bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Use of Intraoperative Dexmedetomidine
Infusion for Sedation During Spinal Cord
Stimulator Lead Placement via Surgical
Laminectomy
Authors: Harned Michael E.
Published: March 2021

Background: Spinal cord stimulators are most often placed through a percutaneous approach
using minimal sedation and local anesthesia to facilitate intraoperative testing. However, when
leads need to be placed using a laminectomy incision additional anesthesia is required which can
complicate intraoperative testing. There is no consensus as to the best anesthetic choice when
laminectomy-placed leads are required.
Objective: We present 2 cases where spinal cord stimulator leads were implanted through a
surgical laminectomy under sedation using dexmedetomidine infusion and local anesthesia to
provide a cooperative patient for intraoperative testing.
Case Report: Patient #1: A 40-year-old female with Complex Regional Pain Syndrome
secondary to an automobile accident who had good pain control with a spinal cord stimulator
until a lead fracture resulted in loss of stimulation. She required a laminectomy-placed lead
which was implanted under dexmedetomidine infusion and local anesthesia.
Patient #2: A 54-year-old female with Failed Back Syndrome who had good pain control until
a lead fracture resulted in loss of stimulation. She underwent a laminectomy-placed lead, new
battery pocket, and removal of the old system under a dexmedetomidine infusion and local
anesthesia.
Limitations: Report of only 2 cases.
Conclusions: The anesthetic management from a laminectomy-placed spinal cord stimulator
can present a difficult choice. A general anesthetic or even deep sedation can provide good
operative conditions but limits intraoperative testing or in the case of deep sedation risks
losing the airway in the prone position. On the other hand, minimal sedation, which facilitates
intraoperative testing, can make the surgical procedure extremely uncomfortable or even
unbearable. Dexmedetomidine infusion and local anesthesia provide sedation for the operative
portions while rendering the patient alert and cooperative during intraoperative testing.
Key words: Spinal Cord Stimulator, dexmedetomidine, percutaneous, laminectomy,
intraoperative, sedation
Center for Pain Relief, Inc, Charleston, West
Virginia
Authors: Dureja G.P.
Published: March 2021

Background: Post herpetic neuralgia is a chronic neuropathic pain syndrome which remains
one of the most difficult pain disorders to treat. Epidural injection of methylprednisolone
with or without local anesthetic provides relief for neuralgia for a short duration only. Recent
studies have shown a promising anti nociceptive effect for intrathecal midazolam, a water
soluble benzodiazepine, due to its interaction with benzodiazepine-GABA-A receptor complex
within the spinal cord.
Study Design: A randomized, double blind study was conducted at 2 different centers in
India.
Setting: Two different interventional pain practice centers in India.
Objectives: To quantify the effectiveness of a single intrathecal injection of midazolam
2 mg with and without epidural methylprednisolone 60 mg for management of pain and
allodynia in 150 adult patients with postherpetic neuralgia of 3-6 months duration involving
lumbosacral dermatomes.
Methods: Patients in Group M-0 (n=50) received epidural methylprednisolone (60 mg),
patients in group M-1 (n=50) received midazolam 2 mg in the intrathecal space while
patients in Group M-2 (n=50) received methylprednisolone (60 mg) in the epidural space plus
midazolam 2 mg in the intrathecal space.
Results: The administration of intrathecal midazolam (2 mg) provided short term improvement
in post herpetic neuralgia similar to epidural methylprednisolone. However, the combination
of intrathecal midazolam with epidural methylprednisolone resulted in prolonged duration
of analgesia in patients with post herpetic neuralgia. The need for analgesics was also
significantly less in patients who received the combination compared to those who received
either intrathecal midazolam or epidural methylprednisolone. No serious adverse effect was
reported with the use of intrathecal midazolam except a mild degree of sedation.
Conclusion: The combination of intrathecal midazolam with epidural methylprednisolone
resulted in prolonged duration of analgesia in patients with post herpetic neuralgia of
lumbosacral dermatomes due to the complementary anti nociceptive action of intrathecal
midazolam with epidural methylprednisolone on spinal nerve roots.
Limitations: The dose-response relationship of intrathecal midazolam was not evaluated in
our study, so further study should be conducted with different doses of intrathecal midazolam
for management of PHN.
Key words: postherpetic neuralgia, lumbosacral, midazolam, intrathecal, methylprednisolone,
epidural, pain, allodynia, sedation, neurological sequelae.
The Gel Box – a Testing Device for the
Characterization of Cryo- and Radiofrequency
Lesions Employed in Interventional Pain
Therapy
Authors: Birkenmaier Christof
Published: March 2021

Background: Radiofrequency (RF) and cryolesioning are established methods for the
therapeutic interruption of sensory nerve supply to facet joints and other painful musculoskeletal
structures. The varying clinical success rates of these treatments have – among other technical
issues – been attributed to the small size of these lesions combined with the limited precision
in placing them. Since there are 2 different physical methods for lesioning and a wide range
of probes and lesion generators available, it is likely that the lesions generated by them may
be of different size.
Objectives: We sought to devise an experimental setup that would allow for the
reproducible and comparable evaluation of the size of cryo and RF lesions as they are being
used in interventional pain therapy.
Methods: A wide range of potential media was evaluated for this purpose. Based on
technical specifications, as well as on preliminary testing, a specific agar agar gel with
a gel point of between 32o
C and 35o
C and a melting point of between 80o
C and 85o
C
was selected for these experiments. Two different testing containers were constructed
from transparent acrylic: one with a volume of 1,500 mL and the other with a volume of
12 mL. Each of them allows for the introduction of a cryo or a RF probe and 2 bundles
of thermoelements into the gel volume. A water bath was used to maintain the gels at
37o
C and bundled, ultrafine NiCr-Ni thermoelements type K were used for measuring
the isotherms. A series of RF and cryolesions were performed within these experimental
setups to evaluate their suitability for the comparative testing of cryo and RF probes and
generators.
Results: Both testing setups generated reproducible results and proved to be suitable for
measuring RF as well as cryolesions. Visual observation of the lesions was better with the
small testing container and rewarming / recooling after performing a cryo / RF lesion was
more rapid with the smaller gel volume.
Limitations: Our setup allows for the comparative measurement of RF and cryolesions, but
it cannot simulate the realities within living tissue. While convection as a confounding factor
was excluded by use of a gel, capillary perfusion and the specific characteristics of different
tissues cannot be simulated.
Conclusions: The testing setup described in this manuscript can serve for the comparative
and reproducible study of RF and cryolesions that are commonly used in interventional pain
therapy.
Key words: Radiofrequency lesioning, cryolesioning, interventional pain therapy,
experimental study, agar agar gel, thermoelement.
An Evaluation of the Diagnostic Accuracy
of Liquid Chromatography-Tandem Mass
Spectrometry Versus Immunoassay Drug
Testing in Pain Patients
Authors: West Cameron
Published: March 2021

Background: Immunoassay screening is used by pain physicians to determine compliance
with controlled substances. Because clinical use of pain medications is different from illicit drug
use, there is a need to evaluate the level of diagnostic accuracy of this procedure for the pain
patient.
Objective: To compare the results of automated screening by immunoassay with analysis by
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) in identifying pain patients using
illicit drugs and pain patients excreting low concentrations of their prescribed medications.
Study Design: A diagnostic accuracy study.
Methods: Urine samples from 4,200 pain patients were tested by immunoassay and LCMS/MS for the following drugs and metabolites: Amphetamine, Methamphetamine, Alphahydroxyalprazolam, Lorazepam, Nordiazepam, Oxazepam, Temazepam, Cannabinoids, Cocaine,
Methadone, Methadone Metabolite, Codeine, Hydrocodone, Hydromorphone, Morphine,
Propoxyphene, and Norpropoxyphene.
Results: In a number of patients negative immunoassay findings were superseded by positive
results on analysis by Mass Spectrometry. These were termed false negative results. The greatest
failures were for the benzodiazepines (28%) and for cocaine (50%).
Limitations: The study was limited by the lack of complete demographics for the cohort and
because only one immunoassay diagnostic product was used. It was also limited because not all
drugs react the same in the immunoassay.
Conclusions: We show that in general, immunoassay screening results are accurate, although
as shown in this study there are many false negative observations. The use of LC-MS/MS
technology significantly decreases the number of false negative results.
Key words: Drug abuse, illicit drug use, opioids, illicit drugs, benzodiazepines, false negatives,
liquid chromatography-mass spectrometry, immunoassay, adherence monitoring
The Use of Sub-Anesthetic Intravenous
Ketamine and Adjuvant Dexmedetomidine
when Treating Acute Pain from CRPS
Authors: Meenan Daniel R.
Published: March 2021

Complex regional pain syndrome (CRPS) is a pain condition of the extremities that
presents with pain and allodynia, decreased range of motion, swelling and skin
changes. There are 2 forms of CRPS — Type I which does not have demonstrable
nerve lesions and Type 2, which has evidence of obvious nerve damage. Management
of refractory CRPS has been challenging. Some studies have revealed that the Nmethyl-D-aspartic acid receptor (NMDAR) may be involved in the etiology of the pain
in CRPS and perhaps that a NMDA receptor antagonist like Ketamine is a potential
treatment for CRPS. However, the side effect profile of ketamine is concerning, and
limiting the adverse effects of the drug is beneficial. Dexmedetomidine is an alpha 2
agonist similar to clonidine with analgesic properties that can be used in combination
with ketamine to provide additional analgesia in CRPS.
This case describes the treatment of acute pain symptoms from Chronic Regional
Pain Syndrome-Type 1 (CRPS-1) with sub-anesthetic intravenous infusion of ketamine
with adjunct dexmedetomidine. A 47-year-old female patient presented with severe
pain, burning and allodynia from CRPS-1 refractory to conventional therapy. She was
then admitted to a monitored bed, received a sub-anesthetic intravenous infusion of
ketamine with adjunct dexmedetomidine for 19 hours and subsequently discharged
with complete resolution of her pain and associated symptoms. Here, the synergistic
effect of the ketamine and dexmedetomidine together is shown to provide excellent
symptom relief while decreasing the total ketamine administered. The combination
minimized unwanted side effects and eliminated the need for intensive care unit
admission secondary to anesthetic doses of ketamine.
Key words: CRPS; ketamine; dexmedetomidine; NMDA receptor; alpha 2 agonist;
analgesia.
Pharmacodynamic Profiles of Ketamine (R)-
and (S)- with 5-Day Inpatient Infusion for the
Treatment of Complex Regional Pain Syndrome
Authors: Goldberg Michael E.
Published: March 2021

Background: Ketamine might be effective in blocking central sensitization of pain
transmission neurons through its effect on NMDA receptors in refractory Complex Regional
Pain Syndrome (CRPS) patients. At higher doses, ketamine infusions can be associated with
significant risks; outpatient therapy requires return visits for a 10-day period with variable
efficacy and duration.
Objective: This study determined the efficacy of a 5-day moderate dose, continuous racemic
ketamine infusion. The pharmacodynamic responses to racemic ketamine and norketamine
were examined.
Design: Observational study
Methods: In this study, ketamine was titrated from 10-40 mg/hour in 16 CRPS patients, and
maintained for 5 days. Pain was assessed daily. Ketamine and norketamine concentrations
were obtained on Day 1 before starting the infusion; at 60 to 90 minutes, 120 to 150 minutes,
180 to 210 minutes, and 240 to 300 minutes after the initiation of the infusion on Days 2,
3, 4, and 5; and on Day 5 at 60 minutes after the conclusion of the infusion. The plasma
concentrations of (R)-ketamine, (S)-ketamine, (R)-norketamine and (S)-norketamine were
determined using an enantioselective liquid chromatography – mass spectrometry method.
Results: Ketamine and norketamine infusion rates stabilized 5 hours after the start of
the infusion. The subjects showed no evidence of significant tachycardia, arterial oxygen
desaturation, or hallucinatory responses. Subjects generally experienced minimal pain relief
on day one followed by significant relief by day 3. Mean pain scores decreased from the 8-9
to 3-5 ranges; however, the analgesic response to ketamine infusion was not uniform. On day
5, there was little or no change in the pain measure assessed as the worst pain experienced
over the last 24 hours in 37% of the subjects. (R)- and (S)-ketamine concentrations peaked
at 240-300 min. (R)- and (S)-norketamine concentrations were lower and peaked on Day 2
of the infusion, as opposed to Day 1 for (R)- and (S)-ketamine. Significant pain relief was
achieved by the second day of infusion and correlated with the maximum plasma levels of
ketamine and norketamine. Pain relief continued to significantly improve over the 5 day
infusion at concentrations of 200-225 ng/mL for (R)- and (S)-ketamine, and 90-120 ng/mL
for(R)- and (S)-norketamine.
Conclusions: A 5-day ketamine infusion for the treatment of severe CRPS provided
significant (P <0.05) pain relief by Day 3 compared to baseline. The pain relief experienced on
Day 2 of the infusion continued to improve over the 5-day infusion period and correlated with
the maximum plasma levels of ketamine and norketamine. We speculate that downstream
metabolites of ketamine and norketamine might be playing a role in its therapeutic efficacy.
Key words: ketamine, norketamine, CRPS, pharmacodynamics, chronic pain, enantiomers
he Role of Genomic Oxidative-Reductive
Balance as Predictor of Complex Regional Pain
Syndrome Development: A Novel Theory
Authors: Smith Howard
Published: March 2021

The aftermath of sequencing the human genome has birthed many efforts to utilize an
individual’s genetic information in order to tailor optimal treatment strategies — so-called
personalized medicine. An individual’s genetic information may eventually help diagnosis and
treatment, as well selecting optimal pharmacologic agents based partly on how well they reach
their target, how well they will bind to and produce an effect at their targets, how well they
will be metabolized, and the profile of their adverse effects. It also appears that clinicians may
be able to utilize an individual’s genetic information to ascertain a subject’s risk or susceptibility
of developing a particular medical condition. Although, this has not been widely utilized in
pain medicine at this point, the future may revolutionize the role of genetic information in the
evaluation and management of various pain conditions.
One reason for variations in therapeutic outcomes from different pharmacologic pain
treatments is the different genetic disposition of patient to develop pain or to respond to
analgesics. The patient’s phenotype may represent a conglomerate of several different genetic
variants concomitantly present in an individual. Genetic variants may modulate the risk of
developing a painful condition, or may modulate the perception of pain (e.g. OPRM1 or GCH1
variants conferring modest “protection” from pain by increasing the tone of the endogenous
opioid system or decreasing nitric oxide formation). Other genetic polymorphisms may alter
pharmacokinetic mechanisms (e.g. CYP2D6 related prodrug activation of codeine to morphine),
alter pharmacodynamic mechanisms (e.g. opioid receptor mutations), or alter other analgesic
effects (e.g. diminished euphoric effects from opioids potentially due to DRD2 polymorphisms
decreasing the functioning of the dopaminergic reward system).
This article theorizes that genetic alterations including functional polymorphisms of Nrf2 (a
master regulator of the transcription of multiple antioxidants) may render certain subjects more
or less susceptible to developing complex regional pain syndrome after surgery or trauma. If this
hypothesis is correct, knowing this information may translate into significant and “far-reaching”
effects on clinical decision-making surrounding the management of pain in patients who may
be more susceptible to develop complex regional pain syndrome. Furthermore, it could lead to
the development of novel prevention or intervention strategies, in efforts to prevent, abort, or
ameliorate the development of and/or effectively treat complex regional pain syndrome.
Key words: Complex regional pain syndrome (CRPS), single nucleotide polymorphism (SNPs),
Nrf2, antioxidant, oxidative stress, NQO1, ARE, NF-κB.
Cervical Epidural Injections in Chronic
Discogenic Neck Pain Without Disc Herniation
or Radiculitis: Preliminary Results of a
Randomized, Double-Blind, Controlled Trial
Authors: Manchikanti Laxmaiah
Published: March 2021

Background: Chronic neck pain is a common problem in the adult population with a typical 12-
month prevalence of 30% to 50%. However, there is a lack of consensus regarding the causes and
treatments of chronic neck pain.
Despite limited evidence, cervical epidural injections are one of the commonly performed nonsurgical interventions in the management of chronic neck pain.
Study Design: A randomized, double-blind, active control 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 cervical interlaminar epidural injections with local
anesthetic with or without steroids in the management of chronic neck pain with or without upper
extremity pain in patients without disc herniation or radiculitis or facet joint pain.
Methods: Patients without disc herniation or radiculitis and negative for facet joint pain by means
of controlled diagnostic medial branch blocks were randomly assigned to one of 2 groups: injection
of local anesthetic only or local anesthetic mixed with non-particulate betamethasone. Seventy
patients were included in this analysis. Randomization was performed by computer-generated
random allocation sequence by simple randomization.
Outcomes Assessment: Multiple outcome measures were utilized including the Numeric Rating
Scale (NRS), the Neck Disability Index (NDI), employment status, and opioid intake with assessment
at 3, 6, and 12 months post-treatment.
Significant pain relief or functional status was defined as a 50% or more reduction.
Results: Significant pain relief (≥ 50%) was demonstrated in 80% of patients in both groups and
functional status improvement (> 50%) in 69% of Group I and 80% of Group II. The overall average
procedures per year were 3.9 ± 1.01 in Group I and 3.9 ± 0.8 in Group II with an average total
relief per year of 40.3 ± 14.1 weeks in Group I and 42.1 ± 9.9 weeks in Group II over a period of
52 weeks in the successful group.
Limitations: The results of this study are limited by the lack of a placebo group and that it is a
preliminary report of 70 patients, with 35 patients in each group.
Conclusion: Cervical interlaminar epidural injections with local anesthetic with or without steroids
may be effective in patients with chronic function-limiting discogenic.
Key words: Chronic neck pain, cervical disc herniation, cervical discogenic pain, cervical epidural
injections, epidural steroids, local anesthetics
Facts, Fallacies, and Politics of Comparative
Effectiveness Research: Part 2 - Implications for
Interventional Pain Management
Authors: Manchikanti Laxmaiah
Published: March 2021

The United States leads the world in many measures of health care innovation.
However, it has been criticized to lag behind many developed nations in important
health outcomes including mortality rates and higher health care costs. The surveys
have shown the United States to outspend all other Organisation for Economic
Co-operation and Development (OECD) countries with spending on health goods
and services per person of $7,290 – almost 2½ times the average of all OECD
countries in 2007. Rising health care costs in the United States have been estimated
to increase to 19.1% of gross domestic product (GDP) or $4.4 trillion by 2018.
CER is defined as the generation and synthesis of evidence that compares the
benefits and harms of alternate methods to prevent, diagnose, treat, and monitor a
clinical condition or to improve the delivery of care. The, comparative effectiveness
research (CER) has been touted by supporters with high expectations to resolve most
ill effects of health care in the United States providing high quality, less expensive,
universal health care. The efforts of CER in the United States date back to the
late 1970s and it was officially inaugurated with the enactment of the Medicare
Modernization Act (MMA). It has been rejuvenated with the American Recovery and
Reinvestment Act (ARRA) of 2009 with an allocation of $1.1 billion.
CER has been the basis of decision for health care in many other countries. Of all the
available agencies, the National Institute for Health and Clinical Excellence (NICE)
of the United Kingdom is the most advanced, stable, and has provided significant
evidence, though based on rigid and proscriptive economic and clinical formulas.
While CER is taking a rapid surge in the United States, supporters and opponents
are emerging expressing their views. Since interventional pain management is a
new and evolving specialty, with ownership claimed by numerous organizations, at
times it is felt as if it has many fathers and other times it becomes an orphan. Part 2
of this comprehensive review will provide facts, fallacies, and politics of CER along
with discussion of potential outcomes, impact of CER on health care delivery, and
implications for interventional pain management in the United States.
Key words: Comparative effectiveness research, evidence-based medicine, Institute
of Medicine, National Institute for Health and Clinical Excellence, interventional pain
management, interventional techniques, geographic variations, inappropriate care.
Urine Drug Testing In Chronic Pain
Authors: Christo Paul J.
Published: March 2021

Therapeutic use, overuse, abuse, and diversion of controlled substances in
managing chronic non-cancer pain continue to be an issue for physicians and
patients. The challenge is to eliminate or significantly curtail abuse of controlled
prescription drugs while still assuring the proper treatment of those patients.
Some physicians are apprehensive regarding the use of chronic opioid therapy in
chronic non-cancer pain due to a perceived lack of proven evidence, the misuse of
opioids, tolerance, dependence, and hyperalgesia. However, others have criticized
the underuse of opioids, resulting in the undertreatment of pain. It has been the
convention that federal, state, and local governments; professional associations;
as well as pharmaceutical companies, physicians, accrediting bodies, medical
licensure boards, and the public all share responsibility for preventing abuse of
controlled prescription drugs.
To overcome the critical challenge of eliminating or significantly curtailing abuse
of controlled prescription drugs and at the same time assuring the appropriate
treatment for those patients who can be helped by these medications, it is crucial
to practice adherence or compliance monitoring of opioid therapy.
Compliance monitoring has been shown to be crucial in delivering proper opioid
therapy and preserving this therapy for the future. Urine drug testing (UDT) is
considered one of the mainstays of adherence monitoring in conjunction with
prescription monitoring programs and other screening tools, however, UDT is
associated with multiple limitations secondary to potential pitfalls related to drug
metabolism, reliability of the tests, and the knowledge of the pain physician.
UDT is a widely available and familiar method for monitoring opioid use in chronic
pain patients. UDT can provide tools for tracking patient compliance and expose
possible drug misuse and abuse. UDT is one of the major tools of adherence
monitoring in the assessment of the patient’s predisposition to, and patterns of,
drug misuse/abuse – a vital first step towards establishing and maintaining the safe
and effective use of opioid analgesics in the treatment of chronic pain.
This comprehensive review provides the role of UDT in monitoring chronic opioid
therapy along with reliability and accuracy, appropriate use, overuse, misuse, and
abuse.
Key words: Controlled substances, opioids, benzodiazepines, illicit drugs, abuse,
diversion, prescription monitoring programs, adherence monitoring, compliance
monitoring, urine drug testing, immunoassay, chromatography, false-positives,
false-negatives
Italian Registry on Long-Term Intrathecal
Ziconotide Treatment
Authors: Raffaeli William
Published: March 2021

Background: Ziconotide is commonly used for intrathecal (IT) therapy of chronic pain,
and has been recently indicated as a first-line IT drug. It is also extremely useful for patients
intolerant or refractory to the common IT drugs (such as morphine). The literature, excluding
registration studies, mostly includes small samples, and gives only fragmentary evidence on
the long-term risks and benefits of ziconotide.
Objective: To collect data on safety and efficacy of long-term ziconotide IT infusion in
Italian pain centers.
Study Design: Retrospective cohort study on the use of ziconotide in Italy. The study
was designed and coordinated by the Foundation ISAL (Algological Sciences Research
and Training Institute). Patients treated with ziconotide from several pain therapy and
neurosurgery units were included in the study, allowing the creation of the first Italian
Registry of Ziconotide.
Setting: Seventeen Italian public and private pain and neurosurgery centers.
Methods: Patients suffering from cancer or non-cancer intractable chronic pain who had
been treated with ziconotide IT infusion for at least one month. Efficacy was analyzed
considering changes on the visual analog scale of pain intensity from baseline observation.
Safety was assessed by monitoring the number and intensity of adverse events.
Results: Currently, 104 patients are included in the Italian Registry of Ziconotide. Ziconotide
was administered as the first IT drug choice to 55 patients. Seventy-two patients reported at
least a 30% pain intensity reduction with a mean dose of 4.36 µg/d. The sustained analgesic
effect (P < 0.001) of the ziconotide IT therapy was observed in a group of 45 patients who
remained in the study over 6 months without treatment interruptions and with relatively
stable doses. Sixty-six patients reported at least one side effect related to ziconotide.
However, adverse events have not always been decisive for treatment interruptions.
Limitations: Data were collected retrospectively from different pain centers that used
different methods for ziconotide treatment and clinical forms for its data collection; for this
reason there is an absence of standardized methodologies and a placebo-controlled group,
and some data were missing.
Conclusions: Ziconotide IT therapy is a treatment option commonly used for clinical
practice in 17 Italian pain therapy and neurosurgery units. It might give relief to patients
with refractory chronic pain, and it seems to have a safe profile. Long-term studies and
controlled trials are required.:
Key words: ziconotide; registry; drug safety; intrathecal; refractory chronic pain, opioid,
adverse events, long-term treatment
Double Needle Technique: An Alternative
Method for Performing Difficult Sacroiliac Joint
Injections
Authors: Gupta Sanjeeva
Published: March 2021

The sacroiliac joint (SIJ) is a common source of low back pain. The most appropriate
method of confirming SIJ pain is to inject local anesthesia into the joint to find out if
the pain decreases. Unfortunately, although the SIJ is a large joint, it can be difficult
to enter due to the complex nature of the joint and variations in anatomy. In my
experience a double needle technique for sacroiliac joint injection can increase the
chances of accurate injection into the SIJ in difficult cases. After obtaining appropriate
fluoroscopic images, the tip of the needle is advanced into the SIJ. Once the tip of the
needle is correctly placed, its position is checked under continuous fluoroscopy while
moving the C-arm in the right and left oblique directions (dynamic fluoroscopy). On
dynamic fluoroscopy the tip of the needle should remain within the joint line and not
appear to be on the bone. If the tip of the needle appears to be on the bone a new
joint line will need to be identified (the most translucent area through the joint) by
dynamic fluoroscopy and another needle advanced into the newly identified joint line.
Dynamic fluoroscopy is repeated again to confirm that the tip of the second needle
remains within the joint line. Once both needles are in place contrast dye is injected
through the needle that is most likely to be in the SIJ. If the contrast dye spread is not
satisfactory then it is injected through the other needle. I have used this technique in
10 patients and found it very helpful in accurately performing SIJ injection which can
at times be challenging.
Key words: double needle techique, sacroiliac joint, low back pain, contrast dye,
fluoroscopy
Improving the Safety of Transforaminal
Epidural Steroid Injections in the
Treatment of Cervical Radiculopathy
Authors: Block Jon E.
Published: March 2021

Background: Unplanned vascular trespass occurs in 20% of cervical transforaminal epidural
steroid injections (CTFESI) and rarely results in devastating neurologic complications. The Trucath
Spinal Injection System is a novel integrated catheter and needle device that is specifically
designed to minimize vascular trespass risk.
Objective: To compare the vascular trespass incidence with the Trucath Spinal Injection System
versus standard spinal needles during CTFESI treatment in patients with cervical radiculopathy.
Study Design: Prospective, multicenter, nonrandomized safety trial.
Setting: Six tertiary spinal pain management centers in the United States.
Methods: We treated 290 patients (411 levels) with recalcitrant cervical radiculopathy using
CTFESI; 129 patients (180 levels) were treated with the Trucath Spinal Injection System (Test
group) and 161 patients (231 levels) were treated with standard spinal needles (Control group).
All injections were administered via a transforaminal approach. Each site attained IRB approval
for this study before any research was performed. The primary study endpoint was vascular
trespass per treated level. Secondary endpoints included nerve pain or paresthesia, injection
accuracy, device performance measures, and procedural adverse events.
Results: Vascular trespass occurred more often (odds ratio (OR): 3.1, 95% Confidence Interval
(CI): 1.8-5.4, P < 0.001) in Controls (26.8%, 62/231 levels) versus Test patients (10.6%, 19/180
levels). Radicular pain or paresthesia from device positioning was more frequent (OR: 21.1, 95%
CI: 6.9-64.5, P < 0.001) in Controls (26.4%, 61/231) versus Test participants (1.7%, 3/179).
Inadequate epiradicular flow was observed in 3.0% (7/231) of Controls and 5.6% (10/179) of
Test participants (OR: 0.5, 95% CI: 0.2-1.4, P = 0.22). Based on subjective physician judgment
(scale: 1-10), there were no differences between the Test and Control groups, respectively, for
ease of use (mean 8.9 vs. 9.0), visualization under fluoroscopy (mean 9.2 vs. 9.0), and overall
performance (mean 9.0 vs. 8.6). No additional adverse effects were reported in either treatment
group in this clinical study.
Limitations: The study did not randomly allocate the type of injection procedure to participants
and no clinical outcomes beyond the initial treatment were collected.
Conclusions: The Trucath Spinal Injection System demonstrated a statistically significant
reduction in the rate of intravenous and intra-arterial trespass, procedural pain, and paresthesia,
and has similar accuracy and performance versus standard spinal needles for CTFESI treatment
of cervical radiculopathy.
Key words: cervical, epidural, radiculopathy, steroid, transforaminal, Trucath, vascular trespass
Peripheral Nerve Stimulation of the Thoracic
Paravertebral Plexus for Chronic Neuropathic
Pain
Authors: Hegarty Dominic
Published: March 2021

Persistent post surgical pain is reported in 70% of patients following thoracotomy and
mastectomy. This pain is often neuropathic in nature and occasionally it is refractory to
traditional medical and interventional management. Neurostimulation of peripheral nerves can
be a highly effective clinical modality for the management of neuropathic pain. The placement
of a percutaneously sited electrode in the thoracic paravertebral plexus offers a new and novel
mode of managing refractory thoracic neuropathic pain.
We present 2 cases that demonstrate the effectiveness of this intervention in the long-term
management of this clinical dilemma. The first case presented is that of a 61-year-old female,
with unilateral neuropathic pain for 6 years following mastectomy refractory to traditional
interventions. Targeted field stimulation of the thoracic paravertebral plexus resulted in
significant improvement for 12 years. The second case is that of a 65-year-old male, with Type II
diabetes with neuropathic thoracic pain for 6 years following multiple rib fractures (T4-T7) who
responded positively to neurostimulation of the thoracic paravertebral plexus.
Both of these cases demonstrate a relative reduction in pain intensity (> 80%), the elimination of
oral analgesics, and improved functionality directly related to the novel use of this intervention.
Effective and reproducible pain relief is achieved by specifically using a low frequency (10 Hz)
and low amplitude (2 mA) stimulation technique. Equally important is that these cases highlight
the increased risk of inadvertent pleural puncture with the development of a pneumothorax
that can be associated with this intervention. Possible clinical, investigative and equipment
modifications that need to be considered are discussed.
The limitations include only 2 case reports, considered as the lowest level of evidence available
in the era of evidence-based medicine, and lack of utilization of multiple other modalities of
treatments utilized in managing neuropathic pain.
In conclusion, these cases demonstrate the effectiveness of peripheral nerve stimulation of the
thoracic paravertebral plexus in the long-term management of refractory neuropathic pain. They
also serve to underline the importance of clinical awareness in order to improve patient safety.
Key words: Peripheral nerve stimulation, thoracic paravertebral plexus, persistent post surgical
pain, neuropathic pain, pneumothorax
The Use of Lumbar Sympathetic Blockade at
L4 for Management of Malignancy-Related
Bladder Spasms
Authors: Gulati Amitabh
Published: March 2021

Background: Cancer-related bladder spasms may be a rare but severe symptom of
bladder or metastatic cancer or its related treatments. Various treatments described
in the literature include systemic medications, intravesical or epidural medications, or
even sacral neurolectomies.
Objective: We present 3 patients who have suffered from bladder spasm
either from invasion of the bladder wall by tumor (2 patients) or from intravesical
chemotherapeutic treatment.
Design: Case Report.
Setting: Cancer pain management hospital.
Methods: For each patient, we describe the use of lumbar sympathetic block to
successfully treat the bladder spasms. Sympathetic blockade was performed at the
left anterolateral border of lumbar vertebra L4. We used 10 mL of local anesthetic
(0.25% bupivacaine) delivered in 2 mL aliquots, each given after negative aspiration
for heme. Each procedure was performed with fluoroscopic guidance (both AP and
lateral views) with the use of iodine contrast (Omnipaque-180) to confirm the location
of the medication and its resulting spread.
Results: All 3 patients had a reduction in the frequency and intensity of spasms,
with 2 out of 3 patients not having a recurrence of the spasms for up to 2 months
post procedure and follow up.
Limitations: Case Report.
Conclusion: Lumbar sympathetic blockade could be a useful treatment for recurrent
bladder spasm in the oncologic population. Based on these findings, we feel that the
branches of the sympathetic nerve set at L4 may be a good target for neurolytic
procedures, such as radiofrequency ablation, for long term treatment of bladder
spasms. Further research is necessary to determine the efficacy of this technique for
the treatment of bladder spasms in the oncologic population.
Key words: Bladder spasm, cancer pain, splanchnic nerve, lumbar sympathetic
block
Intramuscular Botulinum Toxin A (BtxA) in
Complex Regional Pain Syndrome
Authors: Schwartzman Robert
Published: March 2021

Background: Pain associated with complex regional pain syndrome (CRPS) is frequently
excruciating and intractable. The use of botulinum toxin for relief of CRPS-associated pain
has not been well described.
Objectives: To assess whether intramuscular botulinum toxin injections cause relief of
pain caused by CRPS, and to assess the risks of this treatment.
Study Design: Retrospective chart review.
Setting: Outpatient clinic.
Methods: Patients: 37 patients with spasm/dystonia in the neck and/or upper limb girdle
muscles. Intervention: Electromyography-guided injection of botulinum toxin A (BtxA),
10-20 U per muscle. Total dose used was 100 U in each patient. Measurement: Local pain
score on an 11 point Likert scale, 4 weeks after BtxA injections.
Results: Mean pain score decreased by 43% (8.2 ± 0.8 to 4.5 ± 1.1, P < 0.001). Ninetyseven percent of the patients had significant pain relief. One patient had transient neck
drop after the injections.
Limitations: This is a retrospective study; it lacks a control group and therefore the
placebo effect cannot be eliminated. This study does not provide information on the
efficacy of this treatment after 4 weeks.
Conclusion(s): Intramuscular injection of botulinum toxin A in the upper limb girdle
muscles was beneficial for short term relief of pain caused by CRPS in this retrospective case
series. The incidence of complications was low (2.7%)
Key words: Complex regional pain syndrome, botulinum toxin, spasm, dystonia
Lumbar Retrodiscal Versus Post-Ganglionic
Transforaminal Epidural Steroid Injection for
the Treatment of Lumbar Intervertebral Disc
Herniations
Authors: Park Hahck Soo
Published: March 2021

Background: Lumbar transforaminal epidural steroid injections (TFESIs) are procedures often
utilized in the treatment of radicular pain. TFESIs with a preganglionic approach have been
reported to be more effective than TFESIs performed using a classic approach. However, it is
unknown whether TFESIs using a retrodiscal approach are as effective as other approaches.
Objective: To investigate the effect of an epidural steroid injection (ESI) on radicular pain,
we conducted a randomized, controlled trial comparing a retrodiscal approach with a classic
approach to treat lumbar disc herniation.
Design: A case control study.
Methods: Forty patients were randomized to receive lumbar TFESIs with either a retrodiscal
approach (n=20) or with a classic approach (n=20). Measurements were taken before as well
as 4 and 8 weeks after treatment using a visual analog scale (VAS) score, Patient Satisfaction
Index (PSI) and the Roland 5-point pain score.
Results: In the retrodiscal group, there was a statistically significant improvement in the
VAS score after injection compared to baseline. In the classic group, there was a statistically
significant improvement in the VAS score after injection compared to baseline. There was
no statistically significant difference in the VAS score, PSI, or the Roland 5-point pain score
between those treated with a retrodiscal approache and those treated with a classic approach.
Limitations: Secondary outcomes were not measured and the study did not include a midor long-term follow-up period.
Conclusion: In this study, TFESIs performed using a retrodiscal or classic approach had
similar effects on radicular pain. The classic and the retrodiscal transforaminal steroid injection
resulted in equivalent pain relief. .
Key words: Corticosteroids, lumbar disc herniation, radicular pain, retrodiscal, transforaminal
epidural injection
Sonoanatomy and Injection Technique of the
Iliolumbar Ligament
Authors: Harmon Dominic
Published: March 2021

Background: The iliolumbar ligament plays an important biomechanic role in anchoring
the spine to the pelvic ring and stabilizing the sacroiliac joint. Iliolumbar syndrome is a
back pain condition caused by pathology of the iliolumbar ligament. History and physical
examination are important in the assessment of back pain, but they lack sufficient
specificity. Injection of small volumes of local anesthetic into the structure considered
to be the source of the pain (i.e. the iliolumbar ligament) increases the specificity of the
diagnostic workup.
Objective: To describe an ultrasound - guided technique for injecting the iliolumbar
ligament.
Study design: Case report based on knowledge of topographic anatomy and
sonoanatomy.
Setting: Outpatient clinic.
Methods: A patient with a clinical picture suggestive of iliolumbar syndrome was
selected. An ultrasound-guided injection of the iliolumbar ligament with local anesthetic
was performed. We recorded the patient’s subjective assessment of pain and the change
in range of movement and pain scores during provocative tests.
Results: Following the injection, the patient’s pain score decreased, provocation tests
became negative, and the range of movement increased.
Limitations: Case report. Target specificity and dispersion of local anesthetic spread not
confirmed with an independent technique (i.e. magnetic resonance imaging).
Conclusions: Ultrasound guidance allows the selective deposition of small volumes of
local anesthetic into structures believed to cause soft tissue back pain and thus to confirm
or exclude the working diagnosis. Further studies are needed to confirm our conclusions
and to prove the clinical feasibility of this technique.
Key words: Technique, visualization, real-time, ultrasound, iliolumbar ligament,iliolumbar
syndrome, diagnostic injection, low back pain, groin pain.
Ultrasound-Guided Interventional Release of
Rotator Interval and Posteroinferior Capsule
for Adhesive Capsulitis of the Shoulder Using a
Specially Designed Needle
Authors: Jhun Hyung-Joon
Published: March 2021

Background: Adhesive capsulitis is a common but poorly understood disorder of
the shoulder. Various treatments have been developed to manage this condition, but
the efficacy of these treatments is controversial. We developed an ultrasound-guided,
minimally invasive interventional technique to manage adhesive capsulitis of the shoulder
using a specially designed needle.
Objective: To describe the methodological approach of our intervention.
Study Design: Technical report.
Setting: Pain management clinic.
Methods: Thirteen participants with adhesive capsulitis of the shoulder underwent
ultrasound-guided interventional release of the rotator interval and posteroinferior capsule
using a specially designed curved Round Needle. A convex ultrasound probe was placed
along the oblique coronal plane over the supraspinatus muscle and acromion. Under
ultrasonographic guidance, the needle was passed through the supraspinatus muscle and
superior labrum and reached the rotator interval. It was moved forward and backward
until no resistance was felt. After finishing the rotator interval release, the needle was
inserted toward the posteroinferior capsule. While the operator released the adhesion
in the posteroinferior capsule by moving the needle forward and backward, an assistant
gradually abducted the shoulder. When full abduction of the affected shoulder was
achieved, the intervention was completed.
Results: Following our intervention, significant improvements in pain levels, glenohumeral
range of motion, and Quick Disability of the Arm, Shoulder, and Hand scores were attained
at follow-up.
Limitations: Technical report only. Efficacy of this technique is beyond the scope of the
article.
Conclusion: Ultrasound-guided interventional release of the rotator interval and
posteroinferior capsule appears to have clinical significance in the management of adhesive
capsulitis of the shoulder.
Key words: adhesive capsulitis, shoulder, ultrasound, intervention, dry needling,
technique
Neurotoxicity of Subarachnoid
Preservative-Free S (+)-Ketamine in Dogs
Authors: Garcia João Batista Santos
Published: March 2021

Background: Subarachnoid S(+)-ketamine is a matter of much debate as the results
regarding its toxicity are contradictory.
Objectives: Our objective was to investigate possible histopathological alterations after
subarachnoid administration of different doses of preservative-free S(+)-ketamine to dogs.
Study design: A randomized, blind, prospective experimental study.
Setting: Center for Research on Pain at the Federal University of Maranhão, Brazil.
Methods: Sixteen adult mongrel dogs of both sexes, each weighing 11 to 20 kg were
divided into 3 groups: Group I (n=6), 0.7 mg/kg-1 S(+)-ketamine; Group II (n=6), 0.5 mg/
kg-1 S(+)-ketamine, and a control group, Group III, (n=4), 0.9% NaCl. All substances were
administered in one mL volume doses. The animals were kept in captivity for 2 weeks; after
this period, they were put down and lumbar and sacral portions of the spinal cords were
removed for histological examination using conventional light microscopy.
Results: There were histological alterations in the spinal cords of the test subjects in
the control group. Comparison showed significant histological abnormalities in Groups
I and II when compared to the control group, including gliosis, axonal edema, central
chromatolysis, lymphocyte infiltration and fibrous thickening of the dura mater.
Limitations: Test subjects received only a single dose each. The observation period was
not very long, less than a month.
Conclusions: Subarachnoid administration of S(+)-ketamine without preservative caused
histological lesions on the spinal cord and meninges in the dogs studied. S(+)-ketamine
should not be given to clinical patients in this way until further evaluation of the significance
of this toxicity has been conducted.
Key words: S(+)-ketamine. subarachnoid, neurotoxicity, dog, histopathology