Neuropathic Pain, Pain Matrix Dysfunction, and Pain Syndromes Flashcards

1
Q

In neuropathic pain, pain matrix dysfunction, and pain syndromes pain is not a warning of tissue injury, rather it is a _____

A

disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is neuropathic pain?

A

Pain arising as a direct consequence of a lesion or disease affecting the somatosensory system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What genetic code predisposes someone to develop neuropathic pain?

A

Individuals with genetic codes that produce less of the enzyme that regulates the levels of catecholamine and encephalin are twice as likely to develop neuropathic pain as those who produce more of the enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 4 symptoms of neuropathic pain?

A
  • Paresthesia
  • Dysesthesia
  • Allodynia
  • Secondary Hyperalgesia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is parasthesia?

A

a painless abnormal sensation (tingling or prickling) in the absence of nociceptor stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is dysesthesia?

A

unpleasant abnormal sensation (buring pain or shooting electrical sensations), either evoked or spontaneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is allodynia?

A

pain evoked by a stimulus that normally would not cause pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is secondary hyperalgesia?

A

excessive sensitivity to stimuli that are normally mildly painful in uninjured tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 4 Mechanisms for Neuropathic Pain?

A
  • Ectopic foci
  • Ephaptic transmission
  • Central sensitization
  • Structural reorganization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the mechanism of ectopic foci

A

When myelin is damaged, signals from the exposed axon stimulate excessive production of mechanosensitive and chemosensitive ion channels. These channels are inserted into the demyelinated membrane, producing abnormal sensitivity to mechanical and chemical stimuli. The demyelinated regions take on a new, pathologic role of generating action potentials in addition to the normal role of conducting action potentials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How may ectopic foci contribute to the development of pain syndromes?

A

The sensitivity of ectopic foci to circulating catecholamines may contribute to the development of pain syndromes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where and why does ephaptic transmission occur?

A

It occurs in demyelinated regions due to a lack of insulation between neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is central sensitization?

A

Excessive responsiveness of central neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does central sensitization develop in response to?

A

Ongoing nociceptive input, but it even persists after the peripheral injury has healed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Central sensitization is created by what?

A

An increased availability of excitatory transmitters and an increased number of excitatory receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are 4 cellular changes that reflect central sensitization?

A
  • increased spontaneous activity
  • increased responsiveness to afferent inputs
  • prolonged afterdischarge in response to repeated stimuli
  • expansion of receptive fields
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does prolonged central sensitization lead to?

A

rewiring of connections in the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What structural changes occur in the dorsal horn?

A

Withdrawal of C-fiber axon terminals from the dorsal horn and growth of A(beta)-fiber axons into regions of the spinal cord that normally receives only C-fiber terminals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 3 sites in which neuropathic pain can arise from abnormal neural activity?

A
  • Periphery (e.g., nerve compression in carpal tunnel syndrome)
  • CNS in response to deafferentation
  • Dorsal horn
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does injury or disease of the peripheral nerves often result in?

A

sensory abnormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What do complete nerve resections result in?

A

a lack of sensation from that nerve’s receptive field

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do partially damaged nerve resections result in?

A

allodynia and sensations similar to an electric shock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does avulsion of dorsal roots from the spinal cord produce?

A

Deafferentation and causes people to feel burning pain in the area of sensory loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is deafferentation?

A

the interruption or destruction of the afferent connections of nerve cells

25
Q

What is phantom pain?

A

Pain that seems to originate from the missing limb of amputees

26
Q

What causes phantom pain?

A

The absence of sensory information from the amputated limb causes neurons in the central nociceptive pathways to become overactive

27
Q

What is neuropathic central pain?

A

Pain that is described as a burning, shooting, aching, freezing, or tingling pain caused by a lesion of the CNS that is usually localized to the area of the body deafferented by the lesion

28
Q

What is the site of pain after a spinal cord lesion? Why?

A

The thalamus, because the neurons in the VPL thalamic nucleus are spontaneously active without input from the spinal cord

29
Q

Central pain occurs in 30% of people who have what pathology?

A

multiple sclerosis

30
Q

What does small fiber neuropathy produce?

A

partial deafferentation and central sensitization

31
Q

What 3 pathologies cause deafferentation pain?

A
  • Postherpectic neurolgia
  • Diabetic neuropathy
  • Guillian-Barre syndrome
32
Q

What happens when the pain matrix malfunctions?

A

Top-down regulation of pain is disturbed, antinociception is reduced, and pronociception is intensified. All of which result in increased pain

33
Q

What are some examples of pathologies in which there is a disturbance of top-down regulation of pain?

A
  • fibromyalgia
  • episodic tension-type headache
  • migraine
  • chronic whiplash-associated disorder
34
Q

What is the fundamental problem behind fibromyalgia?

A

Abnormal processing of pain information, resulting in perception of pain without any painful stimulus external to the nervous system

35
Q

What is the primary symptom of fibromyalgia?

A

chronic widespread pain

36
Q

How should you treat fibromyalgia?

A
  • Aquatic therapy (with or without exercise)
  • Individualized aerobic exercise and strength training
  • A combination of OT/PT/cognitive therapy
37
Q

What are the 4 criteria for episodic tension-type headache (ETTH)?

A
  • Mild-to-moderate pain, usually bilateral
  • Lasting 30 minutes to 7 days
  • Not aggravated by physical activity
  • Not associated with nausea or vomiting
38
Q

What is the mechanism behind ETTH?

A

Supersensitivity to nitric oxide, a molecule used in transmission of nerve impuses

39
Q

_____ factors appear to be much more important that genetic factors in ETTH

A

Environmental (fumes, mold, light, noise, etc.)

40
Q

Migraine is a ______ disorder

A

neurogenic

41
Q

In migraine a disorder of sensory processing produces what?

A

a pain matrix malfunction that amplifies nociceptive signals in the trigemino-thalamo-cortical pathway

42
Q

List the 4 characteristics of migraine headaches, 2 of which someone must have in order to be diagnosed.

A
  • Unilateral location
  • Pulsating quality
  • Severity interfering with daily activities
  • Aggravation from routine physical activity
43
Q

During a migraine headache, what other symptoms that a patient may experience?

A
  • nausea, vomiting, photophobia, and photophobia
44
Q

What are the 4 signs that a headache may be caused by excessive pressure, hydrocephalus, or tumor?

A
  • Headache present at waking
  • Pain triggered by coughing, sneezing, or straining
  • Vomiting
  • Symptoms worsen when lying down
45
Q

What are the 4 signs that a headache is caused by serious intracranial disease, tumor, encephalitis, or meningitis?

A
  • Progressive, worsening over days or weeks
  • Neck stiffness, vomiting (irritation of meninges)
  • Rash, fever (bacterial meningitis, Lyme disease)
  • History of cancer, HIV, or infection
46
Q

What are the 3 signs that a headache may be caused by hemorrhage?

A
  • Headache after a head injury
  • Abrupt onset
  • Headache associated with onset of paralysis or reduced level of consciousness
47
Q

What is whiplash?

A

an injury to the neck resulting from rapid acceleration or deceleration

48
Q

What are the 2 syndromes that involve other systems in addition to the pain system?

A
  • Complex regional pain syndrome

- Chronic low back pain syndrome

49
Q

What does complex regional pain syndrome involve?

A

The somatosensory, autonomic, and motor systems

50
Q

What are the symptoms of complex regional pain syndrome?

A
  • intense pain in a limb
  • swelling
  • changes in skin color and temperature
  • sweating
  • atrophy
51
Q

What does chronic low back pain syndrome involve?

A

muscle guarding, disuse, and abnormal movements

52
Q

Although cutting selected dorsal roots or the spinothalamic tract should eliminate pain sensation, it often fails in practice, why?

A

The CNS changes in response to the original maintained pain or to pain-mediating fibers traveling in the dorsal columns

53
Q

What 3 things affect the experience of pain?

A
  • expectations
  • cognition
  • emotions
54
Q

What does the amount of pain an individual expects influence?

A

Processing in both the medial and lateral pain systems

55
Q

What are the 3 D’s of chronic pain?

A

Distress
Disuse
Disability

56
Q

What types of psychological interventions may decrease activation of the pain system and also improve coping skills?

A
  • Relaxation
  • Biofeedback
  • Cognitive behavioral therapy
  • Imagery
57
Q

What is placebo-associated improvement is defined as?

A

Any genuine psychological or physiologic effect that is attributable to receiving a substance or undergoing a procedure, but is not due to the inherent powers of that substance or procedure

58
Q

What should therapeutic approaches that want to mobilize placebo-associated improvement include?

A
  • positive (yet honest) communication about the therapy
  • providing encouragement and education
  • developing trust, compassion, and empathy
  • understanding the person as an individual
  • creating rituals that provide meaning and expectancy for the person
59
Q

What is the most conflict between people with chronic pain and HCPs?

A

Most patients with pain fell misunderstood and stigmatized by health care professionals. They wanted HCPs to acknowledge their pain as biologically based, whereas HCPs are frequently more concerned with the diagnosis and treatment than with providing biological explanations for chronic pain.