MIRROR THERAPY IN STROKE REHABILITATION

Lidwina S. Sengkey Paola Pandeiroth

Bagian Ilmu Kedokteran Fisik dan Rehabilitasi Fakultas Kedokteran Universitas Sam Ratulangi Manado Email: [email protected]

Abstract: Paralysis in stroke is mainly caused by damage of any kind in internal capsule. Recovering of these damages require which involves parts of the brain survivors. One kind of therapies that has some beneficial effects on neuroplasticity is mirror therapy. This therapy is used to improve motor function after stroke. Mirror therapy is easy to set up and requires very little training without taxing the patient. Data obtained from several studies show that besides it is simple and cheap, this mirror therapy might have a significant effect on motor function and improve activities of daily living as an adjunct to the rehabilitation for stroke patients. This review aims to demonstrate the benefits of mirror therapy in stroke rehabilitation. Keywords: exercise therapy, mirror therapy, rehabilitation, stroke

Abstrak: Paralisis pada stroke terutama terjadi karena kerusakan di kapsula interna. Kerusakan ini memerlukan neuroplastisitas yang melibatkan sejumlah bagian otak yang selamat untuk memulihkannya. Salah satu terapi yang bermanfaat terhadap neuroplastisitas yaitu terapi cermin. Terapi ini digunakan untuk memperbaiki fungsi motorik pasca stroke. Terapi cermin mudah dilakukan dan hanya membutuhkan latihan yang sangat singkat tanpa membebani pasien. Data yang diperoleh dari beberapa penelitian memperlihatkan bahwa terapi cermin merupakan terapi yang sederhana, murah, dan efektif dalam memperbaiki fungsi motorik (baik ekstremitas atas maupun bawah) dan aktivitas kehidupan sehari-hari, sebagai tambahan untuk rehabilitasi yang umumnya dilakukan pada pasien dengan stroke. Telaah ini bertujuan untuk menunjukkan keuntungan terapi cermin pada rehabilitasi stroke. Kata kunci: terapi latihan, terapi cermin, rehabilitasi, stroke

Stroke is the leading cause of serious long- be the result mainly of irreversible damages term disability in adults. More than 60% of of the internal capsule.3 stroke survivors suffer from persistent Traditionally, a physical therapy for a neurologic deficits that impair their patient with hemiparesis in the weeks after activities of daily living.1 Paretic upper a stroke consists of an exercise therapy limb is a common and undesirable based on neuromuscular re-education. It consequence of stroke that causes activity has been shown that functional organi- limitation.2 It has been reported that up to zation of the motor system, including the 85% of the stroke survivors experience primary motor cortex, can be modulated by hemiparesis and that 55-75% have both ipsilateral limb movements and continued limitations in functioning their passive observation of movements of the upper extremities.2 After a stroke, lower- contra-lateral limb.4 Another alternative extremity motor function is often impaired, therapy is mirror therapy which was first causing restrictions in functional mobility.2 introduced by Ramachandran and Roger- Paralysis that follows a stroke is thought to Ramachandran to treat phantom after

84 Sengkey, Pandeiroth; Mirror Therapy in Stroke Rehabilitation 85 an . This therapy has been used Mirror therapy for the upper extremity to treat pain in amputee 5 The stroke survivor is seated and a patients, stroke patients, and etc. mirror is aligned to intersect with the Although patients often regain some of patient’s body in the sagittal plane at chest their lost function after therapy, most level. This is usually done by placing the remain chronically disabled. About 20% of mirror on the table with the hands resting these patients regain at least some part of on the table on either side of the mirror. their lost motor functions in the subsequent The reflective part of the mirror faces the months; thus, 50–60% are left with chronic unaffected side. As the patient looks into motor disorders. These motor impairments the mirror, all they see is the unaffected may substantially compromise the quality 6 side. The mirror blocks the view of the of life after stroke. It seems that there is a unaffected side of the body. The patient relationship between the amount of sensory gazes into the mirror reflecting the “good” impairment and the degree of motor hand. When the ‘good” hand is moved the recovery. mirror gives the illusion that the “bad” Somato-sensory function contributes hand is moving perfectly well. The stroke to performance of activities of daily living survivor attempts to copy the movement of following the stroke. This somato-sensory the “good” arm and hand to the hemiparetic loss is presents in more than 60% of people arm. Although the stroke survivor only sees with strokes; therefore, it is important that the reflection of the good hand, the rehabilitation interventions is aimed to the 8 6 movements look symmetrically (Fig. 1). sensory as well as the motor impairments.

DEFINITION OF MIRROR THERAPY Mirror therapy is a relatively new therapeutic intervention that focuses on moving the unimpaired limb. It is a form of imagery in which a mirror is used to convey visual stimuli to the brain through observation of one’s unaffected body part as it carries out a set of movements.4

PROCEDURE OF MIRROR THERAPY The general procedures of mirror therapy is the patient sits in front of a Figure 1. The patient’s affected arm is hidden mirror that is oriented parallel to his behind the mirror. While moving her midline blocking the view of the affected unaffected arm, the patient watches its mirror image as if it is the affected one. Source: Dohle limb which is positioned behind the mirror. 9 While looking into the mirror, the patient C et al., 2009. sees the reflection of the unaffected limb positioned as the affected limb. This arrangement is suited to create a visual Mirror therapy for the lower extremity illusion whereby movement of or touch to The stroke survivor can be either in the intact limb may be perceived as long sitting on a plinth or seated on a chair. affecting the paretic limb. After that, the The advantage of the plinth is that the patient involves performing movements of lower extremity is more easily viewed. The the unimpaired limb while watching its advantage of the chair is that it may be mirror reflection superimposed over the more comfortable for some patients. In (unseen) impaired limb.7 either case, a mirror is placed between the 86 Jurnal Biomedik (JBM), Volume 6, Nomor 2, Juli 2014, hlm. 84-90 patient’s legs to intersect his/her body in as follows: non-trivial contributions to the the sagittal plane facing the unaffected side. descending corticospinal tracts; more The patient is instructed to do plantar and bilateral control of movement than the dorsiflexion of the unaffected side ankle, motor cortex itself; and intimate connection and at the same time attempting to do the between premotor areas and visual input.12 same movement with the affected side. The As well as a number of neurological and speed of the movement is self-selected. For psychological levels, mirror therapy may both upper and lower extremities the help to reverse elements to the disused dosage is 30 minutes a day, and 5 days a affected limb.10 week for 4 weeks.8 The role of mirror therapy in influencing sensory impairments is still unclear. It might be caused by the visual MECHANISM OF MIRROR THERAPY input provided by the reflection of the The concept of mirror therapy has mirroris combined with the altered or been further substantiated neurophysio- absent sensation of the paretic hand via the logically. An imaging experiment demon- corpus callosum or via the activation of 5,13 strated that inversion of the visual image of mirror neurons. a hand can elicit lateralized cortical active- Another explanation is the advantage of mirror neurons discovered by Rizzolatti tion. In other words, when a right hand is 12 used, but perceived as a left hand, this leads et al. in the early 1990s. These neurons to an additional activation of the right are found in the frontal lobes as well as the hemisphere (and vice versa). The mirror parietal lobes. These areas are rich in motor provides patients with proper visual input - command neurons. Each of which fires to the mirror reflection of the moving good orchestrate a sequence of muscle twitches arm looks like the affected arm moving to produce simple skilled movement such correctly- and perhaps substitutes for the as: reaching a peanut, pushing a stone, or 9 putting an apple in to the mouth. A subset decreased or absent proprioceptive input. of these mirror neurons also fire when the Mental images of movement can be person merely watches another individual generated independently of overt beha- performing the same movement. Mirror vioral output of a paretic limb. Humans are neurons necessarily involve interactions equipped with a simulation network that among multiple modalities (vision, motor positions the motor system in anticipation commands, and ) which of movement execution and provides suggest that they might be involved in the themselves with information about the efficacy of mirror therapy in stroke.3 possibility and meaning of up coming Stroke paralysis results partly from actions. The processes underlying motor actual permanent damages in the internal imagery are similar to those that are active capsule. An additional possibility is that during actual movement. Actions generated lesion is not always complete; there may be by using motor imagery adhere to the same a residue of mirror neurons that have rules and constraints that physical survived but are dormant or their activity is movements follow. The neural network inhibited and does not reach the threshold. involved in motor imagery and in motor So, mirror therapy might owe part of its execution overlap each other, primarily in efficacy to stimulates these neurons, thus the premotor and parietal areas, basal providing the visual input to revive the 10 ganglia, and cerebellum. motor neurons.3 The use of a mirror may recruit the premotor cortex to motor rehabilitation.11 RESULTS OF STUDIES IN MIRROR The premotor cortex has a number of THERAPY features suggesting that it might possibly be a link from the visual image in the Dohle et al.9 evaluated the effect of a mirror to motor rehabilitation after stroke therapy that included the use of a mirror to Sengkey, Pandeiroth; Mirror Therapy in Stroke Rehabilitation 87 simulate the affected upper extremity with Yavuzer et al.2 evaluated the effects the unaffected upper extremity early after of mirror therapy on upper-extremity stroke. There were 36 patients with severe motor recovery, spasticity, and hand- hemiparesis caused by the first-ever related functioning of inpatients with ischemic stroke in the territory of the subacute stroke. Their study design was middle cerebral artery not more than 8 randomized, controlled, assessor-blinded, weeks after the stroke. They completed a 4-week trial, with follow-up at 6 months. protocol of 6 weeks of additional therapy There were a total of 40 inpatients with (30 minutes a day, 5 days a week) with stroke (mean age 63.2 years), all within 12 random assignment to either mirror therapy months post stroke. The intervention they or an equivalent control therapy. The main did was 30 minutes of mirror therapy outcome measures were the Fugl-Meyer program a day consisting of wrist and subscores for the upper extremity, finger flexion and extension movements or evaluated by independent raters through sham therapy in addition to conventional videotapes. Patients also underwent stroke rehabilitation program, 5 days a functional and neuropsychological tests. week, 2 to 5 hours a day, for 4 weeks. The This study showed that at the beginning of measurement of outcome was conducted by the therapy in the subgroup of 25 patients the Brunnstrom stages of motor recovery, with distal plegia, mirror therapy patients spasticity assessed by the Modified regained more distal function than control Ashworth Scale (MAS) and hand-related therapy patients. Furthermore, across all functioning (self-care items of the patients, mirror therapy improved recovery Functional Independence Measure (FIM) of surface sensibility. Neither of these instrument). The results showed that the effects depended on the side of the lesioned scores of the Brunnstrom stages for the hemisphere. It is concluded that mirror hand and upper extremity and the score therapy early after stroke was a promising of FIM self-care improved more in the method to improve sensory and attentional mirror group than in the control group deficits, and to support motor recovery in a after 4 weeks of treatment (P < .01) and distal plegic limb. at the 6-month follow-up (P < .05). No According to Stevens and Stoykov10 significant differences were found between in rehabilitation for hemiparesis, one of the the groups for the MAS. It was concluded goals of an occupational therapist was to that in the group of subacute stroke practice upper extremity tasks with the patients, hand functioning improved better recovering individual. The practice was after mirror therapy in addition to a intended to strengthen muscles and refine conventional rehabilitation program movements. It also provided examples for compared with a control treatment the recovering body and brain as they immediately after 4 weeks of treatment attempted to re-establish their delicate and at the 6-month follow-up, whereas cognitive and neural connections mediating mirror therapy did not affect spasticity.2 voluntary behavior. They outlined a Kuys et al.15 studied the effects and method for simulation of movement by adherence of mirror therapy among people using a mirror. The simulation provided a with chronic upper limb hemi-paresis. compelling perceptual experience of Participants of 12 people with chronic bilateral motion beyond the current hemiparesis underwent a 30-minute- capabilities of the affected limb. A 3-week sensorimotor mirror therapy home-based course of the simulation practice revealed exercise program 3 times a week for 6 improved function as demon-strated by weeks. The compliance with the program increases in Fugl-Meyer scores and faster and the effect on sensory outcomes were movement speeds as demon-strated by determined. Light touch threshold and decreased movement times for the Jebsen proprioceptive error, upper limb activity test of hand function.14 limitations, and participation restrictions 88 Jurnal Biomedik (JBM), Volume 6, Nomor 2, Juli 2014, hlm. 84-90 were measured at baseline (week 0), affected upper extremity using three immediately after week 6, and 6 weeks different conditions: 1) relaxation; 2) real following the intervention (week 12). mirror; and 3) virtual mirror. Moreover, Compliance with the program was fair, and they compared the MEPs from the virtual 66% of supervised and 62% of unsuper- mirror paradigm using continuous visual vised sessions were completed. The paretic feedback or intermittent visual feedback. hand performed worse compared to non- The result stated that the rates of amplitude paretic hand at baseline with no difference increment and latency decrement of MEPs in sensory measures demonstrated over in both groups were higher during the time. Activity limitations and participation virtual mirror task than during the real restrictions improved by week 12 (P mirror. In healthy subjects and stroke <0.05). This sensorimotor mirror therapy patients, the virtual mirror task with home-based exercise program showed little intermittent visual feedback significantly improvement in light touch threshold and facilitated corticospinal excitability of proprioception that appeared to be func- MEPs compared with continuous visual tionally important for this group of people feedback.16 with chronic hemiparesis. Mirror therapy may be a useful tool for clinicians, particu- larly for patient with independent use. OUR EXPERIENCE IN MIRROR Youn et al.16 carried on a study to THERAPY delineate the changes in corticospinal excitability when individuals were asked to Sengkey and Pandeiroth (2008) exercise their upper extremity using a real studied the comparison between exercise mirror and virtual mirror (Fig. 2). therapy and exercise therapy with mirror on Moreover, they attempted to delineate the the lower limb functional motoric recovery role of visual modulation within the virtual in post stroke patients ≤ 1 year in Prof. Dr. environment that affected corticospinal R.D. Kandou General Hospital (Figure 3). excitability in healthy subjects and stroke This was a quasi experimental study with a patients. pretest and posttest control group design. There were a total of 18 healthy There were 24 patients aged 40-65 years subjects and 18 hemiplegic patients who received 15 minutes exercise therapy enrolled in their study. Motor evoked sessions 3 times a week for 4 weeks. potential (MEPs) from transcranial Randomly, 12 patients were assigned for magnetic stimulation were recorded in the the exercise therapy and the other 12 flexor carpiradialis of then on dominant or patients for exercise therapy with mirror.

Figure 2. Setup of the real mirror (A) and virtual mirror (B) experiments. Source: Youn JK, et al., 2012.16 Sengkey, Pandeiroth; Mirror Therapy in Stroke Rehabilitation 89

CONCLUSION Mirror therapy is an alternative therapeutic intervention that focuses on moving the unaffected limb to convey visual stimuli to the brain through observation of those movements in a mirror. This observation may recruit the premotor cortex to motor rehabilitation of the affected parts of the brain. Studies showed promising results of this therapy in improving sensory and Figure 3. Mirror therapy on the inferior motor function following stroke. extremity of a male patient with stroke at Mirror therapy is an alternative Rehabilitation Department Prof. Dr. R.D. therapeutic intervention that focuses on Kandou General Hospital. moving the unaffected limb by using a mirror to convey visual stimuli to the brain through observation of one’s unaffected The lower limb motoric recovery was body part as it carries out a set of assesed by using the Brunnstrom Stages movements. The use of a mirror may before and after exercise (tested by recruit the premotor cortex to motor Wilcoxon signed ranks). There was a rehabilitation. Studies showed a promising significant increase of the Brunnstrom results of mirror therapy by improving Stages (P <0.01). Moreover, the Brunnstrom sensory and motor function following Stages that were tested by using paired T stroke. test before and after exercise therapy with mirror also stated a significant increase (P REFERENCES <0.01). The Mann-Whitney U test for the 1. Hummel F, Celnik P, Giraux P, Floel A, Brunnstrom stages of these two groups Wu W, Gerloff C, et al. Effects of showed that the mean rank of exercise non-invasive cortical stimulation on group was 10.0 while of mirror therapy skilled motor function in chronic group 15.0 with P <0.05. This indicated stroke. Brain. 2005;128:490-9. 2. Yavuzer G, Selles R, Sezer N, Sutbeyaz S, that the exercise therapy with mirror was Bussmann JB, et al. Mirror therapy better than the exercise therapy alone. improves hand function in subacute For Functional Independence Measure stroke: a randomized controlled trial. (FIM), the score of motoric before and after Arch Phys Med Rehabil. 2008;89:393-8. given exercise therapy increased from 43,0 3. Ramachandran VS, Altschuler EL. The to 54,5 which mentioned a significant use of visual feedback, in particular recovery of motoric functional (P <0,01). mirror visual feedback, in restoring brain function. Brain. 2009;132:1693- For exercise therapy with mirror, the score 1710. of FIM before and after mirror therapy 4. Sütbeyaz S, Yavuzer G, Sezer N, Koseoglu increasing from averagely 63,3 to 75,3. F. Mirror therapy enhances Lower- These results showed that the functional Extremity Motor Recovery and Motor recovery produced by both therapies were Functioning After Stroke: A significant, but the FIMs of both groups Randomized Controlled Trial. Arch Phys Med Rehabil. 2007;88:555-9. were not different significantly (P >0.05). 5. Ramachandran VS, Rogers-Ramachandran It is concluded that exercise therapy with D. Synaesthesia in Phantom Limbs mirror may improve lower limb functional Induced with Mirrors. Proceedings: recovery in post stroke patients. Biological Sciences. 1996;263:377-86.

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