Anosognosia_and_Phantom_Limb

Running Head: Anosognosia and Phantom limb George N.M. D. Ann B.S. 03.01.010 Introduction Bizarre syndromes such as anosognosia & phantom limb result from changes in regions of the nervous system that are somehow involved in producing our normal awareness of our own body parts & their positions (body image). In cases of phantom limb, amputees continue to experience sensations from a non existent limb. In anosognosia, brain-damaged patients perceive that a paralyzed or otherwise non-functional part of their body is functioning normally. Both of these abnormal neurological conditions are the direct result of damages to the controlling centers in the human brain. These two syndromes demonstrate contrasting characteristics in terms of their external symptoms and mode of transmission of the sensory messages from their respective receptor regions. The waves of messages are transmitted towards the brain centers for initiation of necessary neurophysiologic chain of reactions for the completion of neuromuscular activities. Anosognosia & phantom limb syndromes causes impairment of the body’s normal awareness system. A comprehensive analysis of these two disorders will reveal the normal pattern of physiological working of the human body. This is due to the fact that these two disorders affect the sensory components that control the effective coordination of the central nervous system. The study will provide necessary guidelines to future researchers in the field of neurology and will help them understand these two abnormal physiological conditions. This will in turn ensure that these conditions are effectively addressed. The Anosognosia and phantom limb syndromes relate with the sensory systems, neuromuscular arrangements and central nervous system including the brain and the spinal cord. The pattern as adopted in the study will also serve as a model for making comprehensive analysis of the other human systems in their normal patterns. Phantom limb and Anosognosia "Phantom limb" and "Anosognosia" are the conditions in which sensory centers of the human body continue to function as sensory receptors in spite of the distorted anatomical and physiological changes in the related body parts. The following is a detailed discussion of how these two conditions affect the normal awareness of ones body as well as ones self. a. Phantom Limb: The “Phantom limb” is a disorder in the sensation system which is generated by a missing limb or organ such as the appendix. This causes a patient to feel that absent body organ is still functional (Halligan &Berger, 1999.p.587) (1). Only less such conditions are found to be painful. According to statistics, approximately 5-10% of the individuals encountering this syndrome have experienced pain. Such types of sensations have the tendency to arise after the removal of the body parts other than that of the limbs. The missing limb often feels shorter in length and the patient may feel as if the limb is in a painful position or in a distorted shape. Occasionally, the pain may be worsened by various external factors such as anxiety, stress and weather fluctuations. "Phantom limb" pain is often discontinuous, however, the frequency and intensity of the pain attacks usually decreases gradually with the passage of time. Phantom pains could also be experienced in slightly different sensations in individuals born without limbs or those who are already paralyzed. Upon regaining consciousness in the post operation period a large number of patients with such types of syndromes do not realize that their limb has been amputated (Ramachandran and Hirstein, 1998). The arms of the patient with "Phantom limb" feel the same from the inside as they were in their previous conditions, however, these limbs do not look the same on the outside(Cameron at al ,2002.p.84)(2). In spite of the progress made in the fields of medicines and surgery, there are times when someone's limb is so ruined by a disease or through an accident such that it must be amputated. In such a situation, the amputees continue to experience sensations from the limb that is no longer attached with the body of the patient. The neurological basis of the "Phantom limb" disorder mainly relies on the irritation in the severed nerve endings of the neurons called neuromas. The removal of the limb in "Phantom limb" syndrome leads to the termination of many nerve endings. The remaining nerve endings form the shape of a stump. The nerve ending are inflamed and considered to send irregular signals to the specific regions of the brain (Melzack, 1992.p.120) (3). Treatment: Many of the treatments based on the above given theory have generally failed. In+ extreme situations surgeons prefer a second amputation leading towards shortening of the stump of the body with the objective of removing the inflamed nerve endings of the limbs(Mishkin et al 1991.p.1857)(4). The treatments for "Phantom limb" include the use of drugs such as antidepressants for a short-term relief. However, spinal cord stimulation could be considered an effective treatment for the syndrome. Similarly, an electrical stimulator can be implanted under the skin of the patient and an electrode placed near the spinal cord of the body (Ramachandran, 1993.p.10413) (5). b. Anosognosia Anosognosia is a state in which a person who suffers from the disease seems unaware of or denies the presence of his or her disability. This includes unawareness of various dramatic impairments, like for example paralysis, blindness and other diseases (Hirstein &, William, 2004.p.148) (6). This syndrome was first named by Joseph Babinski in 1914, though little has been found about its cause and initial identification. Anosognosia is not related to cognitive flexibility, global mental disorder and confusion or other much bigger intellectual disturbances. The disorder does not appear to be directly linked to sensory loss and is considered to be caused by damage to neurocognitive processes which participate in integrating sensory information for supporting spatial or bodily representations. The disorder is thought to be linked to unilateral neglect, the position often noticed after damage to the right hemisphere of the cerebral cortex in which patients seem unable to attend to or comprehend anything on a specific side (usually the left side) of the their body(Adair et al ,1998.p.1903)(7). The brain-damaged patients perceive that a paralyzed or otherwise non-functional part of their body is working normally. In "Anosognosia", the patient is unaware of his/ her paralyzed limb and the condition appears to occur as the result of a lesion to the right hemisphere of the brain. The human brain consists of two parts, right hemisphere and left hemisphere, the paralysis is caused by damage in the left side of the body. However, the condition can appear to occur in union with other types of neurological impairment. The anosognosia could be selective in certain conditions such that if an affected person suffers from multiple impairments he or she may only be aware of one handicap and unaware of the others or vice versa. "Anosognosia" may sometime occur as a result of stroke which usually cuts off blood to the brain through the middle cerebral artery. The syndrome results from the unilateral neglect and as a result of damage to the non- dominant part of the brain that is the right hemisphere of the cerebral cortex. The sufferers are oftenly unable to attend to or to sometimes understand anything using a specific side of their body. "Anosognosia" has the probability of occurring as a part of language disorder, which causes a poor comprehension of speech or the delivery of speech with fluent words but in the shape of incomprehensible sentences. This condition is known as Werniicke’s aphasia. The patient in this case is not in a position to correct his/ her own phonetic errors and demonstrates anger and disappointments with the person to whom he / she is speaking. The term "anosognosia" is used to describe the lack of insight as shown by some people who suffer from the condition of psychosis. Three kinds of insights are associated with the anosognosia, and are most vulnerable to severe mental illnesses. These insights are associated with the impaired awareness. They include: a. Mental disorders among patients b. Existing medication effects c. Social consequences of existing mental disorders Treatment: Treatment of "Anosognosia" relates to the severity of the patient’s mental condition, severity of the mental illness, lack of awareness of the conditions associated with the medication, non-compliance and re-hospitalization of the patient. There are no long-term treatments for anosognosia. The patients are usually treated with cold water which is put into their left ear when the patient has a hearing problem. This is because ears function as gyroscopes in the human bodies. The fluid filled canals are lined with microscopic hairs that sense acceleration in the body and the information is transmitted through a set of nerves called a vestibular system. Cortices are responsible for letting our eyes track the moving objects. In this case the connection between parietal cortices and the vestibular system is of paramount importance for normal functioning of the human body. Majority of cases associated with anosognosia appear to disappear with the passage of time; however some other cases can last indefinitely. A significant number of cases of anosognosia which are long term are treated with cognitive treatment therapy with an objective to training the patient to adjust to their inoperable limbs. Explanation: Both these mental disorders that are the Phantom limb and "Anosognosia" have indicated the human dependence on the expectations which are learnt from their day to day activities against the dependence on the normal shapes that they encounter on their activities. This puts into consideration the functioning of the receptors found in the nervous system. The receptors are sensory nerves used for transferring messages in the shape of neuro-muscular combination with the use of chemicals to the central nervous system. The working of this system in a coordinated mechanism provides how we all perceive reality as our minds organize and cope in normal cases through the cognitive blitz in a coordinated mechanism. These disorders are outcomes of the general syndrome and also as a result of unilateral neglect. Some patients who suffer from stroke combined with injuries to the right side of their parietal cortex do not to distinguish anything especially if their left perceptual sphere has been affected. References: Halligan, P. & Berger, A. (1999). "Phantoms in the brain", British Medical Journal 319: 587–588. Halbert, J., Crotty, M. and Cameron, D. (2002). "Evidence for the optimal management of acute and chronic phantom pain: a systematic review", Clin J Pain 18 (2): 84–92. Melzack, R. (1992). "Phantom Limbs", Scientific American (April): 120–126. Retrieved from http://www.skidmore.edu/academics/biology/courses/ROY2/MindOnLine 2003b/LargeSizeArticles/PhanLimbEntire.pdf on 5th May 2010. Pons, T. et al. (1991). "Massive cortical reorganization after sensory differentiation in adult macaques", Science journal 252 (5014): 1857–1860. Ramachandran, V. (1993). "Behavioral and magnetoencephalographic correlates of plasticity in the adult human brain." Proc. Natl. Acad. Sci. 90: 10413–10420. Hirstein, W. (2004). Brain Fiction: Self Deception and the Riddle of Confabulation. MIT Press. pp. 148. Heilman, K. Barrett, M. and Adair J. (1998). "Possible mechanisms of anosognosia: a defect in self-awareness", Philosophical Transactions of the Royal Society B: Biological Sciences 353 (1377): 1903–1909.