PAIN - PowerPoint PPT Presentation

Loading...

PPT – PAIN PowerPoint presentation | free to download - id: 440549-YWU2M



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

PAIN

Description:

... THEORY Gate Control Theory Melzack and Wall 1965 A non-painful stimulus can ... wanted to map out pain in knee joint- scoped himself under ... Athletic Department ... – PowerPoint PPT presentation

Number of Views:1299
Avg rating:3.0/5.0
Slides: 36
Provided by: Athle6
Learn more at: http://www.uwec.edu
Category:
Tags: pain | athletic | knee | painful

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: PAIN


1
PAIN
2
PAIN- What is it?
  • Cardinal Sign of Inflammation
  • Mechanical deformation - trauma
  • Chemical irritation released by body
  • Prostaglandin Bradykinin Serotonin Histamine
  • Warning Sign
  • Limits Function
  • Has psychological/emotional affect

3
DEFINITION
  • An unpleasant physical and emotional experience
    which signifies tissue damage or potential for
    such damage -IASP, 1979

4
APPRECIATION
  • Must have knowledge to help athletes understand
  • May facilitate return to competition sooner
  • Acute injury care Pain control
  • Investigate Where, What, When

5
PAIN
  • Not completely Negative
  • Necessary for survival
  • Protective
  • Warning of impending injury
  • Something is wrong
  • Modalities
  • Use to decrease pain
  • Facilitate return to normal function

6
PATHWAYS
  • EFFERENT signals travel away from a central
    structure, those nerves leaving the CNS motor
    signals
  • AFFERENT signals travel toward a central
    structure, ex brain sensory signal

7
NERVES
  • RECEPTORS
  • Mechanoreceptors - pressure and touch stretch
  • Thermoreceptors - temperature and change
  • Proprioceptors - muscle length, tension, joint
    position
  • NOCICEPTORS - PAIN

8
RECEPTOR NERVE ENDINGS
  • Meissners Corpuscles (M) pressure, light touch
  • Pacinian Corpuscles (M) deep pressure
  • (P) joint position, vibration (superficial)
  • Merkels Cells (M) skin stretch, light touch
  • Ruffini Endings (P) change in position
  • Krausess End Bulbs (T) heat, cold
  • Golgi Tendon Organs (P) length, tension

9
NOCICEPTORS
  • Free Nerve Endings - pain impulses are sent to
    the brain via afferent pathways
  • Brain interprets these signals
  • Individualized response
  • Reflex loops
  • Afferent to spinal cord
  • Efferent back to site (motor) Afferent to brain
    (signal)

10
RESPONSIVE TISSUES
  • Very Sensitive
  • Skin, Joint Capsule, Bone (periosteum), Viscera
  • ex knee study
  • Sensitive
  • Subchondral Bone, Tendons, Ligaments

11
RESPONSIVE TISSUES
  • Limited Sensitivity
  • Muscle
  • Insensitive
  • Cartilage, Brain Tissue, Disc Nucleus
  • ex chondromalacia

12
AFFERENTS
  • First Order (Primary) Afferents
  • sensory nerve that courses outside the CNS
  • nerve fibers that transmit impulses from the
    sensory receptors
  • Subclassified
  • type A- myelinated
  • type C- unmyelinated

13
TYPE A
  • Categorized by diameter, conduction velocity,
    origin, and function.
  • Group I, II, IIIA
  • originate in deep muscle receptors
  • get progressively slower- less myelinated
  • serve proprioception, kinesthesia, pain from deep
    tissue damage

14
TYPE A CHARACTERISTICS
FIBERS
DIAMETER
CONDUCTION VELOCITY
IA 12-20 µm 72-120 µs IIA 6-12 µm 36-72
µs IIIA 1-6 µm 6-36 µs
15
A - BETA
  • More superficial - skin receptors
  • Large, myelinated mechanoreceptor
  • Respond to touch and low-intensity mechanical
    info (vibration)
  • Similar to AII fibers characteristics
  • Play role in Gate Control Theory

16
A-DELTA
  • Superficial - skin receptors
  • Large, thinly myelinated
  • Transmit information from warm/cold receptors and
    free nerve endings
  • touch, pressure, thermal
  • Respond to noxious mechanical stimulus (pinching,
    etc.) - PAIN

17
TYPE C AFFERENTS
  • Muscle and skin receptors
  • Small, slow conducting, unmyelinated
  • Deep mechano- and noci- few thermo-
  • Superficial noci- (50), thermo- (30), mechano-
  • Major player in relay of pain signals

18
PATHWAYS
  • Primary afferents synapse with secondary afferent
    fibers in the dorsal horn of the spinal cord
    (AIII, beta, delta, C) or travel to medulla in
    the dorsal column of cord (AI, AII)
  • Many pathways/tracts to carry sensory info to
    brain - 4 in dorsal spinal cord, 3 ventral

19
DORSAL COLUMN
  • Dorsal column-medial lemniscus pathway
  • Directly to medulla provides proprioception,
    touch, pressure
  • Spinocervical- superficial info
  • Postsynaptic dorsal column- mechano, noci
  • Dorsal spinocerebellar- joint receptors

20
VENTRAL COLUMN
  • Spinothalamic tract- 2nd order afferents
    classified as wide dynamic range (wide range of
    stimuli) or nociceptive (pain stimuli)
  • Spinoreticular tract- noxious stimulus terminate
    in reticular formation
  • Spinomesencephalic tract- noxious stim terminate
    in the periaqueductal gray (midbrain)

21
HIGHER CENTERS
  • Medulla Oblongata
  • Controls autonomic functions
  • Heart Rate
  • Respiration
  • Vomitting
  • Connects spinal cord to brain

22
Higher Centers
  • Reticular Formation
  • Located in brain stem
  • Influences alertness, waking, sleeping, and
    certain reflexes
  • Evokes motor, sensory, and autonomic response to
    noxious stimuli (rapid response)
  • Important relay in pain control mechanisms

23
HIGHER CENTERS
  • Thalamus
  • Divided into 2 nuclei
  • Ventral posterior lateral (VPL)
  • Synapses with fibers from body
  • Ventral posterior medial (VPM)
  • Synapses with fibers from head and face
  • Transmits stimuli to somatosensory cortex
  • Transmits stimuli to limbic system
  • Regulates emotional, autonomic, and endocrine
    response to pain

24
HIGHER CENTERS
  • Periaqueductal Gray
  • Significant role in pain modulation
  • Relay center for ascending and descending tracts
  • Hormonally controls the release of
    beta-endorphins and other pain reducing chemicals
  • Endorphins increase pain threshold

25
PUT IT ALL TOGETHER
Receptors
Trauma
A-delta C fibers
Afferent Pathway
Thalamus Reticular Formation PAG
Cortex Higher centers
ouch mommy
26
Pain / Spasm Cycle
  • Pain
  • Inflammation Spasm
  • Pain

27
PAIN CONTROL THEORY
  • Historical
  • Aristotle soul is the center of the sensory
    process pain located in the heart
  • 19th century Germans proved that the brain was
    involved with sensory and motor function
  • Specificity Theory direct pathway, continuous
    fiber
  • Pattern Theory generic nerve transmits code
    based on sensation various frequency, pattern

28
PAIN CONTROL THEORY
  • Gate Control Theory
  • Melzack and Wall 1965
  • A non-painful stimulus can block the transmission
    of a painful stimulus
  • Substantia Gelatinosa dorsal horn acts as a
    gate for sensory info A-beta fibers vs. A-delta
    and C fibers
  • T Cells transmission cell that connects sensory
    nerves to afferent tracts receives from SG
  • Example rubbing injury modalities

29
PAIN CONTROL THEORY
  • Levels Model (Castel, 1979)
  • Gate theory doesnt cover it all
  • Three levels
  • Involves higher central control
  • Endogenous Opiates

30
LEVELS THEORY I
  • Ascending Influence Pain Control
  • Similar to Gate Control Theory
  • Mechanics
  • Large diameter afferents synapse on enkephalin
    interneurons
  • Release of enkephalins into synapse of
    nociceptive pathways
  • Enkephalins believed to inhibit release of
    Substance P
  • Prohibits synaptic transmission of pain

31
LEVELS THEORY II
  • Descending Influence Pain Control
  • Higher brain centers modulate synaptic
    transmission in dorsal horn
  • Mechanics
  • Stimulus is received in Peri-Aqueductal Gray
    (PAG)
  • Third-order neurons from Raphe Nucleus are
    activiated
  • Dorsolateral tract descends from RN and synapse
    on enkephalin interneurons in lamina II releasing
    serotonin
  • Release of enkephalins into 1st and 2nd order
    afferent nociceptive pathway

32
LEVELS THEORY III
  • Beta-Endorphin Mediated Pain Control
  • Release of beta-endorphins has analgesic response
  • Mechanics
  • Hypothalamus is stimulated and synapses with PAG
  • Beta-endorphin released and activates
    dorsolateral tract
  • Serotonin released and enkephalin influence
  • Can be initiated by long term (20-40 min)
    electrical stimulation (motor level)
  • High intensity w/ long pulse duration

33
ASSESSMENT OF PAIN
  • Subjective finding
  • better, worse, same comparative
  • Scales, Questionnaires
  • Regardless of situation, must understand that
    individuals experience and respond to pain
    differently

34
CLINICAL PAIN
  • Local - self defined symptoms are at the site of
    the problem
  • Referred - pain in an area of the body not
    related to the injury
  • Radiating - usually associate with a spinal
    nerve seen in a dermatomal pattern
  • Trigger Points - localized area of spasm within a
    muscle

35
PAIN
About PowerShow.com