Mirror Therapy Efficacy in Upper Limb Rehabilitation Early After Stroke
Condition: Stroke, Acute
MeSH terms: Stroke
Study type: Interventional

Summary: 
      This study evaluates the effects of mirror therapy on upper-limb motor impairment in stroke
      patients early after their cerebrovascular accident. In recent years mirror therapy has been
      used in stroke rehabilitation, both to ease motor (e.g., upper limb impairment) and cognitive
      (e.g., spatial neglect) recovery. To note, mirror therapy is a simple and inexpensive
      treatment that patients can practice independently and with no significant side effects.
      However, a recent review concluded that the currently evidence available is not enough to
      determine about the actual effectiveness of mirror therapy in stroke survivors. Moreover, at
      our knowledge, the majority of studies recruited chronic stroke patients while only a few
      trials recruited patients within few weeks after stroke. Therefore, further research is
      encouraged particularly early after stroke.

      In mirror therapy patients exercise their sound hand while it is reflected by a mirror placed
      at right angle to the patient's trunk. With this gambit, patients see two hands moving: their
      sound hand (i.e., the hand that is voluntarily moved) and the "avatar" of their impaired hand
      (i.e., the sound hand reflection in the mirror). In this assessor-blinded, randomized
      controlled trial half of participants receive mirror therapy .The other half receive sham
      therapy, in which the mirror is flipped so that the opaque surface face the sound arm. Mirror
      therapy and sham therapy are added to conventional rehabilitation.

      In the current work, we investigate the efficacy of mirror therapy on upper-limb recovery in
      early post-stroke patients.
    

Detailed description: 
      An assessor blind, randomized controlled study was conducted in the Casa di Cura Del
      Policlinico (CCP), an inpatient rehabilitation clinic in Milan. Stroke patients were referred
      to the study by their physician during their inpatient stay.

      In addition to the intervention or control treatment, all patients participated to a
      conventional rehabilitation program consisting of physiotherapy (45 minutes per session,
      twice daily, five days per week) and occupational therapy (45 minutes per session, once a
      day, two to five days per week according to the physician prescription). Speech and language
      therapy and neuropsychological therapy were provided as needed. All treatments were one on
      one sessions.

      Patients were measured at baseline and after five weeks, when treatments end. The assessors
      were blinded to group allocation.

      Eligible patients were randomly assigned to either the intervention group or the control
      group. We used block randomization so that the number of participants was similar in the two
      groups (four patients per block, 1:1 ratio). A computer generated the randomization list and
      when a new eligible patient was recruited, a researcher contacts the person that allocate
      patient in mirror therapy or sham therapy group according to the randomization list. Patients
      were unaware of the group assignments (intervention vs. control) and of the alleged active
      treatment. All patients gave their informed written consent to participate in the study.

      Patients of the intervention group received mirror therapy and patients of the control group
      received sham therapy, added to a conventional rehabilitation program. During mirror therapy,
      the patient was sitting on a conventional chair and placed her/his forearms on a table. A
      mirror (45 cm × 40 cm) was positioned between the two arms, at right angle with the patient's
      trunk. The reflective surface was oriented so that the participant could easily see the
      mirror image of his/her sound arm. During sham therapy, the mirror was flipped so that the
      opaque surface faced the sound arm.

      Intervention and control group patients exercised the very same movements. In particular,
      movements were organized into three classes (simple, complex and functional movements).
      Examples of simple movements are the flexion-extension of the elbow with the pronated forearm
      or flexion-extension of the wrist. Complex movements were simple movements performed with the
      elbow flexed at 45° or simple movements performed with the elbow flexed at 45° and lifted
      from the table. Functional movements consisted in reaching, grasping and moving or using
      different objects (e.g., a pen, a tennis ball, a coin) Patients were asked to move their
      sound arm while looking the mirror reflective surface (intervention group) or the opaque
      surface (control group). Patients were also asked to stay still with the impaired arm.

      Both mirror therapy and sham therapy consisted in one on one sessions (one therapist treated
      one patient), lasting 30 minutes each and administered once daily, five days per week for 30
      days. From day 1 to 10, from day 11 to 20 and from day 21 to 30, patients practiced simple,
      complex and functional movements, respectively. In each session, ten different movements were
      practiced. Mirror therapy and sham therapy were administered in a quiet room close to the
      rehabilitation gym.

      The study was powered to detect a clinically important difference of the main outcome. Sample
      size was calculated choosing a large effect size (Cohen's d = 0.9) and type 1 and type 2
      error probabilities equal to 0.05 and 0.2, respectively. These parameters return a total
      sample size of 40 patients (13). Therefore, we planned to recruit 20 patients in each
      treatment group.

      Counts, mean and standard deviation (SD) were used as descriptive statistics. Differences
      between the baseline characteristics of the intervention and control groups were tested using
      the two sample t-test and the Fisher's exact test (nominal data). The 0.95 confidence
      interval (0.95 CI) for matched samples was used for comparing the main and secondary outcomes
      before baseline and at week five (within group difference). The 0.95 CI for independent
      samples was used for testing differences in the main and secondary outcomes between the
      intervention and the comparison groups (mirror therapy vs. sham therapy, between groups
      difference).

      A type 1 error probability equal to 0.05 was chosen. An intention-to-treat analysis was
      performed using the last observation carried forward method. In addition, the significance
      analysis was repeated after drop out removal. Statistical analyses were done in R 3.3.0 (R: A
      Language and Environment for Statistical Computing) with the ggplot and cowplot packages.
    

Intervention name(s): Mirror therapy
Intervention type(s): Other
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Stroke; rehabilitation; mirror therapy; upper limb