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![ Acute Pain
Pain that is caused by noxious stimulation due to
injury ,a disease process , or the abnormal function of
muscle or viscera
Two types of
1- acute [nociceptive]pain
2- somatic and visceral](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-12-2048.jpg)
![[somasthetic] [From viscera]
Superficial [from skin and
subcutaneous tissue]
eg.superficial cuts/burns etc.
Deep [from muscle
/bone/fascia/periosteum ]
eg.fracture
/arthritis/fibrositis,rupture of
muscle belly.](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-13-2048.jpg)
![Neuropathic Pain
Definition –Pain that is caused by a lesion or disease of the somatosensory
system [PNS or CNS]
Pain is not well localized , pathologic pain
Peripheral Nerves
-Traumatic brachial plexus injury
-Diabetes mellitus
-Carpel tunnel syndrome
-Post herpetic neuralgia
Central Nervous System
-Central post stroke pain
-Neuropathic association with spinal cord injury](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-15-2048.jpg)
![Pain Receptors
Sensory Receptor
At the distal terminals are the afferent [sensory] nerve specialized
sensory receptor that respond to physical or chemical stimuli
Once these receptor are adequately stimulated ,an impulse is generated
in the primary afferent neuron that is carried centrally into the CNS
Classified in 3 Group
1. Exteroreceptors
2. Proprioceptors
3. Interorecepters](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-26-2048.jpg)
![EXTERORECEPTORS
Stimulated by immediate external environment
Provide information from the skin and mucosa
Eg-
1. Merkel’s corpuscles [tactile receptors in the submucosa of tongue]
2. Meissner’s corpuscles tactile receptors in skin
3. Free nerve ending perceive superficial pain and touch](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-27-2048.jpg)
![Neural Pain Pathway
Sensory input from various stimuli [either external or
internal ] is received by specific peripheral receptor
called as nociceptors
Nocicepters respond as transducers and transmit
impulse
Perception of pain
Found in all parts of body](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-30-2048.jpg)
![Sensory Neuron
FIRST ORDER NEURON
[POSTERIOR NERVE ROOT GANGLIA]
SECOND ORDER NEURON
[SUBSTANTIA GELATINOSA]
THIRD ORDER NEURON
[THALAMIC NUCLEUS,
RETICULAR FORMATION ,
TECTUM ,GREY MATTER,SOMATOSENSORY]](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-32-2048.jpg)
![Peripheral mechanism of injury induced
pain[NEUROPHYSIOLOGY OF PAIN ]
TRANSDUCTON
TRANSMISSION
PERCEPTION
MODULATION](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-36-2048.jpg)
![Bradykinin +Leukotriene +Prostaglandins [PG stimulates nociceptors directly]
Increases plasma extravasation
Edema
Leukotriene stimulates nociceptors indirectly by PMNs
Release Chemical mediators
Stimulates nociceptor](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-38-2048.jpg)
![Pain Pathway
Pain
[Receptor]
Free nerve ending
Posterior nerve root Ganglion [First order neuron ]
Fibers from lateral spinothalamic tract [Second order neuron ]
Ventral posterolateral nucleus of thalamus ,reticular formation and midbrain [Third
order neuron]
Sensory Cortex [Center]](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-43-2048.jpg)
![ Destructive Surgery
• Glycerol Injection deposition of glycerol at this point
cause damage to the nerve to hinder pain signals
• Radiofrequency –application of a heated needle to
damage the nerve
• Sterotactic Radiosurgery [Gamma knife surgery] – is a
form of radiation therapy that focuses high power
energy on a small area of body](https://image.slidesharecdn.com/pathwayphysiologyperceptionofpain-201127083013/75/Pathway-physiology-perception-of-pain-67-2048.jpg)
Pathway , physiology , perception of pain
This document discusses the pathway, physiology, and perception of pain. It begins with an introduction to pain and its significance as a warning signal. It then covers the history of theories about pain. The document defines pain and discusses its characteristics such as threshold, intensity, and localization. It classifies pain into acute and chronic types and looks at the components involved in pain perception including receptors, neural pathways, and sensory neurons. The document examines peripheral mechanisms of injury-induced pain and theories of pain such as the gate control theory. It also discusses visceral pain, referred pain, and tooth pain pathways.
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Similar to Pathway , physiology , perception of pain
More from Maharashtra University of Health sciences ,Nashik
Pathway , physiology , perception of pain
- 1. Pathway , physiology, perception Of Pain Pathway , physiology , perception Of Pain Presented by – Dr.Zareesh.S.Akhtar 1 Year M.D.S In dept of ODMR
- 2. Contents Introduction Significance History Definition Characteristics Of Pain Classification of pain Components Of Pain Pain receptors Neural pain Pathway Sensory Neuron Peripheral mechanism of injury induced pain
- 3. Visual AnalogueScale Applied Physiology Applied Clinical Aspect Conclusion Reference Pathways of pain Theories Of Pain Visceral Pain Referred Pain Tooth Pain
- 4. Introduction Pain isdefined as unpleasant and emotional experience associated with or without actual tissue damage. Pain sensation is described in many ways like sharp ,pricking ,electrical dull aching, shooting , cutting ,stabbing , trobbing etc. As such pain is typically associated with noxious stimuli ,events that are potentially or actually damaging to tissue.
- 5.
- 6. Significance Of Pain Pain gives us warning signal about the problem /Injury. Pain prevents further damage by causing reflex withdrawal of the body from source of the injury. Pain urges the person to take proper treatment to prevent major damage.
- 7. History Derived fromLatin Word ‘Poena’- Punishment from God Derived from Greek word –’poin’ Bible –Reference to pain not only in relationship to injury or illness but also anguish of soul Aristotle - considered pain to be the ‘passion of the soul’ Plato –contented pain and pleasure arose from within the body
- 8. Definition “An unpleasant sensoryand emotional experience associated with actual or potential tissue damage or described in term of such damage” -IASP “ An unpleasant emotional experience usually initiated by a noxious stimulus and transmitted over a specialized neural network to the central nervous system where it is interpreted as such ” -Monheim.
- 9. Characteristics Of Pain 1.Thresholdand Intensity - If the intensity of the stimuli is below the threshold (Sub- Threshold) Pain is not felt. - As the intensity increases more and more ,pan is felt more and more according to Webers-frecher’s Law (This law ensures that while our body can perceive pain due to low intensity stimulus ,a severe crushing injury will not cause death due to pain sensation ,yet as stimulus increases ,sense of perception also increases .)
- 10. 2.Adaptation - Pain receptorsshow no adaption and so the pain continues as long a receptors continue to be stimulated. 3.Localization of Pain - Pain sensation is somewhat poorly localized .However superficial pain is comparatively better localized than deep pain. 4.Influence of the rate of damage on intensity of pain - If the rate of tissue injury is high ,intensity of pain is also high
- 11. Classification Of Pain BasisType of Pain Duration Acute Chronic Mechanism Nociceptive(physiological) Neuropathic(pathological)
- 12. Acute Pain Pain that is caused by noxious stimulation due to injury ,a disease process , or the abnormal function of muscle or viscera Two types of 1- acute [nociceptive]pain 2- somatic and visceral
- 13. [somasthetic] [From viscera] Superficial[from skin and subcutaneous tissue] eg.superficial cuts/burns etc. Deep [from muscle /bone/fascia/periosteum ] eg.fracture /arthritis/fibrositis,rupture of muscle belly.
- 14. Chronic Pain Pain that extend 3to 6 month beyond onset beyond the expected period of healing It may be nociceptive ,inflammatory ,neuropathic or functional in origin A distinguishing feature is that psychological mechanisms or environmental factors frequently play a major role.
- 15. Neuropathic Pain Definition –Painthat is caused by a lesion or disease of the somatosensory system [PNS or CNS] Pain is not well localized , pathologic pain Peripheral Nerves -Traumatic brachial plexus injury -Diabetes mellitus -Carpel tunnel syndrome -Post herpetic neuralgia Central Nervous System -Central post stroke pain -Neuropathic association with spinal cord injury
- 16. Nociceptor Nociceptor arefree nerve endings that sense heat ,mechanical and chemical tissue damage Nociceptive pain is well localized Sharp There is obvious tissue injury or illness ant site Inflamation present Its an physiological pain
- 17. Orofacial Pain classification( OKESON ) Axis 1 (physical conditions) 1 Somatic Pain A.Superficial Somatic Pain a.Cutaneous pain b.Mucogingival B.Deep Somatic Pain a.Muscle pain b.TMJ pain c.Osseous pain d.Periodontal pain 2 Visceral pain a.Pulpal pain b.Vascularpain c. Neurovascular pain d.Visceral mucosal pain e.Glandular ocular auricular pain Axis 2 (psychologic condition) 1.mood disorder 2. Anxiety disorder 3.Somatoform disorder 4.Other Condition – psychologic factor affecting a medical condition
- 22. Components Of Pain FIBRETYPE FUNCTION CONDUCTION VELOCITY (mts/sec) SPIKE DURATION (mili sec) Aα (Myelinated fibers) Proprioception ,somatic motor 30-120 0.4-0.5 Aβ (Myelinated fibers) Touch ,pressure and motor function 30-120 Aγ (Myelinated fibers) Motor to muscle spindle 15-35 Aδ (Myelinated fibers) Pain ,temperature , touch 5-25 B (Myelinated fibers) Preganglionic autonomic fibers 3-15 1.2 C(Unmyelinated fibers) Pain ,temperature , touch and conducts impulses generated by cutaneous receptor 0.7-1.3 2
- 23. Gilron, Ian.(2000). Neural Blockade in the Evaluation and Management of Chronic Pain: An Overview. Pain Research and Management. 5. 93-100. 10.1155/2000/546792.
- 24. FAST PAIN Feltwitin 0.1 sec Sharp ,priciking,acute,electric pain When needle is struck into the skin /electric shock /cuts Not felt in most deeper tissue of the body Transmitted through A pain Fibers SLOW PAIN Felt after a sec or more /maybe minute Burning ,aching ,Throbbing ,Chronic Pain Associated with tissue destruction Can occur in skin and in any deep tissue or organ Result from primitive Type C pain Fibers
- 25.
- 26. Pain Receptors Sensory Receptor At the distal terminals are the afferent [sensory] nerve specialized sensory receptor that respond to physical or chemical stimuli Once these receptor are adequately stimulated ,an impulse is generated in the primary afferent neuron that is carried centrally into the CNS Classified in 3 Group 1. Exteroreceptors 2. Proprioceptors 3. Interorecepters
- 27. EXTERORECEPTORS Stimulated byimmediate external environment Provide information from the skin and mucosa Eg- 1. Merkel’s corpuscles [tactile receptors in the submucosa of tongue] 2. Meissner’s corpuscles tactile receptors in skin 3. Free nerve ending perceive superficial pain and touch
- 28. PROPRIOCEPTORS Provide informationfrom the musculoskeletal structure concerning the position and movement of the body Automatic Functioning Eg- Muscle spindle mechanoreceptors found between skeletal muscle fibers Golgi tendon organ mechanoreceptors in the tendon of muscles signal muscle tension Periodontal mechanoreceptors respond to biomechanical stimuli.
- 29. INTEROCEPTORS Located inand transmit impulse from viscera of the body Eg- Pacinian Corpuscles concerned with perception of pressure Free nerve ending perceive visceral pain and other sensation
- 30. Neural Pain Pathway Sensory input from various stimuli [either external or internal ] is received by specific peripheral receptor called as nociceptors Nocicepters respond as transducers and transmit impulse Perception of pain Found in all parts of body
- 31. External Nociceptors-skin ,cornea and mucosa Internal Nociceptors-Muscles ,joint ,bladder,gut and continuing along GIT Cell bodies of these neuron are located in either the dorsal root ganglia or the trigeminal ganglia Trigeminal Ganglia are specialized nerves for the face ,whereas the dorsal root ganglia associate with the rest of the body.
- 32. Sensory Neuron FIRST ORDERNEURON [POSTERIOR NERVE ROOT GANGLIA] SECOND ORDER NEURON [SUBSTANTIA GELATINOSA] THIRD ORDER NEURON [THALAMIC NUCLEUS, RETICULAR FORMATION , TECTUM ,GREY MATTER,SOMATOSENSORY]
- 33. First Order Neuron Each sensory receptor is attached to a first order primary afferent neuron that carries the impulse to the CNS The axon of these first order neuron are found to have varying thickness Larger fibers conduct impulse more rapidly than smaller fibers
- 34. Second Order Neuron The primary afferent neuron carries impulse into the CNS and synapse with the second order neuron This second order neuron is sometimes called transmission neuron since it transfers the impulse on to the higher centers. The synapse of the primary afferent and the second order neuron occurs in the dorsal horn of the spinal cord
- 35. Third Order Neuron Cell Bodies of third order neuron of the nociception relaying pathway are housed in the ventro- posterior lateral ,the ventro –posterior inferior and intralaminar thalamic nuclei Third order neuron fibers from the thalamus relay thermal sensory information to the somesthetic cortex.
- 36. Peripheral mechanism ofinjury induced pain[NEUROPHYSIOLOGY OF PAIN ] TRANSDUCTON TRANSMISSION PERCEPTION MODULATION
- 37. TRANSDUCTION 1-Activation of nociceptor Intense thermal and mechanical stimuli ,noxious chemicals , noxious cold 2-Stimulation of inflammatory mediators Damaged tissue release bradykinin ,potassium, histamine ,serotonin and arachidonic acid Arachidonic acid produce prostaglandins and leukotrienes.
- 38. Bradykinin +Leukotriene +Prostaglandins[PG stimulates nociceptors directly] Increases plasma extravasation Edema Leukotriene stimulates nociceptors indirectly by PMNs Release Chemical mediators Stimulates nociceptor
- 39. BK causessympathetic nerves terminal to release PG thus stimulates nociceptor. Sympathetic nerve terminal release another PG in response to its own Neurotransmitter norepinephrine Such ongoing inflammatory state cause physiologic sensitization of nociceptors thus generating a response even to a non –painful stimuli and exaggerated response to noxious stimuli
- 40. TRANSMISSION Process bywhich peripheral nociceptive information is relayed to CNS First order neuron synapses with the secondary order neuron from where impulse is csrried to higher center of brain Repeated or intense C fibers activation brings specific changes on N- methyl-d aspartate receptors resulting in central sensitization ,thus ,response of second order neuron increases as well as size of the receptive field also increases.
- 41. PERCEPTION It isthe subjective experience of pain It is the sum of complex activities in CNS that may shape the character and intensity of pain perceived and ascribe meaning to pain.
- 42. MODULATION It isthe mechanism by which transmission of impulse to brain is reduced a) Descending inhibitory system that originates supraspinally b) Periaqueductal gray c) Anucleus raphe magnus d) Nucleus tractus solitarius e) Locus ceruleus /subceruleus f) Endogenous opioid peptide
- 43. Pain Pathway Pain [Receptor] Free nerveending Posterior nerve root Ganglion [First order neuron ] Fibers from lateral spinothalamic tract [Second order neuron ] Ventral posterolateral nucleus of thalamus ,reticular formation and midbrain [Third order neuron] Sensory Cortex [Center]
- 44. Theories Of Pain 1.Convergence theory 2. Facilitation Theory 3. Gate Control Theory
- 45. Convergence theory Bothsomatic and visceral afferent fibers converge upon second order neuron Somatic fibers conduct impulses more frequent. Visceral pain felt as somatic pain because brain is familiar with somatic regions.
- 46. Facilitation Theory Visceraland somatic fibers join at adjoining spinothalamic neuron i.e second order neuron Activation of spinothalamic neuron occurs due to strong impulses resulting in impulses passing through spinothalamic pathway This results in misinterpretation in location of pain
- 47. Gate Control Theory Proposed by Ronald Melzack and Pat-rick wall The pain stimuli transmitted by afferent fibers are blocked by Gate mechanism located in posterior gray horn of spinal cord .If gate is OPENED ,pain is felt .If gate is CLOSED pain is suppressed. Due to this ,there is relief of pain through rubbing ,massaging or application of ice pack ,acupuncture and electrical analgesia.
- 48. 1. When painstimulus is applied on any part of body ,beside pain receptor,then the receptors of other sensation are also stimulated 2. When all these impulses reach the spinal cord through posterior nerve root,then the fibers of touch sensation send collaterals t the neuron of pain pathway 3. Impulses of touch sensation to passing to these collaterals inhibit the release of glutamate and substance –P from pain fibers 4. This closes the gate and pain sensation get blocked.
- 49. Visceral Pain Theyare dull and diffuse ,poorly localized and associated with symptoms like nausea and reffered to other area Stimuli for visceral pain –Ischemia ,Obstruction ,Spasm ,Chemical Stimuli.
- 50. Referred Pain Painfelt in a part of the body other than its actual source Pain at diaphragm felt at tip and over shoulder Pain in maxillary sinus felt at nearby teeth A tooth abscess can cause jaw bone pain.
- 51.
- 52. 1 -Exposure ofdentinal tubules causes toothache and other non noxious sensation. 2 -Both Aδ And C fibers response to stimuli in dentine 3 -Transmission of stimuli across dentine ,mediated by movement of fluid in dentinal tubules.
- 53. 4 -Fibers terminateat medullary dorsal horn and synapse and also at trigeminal sensory nucleus 5 -From Trigeminal nucleus send to thalamus and then to sensory cortex 6 -Pulpal innervation are capable of regenerating and reinnervating
- 54. Determinants of painfulexperience during dental treatment Pain occurs due to invasive procedures like extraction and surgeries or non invasive procedures .With regards to children ,studies have shown that dentists do not believe in pain referred by child and tend not to use available method to control pain Anxiety is determinant for pain during dental care and pain is related to LA procedures .There are evidence that dentist attitude are determinants for pain.
- 55.
- 56.
- 57. The sensory functionsare affected by lesion in sensory pathway or other nervous disorders Anesthesia – loss of sensation . Hyperesthesia –increase sensitivity to sensory stimuli. Hypoesthesia –decrease sensitivity to sensory stimuli. Hemiesthesia - loss of sensation to one part of body. Paresthesia – abnormal sensation.
- 58. Dissociated anesthesia-loss of some sensation with loss of consciousness produced by anesthetic agents General Anesthesia –loss of all sensation with loss of consciousness produced by anesthetic agents Local anesthesia –loss of sensation in restricted area of body Tactile Anesthesia – loss of tactile sensation
- 59. Hyperalgesia –increasein sensitivity to pain Paralgesia – abnormal pain sensation Thermic anesthesia –loss of thermal sensation Analgesia – loss of pain sensation .
- 60.
- 61. HERPES ZOSTER Herpeszoster is a viral infection affecting dorsal root ganglion .Results in severe pain towards the ganglion. Pain can be mild to extreme in the affected dermatome ,with sensation that are often described as stinging ,tingling ,aching , numbing or throbbing. Symptoms- 1. Burning pain 2. Itching 3. Hyperesthesia 4. Paresthesia Bader MS. Herpes zoster: diagnostic, therapeutic, and preventive approaches. Postgrad Med. 2013 Sep;125(5):78-91. doi: 10.3810/pgm.2013.09.2703. PMID: 24113666.
- 62. Treatment Analgesics -Mild tomoderate –Topical Lotion containg CALAMINE -Severe Pain –Opiod medication such as morphine -Once the lesion have crusted over,Capsaicin cream can be used -Topical Lidocaine and Nerve Block may also reduce pain -Administrating Gabapentine along with Antiviral May offer Relif of post Herpetic Neuralgia (PHN)
- 63. Antiviral -These drugreduce the severity and duration but do not prevent Post herpetic Neuralgia -Acylovir Has been Standard Treatment ,Can be replaced by new drug Valaciclovir and Famciclovir.
- 64. TRIGEMINAL NEURALGIA • TrigeminalNeuralgia is a Chronic Pain disorder that affects the 5th C.N • Trigeminal neuralgia (TN) is characterised by unilateral, intense, touch-evoked, stabbing paroxysmal pain. It typically affects the second and third trigeminal branch. • Trigeminal neuralgia can be either idiopathic or secondary to multiple sclerosis or a space-occupying lesion. • Types • -Typical • -Atypical Maarbjerg S, Di Stefano G, Bendtsen L, Cruccu G. Trigeminal neuralgia - diagnosis and treatment. Cephalalgia. 2017 Jun;37(7):648-657. doi: 10.1177/0333102416687280. Epub 2017 Jan 11. PMID: 28076964.
- 65. Treatment Anticonvulsant carbamazepineis first line drug Baclofen ,lamotrigine,oxcarbazepine ,phenytoin, gabapentin and pregabalin is second line of drug Antidepressant medication such as Amitriptyline have shown good efficacy ,especially with pregabalin
- 66. Non destructiveSurgery Microvascular decompression this involves a small incision behind the ear and some bone is removed from that area and incision through meninges are made to expose the nerve .Any vascular compressions of the nerve are carefully moved and a sponge –like pad placed between the compression and the nerve
- 67. Destructive Surgery •Glycerol Injection deposition of glycerol at this point cause damage to the nerve to hinder pain signals • Radiofrequency –application of a heated needle to damage the nerve • Sterotactic Radiosurgery [Gamma knife surgery] – is a form of radiation therapy that focuses high power energy on a small area of body
- 68. Conclusion Pain caninduce physiological and anatomical changes within the nervous system .The complexity of pain transmission means there are many pharmologica targets and multimodel theraphy is required to optimize pain control.
- 69. References Article Maarbjerg S,Di Stefano G, Bendtsen L, Cruccu G. Trigeminal neuralgia - diagnosis and treatment. Cephalalgia. 2017 Jun;37(7):648-657. doi: 10.1177/0333102416687280. Epub 2017 Jan 11. PMID: 28076964. Bader MS. Herpes zoster: diagnostic, therapeutic, and preventive approaches. Postgrad Med. 2013 Sep;125(5):78-91. doi: 10.3810/pgm.2013.09.2703. PMID: 24113666. Costa, Ruth & Ribeiro, Suelen & Cabral, Etenildo. (2012). Determinants of painful experience during dental treatment. Revista Dor. 13. 365-370. 10.1590/S1806-00132012000400011. Ryan Moffat, Colin P. Rae,Anatomy, physiology and pharmacology of pain, Anaesthesia & Intensive Care Medicine,Volume 12, Issue 1,2011,Pages 12-15,ISSN 1472-0299 Case report study on Brown Sequard syndrome –Ponachi et al Neurology Asia 2007;12;65-67. Gilron, Ian. (2000). Neural Blockade in the Evaluation and Management of Chronic Pain: An Overview. Pain Research and Management. 5. 93-100. 10.1155/2000/546792. Consice MEDICAL PHYSIOLOGY –Chaudhuri Monheim’s Local Anesthesia and pain control in dental practice Essential Of medical physiology –K.Sembulingam and Prema Sembulingam.
- 70.