The approach that our group took was to find articles that dealt with the use of NMES for the rehabilitation of various impairments or deficits that occur after a person has had a stroke. Neuromuscular Electrical Stimulation (NMES) is the application of an electrical stimulus to a group of muscles, most often for the purpose of rehabilitation. The intent of NMES is to use electrical impulses to stimulate nerves in target muscles in order to try and “retrain” them to function properly again. Below we have provided articles that both support and refute the use NMES as an effective rehabilitation modality for stroke patients.
Articles Supporting NMES
In the study of Mesci, Ozdemir, and Kabayel et al., the researchers wanted to examine the effectiveness of Neuromuscular Electrical Stimulation (NMES) on chronic stroke patients who were receiving rehabilitation on their lower extremities. This study was a randomized single blind controlled trial that that involved 40 chronic stroke patients. The patients were randomly assigned to either the treatment (NMES) group or the control group. All patients received a conventional rehabilitation program for a 4-week period; in addition the treatment group received NMES treatment (for 4 weeks, 5 days a week) for hemiplegic foot dorsiflexor muscles (Mesci et al., 2009). Pre-treatment and post-treatment evaluations showed a significant increase in ankle dorsiflexion and a significant decrease in the level of spasticity in the treatment group when compared to the control group. Overall, this study found that the use of NMES in hemiplegic foot dorsiflexion can contribute to clinical improvements when used in combination with rehabilitation programs (Mesci et al., 2009).
The purpose of this assessor-blinded, block randomized, controlled investigation, by Shu-Shyuan, Ming-Hsia, Yen-Ho, Ping-Keung, Jan-Wei, and Ching-Lin, was to study how acute stroke patients respond to different doses of neuromuscular electrical stimulation (NMES) on the upper-extremity. Study participants were divided into three groups, the control group, the high dose NMES group with 60 minute sessions, and the low dose NMES group with 30 minute sessions. After the regular inpatient rehabilitation, which all subjects received, the NMES groups received 4 weeks of NMES treatment. Based on the subject's primary deficit, electrodes were placed over the extensor digitorum communis, extensor carpi radialis, flexor digitorum communis, supraspinatus, and/or the posterior deltoid. Outcomes were measured by the upper-extremity motor section of the Fugl-Meyer Motor Assessment Scale, Action Research Arm Test, and Motor activity Log. Results of the study showed a significant improvement for both the low dose and the high dose NMES when compared to the control group; however, there was not a significant difference between the two treatment groups.
The article “Long-Term Effectiveness Of Neuromuscular Electrical Stimulation For Promoting Motor Recovery Of The Upper Extremity After Stroke,” found NMES beneficial for upper extremity motor recovery in stroke patients. This study included 46 stroke survivors in a Chinese population who were split into a control group with standard rehab and an NMES intervention group also with standard rehab. The intervention group received NMES, with electrodes placed over the supraspinatus, deltoid, and wrist extensors, 30 minutes a day, five days per week, for three weeks. The NMES frequency was set at 30 Hz with a pulse width of 300 us and a 1 second ramp time. A symmetrical biphasic waveform was used as stimulus pulse. The amplitude was increased as high as the patient could tolerate, up to 90 mA, to produce full wrist extension and 30-50 degrees of shoulder abduction. The duty cycle used was 5 seconds on/off. Measurements including the Modified Ashworth Scale for spasticity, the Fugl-Meyer motor assessment (upper extremity section), and the Modified Barthel Index were taken at weeks two and three during intervention and at one, three, and six months post intervention. Results after three weeks of treatment and one month following the study found improvements in both groups. Results after three and six months post intervention found significantly higher average scores in the NMES group than the control group. The authors concluded that NMES following stroke is beneficial for upper extremity motor recovery for at least six months following treatment.
Articles Refuting the Use of NMES
The article “Randomized Controlled Trial to Evaluate the Effect of Surface Neuromuscular Electrical Stimulation to the Shoulder After Acute Stroke,” found the effectiveness of sNMES inconclusive regarding the functional outcome of the shoulder after acute stroke. This randomized control trial split 167 participants into two groups, a placebo group receiving only stroke unit care, and an intervention group receiving sNMES to the shoulder in addition to stroke unit care. The sNMES took place for one hour three times per day and the electrodes were placed over the supraspinatus and the posterior deltoid muscles. The frequency used was 30 Hz and the on/off time was 15 seconds with a 3 second ramp time. Intensity was increased until a muscle contraction was visible. The placebo group appeared to receive the same treatment as those who received sNMES but the stimulator was internally disconnected so that no treatment took place. The intervention lasted four weeks and was followed by primary measures of upper limb function using the Action Research Arm Test (ARAT) three months post stroke and secondary measures using the ARAT, Frenchay Arm Test, Motricity Index, Star Cancellation Test, pain scales, Nottingham E-ADL Index, Nottingham Health Profile, Oxford Handicap Scale, and participant views after the intervention and 3 months post stroke. The primary measure showed no difference between groups. Some secondary measures were improved in the placebo group 3 months post stroke, although there was no difference in ADL’s. The improvement in placebo over intervention was most prominent in those with initial severe impairment. The authors suggest this may be due to sNMES impeding the motor re-learning process and decreasing recovery in those with severe impairment. Immediately following intervention there was no difference between groups. The authors suggest use of sNMES for people with initial severe impairment may have negative affects due to the following reasons: abnormal proximal afferent stimulation inhibiting plasticity and interfering with distal recovery, overuse of the arm from movement produced by sNMES, insensitivity and lack of awareness of stimulation, production of tiredness and shoulder subluxation, and sNMES promoting decreased use of affected arm. The authors would like those with upper limb deficits post stroke to be aware of the possible negative consequences associated with sNMES.
In the review done by Meilink, Hemmen, and Seelen et al., they looked at whether Electromyography-triggered neuromuscular electrical stimulation (EMG-NMES) that was applied to the extensor muscles of the forearm could improve hand function after a stroke (Meilink, Hemmen, Seelen, & Kwakkel, 2008). The review was compiled via a computer-aided literature search and looked at comparing EMG-NMES of the upper extremity to usual rehabilitation protocol. Eight studies were chosen out of 192 hits, and these 8 studies provided the review with 157 patients. The meta-analysis of these reviews showed no significant effect sizes in favor of EMG-NMES for a number of tests including the Box and Block manipulation test, Action Reach ARM test and the Fugl-Meyer Motor Assessment Scale. The abilities that were tested in the various reviews were reaction time, manual dexterity, sustained contractibility and upper extremity synergy. The overall results of the review found that there was no statistical difference in the effects between EMG-NMES and the usual rehabilitation protocol. It was found that most studies has poor methodical quality, low statistical power and insufficient treatment contrast between experimental and control groups (Meilink et al., 2008).
The researchers, Yavuzer, Geler-Külcü, Sonel-Tur, Kutlay, Ergin, and Stam, performed a randomized controlled trial to observe the effect of neuromuscular electric stimulation (NMES) on ankle dorsiflexion during the first 6 months after a stroke, when added to a conventional stroke rehabilitation program. All participants received the conventional stroke rehabilitation program. In addition, the NMES group received 10 minutes of NMES to the affected anterior tibialis muscle. Outcome measures included lower-extremity motor recovery, assessed with the Brunnstrom stages for the lower extremity, and gait kinematics, assessing walking velocity, step length, percentage of stance phase at the paretic side, sagittal plane kinematics of the pelvis, hip, knee, and ankle, maximum ankle dorsiflexion angle at swing, and maximum ankle plantarflexion angle at initial contact. Both groups demonstrated an improvement between the beginning and the end of the study, however, there was not a significant difference between the groups, indicating that NMES was not an additive benefit to the conventional stroke rehabilitation program, when assessing motor recovery and gait kinematics with patients after a stroke.
References
Anon. Neuromuscular Electric Stimulation Effect on Lower-Extremity Motor Recovery and Gait Kinematics of Patients With Stroke: A Randomized Controlled Trial 10.1016/j.apmr.2005.12.041: Archives of Physical Medicine and Rehabilitation | ScienceDirect.com. Available at: http://www.sciencedirect.com.proxy.kumc.edu:2048/science/article/pii/S0003999306000487. Accessed February 24, 2012.
Church, C., Price, C., Pandyan, A. D., Huntley, S., Curless, R., & Rodgers, H. (2006). Randomized controlled trial to evaluate the effect of surface neuromuscular electrical stimulation to the shoulder after acute stroke. Stroke; a journal of cerebral circulation, 37(12), 2995-3001. doi:10.1161/01.STR.0000248969.78880.82
Gould, B. E., Dyer, R. M. (2011). Muskuloskeletal Disorders. Pathophysiology for the health professions. (4th ed., pp. 587-588). Saunders.
Hsu, S.-S., Hu, M.-H., Wang, Y.-H., Yip, P.-K., Chiu, J.-W., & Hsieh, C.-L. (2010). Dose-response relation between neuromuscular electrical stimulation and upper-extremity function in patients with stroke. Stroke; a journal of cerebral circulation, 41(4), 821-4. doi:10.1161/STROKEAHA.109.574160
Lin, Z., & Yan, T. (2011). Long-term effectiveness of neuromuscular electrical stimulation for promoting motor recovery of the upper extremity after stroke. Journal of rehabilitation medicine : official journal of the UEMS European Board of Physical and Rehabilitation Medicine, 43(6), 506-10. doi:10.2340/16501977-0807
Mesci, N., Ozdemir, F., Kabayel, D. D., & Tokuc, B. (2009). The effects of neuromuscular electrical stimulation on clinical improvement in hemiplegic lower extremity rehabilitation in chronic stroke: a single-blind, randomised, controlled trial. Disability and rehabilitation, 31(24), 2047-54. doi:10.3109/09638280902893626
I was able to find many recent studies that supported the use of NMES post-stroke for regaining functional muscle activity. These two studies I have chosen to summarize attempt to build on the traditional use of NMES with this patient population. One study looks at using electromyography with NMES and the other looks at contralaterally controlled functional electrical stimulation.
ReplyDelete1. Boyaci A, Topuz O, Alkan H, et al. Comparison of the effectiveness of active and passive neuromuscular electrical stimulation of hemiplegic upper extremities: a randomized, controlled trial. International journal of rehabilitation research. Internationale Zeitschrift fur Rehabilitationsforschung. Revue internationale de recherches de readaptation. 2013:1–8. doi:10.1097/MRR.0b013e328360e541.
This study compared the efficacy of electromyography (EMG) triggered neuromuscular electrical stimulation (NMES), passive NMES, and a placebo control group in a prospective randomized control trial of 31 subacute (< 6 months post) and chronic (> 6 months post) stage stroke patients with upper extremity motor and functional deficits. They concluded that both active and passive NMES plus neurophysiologic exercise was beneficial compared to the control, but was unable to find a significant difference between active and passive NMES and noted the need for further research specifically comparing the two treatments.
Each group received 45 minutes of the randomly assigned treatment 5 days a week for 3 weeks. For both active and passive NMES surface electrodes were placed over the extensor digitorum communis and extensor carpi ulnaris. The EMG triggered NMES (active NMES) protocol instructed patients to initiate wrist and finger extension until a preset level of EMG activity was met; then the NMES unit assisted the muscle to reach full range of motion. Patients were given visual and audio biofeedback. The EMG threshold was decreased to a level the patient was able to reach, and then increased each week after that threshold level was successfully met. The active NMES settings were 2s ramp up and down time, 10s of symmetric biphasic stimulation at 50Hz, 20-47 mA, pulse width of 200 μs, and current amplitude adjusted for patient comfort. The passive NMES settings were symmetric biphasic with a duty cycle of 10s on and 15s off, 2s ramp up and down time, 50 Hz, 20-47 mA, a pulse width 200 μs, and current amplitude adjusted to patient comfort. For the placebo treatment, surface electrodes were placed away from the motor point, and stimulation was set just above the sensory threshold but below motor activation. The active NMES, passive NMES, and placebo groups also performed an additional neurophysiologic exercise program for 45 minutes 5 days a week for 3 weeks.
Before and after treatment a physician, who was blinded to the study protocol and results, performed the UE component of the Fugl-Myer Motor Assessment (UE-FMA), the self-care component of the Functional Independence Measure (self-care FIM), the Motor Activity Log (MAL), goniometric measurements of active wrist and metacarpophalangeal joint extension, surface EMG potentials, grip strength, and the modified Ashworth scale. Between the active and passive NMES groups there was no significant difference in wrist and finger extensor spasticity. In comparison, the placebo group had a significant increase in wrist and finger extensor spasticity. The active and passive NMES groups had an increase in grip strength, with the active NMES group having a significant increase compared to the placebo group. Active NMES produced a greater but not significant increase in grip strength compared to the passive NMES group.
2. Knutson JS, Harley MY, Hisel TZ, Hogan SD, Maloney MM, Chae J. Contralaterally controlled functional electrical stimulation for upper extremity hemiplegia: an early-phase randomized clinical trial in subacute stroke patients. Neurorehabilitation and neural repair. 2012;26(3):239–46. doi:10.1177/1545968311419301.
ReplyDeleteThis study is a randomized clinical trial of contralaterally controlled functional electrical stimulation (CCFES) compared to cyclic NMES in stroke patients ≤ 6 months following their first hemorrhagic or nonhemorrhagic stroke. These patients had deficits in functional hand opening related to the extensors of the wrist and hand. They concluded that the CCFES group showed more improvements in all outcome measures, but that the power of their study (n=21) wasn’t sufficient to claim statistical significance of these results. The theory behind using this type of electrical stimulation is that the peripheral nerve activity of the involved limb reciprocal in timing and degree with the uninvolved limb correlates with central nervous system activity and promotion of Hebbian plasticity.
Both treatments lasted 6 weeks. Every participant would be guided through functional test practice once a week in the lab and then perform hand opening exercises daily on their own at home. Surface electrodes were placed on the extensor digitorum communis and extensor pollicis longis, the muscles needed for functional hand opening. The stimulators delivered biphasic rectangular current pulses at 35 Hz and 40 mA. The CCFES group wore a glove on the uninvolved hand that dictated the amount of stimulation was applied to the involved hand. The stimulator of the uninvolved hand was programmed to modulate the pulse duration in proportion to the amount of motion or opening in the gloved/uninvolved hand. Participants in both the CCFES group and cyclic NMES group were instructed on how to use their respective unit at home.
At the beginning and end of treatment, 1 month following treatment, and 3 months following treatment a blinded therapist assessed upper extremity impairment and activity limitation. They recorded maximum voluntary finger extension, finger movement control, upper limb portion of the Fugl-Meyer motor assessment, the Box and Blocks Test, and the Functional Ability component of the Arm Motor Abilities Test (AMAT). Due to the small sample size of this study (n = 21) testing for statistical significance of these findings would not be meaningful. However, the CCFES group had an average of 28° more of maximum voluntary finger extension across the post-treatment measures (calculated as a sum of the MCP and PIP angles). For every outcome measure the CCFES had greater improvements than the cyclic NMES group. A longer duration of study with a greater number of subjects is needed to build on these results.