Pain description. Pain, Types of pain, pain pathways, pain theories, pain gate theory, pain modulation

1. PAIN-TYPES, PATHWAY,
THEORIES & MODULATION
DR. MUMUX MIRANI
BPT, MPT SPORTS, PHD SCHOLAR,
ASSISTANT PROFESSOR,
SPB PHYSIOTHERAPY COLLEGE, SURAT.

2. PAIN MEANS?
•Gujarati – દુઃખ
•Sanskrit - पीडा
•Hindi - वेदना
•Urdu – दर्द
•Spanish – dolor
•Russian – боль (bol)

3. PAIN
MEANS???

4. PAIN
MEANS???

5. BASIC DEFINITION
•Pain is an unpleasant sensory and emotional
experience associated with actual or potential
tissue damage.

6. TYPES OF PAIN
*Le you in pain
*Chronic pain
*Acute pain
* Nociceptive pain
*Visceral pain
*Neuropathic pain

7. TYPES OF PAIN:
• 1. Acute Pain: Short-term, resolves with healing (e.g., injury,
surgery)
• 2. Chronic Pain: Long-term, persists beyond healing (e.g., arthritis,
fibromyalgia)
• 3. Nociceptive Pain: Caused by tissue damage (e.g., burns, cuts)
• 4. Neuropathic Pain: Resulting from nerve damage (e.g., diabetes,
shingles)
• 5. Visceral Pain: Originating from internal organs (e.g.,
appendicitis, kidney stones)

8. 1. ACUTE PAIN
•- Duration: Short-term, usually less than 3-6 months
•- Cause: Injury, surgery, infection, or inflammation
•- Characteristics: - Sudden onset
•- Sharp, stabbing, or aching sensation
•- Usually resolves with healing
•- Example: post-operative pain, broken bone, or acute
appendicitis

9. 2. CHRONIC PAIN
•- Duration: Long-term, persists beyond 3-6 months
•- Cause: Ongoing conditions like arthritis, fibromyalgia, or
nerve damage
Characteristics:
•- Persistent or recurring pain
•- Can be dull, aching, or burning
•- Impacts daily life and mental health
•Example: chronic back pain, arthritis, or fibromyalgia

10. 3. NOCICEPTIVE PAIN
- Cause: Tissue damage or inflammation
Characteristics:
- Sharp, stabbing, or aching sensation
- Usually localized to the affected area
-Example: burns, cuts, fractures, or sprains-
Subtypes:
-Somatic nociceptive pain (skin, muscles, bones)
-Visceral nociceptive pain (internal organs)

11. 4. NEUROPATHIC PAIN-
•Cause: Nerve damage or dysfunction
Characteristics:
•- Burning, shooting, or stabbing sensation
•- Can be spontaneous or triggered by stimuli
•- Often accompanied by numbness, tingling, or weakness
•- Example: diabetic neuropathy, shingles, or multiple
sclerosis

12. 5. VISCERAL PAIN
•- Origin: Internal organs (e.g., abdomen, thorax, pelvis)
•- Cause: Inflammation, infection, or obstruction
•- Characteristics:
•- Dull, aching, or cramping sensation
•- Often referred to other areas (e.g., shoulder pain from
gallbladder issue)
•- Example: appendicitis, kidney stones, or inflammatory
bowel disease

13. PAIN PATHWAYS???

14. PAIN PATHWAY FLOWCHART

16. 1. TRANSDUCTION-
• Nociceptors: Specialized nerve endings that detect tissue damage,
inflammation, or other harmful stimuli
• Activation: Nociceptors respond to various stimuli, such as:
- Mechanical (pressure, stretch, vibration)
- Thermal (heat, cold)
- Chemical (inflammation, toxins)
- Electrical (direct stimulation)
- Signalling: Activated nociceptors release neurotransmitters, like substance P
and calcitonin gene-related peptide (CGRP), which transmit signals to the
spinal cord

17. 2. TRANSMISSION
• - Spinal Cord: Signals from nociceptors enter the spinal cord through dorsal
roots
• Ascending Pathways: Signals ascend through the spinal cord via:
- Spinothalamic tract (STT): transmits pain, temperature, and touch information
- Spinoreticular tract (SRT): involved in pain modulation and emotional response
- Spinomesencephalic tract (SMT): transmits pain information to the brainstem
- Nerve Fibers: Signals travel through A-delta (A )
δ and C fibers:
- Aδ fibers: fast, myelinated fibers transmitting sharp, localized pain
- C fibers: slow, unmyelinated fibers transmitting dull, aching pain

18. 3. PERCEPTION
• - Brainstem: Signals reach the brainstem, where they're processed and modified by
various structures:
• Periaqueductal gray (PAG): involved in pain modulation and emotional response
• Reticular formation: regulates arousal, attention, and pain perception
- Thalamus: Signals relayed to the thalamus, which acts as a sensory processing hub
- Cortex: Signals reach the somatosensory cortex, where pain is perceived and
interpreted:
- Primary somatosensory cortex (SI): processes basic sensory information
- Secondary somatosensory cortex (SII): involved in pain localization and intensity
- Insula: contributes to pain emotion, empathy, and interoception

19. • The brain interprets these signals as pain, taking into account various
factors, such as:
- Intensity
- Duration
- Location
- Quality (sharp, dull, burning, etc.)
- Emotional state
- Past experiences
- Expectations
- This complex process allows us to perceive and respond to pain, enabling
us to protect ourselves from harm and maintain homeostasis.

20. 3 THEORIES OF PAIN:
1. Specificity Theory
2. Pattern Theory
3. Gate Control Theory

21. 1. SPECIFICITY THEORY
• Proposed by: Max von Frey (1894)
• Key idea: Pain is a specific sensation with its own dedicated receptors and pathways
• Assumptions:
- Pain has its own unique sensory system
- Nociceptors detect specific painful stimuli
- Signals transmitted through specific pain pathways-
• Strengths:
- Explains why pain is a distinct sensation
- Supports the existence of nociceptors
• Weaknesses:
- Oversimplifies pain processing
- Doesn't account for individual differences in pain perception

22. 2. PATTERN THEORY
• Proposed by: Ronald Melzack and Patrick Wall (1962)
• -Key idea: Pain is a pattern of nerve activity interpreted by the brain
• Assumptions:
- Pain is a complex sensory experience
- Nerve activity patterns are decoded by the brain
- Context and past experiences influence pain perception
- Strengths: - Recognizes pain's subjective nature - Emphasizes the role
of brain processing
- Weaknesses: - Difficult to test and quantify - Doesn't fully explain
pain mechanisms

23. 3. GATE CONTROL THEORY
• Proposed by: Ronald Melzack and Patrick Wall (1965)
• Key idea: Pain is modulated by the brain's ability to gate or block signals-
• Assumptions:
- Pain signals can be blocked or reduced by other sensory inputs
- The brain acts as a "gate" controlling pain transmission
- Activation of certain nerves can close the gate, reducing pain
• Strengths:
- Explains pain modulation and relief
- Supports the use of alternative therapies (e.g., acupuncture)
• Weaknesses:
- Oversimplifies pain mechanisms
- Doesn't fully account for individual differences

26. PAIN MODULATION:
1. Ascending Pain Modulation
2. Descending Pain Modulation
3. Segmental Pain Modulation

27. 1. ASCENDING PAIN MODULATION
• Signals from nociceptors transmit to the spinal cord and brain
• Ascending pathways:
- Spinothalamic tract (STT): transmits pain, temperature, and touch
- Spinoreticular tract (SRT): involved in pain modulation and emotional
response
- Spinomesencephalic tract (SMT): transmits pain information to the brainstem
• Brain regions involved:
- Thalamus: relays sensory information
- Somatosensory cortex: processes pain location and intensity
- Limbic system: processes emotional aspects of pain

28. 2. DESCENDING PAIN MODULATION
• Brain sends signals to reduce pain transmission
• Mechanisms:
- Endogenous opioids (endorphins, enkephalins): natural painkillers
- Opioid receptors: activated by opioids, reducing pain transmission
- Monoamine systems (serotonin, noradrenaline): regulate pain modulation
• Descending pathways:
- Periaqueductal gray (PAG): sends signals to spinal cord to reduce pain
- Reticular formation: regulates arousal and pain modulation
- Rostral ventromedial medulla (RVM): sends signals to spinal cord to reduce
pain

29. 3. SEGMENTAL PAIN MODULATION
•Local spinal cord mechanisms modulate pain
•Mechanisms:
- Inhibition: reducing pain transmission
- Facilitation: enhancing pain transmission
- Gating: controlling pain transmission-
•Segmental pathways:
- Dorsal horn: receives and processes pain information
- Ventral horn: sends signals to muscles and glands
- Spinal interneurons: regulate pain modulation

30. SIDE NOTES:
•These pain modulation mechanisms interact and coordinate
to regulate pain perception.
•Understanding these processes helps develop effective
pain management strategies, including pharmacological
and non-pharmacological interventions.

31. THANK YOU.