Chapter 8. Pain Management Techniques

Question 1

626. Which of the following is the most common
microbe that grows in cultures of infected
intrathecal pump wounds?
(A) Pseudomonas species
(B) Escherichia coli
(C) Staphylococcus aureus
(D) Staphylococcus epidermidis
(E) None of the above

Answer 1

626. (D)
     A. Pseudomonas species grew in 3% of infected
     wound cultures.
     B. Escherichia coli is probably among the
     unknown or not reported 20% or the multiple
     or other species (7%).
     C. and D. Staphylococcus species grew in cultures
     of infected sites 59% of the time. Most
     reports did not specify whether the cultured
     Staphylococcus organisms were S aureus
     or S epidermidis. However one study specifically
     emphasized S epidermidis, which
     arises from the skin of the patient or operating
     room personnel, as the most likely
     culprit. No growth took place in 9% of the
     infected-wound cultures. No positive fungal
     cultures were reported.

Question 2

627. You think a patient has developed an intrathecal
catheter-tip inflammatory mass. What signs
and symptoms would support this finding?
(A) Diminishing analgesic effects
(B) Pain that mimics nerve root
compression
(C) Pain that mimics cholecystitis
(D) A and B
(E) A, B, and C

Answer 2

627. (E)
     A. Subtle prodromal signs and symptoms
     during early growth of a catheter-tip mass
     include decreasing analgesic effects (loss
     of previously satisfactory pain relief) and
     unusual increase in the patient’s underlying
     pain. Another occurrence was that
     patient required unusually frequent or
     high dose escalations to obtain analgesia.
     In certain instances, dose increases and
     large drug boluses reduced the patient’s
     pain only temporarily or to a lesser degree
     than previous experiences predicted.
     B. Catheter-tip masses in the lumbar region
     sometimes simulated nerve root compression
     from a herniated intervertebral disc
     or spinal stenosis.
     C. When the catheter tip is located in the thoracic
     region, early signs and symptoms of
     an extra-axial inflammatory mass sometimes
     included thoracic radicular pain that
     stimulated intercostal neuralgia or cholecystitis.
     Gradual, insidious neurologic deterioration
     weeks or months after the appearance
     of subjective symptoms was the most
     common clinical course before the onset of
     myelopathy or cauda equina syndrome.
     Myelopathy is a term that means that
     there is something wrong with the spinal
     cord itself. This is usually a later stage of
     cervical spine disease, and is often first
     detected as difficulty while walking
     because of generalized weakness or problems
     with balance and coordination. This
     type of process occurs most commonly in
     the elderly, who can have many reasons for
     troubled walking or problems with gait
     and balance. However, one of the more
     worrisome reasons that these symptoms
     are occurring is that bone spurs and other
     degenerative changes in the cervical spine
     are squeezing the spinal cord. Myelopathy
     affects the entire spinal cord, and is very
     different from isolated points of pressure
     on the individual nerve roots. Myelopathy
     is most commonly caused by spinal stenosis,
     which is a progressive narrowing of the
     spinal canal. In the later stages of spinal
     degeneration, bone spurs, and arthritic
     changes make the space available for the
     spinal cord within the spinal canal much
     smaller. The bone spurs may begin to press
     on the spinal cord and the nerve roots, and
     that pressure starts to interfere with how the nerves function normally. Myelopathy
     can be difficult to detect, because this disease
     usually develops gradually and also
     occurs at a time in life when people are
     beginning to slow down a little bit anyway.
     Many people who have myelopathy will
     begin to have difficulty with activities that
     require a fair amount of coordination, like
     walking up and down the stairs or fastening
     the buttons on clothing. If a patient has
     had a long history of neck pain, changes in
     coordination, recent weakness, and difficulty
     doing tasks that used to be easier
     because your body seemed more responsive
     in the past, are definite warning signs
     that they should see a doctor. Surgery is
     usually offered as an early option for people
     with myelopathy who have evidence of
     muscle weakness that is being caused by
     nerve root or spinal cord compression. This
     is because muscle weakness is a definite
     sign that the spinal cord and nerves are
     being injured (more seriously than when
     pain is the only symptom) and relieving
     the pressure on the nerves is more of an
     urgent priority. However, the benefits of
     nerve and spinal cord decompression have
     to be weighed against the risks of surgery.
     Many people who have myelopathy
     caused by degenerative cervical disorders
     are older and often a bit frail. Spine surgery
     can be a difficult stress for someone who is
     old or who has many different medical
     problems. However, a surgeon will be able
     to discuss the risks and benefits of surgery,
     and what the likely results are of operative
     versus nonoperative treatment.
     Cauda equina syndrome is a serious
     neurologic condition in which there is
     acute loss of function of the neurologic
     elements (nerve roots) of the spinal canal
     below the termination (conus) of the
     spinal cord. After the conus the canal contains
     a mass of nerves (the cauda equina—
     horse tail—branches off the lower end of
     the spinal cord and contains the nerve
     roots from L1-5 and S1-5. The nerve roots
     from L4-S4 join in the sacral plexus which
     affects the sciatic nerve which travels caudally
     (toward the feet). Any lesion which
     compresses or disturbs the function of the
     cauda equina may disable the nerves
     although the most common is a central
     disc prolapse. Other causes include protrusion
     of the vertebra into the canal if
     weakened by infection or tumor and an
     epidural abscess or hematoma. Signs
     include weakness of the muscles innervated
     by the compressed roots (often
     paraplegia), sphincter weaknesses causing
     urinary retention and postvoid residual
     incontinence. Also, there may be
     decreased rectal tone; sexual dysfunction;
     saddle anesthesia; bilateral leg pain and
     weakness; and absence of bilateral ankle
     reflexes. Pain may, however, be completely
     absent; the patient may complain
     only of lack of bladder control and of saddle-
     anesthesia, and may walk into the
     consulting-room. Diagnosis is usually
     confirmed by an MRI scan or a CT scan,
     depending on availability. If cauda equina
     syndrome exists, early surgery is an
     option depending on the etiology discovered
     and the patient’s candidacy for major
     spine surgery.
     Awareness of these two phenomena and
     maintenance of an index of suspicion are
     important factors to help physicians detect
     such inflammatory masses early in the clinical
     course.
     An inflammatory mass or granuloma is
     resulted from a buildup of inflammatory
     material at the tip of the catheter. Signs and
     symptoms that warrant prompt diagnosis
     to rule out the presence of a catheter-tip
     mass include changes in the patient’s neurologic
     condition, including motor weakness,
     such as gait difficulties; sensory loss,
     including proprioceptive loss; hyper- or
     hypoactive lower extremity reflexes; and
     any evidence of bowel or bladder sphincter
     dysfunction. The practitioner should also
     be suspicious of new or different reports of
     numbness, tingling, burning, hyperesthesia,
     hyperalgesia, or the occurrence of pain
     (especially radicular pain that corresponds
     to the level of the catheter tip) during
     catheter access port injections or programmed
     pump boluses. The latter finding should alert the physician to discontinue
     the procedure and perform a diagnostic
     imaging study as soon as possible.
     If signs and symptoms suggestive of a
     catheter-tip mass are detected, the practitioner
     should first review the patient’s
     current issues, history, and neurologic
     examination. Then, a nonsurgical pain practitioner
     should review imaging studies with
     a neurosurgeon. Third, the physician should
     arrange the performance of a definitive
     diagnostic imaging procedure to confirm or
     rule out the suspected diagnosis. Treatment
     should be started in a timely fashion.
     Laboratory tests and electromyography or
     nerve conduction studies are not apparently
     useful in this situation.

Question 3

628. Advantages of intrathecal drug-delivery are
(A) the first-pass effect can be avoided
(B) intrathecal morphine is 300 times as
effective as oral morphine for equipotent
pain treatment
(C) the number of central nervous system
(CNS) derived side effects can be
reduced
(D) B and C
(E) A, B, and C

Answer 3

628. (E)
     A. The premise behind intrathecal drug
     delivery is that by directly depositing
     drugs into the CSF, the first-pass effect is
     avoided.
     B. Intrathecal morphine is 300 times as effective
     as oral morphine for equipotent pain
     treatment. From spinal to epidural morphine
     the conversion is in the ratio of 1:10.
     From epidural to IV morphine the conversion
     is in the ratio of 1:10. From IV to oral
     morphine the conversion is in the ratio of
     1:3, hence 10 × 10 × 3 = 300.
     C. By the direct action of the medication, the
     number of CNS-derived side effects can be
     reduced.

Question 4

629. Which one of the following is not an item to contemplate
prior to placing an intrathecal pump?
(A) Does the patient have an acceptable
physiologic explanation for the pain
syndrome
(B) Does the patient have a life expectancy
of 3 months or longer
(C) Psychologic clearance is not needed in
the patient with cancer pain
(D) How old is the patient
(E) Has the patient been reasonably
compliant with past treatment
recommendations

Answer 4

629. (D) In choosing the right patient for an intrathecal
     drug-delivery system, several important
     questions must be asked, like
     A. Does the patient have an adequate physiologic
     explanation for the pain syndrome?
     Does the diagnosis require aggressive pain
     treatment?
     B. Does the patient have a life expectancy of
     3 months or longer (required for both cancer
     and noncancer patients)?
     C. Is the patient psychologically stable? A
     psychologist should assess the patient’s
     mental status and stability prior to the
     procedure. Outcomes have been shown to
     deteriorate with the presence of untreated
     depression, untreated anxiety disorders,
     and suicidal or homicidal ideation. Results
     have also been negatively influenced by
     the presence of untreated illicit substance
     dependence. The presence of a personality
     disorder such as borderline, antisocial, or
     multiple personality disorder should
     cause extreme caution, with these patient
     receiving implants only in extenuating circumstances.
     Psychologic clearance is not
     needed in the patient with cancer pain, but
     many of these patients may benefit from
     counseling to better cope with the disease
     process.
     E. Has the patient been reasonably compliant
     with past treatments? Has the patient failed
     other, less invasive therapies? What were
     they? Were they documented? Do they
     include physical therapy and oral medications?
     Are more conservative therapies unacceptable,
     not desired, or contraindicated? Do
     the symptoms of pain affect the patient’s
     ability to function? Does the patient have a
     contraindication, such as a bleeding diathesis,
     or a localized or systemic infection? Has
     the patient had a successful intrathecal medication
     trial? The physician should write a
     detailed note regarding symptom relief, side
     effects, and overall patient acceptance. Does
     the patient have a realistic view of expectations?
     Does the patient accept the risks of the
     procedure/device and future medications?

Question 5

630. Prior to implanting an intrathecal pump many
     practitioners perform an intrathecal medication
     trial. Significant parameters to consider
     include
     (A) delivery site
     (B) type of medication
     (C) whether the patient should be admitted
     (D) A and B
     (E) A, B, and C

Answer 5

630. (D)
     A. and B. There is a definite justification for a
     trial that mimics the conditions that will be
     achieved by the implanted system. Important
     parameters include
     • Site of medication delivery (intrathecal
     versus epidural, and spinal level)
     • Whether the medication is delivered as a
     bolus or an infusion
     • Infusion rate
     • Dose/concentration range
     • Length of trial
     • Medication selected for trial
     C. The patient should always be admitted
     and observed after an intrathecal medication
     trial. There was a comparison of trial
     methods in pain patients (nociceptive,
     neuropathic, or mixed) selected to have
     intrathecal pump placement. In the final
     analysis at 12 months after implantation, it
     was determined that there was no significant
     difference in trial method (single-shot
     intrathecal, continuous intrathecal, or continuous
     epidural) in outcomes with nociceptive
     pain. However, in neuropathic
     pain syndromes, the initial success of trial
     was significantly better if a continuous
     method was used. There was no difference
     noted in trial through the epidural route
     versus trial through the intrathecal route.
     The main difference between successful
     trials in patients with neuropathic pain
     and mixed pain syndromes was the inclusion
     of more than one medication to
     improve the success of the trial.
     Morphine has been approved by the
     FDA for intrathecal drug-delivery systems,
     and is often the first choice of drug
     for trial. Local anesthetics or α-receptor–
     acting drugs are sometimes added to the
     trial in patients with burning or lancinating
     extremity pain with hopes of improving
     the success of the trial.
     To be considered a success, the trial
     should induce significant pain relief, with
     minimal side effects, and noncancer patients
     should obtain purposeful improvement of
     function.

Question 6

631. When dealing with an infection, which of the
     following would favor explanting the intrathecal
     device?
     (A) Associated bleeding
     (B) The presence of a seroma
     (C) The presence of a hygroma
     (D) The presence of necrotic tissue around
     the wound
     (E) All of the above

Answer 6

631. (D)
     A. Bleeding at the wound site will be obvious
     with seepage into the dressing. Associated
     signs include edema, discoloration, and
     rubor. It can usually be treated with ice and
     compression; however, surgical exploration
     may be necessary. The presence of an active
     bleed does not necessitate the explantation
     of the intrathecal drug-delivery system.
     B. A seroma is a collection of noninfectious
     fluid. It is usually treated with pressure
     dressings and conservatively allowing for
     resorption. If conservative treatment is not
     efficacious, sterile aspiration may be necessary.
     Its presence does not require the
     removal of the intrathecal pump.
     C. A hygroma is a collection of CSF. Its most
     common cause is leakage of fluid around
     the catheter entry point and into the
     pocket. It can be treated with abdominal
     pressure, caffeine, and increased fluid
     intake.
     D. Infection of the wound may be minor and
     superficial, or it may be severe enough to
     warrant the removal of the pump. An
     infection may present with fever, redness,
     frank pus, or purulent wound drainage.
     Incision and drainage, qualification of
     pathogenic culprit, and antibiotic therapy
     must be undertaken immediately. The
     decision to excise the pump is made based
     on the presence of necrotic tissue, the overall
     condition of the wound, and the condition
     of the patient.
     The two most disastrous complications
     are epidural hematoma and neuraxial
     infection. An epidural hematoma may
     result in paralysis and should be suspected
     with any change in neurologic status
     postoperatively. This is an emergency
     and an immediate MRI and neurosurgical
     consultation should be obtained. The presence
     of an intrathecal pump is not a contraindication
     to MRI, and should not delay
     its use. A neuraxial infection can include
     meningitis or an epidural abscess and they
     must both be diagnosed immediately so
     that treatment can be started expeditiously.

Question 7

632. You have separately tried maximum doses of
     morphine and hydromorphone, in a patient’s
     intrathecal pump without any efficacy. According
     to the 2007 Polyanalgesic Consensus Guidelines,
     which one of the following would not be an
     accepted “next” step?
     (A) Switch to morphine plus bupivacaine
     (B) Switch to ziconotide
     (C) Switch to clonidine
     (D) Switch to fentanyl
     (E) Switch to hydromorphone plus
     ziconotide

Answer 7

632. (C) For the 2007 Polyanalgesic Consensus
     Guidelines, baclofen and midazolam were
     moved to special consideration categories.
     Midazolam may be used in end of life situations
     but only minimal/anecdotal evidence
     exists. Baclofen is to be used in patients that
     have spasticity-related pain, diseases associated
     with dystonia, or unrelenting spasms in
     muscle. It works via blockade of GABAB receptors
     in the spinal cord. Indications for intrathecal
     baclofen therapy: patient is intolerant of
     oral agents, pain is inadequately treated with
     oral agents, need exact control of dosing that only intrathecal delivery allows. Efficacy in
     neuropathic pain has been noted through case
     reports at doses of 100 to 460 μg/d (maximum
     FDA dosing is 900 μg/d). If significant dose
     increases are taking place, consider mechanical
     problems. Very good for exceptional long-term
     tolerability is expected. However, baclofen is
     not without complications. Withdrawal can
     occur secondary to catheter disruption, battery
     failure, or human error. There is a very wide
     spectrum of presentation ranging from asymptomatic
     to death. Granulomas are very rare.
     Overdose is usually results from human error
     and can be reversed with physostigmine, and
     flumazenil.

Question 8

633. Ziconotide was approved for infusion into the
     cerebrospinal fluid (CSF) using an intrathecal
     drug-delivery system by the Food and Drug
     Administration (FDA) in 2004. Its proposed
     mechanism of action is
     (A) it blocks sodium channels
     (B) it blocks α2δ voltage-gated calcium
     channels
     (C) it blocks N-type calcium channels
     (D) it blocks γ-aminobutyric acid (GABAB)
     receptors in the spinal cord
     (E) none of the above

Answer 8

633. (C)
     A. Numerous medications work by blocking
     sodium channels. Ziconotide is not one of
     them.
     B. Pregabalin and gabapentin work by acting
     on α2δ voltage-gated calcium channels. Their
     exact mechanism of action is unknown, but
     their therapeutic action on neuropathic pain
     is thought to involve voltage-gated N-type
     calcium ion channels. They are thought to
     bind to the α2δ subunit of the voltagedependent
     calcium channel in the CNS.
     C. Ziconotide is a nonopioid, non-NSAID
     (nonsteroidal anti-inflammatory drug),
     nonlocal anesthetic used for the amelioration
     of chronic pain. Derived from the cone
     snail Conus magus, it is the synthetic form
     of the cone snail peptide ω-conotoxin MVII-
     A. Previously known as SNX-111, it is a
     neuronal-specific calcium-channel blocker
     that acts by blocking N-type, voltage-sensitive
     calcium channels.
     Scientists have been intrigued by the
     effects of the thousands of chemicals in
     marine snail toxins since the initial investigations
     in the late 1960s by Baldomero
     Olivera, who remembered the deadly
     effects from his childhood in the
     Philippines. Ziconotide was discovered in
     the early 1980s by Michael McIntosh, at
     the time barely out of high school and
     working with Olivera. It was developed
     into an artificially manufactured drug by
     Elan Corporation. It was approved for
     sale under the name Prialt by the FDA in
     the United States on December 28, 2004,
     and by the European Commission on
     February 22, 2005.
     The mechanism of ziconotide has not
     yet been discovered in humans. Results in
     animal studies suggest that ziconotide
     blocks the N-type calcium channels on the
     primary nociceptive nerves in the spinal
     cord.
     As a result of the profound side effects
     or lack of efficacy when delivered through
     more common routes, such as orally or
     intravenously, ziconotide must be administered
     intrathecally (directly into the
     spine). As this is by far the most expensive
     and invasive method of drug delivery and
     involves additional risks of its own,
     ziconotide therapy is generally considered
     appropriate (as evidenced by the range of
     use approved by the FDA in United States)
     only for management of severe chronic
     pain in patients for whom intrathecal (IT)
     therapy is warranted and who are intolerant
     of or refractory to other treatment,
     such as systemic analgesics, adjunctive
     therapies or IT morphine.
     The most common side effects are dizziness,
     nausea, confusion, and headache.
     Others may include weakness, hypertonia,
     ataxia, abnormal vision, anorexia, somnolence,
     unsteadiness on feet, and memory
     problems. The most severe, but rare side
     effects are hallucinations, suicidal ideation,
     new or worsening depression, seizures, and
     meningitis. Therefore, it is contraindicated
     in people with a history of psychosis, schizophrenia,
     clinical depression, and bipolar
     disorder.
     D. Baclofen’s proposed mechanism of action
     is by blocking the GABAB receptors in the
     spinal cord.

Question 9

634. Neurology consults you on a 65-year-old female
     with breast cancer that has diffusely metastasized
     to her bones. She has had an intrathecal
     pump for 4 months, and has just been diagnosed
     with meningitis. Which of the following
     is true?
     (A) The pump must be removed
     (B) Enteral antibiotics must be initiated
     immediately
     (C) If the infection is sensitive to vancomycin,
     and the patient refuses pump
     removal, intrathecal vancomycin may be
     administered
     (D) Intravenous (IV) vancomycin plus
     epidural vancomycin has not been
     found to be effective in resolving infection
     (E) All of the above

Answer 9

634. (C)
     A. The diagnosis of aseptic or viral meningitis
     in the cancer patient with an intrathecal
     pump should not be an automatic reason
     for explantation of the device. Supportive care and neurologic monitoring should be
     provided until the symptoms resolve, but
     the pump and catheter do not need to be
     removed. If the meningitis is of a bacterial
     etiology, risk assessment, pain stratification,
     and life expectancy should be considered.
     Removal of the pump is suggested,
     but is not required because there is a
     potential for severe, uncontrolled pain.
     B. Parenteral (IV) not enteral (via the GI tract)
     antibiotics should be started immediately
     if bacterial meningitis is suspected. More
     specific antibiotics should be administered
     after cerebrospinal bacterial cultures and
     sensitivities are obtained.
     C. If the infection is vancomycin sensitive,
     and the patient refuses pump explantation,
     intrathecal vancomycin may be administered
     at 10 mg/d. Intrathecal vancomycin
     has been used successfully for 6 months in
     such patients.
     D. The same group found that IV vancomycin
     combined with epidural vancomycin
     (150 mg/d for 3 weeks) abolished infection.

Question 10

635. A 72-year-old male with end-stage metastatic
     prostate cancer has a life expectancy of 6 months.
     Which of the following is true with regards to
     managing his intrathecal drug-delivery system?
     (A) Treatment decisions should be made
     based on the 2007 Polyanalgesic
     Consensus Guidelines for management
     of chronic, severe pain
     (B) Fentanyl is considered a first-line
     medication
     (C) Droperidol may be used, intrathecally,
     as a first-line medication for nausea
     (D) A different algorithm is applied when a
     patient’s life expectancy is less than
     18 months
     (E) None of the above

Answer 10

635. (C)
B. and C. Morphine or hydromorphone should
be used for nociceptive pain. Bupivacaine
should be used for neuropathic pain.
Morphine or hydromorphone plus bupivacaine
should be used for mixed pain.
Droperidol is 95% efficacious in the treatment
of nausea and vomiting secondary to opioid
intolerance, abdominal tumors, and/or
chemotherapy/radiation therapy, and can be
added at this point (dose: 25-250 μg/d).
Morphine, hydromorphone, or fentanyl/
sufentanil with bupivacaine and
clonidine for nociceptive or mixed pain.
Morphine, hydromorphone, or fentanyl/
sufentanil with bupivacaine for neuropathic
pain.
Morphine, hydromorphone, or fentanyl/
sufentanil with more than two adjuvants:
the physician should use opiate
plus local anesthetic plus clonidine and
• Baclofen for spasticity, myoclonus, or
neuropathic pain
• Bupivacaine for neuropathic pain
• Second opioid (lipophilic/hydrophilic)
as an adjuvant
Morphine, hydromorphone, or fentanyl/
sufentanil with more than three
adjuvants: in addition to second-line adjuvants,
the physician should add
• Ketamine for neuropathic pain secondary
to cord compression
• Midazolam for neuropathic pain
• Droperidol for neuropathic pain
Tetracaine may be used for chemical
paralysis for inoperable cord compression,
tachyphylaxis, or emergency hyperalgesia
rescue.
Some cases may necessitate six adjuvants
to control pain at the end of life with
minimal side effects.

Question 11

636. Granulomas have been found to occur with all
medications used intrathecally, EXCEPT
(A) clonidine
(B) sufentanil
(C) baclofen
(D) fentanyl
(E) B and D

Answer 11

636. (B) The 2007 Polyanalgesic Consensus
     Guideline panelists have addressed this topic
     fully. All panelists felt that catheter-related
     granulomas still remains one of the most grave
     adverse effects and risks of intrathecal pain
     management and impediments to the widespread
     use of the therapy. Several factors contribute
     to the development of granuloma,
     including the agent used, catheter position
     (majority of granulomas occur in thoracic
     area—where CSF volume and flow are
     reduced), CSF volume (especially if low), and
     the dose and concentration of the drug (low
     CSF volume means higher concentrations of
     drug). With morphine, the preponderance of
     cases have been described in patients receiving
     concentrations of 40 mg/mL or greater. In cases
     where hydromorphone was implicated, the
     majority of cases received concentrations of
     10 mg/mL or greater. Even though some panelists
     felt that positioning the catheter into the
     larger CSF volume of the dorsal intrathecal
     space of the low thoracic cord, granulomas do
     occur even in cases where catheters have been
     inserted into that space. However, concentration
     of the agent used appears to be the major
     causal factor of intrathecal, catheter-related
     granulomas. A., B., C., and D. Inflammatory masses
     have been reported to be associated with all
     medications administered in the intraspinal
     space except for sufentanil and rarely for fentanyl.
     As of this writing, there have been at
     least three reports published in the literature
     of baclofen-related granulomas. Even though
     the literature suggests a granuloma protective
     effect of clonidine, there have been reports of
     patients with intrathecal clonidine, alone, or
     in combination with other intrathecal agents
     developing granulomas.

Question 12

Match the associated side effects with the intrathecal
medication that causes it. Each choice can be used
once, more than once, or not at all, and each question
can have more than one answer.
637. Urinary retention
638. Extrapyramidal side effects
639. Hypotension
640. Auditory disturbances
641. Sedation
642. Nausea
643. Worsening of depression
(A) Opioids
(B) Bupivacaine
(C) Baclofen
(D) Clonidine
(E) Droperidol
(F) Ketamine
(G) Midazolam

Answer 12

637 to 643. 637 (A and B); 638 (E); 639 (B and D);
640 (C); 641 (A, D, and G); 642 (A); 643 (D)
Opioids can cause sedation, edema, constipation,
nausea, and urinary retention.
Bupivacaine can cause urinary retention,
weakness, and hypotension.
Baclofen can cause loss of balance, and auditory
disturbances.
Clonidine can cause orthostatic hypotension,
worsening of depression, edema, and sedation.
Droperidol can cause extrapyramidal side
effects such as tremor, slurred speech, akathisia,
dystonia, anxiety, distress, and paranoia.
Ketamine can cause increased anxiety and
irritability, delusional ideation, and facial
flushing.
Midazolam can cause sedation.
If a medication is not therapeutic for a
patient or is causing significant adverse effects,
it should be properly weaned, and the patient
should be informed of likely withdrawal
symptoms and arrange for outpatient interventions.
Acute baclofen or clonidine termination
can result in hemodynamic derangements,
seizures, or death. To avoid these untoward
effects, physicians should introduce oral
replacement therapy on the stoppage of
intrathecal medications and provide an appropriate
weaning schedule to the patient.

Question 13

644. A 43-year-old female has 8-month history of
     axial low back pain and pain radiating to the
     left leg. The magnetic resonance imaging (MRI)
     of lumbosacral spine shows severe degenerative
     disc disease at L3-4 through L5-S1 with
     mild disc protrusions at these levels. She is a
     possible candidate for
     (A) transforaminal epidural steroid injection
     (B) facet joint medial branch diagnostic
     block
     (C) spinal cord stimulator (SCS) trial
     (D) all of the above
     (E) none of the above

Answer 13

644. (D)
     A. The epidural steroid injections (ESI) and
     SCS are treatment choices for radicular
     pain caused in particular by disc herniation causing mechanical and chemical irritation
     of the nerve root.
     B. Presence of axial low back pain even in
     absence of MRI changes can indicate possible
     facet arthropathy. Facet and medial
     branch diagnostic blocks are likely the
     most sensitive and specific diagnostic test
     for facet pain. Facet radiofrequency (RF)
     denervation seems to be the best treatment
     choice for patients with short-term relief
     with facet blocks.
     C. The SCS trial may be an excellent choice
     for radiating pain down the leg.

Question 14

645. The causes of axial low back pain are
(A) sacroiliac (SI) arthropathy
(B) internal disc disruption
(C) quadratus lumborum and psoas
syndrome
(D) all of the above
(E) none of the above

Answer 14

645. (D)
     A. SI joint injection with local anesthetics and
     steroids may have good diagnostic and
     possibly therapeutic value if the pain is
     located in the SI joints.
     B. Internal disc disruption or discogenic
     pain can be diagnosed with provocative
     discography.
     C. Quadratus lumborum and psoas muscle
     pain represent a form of myofascial pain
     that can be a cause of low back pain.
     Diagnostic blocks may have a value in diagnosis
     of this type of myofascial pain.

Question 15

646. The false-positive rate of diagnostic lumbar
facet medial branch blocks are
(A) 8% to 14%
(B) 15% to 22%
(C) 3% to 5%
(D) 25% to 41%
(E) 41% to 50%

Answer 15

646. (D) Diagnostic medial branch blocks have a
     very high false-positive rate as reported in
     studies. This can potentially decrease the success
     rate of RF denervation of facet joints since
     this procedure is based on good short-term
     results with diagnostic medial branch blocks.
     For this reason repeated confirmatory diagnostic
     block and use of small dose of local anesthetics
     (0.3-0.5 mL) is recommended by many.

Question 16

647. Percentage of cases where the pain relief is
caused by placebo response following interventional
procedures are
(A) 12%
(B) 35%
(C) 20%
(D) 15%
(E) 28%

Answer 16

647. (B) Placebo effect is responsible for pain relief
     in up to 35.2% interventional procedures.
     Despite the high rates of placebo response it is
     not recommended for routine clinical use.

Question 17

648. The complication of sphenopalatine ganglion
radiofrequency thermocoagulation is
(A) infection
(B) epistaxis
(C) bradycardia
(D) all of the above
(E) none of the above

Answer 17

648. (D)
     A. Infection is a rare complication that can be
     difficult to treat.
     B. It seems that the epistaxis is more common
     than thought and can occur if too much pressure is applied to the RF cannula.
     Hematoma can occur if maxillary artery of
     venous plexus is punctured.
     C. Bradycardia is likely caused by reflex similar
     to the oculocardiac reflex.

Question 18

649. The complication of third occipital nerve (TON)
radiofrequency thermocoagulation is
(A) change in taste
(B) ataxia
(C) dysphagia
(D) all of the above
(E) none of the above

Answer 18

649. (B)
     A. Change in taste would more likely be associated
     with glossopharyngeal nerve, lingual
     nerve, and chorda tympani.
     B. Ataxia can occur in up to 95% cases of RF
     denervation of the TON, numbness in 97%,
     dysesthesia in 55%, hypersensitivity in
     15%, and itching in 10% of cases. Third
     occipital neurotomy almost always partially
     denervates semispinalis capitis muscle
     and so interferes with tonic neck
     reflexes and causes ataxia in particular on
     looking downward. The sensation is readily
     overcome by relying on visual cues such
     as fixing on the horizon.
     C. Dysphagia is not associated with TON
     thermocoagulation

Question 19

650. Positive lumbar provocative discogram for
     mechanical disc sensitization includes reproduction
     of patient’s pain with injection of the
     contrast in nucleus pulposus at what pressure
     above the “opening pressure”?
     (A)

Answer 19

650. (D)
     A. Provocative discography is best done while
     pressure of contrast has been continuously
     measured. Reproduction of pain at 6/10
     and pain location and quality should be
     similar to the chronic low back pain.

Question 20

651. The technique of cervical discography includes
needle entry through the skin from the
(A) anterior right side of the neck
(B) posterior right side of the neck
(C) anterior left side of the neck
(D) posterior left side of the neck
(E) median posterior side of the neck

Answer 20

651. (A) Cervical discography is performed with
     patient in supine position, using oblique
     approach, similar to the stellate ganglion block.
     The esophagus is normally positioned slightly toward the left side of the neck. To prevent
     puncturing it, the best technique for needle
     insertion for cervical discography is anterior
     right-sided approach.

Question 21

652. When performing intralaminar cervical epidural
     steroid injections without fluoroscopic guidance,
     the chances of having false positive loss
     of resistance are close to
     (A) 15%
     (B) 25%
     (C) 35%
     (D) 50%
     (E) 40%

Answer 21

652. (D) The ligamentum flavum is discontinuous
     in cervical levels, therefore allowing for very
     high chances of false loss of resistance technique
     and therefore mandates the use of fluoroscopy
     and contrast administration. The use of
     fluoroscopy may improve the safety of this procedure,
     medication delivery to the site of
     pathology, and potential outcomes. In lumbar
     levels it seems that the false loss of resistance in
     nonfluoroscopically performed epidural
     steroid injections occurs in up to 30% of cases.

Question 22

653. When performing intralaminar cervical epidural
     steroid injections, the unilateral contrast (and
     medication) spread is expected in what percentage
     of cases?
     (A) 50%
     (B) 30%
     (C) 25%
     (D) 10%
     (E) 40%

Answer 22

653. (A)
     A. Although there is no median septum of fat
     in cervical epidural levels the unilateral
     medication spread is common. Therefore
     injections should be performed toward the
     laterality of pathology.
     B. False loss of resistance technique when not
     performed under fluoroscopy is 30% in
     lumbar levels and 50% in cervical levels.
     C. Ventral epidural spread in cervical levels is
     close to 25%.
     D. Too low.
     E. Unilateral contrast spread in intralaminar
     cervical epidural injections may occur in
     roughly 50% of all cases.

Question 23

654. Which of the following is a complication of
lumbar sympathetic block?
(A) Genitofemoral neuralgia
(B) Retrograde ejaculation
(C) Intravascular injection
(D) All of the above
(E) None of the above

Answer 23

654. (D)
     A. Genitofemoral neuralgia is very rare complication
     of lumbar sympathetic block but
     can occur since the genitofemoral nerve
     originates from L1 and L2 nerve root.
     B. In retrograde ejaculation, the bladder
     sphincter does not contract and the sperm
     goes to the bladder instead of penis. This
     can lead to infertility.
     C. Intravascular injection of large dose of
     local anesthetics can lead to seizures.

Question 24

655. What is the best method for evaluating the adequacy
of lumbar sympathetic block?
(A) Increase in temperature by 2°F
(B) Increase in temperature by 5°F
(C) Increase in temperature by 10°F
(D) Temperature change
(E) Decrease in temperature by 2°F

Answer 24

655. (D) Any temperature change in comparison to
     preprocedure temperatures is adequate enough
     to assess the adequacy of successful block.

Question 25

656. Stellate ganglion is located between the
(A) C6-C7
(B) C7-T1
(C) C5-C7
(D) C5-C6
(E) T1-T2

Answer 25

656. (B) The stellate ganglion is formed by fusion of
     inferior cervical ganglion resting over the anterior
     tubercle of C7 and first thoracic ganglion
     resting over the first rib.

Question 26

657. In relation to the stellate ganglion the subclavian
artery is located
(A) anteriorly
(B) posteriorly
(C) laterally
(D) medially
(E) none of the above

Answer 26

657. (A) In relation to stellate ganglion the subclavian
     artery is located anteriorly. For this reason,
     care should be taken not to inject

Question 27

658. Despite satisfactory stellate ganglion block for
     sympathetic-mediated pain, the pain relief in
     upper extremity is inadequate. The technical explanation for this may lie in inadequate
     spread of local anesthetics to
     (A) C5 nerve root
     (B) inferior cervical ganglion
     (C) first thoracic ganglion
     (D) T2 and T3 gray communicating rami
     (E) C7 nerve root

Answer 27

658. (D)
     A. C5 nerve root injection may provide analgesia
     by sensory block.
     B. Inferior cervical ganglion is part of the stellate
     ganglion.
     C. First thoracic ganglion is part of the stellate
     ganglion.
     D. The T2 and T3 gray rami do not pass through
     the stellate ganglion but join the brachial
     plexus and innervate the upper extremity.
     Failure to block these structures may result in
     inadequate block (Kuntz nerves).

Question 28

659. When performing lumbar discography, the
     “opening pressure” is the recorded pressure
     signifying
     (A) first appearance of the contrast in
     nucleus pulposus
     (B) opening of the annular tear to the contrast
     (C) reproduction of concordant pain
     (D) resting pressure transduced from the
     nucleus
     (E) a dural leak

Answer 28

659. (A)
A. The opening pressure is always subtracted
from pressure reproducing pain in final
calculations (eg, positive discography
means: pressure with pain reproduction—
opening pressure

Question 29

660. Intradiscal electrothermal coagulation (IDET)
outcomes are adversely affected by
(A) appearance of the disc on T2-weighted
MRI images
(B) obesity
(C) age
(D) coexisting radicular pain
(E) gender

Answer 29

660. (B)
     A. Discs are usually dark (dehydrated) on T2-
     weighted MRI images and this can only
     suggest discogenic pain.
     B. Morbid obesity can decrease the success
     rate and increase the risks of IDET.
     C. There are no studies proving that age
     influences outcomes of IDET but it seems that advanced age may decrease the rate of
     success of IDET treatment.
     D. Radicular pain directly does not predict
     the outcome of IDET. Discogenic pain
     (referred pattern) can sometimes mimic
     radicular pain.

Question 30

661. When performing lumbar discography, in relation
     to the laterality of pain, which of the following
     should be the needle entry site?
     (A) Ipsilateral
     (B) Contralateral
     (C) Laterality does not make a difference
     (D) Guided by MRI images
     (E) None of the above

Answer 30

661. (C) It does not seem that the outcomes of
     discography are affected by laterality of needle
     insertion site.

Question 31

662. Apatient with painful sacroiliac joint syndrome
     had only short-term relief with two sacroiliac
     (SI) injections using local anesthetics and
     steroids. Which of the following is the next treatment
     option?
     (A) SI joint fusion
     (B) S1, S2, S3, S4 radiofrequency
     denervation
     (C) L5, S1, S2, S3 radiofrequency
     denervation
     (D) L4, L5, S1, S2, S3 radiofrequency
     denervation
     (E) None of the above

Answer 31

662. (D) SI joint fusion has been used in the past as
     a treatment of SI pain with unfavorable results.
     The L4, L5, S1, S2, and S3 radiofrequency
     denervation is shown to be beneficial longterm
     treatment option in patients with SI pain.

Question 32

663. Which of the following includes published
complications that may follow cervical transforaminal
epidural steroid injection?
(A) Epidural abscess
(B) Neuropathic pain
(C) Quadriplegia and death
(D) All of the above
(E) None of the above

Answer 32

663. (D)
     A. Epidural abscess should be suspected if
     increased pain and new neurologic symptoms
     occur after the cervical epidural
     steroid injection.
     B. Neuropathic pain may occur following
     epidural steroid injection.
     C. If the steroid solution is injected intravascularly
     serious complications including
     possible spinal cord infarction may occur.
     The digital subtraction fluoroscopy and
     blunt needle use may help to minimize its
     occurrence if this procedure is performed.

Question 33

664. In order to minimize the risk for complications
     when cervical transforaminal epidural steroid
     injection is performed how should the needle be
     positioned in relation to the neural foramina?
     (A) Anteriorly
     (B) Posteriorly
     (C) Superiorly
     (D) Inferiorly
     (E) None of the above

Answer 33

664. (B) Placing needle posteriorly may minimize

the risk of intravascular injection.

Question 34

665. The single-needle approach to medial branch
     block diagnosis in comparison to standard
     multiple-needle approach
     (A) causes less discomfort for the patient
     (B) decreases the volume of local anesthetics
     used for the skin and subcutaneous
     tissues
     (C) takes less time to perform
     (D) all of the above
     (E) none of the above

Answer 34

665. (D)
A. The use of single-needle technique may
decrease procedural discomfort during
medial branch blocks.
B. By minimizing the amount of local anesthetics
for the skin and subcutaneous tissues
the rate of false-positive blocks caused
by treatment of myofascial pain may be
diminished.
C. This approach may take less time to perform
than the traditional multiple-needle
technique.

Question 35

666. The incidental intrathecal overdose of intrathecal
morphine while performing a pump refill
should be treated by
(A) intrathecal and IV naloxone
(B) airway protection
(C) possible irrigation of the CSF with saline
(D) all of the above
(E) none of the above

Answer 35

666. (D)
     A. If IV naloxone is inadequate, intrathecal
     naloxone may be considered.
     B. Airway protection may be needed because
     of respiratory depression.
     C. Possible irrigation of CSF with saline may
     be necessary.

Question 36

667. While analyzing a malfunctioning SCS implanted
     device, a sign of lead breakage or disconnect is a
     measured impedance of
     (A) 1500 Ω
     (C) 4000 Ω
     (E)

Answer 36

667. (D) Increased impedance may mean that there
     is lead fracture, disconnect, fluid leakage causing
     short circuit. The exactly same impedance
     at multiple leads may mean that there is a
     communication and short circuit between the
     leads.

Question 37

668. Accurate placement of a stimulator lead for
     occipital nerve peripheral stimulation is
     (A) posterior to the C3 spinous process
     (B) lateral to the pedicles of C2 and C3
     (C) 2 mm lateral to the odontoid process
     (D) posterior to the C2 spinous process
     (E) none of the above

Answer 37

668. (D) The lead should be positioned subcutaneously
     posterior to the C2 spinous process
     and perpendicular to the cervical spine.

Question 38

669. Adequate SCS introducer needle epidural
space at entry level for the desired coverage of
the foot pain is
(A) L3-4 interspace
(B) L1-L2 interspace
(C) T12-L1 interspace
(D) T8-T9 interspace
(E) T10-T11 interspace

Answer 38

669. (A) For the coverage of the foot, the SCS electrode
     position should be at the T11-T12 level.
     The more caudal entry level is desired in order
     to leave enough of the SCS lead in the epidural
     space and prevent dislodgement.

Question 39

670. The placement of SCS electrodes for coverage
of intractable chest pain caused by angina
should be at the epidural level of
(A) T6
(B) C4-C5
(C) T1-T2
(D) C6-C7
(E) C3-C4

Answer 39

670. (C) In order to position the lead at T1-T2 level
     commonly the entry site may be at lower thoracic
     levels owing to the narrow space in
     between the laminae in thoracic spine.

Question 40

671. Most effective approach for performing lumbar
epidural steroid injections is
(A) caudal
(B) interlaminar
(C) paramedian approach
(D) transforaminal
(E) Taylor approach

Answer 40

671. (D) Although there is insufficient evidence, one
     study reported that transforaminal approach
     has better outcomes in comparison to interlaminar
     approach for epidural steroid injections.
     The caudal approach requires diluted
     solution and may not reach the area of pathology
     in some cases.

Question 41

672. During interlaminar epidural steroid injections
contrast should be
(A) used in the anteroposterior view
(B) used in the lateral view
(C) used in oblique view
(D) no contrast should be used
(E) A, B, and C

Answer 41

672. (A) Contrast media should be administered in
     anteroposterior view in order to rule out
     intravascular uptake.

Question 42

673. Which of the following is the most likely complication
     after successful SCS implant?
     (A) Infection
     (B) Persistent pain at the implant site
     (C) Lead breakage or migration
     (D) CSF leak requiring surgical intervention
     (E) Paralysis or severe neurologic deficit

Answer 42

673. (C)
     A. Infection rate of implanted hardware has
     been estimated at 3% to 5%.
     B. Persistent pain at the implant site has been
     estimated at approximately 5%.
     C. Lead breakage or migration has been estimated
     at 11% to 45%.
     D. CSF leak requiring surgical intervention
     has been reported.
     E. Paralysis or severe neurologic deficit is
     possible as with any type of spine surgery,
     but is not cited as a frequent occurrence.

Question 43

674. Which of the following is the most accurate
     statement regarding efficacy of SCS?
     (A) For failed back surgery patients, SCS in
     addition to conventional medical management
     can provide better pain relief
     and improve health-related quality of
     life as compared to conventional medical
     management alone
     (B) SCS is inefficacious for the indication of
     angina pectoris
     (C) SCS for CRPS is efficacious for only
     about a year only then the efficacy
     diminishes
     (D) SCS is not an effective treatment for
     sympathetically mediated pain
     (E) Nociceptive pain is considered a better
     indication for SCS than neuropathic
     pain

Answer 43

674. (A)
     A. One study which validates this statement
     was published in the journal Pain in 2007. A
     randomized, crossover study was performed
     with intent-to-treat analysis for
     more than 12 months. One hundred
     patients were randomized to either SCS
     and conventional medical management or
     conventional medical management only.
     More patients in the SCS group achieved
     the primary outcome of 50% or more pain
     relief in the legs. Other secondary measures
     were also improved in the SCS group.
     [Kumar K, Taylor RS, Jacques L, et al. Spinal
     cord stimulation versus conventional medical
     management for neuropathic pain: a
     multicenter randomized controlled trial in
     patients with failed back surgery syndrome.
     Pain. 2007;132(1-2):179-188.]
     B. In a 2009 review article it was determined
     that SCS decreases use of short-acting
     nitrates, improves quality of life, and
     increases exercise capacity. [Deer TR.
     Spinal cord stimulation for the treatment of
     angina and peripheral vascular disease.
     Curr Pain Headache Rep. 2009;13(1):18-23.]
     C. Many follow-up studies have been published
     showing efficacy with short-term follow-
     ups such as 6 months. A recent 5 year
     follow-up of a randomized, controlled trial
     of SCS for CRPS revealed that 95% of
     patients would repeat the treatment for the
     same result. Aretrospective telephone questionnaire
     study was performed in 21 CRPS
     patients with average follow-up at 2.7 years.
     Reduced pain and improved quality of life
     was sustained at long-term follow-up.
     [Kemler MA, de Vet HC, Barendse GA, et al.
     Effect of spinal cord stimulation for chronic
     complex regional pain syndromes type I:
     five-year final follow-up of patients in a randomized controlled trial. J Neurosurg.
     2008;108(2):292-298.]
     D. SCS is effective for the treatment of sympathetically
     mediated pain.
     E. This is a false statement. Neuropathic pain
     has traditionally been considered an indication
     for SCS. Nociceptive pain is considered
     not amenable to treatment with SCS.

Question 44

675. Which of the following is not a relative contraindication
to SCS?
(A) Unresolved major psychiatric
comorbidity
(B) A predominance of nonorganic signs
(C) Spinal cord injury or lesion
(D) Alternative therapies with a risk to benefit
ratio comparable to that of SCS
remain to be tried
(E) Occupational risk

Answer 44

675. (C) In 2007, an article published an evidencebased
     literature review and consensus statement
     which addressed over 60 questions
     relating to clinical use of SCS. Spinal cord
     injury or lesion, is an etiology of neuropathic
     pain and is an indication for SCS. Certain occupations
     such as an electrician’s are considered
     a relative contraindication to SCS therapy.

Question 45

676. Which of the following statements is most
     accurate regarding cost-effectiveness of SCS?
     (A) Nobody opines of its cost-effectiveness
     and the issue has not been addressed in
     literature
     (B) The literature is clear and consistent;
     SCS is not cost-effective
     (C) Although published conclusions may
     vary, a consensus of professionals has
     determined that SCS stimulation is not
     cost-effective
     (D) Although published conclusions may
     vary, a consensus of professionals has
     determined that SCS is cost-effective for
     certain indications
     (E) All published literature on the topic
     concludes that SCS is cost-effective

Answer 45

676. (D) Some published articles concluded that
     SCS is cost-effective. Some have concluded that
     SCS is not cost-effective, at least in certain
     patient populations. Variation may relate to
     specific parameters and patient inclusions in
     the study. Recent practice parameters concluded
     that SCS is cost-effective in the treatment of
     failed back surgery syndrome and CRPS and
     might be cost-effective in the treatment of other
     neuropathic pain indications. Furthermore it
     was concluded that cost-effectiveness can be
     optimized by adjusting stimulation parameters
     to prolong battery life, by minimizing complications,
     and by improving equipment
     design. [Mekhail NA, Aeschbach A, Stanton-
     Hicks M. Cost benefit of neurostimulation for
     chronic pain. Clin J Pain 2004;20(6):462-468.
     Klomp HM, Steyerberg EW, van Urk H,
     et al. Spinal cord stimulation is not cost-effective
     for non-surgical management of critical
     limb ischemia. Eur J Vasc Endovasc Surg.
     2006;31(5): 500-508.
     North R, Shipley J, Prager J, et al. Practice
     parameters for the use of spinal cord stimulation
     in the treatment of chronic neuropathic
     pain. Pain Med 2007;8(suppl 4):S200-S275.]

Question 46

677. Which of the following are specifications for
current SCS systems?
(A) Constant voltage, pulse width up to
2000 milliseconds
(B) Constant current, volume less 10 cm3
(volume less than a standard matchbook)
(C) Constant resistance, pulse width up to
1000 milliseconds, cordless recharging
(D) Constant current, pulse width up to
1000 milliseconds, cordless recharging
(E) Constant current and constant resistance,
cordless recharging, pulse width
up to 1000 milliseconds

Answer 46

677. (D)
     A. One of the three commonly used manufacturers
     does use a constant voltage technology.
     None of the three manufacturers have
     a system allowing pulse width much over
     1000 milliseconds.
     B. Two of the three commonly used manufacturers
     do use a constant current technology.
     Although battery sizes as small as
     22 cm3 are available with two companies,
     no company currently has a battery
     smaller than that in current clinical usage.
     This may change in the near future.
     C. No SCS system relies on maintaining constant
     resistance. Resistance is not in the
     physician’s control and varies with factors
     such as scar tissue formation. Cordless
     recharging is available with several manufacturers’
     systems.
     D. This is a specification set that is currently
     available. Aconstant voltage system is also
     now available with pulse widths up to
     1000 milliseconds.
     E. Maintaining both constant current and
     constant resistance would not be achievable
     because resistance is not a controllable
     factor. Voltage, current, and resistance vary
     according to Ohm’s law: voltage = current ×
     resistance.
     New batteries have reached the market
     including ones with constant voltage,
     pulse width of 1000 milliseconds, and battery
     size of about 22 cm3.

Question 47

678. Which of the following is true?
     (A) Dorsal column pathways do not play a
     role in visceral pain and therefore there
     is no role of SCS for visceral pain
     (B) Pelvic pain has been demonstrated to
     consistently fail treatment with SCS
     (C) The midline dorsal column pathway has
     been the proposed target for stimulation
     for chronic visceral pain
     (D) Pelvic pain stimulation can best be
     achieved by first targeting the S2 foramen
     in a retrograde approach
     (E) There is no therapeutic potential for
     treatment of chronic visceral pelvic pain
     with SCS

Answer 47

678. (C)
     A. Dorsal column pathways have been
     demonstrated to play a role in transmission
     of visceral pain.
     B. Case reports have been published showing
     successful treatment of pelvic pain with
     SCS. One such report was a case series of
     six patients with pelvic pain of multiple
     diagnoses all treated successfully with
     SCS. Diagnoses included vulvar vestibulitis,
     endometriosis, pelvic adhesions,
     uterovaginal prolapsed, and vulvodynia.
     C. Midline myelotomy may relieve visceral cancer
     pain. This is a deep pathway and therefore
     a tightly spaced lead which can drive the
     stimulation deeper would be advantageous
     for attempted SCS for visceral pain.
     D. The stimulation “sweet spot” for pelvic
     pain has been reported to be around T12.
     E. Case study evidence supports the role for
     SCS for chronic visceral pelvic pain.
     Further well-designed studies are needed.

Question 48

679. Which of the following is the best answer
regarding lead geometry and spacing?
(A) The goal of SCS in treatment of bilateral
lower extremity neuropathy pain is
most frequently to stimulate the dorsal
roots rather than the dorsal columns
(B) Tight lead spacing increases the ratio of
dorsal column to dorsal root stimulation
(C) Too much stimulation of the dorsal
columns results in motor side effects
(D) As the distance from the contact to the
spinal cord increases, stimulation
becomes more specific for the dorsal
columns as opposed to the dorsal
roots
(E) Rostrocaudal contact size (contact
length) is less important than lateral
contact size (contact width)

Answer 48

679. (B)
     A. The dorsal columns contain the primary
     cutaneous afferents which are the usual
     targets. Stimulation of a nerve root will
     lead to segmental paresthesia and will not
     be likely to encompass the entire area of
     the bilateral lower extremity neuropathic
     pain.
     B. This is a correct statement and was supported
     by computer-modeled analysis.
     C. To the contrary, motor side effects usually
     indicates stimulation of dorsal roots rather
     than the dorsal column.
     D. This statement is incorrect because as the
     contact to spinal cord distance increases,
     stimulation becomes less specific and
     there is an increased chance of dorsal root
     stimulation.
     E. This is a false statement because fiber
     type preference is more sensitive to rostrocaudal
     contact size then to lateral contact
     size.

Question 49

680. The gate control theory is one postulated mechanism
     of action for SCS. Which of the following
     is the most accurate application of SCS to this
     postulated mechanism of action?
     (A) Activation of large-diameter afferents
     thereby “closing the gate”
     (B) Activation of large-diameter afferents
     thereby “opening the gate”
     (C) Activation of small-diameter afferents
     thereby “closing the gate”
     (D) Activation of small-diameter afferents
     thereby “opening the gate”
     (E) Activation of both large- and smalldiameter
     afferents equally

Answer 49

680. (A) Ronald Melzack and Patrick Wall published
     the landmark gate control theory in the
     journal Science in 1965. According to this theory
     as published in 1965, large and small fibers
     project to the substantia gelatinosa. The substantia
     gelatinosa exerts an inhibitory effect on
     afferent fibers. Large fibers increase the
     inhibitory effect, “close the gate,” and decrease
     the afferent pain signal. Small fibers decrease
     the inhibitory effect, “open the gate,” and
     increase the afferent pain signal.
     This gate control theory is commonly
     cited as the mechanism of action of SCS, but a
     2002 review concludes that other mechanisms
     must also play a role. [Oakley JC, Prager JP.
     Spinal cord stimulation: mechanisms of
     action. Spine. 2002;27(22):2574-2583.
     Melzack R, Wall PD. Pain Mechanisms: a
     new theory. A gate control system modulates
     sensory input from the skin before it evokes pain perception and response.

Question 50

681. Which of the following is most accurate regarding
     indications for SCS?
     (A) Nociceptive pain is traditionally considered
     a better indication than neuropathic
     pain
     (B) Receptor mediated pain is traditionally
     considered a better indication than neurogenic
     pain
     (C) SCS tends to more effectively treat sympathetically
     mediated pain than pain of
     the somatic nervous system
     (D) Intractable angina is not effectively
     treated with SCS
     (E) Persisting neuropathic extremity pain
     following spinal surgery is a better indication
     than pain of CRPS

Answer 50

681. (C)
     A. The opposite of the given statement would
     be more accurate (ie neuropathic pain is
     traditionally considered a better indication
     than nociceptive pain).
     B. This is a restatement of (A). The term
     “receptor mediated” is substituted for and
     synonymous with nociceptive. The term
     “neurogenic” is substituted for and synonymous
     with neuropathic.
     C. Multiple authors have described beneficial
     results of SCS for sympathetic-mediated
     pain [Stanton-Hicks M. Complex regional
     pain syndrome: manifestations and the role
     of neurostimulation in its management. J
     Pain Symptom Manage. 2006;31(suppl 4):
     S20-S24.
     Kumar K, Nath RK, Toth C. Spinal cord
     stimulation is effective in the management of
     reflex sympathetic dystrophy. Neurosurgery.
     1997;40(3):503-508.
     Harke H, Gretenkort P, Ladlef HU, et al.
     Spinal cord stimulation in sympathetically
     maintained complex regional pain syndrome
     type I with severe disability. A prospective
     clinical study. Eur J Pain. 2005;9(4):363-373.]
     D. This is a false statement as some consider
     intractable angina to be the pain most
     effectively treated with SCS, with up to
     90% effectiveness.
     E. Both persisting neuropathic pain of the
     extremity following spinal surgery and
     pain of CRPS are indications for SCS.
     However, persisting neuropathic extremity
     pain following spinal surgery is not a better
     indication. In fact, SCS is considered by
     some to be a more effective treatment of
     CRPS than persisting neuropathic pain of
     the extremity following spinal surgery.

Question 51

682. Which of the following correctly arranges
     intraspinal elements from highest to lowest
     conductivity?
     (A) CSF, longitudinal white matter, gray
     matter, transverse white matter, dura
     (B) Longitudinal white matter, gray matter,
     CSF, transverse white matter, dura
     (C) Longitudinal white matter, transverse
     white matter, dura, gray matter, CSF
     (D) Gray matter, longitudinal white matter,
     transverse white matter, CSF, dura
     (E) Dura, transverse white matter, gray
     matter, longitudinal white matter, CSF

Answer 51

682. (A) The conductivity of intraspinal elements has
     clinical significance. While some tissues have
     sufficient conductivity to allow stimulation to
     reach afferent fibers and initiate a depolarization,
     other tissues provide an insulation-like
     effect to protect visceral organs. One would not have to know the actual conductivities of
     intraspinal elements to answer this question.

Question 52

683. Which of the following is the most accurate
     explanation why thoracic level cord stimulator
     leads do not commonly stimulate intrathoracic
     structures such as the heart?
     (A) Thoracic placement of SCS leads is contraindicated
     and is therefore not a clinically
     used technique
     (B) The CSF is highly conductive and therefore
     diverts the stimulation into a different
     direction
     (C) The stimulation is very specific for neural
     tissues rather than visceral tissues
     (D) The dura has a very low conductivity
     and therefore insulates visceral structures
     from stimulation
     (E) The vertebral bone has a very low conductivity
     and therefore insulates visceral
     structures from stimulation

Answer 52

683. (E)
     A. Thoracic placement of SCS leads is very
     common. Contacts are often placed at the
     T8 level for instance for treatment of lower
     extremity pain.
     B. While it is true that CSF is highly conductive,
     it does not divert the stimulation
     away from thoracic structures.
     C. While it is true that various fibers have differing
     thresholds for recruitment, a negatively
     charged electrode (a cathode) will
     cause a neuron to become more electrically
     charged and depolarized, regardless of the
     tissue of origin.
     D. It is true that dura has a very low conductivity
     similar to vertebral bone. However,
     because the dura is so thin, it does not present
     significant resistance. This should also
     be instinctively false because if the dura
     insulated structures from stimulation, then
     it would not be possible to stimulate the
     neural structures of the spinal cord.
     E. This is a true statement. The conductivity
     of vertebral bone is very low compared to
     other intraspinal tissues.

Question 53

684. Which of the following best describes the proposed
     mechanism of action of SCS?
     (A) There is evidence that during SCS large
     myelinated afferent fibers are activated
     in an antidromic manner
     (B) There is a measurable increase in
     endogenous opioids in response to SCS
     (C) Spinothalamic tract activation during
     SCS leads to an analgesic effect
     (D) SCS causes an inhibition of ascending
     and descending inhibitory pathways
     (E) SCS has no effect on abnormal A-β
     activity

Answer 53

684. (A)
     A. Antidromic responses can be measured at
     the sural nerve during SCS. This was
     described in a 2002 review of SCS mechanisms
     and also demonstrated in 21 measurements
     in 16 patients in another study in
685. [Oakley JC, Prager JP. Spinal cord
     stimulation: mechanisms of action. Spine.
     2002;27(22):2574-2583.
     Buonocore M, Bonezzi C, Barolet G.
     Neurophysiological evidence of antidromic
     activation of large myelinated fibers in
     lower limbs during spinal cord stimulation.
     Spine. 2008;33(4):E90-E93.]
     B. SCS efficacy is not reversed by naloxone
     and there is no relation of SCS to endogenous
     opioid levels.
     C. This would be a mechanism of algesic effect.
     In fact, one of the proposed mechanisms
     of action of SCS is spinothalamic tract
     inhibition.
     D. This would be a mechanism of algesic effect.
     In fact, one of the proposed mechanisms of
     action of SCS is activation of ascending and
     descending inhibitory pathways. On review
     of the mechanisms of action of SCS, one possible
     mechanism of action was cited as activation
     of supraspinal loops relayed by the
     brain stem or thalamocortical systems
     resulting in ascending and descending inhibition.
     [Oakley JC, Prager JP. Spinal cord
     stimulation: mechanisms of action. Spine.
     2002;27(22):2574-2583.]
     E. According to a 2002 review, the predominant
     effect of SCS is on abnormal activity in
     A-β neurons related to the perception of
     pain. [Oakley JC, Prager JP. Spinal cord
     stimulation: mechanisms of action. Spine.
     2002;27(22):2574-2583.]

Question 54

685. Which of the following is true?
     (A) Phenol theoretically carries a higher risk
     for neuroma formation than alcohol
     (B) Radiofrequency ablation is particularly
     useful for field neurolysis
     (C) Phenol is a particularly useful neurolytic
     agent for localized targets
     (D) Alcohol is a particularly useful neurolytic
     agent because there is no pain
     upon injection
     (E) Phenol causes wallerian degeneration

Answer 54

685. (A) Because phenol destroys the basal neurolemma,
     wallerian degeneration does not
     occur and there is a higher risk for neuroma
     formation. Lesion size is more difficult to precisely
     control with a liquid neurolytic injectate
     as compared to radiofrequency ablation in
     which the lesion size occurs in a known distance
     around the needle tip. On the other hand,
     when a field lesion is needed, a liquid neurolytic
     may be a more practical approach.

Question 55

686. Which of the following is most painless upon
delivery?
(A) Phenol
(B) Alcohol
(C) Radiofrequency
(D) Cryoanalgesia
(E) Cold knife excision of a nerve

Answer 55

686. (A) Phenol is not painful upon injection

whereas the other listed techniques are painful.

Question 56

687. Which of the following neurolytic techniques is
most concerning for the side effect of
arrhythmia?
(A) Laser neurolysis
(B) Cryoanalgesia
(C) Radiofrequency
(D) Alcohol
(E) Phenol

Answer 56

687. (E) Phenol is concerning for arrhythmias, seizure,
     destruction of Dacron grafts, vasospasm, and
     vascular proteins. Alcohol is more concerning
     for vasospasm than phenol. Caution when considering
     radiofrequency neurolysis includes
     interference with electrical implants. Risks of
     cryoneurolysis include frostbite to adjacent
     tissues.

Question 57

688. Which of the following statements is the most
     accurate comparison of radiofrequency ablation
     and cryoablation?
     (A) Cryoanalgesia probes are generally
     smaller in diameter than the large-diameter
     probes used for radiofrequency
     procedures
     (B) One disadvantage of cryoanalgesia technique
     is the operator must support a
     heavier instrument while maintaining
     the probe tip in accurate position
     (C) The cryolesion and the radiofrequency
     lesion are similar in size
     (D) Cryoanalgesia and radiofrequency
     lesion techniques have equal precision
     capability
     (E) Cryoanalgesia is inferior to radiofrequency
     ablation because cryoanalgesia
     causes wallerian degeneration

Answer 57

688. (B)
     A. Cryoanalgesia probes are generally larger
     in diameter than radiofrequency probes.
     Current cryoanalgesia probes range in size
     from 1.4 to 2 mm. The 1.4-mm cryoprobe is used with a 14- or 16-gauge catheter. A
     2-mm cryoprobe is inserted into a 12-
     gauge catheter. Radiofrequency procedures
     are commonly performed using a
     22-gauge needle. A22-gauge needle has an
     outside diameter of about 0.7 or 0.72 mm.
     B. The cryoanalgesia instrument may be cumbersome
     to support while simultaneously
     maintaining accurate needle-tip position.
     The smaller and lighter probes used with
     radiofrequency lesioning machines are less
     cumbersome to manage.
     C. The ice ball formed at the tip of the cryoprobe
     is larger in size than what can be
     obtained with radiofrequency lesions.
     D. Because of the smaller obtainable lesion
     size with the radiofrequency techniques, a
     more precise target lesion can be achieved.
     E. Both cryoanalgesia and radiofrequency
     techniques cause wallerian degeneration
     and therefore less risk for neuroma formation
     compared to phenol.

Question 58

689. Which of the following is most accurate regarding
     the electric field generated at the tip of a
     radiofrequency electrode?
     (A) Flat conductors generate larger, stronger
     electric fields than round conductors
     (B) With round conductors, the charge density
     is directly proportional to the radius
     of the circle
     (C) The electric field around a radiofrequency
     cannula is more dense around
     the exposed shaft and becomes less
     dense at the tip
     (D) Voltage, current, and power are the
     three basic variables governing formation
     of heat surrounding a radiofrequency
     cannula tip
     (E) The heat lesion formed around the
     radiofrequency cannula is slightly pearshaped
     with the base of the pear around
     the proximal end of the active tip and less
     projection of the heat at the needle tip

Answer 58

689. (E)
     A. Round conductors generate larger, stronger
     electric fields than flat conductors.
     B. With round conductors, the charge density
     is inversely proportional to the radius of
     the circle.
     C. The electric field around the exposed shaft
     of a radiofrequency cannula is less dense
     and becomes more dense at the tip.
     D. The three basic variables of electric current
     are voltage, current, and resistance. These
     are the three factors in Ohm’s law.
     E. Although the electric field is less dense
     around the shaft but more dense around
     the tip of the cannula, the shape of the heat
     lesion is different. The heat lesion is
     slightly larger around the proximal end of
     the active tip and smaller at the needle tip.

Question 59

690. Which of the following is the most accurate
     statement regarding neuraxial neurolysis?
     (A) Phenol has significant proven benefit
     over alcohol
     (B) The technique is 100% efficacious
     (C) The average pain relief is less than
     6 months
     (D) Bladder paresis and motor weakness
     occurs in close to 100% of those treated
     with neuraxial neurolysis
     (E) Epidural neurolysis has a proven favorable
     risk to benefit ratio compared to
     subarachnoid neurolysis

Answer 59

690. (C)
     A. While phenol may be useful for its hyperbaric
     property, there is no clear benefit versus
     alcohol.
     B. Excellent results are reported in 50% to
     75% of patients.
     C. The average duration of pain relief after
     neuraxial neurolysis has been reported at
     4 months.
     D. Bladder paresis and motor paresis occurs
     in approximately 5% of treated patients.
     Bowel paresis occurs in approximately 1%
     of treated patients.
     E. There is no evidence for greater efficacy or
     lower risk for epidural neurolysis compared
     to subarachnoid neurolysis.

Question 60

691. While performing an intradiscal radiofrequency
     procedure using a posterior-oblique approach,
     the needle tip is advanced into the annulus
     fibrosus using fluoroscopic guidance. Impedance
     is noted. The needle tip is then advanced a little
     further. Adrop in impedance is noted. Which of
     the following is the most likely explanation?
     (A) Malfunction of radiofrequency machine
     (B) Needle-tip entry into CSF
     (C) Needle-tip entry into spinal cord
     (D) Needle-tip has dry blood on it
     (E) Needle-tip entry into nucleus pulposus

Answer 60

691. (E) From the described approach, further
     advancement of the needle tip should either
     remain in annulus fibrosis or enter the next
     tissue layer, nucleus pulposus. CSF and spinal
     cord are not expected in the described trajectory.

Question 61

692. Which of the following is appropriate safety
     consideration when performing a radiofrequency
     ablation procedure?
     (A) Motor stimulation is not needed if
     meticulous fluoroscopic technique is
     used
     (B) A radiofrequency probe should be the
     length of the cannula or shorter, but
     never longer than the cannula
     (C) The pain physician should always turn
     off a patient’s sensing pacemaker prior
     to a radiofrequency procedure
     (D) Complications during radiofrequency
     ablation are rare and need not be considered
     prior to the procedure
     (E) A SCS should be turned off prior to a
     radiofrequency procedure

Answer 61

692. (E)
     A. Motor stimulation can detect and prevent
     unexpected improper heat lesioning. For
     example, a break in the insulation of the
     needle shaft can allow current to leak into
     unexpected tissues.
     B. The radiofrequency probe should extend
     to the tip of the cannula. Too short of a
     radiofrequency probe will result in temperature
     measurements that are lower than
     the actual tissue temperature. This is especially
     concerning as a radiofrequency unit
     with automatic temperature control would
     increase the output in this situation, leading
     to even higher tissue temperatures.
     C. It is usually best to consult a cardiologist
     prior to radiofrequency procedures when
     the patient has a pacemaker. If the pacemaker
     is a sensing pacemaker, then changing
     the setting to a fixed rate is suggested.
     D. It is best to prevent complications rather
     than treat complications.
     E. The SCS should be turned off prior to
     radiofrequency procedures.

Question 62

693. Coulomb per kilogram (C/kg) is
(A) the unit used to measure electrical
charge produced by x- or γ-radiation
similar to previous roentgen unit
(B) used to measure dose equivalent
(C) the daily radiation exposure per kilogram
of body weight
(D) the intensity of radiation
(E) used to measure the amount of radiation
absorbed

Answer 62

693. (A) Coulomb per kilogram is used to measure
     electrical charge produced by x- or γ-radiation
     similar to previous roentgen unit in a standard
     volume of air by ionization. Sievert (Sv) is used
     to measure dose equivalent

Question 63

694. Gray (Gy) is used to measure
(A) yearly background exposure
(B) absorbed dose
(C) dose equivalent
(D) daily radiation exposure
(E) yearly radiation exposure

Answer 63

694. (B) Gray (Gy) measures absorbed dose (energy
     deposited per unit mass). One gray is equal to
     1 J/kg.

Question 64

695. Maximum total permissible dose equivalents
(in mSv) for a year is
(A) 75 mSv
(B) 100 mSv
(C) 150 mSv
(D) 50 mSv
(E) 25 mSv

Answer 64

695. (D) Individual doses may vary (eg, eye 12.5 mSv).

Question 65

696. How low should a clinician’s hourly radiation
exposure be?
(A) Less than 0.01 mSv/h
(B) Less than 0.05 mSv/h
(C) Less than 0.15 mSv/h
(D) As low as reasonably achievable
(E) Less than 0.25 mSv/h

Answer 65

696. (D) As low as reasonably achievable is also
     known as ALARA (As low as reasonably
     achievable).

Question 66

697. Most operator exposure during fluoroscopically
guided blocks is when
(A) the lateral views are taken
(B) the x-ray tube is above the patient
(C) the patient is obese
(D) the anteroposterior views are taken
(E) none of the above

Answer 66

697. (B) The x-ray tube above the patient provides
     most operator exposure because the scattered
     beam is greater at the entrance site of the skin
     compared to exit site.

Question 67

698. The intensity of scattered beam is greater at the
     radiation entrance on the skin than exit site
     (A) 3 times
     (B) 10 times
     (C) 30 times
     (D) 985 times
     (E) 1000 times

Answer 67

698. (D) As the intensity of scattered beam is greater
     at the radiation entrance on the skin than exit
     site the radiation exposure to the operator is
     significantly increased when the x-ray tube is
     above the patient.

Question 68

699. Average patient radiation exposure dose
     during pain procedures is
     (A) 10 times less than during angiography
     (B) same as during angiography
     (C) 10 times more than during angiography
     (D) less than computed tomographic (CT)
     scanning
     (E) 20 times more than during angiography

Answer 68

699. (C) The patient radiation doses of angiography
     are on the other hand 10 times higher than gastrointestinal
     fluoroscopy and CT imaging.

Question 69

700. Radiation dose to the patients and medical personnel
can be reduced by
(A) decreasing the distance between the
image intensifier and the patient
(B) increasing the distance between the
image intensifier and the patient
(C) using continuous fluoroscopy
(D) oblique views
(E) none of the above

Answer 69

700. (A) Oblique views can also increase the radiation

to the patients and operators.

Question 70

701. Personnel radiation protection can be achieved
by
(A) lead aprons
(B) glasses
(C) increased distance from the x-ray
(D) all of the above
(E) none of the above

Answer 70

701. (D) Lead aprons contain equivalent of 0.5 mm
     of lead and can reduce the radiation exposure
     by 90% from scatter.

Question 71

702. Lead aprons should be always hung:
(A) So that space is saved
(B) As the lead can be broken if folded
(C) They can be safely folded as well
(D) So they can be conveniently available
(E) None of the above

Answer 71

702. (B) Broken lead in aprons can provide suboptimal

radiation protection.

Question 72

703. A patient with severe spasticity is a candidate
     for an intrathecal baclofen pump. He and his
     family have heard that “these pumps get
     infected.” How do you respond?
     (1) Device-related infection is the most
     common, potentially reducible, serious
     adverse event associated with intrathecal
     pumps
     (2) The majority of infections occur at the
     lumbar site
     (3) Management of infections associated
     with drug-delivery systems usually
     involves the administration of antibiotics
     and explantation of the device
     (4) The chances of the pump getting
     infected are minimal and the family
     should only focus on the benefits that
     the device provides

Answer 72

703. (B) The diagnosis of an implantable devicerelated
     surgical-site infection is definitively
     made by identification or culture of microorganisms
     (most commonly bacteria) or both on
     specimens from a clinically suspected surgical
     wound or implant site. Signs of wound infection
     include fever, erythema, edema, pain,
     wound exudates, poor healing, or skin erosion
     at the implant site. Meningismus indicates CSF
     involvement.
704. Infections related to the implantation of a SCS
     or an intrathecal drug-delivery system is the
     most common, potentially reducible, serious
     adverse events associated with these devices.
705. In the comparison of drug-delivery devicerelated
     infections in multicenter studies the
     pump pocket was the site of infection
     between 57.1% and 80% of the time, the
     lumbar site was the infection location
     between 13% and 33% of the time, and
     meningitis was the infection between 10%
     and 14.3% of the time.
706. Management of infections associated with
     drug-delivery and SCS systems typically
     involves administration of antibiotics and
     explantation of the devices.
707. You should always worry about potential
     complications.
     The infection rates, based on the number of
     infections that occurred and the number of
     patients that were evaluated have varied from
     2.5% to 9.0% of implanted patients. The highest
     infection rate (9%), occurred in the 10-mL
     SynchroMed pump that was used in pediatric
     patients with spasticity of cerebral origin
     (n = 100), predominantly spastic cerebral palsy.
     The lowest infection rate, (2.5%), occurred in
     the group that received intrathecal recombinant
     methionyl human brain-derived neurotrophic
     factor (BDNF) to treat amyotrophic
     lateral sclerosis. 36 infections in 35 patients
     were described in a total of 700 patients (5%
     overall infection rate).

Question 73

704. When trialing intrathecal medication and placing
     intrathecal pumps, which of the following
     is considered good technique?
     (1) Antibiotics are given during the course
     of the trial, and for 7 to 10 days after
     permanent implant
     (2) If the entry point is above L2, the
     patient should be conversant, and the
     angle of entry should be as shallow as
     possible
     (3) Placing the patient in the lateral decubitus
     position with the hips flexed, and
     the knees bent
     (4) Electrocautery is now considered the
     gold standard for controlling bleeding

Answer 73

704. (A)
705. The most common antibiotics used are a
     third-generation cephalosporin or vancomycin.
     Intraoperatively, many physicians
     irrigate the wound with antibiotic
     solution. Adjustments to antibiotic regimens
     should be made based on the most
     common pathogens seen in the community
     and medical center.
706. In most instances the needle entry point
     into the intrathecal space is below L2.
     Sometimes, although rare, the entry point is
     at the level of the cord. If the entry point is
     above L2, the patient should be communicating
     with the physicians and nurses, and
     the angle of entry should be as small as
     possible. If any paresthesia is experienced,
     the needle should be removed and repositioned. Once the catheter is properly
     positioned, a purse-string suture should be
     fashioned to secure the tissue around the
     catheter. Then, an anchor should be used to
     fasten the catheter to fascia. Given recent
     studies on inflammatory masses at catheter
     tips, whether the distal end of the catheter
     should be placed near the supposed pain
     generator or not is still up for debate.
707. While the patient may be positioned prone
     for catheter placement, placing them in the
     lateral decubitus position precludes having
     to reposition them for pocket creation. The
     usual site for pump placement is the lateral
     anterior abdominal wall at the level of the
     umbilicus. The pump should be anchored
     in a manner to prevent flipping.
708. The physician should meticulously obtain
     proper hemostasis during the case. Small
     venous and arterial bleeders can be recognized
     by retracting the wound after antibiotic
     irrigation. Numerous techniques exist
     to obtain hemostasis:
     • Simple pressure
     • Sponges soaked in 3% hydrogen peroxide
     solution may be packed into the
     wound for 3 to 5 minutes (may be very
     helpful with small vessels)
     • Electrocautery for more pronounced
     bleeding [Note: overheating tissue can
     cause trauma or seroma formation,
     which can lead to delayed healing, dehiscence,
     or infection of the wound]
     • Suturing a vessel is still the gold standard
     A large sterile pressure dressing should be
     applied over the wound plus/minus an abdominal
     binder to reduce the risk of seroma formation
     and bleeding. Antibiotic ointment is also frequently
     used immediately over the incision; it
     may help in preventing the spread of infection.
     When considering dressing changes, the
     physician should be judicious—they can take
     place daily or only if the dressing is excessively
     saturated.

Question 74

705. Which of the following is (are) disease state(s)
     that are amenable to treatment by intrathecal
     drug-delivery system?
     (1) Intractable spasticity related to cerebral
     palsy and spinal cord injuries
     (2) Interstitial cystitis
     (3) Cancer-related syndromes
     (4) Rheumatoid arthritis

Answer 74

705. (E) In the early 1980s intrathecal drug-delivery
     was initiated for the treatment of intractable
     spasticity related to cerebral palsy and spinal
     cord injuries. This therapy eventually evolved
     to use in implacable cancer pain. Intrathecal
     preservative-free baclofen and morphine are
     FDAapproved for the treatment of moderate to
     severe spasticity and moderate to severe pain,
     respectively. A study in oncology patients
     showed a major improvement using intrathecal
     medication delivery in cancer pain versus thorough
     medical management in the areas of
     tiredness, level of consciousness, and survival.
     [Smith TJ, Staats PS, Deer T et al. Randomized
     clinical trial of an implantable drug delivery
     system compared with comprehensive medical
     management for refractory cancer pain:
     impact on pain, drug-related toxicity, and survival.
     J Cli. 2002;20(19):4040-4049.]
     Other disease states found to be responsive to
     intrathecal drug-delivery systems are
     • Spinal stenosis
     • Radiculitis
     • Compression fractures
     • Spondylosis
     • Spondylolisthesis
     • Foraminal stenosis
     • Arachnoiditis
     • Syrinx
     • Ankylosing spondylitis
     • Spinal cord trauma
     • Spinal infarction
     • Paraplegia
     • Cauda equina syndrome
     • Peripheral neuropathy
     • Phantom limb pain
     • Rheumatoid arthritis
     • Radiation neuritis
     • Postherpetic neuralgia
     • Postthoracotomy syndrome
     • Interstitial cystitis
     • Chronic pain of the abdomen and pelvis

Question 75

706. A 56-year-old female who had an intrathecal
     pump placed secondary to metastatic renal cell
     carcinoma is having pain equivalent to a 6 on the visual analog scale (VAS). What is the
     proper titration regimen?
     (1) Increase dose 10% to 25% over 3 to 4 days
     (2) Increase dose 25% to 50% daily
     (3) Hourly rates should be adjusted 35% to
     50% twice daily until pain relief is
     achieved
     (4) A therapeutic bolus should be considered

Answer 75

706. (C) Patients with a VAS pain scale of 7 to 10 may
     necessitate inpatient/hospice care for pain treatment.
     For those who wish to remain in a home
     environment, a 50% to 100% increase in their
     medication dose may be in order. Therapeutic
     boluses should be administered to an end point of pain relief, as well as daily medication adjustments
     to the same end point. Significant, abrupt
     increase in medication may cause severe side
     effects, and physicians should be available in
     the first 12 hours following the modification, to
     manage potential complications.

Question 76

707. A 52-year-old female with pancreatic cancer
     and her family are trying to decide between
     continued medical management for pain versus
     an intrathecal drug-delivery system. Believing
     that this patient would most benefit from an
     intrathecal pump, you tell them that studies
     have shown that
     (1) overall toxicity is better with intrathecal
     pumps
     (2) pain relief is better with intrathecal pumps
     (3) intrathecal pumps improve fatigue and
     level of consciousness in patients versus
     medical management
     (4) there is a trend to increased survival in
     patients who have intrathecal pumps
     versus those continuing with medical
     management

Answer 76

707. (E) A multicenter, randomized, prospective
     study compared intrathecal drug delivery to
     comprehensive medical management. The
     results showed a statistically significant advantage
     of intrathecal pumps on
     • Overall toxicity
     • Pain relief
     • Fatigue and level of consciousness
     • Improved survivability
     The study hinted that more patients with
     moderate to severe cancer pain should be considered
     for intrathecal pumps. [Smith TJ,
     Staats PS, Deer T et al. Randomized clinical
     trial of an implantable drug delivery system
     compared with comprehensive medical management
     for refractory cancer pain: impact on
     pain, drug-related toxicity, and survival. J
     Clin. 2002;20(19):4040-4049.]

Question 77

708. Third occipital nerve
     (1) innervates C2-3 facet joint
     (2) curves around superior articular process
     of the C2 vertebrae
     (3) curves around superior articular process
     of the C3 vertebrae
     (4) innervates C3-4 facet joint

Answer 77

708. (B) The third occipital headache is caused by
     third occipital neuralgia. The TON innervates
     the C2-3 zygapophysial joint and curves
     around the superior articular process of the C3
     vertebral body. Among patients with whiplash
     injuries, third occipital headache is common,
     with a prevalence of 27%.

Question 78

709. For the peripheral stimulation of the occipital
     nerve
     (1) the electrode should be parallel to the
     occipital nerve in the occipital area of
     the scull
     (2) only a “paddle-” type electrode should
     be used
     (3) the entry site of the introducer needle
     should be at T1-T2 level
     (4) the electrode should be placed subcutaneously
     at the C1-C2 level

Answer 78

709. (D) The occipital nerve stimulator is a useful
     tool in managing occipital neuralgia. Although
     paddle electrodes are not necessary they may
     provide better coverage than the regular
     electrode.

Question 79

710. T2 and T3 sympathetic block
     (1) is used for treatment of upper extremity
     complex regional pain syndrome (CRPS)
     (2) will help by denervating the Kuntz
     nerves
     (3) can lead to pneumothorax
     (4) should avoid radiofrequency of T2 and
     T3 sympathetic ganglia

Answer 79

710. (A) T2 and T3 sympathetic blocks are a useful
     tool in conjunction with stellate ganglion block
     for upper extremity CRPS. By blocking them,
     Kuntz nerves will be blocked that bypass the
     stellate ganglion. RF denervation of these
     nerves may lead to prolonged pain relief.

Question 80

711. Vertebroplasty may be indicated for
     (1) multiple myeloma
     (2) chronic compression fractures of
     vertebral body
     (3) osteolytic metastatic tumors
     (4) facet arthropathy

Answer 80

711. (A) Vertebroplasty is best used for acute vertebral
     fracture where bone cement is percutaneously injected into a fractured vertebra in order to
     stabilize it. Alternatively, kyphoplasty involves
     placement of a balloon into a collapsed vertebra,
     followed by injection of bone cement to
     stabilize the fracture. It is not clear if one procedure
     has an advantage over the other. Both
     procedures may obtain almost immediate pain
     relief. And they are indicated for painful compression
     fractures because of osteoporosis and
     metastatic tumors.

Question 81

712. Complications from vertebroplasty include
     (1) pulmonary embolus
     (2) intradiscal leak of polymethyl
     methacrylate
     (3) paraplegia
     (4) psoas muscle leak of polymethyl
     methacrylate and femoral neuropathy

Answer 81

712. (E) Complications from vertebroplasty can be
     serious. Intravascular injection of polymethyl
     methacrylate can lead to pulmonary embolus
     and spinal cord damage and leak into intrathecal
     space can cause spinal cord injury. Lumbar
     procedures may lead to leak into psoas muscle
     and femoral neuropathy.

Question 82

713. Which of the following is (are) correct with
regards to piriformis muscle injection?
(1) Should be done at medial part of a
muscle
(2) Botox can be used
(3) Nerve stimulation may aid in muscle
location
(4) Identification of the muscle can be done
through rectal examination

Answer 82

713. (E) Piriformis injection should be done in the
     medial part of a muscle since the lateral part
     contains more ligaments. If injection of local
     anesthetics and steroids provides short-term
     pain relief only, the injection of botulinum toxin
     type Amay provide longer pain relief. The use
     of nerve stimulator, fluoroscopy, and contrast
     administration may help to assure proper
     needle placement. Tenderness over the piriformis
     muscle, positive Pace and Freiberg signs
     and rectal examination can be helpful in examining
     the piriformis muscle

Question 83

714. SI joint pain
     (1) is transmitted by the S1-S4 levels of
     spinal nerves
     (2) has been treated by the SI joint fusion
     (3) can be relieved by blind steroid
     injections
     (4) is transmitted by L4 medial branch, L5
     dorsal ramus, and S1-3 lateral branches

Answer 83

714. (D)
715. The innervation of the SI joint is from L4
     medial branch, L5 dorsal ramus, S1, S2, and
     S3 lateral branches. Some authors also state
     that the L3 medial branch may be involved.
716. SI joint fusion is used only in cases where
     serious anatomical problems (eg, fracture)
     are present in addition to pain.
717. SI joint injection should be done under fluoroscopic
     guidance to assure accuracy of
     needle placement.

Question 84

715. Celiac plexus block can be performed by
     (1) anterior approach
     (2) retrocrural approach
     (3) anterocrural approach
     (4) lateral approach

Answer 84

715. (B)
716. Anterior approach was initial approach
     described for blocking celiac plexus. Its
     advantage is that patient can be in more
     comfortable, supine position.
717. Although the retrocrural block may partially
     block the nerve supply to the celiac plexus
     actually blocks the splanchnic plexus.
718. Anterocrural approach is done with patient
     in prone position using one or two needles.
     Transaortic and transdiscal variation of this
     approach has been published as well.
719. Lateral approach is not used for celiac
     plexus block.

Question 85

716. Ganglion impar block
     (1) is indicated for testicular pain
     (2) is indicated for sympathetically maintained
     pain in perineal area
     (3) is best performed by anococcygeal
     approach
     (4) can be complicated by perforation of
     rectum

Answer 85

716. (C)
717. Testicular pain is treated by ilioinguinal
     block or lumbar sympathetic block.
718. Ganglion impar is the most caudal sympathetic
     ganglion.
719. The ganglion impar is located at the level of
     the sacrococcygeal junction that marks the termination
     of the paired paravertebral sympathetic
     chains. Initial approach described was
     through anococcygeal ligament. However, the
     trans-sacrococcygeal approach seems much
     safer way to perform this procedure.
720. Perforation of rectum may occur in particular
     if anococcygeal approach is used.

Question 86

717. With cervical interlaminar epidural steroid
     injection
     (1) loss of resistance technique can be inaccurate
     in up to 50% cases
     (2) unilateral medication spread can be
     achieved in 50% cases
     (3) contrast spread should be checked in
     lateral views
     (4) transforaminal approach is safer than
     interlaminar

Answer 86

717. (A)
718. As a result of discontinuous ligamentum
     flavum the loss of resistance is often inaccurate
     in cervical levels and more often in
     comparison to lumbar levels (30%).
719. The fluoroscopic guidance should be used
     and medication should be deposited ipsilateral
     to the pathology.
720. Final needle advancement and contrast
     spread should be first checked in lateral fluoroscopic
     views.
721. Transforaminal approach (most likely
     because of intravascular particulate steroid
     uptake) can lead to serious complications
     such as spinal cord infarction, quadriplegia,
     and death.

Question 87

718. Which of the following includes complication(
     s) of intrathecal pump?
     (1) Granuloma formation
     (2) CSF leak
     (3) Pump rotation
     (4) Hormonal imbalance

Answer 87

718. (E)
719. Granuloma formation can occur at the tip
     of the intrathecal catheter and can lead to
     serious complications including spinal cord
     injury.
720. CSF leak is a relatively common complication
     of intrathecal pump placement.
721. Pump rotation can cause kinking of the
     catheter and symptoms of increased pain
     and withdrawal.
722. Intrathecal opioids can lead to serious hormonal
     changes including weight gain.

Question 88

719. In relation to increased pain in patient with
intrathecal opioid delivery which of the following
is (are) true?
(1) It can mean progression of disease
(2) Catheter kink should be considered
(3) One should look for withdrawal
symptoms
(4) Opioids should be increased first

Answer 88

719. (A) Increased pain, in particular with withdrawal
     symptoms should be considered as a
     pump failure and treated promptly.

Question 89

720. Which of the following is (are) drug(s) used in decompressive neuroplasty?
     (1) Hyaluronidase
     (2) Hypertonic saline
     (3) Steroids
     (4) Local anesthetics

Answer 89

720. (E) Combination of hyaluronidase and hypertonic
     saline seems to increase the duration of
     procedure effect. Intrathecal injection of hypertonic
     saline can lead to serious complications
     and should be performed carefully.

Question 90

721. SCS been used for the treatment of
     (1) interstitial cystitis
     (2) postlaminectomy syndrome
     (3) CRPS
     (4) sympathetically mediated pain

Answer 90

721. (E) Traditional indications for SCS include postlaminectomy
     syndrome and CRPS. Indications
     have been expanding. Intestinal cystitis is now
     a commonly accepted indication. SCS is an
     accepted method for effective treatment of
     sympathetically mediated pain.

Question 91

722. Spinal cord stimulation
     (1) should be used early in the course of the
     postherpetic neuralgia pain syndrome
     (2) has been found efficacious for the failed
     back surgery syndrome
     (3) has been used for peripheral vascular
     disease and ischemic disease
     (4) has a proven and elucidated mechanism
     of action

Answer 91

722. (A) According to a review in 2008, SCS should
     be considered early in the course of postherpetic
     neuralgia and peripheral nerve stimulation
     should be considered if SCS fails. SCS is
     about 50% effective for failed back surgery syndrome
     and more so effective for peripheral vascular
     disease and ischemic disease. Although
     the gate control theory is a commonly cited
     mechanism of action for SCS, literature reflects
     that this one mechanism alone is not sufficient
     to explain the mechanism of action. According
     to a 2002 review article, there are 10 proposed
     mechanisms of action found in literature.
     [Oakley JC, Prager JP. Spinal cord stimulation:
     mechanisms of action. Spine. 2002; 27(22):
     2574-2583.]

Question 92

723. The transverse tripolar SCS arrangement
     (1) involves a central anode surrounded by
     cathodes
     (2) contributes maximum dorsal column
     stimulation with minimal dorsal root
     stimulation
     (3) is most frequently used to improve
     stimulation of the feet
     (4) usually involves an octapolar spinal
     midline lead and two adjacent
     quadripolar leads

Answer 92

723. (C) Transverse tripolar SCS on involves a central
     cathode surrounded by anodes. This is proposed
     to drive current deeper and thus
     stimulate fibers innervating the back. Therefore
     is it used to cover back pain, not foot pain.
     Statement (4) is also correct as most current
     SCS systems allow up to a total of 16 leads.

Question 93

724. Which of the following is (are) true for SCS for
     the indication of angina pectoris?
     (1) Improves exercise capacity
     (2) Probably only helps for a year and then
     the stimulator should be removed
     (3) In addition to providing antianginal
     effects it also provides a reduction in
     ischemia
     (4) Is contraindicated because it masks significant
     ischemic events

Answer 93

724. (B) In a 2006 review article SCS was concluded
     to increase exercise capacity as well as decrease
     use of short-acting nitrates and improve quality
     of life. The review also found that at 5 years
     60% of patients still had beneficial effects.
     Exercise stress testing and electrocardiogram
     (ECG) monitoring evidence showed reduced
     ischemia in addition to the antianginal effects.
     Pain perception remains intact and patients
     were still able to detect significant ischemic
     events. .]

Question 94

725. Which of the following is (are) the risk(s) associated
with SCS?
(1) Epidural hematoma
(2) Spinal cord injury
(3) Implanted pulse generator failure
(4) Electromechanical failure of lead or
extension cable

Answer 94

725. (E) All listed factors are risks of SCS. Other
     risks include nerve injury, dural puncture,
     infection, and electrode migration.

Question 95

726. Which of the following is (are) true regarding
     SCS for visceral pain?
     (1) SCS suppresses visceral response to
     colon distention in animal models
     (2) SCS is a first-line treatment for visceral
     pain
     (3) Case studies have indicated SCS may be
     helpful for visceral pain but at this time
     there is a lack of supporting randomized
     controlled trials
     (4) A good lead placement for stimulation
     of chronic pancreatitis would logically
     be around T12 or L1

Answer 95

726. (B) In animal models, SCS has been shown to
     suppress visceral responses. There have been
     multiple case reports of SCS being used successfully
     for visceral pain; however, current
     practice parameters do not address treatment
     of such pain. Since the pancreas is innervated
     by spinal segments around T5-T11, a lead
     placement would be much too low of a logical
     starting place. One case study reported placing
     the lead at T6 resulting in appropriate stimulation
     for treatment of chronic pancreatitis.

Question 96

727. Which of the following is (are) the best
     answer(s) regarding lead spacing and electrical fields created by a dual-lead stimulation system as pictured?
     (1) With larger distances between anodes
     and cathodes, the electric field tends to
     form a sphere
     (2) With tighter lead spacing and smaller
     distances between anodes and cathodes,
     the electric field is pulled towards the
     anode
     (3) Tight lead spacing increases the ratio of
     dorsal column to dorsal root stimulation
     (4) The anode is the positive contact and
     the cathode is the negative contact

Answer 96

727. (E) Anode is the correct designation for a positive
     contact and cathode is the correct designation
     for a negative contact. With a dual-lead
     system as pictured, the electric field would be
     pulled toward the anode if lead spacing were
     tight. With larger lead spacing, the electric field
     would tend to be more spherical and positioned
     around the cathode. Tight lead spacing
     increases the dorsal column to dorsal root stimulation
     ratio because the less spherical electric
     field would stimulate less laterally and therefore
     would have less stimulation in the areas of
     the nerve roots.

Question 97

728. Which of the following should be considered
when selecting patients for SCS?
(1) Disease pathology
(2) Untreated drug addiction
(3) Patient comorbidities
(4) Physician’s monthly case quota

Answer 97

728. (A) According to a review article on selection
     criteria for SCS, selection criteria may relate to
     the patient’s disease state or to other important
     patient characteristics. Current randomized
     controlled trials or prospective trials
     support efficacy of SCS for certain disease
     states such as failed back surgery syndrome,
     CRPS, axial back pain, postherpetic neuralgia,
     neuropathy, and pelvic pain. Current case
     report evidence exists for SCS in the treatment
     of ischemic limb pain, and visceral pain.
     Anginal pain has also been investigated.
     Patient characteristics of concern include systemic
     disease such as diabetes, immunocompromised,
     degree of stenosis especially for
     cervical placed leads, anticoagulation, psychologic
     comorbidities, unrealistic outcome expectations,
     and, untreated drug addictions.
     [Oakley JC. Spinal cord stimulation: patient
     selection, technique, and outcomes.

Question 98

729. Which of the following is (are) considered indication(
     s) for SCS?
     (1) Phantom limb pain
     (2) Spinal cord injury pain
     (3) Intractable abdominal or visceral pain
     (4) Neurogenic thoracic outlet syndrome

Answer 98

729. (E) The indications for SCS are expanding. All of the listed etiologies are now considered indications for SCS.

Question 99

730. Which of the following is (are) true regarding
     the history of electrical stimulation for the treatment
     of pain?
     (1) Electrical stimulation for the treatment
     of pain dates back to the first century ad
     when electrical fish were documented to
     be used in the treatment of gout
     (2) Implantable SCS were used for treatment
     of pain for a decade prior to the
     published gate control theory of pain
     (3) Early stimulation case reports were of
     peripheral nerve stimulation; later
     emphasis turned toward SCS
     (4) Psychiatric and/or psychologic screening
     evaluation prior to implants was a
     new idea imposed upon physicians by
     health maintenance organizations in the
     1990s

Answer 99

730. (B)
731. Scribonius Largus documented application
     of the live black torpedo fish under the foot
     for treatment of the pain of gout. “For any
     type of gout a live black torpedo should, when the
     pain begins, be placed under the feet. The patient
     must stand on a moist shore washed by the sea
     and he should stay like this until his whole foot
     and leg up to the knee is numb. This takes away
     present pain and prevents pain from coming on if
     it has not already arisen. In this way Anteros, a
     freedman of Tiberius, was cured.”
732. The gate control theory of pain was published
     in 1965. This laid the theoretical foundation
     for electrical stimulation for pain.
     The first modern case report of electrical
     stimulators for treatment of pain was 2 years
     later. It described eight cases in which sensory
     nerves or roots were stimulated resulting
     in relief of pain. [Melzack R, Wall PD.
     Mechanisms: a new theory. A gate control
     system modulates sensory input from the
     skin before it evokes pain perception and
     response. Science. 1965;150(3699).
     Wall PD, Sweet WH. Temporary abolition
     of pain in man. Science. 1967;155(758):108-109.]
733. In the peripheral nerves, motor and sensory
     fibers are within closer vicinity. The window of amplitude available to provide analgesia
     without excessive motor stimulation is
     therefore much less than in the spinal cord
     where sensory and motor fibers run in more
     discrete and separate pathways. This
     played a role in switching emphasis from
     peripheral nerve stimulation toward SCS.
734. The first documented cases of modern day
     stimulation for pain was a case series of eight
     patients published in 1967. This case series
     reported three of the eight patients received
     psychiatric evaluation prior to the procedures.
     The psychiatric/psychologic evaluation
     gives the patient an opportunity to belay
     anxiety, ask questions, address body image
     issues, and communicate expectations

Question 100

731. Which of the following is (are) accurate statement(
     s) regarding neuromodulation of the
     sacral nerves?
     (1) Sacral neuromodulation is not effective
     for idiopathic urinary frequency
     (2) Both percutaneous and surgical lead
     placement techniques have been
     described
     (3) Must be performed by a surgeon
     because only a surgical technique is
     available
     (4) Urgency and urge incontinence are
     indications

Answer 100

731. (C) Sacral neuromodulation has been reported
     as effective for idiopathic urinary frequency,
     urgency, and urge incontinence. Both percutaneous
     and surgical sacral neuromodulation
     procedures have been described. Percutaneous
     techniques include (1) placement of a lead
     directly into the sacral nerve root foramen and
     (2) a percutaneous retrograde approach.
     Surgical techniques include (1) performing a
     sacral laminectomy and attaching the electrodes
     directly to the sacral nerve roots and
     (2) dissection to sacral periosteum where a
     plastic anchor is used to affix a transforaminal
     lead. Techniques that are limited to one lead
     placement may have limitations in terms of
     efficacy for certain indications. While a single
     lead has been generally efficacious for voiding
     dysfunctions, chronic neuropathic pain syndromes
     may benefit from a more extensive field
     of neuromodulation with additional electrodes

Question 101

732. Which of the following is (are) true regarding
     radiofrequency procedures?
     (1) Pulsed radiofrequency lesioning temperature
     goal is generally around 42°C
     to 43°C
     (2) Prior to application of the radiofrequency
     lesion, sensory testing should be
     applied at 2 Hz
     (3) The standard pulsed radiofrequency
     lesion is 500,000 Hz for 20 milliseconds
     pulses once every 0.5 second for 90 to
     240 seconds
     (4) Prior to application of the radiofrequency
     lesion, motor testing should be
     applied at 50 Hz

Answer 101

732. (B)
733. Temperatures above 45°C cause irreversible
     neural tissue damage. If temperatures of
     45°C are reached, then the voltage should
     be decreased to compensate.
734. Sensory testing is applied at 50 Hz.
735. The pulsed technique allows tissues to
     cool somewhat between cycles. A voltage of 45 V generally corresponds to a 43°C
     tip temperature. If the tip temperature
     exceeds 43°C, then the voltage should be
     reduced.
736. Motor testing is applied at 2 Hz.

Question 102

733. Which of the following element(s) is (are) necessary
     to complete a radiofrequency circuit?
     (1) The radiofrequency generator
     (2) Insulated needle cannula with radiofrequency
     probe
     (3) Dispersive electrode (grounding pad)
     (4) The patient

Answer 102

733. (E) All the options mentioned in the question
     are required elements to complete the circuit.
     The current goes from the probe tip, through
     the patient and to the grounding pad which
     carries the current back to the radiofrequency
     generator.

Question 103

734. Which of the following is (are) the possible
mechanism(s) of action of radiofrequency
ablation?
(1) Vascular injury causing endoneural
edema
(2) Formation of a static electric field
(3) Lipid extraction with protein precipitation
(4) Generation of heat

Answer 103

734. (C) Formation of a static electric field and generation
     of heat are two phenonemon that have
     been postulated as possible mechanisms of
     action of radiofrequency ablation. The mechanism
     of action of cryoablation involves vascular
     injury which causes severe endoneural
     edema. The mechanism of action of alcohol
     ablative techniques is lipid extraction with protein
     precipitation.

Question 104

735. Which of the following is (are) the most accurate
     answer(s) regarding radiofrequency treatment
     of the SI joint?
     (1) Evidence is strong for efficacy of
     radiofrequency ablation techniques for
     SI joint pain
     (2) The universally accepted screening protocol
     prior to SI joint injection involves
     SI tenderness, positive SI provocative
     maneuvers, and two positive local anesthetic–
     only SI joint injection procedures
     (3) There is no evidence for the role of
     pulsed radiofrequency treatment of SI
     joint pain
     (4) Radiofrequency treatment of sacral lateral
     branches have been proposed for
     efficacious treatment of SI joint pain

Answer 104

735. (D)
736. Although there are several studies looking
     at radiofrequency neuroablation for the SI
     joint, according to a recent systematic
     review evidence is still limited for its therapeutic
     value.
737. Although there are guidelines such as those
     posed by International Association for the
     Study of Pain (IASP), evidence and universal
     acceptance are still lacking. Some studies
     have refuted SI provocative maneuvers
     as predictive at all while others found that
     three of five positive provocative maneuvers
     provide predictive value. The role of
     adding steroids to diagnostic SI injections is
     similarly debated.
738. Pulsed radiofrequency treatment was given
     to 22 patients with injection evidence of SI
     pain. Sixteen patients (73.9%) had 50% or
     better relief for more than 3 months.
739. In a 2003 pilot study, 8 of 9 patients experienced
     50% or better pain relief after
     radiofrequency lesioning at L4 primary
     dorsal rami and S1-S3 lateral branches.
     Relief persisted at 9 month follow-up.

Question 105

736. Purported advantages of percutaneous radiofrequency
     lesions over other neuroablative techniques
     include
     (1) predictable and quantifiable lesions
     (2) avoids the extensive soft tissue damage
     of surgical techniques
     (3) ability to confirm needle-tip proximity
     to sensory and motor nerves
     (4) ability to cover a wide field

Answer 105

736. (A) Other advantages of radiofrequency lesions
     include avoids sticking and charring (in contrast
     to direct current electrical lesions), no gas formation
     (in contrast to direct current electrical
     lesions), impedance monitoring, and amenable
     to fluoroscopic and CT guidance. Ability to identify
     needle-tip proximity to motor and sensory
     nerves is a characteristic of radiofrequency procedures,
     although cryoanalgesia probes are also
     available with built-in nerve stimulators. Ability
     to cover a wide field is not an advantage of percutaneous
     radiofrequency lesion. Percutaneous
     radiofrequency techniques deliver relatively
     smaller, more defined treatment areas and therefore
     a great deal of lesions would be needed in
     order to cover a wide field target.

Question 106

737. Which of the following is (are) accurate regarding
     the history of ablation techniques?
     (1) Norman Shealy reported the first use of
     radiofrequency lesioning for treatment
     of facet pain in 1975
     (2) The first report of percutaneous
     radiofrequency lesioning for treatment
     of pain came in 1981
     (3) Slappendel reported the first clinical use
     of pulsed radiofrequency lesioning in
     1997
     (4) Although a modern cryoneuroablation
     device was developed and refined in the
     1960s, the application for pain management
     gained popularity in the 1980s

Answer 106

737. (E) These are all accurate historical events as
     described and cited in current literature
     reviews. Pulsed radiofrequency techniques
     have received growing interest since 1997,
     when treatment of the cervical spinal dorsal
     root ganglions with pulsed radiofrequency
     suggested efficacy and safety. In 1961, Cooper
     described a device which used liquid nitrogen
     in a hollow tube that was insulated at the tip
     and achieved temperatures as low as −190°C.
     He published his description in a hospital bulletin.
     Six years later an ophthalmic surgeon by
     the name of Amoils improved on the device.
     Lloyd coined the term “cryoanalgesia” in 1976.
     The technique was popularized in the 1980s,
     but publications have declined since. [Cooper
     IS, Lee AS. Cryostatic congelation: a system for
     producing a limited, controlled region of cooling
     or freezing of biologic tissues.

Question 107

738. Which of the following is (are) accurate regarding
     lesion size?
     (1) The size of a continuous radiofrequency
     lesion depends on temperature induced
     (2) The size of a continuous radiofrequency
     lesion depends on the width of the needle
     (3) A 2 mm cryoanalgesia probe forms an
     ice ball about 5.5 mm thick
     (4) A 1.4 mm cryoanalgesia probe forms an
     ice ball about 3.5 mm thick

Answer 107

738. (E) The size of a continuous radiofrequency
     lesion depends on temperature, width of
     needle, and length of exposed (uninsulated)
     cannula. The 1.4-mm cryoanalgesia probe
     forms an ice ball about 3.5 mm thick, while the larger 2-mm probe forms and ice ball about 5.5 mm thick. Thus the ice ball is about 2.5 to 2.75 times larger than the probe for these size probes.

Question 108

739. Which of the following is (are) components of
     a cryoanalgesia system?
     (1) Outer tube with smaller inner tube
     (2) Pressurized gas in inner tube
     (3) Fine aperture in tip of inner tube which
     allows gas to rapidly expand in tip of
     outer tube
     (4) Fine aperture in tip of outer tube which
     allows gas to escape the tube system

Answer 108

739. (A) Acryoprobe is comprised of a tube within
     a tube. The inner tube is pressurized with a
     gas such as nitrous oxide or carbon dioxide at
     600 to 800 psi. As the gas escapes through a
     narrow aperture at the tip of the inner tube, it
     (the gas) abruptly expands in the larger outer
     tube at a lower pressure of about 10 to 15 psi.
     As the gas expands, it (the gas) cools. This is
     known as the Joule-Thompson effect. An ice
     ball then forms at the tip of the probe. The gas
     does not escape out through a fine aperture in
     the tip of the outer tube. This would allow the
     gas to enter the patient’s tissues. Instead, gas
     escapes back up the larger outer tube in a
     closed system design

Question 109

740. Which of the following is (are) potential neuroablative
     procedure treatment options?
     (1) Radiofrequency ablation of the L2
     ramus communicans for treatment of
     L4-L5 discogenic pain
     (2) Phenol neurolysis for treatment of the
     lumbar sympathetic plexus for treatment
     of CRPS of the lower extremity
     (3) Radiofrequency ablation for treatment
     of the lumbar sympathetic plexus for
     treatment of CRPS of the lower
     extremity
     (4) Cryoablation for the treatment of pain
     owing to superior gluteal nerve
     entrapment

Answer 109

740. (E)
741. It has been postulated that the sinuvertebral
     nerves at each lumbar level transmit
     sensory information from the intervertebral
     discs to the paravertebral chain on each
     side. The rami communicans then communicate
     this sensory information to the dorsal
     root ganglia at L1 and L2.
742. and 3. Both radiofrequency and phenol
     lumbar sympathetic neurolytic techniques
     have been described for the treatment of
     lower extremity CRPS.
743. Cryoablation has been utilized for pain of
     the superior gluteal nerve. (Trescot, Pain
     Physician, 2003, v. 6, p. 345-360, Cryoanalgesia
     in interventional pain management)

Question 110

741. Which of the following is (are) potential advantage(
     s) of pulsed radiofrequency procedure
     over continuous radiofrequency ablation?
     (1) Pulsed radiofrequency procedure is virtually
     painless as compared to continuous
     radiofrequency ablation during
     which patients often complain of pain
     (2) Overwhelming evidence of greater efficacy
     with pulsed radiofrequency procedure
     over continuous radiofrequency
     ablation
     (3) As compared to pulsed radiofrequency
     ablation, continuous radiofrequency
     ablation of lumbar medial branches carries
     a higher risk of inducing spinal
     instability secondary to multifidus
     muscle denervation
     (4) Complications caused by needle injury
     of tissues is less with pulsed radiofrequency
     procedure compared to continuous
     radiofrequency ablation

Answer 110

741. (B)
742. Pulsed radiofrequency procedure is virtually
     painless. Continuous radiofrequency
     ablation is painful with application.
743. There is debate in literature as to whether
     pulsed radiofrequency procedure is as efficacious
     as radiofrequency ablation.
744. In addition to innervating the zygapophysial
     joint, the medial branch of the dorsal ramus
     also innervates the multifidus, interspinales, and intertransversarii mediales muscles, the
     interspinous ligament, and, possibly, the ligamentum
     flavum.
745. In both cases a cannula and radiofrequency
     probe of similar size are inserted.

Question 111

742. Which of the following is (are) correct regarding
     impedance measurement during radiofrequency
     procedures?
     (1) While performing a radiofrequency procedure,
     the lower the impedance value
     the better the expected outcome
     (2) Impedance measurement can detect
     needle-tip entry into different mediums
     such as vascular structures or periosteum
     (3) Impedance values are neither customary
     nor necessary when using fluoroscopic
     guidance
     (4) Impedance measurement can detect
     breaks or short circuits in the electrical
     circuit

Answer 111

742. (C)
743. Too low an impedance may indicate the
     needle tip is in nontarget tissues such as
     vasculature, CSF, or nucleus pulposus.
744. This statement is correct.
745. It is traditional to use impedance information
     in assisting needle-tip placement even
     during fluoroscopically guided procedures.
746. This statement is correct. Superior gluteal
     nerve entrapment is amenable to cryoablation.