PAIN!

Question 1

Where does pain come from?

Answer 1

Damaged tissue innervated by nociceptors or from absence of damage.
Unpleasant sensory and emotional experience associated w/ actual or potential tissue damage or described in such terms.

Question 2

Why is pain hard to simplify?

Answer 2

pain is Multidimensional.

Question 3

What is the most common symptom that causes pts to seek medical attention?

Answer 3

Pain

Question 4

Physical Therapy treated pain is generally what 2 types?

Answer 4

Inflammation or musculoskeletal or neurological tissues.

Question 5

Define Acute Pain

Answer 5

< 6 mo duration for which an underlying pathology can be identified…
It’s a symptom
It protects

( a person feels pains before tissue damage occurs.)
(Acute pain is not the same as acute inflammation.

Question 6

Define Chronic Pain

Answer 6

Persistent pain lasting longer than normal time for the healing process.
…it does not serve a protective purpose.
…it IS a disease.

Question 7

Define Referred Pain

Answer 7

Pain felt at a site away from it’s source.
(Pt has a shoulder injury and is complaining of pain in the arm near the elbow.)
(Heart attack victim feels pain in shoulder or jaw.)

Question 8

The characteristics of Acute Pain

What causes it?
Does it have distinct or indistinct onset?
What other body functions is it correlated with?
What is intensity related to?
How long does it last?
Is it good or bad?

Answer 8

Occurs as a result of tissue damage or potential tissue damage and is a symptom. (IASP)
It has a well-defined time of onset with clear pathology . (IASP)
ASsociated w increase in muscle tone, HR, BP and increased SNS activity.
Intensity is related to degree of tissue damage and inflammation.
It lasts as long as th enoxious stimuli persists.
It serves a useful and protective function.

Question 9

When does Acute Pain become Chronic Pain?

Answer 9

Pain that remains for months.
Cause of pain is gone.
This pain serves no purpose.
May result from ongoing nociceptive stimulation.

Question 10

Chronic Pain
How does chronic pain begin?
What may cause it?
It’s a multifactorial phenomenon, what are its 3 factors?
What are the four ways chronic pain is associated with the multifactorial phenomena?
What types of sensitization are common?

Answer 10

As acute pain or have no identifiable cause.
Ongoing nociceptive stimulation after noxious stimuli are no longer active.
Physical, Psychological, and Social dysfunction

1. Catastrophization–people have made the pain a big issue in their mind by overreacting to the problem.
2. Symptom magnification–they will rate things 12 out of 10…” this is worse than anything anyone has ever suffered.”
3. Fear avoidance***–of pain results in the person being afraid of going back to work or back to life.
4. Social isolation

Peripheral and Central Sensitization often occur

Question 11

Pain is perceived in the brain, but is felt in the location of injury.
Chronic pain may be secondary to what three things?

Answer 11

1. changes and sympathetic nervous system
2. reduced production of endogenous opioids (A drug that reduces pain and causes euphoria. We also produce opioids… Endogenous opioids to reduce pain. I.e. runners high.
3. sensitization of afferant nerves (turning up the volume on pain)
   Primary (first-order)
   ***Secondary (second order) in central nervous system
   –Central sensitization(windup)–pathways within the CNS discharged even after stimulation from first order neurons has ended.

Question 12

What kind of patients are at risk for developing chronic pain?

Successful treatment of chronic pain usually requires what kind of approach?

Answer 12

Multidisciplinary approach

(pain to be managed with modalities. Use cold early on to control inflammation. Do not push the patient too hard. Do things that are at the edge of pain without entering pain. Moving too fast can move into increased sensitization.

Question 13

The three types of referred pain.

Define dermatomal pain
Given example of a referral nerve to it area of innervation.
Define Sclerotomal Pain

Answer 13

Dermatomal pain–referred from a nerve root to it sensory distribution. (dorsal root ganglion is hypersensitive part of nerve cord. Very sensitive to pain. The ganglion is close to CNS but is far enough away to be PNS. If injury is close to ganglion, the injury will be felt far away.

An ulnar nerve lesion causing pain in the little finger and ring finger.

A lesion in one body part results in pain at another body part because these two body parts were derived from the same anatomic area embryonically. IE myocardial infarction causes left shoulder pain, or hip injury causes knee pain.

Question 14

Define specificity theory

When pain is generally felt in response to stimulation of peripheral nociceptors, which fibers have been stimulated?

Answer 14

Specific pain fibers are responsible for the transmission of pain sensation.

A delta and C fibers.

Question 15

Define pattern. theory

Central sensitization results in pain impulses originating where?

Answer 15

The sensation of pain results from an appropriate intensity or frequency of stimulation of receptors that also respond to touch, pressure or temperature.

Within the CNS.

Question 16

Neural Transmission

A-beta fibers are large diameter afferents that carry what?
A-delta and C fibers are small diameter afferents which carry what kind of impulses?

Answer 16

Non-nociceptor impulses.

Nociceptor impulses.

Question 17

Name seven neurotransmitters

Answer 17

acetylcholine
serotonin
norepinephrine
substance P
glutamate
enkephalins
B-endorphin

Question 18

C-fibers (80% of afferent pain-transmitting fibers)

Described c-fiber axon.
What kind of pain does it transmit?
How does the pain start and last?

Answer 18

small, unmyelinated, slow transmission of action potential.

Causes pain that is described as “dull, throbbing, aching, of burning”

Slow onset, long lasting, not well localized, difficult to deal with emotionally, can be accompanied by autonomic responses like sweating, increased HR and BP, and nausea. (Like the long last pain one feels after a brick falls on their bare foot. Usually provoked by the presence of chemical mediators at the injury site. )

Question 19

A delta-fibers (20% of pain transmitting fibers)
Describe a delta-fiber axon.
What kind of pain does it transmit?
How does the pain start and last?

Answer 19

small, myelinated, fast transmission of action potential.

Cause pain that can be described as “sharp, stabbing or pricking”

Quick onset, short duration, localized and not associated with emotional involvement. (Like the immediate pain one feels when a brick strikes their bare foot.)

Question 20

A-beta fibers (non-painful stimuli)

Describe the axon.
What kind of stimulus does it respond to?
What does current theory say?

Answer 20

large diameter, myelinated, fast transmission of action potential.

Respond to pressure, heat, cold, vibration (stimulate non-painful fibers in order to reduce pain,. even children do this naturally.)

**Currrent theories on pain describe these fibers can contribute to pain.

Question 21

How might A-beta fibers contribute to pain? 3

Answer 21

Activate sensitized 2nd order neurons.
May sprout fibers that extend into deeper layers in the spinal cord that are normally stimulated by C fibers.
They may just fire abnormally if near damaged nociceptive nerves.

Question 22

Ascending A-beta input Gate Control of Pain

Answer 22

Nociceptor (A-delta & C) is fired
Shoots a branch into the Interneuron in Substantia Gelatinosa.
Inhibits gelatinosa…Pain is uninhibited and stimulated T-cells.

Nonnociceptor (A-beta) is fired.
Shoots a branch into the Interneuron in Substantia Gelatinosa.
Stimulates Gelatinosa…Pain in inhibited at the T-cell.

Question 23

With the Ascending A-beta input Gate Control of Pain in mind, What type of stimuli would be induced with a physical agent to reduce a patient’s pain?

Answer 23

Heat
Pressure
Traction
E-stim
Ice
Massage

Question 24

Descending Theory – Central Biasing
(Motivation, relaxation techniques, diversion, positive thinking.)
What is the theory?

Answer 24

Still pain gating, but reducing pain by causin pain…Holding a trigger point in massage. Running and feel pain, then get the runner’s high.

Question 25

What is the sequence of events in descending pain control?

Answer 25

1. Incoming A-delta and C afferents…ouch impulses!
2. Transmission cells are stimulated…
3. Ouchy impulses are on their way to the brain.
4. Lower-level centers of the brain are stimualted. Higher centers also get involved.
5. Descending (efferent) impulses from the higher brain centers.
6. Pain inhibiting neurotrnasmitters are released back at the t-cells.