Transmission of Pain Signals by the Brain at the Spinal Level Pain has been defined by Coates & Hindle as an unpleasant emotional and sensory experience which signals a potential or actual damage to tissues (2011, p. 213). Pain is a common human experience and can emanate from injury and illness. There are two main types of pain; acute pain is short-lived, lasting for minutes or several days and its onset often takes place rapidly. It results from the activation of pain nerve endings or nociceptors either by internal or external pain stimuli. On the other hand chronic pain is continuous and sometimes recurrent and can last for weeks, months or even years. Chronic pain is usually not located at or related to the tissue undergoing trauma (Draper & Knight, 2007, p. 104). Various theories have been proposed to explain the mechanism underlying the transmission and perception of pain. These include the specificity theory which maintains that specific fibers and pain receptors are activated by injury after which the pain signals are projected via the spinal pathway to an area in the brain that interprets the pain. In this regard, the specificity theory virtually equates the peripheral injury with the psychological experience caused by the pain (Anderson, 2004, p. 355). However, this theory has been found to harbor several limitations as research about pain has intensified with time. In light of this, the gate theory that was proposed by Melzack and Wall has had a major contribution to the understanding of pain transmission and perception (Pain Game Part 2, 2011). Research has demonstrated that pain is affected by psychological and physiological factors which helps to explain the mechanism underlying inhibition and/or facilitaion of pai... ... middle of paper ... ...t has been noted that the gate control theory proposed by Melzack and Wall in 1965 formed the foundation of understanding the process of pain signal transmission. The dorsal horn of the spinal cord is the region of the CNS that controls the passage of pain signals by means of opening and/or closing the gate. Pain can only be perceived if reaches the brain. Events that cause excitation such pain signals and the release of excitatory or facilitatory chemicals cause the gate to open whereas inhibitory events such as competing nerve impulses caused by rubbing trigger closure of the gate. The gate can also be closed due to descending inhibition enhanced by relaxation or the use of pain-relieving medication such as morphine. The brain stem is responsible for controlling the transmission of pain signals via the ascending and descending pain pathways.
Based on the findings presented, Dr. Green made the correct diagnosis in predicting that this gentleman had a spinal cord injury.
It has been shown that intrathecal administriton of GABA receptor antagonists cause hyperalgesia and allodynia. Constitutive, the increase in the endogenous GABA activity in the spinal cord alleviate pain resulting from noxious and innoxious mechanical and thermal stimuli. Different GABA receptors have different roles in alleviating thermal and mechanical pain in different animal pain models. There is no study to date that has examined the involvement of GABA A and GABA B in sensory dimension of neuropathic pain resulting from compression of spinal cord. The current study tests the hypothesis that GABA A or GABA B receptors contributes to the allodynia and hyperalgesia observed after spinal cord injury. The results showed that the effect of GABA A and GABA B receptors on mechanical hyperalgesia is similar but these receptors have different effects on thermal hyperalgesia. While using baclofen as GABA B receptor agonist does not affect the thermal pain, thermal hyperalgesia resulting from spinal cord injury was greatly alleviated by different doses of GABA A agonist, muscimol. Both Baclofen and muscimol are able to reduce the mechanical and cold allodynia has been seen after spinal cord injury but the effect of baclofen is dose dependent with no effect in higher doses used in this study. While almost all doses of muscimol were used in this study reduce the amount of cold and mechanical allodynia. The other result obtained in this study is the short term effect of GABA agonist. The anitinociceptive effect of Baclofen and muscimol appear to be maxium at 15 min after injection and gradually diminished by time and their analgesic effect disappeared 3 hours after injection.
The most common and well described pain transmission is “gate control theory of pain”. This theory was first proposed by Melzack and Wall in 1965 whereby they used the analogy of gate to explain the inhibition of pain which exists within the dorsal horn of the spinal cord. For instance, when tissue damage occurs, substances such as prostaglandin, serotonin, histamine and bradykinin are released from the injured cell. Individual usually consume or apply pain medications such as NSAIDs whereby these medications will cause electrical nerve impulse at the end of the sensory nerve fiber via nociceptor. Nociceptor is a pain receptor that is commonly found in the skin, cornea of eye and organ of motion such as muscles and ligaments. These nerve impulses
The body is controlled down to its core by the central nervous system. The central nervous system consists of the brain and the spinal cord. Both of these are made up by white and gray matter. The brain which has gray matter on the outside and white matter on the inside is responsible for processing the information that it receives from the nerves and spinal cord, sending out responses, and coordinating motor functions. The spinal cord is opposite of the brain and has gray matter on the inside and white on the out. The spinal cord conducts the information or messages it receives from the brain to the body and sends its “research” back to the brain for processing.
In 1931, the French medical missionary Dr. Albert Schweitzer wrote, "Pain is a more terrible lord of mankind than even death itself." Today, pain has become the universal disorder, a serious and costly public health issue, and a challenge for family, friends, and health care providers who must give support to the individual suffering from the physical as well as the emotional consequences of pain (1).
Craig, A. D. (n.d.). Mapping pain in the brain. Mapping pain in the brain. Retrieved November 18, 2013, from http://www.wellcome.ac.uk/en/pain/microsite/science2.html
The spinal cord is a major channel in the body where motor and sensory information travels from the brain to the body. It has white matter that surrounds a central gray matter. The gray matter is where most of the neuronal cells are located. Injury to the spinal cord will affect the conduction of information across any part of the spinal cord where the damage is located (Maynard et al., 1997). This will often result in permanent disability of a certain muscle or region of the body (Meletis et al., 2008) and a loss of tissue where the damage is located (Peng et al., 2009). As of now, there is no treatment for spinal cord injury expect for steroids. All steroids can do is provide protect of the spinal cord from secondary injury for specific patients (Peng et al., 2009).
The gate control theory of pain states that non-painful input closes the "gates" to painful input, which prevents pain sensation from traveling to the central nervous system. Stimulation by non-noxious input is able to suppress pain (Melzack). The gate control theory of pain asserts that non-painful input closes the "gates" to painful input, which prevents pain sensation from traveling to the central nervous system. The human brain is the key component in the sensation of pain.
Pain is a complex and subjective phenomenon that involves biological, psychological, social factors, and cultural. It is interpreted and perceived in the brain. Each individual responds differently to pain because every person has different pain thresholds and tolerances. According to Porth (2009), pai...
A crucial concept in the definition of pain is that it is indeed a perception, therefore involving the brain's rumination and elaboration on corresponding input. This may be paralleled to another sensory perception, vision. Although the optic nerve head should cause a "hole" in an individual's...
Conclusions. An adequate and clear understanding of the concept of pain and implementing interventions of pain treatment and management is essential in the clinical settings. Understanding the concept of pain is necessary for its relationships with other concepts that are related and similar to the pain experience for theory building. The in the end, understanding the concept of pain will ultimately benefit the patient and lead to better and approp...
Nociceptors respond to potentially damaging stimuli by sending signals to the spinal cord and brain. This process, called nociception, usually causes the perception of pain. They are found in internal organs as well as on the surface of the body. Nociceptors detect different kinds of damaging stimuli or actual damage. Those that only respond when tissues are damaged are known as "sleeping" or "silent" nociceptors.
college of obstetricans in 2010, they state that the cortex is needed in order to feel pain. Another
The Gate- Control theory conceives that the spinal cord contains a neurological “gate” that either blocks pain signals or allows them to pass on to the brain. The spinal cord contains small nerve fibers that conduct most pain signals and larger fibers that contain most other sensory signals. When the tissue is injured, the small fibers activate and open the neural gate causing...
Pain is defined by the International Association for the Study of Pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage" (1). When pain is described in these terms we can see that pain is a perception, sort of like seeing and hearing. When pain is processed there are a number of brain structures activated, commonly referred to as the "central pain matrix" (2). It may seem irrelevant to delve into pain signal activation in the brain since it is seemi...