CRITICALLY APPRAISED PAPER (CAP) FOCUSED QUESTION To what extent do the effects of neuromuscular electrical stimulation (NMES) on motor recovery of the upper extremity after stroke persist after the intervention ends? Lin, Z., & Tieben, Y. (2011). Long-term effectiveness of neuromuscular electrical stimulation for promoting motor recovery of the upper extremity after stroke. Journal of Rehabilitation Medicine, 43, 506 510. http://dx.doi.org/10.2340/16501977-0807 CLINICAL BOTTOM LINE: Stroke continues to be one of the leading causes for disabilities and death among adults. Treatment of strokes costs the United States an estimated $54 billion annually (Heindenreich et al., 2011). The time for recovery of arm function in patients with stroke is variable, and delay in recovery increases the risk of secondary complications, such as spasticity, pain, and contractures. Along with the conventional therapy, inclusion of neuromuscular electrical stimulation (NMES) in the course of therapy is being widely researched (De Kroon, Van der Lee, Ijzerman, &Lankhorst, 2006). In this randomized, controlled, single-blinded trial, the authors demonstrate that compared to the standard rehabilitation protocol, NMES with standard rehabilitation intervention promotes improved muscle strength and motor function in the affected extremity. Use of NMES shows improvement in shoulder and wrist function and thereby improves participation in activities of daily living (ADLs) after an individual s first stroke. The study also demonstrates retention of the benefits for at least 6 months.the sample size in the study involved Chinese stroke survivors; however, the findings could be generalized due to the well-defined inclusion and exclusion criteria. This article gives us an opportunity to gain insight into the potential for using NMES as a productive adjunct when incorporated into broader occupational therapy programs. RESEARCH OBJECTIVES: The primary objective was to investigate the effects of neuromuscular electrical stimulation to the affected upper extremity (UE) of patients with stroke to improve motor function. 1
The secondary objective was to find the duration of persistence of effects of NMES on the affected UE. The objectives of this study address the focal question by demonstrating the effects of NMES on motor recovery and thereby an increase in participation in ADLs poststroke. DESIGN TYPE AND LEVEL OF EVIDENCE: Level 1b Homogenous group with randomized allocation of participants into experimental and control groups Limitations: Absence of sham NMES group to compare the placebo effects of NMES. SAMPLE SELECTION: How were subjects selected to participate? Please describe. The subjects were Chinese stroke survivors ages 44 to 80 years, who were admitted to the Department of Neurology and Rehabilitation Medicine of the fifth affiliated hospital of Sun Yatsen University January to August 2008. Patients were excluded from the study if their score on abbreviated mental test was lower than 7. Inclusion Criteria: First stroke, within 3 months after onset, admitted to the Department of Neurology and Rehabilitation Medicine of the fifth affiliated hospital of Sun Yat-sen University January to August 2008. Diagnosed with either cerebral infarction or cerebral hemorrhage using either computed tomography or magnetic resonance imaging, fulfilling the diagnostic and classification criteria for stroke established by the Chinese Neuroscience and Neurosurgery Institute. Participants were ages 44 to 80 years, with hemiplegia of one upper limb; shoulder flexor strength before intervention was grade 3 or less. Exclusion criteria: Patients with progressive stroke or subarachnoid hemorrhage Shoulder muscle strength grade 3 Severe heart, liver, kidney or infectious disease, head injury, tumor A score <7 on the abbreviated mental test Patients younger than age 44 years, older than age 80 years, or those not willing to sign the consent form. SAMPLE CHARACTERISTICS: N = 46 # (%) 9 (15.2%) with 19 subjects in the intervention group and 18 in the Dropouts: control group remaining at the end of the study. 2
#/ (%) Male 22 (59.45%) #/ (%) Female 15 (40.54%) Ethnicity Chinese Disease/disability diagnosis cerebral infarction or cerebral hemorrhage Check appropriate group size: <20/study 20 50/study group 51 100/ study group 101 146/study group 150 200/study group Sample characteristic bias: None, there were no significant differences in age, gender, or stroke type (i.e., cerebral infarction, cerebral hemorrhage) between the two groups. Were the reasons for the dropouts reported? Yes, 7 patients dropped out due to early discharge and 2 patients due to illness. INTERVENTION AND GROUP COMPARISONS: Note. Included are only those interventions relevant to answering the evidence-based question. Group 1: Intervention group Brief description Setting Who delivered? Frequency Duration The intervention group received NMES as well as standard intervention, including physical therapy and occupational therapy. The surface electrodes were applied over the motor points near the middle of the supraspinatus muscle and the deltoid muscle on the paretic side, as well as over the wrist extensors (between one-third and half-way from the proximal end of the dorsal forearm). The stimulation was at a frequency of 30 hz, with a pulse width of 300 μs, and ramp up and down times of 1 s each. Amplitude was adjusted to a comfortable level to elicit shoulder abduction of approximately 30 50 degrees and full wrist extension. Patients actively focused on the movement induced by NMES during the intervention. Department of Neurology and Rehabilitation Medicine of the fifth affiliated hospital of Sun Yat-sen University. Physical therapists (different from those assessing the outcome measures). 30 min per day, 5 days per week, for 3 weeks for NMES and 30 min each of physical therapy and occupational therapy, 5 days per week for 3 weeks. 3 weeks. Group 2: Control group Brief description Setting The control group received conventional physical therapy and occupational therapy. Department of Neurology and Rehabilitation Medicine of the fifth affiliated hospital of Sun Yat-sen University. 3
Who delivered? Frequency Duration Physical therapists (different from those assessing the outcome measures). 30 min each of physical therapy and occupational therapy, 5 days per week for 3 weeks. 3 weeks. Intervention Biases: Contamination: Yes/ No The patients were randomly divided into NMES group or control group after stratification using a minimizing software, which is a computer program for randomizing patients with near-even distribution of important parameters. Co-intervention: Yes/No Both the intervention and control group received conventional physical therapy and occupational therapy, making it difficult to identify the effects of therapy from the effects of NMES. Timing: Yes/No The patients included in the study were within 3 months post onset. All patients received the same standard intervention, including physical therapy and occupational therapy for 30 min per day for 5 days per week for 3 weeks. In addition to this conventional therapy, the NMES group received NMES for 30 min a day for 5 days a week for 3 weeks. The timing of the study did not favor any particular group. The study was carried out January to August 2008. Site: Yes/No The site of the study was consistent amongst both the groups. The entire study was carried out in Department of Neurology and Rehabilitation Medicine of the fifth affiliated hospital of Sun Yatsen University. Use of different therapists to provide intervention: Yes/No There is a possibility of intervention bias due to the study being single blinded, because the therapists delivering intervention were aware of group allocation. MEASURES AND OUTCOMES: Name of measure, what outcome was measured, whether the measure is reliable and valid (as reported in article yes/no/nr [not reported], and how frequently the measures were used. 1. Modified Ashworth Scale (MAS) was used to evaluate shoulder spasticity. Reliability: Yes, but not specified in this study. Validity: Yes, but not specified in this study. Frequency: Measured before initiating the intervention and after the 2nd and 3rd week of intervention. The intervention was then discontinued for both groups, and the 4
assessments were repeated 1, 3 and 6 months post intervention. 2. Upper Limb section of the Fugl-Meyer Assessment (FMA U) was used to evaluate and measure sensory motor recovery and functional mobility in poststroke hemiplegia patients. Reliability: Yes, but not specified in this study. Validity: Yes, but not specified in this study. Frequency: Measured before initiating intervention and after the 2nd and 3rd week of intervention. The intervention was then discontinued for both groups, and the assessments were repeated 1, 3 and 6 months post intervention. 3. Modified Barthel Index (MBI) was used to assess the overall functional independence after the stroke. Reliability: Yes, but not specified in this study. Validity: Yes, but not specified in this study. Frequency: Measured before initiating intervention and after the 2nd and 3rd week of intervention. The intervention was then discontinued for both groups, and the assessments were repeated 1, 3 and 6 months post intervention. Measurement Biases: Masking/blinding of evaluators: Yes/No The study was single blinded, so subjects were blinded to the allocation to intervention or control group, but the therapists delivering standard intervention and NMES were aware of group allocation, possibly affecting intervention. However, the therapists who assessed the subjects for outcome measures were blinded to the group allocation. Recall or memory bias: Yes/No This study did not involve outcomes measured using self-report tools, surveys, or interviews on the basis of recall of past events. Others: Measurement bias may be possible as the outcome measures were assessed by physical therapists and they may not have precise training in the assessment of ADLs. RESULTS: FMA U scores significantly increased in both the groups toward the end of the 2nd and 3rd week of intervention; however, patients in the NMES group, on average, showed significant enhancement in shoulder and hand functions. These were consistently better than the mean improvements in the control group over the entire 6 months (p < 0.05). Favorable improvement was seen in the experimental group for the MAS score at the 3 rd week and 1 month post intervention (p < 0.05). However, this effect was found to be wearing off and disappeared at the 3- and 6-month follow-up assessments. The MBI scores for the experimental group were significantly improved at 1, 3, and 6 months after intervention (p < 0.05), implying that participants in NMES group demonstrated greater independence while participating in the ADLs. 5
Was this study adequately powered? Yes, the experimenters calculated sample size before recruitment of participants for the study and identified 46 subjects who met the inclusion criteria. Were appropriate analytic methods used? Yes, more than one outcome measure was assessed that involved different types of variables, therefore Multiple analysis of variance (MANOVA) was used to compare the outcomes for the 2 groups before intervention, after the 2nd and 3rd week, and 1, 3, and 6 months post intervention. χ2 and Kruskal Wallis tests were used to identify significant differences in age, gender, or nature of stroke between the 2 groups. Were statistics appropriately reported? Yes, tabular representation of the data clearly communicates information about the demographics and scores of the Upper Limb section of the FMA U, MAS for Spasticity, and MBI of both the groups before the intervention and their comparisons during the course of the study. CONCLUSIONS: This study found that NMES intervention during early rehabilitation significantly improved motor function in the hemiplegic UE of stroke patients and enhanced their ability to perform ADLs due to the improvement in motor function in the affected UE. The higher FMA U, MAS, and MBI scores indicate that addition of NMES to conventional therapies enhances recovery compared to conventional therapy alone. Due to current financial constraints on the health care system, this study serves as an important evidence to enhance recovery in the stroke survivors. We strongly support the American Occupational Therapy s (2008) position statement that exclusive use of physical agent modalities such as electrical stimulation is not occupational therapy and that modalities should be used as a preparatory method for therapeutic use of occupations or purposeful activities (p. 691). Were the conclusions appropriate for the Study Design (Level of Evidence)? Yes, this study is a Level 1, randomized controlled trial, which draws comparison between the NMES group and the control group and tests the effectiveness of NMES post first stroke. Outcomes were measured using a variety of tests at six different points in time. Were the conclusions appropriate for the statistical results? Yes, the study projects the conclusions derived from the statistical results. Were the conclusions appropriate given the study limitation and biases? Yes, the conclusions are appropriate taking into consideration the absence of sham stimulation group, and the patient clientele comprising of only Chinese population. Absence of sham stimulation group: Although the study design lacked a sham group, the participants were aware that they participated in an experiment. Therefore even though 6
the subjects were not tested for placebo effects, they possibly performed at their best due to being a part of an experimental study, regardless of the group allocation. Moreover this being a single blinded study the participants were unaware to which group they were allocated to, thereby avoiding any influence on their performance. Chinese study population: Although the study was conducted on Chinese population, the researchers constructed a strong study design with well-defined inclusion and exclusion criteria. This makes the study easily replicable on a different population. References: American Occupational Therapy Association. (2008). Physical agent modalities: A position paper. American Journal of Occupational Therapy, 62, 691 693. http://dx.doi.org/10.5014/ajot.62.6.691 De Kroon, J. R., Van der Lee, J. H., Ijzerman, M. J., Lankhorst, G.J. (2002). Therapeutic electrical stimulation to improve motor control and functional abilities of the upper extremity after stroke: a systematic review. Clinical Rehabilitation,16, 350 360. Heidenreich, P., Trogdon, J., Khavjou, O., Butler, J., Dracup, K., Ezekowitz, M., Woo, Y. (2011). Circulation, 123, 933 944. http://dx.doi.org/10.1161/cir.0b013e31820a55f5 This work is based on the evidence-based literature review completed by Divya R. Pandhi, B.O.Th, M.S.O.T, Revive Rehab Inc., Ponte Vedra Beach, FL and Pooja V. Joshi, B.O.Th, M.S.O.T., Aegis Therapies, Roosevelt Care Center, Edison, NJ, USA. CAP Worksheet adapted from Critical Review Form Quantitative Studies, copyright 1998, by M. Law, D. Stewart, N. Pollack, L. Letts, J. Bosch, & M. Westmorland, McMaster University. Used with permission. For personal or educational use only. All other uses require permission from AOTA. Contact: www.copyright.com 7