Mirror Therapy - Research Paper Example

Mirror Therapy Mirror Therapy Introduction As the life expectancy increases in the post-industrial world, health care professionals across the globe face the health issues concerned with the ageing of the population. Stroke and subsequent rehabilitation of paralyzed limbs create a tough challenge, particularly if complicated by severe sensory impairment. Phantom limb pain (PLP) that occurs as an implication of amputation represents a similar case since no effective approach to its management has been introduced yet. Mirror therapy (MT), a method that relies on the visual reproduction of motion in the affected extremity or stump by moving the healthy limb before the mirror, is likely to be the key to solution of the two major problems as there are numerous reports of its effective application. Invention of Mirror Therapy MT was first introduced in 1996 by Dr. V.S. Ramachandran, Professor of the Psychology Department at the University of California, San Diego. Having obtained a Degree in Medicine, Ramachandran proceeded with education to acquire a Ph.D. at the University of Cambridge. Although his early research focused primarily on the patterns of visual recognition, his most significant contribution are probably his works in the field of behavioral neurology. In collaboration with Rogers-Ramachandran, he designed the MT method hoping to find the cure for what is known as a ‘learned paralysis’ and help those suffering from chronic pain in the amputated extremity (Ramachandran & Blakeslee, 1998). The visual input from contemplating the mirror reflection of the undamaged limb instead of the stump enabled patients to perceive motion in the phantom extremity. The researchers hypothesized that each time a person intends to make a move with the paralyzed arm their brain receives both sensory and proprioceptive input that the extremity has not changed the position. The impulse then integrates into the cortex circuitry via the mechanism of Hebbian learning. Although the arm is missing, the brain “remembers” it being paralyzed. To reprogram the brain and, therefore, remove the palsy, the scholars invented the Mirror box. Principles of MT For an effective session of MT, one must employ a Mirror box. The Mirror box features two mirrors incorporated in the center of it. The patient puts an intact limb on one side of the Mirror box and the injured one on another. Subsequently, he is supposed to observe the health extremity in the mirror and perform "mirror symmetric" motions, similar to those that a music director conducts or simply clap his or her hands. Since the patient sees the reflection of a healthy arm moving, it is perceived as if the affected limb moves simultaneously. Receiving such artificially created visual feedbacks, he or she gets the opportunity to change the imaginary position of the injured arm and locate it more comfortably. The approach grounds on the brain’s inclination to place visual input over proprioceptive or sensory when analyzing the extremity position. The efficient utilization of this principle should theoretically bring positive results in the treatment of many conditions including stroke, amputation, and PLP. MT has also been proven effective in raising spinal and cortical motor excitability, supposedly via its impact on the mirror neuron system. Nearly 20% of all neurons in the brain are Mirror Neurons (Diers et al, 2010). The principal function of this type of neurons is laterality reconstruction – the conscious discrimination between the sides. When applying the Mirror box, the mirror neurons become activated, and this facilitates the rehabilitation of injured limbs. The method relies on the observation of motion that triggers the motor mechanisms that would normally be enrolled in that movement. Parallels are drawn with motion imagery, where, instead of watching a movement reflection in the mirror, one reproduces it in mind. However, it is considered that the brain’s natural predisposition to regard visual information over any other type of input automatically makes MT a more promising technique, regardless of the yet insufficient clinical evidence in support of this hypothesis. It must be emphasized that the major difference of the Mirror box strategy in comparison to the more conventional methods is that the MR stimulates the ipsilateral hemisphere to establish connections with the injured limb on the same side and does not activate the contralateral hemisphere. Effects of MT on Amputations PLP is a hurtful sensation that is felt in a body part that has been removed. This type of pain was first diagnosed in the 16th century by a French physician Ambrose Pare (Ramachandran & Blakeslee, 1998). Since then, a considerable number of scientists attempted to reveal its pathophysiological background. However, its etiology and pathology have not yet been fully decoded. It is known that 50 to 80% of limb amputations are followed by PLP. About 75% of the patients develop PLP within the first few days after the limb removal, though, the pain may also appear immediately after the amputation (Heyes et al, 2004). The intensity of the pain, as well as frequency can reduce with time. Nonetheless, cases where no improvement or even a deterioration of symptoms are observed are not a rarity (Nikolajsen et al, 2007). The traditional treatment options of PLP include neuromodulation, nerve blockage, physiotherapy, and medicamentous treatment. None of the methods has been proven efficient enough, which lives much space for alternative tools such as MT. The efficacy of MT may vary as it depends on the pain type. Reportedly, the method is associated with better results if used in management of deep somatic pain (e.g., proprioceptive pain), while it has only a moderate impact on superficial pain (e.g., nociceptive pain). This happens because the deeper lying tissues integrate sensorimotor fibers and produce movements, which is not a feature of superficial tissues (Sumitani et al, 2008). Chan et al (2007) distributed 22 patients suffering from PLP into three groups: mental imagery group, mirror therapy group, and control group. After a while, all of the patients from the mirror therapy group reported that the pain has alleviated. The members of the two other groups demonstrated no improvement. However, the power of evidence is weakened by a poor description of research methodology. In 2010, Diers et al concluded that using MT as a part of Graded Motor Imagery (GMI) produces better results than its isolated application. In a randomized clinical trial, patients with PLP showed notable decrease in pain and significant functional improvement both immediately after the course and after six months when MT was used as a part of GMI. On the contrary, isolated use of mirrored imagery was unsuccessful in PLP patients. The researchers assumed that further investigation was necessary to identify the cortical mechanisms underlying motor imagery and MT in order to establish the optimal approach. MT and Stroke Recently, MT has been used not only in management of PLP but also to cure strokes (Ezendam et al, 2009). A stroke is a morbid condition that develops when the flow of oxygenated blood to a certain part of the brain is insufficient to maintain its normal function. Exposed to oxygen shortage, neurons die within few minutes. Sudden haemorrhage into the brain causes another type of stroke known as haemorrhagic stroke. The onset of stroke is typically abrupt; it usually takes seconds to minutes for the symptoms to develop, and, in most cases, they do not progress further. Clinical manifestation depends on which portion of the brain has suffered. Usually, the size of lesion is directly related with the severity of symptoms. Up to 75% of stroke patients suffer from a subsequent disability (Coffey, 2001). Stroke affects people both mentally and physically. The prognosis varies broadly depending on location and size of the injury, and dysfunction corresponds to the affected area of the brain. Some of the common physical disabilities caused by stroke are numbness, plegia or paresis, muscle weakness, pain, apraxia, and urinary incontinence. If the stroke is extensive or affects certain locations such as the medulla oblongata, it may cause coma or lead to fatal consequences. MT has been used successfully in rehabilitating stroke patients. Clinical trials that combined MT with traditional rehabilitation displayed the most remarkable outcomes (Moseley, 2006). Nevertheless, there is no single opinion regarding its efficacy. Current evidence implies that MT can only be applied effectively for upper extremity treatment. In a 2012 Cochrane Review Thieme et al analyzed the effectiveness of MT for improving routine activities, motor function, and mitigating pain. 14 studies that involved 567 participants and compared MT with other techniques were evaluated. In the end of the course, movement in the affected was improved and the pain reduced significantly. Conclusion MT is an alternative non-medicamentous treatment technique that is currently being evaluated as a stand-alone option for managing stroke and PLP. It is a rehabilitation strategy developed to reconstruct motor mechanisms. When applying this method, patients conduct motions with the unaffected limb while observing its reflection in the mirror. As the injured extremity is hidden inside the box directly behind the mirror, this creates an illusion and notifies the motor cortex of the movement in that extremity, although it hasn’t occurred. The approach grounds on the brain’s predisposition to prioritize visual input over sensory or motor. MT offers physicians an easily applicable adjuvant tool. However, its efficacy as a self-contained technique is based predominantly on low quality evidence. Alternatively, there is ample evidence in support of its successful utilization as a component of GMT. References Chan, B., Witt, R., & Charrow, A. (2007). Mirror therapy for phantom limb pain. The New England Journal of Medicine, 357, 2206–2207. Coffey, C. (2001). The American Psychiatric Press textbook of geriatric neuropsychiatry. Washington, DC: The Press. pp. 601–617. Diers, M., Christmann, C., Koeppe, C., Ruf, M., & Flor, H. (2010). Mirrored, imagined and executed movements differentially activate sensorimotor cortex in amputees with and without phantom limb pain. Pain, 149(2), 296-304. Ezendam, D., Bongers, R., & Jannink, M. (2009). Systematic review of the effectiveness of mirror therapy in upper extremity function. TIDS Disability & Rehabilitation, 31, 1-15. Hayes, C., Armstrong-Brown, A., & Burstal R. (2004). Perioperative intravenous ketamine infusion for the prevention of persistent post-amputation pain: a randomized, controlled trial. Anaesthia and Intensive Care Journal, 32, 330–338. Moseley, G.L. (2006). Graded motor imagery for pathologic pain: a randomized controlled trial. Neurology, 67, 2129–34. Nikolajsen, L., Ilkjær, S., Krøner, K., Christensen, J., & Jensen, T. (2007). The influence of preamputation pain on postamputation stump and phantom pain. Pain, 72, 393-405. Ramachandran, V., & Blakeslee, S. (1998). Phantoms in the brain: Probing the mysteries of the human mind. New York: William Morrow. Sumitani, M., Miyauchi, S., Mccabe, C., Shibata, M., Maeda, L., Saitoh, Y., . . . Mashimo, T. (2008). Mirror visual feedback alleviates deafferentation pain, depending on qualitative aspects of the pain: A preliminary report. Rheumatology, 47, 1038-1043. Thieme, H., Mehrholz, J., Pohl, M., & Dohle, C. (2012). Mirror therapy for improving motor function after stroke. Cochrane Database of Systematic Reviews Protocols. Read More