Physio Ii Test 3: Neuro Lectures 3-4 : Pain

Front 1

difference btwn Primary and secondary hyperalgesia?

Back 1

Primary = peripheral sensitization, -local tissue damage
-due to chemical mediators
Secondary = central sensitizatoin
-C fiber activity
-due to increased EPSP in dorsal horn

Front 2

5 types of chemical mediators that can be responsible for primary hyperalgesia?

Back 2

1)K+ from cell interior
2)5-hydroxytryptamine (5-HT, serotonin) from platelets
3)histamine from Mast cells
4)bradykinin from plasma
5)prostaglandins from cells

Front 3

neurogenic inflammation

Back 3

-type of primary hyperalgesia
-subtance P and CGRP are released and cause histamine release from mast cells. Cause vasodilation and edema.

Front 4

Function of substance P

Back 4

-produces slow, long lasting depolarization

Front 5

describe the "wind up" phenomenon

Back 5

-secondary hyperalgesia
-glutamate released from C fibers acting on NMDA receptors on dorsal horn
-If persists: Long-term potentation
-Substance P + CGRP involved
-NMDA receptor activation --> nociceptive neurons in dorsal horn--> increase in transmitter receptors. This causes supersensitivity and hyperexcitability= spontaneous pain

Front 6

allodynia

Back 6

pain in response to a stimulus which does not normally produce pain

Front 7

How is allodynia caused by mechanoreceptors projecting to neurons in the nociceptive pathway?

Back 7

-after injury, central nociceptive neurons become sensitized (central sensitization) and now mechanoreceptors input excites second order nociceptive neurons

Front 8

allodynia only occurs if ______ is present

Back 8

central sensitization

Front 9

Allodynia vs hyperalgesia?

Back 9

-allodynia= painful response due to mechanoreceptive fibers A(beta)
-hyperalgesia= enhanced pain due to nociceptive fibers A(delta)

Front 10

visceral pain receptors are especially sensitive to what?

Back 10

distention

Front 11

How are silent receptors activated in visceral pain?

Back 11

-inflammation or hyperemia produces primary hyperalgesia which reduces threshhold of regular nociceptors and activates the silent nociceptors

Front 12

guarding

Back 12

-visceral pain which initiates contraction of overlying skeletal muscle
-this is accomplished thru a reflex pathway

Front 13

How does neuropathic pain arise?

Back 13

-results form injury to neurons in the PNS (peripheral neuropathic pain) or CNS (central neuropathic pain) and NOT from activation of nociceptors

Front 14

Deaffernatation (neuropathic pain)

Back 14

-loss of afferent input to cord (as brachial plexus avulsion)
-produces burning pain in denervated dermatomes
-due to sensitivity and hyperactivity of dorsal neurons in denervated region

Front 15

causalgia

Back 15

-reflex sympathetic dystrophy syndrome
-after a peripheral nerve injury, damaged sensory fibers trigger spontaneous burning which gets worse with time.

Front 16

Why does causalgia happen?

Back 16

-Due to expression of alpha receptors on damaged sensory fibers
-sympathetic efferent activity stimulates these damaged fibers producing severe pain (sympathetically mediated pain)

Front 17

How can you stop causalgia?

Back 17

By blocking sympathetic activity or depleting catecholamines

Front 18

dorsal root irritation

Back 18

-compression or inflammation of dorsal roots
-abnormalities of sensation in dermatomes
1)pain
2)parathesia
3)hypesthesia
4)anesthesia

Front 19

parathesia

Back 19

spontaneous sensations of prickling, tingling or numbness

Front 20

hyperesthesia

Back 20

diminished sensitivity due to loss of afferents

Front 21

Thalamic syndrome

Back 21

-usually produced by vascular accident-blockade of a branch of the posterior cerebral artery (thalamogeniculate arterties)
-produces intense intractable pain on contralateral side of body

Front 22

What is the difference between nociceptive pain and referred pain

Back 22

nociceptive pain involves stimulation of nociceptors

neurogenic pain involves nerve injury. This pain does not involve the activation of nociceptors,

Front 23

visceral pain receptors are especially sensitive to what type of stimulus?

Back 23

stretch

Front 24

When patients feel pain in the amputated limb it in part to what?

Back 24

Secondary (central) hyperalgesia.

Front 25

causalgia is also know as

Back 25

reflex sympathetic dystrophy syndrome

Front 26

neuropathic pain caused by bullet wound or shrapnel.

Back 26

causalgia

Front 27

3 causes of Trigeminal neuralgia

Back 27

1)mcc enlarged looping vessel pressing on the trigeminal. the repeated pulses
2)multiple sclerosis
3)tumor

Front 28

intermittent claudication

Back 28

pain produced during muscular exertion because of occlusive vascular disease.

Front 29

What chemical agent is thought to be involved in muscle pain of vascular origen: intermittent claudication & angina pectoris

Back 29

K+ reslased during contraction, that accumulates in the absence of normal blood flow and cause pain. K+ depolarizes nociceptors,

Front 30

what is the most most prominent and best studied tract for pain?

Back 30

lateral spinothalamic tract

Front 31

nalaxone

Back 31

mu receptor opiate antagonist

Front 32

T/F Direct brain stimulation (periaqueductal gray matter) may result in either analgesia or hyperalgesia

Back 32

T, It is like that both the analgesic and hyperalgesic pathways are activated simultaneously.

Front 33

opiate-induced hyperalgesia

Back 33

ween patient of opiate they have a much lower threshold for pain.

Front 34

Does opiate induced analgesia has a direct actions on ______

Back 34

CNS (not on peripheral receptors)

Front 35

Chronic inflammatory pain

Back 35

-pains extending beyond the time of healing
-occurs in response to tissue injury or invading foreign substances
-damaged tissue --> release inflammatory mediators that sensitize/activate local nociceptors
-prostaglandins
-bradykinin
-histamine
-adenosine
-resulting in hypersensitivity and spontaneous persistent pain.
-Ex: arthritis

Front 36

Chronic neuropathic pain

Back 36

?

Front 37

Prialt the synthetic version of w-conotoxin is useful in the treatment of what channel associated with chronic pain?

Back 37

Preialt is N-type Ca channel blocker

Front 38

"The most painful disease in all of medicine" or suicide disease

Back 38

Trigeminal Neuralgia

Front 39

cause of Trigeminal Neuralgia?

Back 39

1)enlarged artery/vein pressing on Trigeminal nerve root in brain stem. The pulsations cause irritation and abnormal signals.

2) tumor
3) multiple sclerosis

Front 40

What pain type can manifest as a tooth ache?

Back 40

Trigeminal Neuralgia

Front 41

Cause of Muscle pain?

Back 41

occlusion of blood supply to muscle which results in K+ accumulation (no blood flow to move it out). K+ depolarizes nociceptors.

Front 42

Causalgia

Back 42

1) peripheral nerve injury by gunshot.

2) alpha receptors incorporated into membrane of damaged sensory fibers and sympathetic efferent innervate.

3) When sympathetic nerves fire it stimulates injured neruron causing sympathetic mediated pain.

Front 43

Pain, Paresthesia, hypesthesia, anesthesia are associated with what type of pain

Back 43

Dorsal root irritation

compression/irritation of dorsal root by slipped disks, disk degeneration, bone spurs

Basically anything that puts pressure on the dorsal roots, likelihood increases with age

Front 44

Paresthesia

Back 44

pins/needles

Front 45

hypesthesia

Back 45

diminished sensitivity due to loss of afferents.

diminished sensation

Front 46

anesthesia

Back 46

absence of sensation

Front 47

If you have pain on the right side and suspect Thalamic syndrome...what is the cause?

Back 47

Thalamic syndrome is caused by cranial artery compression of the thalamus which manifests pain on the the contralateral side.

So the thalamus on the left side would be of interest.

Front 48

Why should you suspect there is a problem with the diaphram when the patient has pain in his neck and shoulder.

Back 48

The diaphragm (visceral) and cutaneous nociceptors (somatic) of the neck and shoulders converge on the same spinothalamic neurons in the spinal cord (C3,C4). The brain interprets the pain as more likely coming from the skin leading to referred visceral pain

Front 49

What is the dematomal rule and what type of pain is associated.

Back 49

The dematomal rule states:
pain is referred to a cutaneous structure innervated by the dame dermatome as the visceral organ.

Referred visceral pain

Front 50

Neuropathic pain vs. Nociceptive pain

Back 50

Neuropathic pain results from injury to neruons of the PNS or CNS. Pain is not produced by direct activation of nociceptors.

Nociceptive pain: Pain produced by direct activation of nociceptors.

Front 51

Phantom limb syndrome

1) cause of pain
2) why can you feel the phantom thumb on your cheek?

Back 51

1) pain is caused by super-sensitivity and hyperactivity of dorsal horn neurons

2)Cortical remapping occurs where the cortical neurons innervate the dormant phantom limb neurons

Front 52

sympathetic mediated pain is associated with

Back 52

causalgia

Front 53

The gate control theory states that spinal modulation of pain can occur by large afferent inputs.

What are these large afferent inputs?

Back 53

If you burn yourself small C-fiber afferents will
1) inhibit inhibitory interneurons
2) stimulate 2nd order Projections neruons that cross the midline and send the pain signal up to the thalamus.

To reduce nociceptor c-fiber acitivity a person can rub the boo-boo and stimulate mechanorecptors. Signal then travels through their "large A-Beta afferent fibers" and stimulate the inhibitory interneuron which will inhibit the second order projection neuron that is sending the pain signal. This reduces
3)

Front 54

Why should you suspect there is a problem with the diaphram when the patient has pain in his neck and shoulder.

Back 54

The diaphragm (visceral) and cutaneous nociceptors (somatic) of the neck and shoulders converge on the same spinothalamic neurons in the spinal cord (C3,C4). The brain interprets the pain as more likely coming from the skin leading to referred visceral pain

Front 55

What is the dematomal rule and what type of pain is associated.

Back 55

The dematomal rule states:
pain is referred to a cutaneous structure innervated by the dame dermatome as the visceral organ.

Referred visceral pain