Chapter 06 Pain Management

Question 1

Nociceptor

A receptor preferentially sensitive to a _________ stimulus or to a stimulus that would become _________ if prolonged.

Answer 1

Nociceptor

A receptor preferentially sensitive to a noxious stimulus or to a stimulus that would become noxious if prolonged.

Question 2

Allodynia

Pain due to a stimulus that does _________ _________ provoke pain.

Answer 2

Allodynia

Pain due to a stimulus that does not normally provoke pain.

Question 3

Dysesthesia

An _________ abnormal sensation, whether _________ or _________.

Answer 3

Dysesthesia

An unpleasant abnormal sensation, whether spontaneous or evoked.

Question 4

Hyperalgesia
An _________ response to a stimulus that is _________ painful. For pain evoked by stimuli that usually are not painful, the term _________ is preferred, whereas the term _________ is more appropriately used for cases with an increased response at a normal threshold or at an increased threshold, e.g., in patients with neuropathy.

Answer 4

Hyperalgesia
An increased response to a stimulus that is normally painful. For pain evoked by stimuli that usually are not painful, the term allodynia is preferred, whereas the term hyperalgesia is more appropriately used for cases with an increased response at a normal threshold or at an increased threshold, e.g., in patients with neuropathy.

Question 5

Hyperesthesia

Increased _________ to stimulation.

Answer 5

Hyperesthesia

Increased sensitivity to stimulation.

Question 6

Hyperpathia
A painful syndrome characterized by an _________ painful reaction to a stimulus, especially a _________ stimulus, as well as an _________ threshold.

Answer 6

Hyperpathia
A painful syndrome characterized by an abnormally painful reaction to a stimulus, especially a repetitive stimulus, as well as an increased threshold.

Question 7

Hypoalgesia

_________ pain in response to a _________ painful stimulus.

Answer 7

Hypoalgesia

Diminished pain in response to a normally painful stimulus.

Question 8

Hypoesthesia

_________ sensitivity to stimulation, excluding the special senses.

Answer 8

Hypoesthesia

Decreased sensitivity to stimulation, excluding the special senses.

Question 9

Neuralgia

Pain in the _________ of a nerve or nerves.

Answer 9

Neuralgia

Pain in the distribution of a nerve or nerves.

Question 10

Neuropathic Pain

Pain initiated or caused by a primary _________ or _________ in the nervous system.

Answer 10

Neuropathic Pain

Pain initiated or caused by a primary lesion or dysfunction in the nervous system.

Question 11

Neuropathy
A disturbance of _________ or _________ change in a nerve: in one nerve, _________; in several nerves, _________ _________; if diffuse and bilateral, _________.

Answer 11

Neuropathy
A disturbance of function or pathologic change in a nerve: in one nerve, mononeuropathy; in several nerves, mononeuropathy multiplex; if diffuse and bilateral, polyneuropathy.

Question 12

Paresthesia

An _________ sensation, whether spontaneous or evoked.

Answer 12

Paresthesia

An abnormal sensation, whether spontaneous or evoked.

Question 13

COMPLEX REGIONAL PAIN SYNDROME I
A relatively common disabling disorder.
Unknown pathophysiology.
Underlying mechanisms: changes in the peripheral and central _________-sensory, _________, and _________ processing systems and a pathologic interaction of _________ and _________ systems.

Answer 13

COMPLEX REGIONAL PAIN SYNDROME I
A relatively common disabling disorder
Unknown pathophysiology
Underlying mechanisms: changes in the peripheral and central somato-sensory, autonomic, and motor processing systems and a pathologic interaction of sympathetic and afferent systems

Question 14

Clinical Picture of CRPS
_________ extremity pain.
_________.
Autonomic (_________) and motor symptoms.

Answer 14

Clinical Picture of CRPS
Disproportionate extremity pain.
Swelling.
Autonomic (sympathetic) and motor symptoms.

Question 15

The condition can affect the upper or lower extremities, but it is slightly more common in the _________ extremities. CRPS I (also known as _________) is the definition given in the setting of known _________ to an area without specific _________ injury. CRPS II (also known as _________) is defined by a known injury to a _________. Causes may include trauma, underlying neurologic pathology, musculoskeletal disorders, and malignancy.

Answer 15

The condition can affect the upper or lower extremities, but it is slightly more common in the upper extremities. CRPS I (also known as RSD) is the definition given in the setting of known trauma to an area without specific nerve injury. CRPS II (also known as causalgia) is defined by a known injury to a nerve. Causes may include trauma, underlying neurologic pathology, musculoskeletal disorders, and malignancy.

Question 16

The characteristics of CRPS I/II according to the IASP are as follows:
_________ is reported in more than 90% of patients.
Most patients describe worsening of pain or other symptoms after exercising the affected limb.

Answer 16

The characteristics of CRPS I/II according to the IASP are as follows:
Pain.
Pain is reported in more than 90% of patients.
Most patients describe worsening of pain or other symptoms after exercising the affected limb.

Question 17

The characteristics of CRPS I/II according to the IASP are as follows:
_________.
Vascular abnormalities (often abnormal _________ and skin _________ in the early phase and _________ in the later stages) are characteristic symptoms of RSD/CRPS I.
Typically, patients with CRPS I exhibit a _________ and _________ affected extremity in the early stages and cold and pale skin in the later stages.

Answer 17

The characteristics of CRPS I/II according to the IASP are as follows:
Edema.
Vascular abnormalities (often abnormal vasodilation and skin warming in the early phase and vasoconstriction in the later stages) are characteristic symptoms of RSD/CRPS I.
Typically, patients with CRPS I exhibit a warm and vasodilated affected extremity in the early stages and cold and pale skin in the later stages.

Question 18

The characteristics of CRPS I/II according to the IASP are as follows:
Alteration in _________ function.
Although the IASP did not include _________ dysfunction within their formal criteria for diagnosing RSD (because it is not universal), they acknowledged that such dysfunction is common. The abnormal _________ symptoms that are reported most classically in RSD include the following:
Inability to _________ movement.
Weakness.
Tremor.
Muscle spasms.
Dystonia of the affected limb.
In one study, weakness was reported in 95% of patients, tremor of the affected limb in 49% of patients, and muscular incoordination in 54% of patients. In chronic RSD, severe spasms were present in 25% of patients.

Answer 18

The characteristics of CRPS I/II according to the IASP are as follows:
Alteration in motor function.
Although the IASP did not include motor dysfunction within their formal criteria for diagnosing RSD (because it is not universal), they acknowledged that such dysfunction is common. The abnormal motor symptoms that are reported most classically in RSD include the following:
Inability to initiate movement.
Weakness.
Tremor.
Muscle spasms.
Dystonia of the affected limb.
In one study, weakness was reported in 95% of patients, tremor of the affected limb in 49% of patients, and muscular incoordination in 54% of patients. In chronic RSD, severe spasms were present in 25% of patients.

Question 19

Alteration in _________ function – Although the IASP also decided not to include sensory dysfunction within their formal criteria for diagnosing RSD (due to variability), such symptoms, including hypoesthesia, hyper-esthesia, and allodynia, may occur.

Answer 19

Alteration in sensory function – Although the IASP also decided not to include sensory dysfunction within their formal criteria for diagnosing RSD (due to variability), such symptoms, including hypoesthesia, hyper-esthesia, and allodynia, may occur.

Question 20

CRPS is subdivided into the following three phases:
_________ stage: Usually _________ phase of _________ to _________ months.
_________ phase: _________ instability for several months.
_________ phase: Usually _________ extremity with _________ changes.

Answer 20

CRPS is subdivided into the following three phases:
Acute stage: Usually warm phase of 2 to 3 months
Dystrophic phase: Vasomotor instability for several months
Atrophic phase: Usually cold extremity with atrophic changes

Question 21

DIAGNOSIS/WORKUP

No single special investigation has been proven _________ and _________ enough to diagnose CRPS.

Answer 21

DIAGNOSIS/WORKUP

No single special investigation has been proven sensitive and specific enough to diagnose CRPS.

Question 22

Radiographic findings
X-ray imaging may show _________.
The triple phase bone scan has also been useful in diagnosis. According to Kozin et al.,1 scintigraphic abnormalities were reported in up to 60% of RSD patients and may be useful in arriving at the diagnosis of RSD. The most suggestive and sensitive findings on bone scan include _________ _________ activity in the _________ (third) phase, including juxtaarticular accentuation.
_________ thermography: can reveal temperature disparities between limbs.
_________.
Electrodiagnostic studies: NCV/EMG is usually _________.
Laser Doppler imaging.

Answer 22

Radiographic findings
X-ray imaging may show osteoporosis.
The triple phase bone scan has also been useful in diagnosis. According to Kozin et al.,1 scintigraphic abnormalities were reported in up to 60% of RSD patients and may be useful in arriving at the diagnosis of RSD. The most suggestive and sensitive findings on bone scan include diffuse increased activity in the delayed (third) phase, including juxtaarticular accentuation.
Skin thermography: can reveal temperature disparities between limbs.
QSART2.
Electrodiagnostic studies: NCV/EMG is usually normal.
Laser Doppler imaging.

Question 23

TREATMENT/MEDICATIONS
The mainstay of treatment for CRPS involves early restoration of _________.
Initiation of PT/OT program with focus on the affected limb.
Oral _________ early in course can help quell symptoms.

Answer 23

TREATMENT/MEDICATIONS
The mainstay of treatment for CRPS involves early restoration of function.
Initiation of PT/OT program with focus on the affected limb.
Oral steroids early in course can help quell symptoms.

Question 24

Sympathetic Blocks – good for _________ and _________ purposes:
_________ _________ block: good for UEx CRPS;
_________ _________ block: good for LEx CRPS.

Answer 24

Sympathetic Blocks – good for diagnostic and therapeutic purposes:
Stellate ganglion block: good for UEx CRPS;
Lumbar sympathetic block: good for LEx CRPS.

Question 25

Sympathectomy – can be performed interventionally (_________ and _________) or surgically.

Answer 25

Sympathectomy – can be performed interventionally (radiofrequency and cryoablation) or surgically.

Question 26

Dorsal Column Stimulation – can be a tremendous help with UEx/LEx CRPS. Appropriate diagnosis (good response to sympathetic block) and patient screening help to improve outcomes of _________.

Answer 26

Dorsal Column Stimulation – can be a tremendous help with UEx/LEx CRPS. Appropriate diagnosis (good response to sympathetic block) and patient screening help to improve outcomes of neuromodulation.

Question 27

The spinal cord gives off spinal nerves in pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. The spinal cord and nerves are surrounded by a sac called the _________ _________, which contains the CSF.

Answer 27

The spinal cord gives off spinal nerves in pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. The spinal cord and nerves are surrounded by a sac called the dura mater, which contains the CSF.

Question 28

As a rule of thumb, in the cervical spine, a nerve root comes out above its corresponding vertebral body, meaning that at C6/7, the C7 nerve root exits. At C7/T1, the C8 nerve root exits. The presence of C8 translates to the thoracic and lumbar nerve roots exiting _________ their corresponding vertebral body (Fig. 6-2).

Answer 28

As a rule of thumb, in the cervical spine, a nerve root comes out above its corresponding vertebral body, meaning that at C6/7, the C7 nerve root exits. At C7/T1, the C8 nerve root exits. The presence of C8 translates to the thoracic and lumbar nerve roots exiting below their corresponding vertebral body (Fig. 6-2).

Question 29

Similarly, the direction of the disc herniation can impact which nerve root is impacted. Posterolateral disk herniations typically _________ the root that exits at that level and affect the root exiting at the next level _________. The majority of disk herniations are posterolateral, given the additional support provided by the posterior longitudinal ligament (Fig. 6-3). Far lateral disk herniations can affect the nerve root at that level as it exits via the lateral recesses (Fig. 6-4).

Answer 29

Similarly, the direction of the disc herniation can impact which nerve root is impacted. Posterolateral disk herniations typically spare the root that exits at that level and affect the root exiting at the next level below. The majority of disk herniations are posterolateral, given the additional support provided by the posterior longitudinal ligament (Fig. 6-3). Far lateral disk herniations can affect the nerve root at that level as it exits via the lateral recesses (Fig. 6-4).

Question 30

Imaging of the spine plays a large role in the workup/evaluation of low back pain. X-rays are often the first-line imaging obtained. It is important to know how the normal anatomy appears in x-ray/CT/MRI to better appreciate spinal pathology when present (Fig. 6-5).
X-rays can demonstrate multiple pathologies including:
_________ changes.
_________ (best seen with flexion/extension films).
_________ fractures.
Intervertebral disk _________.
Lytic/blastic lesions.
Pathologic finding in spine diseases (e.g., ankylosing spondylosis).

Answer 30

Imaging of the spine plays a large role in the workup/evaluation of low back pain. X-rays are often the first-line imaging obtained. It is important to know how the normal anatomy appears in x-ray/CT/MRI to better appreciate spinal pathology when present (Fig. 6-5).
X-rays can demonstrate multiple pathologies including:
Spondylytic changes.
Instability (best seen with flexion/extension films).
Compression fractures.
Intervertebral disk degeneration.
Lytic/blastic lesions.
Pathologic finding in spine diseases (e.g., ankylosing spondylosis).

Question 31

CT and MRI are usually the next modalities ordered if further radio-graphic evaluation is warranted (Figs 6-6 and 6-7). Unless contraindicated, MRI is often ordered to evaluate for _________ tissue pathology (i.e., disk disease) and to better evaluate bony pathology (?) (e.g., assessing acuity of fracture).

Answer 31

CT and MRI are usually the next modalities ordered if further radio-graphic evaluation is warranted (Figs 6-6 and 6-7). Unless contraindicated, MRI is often ordered to evaluate for soft tissue pathology (i.e., disk disease) and to better evaluate bony pathology (?) (e.g., assessing acuity of fracture).

Question 32

The main MRI types are T1, T2, sagittal STIR, and T1 with fat suppression. Different tissues appear differently on different types, however.
Water and pathology: white on _________, dark on _________.
Fat: white on _________ and _________.
Bone cortex, stones, and ligaments: _________ on every type. Contusions are _________.

Answer 32

The main MRI types are T1, T2, sagittal STIR, and T1 with fat suppression. Different tissues appear differently on different types, however.
Water and pathology: white on T2, dark on T1.
Fat: white on T1 and T2.
Bone cortex, stones, and ligaments: dark on every type. Contusions are white.

Question 33

Among the most common complaints in the physiatrist’s office are neck and low back pain. Due to the interplay of multiple musculoskeletal and neurologic structures, many times the pain is _________ in origin. Nachemson reported that after approximately _________ month of symptoms, only _________% of patients will have definable disease or injury. Radiculopathic (nerve root) pain typically follows a dermatomal/ myotomal distribution and can stem from irritation from disk fragments, bone, and others. In the cervical spine, the most common roots involved are _________ and _________. The most commonly involved levels in the lumbar spine are _________ and _________. Again, a poignant physical exam with tests for root irritation (cervical loading/distraction and straight leg raising) aids in accurate diagnosis.

Answer 33

Among the most common complaints in the physiatrist’s office are neck and low back pain. Due to the interplay of multiple musculoskeletal and neurologic structures, many times the pain is multifactorial in origin. Nachemson reported that after approximately 1 month of symptoms, only 15% of patients will have definable disease or injury. Radiculopathic (nerve root) pain typically follows a dermatomal/ myotomal distribution and can stem from irritation from disk fragments, bone, and others. In the cervical spine, the most common roots involved are C6 and C7. The most commonly involved levels in the lumbar spine are L5 and S1. Again, a poignant physical exam with tests for root irritation (cervical loading/distraction and straight leg raising) aids in accurate diagnosis.

Question 34

Spinal Stenosis – Pain typically has a more _________ onset, with the patient complaining of pain that is worse after arising in the _________ as well as after ambulating a certain distance. The former is said to be due to the additive compression by engorged _________ _________ overnight. The latter is called _________ _________ (pain worsening when walking down a hill versus up the hill, which is vascular claudication). As in radiculopathic pain, symptoms and findings may have a dermatomal distribution but it tends to be more diffuse. Furthermore, spinal stenosis and degenerative disk disease are not mutually exclusive. More often than not, stenosis results from disk herniation/bulges coupled with spondylytic changes such as facet joint and ligament hypertrophy.

Answer 34

Spinal Stenosis – Pain typically has a more insidious onset, with the patient complaining of pain that is worse after arising in the morning as well as after ambulating a certain distance. The former is said to be due to the additive compression by engorged epidural veins overnight. The latter is called neurogenic claudication (pain worsening when walking down a hill versus up the hill, which is vascular claudication). As in radiculopathic pain, symptoms and findings may have a dermatomal distribution but it tends to be more diffuse. Furthermore, spinal stenosis and degenerative disk disease are not mutually exclusive. More often than not, stenosis results from disk herniation/bulges coupled with spondylytic changes such as facet joint and ligament hypertrophy.

Question 35

Sacroiliac Joint Pain – The sacrum supports the axial spine and in turn articulates with the iliac wings to form left and right sacroiliac (SI) joints. Myriad ligamentous and muscle attachments contribute to the stability of this joint. Imbalance in the joint can result from repeated lifting and bending, causing a shift on the anteroposterior axis. Repeated forces can cause stress on the _________ attachments and irritation of the joint lines. The SI joint lines are innervated by _________-_________ root levels and hence may cause radicular-type symptoms when irritated. Common areas of pain in SI joint pathologies include the ipsilateral _________ and greater _________ regions. While evaluating the SI joint as a pain source, one must obtain appropriate history, radiography, and tests for pathologic causes of sacroiliitis (i.e., ankylosing spondylosis). A variety of provocation maneuvers exist (i.e., _________ and _________ tests) to evaluate for SI joint dysfunction.

Answer 35

Sacroiliac Joint Pain – The sacrum supports the axial spine and in turn articulates with the iliac wings to form left and right sacroiliac (SI) joints. Myriad ligamentous and muscle attachments contribute to the stability of this joint. Imbalance in the joint can result from repeated lifting and bending, causing a shift on the anteroposterior axis. Repeated forces can cause stress on the myofascial attachments and irritation of the joint lines. The SI joint lines are innervated by L3-S1 root levels and hence may cause radicular-type symptoms when irritated. Common areas of pain in SI joint pathologies include the ipsilateral hip and greater trochanter regions. While evaluating the SI joint as a pain source, one must obtain appropriate history, radiography, and tests for pathologic causes of sacroiliitis (i.e., ankylosing spondylosis). A variety of provocation maneuvers exist (i.e., Faber and Gaenslen tests) to evaluate for SI joint dysfunction.

Question 36

Treatment of NECK/LOW BACK PAIN
Barring any emergencies, the mainstay of treatment starts with appropriate use of a short period of _________ and initiation of PT (i.e., “back school” and McKenzie treatment programs) along with the start of medications including _________ and _________-2 inhibitors. Over the past few years, multiple topical formulations for NSAID delivery have augmented the tools available to the physician. A tapering dose of oral _________ may also be given concomitantly.

Answer 36

Treatment of NECK/LOW BACK PAIN
Barring any emergencies, the mainstay of treatment starts with appropriate use of a short period of rest and initiation of PT (i.e., “back school” and McKenzie treatment programs) along with the start of medications including NSAIDs and COX-2 inhibitors. Over the past few years, multiple topical formulations for NSAID delivery have augmented the tools available to the physician. A tapering dose of oral steroid may also be given concomitantly.

Question 37

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
These injections involve the introduction of local anesthetics, opioids, or steroids that have utility in the management of pain of various etiologies. It is mainly performed in an _________ or _________ approach with a loss-of-resistance technique. This technique involves traversing the supraspinous ligament, interspinous ligament, and then the ligamentum flavum, after which a “sudden loss of resistance” equates entry of the epidural space.

Answer 37

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
These injections involve the introduction of local anesthetics, opioids, or steroids that have utility in the management of pain of various etiologies. It is mainly performed in an interlaminar or paramedian approach with a loss-of-resistance technique. This technique involves traversing the supraspinous ligament, interspinous ligament, and then the ligamentum flavum, after which a “sudden loss of resistance” equates entry of the epidural space.

Question 38

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
Indications:
Cervical/lumbar \_\_\_\_\_\_\_\_\_.
Pain from cervical/lumbar \_\_\_\_\_\_\_\_\_.
\_\_\_\_\_\_\_\_\_ syndrome.
Pain from vertebral compression fractures.
Diabetic polyneuropathy.
Phantom limb pain.
Chemotherapy-related neuropathy/plexopathy.
Cancer pain.
Diagnostic neural blockade to aid in differential workup of pain source (i.e., pelvic, back, groin, genital, and lower extremity pain).

Answer 38

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
Indications:
Cervical/lumbar radiculopathy.
Pain from cervical/lumbar spondylosis.
Postlaminectomy syndrome.
Pain from vertebral compression fractures.
Diabetic polyneuropathy.
Phantom limb pain.
Chemotherapy-related neuropathy/plexopathy.
Cancer pain.
Diagnostic neural blockade to aid in differential workup of pain source (i.e., pelvic, back, groin, genital, and lower extremity pain).

Question 39

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
Contraindications:
Local \_\_\_\_\_\_\_\_\_.
Patient on \_\_\_\_\_\_\_\_\_.
Coagulopathy.
Sepsis.

Answer 39

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
Contraindications:
Local infection.
Patient on anticoagulants.
Coagulopathy.
Sepsis.

Question 40

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
Complications:
_________ puncture – reported as 0.5% incidence,8 may result in CSF loss or introduction of air (pneumocephalus), responsible for significant postprocedure _________.
Intravenous needle placement given the preponderance of epidural veins/arteries.
Epidural hematoma – usually self-limiting. In setting of anticoagulation, it may cause cord compression, cauda equina syndrome paralysis, apnea, and death.
Infection – high chance of spread given epidural vascularity.
Urinary retention and incontinence.
Direct trauma to spinal cord/nerve roots.

Answer 40

SPINAL INTERVENTIONS
Cervical/Lumbar Epidural Nerve Blocks
Complications:
Dural puncture – reported as 0.5% incidence,8 may result in CSF loss or introduction of air (pneumocephalus), responsible for significant postprocedure headaches.
Intravenous needle placement given the preponderance of epidural veins/arteries.
Epidural hematoma – usually self-limiting. In setting of anticoagulation, it may cause cord compression, cauda equina syndrome paralysis, apnea, and death.
Infection – high chance of spread given epidural vascularity.
Urinary retention and incontinence.
Direct trauma to spinal cord/nerve roots.

Question 41

SPINAL INTERVENTIONS
Caudal Epidural Nerve Block
Though used relatively infrequently, this injection preceded its lumbar counterpart by nearly 20 years (1901).
Proper technique for the caudal ESI involves the patient positioned in a _________ or _________ position. The caudal space is approached through the _________ ligament that covers the sacral hiatus. The needle is placed over the _________ membrane at an angle of about 60° to the coronal plane and perpendicular to the other planes. There is usually a loss of resistance as the membrane is pierced. General indications/contraindications mimic those of the lumbar/cervical approaches where anatomically relevant.

There are, however, several key indications where the caudal injection may prevail:
prior _________ surgery – can distort anatomy making lumbar approach difficult (i.e., fusion and hardware in place)
patients on anticoagulation or coagulopathic therapy (since epidural venous plexus usually ends at S4)

Contraindications include infection, sepsis, pilonidal cysts, and congenital anomalies of dural sac and contents.
Complications include dural puncture, needle misplacement, hematoma/ecchymosis, infection, and urinary retention/incontinence.

Answer 41

SPINAL INTERVENTIONS
Caudal Epidural Nerve Block
Though used relatively infrequently, this injection preceded its lumbar counterpart by nearly 20 years (1901).
Proper technique for the caudal ESI involves the patient positioned in a lateral or prone position. The caudal space is approached through the sacrococcygeal ligament that covers the sacral hiatus. The needle is placed over the sacrococcygeal membrane at an angle of about 60° to the coronal plane and perpendicular to the other planes. There is usually a loss of resistance as the membrane is pierced. General indications/contraindications mimic those of the lumbar/cervical approaches where anatomically relevant.

There are, however, several key indications where the caudal injection may prevail:
prior lumbar surgery – can distort anatomy making lumbar approach difficult (i.e., fusion and hardware in place)
patients on anticoagulation or coagulopathic therapy (since epidural venous plexus usually ends at S4)

Contraindications include infection, sepsis, pilonidal cysts, and congenital anomalies of dural sac and contents.
Complications include dural puncture, needle misplacement, hematoma/ecchymosis, infection, and urinary retention/incontinence.

Question 42

Facet Joint Injection/Medial Branch Block
The cervical and lumbar facet (_________) joints have been considered significant sources of chronic neck and low back pain. The facet joints are _________, made up of the inferior articular process and the superior articular process of the vertebra one level below. They are also dually innervated, receiving inputs from the medial branch nerves of each level comprising the joint. For example, the L4/5 facet joint is innervated by the medial branches of _________ and _________. Facet blocks are performed by first properly identifying anatomic landmark, which involves oblique images at 10° to 40° from midline for best needle visualization with rotation by another 5° to 10° for joint visualization. Using proper imaging and feel, a mixture of dye, local anesthetic, and steroid is injected.

Indications:
When making the decision to inject the facet joint or perform a medial branch block, one must identify those with facet syndrome and which levels are symptomatic. Classically, this has been defined by dull, aching pain with tenderness on palpation over the facet joints with occasional overlying muscle spasm. Pain may be unilateral or bilateral with occasional radiation. Definitive diagnosis can be made with pain relief coming from the injection of local anesthetic into the facet joint.

Contraindications:
Like other injections, these should be avoided in those with medication allergies, systemic or local infection, or coagulopathies.

Complications:
The most common complication is a transient increase in pain. Other complications include dural penetration, spinal anesthesia, capsule rupture, infection, and vertebral artery puncture (cervical facets).

Answer 42

Facet Joint Injection/Medial Branch Block
The cervical and lumbar facet (zygapophyseal) joints have been considered significant sources of chronic neck and low back pain. The facet joints are diarthrodial, made up of the inferior articular process and the superior articular process of the vertebra one level below. They are also dually innervated, receiving inputs from the medial branch nerves of each level comprising the joint. For example, the L4/5 facet joint is innervated by the medial branches of L4 and L5. Facet blocks are performed by first properly identifying anatomic landmark, which involves oblique images at 10° to 40° from midline for best needle visualization with rotation by another 5° to 10° for joint visualization. Using proper imaging and feel, a mixture of dye, local anesthetic, and steroid is injected.

Indications:
When making the decision to inject the facet joint or perform a medial branch block, one must identify those with facet syndrome and which levels are symptomatic. Classically, this has been defined by dull, aching pain with tenderness on palpation over the facet joints with occasional overlying muscle spasm. Pain may be unilateral or bilateral with occasional radiation. Definitive diagnosis can be made with pain relief coming from the injection of local anesthetic into the facet joint.

Contraindications:
Like other injections, these should be avoided in those with medication allergies, systemic or local infection, or coagulopathies.

Complications:
The most common complication is a transient increase in pain. Other complications include dural penetration, spinal anesthesia, capsule rupture, infection, and vertebral artery puncture (cervical facets).

Question 43

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Nerve root blocks/transforaminal steroid injections are a useful tool in the workup for back pain, but they are used in a patient subset that differs from that in which facet joint blocks are used. Nerve root blocks attempt to anesthetize the desired nerve for diagnostic and therapeutic purposes. Steroids are used in an attempt to provide long-term relief, primarily in patients with radiculopathy. They can be utilized when physical exam and radiologic findings pinpoint a specific nerve root as cause for pain. Pressure on the nerve may result in an autoimmune response that can elicit pain. Because the venous drainage lies on the outside of the nerve, pressure on the nerve increases the venous pressure. The extrinsic forces on the nerve can lead to resultant ischemia and pain within the nerve root, with pain also being referred down the particular dermatome. Similar to the other injections, the SNRB involves placing a mixture of local anesthetic and steroid in the superior region of the neural foramen where the _________ nerve root exits.

Answer 43

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Nerve root blocks/transforaminal steroid injections are a useful tool in the workup for back pain, but they are used in a patient subset that differs from that in which facet joint blocks are used. Nerve root blocks attempt to anesthetize the desired nerve for diagnostic and therapeutic purposes. Steroids are used in an attempt to provide long-term relief, primarily in patients with radiculopathy. They can be utilized when physical exam and radiologic findings pinpoint a specific nerve root as cause for pain. Pressure on the nerve may result in an autoimmune response that can elicit pain. Because the venous drainage lies on the outside of the nerve, pressure on the nerve increases the venous pressure. The extrinsic forces on the nerve can lead to resultant ischemia and pain within the nerve root, with pain also being referred down the particular dermatome. Similar to the other injections, the SNRB involves placing a mixture of local anesthetic and steroid in the superior region of the neural foramen where the postganglionic nerve root exits.

Question 44

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Indications:
After discectomy in patients who have recurrent radiculopathy but no recurrent disk herniation, symptoms are often caused when scar tissue _________ the nerve. Many patients can be treated successfully by using _________.
In patients with disk herniations, nerve root blocks are helpful. Since the body naturally resolves 90% of disk herniations when given enough time, early pain relief is important to try to avoid surgery. The pain is believed to result from an inflammation of the nerve root more than from direct compression. As a result, potent antiinflammatories (steroid) work well in quelling the process.
The injections are also efficacious when facet joint hypertrophy or cysts cause an irritation of the nerve root, though not so much as with discogenic disease.

Answer 44

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Indications:
After discectomy in patients who have recurrent radiculopathy but no recurrent disk herniation, symptoms are often caused when scar tissue tethers the nerve. Many patients can be treated successfully by using SNRBs.
In patients with disk herniations, nerve root blocks are helpful. Since the body naturally resolves 90% of disk herniations when given enough time, early pain relief is important to try to avoid surgery. The pain is believed to result from an inflammation of the nerve root more than from direct compression. As a result, potent antiinflammatories (steroid) work well in quelling the process.
The injections are also efficacious when facet joint hypertrophy or cysts cause an irritation of the nerve root, though not so much as with discogenic disease.

Question 45

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Contraindications:
Include a history of _________ to local anesthetics or steroids, systemic or overlying infection, coagulopathy, or, in the case of facet joint injections, severe foraminal stenosis (which can become worse if an injection is made into the joint itself). Severe foraminal stenosis is a relative contraindication to intra-articular facet joint injections. Injections into the facet joints can cause joint swelling, worsening a preexisting foraminal stenosis.

Answer 45

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Contraindications:
Include a history of allergy to local anesthetics or steroids, systemic or overlying infection, coagulopathy, or, in the case of facet joint injections, severe foraminal stenosis (which can become worse if an injection is made into the joint itself). Severe foraminal stenosis is a relative contraindication to intra-articular facet joint injections. Injections into the facet joints can cause joint swelling, worsening a preexisting foraminal stenosis.

Question 46

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Complications:
Rare, but can include bleeding, infection, and allergic reactions.
Intravascular injection may be harmless, but it results in a suboptimal or false-negative result. Furthermore, intravascular injection can be dangerous if the agent is injected into the vertebral artery or radicular branches that enter the neural foramina at various levels.
Spinal cord infarcts have occurred from both cervical and lumbar SNRBs.
Direct trauma to the nerve root can occur via the spinal needle, causing increased pain and occasional root _________.
Spinal anesthesia may occur if local anesthetic is inadvertently injected into the nerve root sleeve.
During cervical procedures, doing so can lead to respiratory arrest. Some patients experience adverse effects from the steroids.
Consider the total steroid dose when performing injections at multiple levels.

Answer 46

Selective Nerve Root Blocks (SNRBs)/Transforaminal ESI
Complications:
Rare, but can include bleeding, infection, and allergic reactions.
Intravascular injection may be harmless, but it results in a suboptimal or false-negative result. Furthermore, intravascular injection can be dangerous if the agent is injected into the vertebral artery or radicular branches that enter the neural foramina at various levels.
Spinal cord infarcts have occurred from both cervical and lumbar SNRBs.
Direct trauma to the nerve root can occur via the spinal needle, causing increased pain and occasional root avulsion.
Spinal anesthesia may occur if local anesthetic is inadvertently injected into the nerve root sleeve.
During cervical procedures, doing so can lead to respiratory arrest. Some patients experience adverse effects from the steroids.
Consider the total steroid dose when performing injections at multiple levels.

Question 47

Sacroiliac Joint Injection
Indicated for sacroiliitis or chronic sacroiliac joint _________. Serves both diagnostic and therapeutic purposes. Under fluoroscopic guidance, the joint space is visualized. A spinal needle is then introduced at the junction of the posterior one-third of the joint line with the middle one-third of the joint. The posterior iliac spine obstructs the superior portion of the joint, making the lower portion of the joint easier to inject. Once the joint space is entered, a small amount of contrast is injected to confirm needle placement. Once the arthrogram is satisfactory, the medication, which is usually a mixture of anesthetic and steroid, is injected.

Answer 47

Sacroiliac Joint Injection
Indicated for sacroiliitis or chronic sacroiliac joint arthropathy. Serves both diagnostic and therapeutic purposes. Under fluoroscopic guidance, the joint space is visualized. A spinal needle is then introduced at the junction of the posterior one-third of the joint line with the middle one-third of the joint. The posterior iliac spine obstructs the superior portion of the joint, making the lower portion of the joint easier to inject. Once the joint space is entered, a small amount of contrast is injected to confirm needle placement. Once the arthrogram is satisfactory, the medication, which is usually a mixture of anesthetic and steroid, is injected.

Question 48

RADIOFREQUENCY ABLATION
Involves using a needle (electrode) to deliver a current in either a _________ (hot) or a _________ (cold) fashion to cause neurolysis of the nerves in the vicinity of the lesion created by the electrode. General indications include failed conservative treatments, transient relief from repeated medial branch blocks, or no indication for surgical intervention. Again, contraindications include coagulopathy, platelet dysfunction, and severe cardiopulmonary disease for procedures involving cervical and thoracic regions. Complications include local postprocedure soreness, sensorimotor deficits from improper needle placement, vascular trauma (cervical region), pneumothorax (thoracic), entry into subarachnoid space via neural foramen (dorsal root ganglion RF), diaphragmatic paralysis and hoarseness (from cervical sympathectomy RF), puncture of abdominal viscera (lumbar sympathectomy RF), or direct disk, cord, and nerve root trauma.

Answer 48

RADIOFREQUENCY ABLATION
Involves using a needle (electrode) to deliver a current in either a constant (hot) or a pulsatile (cold) fashion to cause neurolysis of the nerves in the vicinity of the lesion created by the electrode. General indications include failed conservative treatments, transient relief from repeated medial branch blocks, or no indication for surgical intervention. Again, contraindications include coagulopathy, platelet dysfunction, and severe cardiopulmonary disease for procedures involving cervical and thoracic regions. Complications include local postprocedure soreness, sensorimotor deficits from improper needle placement, vascular trauma (cervical region), pneumothorax (thoracic), entry into subarachnoid space via neural foramen (dorsal root ganglion RF), diaphragmatic paralysis and hoarseness (from cervical sympathectomy RF), puncture of abdominal viscera (lumbar sympathectomy RF), or direct disk, cord, and nerve root trauma.

Question 49

VERTEBROPLASTY/KYPHOPLASTY
A minimally invasive procedure aimed at treating the pain and spinal instability surrounding acute vertebral compression fractures from the age of 2 weeks to 1 year. Anecdotally, many practitioners use a 6 month age limit for compression fractures. Further indications for vertebroplasty include refractory pain from the fracture. Absolute contraindications include diskitis, sepsis, and osteomyelitis. Relative contraindications include significant spinal canal compromise secondary to bone fragments, fractures older than 2 years, >75% collapse of vertebral body, fractures above T5, and traumatic compression fractures or disruption of posterior vertebral body wall. Vertebroplasty focuses on treating pain, while kyphoplasty focuses on restoring stability and vertebral height. Vertebroplasty involves tunneling a large gauge needle into the vertebral body and injecting 3 to 5 mL of _________ cement into the vertebral body. Similarly, in _________, two balloons are introduced via catheter into the vertebral body. The inflated balloon restores height and then allows for filling with the cement.

Answer 49

VERTEBROPLASTY/KYPHOPLASTY
A minimally invasive procedure aimed at treating the pain and spinal instability surrounding acute vertebral compression fractures from the age of 2 weeks to 1 year. Anecdotally, many practitioners use a 6 month age limit for compression fractures. Further indications for vertebroplasty include refractory pain from the fracture. Absolute contraindications include diskitis, sepsis, and osteomyelitis. Relative contraindications include significant spinal canal compromise secondary to bone fragments, fractures older than 2 years, >75% collapse of vertebral body, fractures above T5, and traumatic compression fractures or disruption of posterior vertebral body wall. Vertebroplasty focuses on treating pain, while kyphoplasty focuses on restoring stability and vertebral height. Vertebroplasty involves tunneling a large gauge needle into the vertebral body and injecting 3 to 5 mL of methylmethacrylate cement into the vertebral body. Similarly, in kyphoplasty, two balloons are introduced via catheter into the vertebral body. The inflated balloon restores height and then allows for filling with the cement.

Question 50

Spinal Cord Stimulators – Stimulate dorsal column of the spinal cord to treat patients with chronic intractable pain. Though the exact mechanism is unknown, several theories exist including the “gate” theory and direct inhibition of pain pathways in the _________ tract. The SCS can either be totally implantable or have an external transmitter. SCS placement first involves a trial stage where the lead is placed and managed externally. The latter is internalized pending satisfactory results. Indications for SCS include failed neck/back surgery, peripheral neuropathy, _________ neuralgia, CRPS I/II, epidural fibrosis/arachnoiditis causing chronic pain, radiculopathy, phantom limb pain, and ischemic pain from peripheral vascular disease.
Most patients have had chronic pain for greater than 12 months that is refractive to other conservative therapies. Contraindications include coagulopathy, platelet dysfunction, local or systemic infection, and patients with psychological issues (i.e., drug seeking). The most common complications are scar formation, lead migration, and infection.
_________ has more recently begun to be used for peripheral stimulation in subcutaneous tissue with promising results. It has been used successfully for occipital neuralgia and recalcitrant trigeminal neuralgia, among others.

Answer 50

Spinal Cord Stimulators – Stimulate dorsal column of the spinal cord to treat patients with chronic intractable pain. Though the exact mechanism is unknown, several theories exist including the “gate” theory and direct inhibition of pain pathways in the spinothalamic tract. The SCS can either be totally implantable or have an external transmitter. SCS placement first involves a trial stage where the lead is placed and managed externally. The latter is internalized pending satisfactory results. Indications for SCS include failed neck/back surgery, peripheral neuropathy, postherpetic neuralgia, CRPS I/II, epidural fibrosis/arachnoiditis causing chronic pain, radiculopathy, phantom limb pain, and ischemic pain from peripheral vascular disease.
Most patients have had chronic pain for greater than 12 months that is refractive to other conservative therapies. Contraindications include coagulopathy, platelet dysfunction, local or systemic infection, and patients with psychological issues (i.e., drug seeking). The most common complications are scar formation, lead migration, and infection.
Neuromodulation has more recently begun to be used for peripheral stimulation in subcutaneous tissue with promising results. It has been used successfully for occipital neuralgia and recalcitrant trigeminal neuralgia, among others.

Question 51

INTRATHECAL PUMPS
Intrathecal pumps have a place in the management of chronic pain as well as spasticity. A catheter is inserted intrathecally and connected to a pump. Initially, during the trial, the pump is external. If a satisfactory result is achieved, a permanent catheter is placed intrathecally and is tunneled through the subcutaneous tissue to an internal pump that usually sits in a pocket in the anterior abdomen. The pump can then be adjusted to deliver different amounts of medication. Intrathecal infusion bypasses the blood–brain barrier and hence allows a more directed effect on brain and spinal neuroreceptors with less medication. Several medications are used in these pumps, with the two most common ones being preservative-free _________ and _________ (latter for spasticity management).

Answer 51

INTRATHECAL PUMPS
Intrathecal pumps have a place in the management of chronic pain as well as spasticity. A catheter is inserted intrathecally and connected to a pump. Initially, during the trial, the pump is external. If a satisfactory result is achieved, a permanent catheter is placed intrathecally and is tunneled through the subcutaneous tissue to an internal pump that usually sits in a pocket in the anterior abdomen. The pump can then be adjusted to deliver different amounts of medication. Intrathecal infusion bypasses the blood–brain barrier and hence allows a more directed effect on brain and spinal neuroreceptors with less medication. Several medications are used in these pumps, with the two most common ones being preservative-free morphine and baclofen for spasticity management.