Describing Phantom Limb Experience Essay

Gawande wrote about a woman named M. who scratched through her skull to her brain in her sleep. The scratching only gave her momentary relief before the urge to scratch just grew bigger making the annoyance worse. Since pain was thought to be so closely linked to itching through nerves, M’s doctors thought that the only way to get rid of the itch was to cut off the function to the nerves where the itch was present. After losing the feeling in her face and after taking anesthetics and antibiotics the urge to scratch still came back, becoming more of a chronic itch. Fueling Gawande's theories about the itch, he theorized that maybe there is nothing wrong with the nerves at all. He thought that there was something going wrong in the brain when it tells your body that you need to scratch, when clearly you do not. After becoming more in depth with M’s case, Gawande then introduced a man named H.. H. suffered from strange symptoms of phantom limbs. Phantom limb sensations were described as, “... far too varied and rich to be explained by the random firings of a bruised nerve” (Gawande, 2008). Gawande's theory expanded by theorizing that the brain can't visually see that the person/self is healed when the nerve transmissions are shut off due to

Gertler clarifies that pain refers to the sensation and not the common cause, which is C-fibers firing in a specific area with tissue damage. (109) She asserts that pain is not essentially connected to tissue damage of a particular location, indicating to me inadequate understanding of the concept. If one pinches one's arm, though the sensation of pain may not be necessarily located in the arm, I contend that the pain felt is relevantly connected to the location pinched. Gertler provides the alleviating effect of painkillers as an example of a non-essential feature of pain. (117) Location is unlike this property, however, and is essential in conceptualizing pain. For instance, even an amputee, who had a leg removed and experiences a phantom leg-pain, is unable to describe the sensation they feel without making reference to a specific body part. Whether or not the pain is actually “located” anywhere is irrelevant, it matters only that the pain is conceptualized as having a location. Our understanding of pain relies fundamentally on where the pain is thought to be “located.” The fact that it is impossible to conceive of pain without reference to the “location” of the sensation proves that location is an essential feature of

“The Human Brain”, by myPerspectives, is an informative article that claims that the brain is a complex organ that is truly impressive. The brain is a key part of the central nervous system, that controls the entire body’s activities, to simple things such as breathing. These actions are fired through neurons, that quickly travel through the spinal cord. Surprisingly, the brain transmits these messages at an unimaginable rate, at 150 miles per hour, through 85 billion cells, called neurons. These neurons can form up to 10,000 synapses, or connections to each other. By itself, the brain can create billions of synapses, which change the structure of the brain every time new information is learned. However, there is still much that scientists

Many researchers have sought out an explanation for the mysteries hidden within our brain and how it operates. Recent studies have shown that the brain functions more as a muscle allowing it to continue to grow or contract. If these studies prove to be true, this could forever change how people interact or associate with their brains.

The progress of neuroscience has been significant in the past 500 years. and with the advance of technology, there is yet a multitude of chapters left to write in the history books of neuroscience. The book The Tale of the Dueling Neurosurgeons: written by Sam Kean was an engrossing and captivating read. It gives the reader a better appreciation for the growing pains of neuroscience and provides an educational, albeit entertaining overview of the anatomy and physiology of the brain and nervous system. From the early life and discoveries of Santiago Ramón y Cajal and his fascination with Golgi’s method la razione nera, which allowed Cajal to deduct after observing

When a body part is lost the corresponding part of the brain is not able to handle the loss and rewires its circuitry to make up for the signals it was no longer receiving from the missing digit. The rewiring might occur in one of two ways. Perhaps nerve impulses in the sensory cortex begin to course down previously untraveled pathways. The second theory is that neighboring neurons in the cortex may actually invade the territory left fallow because sensations are no longer received from the missing limb.

The phantom limb pain the woman is experiencing is described as a painful condition of the amputated limb after the stump has completely healed. It is a chronic pain that occurs in more than 80% of amputees especially those who suffered pain in the limb before the amputation. Theories suggest that phantom limb pain results from redevelopment or hyperactivity of cut peripheral nerves, scar tissue or neuroma formation in the cut peripheral nerves, spinal cord deafferentation, and alterations in the thalamus and cortex. More so, the CNS integration, which involves reorganization and plastic modifications of the somatosensory cortex, effects the receptors in perceiving the pain of the amputated limb despite of the limb itself being absent. In addition,

It is here that one may believe that Dennett makes a mistake by categorizing his brain and his body as two distinct entities. After all, he claims that his brain, after surgery, will be "kept in a safe place where it could execute its normal control functions by elaborate radio links" (ibid, 379). In other words, these radio links are intended to take the place of normal neurological pathways such that "no information would be lost, all the connectivity would be preserved" (ibid, 379). Thus, after surgery, while there does exist a great temporal gap between his brain and his body, the relevant connection between the two does not appear to be much different than the connection between the brain and the body of someone with a "normal" temporal gap. And since the connection is still, in essence, the same regardless of however peculiar Dennett's case may be, it could be concluded that Dennett is no more entitled to name and categorize his body and his brain as distinct entities than anyone else.

The concept of neuroplasticity has long been questioned. The term of “neuroplasticity” did not even come about until the mid-late 20th century. When the term “plastic” was used to describe the brain by a select few neuroscientists, they were laughed at and the term was never thought of as a description for the human brain. The human brain was seen as a closed circuit and one that once you had it, you definitely had it. Scientists thought the brain would not develop anymore past a certain point in your life. Norman Doidge brings the concept of neuroplasticity into reality in his book “The Brain that Changes Itself,” a book about the triumphs in the frontier of brain science.

Further studies in 1998 investigating the re-mapping component in the brain were conducted by researchers at the University of Toronto and The Toronto Hospital. The study recruited amputees who experienced phantom pain for surgery to map the sensory areas in the brain. During the mapping process, the conscious patients reported sensations they felt when certain areas of the thalamus were stimulated. Patients reported phantom sensations when areas of the thalamus were stimulated that formally were innervated by neurons from the missing arm, and also when areas on the stump were stimulated that activated these reorganized regions in the brain. Neurons were shown to continue to carry out their original roles, but with different sources of activation (7).

The earliest hypothesis regarding the cause of phantom limbs and pain was that of neuromas. These were thought to be nodules comprised of remaining nerves located at the end of the stump. These neuromas presumably continued to generate impulses that traveled up the spinal cord to portions of the thalamus and somatosensory domains of the cortex. As a result, treatment involved cutting the nerves just above the neuroma in an attempt to interrupt signaling at each somatosensory level (5). This and other related theories were deemed unsatisfactory because of the fact the phantom pain always returned, indicating that there was a more complex reason.

Phantom limb syndrome is an extraordinary condition that is caused by amputating a limb or being born without a limb (Flor, 2002); This condition affects approximately 80% to 90% of patients who have had a limb amputated (Flor, 2002). The first documented case of phantom limb syndrome was in the mid 16th century (Nikolajsen & Jensen, 2001). The description was given by a French military surgeon by the name of Ambroise Paré (1510–1590) when he noticed that some of his injured patients would express that they were experiencing extreme pain in their missing limb (Nikolajsen & Jensen, 2001). He studied and wrote down the characterizations of this post-amputation state and attempted to create different models to explain how the phantom pain was

Sacks discussed the ideas behind the phantom limb and how they affected many peoples live. The most interesting story was about a sailor that accidentally cut off his index finger. For forty years he thought he would poke himself in the eye whenever he moved his hand to his face. One day he lost the feeling in his entire hand including his phantom finger and his problem was cured (Sacks 66-67). Up to 70 percent of amputees confirmed that they still feel or still thought a missing limb was there. They often feel that they can reach out and grab something. Some won't sleep in a certain way because they feel the missing limb between them and the mattress. The sensations felt stem from the activity of the sensory axons

systems sense feeling because it has electrical sensors in the prosthetic limb to detect the

The neurons in the brain tissue communicate with each other via electrical signals, generating measurable action potential activity. Electrophysiological techniques have been developed to measure this electrical activity. Electrophysiological techniques are some of the classic methods of brain research, partly because they are very sensitive and accurate. They provide quite a number of insights into the subject’s mind as well as allow for study of how the brain works. They can be used during brain surgery as well as when the patient is awake and conscious, as the brain itself does not sense pain during the measurements. Although electrophysiology has been around for close to half a century, it has attained appreciable advances only in the last two decades. These advances have revolutionized the study of brain structure and functions, allowing neurophysiologists to monitor the brain’s activities directly during experiments (Sutler et al., 1999). Even with its significant impact in neurology, however, its presence has been so commonplace that many people no longer realize its ubiquity. This essay explores three electrophysiological techniques namely patch clamp, sharp electrodes, and brain slice recording. It describes how each of these techniques works as well as how advances in the techniques have