Chapter 52 Postamputation Pain

Question 1

Amputation of a limb can lead to painful and nonpainful

sequelae such as

Answer 1

phantom sensations, telescoping, residual

limb (aka “stump”) pain, and phantom pain

Question 2

Reasons for Amputation

Answer 2

Vascular disease is responsible for approximately 77% of
major limb amputations, while trauma (21%) and cancer (2%) are less frequent causes. Among upper extremity amputees, trauma is the leading cause.

Question 3

Phantom sensations

Answer 3

by definition nonpainful physical perceptions that occur after a traumatic or surgical amputation
that is perceived as emanating from the missing body part

Question 4

Phantom sensations are common after

Answer 4

surgery,
with an incidence of 90% during the first 6 months.
A third of patients experience phantom sensations within
24 hr after their surgery

Question 5

Is Excision of a body part essential for phantom sensations?

Answer 5

Excision of a body part,

is not essential for phantom sensations

Question 6

Nonpainful phantom sensation may have various manifestations

including

Answer 6

kinetic sensations, and kinesthetic and

exteroceptive perceptions.

Question 7

Kinetic sensations are exemplified by

Answer 7

perception of movements in the amputated body region, such as flexion/extension of the toes

Question 8

Kinesthetic

perceptions are characterized by

Answer 8

distorted representations
in size or position of the missing body part (e.g., feeling
that the hand or foot is twisted).

Question 9

Exteroceptive perceptions can include

Answer 9

paresthesias, tingling, touch, pressure,

itching, heat, cold, and wetness

Question 10

Phantom sensations are commonly experienced

Answer 10

the distal portion of the limbs—hands and feet—possibly due to the rich innervation of these regions and the disproportionately large cortical representation of these regions in the homunculus.

Question 11

TELESCOPING

Answer 11

the perception of progressive shortening
of the phantom body part resulting in the sensation that
the distal part of the limb is becoming more proximal

Question 12

PHANTOM PAIN

Answer 12

the perception of a painful, unpleasant

sensation in the distribution of the missing or deafferentated body part.

Question 13

Phantom pain can vary in character, duration, frequency, and

intensity

Answer 13

It can present as sharp, dull, burning, squeezing,
cramping, shooting, or as a shock-like electrical sensation. Patients may occasionally complain of intermittent tremors or painful muscle spasms in the stump associated with paroxysms of phantom pain.

Question 14

phantom pain often changed in presentation

within the first 6 months after amputation

Answer 14

The characteristic
of the phantom pain changed from a mainly
exteroceptive-like pain (knife-like or sticking), localized in the entire limb or at least involving proximal parts of
the lost limb, to a mainly proprioceptive type of pain (squeezing or burning) localized in the distal parts of the amputated limb

Question 15

One factor that increases the incidence of

phantom pain after amputation is

Answer 15

the presence of pain in

the limb before the amputation

Question 16

Stump pain or residual limb pain

Answer 16

pain localized to the

residual body part following amputation.

Question 17

Stump pain

is often secondary to

Answer 17

local pathologic processes such as infection; lesions of the skin, soft tissue, or bone; heterotopic ossification (.50% in traumatic amputations); and local ischemia

Question 18

Stump pain is often secondary to local pathologic processes

Answer 18

These processes can generally be classified into the following categories: postsurgical
nociceptive, neurogenic, prosthogenic, arthrogenic, ischemic,
referred (usually from the spine or joints), sympathetically
maintained, or abnormal stump tissue (e.g., adhesive scar tissue)

Question 19

Stump pain can be localized to

Answer 19

superficial (localized to the scar region of the incision), felt deep in
the distal stump, or encompass the whole residual limb.

Question 20

Stump pain can frequently be differentiated from phantom pain based on

Answer 20

the fact that it is classically provoked

or exacerbated by traction or pressure, which often occurs during the use of a prosthesis.

Question 21

The management

of stump pain entails a

Answer 21

detailed history and physical exam that includes ensuring a proper fitting prosthesis

Question 22

Arthrogenic and referred stump pains are usually secondary

to

Answer 22

abnormal gait and asymmetrically distributed weight bearing, resulting in excessive stress on adjacent joints and/or lumbosacral spine structures. This can
lead to bursitis, accelerated arthritis, sacroiliac joint disease,
discogenic and facetogenic pain, and lumbosacral
radiculopathy.

Question 23

PHANTOM PHENOMENA AFTER

MASTECTOMY

Answer 23

Most of these phantom sensations are felt intermittently,
occurring once every 2 or 4 weeks. phantom pain is localized in the entire breast or around
the nipple

Question 24

PHANTOM PHENOMENA AFTER
MASTECTOMY

The onset of phantom sensation and/or pain almost always occurs within

Answer 24

3 months of surgery, with most cases occurring within 1 month.

Question 25

the only way to distinguish between true “phantom” pain and other sources of postmastectomy pain (e.g., intercostal brachial neuralgia, neuroma) may be via

Answer 25

a detailed history and | physical exam

Question 26

suggest | that phantom phenomena are the result of

Answer 26

interactions xbetween altered peripheral, spinal, and supraspinal mechanisms.

Question 27

Peripheral nerve damage during an | amputation initiates

Answer 27

axonal regeneration, resulting in a | neuroma.

Question 28

A positive Tinel’s sign

Answer 28

(tapping on the injured nerve or neuroma leading to pain in the phantom limb or stump) represents a classic feature on physical examination

Question 29

Afferent fibers in a neuroma develop

Answer 29

ectopic activity, | mechanical sensitivity, and chemosensitivity to catecholamines.

Question 30

ion channels regulation in phantom limp

Answer 30

Upregulation of voltage-sensitive sodium channels, downregulation of potassium channels, and expression of novel receptors in the neuroma alter the excitability of the affected neurons and increase afferent input.

Question 31

Injured neurons can generate new, nonfunctional connections (ephaptic cross-talk), resulting in

Answer 31

increased afferent input to the spinal cord. These changes may lead to spontaneous pain, and explain the amplification in pain caused by emotional distress and/or exposure to cold that leads to increased sympathetic discharge and circulating catecholamines

Question 32

Treatment of of phantom pain

Answer 32

Total spinal anesthesia, cordotomy, cordectomy, and spinal cord stimulation have at best yielded only modest relief of phantom pain; in some cases spinal anesthesia can precipitate the development or rekindling of phantom pain that previously subsided

Question 33

Peripheral nerve injury leads to

Answer 33

deafferentation— removal of afferent input to the dorsal column of the spinal cord—causing structural, neurochemical, and physiologic changes in central nervous system neurons. These changes result in functional alterations—plasticity—in central neurons that lead to spontaneous pain signals which are transmitted centrally

Question 34

Peripheral sensory input | at the level of the spinal cord also has inhibitory effects on the central transmission of pain.

Answer 34

Changes in the dorsal horn and the loss of afferent input lead to decreased impulses from brainstem reticular areas, which normally exert inhibitory effects on sensory transmission.

Question 35

the absence of inhibitory effects of sensory input from the missing peripheral body part causes

Answer 35

increased autonomous activity of dorsal horn neurons, in effect becoming “sensory epileptic discharges”.

Question 36

The brain exhibits neuroplastic changes both in motor | and sensory cortices

Answer 36

Cortical representation can be altered so that painful and nonpainful sensations in the phantom are a perceptual correlate of reorganizational processes in the somatosensory cortex

Question 37

The first step in the management of stump pain is to

Answer 37

identify a specific etiology for the pain that can be the target for developing treatment strategy. The stump should be carefully examined for a localized tender spot where a Tinel’s sign can be elicited suggestive of a neuroma. The stump should also be examined for ulcers, potential sites of inflammation or bony abnormalities, evidence of ischemia, or recurrence in the case of malignancy.

Question 38

changes in | gait and altered body mechanics may result in

Answer 38

musculoskeletal pain. Rehabilitation therapy to correct gait and postural compensations that result in arthritic or referred pain may be useful

Question 39

TENS

Answer 39

may be beneficial in 25% to | 50% of patients with stump pain

Question 40

Medication management | will depend on

Answer 40

whether the pain is suspected to be of somatic or neuropathic origin. In the former case, (NSAIDs), (COX-2) antagonists, and/or opioids may be indicated. Neuropathic pain resulting from neuromas should be treated with adjuvant analgesics such as tricyclic antidepressants (e.g., nortriptyline) and anticonvulsants (e.g., gabapentin).

Question 41

Surgical therapies are indicated only when

Answer 41

a specific rectifiable pathology is identified. Protruding bone, bony exostosis, wound infection, and poorly healed wounds are clear indications for surgery.

Question 42

A neuroma under constant | pressure or near a joint resulting in

Answer 42

repeated traction may be treated by excision of the neuroma and repositioning the nerve ending in bone or muscle

Question 43

Selective nerve blocks of peripheral nerves may be useful as a

Answer 43

prognostic indicator of the success of excision | of the neuroma

Question 44

Dorsal root entry zone (DREZ) lesioning

Answer 44

has not been effective in patients with isolated | stump pain.

Question 45

initiated in the preamputation phase

Answer 45

In the case of surgical amputations, educating and counseling the patient on the consequences of amputation, the rehabilitation process, and the prosthetic options

Question 46

Numerous treatment | approaches have been attempted for phantom pain

Answer 46

a wide variety of medications, physical therapy, psychological interventions such as cognitive behavioral therapies, complementary and alternative therapies, neurostimulation, and ablative procedures at various sites in the peripheral and central nervous systems.

Question 47

shown | to reduce phantom pain in the short term.

Answer 47

opioids, calcitonin, and ketamine

Question 48

First-line medication classes for the treatment of neuropathic pain include

Answer 48

gabapentinoid anticonvulsants and antidepressants

Question 49

employed as add-on or individual therapy when first line treatment is ineffective

Answer 49

beta-blockers, neuroleptic agents, mexiletine, and capsaicin

Question 50

Treatment for cramping pain, stump movement disorders, or flexor spasticity

Answer 50

baclofen or clonazepam may be effective

Question 51

Opioid therapy

Answer 51

has been shown to provide | short-term relief of stump and phantom pains

Question 52

offer temporary relief with | no proven meaningful long-term benefits

Answer 52

Various physical modalities such as ultrasound, vibration, TENS, and acupuncture. These therapies rely on the gate control theory of pain transmission, which proposes that stimulation of large nerve fibers “closes the gate” and inhibits the transmission of pain centrally

Question 53

Surgical interventions have not been shown to be of | significant benefit in phantom pain

Answer 53

Spinal cord stimulation has been recommended to replace the loss of afferent input to the dorsal column and enhance the descending inhibition of pain transmission.

Question 54

Psychological interventions for phantom pain include

Answer 54

hypnosis, biofeedback, cognitive and behavioral therapies, and support groups. These interventions may facilitate adaptation to a change in body image, adaptation to chronic pain, and relief of grief and anger

Question 55

Mirror therapy

Answer 55

has been successfully used to alleviate phantom pain by exploiting the brain’s predilection for prioritizing visual stimuli over proprioceptive and somatosensory input

Question 56

Mirror therapy approach

Answer 56

It involves strategically placing a mirror adjacent to the intact limb to give the illusion that the missing body part is present and can be purposefully moved. Because sensory experiences can be evoked by visual stimuli, mirror therapy increases spinal motor and cortical excitability

Question 57

Educational efforts, usually done in conjunction with | psychological preparation, can also be beneficial when utilized in the

Answer 57

pre-amputation and postamputation periods. These include early introduction and education regarding the use of a prosthesis, information on the care and treatment of the stump, and explanation of the rehabilitation process, which might include vocational retraining

Question 58

the optimal treatment of postamputation pain entails a multimodal approach that includes

Answer 58

possible preemptive analgesia, psychotherapy, education and rehabilitation, polypharmacy, and if indicated, procedural interventions.