Lower Back Injury: Isaiah Delgado, wrestler, began participating in a fitness and nutrition program at Push-as-RX in order to improve his performance in his physical activities. When he suffered a lower back sports injury, Isaiah Delgado once again came to Push for assistance, except this time, the trainers enrolled him in a rehabilitation program to help him return-to-play as soon as possible. Isaiah Delgado describes Push-as-Rx as a lifestyle and he recommends Push to anyone looking for the right type of support when it comes to recovery and increased performance.
Lower Back Injury And Chiropractic Care
Sports Therapy is an element of healthcare that’s specifically concerned with the prevention of injury and the rehabilitation of the individual back to optimum levels of practical, occupational and sports specific fitness, regardless of age and capacity. It utilizes the fundamentals of sport and exercise sciences incorporating behavioral and physiological processes to prepare the player for training, competition and where applicable, work. A variety of healthcare professionals are able to provide this type of treatment method.
We are blessed to present to you�El Paso�s Premier Wellness & Injury Care Clinic.
As El Paso�s Chiropractic Rehabilitation Clinic & Integrated Medicine Center,�we passionately are focused treating patients after frustrating injuries and chronic pain syndromes. We focus on improving your ability through flexibility, mobility and agility programs tailored for all age groups and disabilities.
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The aging process can usher in a variety of conditions and health issues that are confined (mostly) to the elderly. Chronic pain, arthritis, loss of mobility, and other issues can occur as a person get older, but senior citizens are finding that chiropractic provides some great benefits for the older demographic.
Senior Citizens
Better Range Of Motion
Regular chiropractic care has been shown to increase spinal range of motion as well as in the extremities. Limited range of motion can occur due to age or inactivity � sometimes a combination of the two.
Having the ability to move easier has many great benefits. It allows seniors to more actively engage with their environment. They can get on their hands and knees to work in the garden, bend down to pick up grandchildren, and improve leisure activities like golfing. Increased range of motion is one of the most common (and appreciated!) benefits of chiropractic treatment.
Decreased Degeneration Of Joints
When the spine is misaligned it can lead to other parts of the body becoming misaligned as well. This can lead to unusual and unnatural wearing of the joints. Over time, the joints can become worn down, painful, and cause difficulty in mobility and flexibility.
Chiropractic care is a very effective treatment for decreasing the degeneration of the spine and even other joints. When the body is in proper alignment it no longer has to adapt through postural compensation. This reduces stress on the spine and joints while relieving pain and restoring mobility.
Pain Relief
Chiropractic has long been recognized for its effectiveness in providing drug free pain relief for everything from back pain to headaches to arthritis. While pain medication and anti-inflammatory drugs only suppress the symptoms, chiropractic addresses the root of the problem.
Spinal alignments and other chiropractic techniques help to relieve pain for a variety of issues, not just back and neck pain. What�s more, chiropractic does not have the undesirable, sometimes dangerous side effects that drugs can.
Overall Better Health & Wellbeing
Proper spinal alignment can greatly benefit a person�s health, wellbeing, and even their mood. It allows them to become more active so they get exercise. They sleep better and have more energy.
An aligned spine also lets them more fully engage with their family, friends, and the world. They can get out and do things they were once unable to do and when they are active and happier the entire body benefits.
Improved Coordination & Balance
The aging process can have a significant impact on a person�s balance and coordination. This can have a variety of causes including degenerative changes to the spine, typically in the neck area. Injury to this area is another culprit.
There are special receptors that reside along the cervical spine in the rear of the joints. These receptors work to send vital messages to the brain regarding coordination and balance. When the spine and especially the neck are out of alignment, it can hinder how these receptors send and receive messages to the brain. The result is a condition called loss of proprioception, or sense of body awareness.
As the condition progresses, the patient relies on vision to determine the location of their feet, legs, and other limbs. The worse it gets, the less able the patient is in compensating and can become prone to falling.
Injuries from falling are one of the most common reasons elderly people visit emergency departments each year. Chiropractic can help realign the neck and spine, allowing the messages to move much easier, thus restoring balance and coordination.
Prevents Seniors From Being Confined To Nursing Homes
Senior citizens who are regular chiropractic patients are more likely to engage in exercise that is more strenuous. They are more active, have fewer injuries, and are basically happier and more positive.
The more active and mobile senior citizens are, the less likely they are to be placed in a nursing home due to medical conditions or the �typical� aging issues. Simply put, chiropractic for seniors changes the way many people look at aging � and places it in a much more positive, active light.
Injury Medical Clinic: Elderly & Geriatric Fitness
Most, if not all, ailments of the body trigger pain. Pain is interpreted and sensed in the brain. Pain is modulated by two key types of drugs which operate on the brain: analgesics and anesthetics. The term analgesic refers to a medication that relieves pain without loss of consciousness. The expression central anesthesia refers to a medication that depresses the CNS. It’s distinguished by the lack of all perception of sensory modalities, for instance, loss of consciousness without loss of critical functions.
Opiate Analgesia (OA)
The most successful clinically used drugs for producing temporary analgesia and relief from pain are the opioid family, which includes morphine, and heroin. There are currently no additional powerful pain therapeutic options to opiates. Several side effects caused by opiate use include tolerance and drug dependence or addiction. In general, these drugs modulate the incoming pain information in the spine and central nervous system, in addition to relieve pain temporarily, and can also be called opiate producing analgesia (OA). Opiate antagonist is a drug that antagonizes the opioid effects, such as naloxone or maltroxone, etc.. They are competitive antagonists of opiate receptors. However, the brain has a neuronal circuit and endogenous substances which modulate pain.
Endogenous Opioids
Opioidergic neurotransmission is located throughout the brain and spinal cord and is believed to influence many functions of the central nervous system, or CNS, such as nociception, cardiovascular functions, thermoregulation, respiration, neuroendocrine functions, neuroimmune functions, food consumption, sexual activity, competitive locomotor behaviour as well as memory and learning. Opioids exert marked effects on mood and motivation and produce a sense of euphoria.
Three classes of opioid receptors are identified: ?-mu, ?-delta and ?-kappa. All 3 classes are widely dispersed in the brain. The genes encoding each one of these have been cloned and found to function as members of the G protein receptors. Moreover, three major types of endogenous opioid peptides that interact with the above opiate receptors have been recognized in the central nervous system, including, ?-endorphins, enkephalins and the dynorphins. These 3 opioid peptides are derived from a large protein receptor by three different genes, such as the proopiomelanocortin, or POMC, gene, the proenkephalin gene and the prodynorphin gene.�The opioid peptides modulate nociceptive input in two ways: first, they block neurotransmitter release by inhibiting Ca2+ influx into the presynaptic terminal, or second, they open potassium channels, which hyperpolarizes neurons and inhibits spike activity. They act on various receptors within the brain and spinal cord.
Enkephalins are considered the putative ligands for the ? receptors, ? endorphins for its ?-receptors, and dynorphins for the ? receptors. The various types of opioid receptors are distributed differently within the peripheral and central nervous system, or CNS. There’s evidence for functional differences in these receptors in various structures. This explains why many undesirable side effects occur after opiate treatments. For instance, mu (?) receptors are widespread in the brain stem parabrachial nuclei, where a respiratory center and inhibition of these neurons may cause what’s known as respiratory depression.
Central or peripheral terminals of nociceptive afferent fibers feature opiate receptors in which exogenous and endogenous opioids could act to modulate the capability to transmit nociceptive information. Additionally, high densities of opiate receptors are found in periaqueductal gray, or PAG, nucleus raphe magnus, or NRM, and dorsal raphe, or DR, from the rostral ventral medulla, in the spinal cord, caudate nucleus, or CN, septal nucleus, hypothalamus, habenula and hippocampus.�Systemically administered opioids at analgesic dosages activate spinal and supraspinal mechanisms via ?, ?, and ? type opioid receptors and regulate pain signals to modulate symptoms.
Neuronal Circuits and Pain Modulation
For many decades it was suggested that somewhere in the central nervous system there is a circuit which can modulate incoming pain details. The gate control theory and the ascending/descending pain transmission system are two suggestions of such a circuit. Below, we will discuss both in further detail.
Gate Control Theory
The initial pain modulatory mechanism known as the gate control theory, has been proposed by Melzack and Wall in the mid 1960’s. The notion of the gate control theory is that non-painful input closes the gates to painful input, which results in avoidance of the pain sensation from travel into the CNS, for example, non-noxious input, or stimulation, suppresses pain.
The theory implies that collaterals of the large sensory fibers carrying cutaneous sensory input activate inhibitory interneurons, which inhibit and regulate pain transmission data carried from the pain fibers. Non-noxious input inhibits pain, or sensory input, and closes the gate to noxious input. The gate control theory demonstrates that in the spinal cord level, non-noxious stimulation will create presynaptic inhibition on dorsal root nociceptor fibers that synapse on nociceptors spinal neurons (T). This presynaptic inhibition will also prevent incoming noxious information from reaching the CNS, for example, it will shut the gate to incoming toxic information.
The gate control theory was the rationale for the idea behind the production and utilization of the transcutaneous electrical nerve stimulation, or TENS, for pain relief. In order to be effective, the TENS unit generates two different present frequencies below the pain threshold that can be taken by the patient. This process has found a degree of achievement in chronic pain treatment.
Evidence for an inherent analgesia system was found by intracranial electrical stimulation of certain discrete brain regions. These areas would be the periaqueductal gray, or PAG, and nucleus raphe magnus, or NRM, dorsal raphe, or DR, caudate nucleus, or CN, septal nucleus, or Spt, along with other nuclei. Such stimulation or sensory signals, inhibits pain, making analgesia without behavioral suppression, while the touch, temperature and pressure sensation stays intact. According to research studies, SPA, or stimulation produced analgesia, is more pronounced and continues for a longer period of time after stimulation in humans than in experimental animals. Additionally, during SPA, the subjects, however, still respond to nonpainful stimulation like temperature and touch within the circumscribed region of analgesia. The most effective CNS, or central nervous system regions for SPA to occur, would be in the PAG and the raphe nuclei, or RN.
Electrical stimulation of PAG or NRM inhibits spinal thalamic cells, or spinal neurons that project monosynaptically to the thalamus, in laminae I, II and V to ensure the noxious information from the nociceptors which are ultimately modulated in the level of the spinal cord. Furthermore, PAG has neuronal connections to the nucleus raphe magnus, or NRM.
The activity of the PAG most likely occurs by activation of the descending pathway from NRM and likely also by activation of ascending connections acting on greater subcortical levels of the CNS. In addition, electric stimulation of PAG or NRM produces behavioral analgesia, or stimulation produced analgesia. Stimulation produced analgesia, or SPA causes the release of endorphins which can be blocked by the opiate antagonist naloxone.
During PAG and/or RN stimulation, serotonin, also medically referred to as 5-HT, can also be discharged from ascending and descending axons from subcortical nuclei, in spinal trigeminal nuclei and in the spinal cord. This release of 5-HT modulates and regulates pain transmission by inhibiting or blocking incoming neural action. Depletion of 5-HT by electrical lesion of the raphe nuclei or with a neurotoxic lesion made by local injection of a chemical agent such as parachlorophenylalanine, or PCPA, results in blocking the power of opiate, both intracranial and systemic, as well as that of electrical stimulation in order to produce analgesia.
To confirm if the electric stimulation produced analgesia via the release of opiate and dopamine, then the region is locally microinjected with morphine or 5-HT. All these microinjections ultimately create analgesia. These processes also provide a way of identifying brain areas related to pain suppression and assist to produce a map of pain centers. The most effective way of producing opiate analgesia, or OA, is by intracerebral injection of morphine into the PAG.
The PAG and RN as well as other brain structures in which analgesia is produced, are also rich in opiate receptors. Intracerebral opioid administration produced analgesia and SPA can be blocked by systemic or from local microinjections of naloxone, the morphine antagonist, into the PAG or RN. For that reason, it’s been suggested that the two, both OA and SPA, operate by a frequent mechanism.
If OA and SPA behave through the same intrinsic system, then the hypothesis that opiates activate a pain-suppression mechanism is much more likely. As a matter of fact, current evidence suggests that microinjections of an opiate into the PAG activate an efferent brainstem system which inhibits pain transmission at segmental spinal cord levels. These observations imply that analgesia elicited from the periaqueductal gray, or PAG, demands a descending pathway into the spinal cord.
Dr. Alex Jimenez’s Insight
Pain modulation occurs through the process of electrical brain stimulation which occurs due to the activation of descending inhibitory fibers, which regulate or inhibit the input and output of certain neurons. What has been described as opioid and serotonergic antagonists, is believed to reverse both local opiate analgesia and brain-stimuli generated analgesia. The sensory signals or impulses in the central nervous system are ultimately controlled by both ascending and descending inhibitory systems, utilizing endogenous opioids or other endogenous substances, such as serotonin as inhibitory mediators. Pain is a complex perception which can also be influenced by a variety of other factors, including emotional state.
Mechanisms of Pain Modulation
Ascending and Descending Pain Suppression Mechanism
The primary ascending pain fibers, such as the A ? and C fibers, reach the dorsal horn of the spinal cord from peripheral nerve areas in order to innervate the nociceptor neurons in Rexed laminae I & II. Cells from Rexed lamina II make synaptic connections in Rexed layers IV to VII. Cells, particularly within laminae I and VII of the dorsal horn, give rise to ascending spinothalamic tracts. In the spinal level, opiate receptors are located in the presynaptic endings of their nocineurons and in the interneural level layers IV to VII from the dorsal horn.
Activation of opiate receptors at the interneuronal level produces hyperpolarization of the neurons, which lead to the the inhibition of activation as well as the release of substance P, a neurotransmitter involved in pain transmission, thus preventing pain transmission. The circuit which consists of the periaqueductal gray, or PAG, matter in the upper brain stem, the locus coeruleus, or LC, the nucleus raphe magnus, or the NRM, and the nucleus reticularis gigantocellularis, or Rgc,� leads to the descending pain suppression pathway, which inhibits incoming pain data at the spinal cord level.
As stated before, opioids interact with the opiate receptors in distinct central nervous system levels. These opiate receptors are the normal target regions for hormones and endogenous opiates, such as the endorphins and enkephalins. Due to binding at the receptor in subcortical websites, secondary changes which result in some change in the electrophysiological properties of the neurons and regulation of their ascending pain information.
What activates the PAG to exert its consequences? It was discovered that noxious stimulation triggers neurons in the nucleus reticularis gigantocellularis, or RGC. The nucleus Rgc innervates both PAG and NRM. The PAG sends axons into the NRM, and nerves in the NRM send their axons to the spinal cord. Additionally, bilateral dorsolateral funiculus, or DLF, lesions, referred to as DLFX, block the analgesia produced by both electrical stimulation and by microinjection of opiates directly into the PAG and NRM, but they just attenuate the systemic analgesic effects of opiates. These observations support the hypothesis that discrete descending pathways from the DLF are necessary for both OA and SPA.
The DLF is comprised of fibers originating from several brainstem nuclei, which can be serotonergic, or 5-HT, from nerves located inside the nucleus raphe magnus, or NRM; dopaminergic neurons originating from ventral tegmental area, or VTA, and adrenergic neurons originating from the locus coeruleus, or LC. These descending fibers suppress noxious input in the nociceptive spinal cord neurons in laminae I, II, and V.
Opiate receptors have also been discovered in the dorsal horn of the spinal cord, chiefly in Rexed laminae I, II, and V, and such spinal opiate receptors mediate inhibitory effects on dorsal horn neurons transmitting nociceptive information. The action of morphine seems to be exerted equally in the spinal cord and brainstem nuclei, including the PAG and NRM. Systemic morphine acts on both brain stem and spinal cord opiate receptors to produce analgesia. Morphine binds the brainstem opiate receptors, which triggers the brainstem descending serotonergic pathway into the spinal cord as well as the DLF, and these have an opioid-mediated synapse at the level of the spinal cord.
This observation demonstrates that noxious stimuli, instead of non-noxious stimulus, determine the gate control theory, which are critical for the activation of the descending pain modulation circuit where pain inhibits pain via the descending DLF pathway. In addition, there are ascending connections in the PAG and the raphe nuclei into the PF-CM complex. These thalamic regions are a part of the ascending pain modulation at the diencephalon degree.
Stress Induced Analgesia (SIA)
Analgesia may be produced in certain stressful circumstances. Exposure to many different stressful or painful events generates an analgesic response. This phenomenon is known as stress induced analgesia, or SIA. Stress induced analgesia has been believed to give insight into the physiological and psychological factors that trigger endogenous pain control and opiate systems. By way of instance, soldiers injured in battle or athletes hurt in sports sometimes report that they don’t feel pain or discomfort during the battle or game, nevertheless, they will go through the pain afterwards once the specific situation has stopped. It’s been demonstrated in animals that electrical shocks cause stress-induced analgesia. Based on these experiments, it is assumed that the pressure the soldiers and the athletes experienced suppressed the pain which they would later experience.
It’s believed that endogenous opiates are produced in response to stress and inhibit pain by triggering the midbrain descending system. Furthermore, some SIA exhibited cross tolerance with opiate analgesia, which indicates that this SIA is mediated via opiate receptors. Experiments using different parameters of electrical shock stimulation demonstrate such stress induced analgesia and some of those anxieties that produce analgesia could be blocked by the opioid antagonist naloxone, whereas others were not blocked by naloxone. In conclusion, these observations lead to the decision that both opiate and non-opiate forms of SIA exist.
Somatovisceral Reflex
The somatovisceral reflex is a reflex in which visceral functions are activated or inhibited by somatic sensory stimulation. In experimental animals, both noxious and innocuous stimulation of somatic afferents are proven to evoke reflex changes in sympathetic efferent activity and, consequently, effector organ function. These phenomena have been shown in such regions as the gastrointestinal tract, urinary tract, adrenal medulla, lymphatic cells, heart and vessels of the brain and peripheral nerves.
Most frequently, incisions are elicited experimentally by stimulation of cutaneous afferents, even though some work has also been conducted on muscle and articular afferents, including those of spinal cells. The ultimate responses will represent the integration of multiple tonic and reflex influences and might exhibit laterality and segmental trends as well as variable excitability in line with the afferents involved. Given the complexity and multiplicity of mechanisms involved in the last expression of the reflex response, attempts to extrapolate to clinical situations should most likely be conducted in favor of further systematic physiological studies.
The scope of our information is limited to chiropractic as well as to spinal injuries and conditions. To discuss the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .
Curated by Dr. Alex Jimenez
Additional Topics: Sciatica
Sciatica is medically referred to as a collection of symptoms, rather than a single injury and/or condition. Symptoms of sciatic nerve pain, or sciatica, can vary in frequency and intensity, however, it is most commonly described as a sudden, sharp (knife-like) or electrical pain that radiates from the low back down the buttocks, hips, thighs and legs into the foot. Other symptoms of sciatica may include, tingling or burning sensations, numbness and weakness along the length of the sciatic nerve. Sciatica most frequently affects individuals between the ages of 30 and 50 years. It may often develop as a result of the degeneration of the spine due to age, however, the compression and irritation of the sciatic nerve caused by a bulging or herniated disc, among other spinal health issues, may also cause sciatic nerve pain.
Neurophysiology: There are two ways that nociceptive information reaches the central nervous system. One is the neospinothalamic tract for quick pain and two is the paleospinothalamic tract for slow pain that increases.
Neurophysiology Of Pain Part II
Intensity, Location & Quality of Pain…
… involve Spinothalamic and Trigeminal Pathways
The trigeminal pathway brings information from the face area.
The spinothalamic pathway brings information from the rest of the body.
Both these pathways project to the sensory cortex, which also receives information on innocuous stimuli such as touch, pressure and warmth via a separate pathway.
2 Pain Transmission Pathways For Location Intensity Quality
There is difference between the objective and subjective aspects of injury and pain.
Despite similar injury, people can differ in how much pain they feel.
Depending on the context, pain may not be felt despite injury, e.g. battlefield injury, during intense sports.
This suggests that there is a physiological mechanism that controls the transmission of nociceptive signals to the brain or modifies the interpretation of pain.
The pain control system can also explain the placebo effect.
Pain Modulation Pathway
Nerve signals are sent form the somatic sensory cortex and hypothalamus to the periaqueductal gray matter (PAG).
PAG sends signals to the parabrachial nucleus, medullary reticular formation, locus coeruleus, and Raphe neulei.
These in turn can control the in the transmission of nociceptive signals from the spinal cord to the brain.
This involves different involves different neurotransmitters.
Endogenous Opioids
Internally produced molecules with opioid-like action which regulate transmission of nociceptive signals.
Three classes of these molecules have been identified. All are peptide molecules
Enkephalins
Endorphins
Dynorphins
Despite these being powerful, endogenous modifiers of nociceptive signals, it has been difficult to produce and administer them in a way than can used in clinical practice.
Location Of Nerve Cells With Endogenous Opioid Receptors
In the spinal cord, endogenous opioids can prevent transmission between 1st order nerve cells (bringing signals from the periphery) and 2nd order spinal nerve cells that transmit the signals to the brain.
Also can prevent the increased synaptic efficiency, which plays a role in hyperalgesia.
Knowing the molecules involved in the �inflammatory soup� and how they are synthesized provides possible targets for pain reduction.
e.g. prostaglandins are produced by the COX enzyme. The activity of this enzyme is blocked by non-steroidal anti- inflammatory drugs (NSAIDs) such as ibuprofen, diclofenac.
Allodynia
A condition when normally non- painful stimuli cause pain, e.g., touch, light pressure, cold.
Involves changes in the synaptic sensitivity of the nociceptive neurons in the spinal cord (central sensitization).
Drugs such as ketamine, block NMDA receptors and so reduce transmisison of the nociceptive stimuli.
Gate Control Theory of Pain
Mother says to child, �Come I will rub the area which is painful and this will make it feel better.�
After stubbing a toe, we instinctively rub the area; this reduces the sensation of pain.
Ronald Melzack and Patrick Wall in 1962 provided an possible explanation for this effect.
Ascending Tracts | Pain Modulation: Gate Control Theory
Gate Theory
Rubbing the area that hurts stimulates receptors of innocuous stimuli like touch, pressure and vibration.
These mechano-receptors send signals along the A? nerve fibers that:
(1) stimulate spinal nerves (inhibitory inter-neurons) that in turn inhibit signaling in the 2nd order neurons (projection neuron) and (2) directly inhibit the 2nd order neuron to reduce or stop pain signal from being sent to the brain
Transcutaneous Nerve Stimulation (TENS) is based on the Gate Control Theory. Nerves of the innocuous sensory system are stimulated and they in turn, inhibit transmission of nociceptive stimuli in the spinal cord.
Abnormalities Of Pain System
Phantom Pain
Patients with amputation often have burning or tingling pain in the body part removed.
One possible cause is that nerve fibers at the stump are stimulated and the brain interprets the signals as originating in the amputated portion.
The other is the rearrangement within the cortical areas so that area say for the hand now responds to signals from other parts of the body but still interprets them as coming for the amputated hand.
Peripheral Sensitization
Peripheral sensitization represents a reduction in the threshold and/or an increase in magnitude of responsiveness at the peripheral ends of sensory nerve fibers.
This occurs in response to chemical mediators released by nociceptors and non-neuronal cells (e.g. mast cells, basophils, platelets, macrophages, neutrophils, endothelial cells, keratinocytes and fibroblasts) at the site of tissue injury or inflammation.
Basically, it is an increased sensitivity to an afferent nerve stimuli.
Central Sensitization
Peripheral & Central Sensitisation
A condition of the nervous sytem that is associated with the development and maintenance of chronic pain.
Known as �wind-up� or persistent high reactivity.
�Plastiticity in pain pathways� or the persistence of pain even after an injury has healed.
Is this negative or positive plasticity?
Central Sensitization & C Fibers
Two Main Characteristics Of Central Sensitization:
� Allodynia � occurs when a person experiences pain with things that are normally not painful, ie, soft touch causes pain.
� Hyperalgesia � occurs when a stimulus that is typically painful is perceived as more painful that it should be, ie, a simple bump.
Both are due to hyperreactivity of the nervous system.
Neurophysiology of pain: Pain�defined is the unpleasant sensation that accompanies injury or near injury to tissues, though it can also occur in the absence of such damage if the nociception system is not functioning. Nociception means the system that carries pain signals of injury from the tissues. This is the physiological incident that comes with pain.
Neurophysiology Of Pain
Objectives
Basics of the nervous system
Synaptic function
Nerve impulses
Transduction of peripheral painful stimuli
Central pathways
Central Sensitization
PeripheralSensitization
Control or modulation of pain signals
Pathophysiology of pain signaling pathway
Definition Of Pain
“Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”.
It is important to know the basic structure of the nervous system.
This will help in:
� Understanding the mechanism by which nociceptive signals are produced.
� Know the different regions of the nervous system involved in processing these signals.
� Learn how the different medications and treatment for pain management work.
Nervous System
Central nervous system (CNS)
Brain and Spinal Cord
Peripheral Nervous System (PNS)
Nerve fibers go to all parts of the body.
Send signals to the different tissues and send signals back to the CNS.
Nerve Cells
The nervous system is made up of nerve cells which send long processes (axons) to make contact with other cells.
Nerve Cell-To-Nerve Cell Communication
Nerve cells communicate with other cells by releasing a chemical from the nerve endings � Neurotransmitters
Basic Steps In Synaptic Transmission
Synaptic Transmission
Steps in the passage of signal from one nerve cell to other.
Drugs are used to block the transmission of signals from one nerve cell to other.
These drugs can effect:
Ca2+ ion channel to prevent Ca2+ inflow which is essential for neurotransmitter (NT) release, e.g., the action of gabapentin.
Release of NT.
Prevent NT from binding to its receptor so stop further transmission of the signal.
Electrical Impulse
Signals move along a nerve process (axon) as a wave of membrane depolarization called the Action Potential.
The inside of all nerve cells has a negative electrical potential of around � 60 mV.
When stimulated this negative electrical potential becomes positive and then negative again in milliseconds.
The action potential moves along the nerve process (axon) to the nerve ending where it cause release of NT.
Action Potential
When there is no stimulation the membrane potential is at its Resting Potential.
When stimulated, channels in the nerve membrane open allowing the flow of sodium ions (Na+) or calcium ions (Ca2+) into the nerve or cell. This makes the inside less negative and in fact positive -the peak of the action potential (+40 mV).
These channels than close and by the opening of K+ channels the membrane potential returns to its resting level.
Stopping Action Potentials To Stop Nociceptive Stimuli
Nociceptive stimuli are those that will create a sensation of pain after they are processed in the CNS.
Nociceptive signals can be prevented from reaching the CNS by blocking the action of the channels that control the movement of ions across the nerve membrane.
A number of anesthetic agents stop Na+ channel from working and hence stop the generation of actions potentials and transmission of signals to the CNS.
Sensory Systems
The sensory system that can be divided into two divisions:
A Sensory System that transmits innocuous stimuli such as touch, pressure, warmth.
A System that transmits stimuli that indicate that tissues have been damaged = nociceptive .
These two systems have different receptors and pathways in the PNS & CNS
Nociceptors are free nerve endings that respond to stimuli that can cause tissue damage or when tissue damage has taken place.
Present in membrane of free nerve endings are receptors (protein molecules) whose activity changes in the presence of painful stimuli.
(Note the use of the same term receptor is used for cell or organs or molecules that involved in transduction of a stimuli.)
Transduction
Transduction is the process of converting the stimuli into a nerve impulse.
For this to occur the flow of ions across the nerve membrane has to change to allow entry of either Na+ or Ca2+ ions to cause depolarization of the membrane potential.
This involves a receptor molecule that either directly or indirectly opens the ion channels.
Chemical Agents…
… which can cause the membrane potential at the free nerve ending (nociceptor) to produce an action potential.
Many stimuli � mechanical, chemical and thermal � give rise to painful sensation making transduction a complex process.
Recently receptor molecules have been identified�� Transient Receptor Potential (TRP) channels � that respond to a number of strong stimuli.
TRP receptors are also involved in transmitting the burning sensation of chili pepper.
In time, drugs that act on these receptors will be developed to control pain.
Different TRP Channels
Capsasin, the active ingredient in chili pepper, is used in patches for relief of pain.
Menthol and peppermint gels are used to relieve muscle pain.
Motor Output & Sensory Input To Spinal Cord
Sensory nerves have their cell body outside the spinal cord in the dorsal root ganglia ( = 1st order neurons).
One process goes to the periphery, the other goes to the spinal cord where it makes synaptic contact with nerve cells in the spinal cord ( = 2nd order neurons).
The 2nd order neuron sends processes to other nerve cells in the spinal cord and to the brain.
2nd Order Nerve Cells Send Nerve Fibers In The Spinal Cord White Matter
Transmission Of Nociceptive Signals From The Periphery To The Brain
Silverthorn
A Delta (?) & C Nerve Fibers
Nerve fibers are classified according to the:
� (1) diameter of the nerve fiber and
� (2) whether myelinated or not.
A? and C nerve fiber endings respond to strong stimuli.
A? are myelinated and C are not.
Action potentials are transmitted 10 times faster in the A?
(20 m/sec) fibers than in C fibers (2 m/sec).
A? & C fibers
A? fibers respond mainly to mechanical and mechno-thermal stimuli.
C fibers are polymodal, i.e. the nerve ending responds to several modalities � thermal, mechanical and chemical
This polymodal ability is due to the presence of different receptor molecules in a single nerve ending.
Fast & Slow Pain
Most people when they are hit by an object or scrape their skin, feel a sharp first pain (epicritic) followed by a second dull, aching, longer lasting pain (protopathic).
The first fast pain is transmitted by the myelinated A? fibers and the second pain by the unmyelinated C fibers.
Central Pain Pathways
Nociceptive signals are sent to the spinal cord and then to different parts of the brain where sensation of pain is processed.
There are a pathways/regions for assessing the:
Location, intensity, and quality of the noxious stimuli
Unpleasantness and autonomic activation (fight-or-flight response, depression, anxiety).
Dr. Sletten Discussing Central Sensitization Syndrome (CSS)
Pain perception varies across different people based on their mood, psychological condition and previous experience, even when pain is brought on by similar physical stimulation and ends in a similar level of damage. In 1965, Ronald Melzack and Patrick Wall summarized a scientific theory about the psychological influence on pain perception; known as the gate control theory.
If it wasn’t for this theory, pain perception would still be connected to the intensity of the pain stimulation and the degree of damage caused to the affected tissue. But Melzack and Wall made it clear that pain perception is far more complicated than we believe.
Based on the gate control theory, pain signals aren’t free to travel to the brain as soon as they’re generated in the region of the damaged or injured tissues. These first need to encounter specific neural gates found at the level of the spinal cord level, where these gates ascertain whether the pain signals should reach the brain or not. To put it differently, pain is perceived when the gate gives way to the pain signals and it is not as intense or it is not sensed at all when the gate closes for the signs to pass through.
This theory provides the explanation for why people find relief by massaging or rubbing a damage, injured or painful site. Although the gate control theory cannot demonstrate the whole picture of the fundamental system which underlies pain, it’s visualized the mechanism of pain perception and it has created a pathway to various pain management treatment approaches.
Nerve Fibers in Transmission of Sensory Signals
Every organ, or portion of the human body, has its own nerve supply which are in charge of carrying electric impulses generated in reaction to several senses, such as touch, temperature, pressure and pain. These nerves, which make up the peripheral nervous system, transmit these sensory signals, to the central nervous system, or the brain and the spinal cord. These impulses are then translated and perceived as senses. The peripheral nerves send signals to the dorsal horn of the spinal cord and from there, the sensory signals are transmitted into the brain through the spinothalamic tract. Pain is a sensation which alarms a person that a tissue or certain portion of the human body has been damaged or injured.
Due to their axonal diameter and their conduction speed, nerve fibers can be categorized into three different types, nerve fibers A, B and C. The C fibers are considered to be the smallest among the three different types. Moreover, there are four subtypes within the A fibers: A-alpha, A-beta, A-gamma and A-delta. From the A fiber subtypes, the A-alpha fibers are the largest and the A-delta fibers are the smallest.
The A fibers which are larger compared to the A-delta fibers, carry sensations, such as touch, pressure, etc., into the spinal cord. The A-delta fibers as well as the C fibers carry pain signals into the spinal cord. A-delta fibers are faster and carry sharp pain signals while the C fibers are slower and carry diffuse pain signals.
When thinking about that the conduction velocity of nerve fibers, the A-alpha fibers, which are the biggest A nerve fibers, have greater conduction speed compared to A-delta fibers and C fibers, which are considered to be the smallest nerve pathways. When a tissue is damaged or injured, the A-delta fibers are activated first, followed by the activation of the C fibers. These nerve fibers have a tendency to carry the pain signals to the spinal cord and then to the brain. However, the pain signals are transmitted through a much more complex process than what is simply explained above.
The gate control theory implies that the sensory signals or impulses which are transmitted by the nerve fibers encounter neural gates at the level of the spinal cord and these will need to get cleared through those gates to reach the brain. Various factors determine how the pain signals ought to be treated in the neurological gates, including:
The intensity of the pain signals
The degree of another sensory signal, such as touch, temperature and pressure, if produced at the site of damage or injury
The message from the brain itself to deliver the pain signals or not
As previously mentioned, the nerve fibers, both large and small, carrying the sensory signals, end in the dorsal horn of the spinal cord from where the impulses are transmitted into the brain. According to the original postulate of Melzack and Wall, the nerve fibers project to the substantia gelatinosa, or SG, of the dorsal horn and the initial central transmission (T) cells of the spinal cord. The SG consists of inhibitory interneurons that behave as the gate and ascertain which sensory signals should get to the T cells then go further throughout the spinothalamic tract to finally reach the brain.
When the pain signals carried by the small nerve fibers, or the A-delta fibers and the C fibers, are somewhat less intense compared to another non-pain sensory signal like touch, temperature and pressure, the inhibitory neurons stop the transmission of the pain signals through the T cells. The non-pain signals override the pain signals and therefore the pain is not perceived by the brain. When the pain signals are somewhat more intense compared to the non-pain signals, the inhibitory neurons are inactivated and the gate is opened. The T cells transmit the pain signals into the spinothalamic tract which carries those impulses to the brain. As a result, the neurological gate is influenced by the relative amount of activity from the large and the small nerve fibers.
How Emotions and Thoughts Affect Pain
The gate control theory also suggests that the pain signal transmission could be affected by thoughts and emotions. It’s well known that people do not feel that a chronic pain or, more appropriately, the pain does not disturb them if they concentrate on other activities which interest them. Whereas, people who are depressed or anxious may often feel intense pain and can also find it challenging to cope with. This is due to the fact that the brain sends messages through descending nerve fibers which stop, reduce or enhance the transmission of pain signals through the gate, depending on the emotions and thoughts someone may be going through.
Gate Control Theory in Pain Management
The gate control theory has caused a radical revolution within the field of pain management. The theory suggested that pain management can be accomplished by influencing the larger nerve fibers that carry non-pain stimulation. The concept has also paved way for more research on cognitive and behavioral strategies to achieve pain relief.
Among the most tremendous advances in pain management research is the arrival of Transcutaneous Electrical Nerve Stimulation (TENS). The gate control theory forms the cornerstone of TENS. In this procedure, the selective stimulation of the large diameter nerve fibers taking non-pain sensory stimulation from a particular region nullifies or reduces the impact of pain signals from the region. TENS is a non-invasive and affordable pain control strategy that has been widely used for the treatment of chronic and intractable pain by various healthcare professionals, which may otherwise have been non-responsive to analgesics and surgical interventions. TENS is tremendously advantageous over pain drugs from the aspect that it does not have the problem of medication interactions and toxicity.
For instance, many doctors of chiropractic, or chiropractors, utilize TENS and other electrotherapeutic procedures in their practice. These are generally utilized along with spinal adjustments and manual manipulations to increase circulation as well as to aid in the support of chiropractic care. Several other invasive and noninvasive electrical stimulation techniques are discovered to be helpful in several chronic pain conditions such as arthritic pain, diabetic neuropathy, fibromyalgia, etc.. The theory has also been extensively studied in treating chronic back pain and cancer pain. However, favorable results are not attained in some conditions and the long term efficacy of these techniques based on the theory still remains under consideration.
Dr. Alex Jimenez’s Insight
Chiropractic care is widely utilized to benefit patients with chronic pain. Symptoms of persistent pain and discomfort have become a big health issue in the United States where many years of research have found that drugs and/or medications are not necessarily a solution to the problem. The gate control theory, which was first proposed over half a century ago, has offered healthcare professionals new insights on the perception of pain, providing a variety of pain management treatment methods, such as the use of transcutaneous electrical nerve stimulation, or TENS, as well as other electrotherapeutic procedures. Chiropractors can help with pain management through spinal adjustments and manual manipulations, and through the use of TENS.
Nevertheless, the gate control theory has radically revolutionized the area of pain research and it has achieved to get numerous studies which aim at presenting a pain-free lifestyle into the patients who suffer from chronic pain. The scope of our information is limited to chiropractic as well as to spinal injuries and conditions. To discuss the subject matter, please feel free to ask Dr. Jimenez or contact us at 915-850-0900 .
Curated by Dr. Alex Jimenez
Additional Topics: Sciatica
Sciatica is medically referred to as a collection of symptoms, rather than a single injury and/or condition. Symptoms of sciatic nerve pain, or sciatica, can vary in frequency and intensity, however, it is most commonly described as a sudden, sharp (knife-like) or electrical pain that radiates from the low back down the buttocks, hips, thighs and legs into the foot. Other symptoms of sciatica may include, tingling or burning sensations, numbness and weakness along the length of the sciatic nerve. Sciatica most frequently affects individuals between the ages of 30 and 50 years. It may often develop as a result of the degeneration of the spine due to age, however, the compression and irritation of the sciatic nerve caused by a bulging or herniated disc, among other spinal health issues, may also cause sciatic nerve pain.
Infantile Colic: If you have ever cared for an infant with colic, you know how frustrating and helpless it can make you feel. It is so hard to see a little one in such obvious discomfort and you can�t help them no matter what you do. When you have a baby who experiences frequent colic it can be heartbreaking. An infant is so small and they can�t tell you where it hurts or what is wrong; all they can do is cry.
Chiropractic has been proven to help with infantile colic. It can soothe fussy babies and ease the nerves of frazzled parents. Some moms and dads may be a little ambivalent about the idea of having a chiropractor �work� on their baby, but the benefits are incredible � and baby�s comfort is definitely worth it.
What Is Colic?
Colic is a condition that has frustrated parents since the beginning of time. The most prevalent symptom is the severe distress that occurs over predictable periods of time. It is labeled colic when there is no obvious underlying condition that could cause the distress, and occurs in babies that are newborn to 3 months (sometimes up to 6 months), healthy and well fed.
The bouts of crying and distress can last hours, days, or even weeks. Often it seems that there is no way to comfort the baby or provide relief. Symptoms of colic include:
Crying that does not seem to have a reason
Crying that is intense and indicates obvious distress
Crying that occurs at predictable times
Changes in posture that include tense abdominal muscles, clenched fists, and curled legs.
What To Expect When You Take Your Infant To A Chiropractor
Some parents may balk at taking their infant to a chiropractor, their minds filled with images of the stereotypical snap, crackle, and pop that is so often associated with the practice. However, infant chiropractic is different and much milder. Chiropractic adjustments for infants are very gentle.
The chiropractor will use his fingers to gently apply pressure to areas on the back and neck. Most babies completely relax as the doctor corrects the misalignments � some even fall peacefully asleep. When you are choosing a chiropractor for your baby, ask if he or she is experienced in working with babies.
How Chiropractic To Treat Colic Works
Childbirth is not a gentle experience. As the baby�s tiny body is compressed and stretched as it is emerging into the world, it can cause the vertebrae of the neck and back to become misaligned. If the delivery included vacuum extraction, forceps, or prolonged pushing, or other things that doctors or midwives must do to assist in delivery, the chances that the baby will experience misalignment are very good.
When these misalignments, called vertebral subluxations, are significant enough, it can impede on how well other major systems in the body are able to function. Digestion is one area that can be greatly impacted and when digestion of formula or breastmilk is compromised it can be the cause of major distress and discomfort for the baby. This can lead to episodes of colic.
Studies That Support How Chiropractic Helps Infantile Colic
There have been several studies that explores the efficacy of chiropractic for colic. The majority of this research has shown that it is a very effective treatment.
A 1999 study published in the Journal of Manipulative and Physiological Therapeutics reported that spinal manipulation for colic is a very effective treatment for the condition. Babies treated using chiropractic experienced a decrease in crying by 67 percent. Babies who received medication experienced a decrease in crying by 38 percent. Another study showed similar results. Chiropractic improved crying behavior in babies that had colic.
Chiropractic is an effective, gentle, and drug free way to treat colic. Babies can thrive and be free of distress and discomfort while mom and dad can get some much needed sleep � and peace of mind.
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Brain Areas Involved In Processing Of Nociceptive Signals
The Anterior Cingulate & Insula Cortex Are Activated In Human Subjects
Inflammatory Soup – Hyperalgesia
Gate Control Theory of Pain
Abnormalities Of Pain System
Peripheral Sensitization
Somatosensory Cortex Organization
Cortical Reorganization
Nerve Cell-To-Nerve Cell Communication
Nerve cells communicate with other cells by releasing a chemical from the nerve endings � Neurotransmitters
TRP Channels
