded according to modern discography practices. Study quality was scored using the Agency for Healthcare Research and Quality (AHRQ) instrument
for diagnostic accuracy. Specific data was extracted from studies and tabulated per published criteria and standards to determine the false-positive rates. A meta-analysis of
specificity was performed. Strength of evidence was rated according to the AHRQ U.S.
Preventive Services Task Force (USPSTF) criteria.
Results: Eleven studies were identified. Combining all extractable data, a false-positive
rate of 9.3% per patient and 6.0% per disc is obtained. Data pooled from asymptomatic subjects without low back pain or confounding factors, shows a false-positive rate of
3.0% per patient and 2.1% per disc. In data pooled from chronic pain patients, asymptomatic of low back pain, the false-positive rate is 5.6% per patient and 3.85% per disc.
Chronic pain does not appear to be a confounding factor in a chronic low back pain patient’s ability to distinguish between positive (pathologic) and negative (non-pathologic) discs. Among additional asymptomatic patient subgroups analyzed, the false-positive rate per patient and per disc is as follows: iliac crest pain 12.5% and 7.1%; chronic
neck pain 0%; somatization disorder 50% and 22.2%, and, post-discectomy 15% and
9.1%, respectively. In patients with chronic backache, no false-positive rate can be calculated. Low-pressure positive criteria (≤ 15 psi a.o.) can obtain a low false-positive rate.
Based on meta-analysis of the data, using the ISIS standard, discography has a specificity of 0.94 (95% CI 0.88 – 0.98) and a false-positive rate of 0.06.
Conclusions: Strength of evidence is level II-2 based on the Agency for Healthcare Research Quality (USPSTF) for the diagnostic accuracy of discography. Contrary to recently published studies, discography has a low false-positive rate for the diagnosis of discogenic pain.
Key words: Meta-analysis, lumbar discography, false-positive, asymptomatic subjects
Does Opioid Use for Pain Management Warrant
Routine Bone Mass Density Screening in Men?
Authors: Bailey Mrs. Gina M.
Published: March 2021

Background: Although opioids are known to inhibit testosterone production and bone formation, no prior study has investigated the relationship between opioid use in male subjects and
bone mass density measurements.
Method: Eighty-one male patients who had been using opioids for a period of time from a few
weeks to 20 years were included in this study. Blood samples were obtained to examine the total testosterone level of these subjects and each patient also had a bone mass density scan. This
study was done retrospectively using lab values collected during the normal care of the patient.
No extra measures were done relative to this study and all patient identifiers were removed from
the data prior to analysis. Accordingly, there was no need here for an IRB or patient consent.
Results: Fifty percent of hypogonadal men had bone mass densities in the osteoporotic or osteopenic range. Forty-two percent of the men who had total testosterone levels within the normal range also had bone mass densities within these ranges. Other factors may also influence
the bone mass density results. For example, in this study 52% of the patients disclosed that they
smoke.
Conclusion: Of this population almost half of the men had bone mass densities in the osteopenic/osteoporotic ranges, regardless of their total testosterone blood level. Therefore, monitoring
the total testosterone blood level is not a reliable method to determine the risk for developing
opioid-associated osteoporosis. Further investigations should be done to help evaluate whether
routine bone mass density screenings for men prescribed opioids for chronic pain management
may be warranted.
Key words: Opioid, OPIAD, hypogonadal, bone mass density
Use of Spinal Cord Stimulator for Treatment of
Lumbar Radiculopathy in a Patient with Severe
Kyphoscoliosis
Authors: Atallah Joseph
Published: March 2021

Spinal cord stimulation (SCS) has been a therapeutic option for chronic pain for
over 40 years with a common indication being failed back surgery syndrome
(FBSS). This case reports the successful implantation of a spinal cord stimulator in a patient with FBSS and kyphoscoliosis for treatment of radicular pain.
Technical considerations and anatomical difficulties that may be encountered
during placement with kyphoscoliosis will be discussed. This patient had failed
other therapies including oral medications, epidural steroid injections, spinal
surgeries, and physical and aquatic therapies. On physical examination the patient had a severely deformed lumbar spine. Careful review of the spine radiographs and CT scan revealed lead placement might be possible at the level of
T12-L1 or L1-2.
A Medline search did not reveal a case of kyphoscoliosis with radicular pain
treated with SCS. After a successful percutaneous trial, a SCS was implanted.
Fourteen weeks later, the patient reported being pain free with an increased
physical activity level and opioid discontinuation.
Technical considerations with kyphoscoliosis may discourage pain physicians
from attempting SCS. This case illustrates that with careful selection, some of
these patients may be candidates for SCS with good results.
Key words: Spinal cord stimulator, spinal cord stimulation, failed back surgery
syndrome, kyphoscoliosis, back pain, lumbar radiculopathy
Systematic Review of Thoracic Discography
as a Diagnostic Test for Chronic Spinal Pain
Authors: Singh Vijay
Published: March 2021

Background: Even though the prevalence of thoracic pain has been reported to be
15% of the general population and up to 22% of the population in interventional pain
management settings, the role of thoracic discs as a cause of chronic thoracic and extrathoracic pain has not been well researched. The intervertebral discs, zygapophysial or
facet joints, and other structures including the costovertebral and costotransverse joints
have been identified as a source of thoracic pain.
Objective: To systematically assess the quality of clinical studies evaluating the diagnostic accuracy of provocation thoracic discography.
Study Design: A systematic review of provocation thoracic discography.
Methods: A systematic review of the literature was performed to assess the diagnostic accuracy of thoracic discography with respect to chronic, function limiting, thoracic
or extrathoracic pain.
Studies meeting the Agency for Healthcare Research and Quality (AHRQ) methodologic
quality criteria with scores of 50 or higher were included for the assessment of the level
of evidence. Level of evidence was based on the United States Preventive Services Task
Force (USPSTF) criteria for the assessment of accuracy of diagnostic studies. Based on the
level of evidence, recommendations were made according to Guyatt et al’s criteria.
Results: The clinical value of thoracic provocation discography is limited (Level II-3) with
2C/weak recommendation derived from low quality or very low quality evidence indicating that other alternatives may be equally reasonable.
Conclusion: Based on the available evidence for this systematic review, thoracic provocation discography is provided with a weak recommendation for the diagnosis of discogenic pain in the thoracic spine, if conservative management has failed. This is qualified
by the need to appropriately evaluate and diagnose other causes of chronic thoracic pain
including pain originating from thoracic facet joints.
Key words: Thoracic pain, chest wall pain, intervertebral disc, thoracic intervertebral
disc, facet joint, thoracic disc herniation, discogenic pain, lumbar provocation discography, cervical provocation discography, thoracic provocation discography, false-positive response, diagnostic accuracy
Environmental Conditions and Performance
Outcomes: A Preliminary Report of Implications
for Patient Outcomes
Authors: Fortin Joseph D.
Published: March 2021

Background: Whereas a host of studies have established various forms of experimental bias, few clinical investigations have examined the relationship of
the behavior of the observer or examiner to a subject’s physical performance.
Objective: To measure the grip strength of volunteers in 2 distinct clinical
“environments.”
Methodology: Twenty subjects were randomized in a crossover design to
undergo grip strength testing in positive and negative environments as created by the distinctly different behavioral/communication approaches of the research staff. Each subject underwent 4 consecutive trials in both settings.
Results: A paired t- test was conducted to determine if the contrasting environments impacted the volunteer’s performance. Eight of the 10 subjects demonstrated a significantly stronger grip in the positive environment. One subject’s grip remained essentially unchanged and one subject provided a slightly
higher performance in the negative setting.
Conclusions: The study suggests that clinical environmental conditions influence the physical performance of a grip strength maneuver. Thus, it seems
probable that clinical or experimental settings may affect diagnostic test results
and/or functional outcome.
Key words: environment, improved outcomes, support, physicians’ attitudes
Intradiscal Electrothermal Therapy (IDET) for
the Treatment of Discogenic Low Back Pain:
Patient Selection and Indications for Use
Authors: Block Jon E.
Published: March 2021

Discogenic low back pain resulting from internal disc disruption can be severely disabling, clinically challenging, and expensive to treat. Previously, when conservative
care had been exhausted, open surgical intervention such as spinal fusion or artificial
disc replacement was the only treatment option for these patients. Intradiscal electrothermal therapy (IDET), a minimally-invasive technique performed in the outpatient
setting, offers an intermediate intervention between conservative care and surgery.
Specific selection criteria have been refined that identify patients for treatment with
IDET, ensuring maximal clinical benefit and appropriate use of healthcare resources.
Indications for use were developed from review of selection criteria from published
clinical reports and review articles of IDET, and further refined by identifying components with the strongest positive predictive value and by direct physician feedback.
Final indications for use consist of clinical and imaging criteria.
There are 5 compulsory indications for use: 1) persistent axial low back pain +/- leg
pain and non-responsive to ≥ 6 weeks of conservative care; 2) history consistent with
discogenic low back pain without marked lower extremity neurological deficit; 3) one
to 3 desiccated discs with or without small, contained herniated nucleus pulposus by
T2-weighted magnetic resonance imaging, with at least 50% remaining disc height;
4) concordant pain provocation by low pressure (< 50 psi above opening pressure)
discography; and, 5) posterior annular disruption by post-discography computed tomography. Using these patient selection characteristics, approximately 3 of 4 IDETtreated patients should achieve a minimal clinically important improvement in pain
and disability.
Key words: intradiscal electrothermal therapy, IDET, annuloplasty, back pain, disc
disruption
Unusual Cause of Back Pain in an Adolescent
Patient: A Case Report and Natural History of
Aggressive Vertebral Hemangioma in Children
Authors: Jha Bhawna
Published: March 2021

Back pain is an unusual complaint in children as compared to the adult population but is more likely to be pathological. We present a longitudinal study of
an 11-year-old patient who presented with a vertebral hemangioma which remained stable for a period of about 20 months followed by aggressive growth
resulting in spinal cord compression. This is only the fourth reported case of aggressive vertebral hemangioma in children; however, we document for the first
time the evolution of this lesion demonstrating a period of stability followed by
aggressive growth of the lesion.
We discuss the imaging differential diagnosis which includes asymptomatic vertebral hemangioma and malignant lesions. We also discuss different treatment
options available and their complications. In our patient, among the risk factors for an aggressive hemangioma, female gender and involvement of posterior elements were positive. However, the natural history of this lesion is not well
known in children. We need to study vertebral hemangioma further especially in
children to understand the natural course and help identify lesions which have
aggressive potential and prevent spinal cord compression. This will also help to
manage the lesion earlier with less aggressive therapies such as embolization
and ethanol injection rather than surgery.
Key words: back pain, pediatrics, vertebral hemangioma
Vertebral Osteomyelitis: A Potentially
Catastrophic Outcome after Lumbar Epidural
Steroid Injection
Authors: Simopoulos Thomas T.
Published: March 2021

Background and Objective: Epidural steroid injections are commonly used to
palliate the symptoms of spinal stenosis. Deep tissue infection is a known potential complication of these injections. There have been no previous published cases of osteomyelitis without epidural abscess after such injections. We present a
case in an elderly patient who presented only with persistent axial low back pain
following a lumbar epidural steroid injection (LESI). We emphasize early patient
evaluation, consideration of infectious predisposing factors, sterile technique, and
skin disinfectant.
Design: Open-label case report.
Case description: A 77-year-old diabetic male with a history of radicular pain
related to lumbar spinal stenosis was treated successfully several years prior with a
series of lumbar epidural steroid injections (LESI) and was re-treated with LESIs for
recurrent symptoms. Following his second epidural injection, he presented with
back pain and induration at the injection site without fever or neurological deficits.
Urgent magnetic resonance imaging (MRI) revealed a soft tissue abscess extending close to the epidural space around the corresponding L4/L5 vertebral level. The
patient recovered after incision and drainage of the abscess which was associated
with an osteomyelitis of the L4 and L5 vertebral spine. The causative organism was
methicillin-resistant Staphylococcus Aureus.
Conclusion: This case demonstrates that even with proper aseptic techniques,
immune-compromised patients who are colonized with an aggressive micro-organism may develop a potentially catastrophic infectious complication if subtle
persistent symptomatic complaints are not promptly and carefully evaluated.
Key words: osteomyelitis, epidural steroid injection, methicillin-resistant staphylococcus aureus (MRSA)
Pulsed Radiofrequency for Metastatic Pain
Treatment
Authors: Jasper Joseph F.
Published: March 2021

Background: Radiofrequency neurolysis is a common technique used in the treatment
of chronic pain, particularly facet (zygapophyseal joint) arthralgia. A needle-like cannula is insulated except for the exposed active tip, which is positioned as parallel and adjacent as possible to the targeted nerve branch. Via an inserted probe connected to a radiofrequency generator, energy flowing from the tip of the cannula creates a heat lesion
in the 80 – 85 degree Celsius range mostly about the length of the exposed active tip
and in proportion to the diameter of the probe. The common active tip lengths used for
neurolysis are 5mm or 10mm. The cannulae are FDA approved. The manufacturer advises physicians not to bend or otherwise modify a cannula prior to use. The cannulae are
available straight or bent, sharp and blunt.
The technique is guided under C-arm fluoroscopy. X-rays passing through the patient
demonstrate in 2 dimensions the projected relative radio-opaque bony landmarks and
the metallic cannula. Most currently available cannulae are uniform in their radio-opacity from tip to hub. The physician must make an educated guess as to the portion of the
cannula that will be making the lesion in relationship to the bony landmark.
Objective: A new radiofrequency cannula with a radio-opaque marker (ROC) delineates the proximal end of the active tip. The cannula was used in a phantom model. Images were reproduced with explanation of the potential advantage of the new device.
Result: The marker on the new cannula was visible and did help delineate the active
tip as well as its orientation. It was also helpful in making sequential lesions at the same
nerve using a “tip to tail” repositioning technique.
Conclusion: The ROC did represent an improvement over standard cannulae to optimize visualization of cannula and thus lesion placement using a phantom model. The
applications described were only for conventional or “hot” RF.
Key words: Anesthesiology, neurology, neurosurgery, physical medicine and rehabilitation, radiology, radiofrequency, neurolysis, rhizotomy
Peripherally-Acting Opioids
Authors: Smith Howard
Published: March 2021

Opioids are broad-spectrum analgesics with potent pain-relieving qualities but also
with potential adverse effects related to both short-term and long-term therapy. Researchers have attempted to alter existing opioid analgesics, utilize different routes/
formulations, or combine opioid analgesics with other compounds in efforts to improve analgesia while minimizing adverse effects. Exogenous opioids, administered
in efforts to achieve analgesia, work by mimicking the actions of endogenous opioids. Endogenous opioids and their receptors are located in the brain (supraspinal areas), spinal cord, and periphery. Although opioids and opioid receptors in the
brain and spinal cord have received much attention over many years, peripheral endogenous opioid analgesic systems have only been extensively studied during the
past decade. It has been known since 1990 that following injection into the rodent
hindpaw, d-Ala2
, N-Me-Phe4
, Gly5
-ol-enkephalin (DAMGO) [a muopioid receptor agonist] probably exerts its antinociceptive effects locally, since the doses administered
are too low to have an effect in the central nervous system (CNS). This notion has
been supported by the observation that the quaternary compound morphine methyliodide, which does not as readily cross the bloodbrain barrier and enter the CNS,
produced antinociception following intradermal administration into the hindpaw,
but not when the same dose was administered systemically (subcutaneously at a
distant site). With a growing appreciation of peripheral endogenous opioids, peripheral endogenous opioid receptors, and peripheral endogenous opioid analgesic
systems, investigators began growing hopeful that it may be possible to achieve adequate analgesics while avoiding unwanted central untoward adverse effects (e.g.
respiratory depression, somnolence, addiction). Peripherally-acting opioids, which
capitalize on peripheral endogenous opioid analgesic systems, may be one potential future strategy which may be utilized in efforts to achieve potent analgesia with
minimal side effects.
Key words: Pain, opioids, immune cells, peripherally-acting opioids (PAO), leukocytes, inflammatory pain, peripheral analgesia
Monitoring Opioid Adherence in Chronic
Pain Patients: Tools, Techniques, and Utility
Authors: Manchikanti Laxmaiah
Published: March 2021

Opioids are important, if not essential, agents in treating certain types of chronic pain. However, the prevalence of drug misuse, abuse, and addiction has fostered considerable consternation among physicians, who may hesitate to prescribe these medications both due to concern for patients (misuse, abuse, and
addiction), and fears of prosecution and/or professional sanction. Such practice may reflect
1) inadequate knowledge about patients’ susceptibility to, or current
drug misuse or abuse;
2) lack of familiarity with extant assessments and/or regulations,
and/or
3) an unanticipated reaction to existing guidelines, policies or laws.
We posit that assessing patients’ predisposition to, and patterns of, drug misuse/abuse is a vital first step toward establishing and maintaining the safe and
effective use of opioid analgesics in the treatment of chronic pain. Adherence
monitoring is critical to identify patients’ prior and current drug use, establish
treatment basis, and evaluate compliance, so as to avoid misuse and abuse,
and ensure sound and proper pain management.
This paper provides a review of the numerous monitoring approaches that
have been described in the literature and addresses the benefits and limitations
of these techniques and tools. The complex nature of the problem of drug misuse and abuse is discussed, and while no single monitoring technique can fully address this complex issue, we describe how multiple approaches to adherence monitoring may be employed to sustain the prudent use of opioids for
the treatment of chronic pain.
Key words: Opioids, adherence monitoring, drug abuse, non-compliance,
misuse, addiction, urine drug testing
Intrathecal Drug Delivery
Authors: Smith Howard
Published: March 2021

Intrathecal analgesia has emerged as a key therapeutic option for pain relief for
patients who have failed other treatment avenues as well as patients with adequate analgesia on high dose enteral or parenteral therapy but with unacceptable side effects. Intrethecal infusions of analgesics have been increasingly utilized since the later 1980s for the treatment of persistent pain.
The purpose of this review is to provide research based clinical insight regarding
the safe and appropriate use of the intrathecal infusion modality.
Long-term intrathecal infusion analgesia or long-term intrathecal or long-term
intrathecal analgesic therapy has significantly progressed over the past 25
years. The evidence for implantable intrathecal infusion systems is strong for
short-term improvement in pain of malignancy or neuropathic pain. The evidence is moderate for long-term management of persistent pain. Reasonably
strong evidence exists for the use of long-term intrathecal analgesic therapy in
alleviation of cancer pain; however, the evidence supporting long-term efficacy
in persistent noncancer pain is less convincing.
Future studies are needed to better define the role of long-term intrathecal analgesic therapy in persistent pain, especially with respect to which pain conditions or subpopulations of patients are most responsive to ong-term intrathecal
analgesic therapy, and which agents or combination of agents are most appropriate for which pain conditions or subpopulations of patients. Novel combinations of intrathecal analgesics such as clonidine and gabapentin deserve future study.
The current body of literature supports the use of intrathecal agents for the
treatment of moderate or severe pain related to cancer and noncancer origins.
Further clinical studies are needed to evaluate the efficacy and safety of new intrathecal drugs, the complications related to these devices, and the proper selection of patients to receive these treatments.
Key words: Intrathecal, morphine, baclofen, pump, implantable, infusion
Proton Pump Inhibitors and Pain
Authors: Smith Howard
Published: March 2021

There may be a relationship between proton pump inhibitors (PPIs) and iron absorption. PPIs
may decrease the amount of iron absorbed gastrointestinally specifically due to alteration of
the pH in the duodenum. Restless legs syndrome (RLS) is a sensorimotor disorder that includes
an urge to move legs, accompanied or caused by uncomfortable and unpleasant sensations
in the legs; the urge to move begins or worsens during periods of rest or inactivity, the urge
to move is partially or totally relieved by movement, and the urge is worse or only occurs at
night. In the majority of the restless leg syndrome population, the sensation is deep seated,
often described as being in the shin bones, and most commonly felt between the knee and
ankle. It may be described as a creepy, shock-like, tense, electric, buzzing, itchy, or even
numb sensation. A subpopulation of this restless leg syndrome patient population experiences
restless leg syndrome associated pain (RLSAP) that has been described as a deep “achy pain.”
This pain has not been found to be relieved by many of the typical over the counter analgesics.
Often, constant movement of the legs appears to be the only remedy, as these sensations
usually appear during periods of rest.
Furthermore, there appears to be an association between iron deficiency and those suffering
from Restless Leg Syndrome (RLS). The authors theorize that there may be a possible correlation
between PPIs and the symptoms (e.g. pain) associated with RLS. The authors propose that
PPIs, such as omeprazole, may interfere with iron absorption in certain patients and that a
subpopulation of patients who develop significant iron deficiency characterized by low serum
ferritin levels while on PPIs may also develop RLS-like symptoms (including RLSAP). While
there is no robust direct evidence to support any associations of PPIs and iron deficiency or
PPIs associated with RLS-like symptoms (including RLSAP), it is hoped that this manuscript may
spark research efforts on this issue.
Key words: Proton pump inhibitor (PPI), Restless Leg Syndrome (RLS), iron deficiency, pain,
iron absorption, Restless Leg Syndrome Associated Pain (RLSAP)
Thromboembolic Stroke: A Rare Complication
Associated with Peri-Procedural Management
of an Epidural Steroid Injection
Authors: Linn Andrew J.
Published: March 2021

Background: Little attention has been afforded to the potential adverse sequelae of withholding anticoagulation therapy in a patient after neuraxial interventions.
Objective: Presenting a case of thromboembolic stroke in a patient after holding warfarin
for a lumbar epidural steroid injection, previously unreported in published literature. The discussion that follows reviews the guidelines available to reduce the risk of thromboembolic
events in anticoagulated patients in the periprocedural period.
Case Report: An 81-year-old female with radicular pain secondary to spinal stenosis had
been seen on 5 previous occasions for lumbar epidural steroid injections. Prior to each procedure warfarin was held for 5–7 days with demonstrable reversal of anticoagulation to within the safe limits set for neuraxial techniques by the American Society of Regional Anesthesia
and Pain Medicine. On the morning following the sixth injection the patient was admitted to
the hospital for new onset slurred speech and left-sided hemiparesis.
A computed tomography scan established an acute, localized infarct in the distribution of the
right middle cerebral artery. Her symptoms were non-reversible and permanent.
Conclusions: Thromboembolism is a potentially devastating complication associated with
atrial fibrillation. Twenty percent of thromboembolic events in patients with atrial fibrillation
are fatal, and greater than 50% result in permanent disability. While thromboembolic events
following a brief period of normalization of coagulation for interventions appear rare, so is
the incidence of epidural hematomas. Considering the high mortality and permanent rate of
disability with thromboembolic events associated with atrial fibrillation, perhaps it is time to
balance our focus on the complications of withholding anticoagulation with those of bleeding.
Key words: Stroke, atrial fibrillation, epidural steroid injection complication, anticoagulation