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ABPS Interventional Pain Management study materials
ABPS Interventional Pain Management study resources

ABPS Interventional Pain Management practice questions

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Question 1Patient Evaluation and Diagnosis

A patient reports burning pain in the distribution of the lateral femoral cutaneous nerve with no motor weakness. Which finding best supports a diagnosis of meralgia paresthetica?

  1. Weakness of hip flexion and knee extension
  2. Absent patellar reflex on the affected side
  3. Reproduction of symptoms with hip extension and external rotation
  4. Sensory loss over the anterior thigh that spares the medial thigh Correct answer.

Explanation

Meralgia paresthetica is an entrapment of the lateral femoral cutaneous nerve, a purely sensory nerve, so findings are limited to numbness or burning over the anterolateral thigh with sparing of the medial thigh and no motor or reflex changes. Motor weakness and reflex loss imply involvement of the femoral nerve or lumbosacral plexus.

Question 2Patient Evaluation and Diagnosis

Which clinical feature most reliably distinguishes neuropathic from nociceptive pain on history alone?

  1. Pain that is worse with movement
  2. Pain that awakens the patient at night
  3. Pain that improves with rest
  4. Pain described as burning, shooting, or electric with accompanying dysesthesia Correct answer.

Explanation

Neuropathic pain is characterized by descriptors such as burning, lancinating, or electric shock-like quality, often with dysesthesia or allodynia, reflecting somatosensory lesion or disease. Mechanical worsening, nocturnal awakening, and rest relief are nonspecific and occur in both nociceptive and neuropathic states.

Question 3Patient Evaluation and Diagnosis

A patient with suspected lumbar spinal stenosis is being evaluated. Which historical feature is most characteristic?

  1. Night pain relieved by aspirin
  2. Pain worsened by sitting and relieved by walking
  3. Neurogenic claudication relieved by forward flexion and sitting Correct answer.
  4. Unilateral radicular pain worsened by coughing

Explanation

Lumbar spinal stenosis classically produces neurogenic claudication with bilateral leg symptoms provoked by standing or walking and relieved by sitting or leaning forward, which increases canal dimensions. Radicular pain worsened by Valsalva suggests disc herniation or foraminal stenosis rather than central canal stenosis.

Question 4Patient Evaluation and Diagnosis

During a physical examination, a patient's pain in the buttock is reproduced when the hip is flexed, adducted, and internally rotated. Which structure is being tested?

  1. Piriformis muscle
  2. Lumbar facet joint
  3. Sacroiliac joint
  4. Hip joint (FABER versus FADIR distinction) Correct answer.

Explanation

The FADIR (flexion, adduction, internal rotation) maneuver is an impingement test for the hip joint and reproduces pain in intra-articular hip pathology. The FABER test, by contrast, stresses the sacroiliac joint and hip.

Question 5Patient Evaluation and Diagnosis

Which imaging modality is the preferred initial study for a patient with suspected acute lumbar disc herniation and progressive motor deficit?

  1. Plain radiography
  2. Magnetic resonance imaging without contrast Correct answer.
  3. Bone scan
  4. Computed tomography without contrast

Explanation

MRI without contrast is the study of choice for evaluating suspected disc herniation with neurologic deficit because it best demonstrates soft tissue, nerve roots, and the spinal canal. Plain films and CT show bone well but poorly characterize discs and neural compression.

Question 6Patient Evaluation and Diagnosis

A patient describes pain radiating down the posterior thigh to the lateral calf and dorsum of the foot, with weakness of great toe extension. Which nerve root is most likely involved?

  1. S2
  2. S1
  3. L4
  4. L5 Correct answer.

Explanation

The L5 root supplies great toe extension via the extensor hallucis longus and its dermatome covers the lateral calf and dorsum of the foot. S1 radiculopathy instead affects plantar flexion and the lateral foot and sole.

Question 7Patient Evaluation and Diagnosis

Which finding on sensory examination is most consistent with a small-fiber neuropathy?

  1. Positive Romberg sign
  2. Absent ankle reflexes with preserved pinprick
  3. Reduced pinprick and temperature sensation with preserved proprioception Correct answer.
  4. Reduced vibration sense at the toes

Explanation

Small-fiber neuropathy affects thinly myelinated and unmyelinated fibers carrying pain and temperature, so pinprick and temperature are impaired while large-fiber modalities such as vibration and proprioception remain intact. Vibration loss, Romberg sign, and reflex loss reflect large-fiber disease.

Question 8Patient Evaluation and Diagnosis

A patient with chronic low back pain reports pain out of proportion to examination findings and demonstrates widespread nonanatomic tenderness. Which screening instrument is most appropriate to assess for centralized or biopsychosocial contributors?

  1. Pain Catastrophizing Scale Correct answer.
  2. Oswestry Disability Index
  3. Dermatomal sensory mapping
  4. Visual analog scale

Explanation

The Pain Catastrophizing Scale quantifies catastrophic thinking, a psychosocial factor that amplifies pain and predicts poorer outcomes, making it suitable for evaluating centralized or biopsychosocial contributors. The Oswestry index measures disability rather than psychologic contributors, and the VAS measures intensity only.

Question 9Patient Evaluation and Diagnosis

Which historical element is most important to obtain before proceeding with interventional pain procedures in a patient on anticoagulation?

  1. Timing of last dose and renal function Correct answer.
  2. Dietary habits
  3. Family history of cardiovascular disease
  4. Prior response to physical therapy

Explanation

Periprocedural bleeding risk depends on the specific agent, the interval since the last dose, and clearance, which is influenced by renal function for many direct oral anticoagulants. This information guides whether to delay, bridge, or reschedule the procedure.

Question 10Patient Evaluation and Diagnosis

A patient presents with acute herpes zoster in the T6 dermatome. Which statement about postherpetic neuralgia risk is most accurate?

  1. Risk is highest in patients under 30 years of age
  2. Advanced age and severe acute pain increase the risk Correct answer.
  3. Risk is unrelated to the severity of the acute rash
  4. Antiviral therapy has no effect on subsequent pain

Explanation

Advanced age and severe acute zoster pain are the strongest established predictors of postherpetic neuralgia. Early antiviral therapy reduces both acute severity and the likelihood of persistent pain.

Question 11Patient Evaluation and Diagnosis

Which finding on examination best supports a diagnosis of complex regional pain syndrome of the upper extremity?

  1. Bilateral symmetric weakness
  2. Dermatomal sensory loss confined to a single nerve root
  3. Isolated loss of vibration sense
  4. Disproportionate pain with vasomotor, sudomotor, or trophic changes Correct answer.

Explanation

Complex regional pain syndrome is diagnosed clinically by disproportionate pain plus at least one symptom in two or more categories, including sensory, vasomotor, sudomotor, and motor/trophic changes. Findings that follow a single dermatome or are symmetric suggest alternative diagnoses.

Question 12Patient Evaluation and Diagnosis

A patient reports unilateral occipital headache with tenderness over the greater occipital nerve and reduced sensation in its distribution. Which diagnosis is most likely?

  1. Occipital neuralgia Correct answer.
  2. Trigeminal neuralgia of the third division
  3. Cervical facet arthropathy at C2-C3
  4. Temporomandibular disorder

Explanation

Occipital neuralgia produces paroxysmal or constant pain in the greater, lesser, or third occipital nerve distribution with tenderness over the nerve and often sensory change, typically responding to local anesthetic blockade. Trigeminal third-division pain involves the jaw and chin, not the occiput.

Question 13Patient Evaluation and Diagnosis

Which physical examination test is used to assess for thoracic outlet syndrome by eliciting a radial pulse change with shoulder positioning?

  1. Phalen test
  2. Adson maneuver Correct answer.
  3. Spurling test
  4. Tinel sign at the wrist

Explanation

The Adson maneuver rotates and extends the shoulder with the head turned toward the affected side while monitoring the radial pulse, and pulse obliteration with symptom reproduction suggests thoracic outlet syndrome. Phalen and Tinel tests assess the carpal tunnel, and Spurling tests the cervical root.

Question 14Patient Evaluation and Diagnosis

A patient with suspected sacroiliac joint pain is examined. Which combination of history and examination findings is most consistent with this diagnosis?

  1. Pain with lumbar extension and rotation only
  2. Pain reproduced by hip internal rotation
  3. Pain above L4 with positive straight leg raise at 30 degrees
  4. Pain below L5 with tenderness over the sacral sulcus and positive provocation tests Correct answer.

Explanation

Sacroiliac joint pain is typically perceived below the L5 level, with tenderness over the sacral sulcus and reproduction by provocation tests such as distraction, compression, and thigh thrust. Radicular pain provoked by straight leg raise or hip internal rotation points elsewhere.

Question 15Patient Evaluation and Diagnosis

Which of the following best describes the diagnostic role of a medial branch block in suspected lumbar facet-mediated pain?

  1. It is a definitive treatment that predicts long-term relief
  2. It confirms the diagnosis of discogenic pain
  3. It is a prognostic test whose relief response supports proceeding to radiofrequency ablation Correct answer.
  4. It assesses nerve root compression

Explanation

Medial branch blocks are used as a prognostic step to identify patients whose facet-mediated pain is likely to respond to radiofrequency denervation, and concordant relief on controlled blocks supports that decision. They do not diagnose discogenic pain or assess root compression.

Question 16Patient Evaluation and Diagnosis

A patient reports lancinating facial pain triggered by chewing and touch in the mandibular region. Which diagnosis is most consistent with this presentation?

  1. Temporal arteritis
  2. Glossopharyngeal neuralgia
  3. Trigeminal neuralgia Correct answer.
  4. Atypical odontalgia

Explanation

Trigeminal neuralgia causes brief, electric shock-like pain in a trigeminal division distribution triggered by light touch, chewing, or talking. Glossopharyngeal neuralgia involves the throat and tonsillar region, and temporal arteritis produces a constant ache with systemic features.

Question 17Patient Evaluation and Diagnosis

Which historical feature best distinguishes radicular from referred somatic lumbar pain?

  1. Pain confined to the midline
  2. Pain that resolves with heat application
  3. Pain that is always bilateral
  4. Pain that follows a dermatomal distribution and may be accompanied by paresthesia Correct answer.

Explanation

Radicular pain follows a specific nerve root dermatome, is often described as sharp or electric, and may be accompanied by paresthesia or weakness in that distribution. Referred somatic pain is typically aching, poorly localized, and does not follow a dermatome.

Question 18Patient Evaluation and Diagnosis

A patient with suspected cervical myelopathy is examined. Which finding most strongly supports this diagnosis?

  1. Unilateral dermatomal numbness
  2. Reduced grip strength alone
  3. Hyperreflexia with a positive Hoffmann sign Correct answer.
  4. Positive Spurling test

Explanation

Cervical myelopathy produces upper motor neuron signs such as hyperreflexia, a Hoffmann sign, and gait disturbance due to cord compression. Spurling and dermatomal findings reflect root-level disease rather than cord involvement.

Question 19Patient Evaluation and Diagnosis

Which element of the history is most important when evaluating a patient with new thoracic spine pain before considering interventional treatment?

  1. Occupational lifting history
  2. Family history of osteoarthritis
  3. Dietary calcium intake
  4. Presence of red flags such as fever, weight loss, or cancer history Correct answer.

Explanation

Thoracic pain can be the presenting feature of serious pathology such as malignancy, infection, or fracture, so red flags must be screened before any intervention. Absent red flags, mechanical causes become more likely.

Question 20Patient Evaluation and Diagnosis

A patient with suspected piriformis syndrome is examined. Which finding best supports the diagnosis?

  1. Sensory loss over the medial foot
  2. Absent Achilles reflex
  3. Pain reproduced by resisted hip abduction and external rotation in the seated position Correct answer.
  4. Positive straight leg raise at 70 degrees

Explanation

Piriformis syndrome is suggested by reproduction of deep gluteal pain with resisted abduction and external rotation, which loads the piriformis, often with tenderness over the muscle. Radicular findings such as reflex loss or dermatomal sensory change point to a nerve root source.

Question 21Pharmacology and Medical Management of Pain

Which oral medication is a first-line adjuvant for neuropathic pain and requires monitoring of renal function because it is renally cleared?

  1. Ibuprofen
  2. Amitriptyline
  3. Morphine
  4. Gabapentin Correct answer.

Explanation

Gabapentinoids are first-line adjuvants for neuropathic pain, and gabapentin is eliminated unchanged by the kidney, so doses must be adjusted in renal impairment. NSAIDs and opioids are not first-line neuropathic agents, and amitriptyline is hepatically metabolized.

Question 22Pharmacology and Medical Management of Pain

A patient on chronic opioid therapy presents with pinpoint pupils, respiratory depression, and decreased consciousness. Which agent is the appropriate reversal?

  1. Naloxone Correct answer.
  2. Flumazenil
  3. Atropine
  4. N-acetylcysteine

Explanation

The triad of miosis, respiratory depression, and depressed consciousness indicates opioid toxicity, and naloxone is a competitive opioid receptor antagonist that reverses it. Flumazenil reverses benzodiazepines, atropine is anticholinergic, and N-acetylcysteine treats acetaminophen toxicity.

Question 23Pharmacology and Medical Management of Pain

Which medication is classified as an NSAID with predominantly COX-2 selectivity at therapeutic doses?

  1. Celecoxib Correct answer.
  2. Ketorolac
  3. Acetaminophen
  4. Indomethacin

Explanation

Celecoxib is a selective COX-2 inhibitor, which reduces gastrointestinal ulcer risk relative to nonselective NSAIDs. Ketorolac and indomethacin are nonselective NSAIDs, and acetaminophen is an analgesic/antipyretic with minimal anti-inflammatory action.

Question 24Pharmacology and Medical Management of Pain

Which laboratory parameter should be monitored during long-term NSAID therapy because of the risk of gastrointestinal and renal effects?

  1. Serum calcium
  2. Serum amylase
  3. Serum creatinine Correct answer.
  4. Prothrombin time

Explanation

NSAIDs can reduce renal prostaglandin synthesis and impair renal perfusion, so serum creatinine (and renal function) should be monitored. Amylase, prothrombin time, and calcium are not the standard monitoring parameters for NSAID toxicity.

Question 25Pharmacology and Medical Management of Pain

Which agent is a serotonin-norepinephrine reuptake inhibitor commonly used for painful diabetic peripheral neuropathy?

  1. Ondansetron
  2. Duloxetine Correct answer.
  3. Lorazepam
  4. Metoprolol

Explanation

Duloxetine is an SNRI with established efficacy for painful diabetic peripheral neuropathy and fibromyalgia. Ondansetron is a 5-HT3 antagonist antiemetic, metoprolol is a beta-blocker, and lorazepam is a benzodiazepine.

Question 26Pharmacology and Medical Management of Pain

Which opioid is a partial mu-receptor agonist and antagonist at the kappa receptor, making it useful for opioid rotation in some patients?

  1. Fentanyl
  2. Hydromorphone
  3. Oxycodone
  4. Buprenorphine Correct answer.

Explanation

Buprenorphine is a partial mu agonist with high receptor affinity and kappa antagonism, giving it a ceiling effect on respiratory depression and utility in rotation. Fentanyl, hydromorphone, and oxycodone are full mu agonists.

Question 27Pharmacology and Medical Management of Pain

A patient on warfarin is started on an NSAID for musculoskeletal pain. Which interaction is the most important concern?

  1. Enhanced warfarin metabolism causing subtherapeutic INR
  2. Reduced warfarin absorption from altered gastric pH
  3. Increased bleeding risk from platelet inhibition and protein-binding displacement Correct answer.
  4. Increased renal clearance of warfarin

Explanation

NSAIDs inhibit platelet cyclooxygenase and can displace warfarin from albumin, both of which increase bleeding risk, and NSAIDs also cause GI mucosal injury. They do not reduce absorption, induce warfarin metabolism, or increase its renal clearance.

Question 28Pharmacology and Medical Management of Pain

Which property best explains why transdermal fentanyl reaches steady-state slowly and has a delayed onset after patch application?

  1. High plasma protein binding that blocks diffusion
  2. Immediate renal tubular secretion
  3. A depot in skin and subcutaneous tissue that slowly releases drug Correct answer.
  4. Rapid hepatic first-pass metabolism

Explanation

Transdermal fentanyl forms a subcutaneous depot, so absorption is gradual and steady-state is reached over many hours to days, with delayed onset and offset. First-pass metabolism is bypassed by transdermal delivery, and renal secretion does not explain the slow onset.

Question 29Pharmacology and Medical Management of Pain

Which medication is the preferred first-line treatment for trigeminal neuralgia?

  1. Prednisone
  2. Carbamazepine Correct answer.
  3. Baclofen
  4. Sumatriptan

Explanation

Carbamazepine is the first-line agent for trigeminal neuralgia, with oxcarbazepine as an alternative. Sumatriptan treats migraine, prednisone is not first-line, and baclofen is a second-line or adjunctive option.

Question 30Pharmacology and Medical Management of Pain

A patient develops myoclonus, hyperreflexia, and agitation after starting tramadol while also taking an SSRI. Which syndrome is most likely?

  1. Malignant hyperthermia
  2. Anticholinergic toxicity
  3. Neuroleptic malignant syndrome
  4. Serotonin syndrome Correct answer.

Explanation

Tramadol inhibits serotonin reuptake, and combining it with an SSRI can precipitate serotonin syndrome, marked by neuromuscular hyperactivity, autonomic instability, and altered mental status. Neuroleptic malignant syndrome and malignant hyperthermia present differently, and anticholinergic toxicity causes dry skin and flushing rather than hyperreflexia.

Question 31Pharmacology and Medical Management of Pain

Which agent is a topical local anesthetic commonly used as a 5% patch for postherpetic neuralgia?

  1. Diclofenac
  2. Ketamine
  3. Lidocaine Correct answer.
  4. Capsaicin

Explanation

A 5% lidocaine patch is approved for postherpetic neuralgia and provides local analgesia by blocking sodium channels. Capsaicin is a TRPV1 agonist, diclofenac is a topical NSAID, and ketamine is an NMDA antagonist.

Question 32Pharmacology and Medical Management of Pain

Which analgesic is most appropriate for a patient with severe chronic kidney disease who needs a non-opioid adjuvant for neuropathic pain, given the need to avoid renally cleared drugs?

  1. Amitriptyline
  2. Ketorolac
  3. Duloxetine Correct answer.
  4. Pregabalin at reduced dose

Explanation

Duloxetine is hepatically metabolized and does not require renal dose adjustment, making it a reasonable choice in severe renal impairment, whereas pregabalin is renally cleared and requires dose reduction. Amitriptyline is an alternative but has anticholinergic and cardiac concerns, and ketorolac is contraindicated in renal impairment.

Question 33Pharmacology and Medical Management of Pain

Which opioid metabolite accumulates in renal failure and can cause prolonged sedation and respiratory depression?

  1. Naloxone
  2. Codeine
  3. Morphine-6-glucuronide Correct answer.
  4. Morphine-3-glucuronide

Explanation

Morphine-6-glucuronide is an active metabolite that is renally excreted and accumulates in renal failure, producing prolonged analgesia and respiratory depression. Morphine-3-glucuronide is inactive/neuroexcitatory, naloxone is an antagonist, and codeine is a prodrug.

Question 34Pharmacology and Medical Management of Pain

A patient on long-term high-dose morphine develops hyperalgesia, myoclonus, and sedation. Which mechanism best explains these findings?

  1. Opioid-induced hyperalgesia and neuroexcitation from metabolite accumulation Correct answer.
  2. Local anesthetic systemic toxicity
  3. Acute opioid withdrawal
  4. Serotonin syndrome from morphine

Explanation

High-dose chronic opioid therapy can produce opioid-induced hyperalgesia and neuroexcitation (myoclonus) related to active metabolite accumulation. These features are not explained by serotonin syndrome, withdrawal, or local anesthetic toxicity.

Question 35Pharmacology and Medical Management of Pain

Which medication is an NMDA receptor antagonist used as an adjunct for refractory neuropathic pain and for opioid tolerance?

  1. Ketamine Correct answer.
  2. Memantine
  3. Topiramate
  4. Lamotrigine

Explanation

Ketamine is an NMDA receptor antagonist used at subanesthetic doses for refractory neuropathic pain and to reduce opioid tolerance. Memantine is also an NMDA antagonist but is used for dementia, topiramate is an antiepileptic, and lamotrigine is a sodium-channel blocker.

Question 36Pharmacology and Medical Management of Pain

A patient with cancer pain has been on oral morphine with inadequate analgesia and intolerable side effects. Which principle best guides opioid rotation?

  1. Double the current opioid dose without conversion
  2. Switch to a different opioid using equianalgesic conversion and reduce for incomplete cross-tolerance Correct answer.
  3. Discontinue opioids abruptly and start an NSAID
  4. Add a second full mu agonist at the same dose

Explanation

Opioid rotation uses equianalgesic dose tables and then typically reduces the calculated dose by 25-50% to account for incomplete cross-tolerance, improving the balance of analgesia and side effects. Doubling without conversion risks overdose, adding a second full agonist increases toxicity, and abrupt discontinuation risks withdrawal and uncontrolled pain.

Question 37Pharmacology and Medical Management of Pain

Which pharmacokinetic feature distinguishes methadone from most other opioids and necessitates careful titration?

  1. Complete renal excretion unchanged
  2. No hepatic metabolism
  3. Very short elimination half-life
  4. Variable half-life with accumulation over days Correct answer.

Explanation

Methadone has a long and variable elimination half-life that far exceeds its analgesic duration, so repeated dosing leads to accumulation over days and requires cautious titration. It is hepatically metabolized, not renally excreted unchanged, and its half-life is long rather than short.

Question 38Pharmacology and Medical Management of Pain

A patient on a MAO inhibitor requires treatment for severe pain. Which analgesic should be avoided because of the risk of hypertensive crisis and serotonergic reactions?

  1. Meperidine Correct answer.
  2. Ibuprofen
  3. Gabapentin
  4. Acetaminophen

Explanation

Meperidine (and other serotonergic opioids such as tramadol) should be avoided with MAO inhibitors because of the risk of hypertensive crisis and serotonin syndrome. Acetaminophen, ibuprofen, and gabapentin do not carry this specific interaction.

Question 39Pharmacology and Medical Management of Pain

Which statement best explains why codeine analgesia is unreliable across populations?

  1. Codeine acts primarily at kappa receptors
  2. Codeine is an active drug excreted unchanged
  3. Codeine is a prodrug requiring CYP2D6 conversion to morphine Correct answer.
  4. Codeine is metabolized by CYP3A4 to an inactive compound only

Explanation

Codeine is a prodrug that requires CYP2D6-mediated O-demethylation to morphine for analgesia, so poor metabolizers get little effect and ultrarapid metabolizers risk toxicity. It is not excreted unchanged as the active form, is not solely inactivated by CYP3A4, and does not act primarily at kappa receptors.

Question 40Pharmacology and Medical Management of Pain

A patient with chronic pain on a stable opioid regimen reports new-onset constipation. Which agent is preferred for opioid-induced constipation that has not responded to laxatives?

  1. Naloxone orally at high dose
  2. Loperamide
  3. Ondansetron
  4. Methylnaltrexone Correct answer.

Explanation

Peripherally acting mu-opioid receptor antagonists such as methylnaltrexone treat opioid-induced constipation without reversing central analgesia. High-dose oral naloxone can cause systemic withdrawal, loperamide is an antidiarrheal, and ondansetron is an antiemetic.

Question 41Interventional Diagnostic Procedures

On a fluoroscopically guided transforaminal epidural steroid injection at L4, the needle tip is advanced toward which bony target?

  1. The pedicle of L4 Correct answer.
  2. The L4-L5 interlaminar space
  3. The center of the L4 vertebral body
  4. The superior articular process of L5

Explanation

Transforaminal access follows the 'safe triangle' whose superior border is the pedicle of the segmental nerve being targeted; the needle is walked just inferior to the pedicle in the AP view. The interlaminar space is used for interlaminar, not transforaminal, access.

Question 42Interventional Diagnostic Procedures

Which view best confirms that a lumbar medial branch block needle is at the junction of the superior articular process and transverse process?

  1. Lateral view
  2. Anteroposterior view Correct answer.
  3. Open-mouth odontoid view
  4. Oblique view

Explanation

In the AP projection the medial branch lies at the 'silhouette' where the superior articular process meets the transverse process, at the base of the SAP. The lateral view is used to judge depth and confirm the needle does not pass ventral to the neural foramen.

Question 43Interventional Diagnostic Procedures

During a diagnostic lumbar facet joint injection, correct intra-articular placement is best confirmed by which finding?

  1. Aspiration of synovial fluid
  2. Loss of resistance to saline
  3. Contrast outlining the joint capsule without intravascular or epidural spread Correct answer.
  4. Concordant pain provocation

Explanation

Contrast arthrography demonstrating the joint capsule contour without vascular or epidural runoff confirms intra-articular needle position. Loss of resistance and pain provocation are supportive but not definitive for intra-articular placement.

Question 44Interventional Diagnostic Procedures

A diagnostic selective nerve root block is intended primarily to answer which question?

  1. Whether the disc is degenerated
  2. Whether the patient has a systemic neuropathy
  3. Whether the patient has central canal stenosis
  4. Whether a specific nerve root is the source of pain Correct answer.

Explanation

A selective nerve root block places local anesthetic at a single nerve root to determine whether that root is generating the patient's pain. Imaging findings such as stenosis or disc degeneration are anatomic and not equivalent to the clinical pain generator.

Question 45Interventional Diagnostic Procedures

Which structure is most at risk during a C7 transforaminal epidural steroid injection performed via the posterior approach if the needle is advanced too far anteriorly?

  1. Phrenic nerve
  2. Vertebral artery Correct answer.
  3. Recurrent laryngeal nerve
  4. Spinal cord

Explanation

At the cervical level the vertebral artery lies in the foramen transversarium near the anterolateral aspect of the intervertebral foramen; anterior needle migration risks arterial puncture and catastrophic infarction. The spinal cord is at risk with medial or deep overadvancement but the classic anterior structure is the vertebral artery.

Question 46Interventional Diagnostic Procedures

In a diagnostic provocation discography, a disc is generally considered positive when which combination is present?

  1. High-pressure injection with dissimilar pain
  2. Concordant pain at low pressure with a morphologically abnormal disc and a control disc that is nonpainful Correct answer.
  3. Low-pressure injection with no pain
  4. Any pain reproduced at maximum pressure regardless of control levels

Explanation

A positive discogram requires reproduction of the patient's typical pain at low pressure in an abnormal disc, with at least one control level not reproducing pain. Pressure thresholds and concordance distinguish a symptomatic disc from a normal or nonpainful degenerated disc.

Question 47Interventional Diagnostic Procedures

Which finding on a diagnostic sacroiliac joint injection most strongly supports the joint as the pain source?

  1. Immediate reproduction of pain during injection
  2. Post-procedure soreness at the injection site
  3. Temporary reduction of the patient's typical pain after intra-articular local anesthetic Correct answer.
  4. Fluoroscopic confirmation of contrast within the joint

Explanation

The diagnostic value of an SI joint block lies in whether the patient's usual pain is substantially relieved after local anesthetic placed intra-articularly. Contrast confirmation establishes placement but not that the joint generates the pain.

Question 48Interventional Diagnostic Procedures

A patient reports 80% relief lasting 45 minutes after a diagnostic medial branch block with bupivacaine. How should this result be interpreted?

  1. Negative because relief did not last several days
  2. Positive because relief exceeded 50% and lasted beyond the expected anesthetic duration Correct answer.
  3. Equivocal because bupivacaine is too short-acting
  4. Invalid because provocation was not performed

Explanation

A positive response generally requires substantial relief exceeding roughly 50% that outlasts the expected duration of the local anesthetic used, indicating a true diagnostic effect. Relief lasting only as long as the anesthetic itself is less convincing.

Question 49Interventional Diagnostic Procedures

Which parameter is most important to document when performing comparative diagnostic local anesthetic blocks?

  1. The volume and concentration of local anesthetic used Correct answer.
  2. The gauge of the introducer needle
  3. The patient's blood pressure trend
  4. The duration of fluoroscopy time

Explanation

Comparative blocks rely on using a short-acting and a long-acting anesthetic at defined volumes and concentrations so that duration of relief can be compared against expected drug kinetics. Standardizing dose is essential for valid interpretation.

Question 50Interventional Diagnostic Procedures

During an interlaminar lumbar epidural injection, loss of resistance to air or saline indicates which finding?

  1. Entry into a paraspinal muscle
  2. Entry into the epidural space Correct answer.
  3. Entry into the ligamentum flavum
  4. Entry into the subarachnoid space

Explanation

Loss of resistance occurs when the needle tip passes through the ligamentum flavum and enters the lower-resistance epidural space. Further advancement risks dural puncture and subarachnoid placement.