Phantom pain refers to the phenomenal experience of pain in a body part that has been amputated or deafferented (Flor, Nikolajsen & Jensen, 2006). The characteristics of phantom pain have been described to occur in quick and sudden attacks of pain shooting up and down the amputated limb as well as cases of constant, excruciating pain whilst intensely perceiving the amputated limb to be cramped or postured abnormally (Katz, 1992). Approximately eighty percent of amputees report suffering from or at least experiencing some level of phantom pain post amputation; therefore it is a prominent issue (Flor, Nikolajsen & Jensen, 2006). Phantom pain is neuropathic pain that has no individual trigger but instead a plethora of psychobiological aspects of neuroplasticity that contribute to the cause of phantom pain (Grusser, Diers & Flor, 2003). The following will: outline the role of the peripheral and central factors associated with phantom pain and discuss the cortical reorganisation of the somatosensory cortex in relation to phantom pain.
Peripheral and central mechanisms involving nerve lesions and their input are substantial when perceiving phantom pain. Due to the impairment of peripheral nerves in the process of amputation, regenerative sprouting of damaged axons occurs and the activity rate of inflamed C-fibres and demyelinated A-fibres spontaneously increases (Flor, 2002). As a consequence of this nerve injury, a neuroma, which is a mass of pruned and tangled axons, may form in the residual limb producing abnormal (ectopic) activity (Katz, 1992). Flor, Nikolajsen and Jenson (2006) proposed that ectopic discharge from a neuroma in the stump illustrates abnormal afferent input to the spinal cord, which is a possible mechanism for unpro...
... middle of paper ...
..., suggesting that cortical reorganisation mediates this relationship Flor (2002).
Overall, there is an immense amount of research dedicated to understanding the psychobiological causes of phantom pain. A prevalent commonality between the literatures reviewed, suggested that symptoms of phantom pain are a neuro-psychobiological experience rather than a psychological disorder. This was evident by peripheral and central factors that associate the cause of phantom pain with the disruption of sensory nerve impulses due to the damage of sensory nerve fibers after amputation. As well as studies that demonstrated a positive correlation between progressive neuroplastic changes in the cortical reorganisation of the topographical structure in somatosensory cortex and worsening phantom limb pain, inferring that cortical reorganisation mediates the extent of pain experienced.
Three lines of evidence suggest that PVS patients are "noncognitive, nonsentient, and incapable of conscious experience [12]." First, motor and eye movement, and facial expressions in response to stimuli occur in stereotyped patterns rather than learned reactions. Second, positron emission tomography reveals cerebral glucose metabolism at a level far below those who are aware or in locked in states. PVS levels are comparable to those in deep general anesthesia and as such are totally unaware and insensate. Third, neuropathological examinations of PVS patients show "lesions so severe and diffuse [12]" that it would be almost impossible, giving our current understanding of neural an...
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...
Peripheral nerves are categorized as both sensory and motor which means they help provide sensations and move ligaments. These nerves attach to the spinal cord and run throughout the human body. Damaging these nerves may result in peripheral neuropathy. This condition is the degenerative state of the peripheral nerves. During this state, nerves may lose the ability to function therefore, causing multiple problems with one’s body. There are multiple causes to this condition and many can be avoided.
According to the U.S census, about 80% of people with phantom limb experience extreme excruciating pain coming from the stump. In fact, Ramachandran and Hirstein authors of “The Perception of Phantom Limbs” (1998) report that the pain haunts victims and remains painful even 25 years after loss of limb. Hence, suffering is chronic especially after an immediate amputation of a limb, where patients describe the pain as itching, burning, stabbing, or tingling. In most cases, pain interferes with work and social life and becomes a heavier burden than the paralysis itself. There’s nothing really phantom or imagined about this suffering; however, contrary to what the amputees feel, the pain is generated by the brain not originated in a limb that doesn’t exist. To be more specific, the intensity of the pain could be found in the neurons of the brain. With this in mind, one must be sure that phantom limb syndrome is certainly not a modern discovered occurrence; however, the exact cause of this sensation has puzzled scientists for dec...
Chronic paresthesia is commonly a manifestation of an underlying neurological sickness or traumatic nerve harm. Paresthesia may be brought on by disarranges that influence an individual's focal sensory system, for example, transient ischemic ambushes or strokes, encephalitis, various sclerosis, or t...
Circumcision, the removal of the foreskin over the penis, was long thought to be a painless experience for an infant and was treated accordingly with little or no anesthesia. Most of the times during the surgical procedure, the babies cry very forcefully. This was for a long time thought to be normal and healthy. Other times, they lie still without making a sound from either shock or the act of passing out from the pain (1). This unresponsiveness was always thought to be from undeveloped pain receptors, or Nociceptors in the Somatosensory system (2) . These pain receptors send information to the spinal cord, then to the brain stem, thalamus, and somatosensory cortex. Modulation can occur through these pathways by way of suppression using large mechanosensitive fibers that enter the spinal cord or by endorphine release. This modulation involves changing the information about the pain to lessen the perception of its magnitude.
For example, phantom pain is a well-known phenomenon in medicine. When people lose a limb, they will often feel painful spasms in parts that no longer exist. Although neuroscience is still developing, scientists assume sensory conflict is responsible for this phenomenon (Blakeslee, 1995b). The brain remembers the nerves going to the missing limb and their previous function, so it can issue orders through those nerves. However, the nerves will not get feedback from the muscles in the non-existent limb, so the brain stops the movement forcibly (Blakeslee, 1995b). Over time, the brain makes new nervous pathways and adapts to the new geography of the body (Blakeslee, 1995b), so the person's perception changes and phantom pain no longer persists.
Somatic pain is that in which nociceptors in the cutaneous or deep tissues are activated by noxious stimuli. This is usually characterized by dull, aching pain which is well localized. This type of pain may be commonly experienced by individuals with metastatic bone pain or those who h...
Phantom Limb Syndrome is when a patient has lost a limb, such as a body part (organs), an arm or leg, but can still feel the presents of the limb and is “able” to continue functions with the arm because of the presents of the phantom. This syndrome can be caused by losing a limb in a tragic accident or by being born without a limb or limbs. When people are born without the limb or limbs and have this syndrome it can be described as wishful thinking or by having a soul. Wishful thinking is where the person wishes that they have the syndrome but they actually do not even if they are showing the signs of having the syndrome. This sort of thinking can be shown in the case of John McGrath who was an arm amputee that had co...
The common fibular nerve is a branch off of the sciatic nerve, which originates from L4 and L5. The deep fibular nerve has motor and sensory functions. The motor functions include the innervation of the anterior leg. It also supplies sensory function for the region between the first and second toes (“The Deep…”). My teammate’s lack of feeling to that region indicates loss of sensory function for the deep fibular nerve.
Increasing amount of research in recent years has added to developing knowledge of phantom limb pain (PLP). In this research proposal I aim to test the mirror therapy as an effective treatment in PLP. Phantom limb pain occurs in at least 90% of limb amputees. PLP may be stimulated by disconnection between visual feedback and proprioceptive representations of the amputated limb. Therefore, I will research both the neurobiology behind this phenomenon and whether illusions and/or imagery of movement of the amputated limb (mirror therapy) is effective in alleviating PLP of lower limbs. Mirror therapy has been used with noted success in patients who have had upper body amputation, but has not been determined in lower limb amputations. I would like to identify if form of treatment is equally effective in lower limb amputations. Yet, to consider mirror therapy as an effective means of treatment, one must understand PLP in its entirety. The main concern being if a limb is no longer attached to the body, how can neurons in the limb transport signals to the nervous system in order for the body to detect sensations? The biological significance of this project is to determine what occurs on the sensory level to cause PLP. Once that is discovered we can address whether or not mirror therapy is a plausible form of treatment.
The previous insert from William Lee Adams’ article, Amputee Wannabes, describes a 33-year-old man’s wish for amputation of his foot. There was nothing physically or medically wrong with this limb; John only stated that he did not feel comfortable with his own body and felt as though his foot was not a part of him. John’s leg was amputated above the knee, and he went on to describe that the operation resolved his anxiety and allowed him to be at ease in his own body (Adams, 2007).
M.M. Merzenich, R. N. (1984). Somatosensory cortical map changes following digit amputations in adult monkeys. Journal of Comparative Neurology, 224(4): 591-605.
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...
In life, many things are taken for granted on a customary basis. For example, we wake up in the morning and routinely expect to see and hear from certain people. Most people live daily life with the unsighted notion that every important individual in their lives at the moment, will exist there tomorrow. However, in actuality, such is not the case. I too fell victim to the routine familiarity of expectation, until the day reality taught me otherwise.