FINAL POST!

In summary, NMES can be seen as a viable treatment tool in the rehabilitation of the upper limb post stroke. The main functional advantage offered by NMES is its ability to correctly position the humeral head in the glenoid fossa. This reduces sublaxation of the GHJ, which is a common complication of stroke. NMES fulfils this purpose by using a standard frequency of 50Hz, which is an optimal pulse frequency for muscle strengthening. This is in comparison to the wide frequency variations (1-200Hz) implemented by standard TENS machines. However, NMES treatment parameters are not specific to individual body parts.

Whilst the majority of literature is supportive of the use of NMES in rehabilitation programs post stroke, many studies also identify the fact that whilst NMES can help increase function and reduce sublaxation, it is not always effective in relieving upper limb pain. Furthermore, some evidence suggests that NMES may only be effective when the patient is receiving regular treatments.

A significant contraindication for use, which is specific to post stroke patients, is diminished or altered sensation.  Such sensory deficits can affect their ability to recognize the response of their body to the treatment. However, the cost effective nature of this treatment, coupled with the increasing demand placed on the health care system as a result of an ageing population, ensures it’s place as a crucial treatment modality for rehabilitation of the upper limb post stroke.

As this is our last post on this topic, we would like to thank all of you who have followed our progress and hopefully learnt from the information obtained. We look forward to learning more about the future direction and changes of NMES and its use in rehabilitation of the upper limb post stroke in the coming years.

This is Hayley and Meg, signing out.
:-)

   

Contraindications for the use of NMES post stroke.

In previous posts, we mentioned that we thought NMES was quite a viable method and potentially an important part in the rehabilitation of the upper limb post stroke. However, the more we thought about using NMES in this manner, the more we started thinking about safety with electrical equipment, such as NMES machines. Surely there must be some contraindications, precautions or safety procedures to follow when using these treatment methods?

Drussendorfer (2009) identifies a number of contraindications relating to the use of NMES in physiotherapy. These include:

• Stimulation through or across the chest, or over the carotid sinuses
•  Cardiac pacemakers or implanted stimulators
• Uncontrolled hypertension/hypotension
•  Peripheral vascular disease
• Pregnancy
• Acute inflammation
• Seizure history            
•  Confused patients or immature patients
• Obesity            
•  Osteoporosis

This was all well and good, however we decided to press on with our research in an attempt to find out whether there were any specific contraindications relating to the use of NMES on the upper limb post stroke,

The information we found was somewhat limited. However, the following conditions may be seen as factors which could, potentially, limit the use of NMES in post stroke clients. It should be noted, however, that this obviously depends on the magnitude of the stroke itself, the type of stroke suffered and the areas of the body affected as a result.

•         Diminished mental capacity: Porth & Matfin (2009), state that stroke can cause cognitive and behavioural deficits. Drussendorff (2009), identifies such deficits as possible contraindications in the use of NMES, especially when this diminished mental capacity decreases the ability of the individual to make informed decisions or understand the intended procedure.
• 
  
•          Sensory Deficits: Additionally, Porth & Matfin (2009) identify sensory deficits as extremely common amongst individuals post stroke. Drussendorfer (2009), identifies this decrease in sensation as a possible contraindication to the use of NMES. This is due to the fact that such individuals may be unable to recognize changes in the response of their body to the treatment, which can potentially lead to injuries such as skin burns.

Whilst we are now aware of the contraindications that may prevent individuals from using NMES in their rehabilitation programs post stroke, we also feel pretty happy with the fact that, in the majority of cases, it is both a safe and accessible treatment technique for such individuals. In our next and final post, we will endeavour to provide you with a summary of the most important findings of our topic.

Until then,
Hayley and Meg.
:-)

References

Drussendorfer, R. (2009). Stroke: Activities of Daily Living. Reviewed on the 30^th March (2011) at http://www.ebscohost.com/uploads/discovery/pdfs/topicFile-152.

Porth, C.M. & Matfin, G. (2009). Pathophysiology: Concepts of Altered Health States (8^th Ed.). Lippincott Williams & Wilkins: Philadelphia, PA.

NMES - exploring alternative viewpoints.

Well, what can we say? We did warn you in the previous post that this entry may not be too rosy, and it seems we have not failed to deliver. Over the past week we were saddened to find out that, unbelievably, not everyone is as supportive of the role of NMES in the rehabilitation of the upper limb post stroke as we detailed in our last post. We knew such universal praise was too good to be true!


Whilst the majority of the evidence we have discovered has been supportive of the role of NMES; Church, Price, Pandyan, Curless, Huntley & Rodgers (2006) not only failed to support the use of NMES, but went as far to say that they believed it can have negative consequences in relation to the recovery of the upper limb post stroke. They believe NMES may actually impede recovery by producing abnormal afferent stimulation proximally, which can later interfere with the recovery of distal tissues through maladaptive plasticity (Church et al, 2006). Once we managed to digest this rather intense lump of information, we realized that this was not good news. How many other professionals would dispute the use of NMES in such situations? We were determined to find out.

Figure 1.1. There is conflicting evidence for the role of NMES in increasing upper limb function post stroke.

In the days that followed we continued our search for information but were unable to find much other evidence that supported the statements presented by Church et al (2006). However, according to Maffiuletti (2010), there is often considerable variation between the conclusions drawn from various different studies. Basically, this infers that NMES current parameters are often poorly reported, and therefore may affect the outcome of such studies. In the same way, the methods used by researchers to evaluate NMES retraining effectiveness are usually quite heterogeneous, thereby rendering it difficult to compare the outcomes of the different NMES studies (Vanderthommen et al, 2007) to guage the overall effectiveness of this technique.


Confusion and sadness has now given way to clarity and a new optimism for the potential healing capacity of NMES. Comparison of our research over past posts identifies the fact that the majority of the literature supports the use of NMES in the recovery of the upper limb post stroke. Personally, we support this point of view, and believe in the abilities of NMES to aid recovery in such situations. What do you think?


Additionally, it was also indicated in our last blog that we would be discussing the future direction of NMES and its role in rehabilitation of the upper limb post stroke. Although difficult to find information relating to this specifically, we were able to determine that the future for this method is bright. With an ageing population who now enjoy increases in cardiovascular survival and many of whom also engage in other risk factors such as inactivity and smoking, it is predicted by many that the incidence of stroke will increase over the coming years (Niessen, Barendregt, Bonneux & Koudstaal, 1993). We believe that the use of NMES will therefore become more crucial and accepted as the demand for rehabilitation post-stroke increases, especially due to the cost-effective nature of NMES and the demand placed on the health care system from increased disease states in an ageing population (Yu, Chae, Walker, Kirsteins,, Elovic, Flanagan, Harvey, Zorowitz, Frost, Grill, Feldstein & Fang, 2004). Yu et al (2004) also believe in the future capabilities of NMES, especially due to recent technological advances which have increased the practicaliy and availability of clinical implementation. However they also state that, due to the somewhat poor quality of the research available, further studies are needed to expand upon proposed clinical applications and define more optimally advanced prescriptive parameters.


In our next and what will be our final post, we will endeavour to discuss relevant contraindications and safety procedures in regards to NMES and its use on individuals post-stroke.

Until then,
Hayley and Meg

References

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: Journal of the American Heart Association, 37, 2995-3001.


Maffiuletti., N.A. (2010). Physiological and methodological considerations for the use of neuromuscular electrical stimulation. European Journal Applied Physiology (110) 223–234.


Niessen, L. W., Barendregt, J. J., Bonneux, L. & Koudstaal, P. J. (1993). Stroke Trends in an Ageing Population. Stroke, 24, 931-939.


Vanderthommen. M. & Duchateau. J. (2007). Electrical stimulation as a modality to improve performance of the neuromuscular system. Exercise Sport Science Review (35)180–185.


Yu, D.T., Chae, J., Walker, M. E., Kirsteins, A., Elovic, E. P., Harvey, R. L., Zorowitz, R. D., Frost, F. S., Grill, J. H., Feldstein, M. & Fang, Z. (2004). Intramuscular Neuromuscular electrical stimulation for post stroke shoulder pain: A multicentre randomized clinical trial. Archives of Physical Medicine and Rehabilitation, 85 (5), 695-704. 


Images
http://linncitychiro.com/wp-content/uploads/2009/04/estim.jpg

NMES and Supportive Evidence

We’ve got NMES on our minds! Well, it’s hard not to now that we have gained such an extensive understanding of the appropriate NMES parameters needed to ensure optimal recovery of the upper limb post stroke. It now seems appropriate to review the literature further, the majority of which can be seen as supportive towards this particular electrotherapeutic device.

As we have been reviewing the relevant available literature in regards to NMES and its involvement with upper limb recovery post stroke, we have discovered that the majority of the studies we have analysed are supportive of the effective role NMES has on this condition. The literature supports the idea of electrical stimulation of the upper limb post stroke and its ability to reduce existing subluxation of the shoulder joint, decrease upper limb pain and facilitate recovery of upper limb function (Linn, Malcolm & Lees 1999). Thus, it has become apparent to us that NMES can be thought of as a ‘supportive backbone’ for stroke recovery.

Additionally, a randomized controlled study conducted by Linn et al (1999) was used to determine the efficacy of electrical stimulation in preventing shoulder subluxation in patients post stroke. Patients involved in the study were assessed within 48 hours of their stroke and those in the treatment group were immediately put on a regime of electrical stimulation for 4 weeks. All patients were assessed at 4 weeks and 12 weeks after stroke with assessments being made of shoulder subluxation, pain and motor control of the upper limb. Results indicated that the treatment group had significantly less subluxation and pain after the treatment period of four weeks, however at the end of the follow-up period (12 weeks) there were no significant difference between the 2 groups. Therefore, from analysing this study, it became apparent to us that NMES can prevent shoulder sublaxation and upper limb pain post stroke. However, the effects may be withdrawn when the patient stops receiving the treatment. We therefore began to wonder, is NMES only effective when the patient is receiving regular treatment?

Figure 5.1. Examples of the facilitation of muscle contractions in hemiparetic hands

Kimberly & Carey (2002) discuss the use of NMES in promoting recovery of the upper limb post stroke and make the brief statement that NMES can be seen as being beneficial in reducing shoulder subluxation but inconsistent in reducing shoulder pain. Basically what Kimberly & Carey (2002) are saying is that, whilst NMES has been found to have a positive effect on reducing sublaxation of the shoulder post stroke, it may not have this same positive result on reducing shoulder pain.

The study conducted by Vuagnat & Chantraine (2003) only had positive outcomes from NMES treatment. According to Vuagnat et al (2003) when NMES was applied early after the onset of the stroke in patients with shoulder pain and subluxation, only positive, beneficial effects on subluxation, pain and mobility of the upper limb were evident.

Furthermore, Yu, Chae, Walker, Kirsteins, Elovic, Flanagna, Harvey, Zorowitz, Frost, Grill, Felstein & Fang (2004) also support the effective use of NMES on upper limb post stroke recovery. In a single-blinded, randomized clinical trial where the subjects received NMES to the supraspinatus, posterior deltoid, middle deltoid and trapezius for 6 weeks, NMES reduced post stroke shoulder pain among those with shoulder subluxation. The effect was also maintained for at least 6 months post treatment, this highlighting the potential long term benefits NMES can have on the patients condition. This result differs from that previously discussed in the study by Linn et al (1999), as they suggest the benefits of NMES are only effective when the patient is receiving regular treatment.

Stroke Survivor's Hand Video Clip- this particular movie effectively illustrates NMES evoking electrical muscle contractions on the patient’s hemiparetic hand. This short clip is particularly confronting as the impairments which prevail post stroke are extremely apparent.

http://www.youtube.com/watch?v=VoAuB27RjDQ&feature=related

Hand Stimulation Video Clip- Although the following movie does not portray the same personal and emotional response as the first, it demonstrates electrical stimulation of just the forearm, hand and fingers. Examples of short pulses of electrical current which stimulate the muscles in the hand and fingers are demonstrated followed by sustained, long contractions which effectively stretch the hand and fingers. Both forms of electrical stimulation are effective in increasing function and muscular strength of the hand and fingers post stroke.

http://www.youtube.com/watch?v=kkT-SYFpw7M

We could continue analysing studies which support the literature on the effective and positive outcomes achieved through NMES in the recovery of upper limb function post stroke. However, we feel we have made our point crystal clear. The majority of relevant literature is supportive in the role of NMES treatment post stroke!

Our next blog may not be as rosy as we will look into the literature which believes NMES may actually impede recovery of upper limb recovery post stroke. We will also discuss the quality of literature and what the future holds for NMES.

However until then, keep smiling!

Hayley and Meg

REFERENCES;
Linn, S. L., Malcolm. H. & Lees, K.R. (1999) Prevention of Shoulder Subluxation After Stroke With Electrical Stimulation. American Heart Association, Inc. (30) 963-968.

Kimberly, T.T. & Carey, J.R. (2002) Neuromuscular electrical stimulation in stroke rehabilitation. University of Minnesota, USA.

Vuagnat. H. & Chantraine. A. (2003) Shoulder pain in hemiplegia revisited: contribution of functional electrical stimulation and other therapies. Journal of Rehabilitation Medicine 35(2):49-54.

Yu. D., T., Chae. J., Walker. M.E., Kirsteins. A., Elovic. E.P,, Flanagan. S.R., Harvey. R.L., Zorowitz. R.D., Frost. F.S., Grill. J.H., Feldstein. M. & Fang. Z.P. (2004) Intramuscular Neuromuscular Electric Stimulation for Post Stroke Shoulder Pain. Arch Phys Medicine Rehabilitation (85) 695-704.

Images;
http://www.mechanical-writings.com/post-stroke-rehabilitation/

NMES and Post Stroke Recovery

We were not planning on blogging today but would love for you all to see this particular movie. After having read so much literature in regards to NMES and the positive outcomes it can achieve in patients post stroke, we found it so refreshing to be able to finally visibly observe the life changing effect NMES has had on this particular stroke patient. Although this movie is not specific to upper limb recovery as it demonstrates restoring dorsiflexion of the foot, we could not help but share this exciting find! The movie is in Spanish, however, we feel visually it effectively portrays NMES improving function of the foot by electrically evoking muscle contractions, thus increasing muscular strength of the hemiparetic limb. ENJOY!

http://espanol.video.yahoo.com/watch/7497559/19860432 

Next blog will be reviewing the literature which demonstrates supportive evidence towards the NMES treatment of the upper limb recovery post stroke.

Meg and Hayley.

NMES Parameters

After another productive afternoon of reviewing the literature, we now feel we have successfully wrapped our heads around the appropriate NMES parameters for treatment in regards to rehabilitation of the upper limb post stroke. We found these parameters to be remarkably similar to those regarding the other limbs of the body post stroke, thus coming to the conclusion that NMES parameters do not change a great deal from limb to limb. Infact, the following parameters are enough to suffice the recovery of many different body segments post stroke. All the reviewed literature had varying stimulation parameters, thus leaving us to believe NMES stimulation parameters are not specifically crucial in determining the motor outcomes, as all of the studies we read through resulted in some degree of positive outcomes.

Table 3.1: An Example of Parameter Guidelines for NMES Upper Limb Function Post Stroke; (NMES Guidelines for Treatment, 2010)

Electrode Placement	Important to confine the electrode placement to the treatment area thus minimising the overflow to other muscles. Therefore selection of the largest possible electrode within these guidelines is optimal. Negative electrode placed over posterior deltoid. Positive electrode placed above spine of the scapula, over supraspinatus muscle (avoiding placement over the upper trapezius muscle)
Pulse Frequency	25-50Hz
Pulse Duration	200-300 microseconds
Ramp	Optimally 1-3 seconds (however use patient comfort as the guide)
On:Off Cycle	Initially 1:3 ratio implemented. Important muscular fatigue is avoided. Fatigue can be measured by palpating the amount of sublaxation evident at the end of the session of each treatment. GOAL; increase ‘on’ time by 2 seconds daily or every treatment session until achievement of 24-30 seconds. Once this ‘on’ time benchmark is achieved, aim is to decrease ‘off’ time in 2 second intervals. Optimal goal is to achieve a 12:1/ 15:1 ratio.
Waveform	Asmmetrical Biphasic. A symmetrical biphasic waveform has been shown  to reduce the amount of amplitude needed to achieve a stimulated muscle contraction. This reduced current intensity decreases the amount of superficial sensory activation, often making the patient more comfortable and, thus, more willing to comply with the treatment program.
Intensity	A tetanised-muscle contraction- 12.5Hz. Fatigue should be monitored during treatment sessions to ensure reduction is maintained.
Treatment Duration	NMES application in clinical setting à progressing to a home program as quickly as possible. Initially 3x 30 minute daily sessions. The program ideally continues until the individual regains independant functional control of the upper limb musculature.

After looking at the parameters for NMES responsible for optimal functional recovery, we began to wonder how they differ from other electrotherapy modalities. Balanger (2010) explains the varying optimal frequencies are the most significant difference between NMES and other electrical stimulation modalities. TENS for example, uses frequencies between 1-200Hz in comparison to the pulse frequency of 50Hz employed most commonly by NMES. The pulse frequency of 50Hz utilized by NMES is ideal for muscle strengthening due to the resulting fused titanic contraction within the muscle fibres, which in turn increases fibre strength (Balanger, 2010).


According to Chae, et al (2008) NMES is the electrical stimulation device of choice in relation to upper limb stroke as NMES provides therapeutic and functional benefits that lead to enhanced functions, however it doesn’t directly provide function. Chae, et al (2008) explains the importance of the prerequisites the patient must possess in order to achieve the most effective results. These include; mediated motor learning, concurrent volitional effort and high functional content. 

Figure 3.1; NMES stimulation of the wrist used for optimal functional recovery of the wrist

Excited by another discovery, we have included additional NMES Guidelines which include NMES parameters associated with finger flexion, extension, thumb opposition and grip re-education of the lumbrical muscles.

NMES Hand Rehabilitation Guidelines;

http://www.empi.com/uploadedFiles/Empi_Products/Pain_Management_-_TENS/hand.pdf

Figure 3.2; NMES has a significant impact on restoring optimal functional ability of a stroke patients hand

  Figure 3.3; An example of the use of NMES optimally mimicking functional tasks, for example the grasping action in a CVA patient

The next time we cross paths will be looking further into the research and studies which demonstrate supportive evidence towards the NMES treatment of the upper limb recovery post stroke - another area which promises exciting findings!

Until then,

Hayley and Meg

REFERENCES;

Belanger, A.Y. (2010) Therapeutic Electrophysical Agents. Evidence Based Practice. 2^nd Edition. Philadelphia. Lippincott Williams & Wilkins.

Chae, J., Bethoux, F., Bohinc, T., Dobos, L., Davis, T. & Friedl, A. (1998) Neuromuscular Stimulation for Upper Extremity Motor and Functional Recovery in Acute Hemiplegia. Stroke. (29) 975-979.

NMES Guidelines for Treatment. (2010) Retrieved February 25, 2011.

http://www.empi.com/uploadedFiles/Empi_Products/Pain_Management_-_TENS/gait

IMAGES;

http://www.drakecenter.com/page/Neuromuscular-re-education-and-strengthening.aspx

http://www.couragecenter.org/ContentPages/stilwellmed4.aspx

http://www.electrostim.ro/index_e.php?p=MICROSTIM2v2_stimulator

http://www.sciencephoto.com/images/download_lo_res.html?id=777200448

http://www.flickr.com/photos/existentialexits/323164114/

An Exciting Find on NMES and Shoulder Sublaxation

Whilst sitting back on a Friday afternoon and reflecting upon our last blog post (now with a significantly greater understanding of hemiplegia and how it has the potential to affect a stroke victims everyday life so drastically), we began reviewing the literature surrounding NMES parameters and clinical studies. Chae et al (1998), explains that the nerve fibre recruitment properties elicited by normal physiological mechanisms and NMES have contrasting preferences. Normal physiological mechanisms initially recruit the neurons with the smallest diameter prior to the recruitment of larger diameter fibres. This differs from Neuromuscular Electrical Stimulation (NMES) which mediates a nerve recruitment pattern following the principle of ‘reverse recruitment order’, thus preferentially recruiting the large-diameter nerve fibres which are responsible for innervating the larger motor units (Sheffler et al, 2007).

As we continued to read articles in relation to NMES and upper limb recovery post stroke, we came across an interesting article and substantial supportive evidence in regards to NMES and its ability to reduce sublaxation of the shoulder joint. This is achieved through NMES inducing contractions of the shoulder muscles, thus pulling the head of the humerus into the glenoid fossa (Chae et al, 1998). Re-education of the glenohumeral joint is an essential requirement of a post stroke rehabilitation program as it ensures the anatomically correct positioning of the humeral head in the glenoid fossa. As a result of NMES ensuring this correct joint alignment, a stable base is maintained for optimal functional use of the upper extremity (NMES Guidelines for Treatment, 2010). Whilst reflecting upon this article we began to appreciate NMES’ ability to ensure that the correct alignment of the shoulder joint is achieved post stroke.

Figure 2.1. Shoulder subluxation and the use of electrical stimulation. The top image displays chronic shoulder sublaxation. The bottom image shows the alignment of the shoulder during application of electrical stimulation.

Excited by our new found understanding of the role NMES plays in post stroke recovery of the upper limb, we continued to review the literature. Baker & Parker (1986) ensured our knowledge of the topic continued to develop. They stated that the primary advantage of NMES is its ability to maintain joint integrity throughout the flaccid period of post stroke recovery, thus preventing the early implementation of stretching the shoulder capsule (Baker et al, 1986). Due to the complexities of this multi-articular joint, NMES is most useful in the initial phase of ROM. As we continued to reflect upon what we were reading, our understanding grew. We were now fully aware that because of the multi-articular nature of the shoulder joint, NMES provides the initial foundation and enhances the development of muscle strength and function of the upper limb post stroke. AMAZING!

       

Figure 2.2. Comparison of a stable shoulder capsule and a shoulder capsule post sublaxation

According to Chae et al (1998), early protection of the shoulder capsule has the capability to result in a faster recovery of the upper extremity function post stroke. Just as we began to think nothing could hamper the positive outcomes of NMES and its' ability to facilitate recovery post stroke, Sheffler et al (2007) proved us wrong. Sheffler et al (2007) explains that the clinical application of NMES is currently limited to neurological injuries involving the Upper Motor Neuron (UMN), including conditions such as spinal cord injury, stroke and cerebral palsy, being dependant on intact alpha Lower Motor Neurons (LMN). We can therefore conclude that NMES treatment and UMN conditions are inextricably linked.

Figure 2.3. NMES and its limitation to neurological injuries involving the Upper Motor Neuron

With our understanding of NMES and the positive impact it has on reducing sublaxation of the shoulder capsule post stroke now completely fuelled, we look forward to going into greater detail of the NMES parameters specific to post stroke upper limb recovery next time!

Until then,
Meg and Hayley.

REFERENCES

Baker. L.L. & Parker. K. (1986) Neuromuscular Electrical Stimulation of the Muscles Surrounding the Shoulder. Annual Biomedical Eng 66 (12).

Chae, J., Bethoux, F., Bohinc, T., Dobos, L., Davis, T. & Friedl, A. (1998) Neuromuscular Stimulation for Upper Extremity Motor and Functional Recovery in Acute Hemiplegia. Stroke. (29) 975-979.

Sheffer, L.,R. & Chae, J. (2007) Neuromuscular electrical stimulation in neurorehabilitation 35(5); 562- 590.

NMES Guidelines for Treatment. (2010) Retrieved February 25, 2011.
http://www.empi.com/uploadedFiles/Empi_Products/Pain_Management_-_TENS/gait

Images;
http://stroke.ahajournals.org/cgi/content/full/30/5/963/F1
http://www.ottobock.com/cps/rde/xchg/ob_us_en/hs.xsl/15708.html
http://mywellcare.ca/physiotherapy/tens_units
http://injuryexplained.com/frozenshoulder.html
http://www.inmotionjax.com/exercise/Instability.html