Posts Tagged Electrical Stimulation

[WEB SITE] Transcutaneous electrical stimulation (TENS) may help lower limb spasticity after stroke

Adult using TENS machine for lower limb pain

Published on 26 February 2019

doi: 10.3310/signal-000738

Transcutaneous electrical stimulation (TENS) delivered alongside standard physical therapies could reduce spasticity in the lower limbs following a stroke.

Spasticity is a muscle control disorder characterised by tight muscles. It is common after stroke and accounts for significant disability. TENS is often used to treat pain and can affect nervous stimulation of the muscles.

The main evidence in this systematic review came from five trials which suggested that TENS combined with other physical therapies has moderate effect on lower limb spasticity compared with placebo.

The review has limitations, with small studies and little evidence on use for upper limbs or comparing with other therapies. However, TENS machines are portable, inexpensive and widely accessible making them an appealing addition to other care.

NICE does not currently recommend the use of TENS in stroke rehabilitation, though guidance covers use of other types of electrical stimulation in certain other contexts.

Why was this study needed?

More than 1.2 million people in the UK are living with the effects of stroke. About two-thirds of stroke survivors leave hospital with residual disability and one quarter experience spasticity.

Electrical stimulation is sometimes used as treatment after a stroke. It includes functional electrical stimulation and neuromuscular electrical stimulation, which both focus on muscle contraction. Transcutaneous electrical stimulation (TENS) targets the sensory nerves in a different way.

Transcutaneous electrical stimulation has been suggested as an adjunct to other rehabilitation therapy to try and reduce spasticity. The device is portable and can be self-administered at home, so its potential for managing spasticity is appealing.

There have been a number of small studies of TENS with conflicting results. This review aimed to combine the results to see if there was evidence for its use to treat spasticity after stroke.

What did this study do?

This systematic review identified 15 studies (10 randomised controlled trials) reporting the effectiveness of TENS on spasticity after stroke.

Studies compared TENS, used alone or alongside other therapies such as functional exercises, with placebo, no treatment or other treatments. Thirteen studies assessed lower limb spasticity, with 11 targeting the ability to flex the foot. Most assessed use in the chronic rather than acute phase of stroke.

Transcutaneous electrical stimulation regimen varied widely. Intervention periods ranged from one day to 12 weeks, the number of TENS sessions from one to seven per week, and the duration of sessions ranged from less than 20 minutes up to 60 minutes.

Trials were small with maximum participant size 80. The quality of randomised controlled trials was good overall, with lack of participant blinding being the most likely source of bias. Seven trials were pooled in meta-analysis.

What did it find?

  • Transcutaneous electrical stimulation used alongside other physical therapies was moderately effective in reducing spasticity in the lower limbs compared with placebo (standard mean difference [SMD] -0.64, 95% confidence interval [CI] -0.98 to -0.31). This was from meta-analysis of five trials (221 adults) with broadly similar results.
  • Pooled results of two trials (60 adults) also found that TENS alongside other physical therapies was more effective at reducing spasticity than no TENS (SMD -0.83, 95% CI -1.51 to -0.15).
  • Five studies assessed longer-term effects on spasticity. Three studies found the effects were maintained for a period of two to five weeks whilst two studies found the effects lasted for less than a day and that spasticity returned to baseline levels immediately following the intervention.
  • None of the studies reported any adverse effects of TENS.

What does current guidance say on this issue?

The NICE guideline on stroke rehabilitation (2013) does not currently include recommendations for use of TENS. NICE advises against the routine use of electrical stimulation for the hand and arm but suggests a trial of treatment may be considered if there is sign of muscle contraction, and the person cannot move their arm against resistance.

NICE guidance from 2009 advises that there is sufficient evidence that functional electrical stimulation can improve walking in people with drop foot following a stroke, provided the normal arrangements are in place for clinical governance, consent and audit.

What are the implications?

This review suggests that TENS, when delivered alongside other physical therapies, could be considered for lower limb spasticity as part of a stroke rehabilitation programme.

The findings are similar to a 2015 systematic review which found that electrical stimulation gave small but significant improvements in spasticity following stroke. Again this earlier review was limited by small sample sizes, varied treatment regimens and few studies that could be pooled in meta-analysis.

There was insufficient evidence to support use for upper limbs.

Cost was not assessed, but TENS is a non-invasive therapy and devices are widely available and could easily be used at home.

Citation and Funding

Mahmood A, Veluswamy SK, Hombali A, et al. Effect of transcutaneous electrical nerve stimulation on spasticity in adults with stroke: a systematic review and meta-analysis. Arch Phys Med Rehabil. 2018; 16 November. doi: 10.1016/j.apmr.2018.10.016. [Epub ahead of print].

No funding information was provided for this study.

Bibliography

NICE. Functional electrical stimulation for drop foot of central neurological origin. IPG278. London: National Institute for Health and Care Excellence; 2009.

NICE. Stroke rehabilitation in adults. CG162. London: National Institute for Health and Care Excellence; 2013.

NICE. Spasticity (after stroke) – botulinum toxin type A. ID768. London: National Institute for Health and Care Excellence; in development.

Stein C, Fritsch CG, Robinson C et al. Effects of electrical stimulation in spastic muscles after stroke: systematic review and meta-analysis of randomized controlled trials. Stroke. 2015;46(8):2197-205.

Stroke Association. State of the nation: stroke statistics. London: Stroke Association; 2018.

 

  1. Analysis of the Faster Knee-Jerk In the Hemiplegic Limb
    TAKAO NAKANISHI et al., JAMA Neurology, 1965
  2. Transcutaneous Electrical Stimulation
    WILLIAM BAUER et al., JAMA Otolaryngology Head Neck Surgery, 1986

via Transcutaneous electrical stimulation (TENS) may help lower limb spasticity after stroke

, , , , , , , , ,

Leave a comment

[Abstract + References] Effect of Transcutaneous Electrical Nerve Stimulation on Spasticity in Adults With Stroke: A Systematic Review and Meta-analysis

Abstract

Objectives

(1) To determine the effect of transcutaneous electrical nerve stimulation (TENS) on poststroke spasticity. (2) To determine the effect of different parameters (intensity, frequency, duration) of TENS on spasticity reduction in adults with stroke. (3) To determine the influence of time since stroke on the effectiveness of TENS on spasticity.

Data Sources

PubMed, PEDro, CINAHL, Web of Science, CENTRAL, and EMBASE databases were searched from inception to March 2017.

Study Selection

Randomized controlled trial (RCT), quasi-RCT, and non-RCT were included if (1) they evaluated the effects of TENS for the management of spasticity in participants with acute or subacute or chronic stroke using clinical and neurophysiological tools; and (2) TENS was delivered either alone or as an adjunct to other treatments.

Data Extraction

Two authors independently screened and extracted data from 15 of the 829 studies retrieved through the search using a pilot tested pro forma. Disagreements were resolved through discussion with other authors. Quality of studies was assessed using Cochrane risk of bias criteria.

Data Synthesis

Meta-analysis was performed using a random-effects model that showed (1) TENS along with other physical therapy treatments was more effective in reducing spasticity in the lower limbs compared to placebo TENS (SMD −0.64; 95% confidence interval [95% CI], −0.98 to −0.31; P=.0001; I2=17%); and (2) TENS, when administered along with other physical therapy treatments, was effective in reducing spasticity when compared to other physical therapy interventions alone (SMD −0.83; 95% CI, −1.51 to −0.15; P=.02; I2=27%). There were limited studies to evaluate the effectiveness of TENS for upper limb spasticity.

Conclusion

There is strong evidence that TENS as an adjunct is effective in reducing lower limb spasticity when applied for more than 30 minutes over nerve or muscle belly in chronic stroke survivors (review protocol registered at PROSPERO: CRD42015020151)

References

  1. Zorowitz, R.D., Gillard, P.J., Brainin, M. Poststroke spasticity. Neurology. 2013;80:S45–S52
  2. Wissel, J., Manack, A., Brainin, M. Toward an epidemiology of poststroke spasticity. Neurology. 2013;80:S13–S19
  3. Watkins, C.L., Leathley, M.J., Gregson, J.M., Smith, T.L., Moore, A.P. Prevalence of spasticity post stroke. Clin Rehabil. 2002;16:515–522
  4. Doan, Q.V., Brashear, A., Gillard, P.J. et al, Relationship between disability and health-related quality of life and caregiver burden in patients with upper limb poststroke spasticity. PM R. 2012;4:4–10
  5. Lundström, E., Smits, A., Borg, J., Terént, A. Four-fold increase in direct costs of stroke survivors with without spasticity the first year after the event. Stroke. 2010;41:319–324
  6. Winstein, C.J., Stein, J., Arena, R. et al, Guidelines for adult stroke rehabilitation and recovery: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2016;47:e98–e169
  7. Thibaut, A., Laureys, S., Gosseries, O., Chatelle, C., Ziegler, E. Spasticity after stroke: physiology, assessment and treatment. Brain Inj. 2013;9052:1–13
  8. Richardson, D. Physical therapy in spasticity. Eur J Neurol. 2002;9:17–22
  9. Malas, B., Kacen, M. Orthotic management in patients with stroke. Top Stroke Rehabil. 2001;7:38–45
  10. Lehmann, J.F., Esselman, P.C., Ko, M.J., Smith, J.C., deLateur, B.J., Dralle, A.J. Plastic ankle-foot orthoses: evaluation of function. Arch Phys Med Rehabil. 1983;64:402–407
  11. Barnes, M.P. Medical management of spasticity in stroke. Age Ageing. 2001;30:13–16
  12. Kocabas, H. Comparison of phenol and alcohol neurolysis of tibial nerve motor branches to the gastrocnemius muscle for treatment of spastic foot after stroke: a randomized controlled pilot study.Eur J Phys Rehabil Med. 2010;46:5–10
  13. Fukuhara, T., Kamata, I. Selective posterior rhizotomy for painful spasticity in the lower limbs of hemiplegic patients after stroke: report of two cases. Neurosurgery. 2004;54:1268–1273
  14. Sheean, G., McGuire, J.R. Spastic hypertonia and movement disorders: pathophysiology, clinical presentation, and quantification. PM R. 2009;1:827–833
  15. Martins, F.L., Carvalho, L.C., Silva, C.C., Brasileiro, J.S., Souza, T.O., Lindquist, A.R. Immediate effects of TENS and cryotherapy in the reflex excitability and voluntary activity in hemiparetic subjects: a randomized crossover trial. Rev Bras Fisioter. 2012;16:337–344
  16. Kim, T.H., In, T.S., Cho, H. Task-related training combined with transcutaneous electrical nerve stimulation promotes upper limb functions in patients with chronic stroke. Tohoku J Exp Med. 2013;231:93–100
  17. Tinazzi, M., Zarattini, S., Valeriani, M. et al, Long-lasting modulation of human motor cortex following prolonged transcutaneous electrical nerve stimulation (TENS) of forearm muscles: evidence of reciprocal inhibition and facilitation. Exp Brain Res. 2005;161:457–464
  18. Yan, T., Hui-Chan, C.W. Transcutaneous electrical stimulation on acupuncture points improves muscle function in subjects after acute stroke: a randomized controlled trial. J Rehabil Med. 2009;41:312–316
  19. Tekeoğlu, Y., Adak, B., Göksoy, T. Effect of transcutaneous electrical nerve stimulation (TENS) on Barthel activities of daily living (ADL) index score following stroke. Clin Rehabil. 1998;12:277–280
  20. Sonde, L., Kalimo, H., Viitanen, M. Stimulation with high-frequency TENS — effects on lower limb spasticity after stroke. Adv Physiother. 2000;2:183–187
  21. Jung, K.-S., In, T.-S., Cho, H. Effects of sit-to-stand training combined with transcutaneous electrical stimulation on spasticity, muscle strength and balance ability in patients with stroke: a randomized controlled study. Gait Posture. 2017;54:183–187
  22. Picelli, A., Dambruoso, F., Bronzato, M. et al, Efficacy of therapeutic ultrasound and transcutaneous electrical nerve stimulation compared with botulinum toxin type A in the treatment of spastic equinus in adults with chronic stroke: a pilot randomized controlled trial. Top Stroke Rehabil. 2014;21:S8–S16
  23. Sonde, L., Gip, C., Fernaeus, S.E., Nilsson, C.G., Viitanen, M. Stimulation with low frequency (1.7 Hz) transcutaneous electric nerve stimulation (low-tens) increases motor function of the post-stroke paretic arm. Scand J Rehabil Med. 1998;30:95–99
  24. Branco Mills, P., Dossa, F. Transcutaneous electrical nerve stimulation for management of limb spasticity. Am J Phys Med Rehabil. 2016;95:309–318
  25. Lin, S., Sun, Q., Wang, H., Xie, G. Influence of transcutaneous electrical nerve stimulation on spasticity, balance, and walking speed in stroke patients: a systematic review and meta-analysis. J Rehabil Med. 2018;50:3–7
  26. Ng, S.S., Hui-Chan, C.W. Transcutaneous electrical nerve stimulation combined with task-related training improves lower limb functions in subjects with chronic stroke. Stroke. 2007;38:2953–2959
  27. Cho, H., In, T.S., Cho, K.H., Song, C.H. A single trial of transcutaneous electrical nerve stimulation (TENS) improves spasticity and balance in patients with chronic stroke. Tohoku J Exp Med. 2013;229:187–193
  28. Potisk, K.P., Gregoric, M., Vodovnik, L. Effect of transcutaneous electrical nerve stimulation (TENS) on spasticity in patients with hemiplegia. Scand J Rehabil Med. 1995;27:169–174
  29. Levin, M.F., Hui-Chan, C.W. Relief of hemiparetic spasticity by TENS is associated with improvement in reflex and voluntary motor functions. Electroencephalogr Clin Neurophysiol. 1992;85:131–142
  30. Bernhardt, J., Hayward, K.S., Kwakkel, G. et al, Agreed definitions and a shared vision for new standards in stroke recovery research: the Stroke Recovery and Rehabilitation Roundtable taskforce. Int J Stroke. 2017;12:444–450
  31. Cochrane Effective Practice and Organisation of Care. Suggested risk of bias criteria for EPOC reviews. (Available at:)http://epoc.cochrane.org/resources/epoc-resources-review-authors(Accessed August 22, 2018)
  32. Higgins, J.P., Green, S. Cochrane handbook for systematic reviews of interventions: version 5.1.0.(Available at:)http://handbook.cochrane.org(Accessed August 27, 2018)
  33. Hussain, T., Mohammad, H. The effect of transcutaneous electrical nerve stimulation (TENS) combined with Bobath on post stroke spasticity. A randomized controlled study. J Neurol Sci. 2013;4:22–29
  34. Park, J., Seo, D., Choi, W., Lee, S. The effects of exercise with tens on spasticity, balance, and gait in patients with chronic stroke: a randomized controlled trial. Med Sci Monit. 2014;20:1890–1896
  35. Laddha, D., Ganesh, G.S., Pattnaik, M., Mohanty, P., Mishra, C. Effect of transcutaneous electrical nerve stimulation on plantar flexor muscle spasticity and walking speed in stroke patients. Physiother Res Int. 2016;21:247–256
  36. Hui-Chan, C.W., Levin, M.F. Stretch reflex latencies in spastic hemiparetic subjects are prolonged after transcutaneous electrical nerve stimulation. Can J Neurol Sci. 1993;20:97–106
  37. Karakoyun, A., Boyraz, İ., Gunduz, R., Karamercan, A., Ozgirgin, N. Electrophysiological and clinical evaluation of the effects of transcutaneous electrical nerve stimulation on the spasticity in the hemiplegic stroke patients. J Phys Ther Sci. 2015;27:3407–3411
  38. Koyama, S., Tanabe, S., Takeda, K., Sakurai, H., Kanada, Y. Modulation of spinal inhibitory reflexes depends on the frequency of transcutaneous electrical nerve stimulation in spastic stroke survivors.Somatosens Mot Res. 2016;33:8–15
  39. Okuma, Y., Lee, R.G. Reciprocal inhibition in hemiplegia: correlation with clinical features and recovery. Can J Neurol Sci. 1996;23:15–23
  40. Sommerfeld, D.K., Gripenstedt, U., Welmer, A.-K. Spasticity after stroke. Am J Phys Med Rehabil. 2012;91:814–820
  41. Fernández-Tenorio, E., Serrano-Muñoz, D., Avendaño-Coy, J., Gómez-Soriano, J. Transcutaneous electrical nerve stimulation for spasticity: a systematic review. Neurologia. 2016; (pii: S0213-4853(16)30111-6)
  42. Kwong, P.W., Ng, G.Y., Chung, R.C., Ng, S.S. Transcutaneous electrical nerve stimulation improves walking capacity and reduces spasticity in stroke survivors: a systematic review and meta-analysis.Clin Rehabil. 2018;32:1203–1219

source:
https://www.archives-pmr.org/article/S0003-9993(18)31455-2/abstract

, , , , , ,

Leave a comment

[Abstract] Effect of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors: a randomized controlled trial

PDF

 

BACKGROUND: When solely mirror therapy is applied for a long period of time, spatial perception and attention to the damaged side may decrease, and the effect of mirror therapy may be limited. To overcome this limitation, it has recently been suggested that the combination of mirror therapy with mirror treatment is effective.
AIM: The aim of this study was to investigate the effects of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors.
DESIGN: A randomized controlled trial.
SETTING: Rehabilitation center.
POPULATION: Thirty stroke survivors were randomly assigned to two groups: the experimental group (n = 15) and the control group (n = 15).
METHODS: Participants of the experimental group received afferent electrical stimulation with mirror therapy, and participants of the control group received sham afferent electrical stimulation with sham mirror therapy for 60 minutes per day, 5 days per week, for 4 weeks. Motor function was measured using a handheld dynamometer and the Modified Ashworth Scale, balance was measured using the Berg Balance Scale, and gait was assessed using the GAITRite at baseline and after 4 weeks.
RESULTS: The experimental group showed significant differences in muscle strength, Modified Ashworth Scale, and Berg Balance Scale results, and velocity, cadence, step length, stride length, and double support time of their gait (p <0.05) in the pre-post intervention comparison. Significant differences between the two groups in muscle strength, Berg Balance Scale, gait velocity, step length, and stride length (p <0.05) were found.
CONCLUSIONS: Mirror therapy with afferent electrical stimulation may effectively improve muscle strength and gait and balance abilities in hemiplegic stroke survivors.
CLINICAL REHABILITATION IMPACT: Afferent electrical stimulation combined with mirror therapy can be used as an effective intervention to improve lower limb motor function, balance, and gait in chronic stroke survivors in clinical settings.

via Effect of afferent electrical stimulation with mirror therapy on motor function, balance, and gait in chronic stroke survivors: a randomized controlled trial – European Journal of Physical and Rehabilitation Medicine 2019 Mar 22 – Minerva Medica – Journals

, , , , ,

Leave a comment

[WEB SITE] Electrical stimulation in brain bypasses senses, instructs movement

Date:December 7, 2017
Source:University of Rochester Medical Center
Summary:The brain’s complex network of neurons enables us to interpret and effortlessly navigate and interact with the world around us. But when these links are damaged due to injury or stroke, critical tasks like perception and movement can be disrupted. New research is helping scientists figure out how to harness the brain’s plasticity to rewire these lost connections, an advance that could accelerate the development of neuro-prosthetics.
FULL STORY

The brain’s complex network of neurons enables us to interpret and effortlessly navigate and interact with the world around us. But when these links are damaged due to injury or stroke, critical tasks like perception and movement can be disrupted. New research is helping scientists figure out how to harness the brain’s plasticity to rewire these lost connections, an advance that could accelerate the development of neuro-prosthetics.

A new study authored by Marc Schieber, M.D., Ph.D., and Kevin Mazurek, Ph.D. with the University of Rochester Medical Center Department of Neurology and the Del Monte Institute for Neuroscience, which appears in the journal Neuron, shows that very low levels of electrical stimulation delivered directly to an area of the brain responsible for motor function can instruct an appropriate response or action, essentially replacing the signals we would normally receive from the parts of the brain that process what we hear, see, and feel.

“The analogy is what happens when we approach a red light,” said Schieber. “The light itself does not cause us to step on the brake, rather our brain has been trained to process this visual cue and send signals to another parts of the brain that control movement. In this study, what we describe is akin to replacing the red light with an electrical stimulation which the brain has learned to associate with the need to take an action that stops the car.”

The findings could have significant implications for the development of brain-computer interfaces and neuro-prosthetics, which would allow a person to control a prosthetic device by tapping into the electrical activity of their brain.

To be effective, these technologies must not only receive output from the brain but also deliver input. For example, can a mechanical arm tell the user that the object they are holding is hot or cold? However, delivering this information to the part of the brain responsible for processing sensory inputs does not work if this part of the brain is injured or the connections between it and the motor cortex are lost. In these instances, some form of input needs to be generated that replaces the signals that combine sensory perception with motor control and the brain needs to “learn” what these new signals mean.

“Researchers have been interested primarily in stimulating the primary sensory cortices to input information into the brain,” said Schieber. “What we have shown in this study is that you don’t have to be in a sensory-receiving area in order for the subject to have an experience they can identify.”

A similar approach is employed with cochlear implants for hearing loss which translate sounds into electrical stimulation of the inner ear and, over time, the brain learns to interpret these inputs as sound.

In the new study, the researchers detail a set of experiments in which monkeys were trained to perform a task when presented with a visual cue, either turning, pushing, or pulling specific objects when prompted by different lights. While this occurred, the animals simultaneously received a very mild electrical stimulus called a micro-stimulation in different areas of the premotor cortex — the part of the brain that initiates movement — depending upon the task and light combination.

The researchers then replicated the experiments, but this time omitted the visual cue of the lights and instead only delivered the micro-stimulation. The animals were able to successfully identify and perform the tasks they had learned to associate with the different electrical inputs. When the pairing of micro-stimulation with a particular action was reshuffled, the animals were able to adjust, indicating that the association between stimulation and a specific movement was learned and not fixed.

“Most work on the development of inputs to the brain for use with brain-computer interfaces has focused primarily on the sensory areas of the brain,” said Mazurek. “In this study, we show you can expand the neural real estate that can be targeted for therapies. This could be very important for people who have lost function in areas of their brain due to stroke, injury, or other diseases. We can potentially bypass the damaged part of the brain where connections have been lost and deliver information to an intact part of the brain.”

Story Source:

Materials provided by University of Rochester Medical CenterNote: Content may be edited for style and length.

 

via Electrical stimulation in brain bypasses senses, instructs movement — ScienceDaily

, , , ,

Leave a comment

[VIDEO] Post Stroke Foot Dorsiflexion: Using Electrical Stimulation to Reduce Tone & Promote Plasticity – YouTube

Further reading on electrophysiology and muscle contractions: http://strokemed.com/motor-behaviour-…

via  Post Stroke Foot Dorsiflexion: Using Electrical Stimulation to Reduce Tone & Promote Plasticity – YouTube

, , , , , , , , ,

Leave a comment

[WEB PAGE] Reconnecting the Disconnected: Restoring Movement in Paralyzed Limbs – Video

"Moving an arm can involve more than 50 different muscles," UA professor Andrew Fuglevand said. "Replicating how the brain naturally coordinates the activities of these muscles is extremely challenging."

“Moving an arm can involve more than 50 different muscles,” UA professor Andrew Fuglevand said. “Replicating how the brain naturally coordinates the activities of these muscles is extremely challenging.”

UA professor Andrew Fuglevand is using artificial intelligence to stimulate multiple muscles to elicit natural movement in ways previous methods have been unable to do.
Dec. 20, 2018

Andrew Fuglevand

Andrew Fuglevand

Scientists now know that the brain controls movement in people by signaling groups of neurons to tell the muscles when and where to move. Researchers also have learned it takes a complex orchestration of many signals to produce even seemingly simple body movements.

If any of these signals are blocked or broken, such as from a spinal cord injury or stroke, the messages from the brain to the muscles are unable to connect, causing paralysis. The person’s muscles are functional, but they no longer are being sent instructions.

Andrew Fuglevand, professor of physiology at the University of Arizona College of Medicine – Tucson and professor of neuroscience at the UA College of Science, has received a $1.2 million grant from the National Institutes of Health to study electrical stimulation of the muscles as a way to restore limb movements in paralyzed individuals. Fuglevand’s goal is to restore voluntary movement to a person’s own limbs rather than relying on external mechanical or robotic devices.

Producing a wide range of movements in paralyzed limbs has been unsuccessful so far because of the substantial challenges associated with identifying the patterns of muscle stimulation needed to elicit specified movements, Fuglevand explained.

“Moving a finger involves as many as 20 different muscles at a time. Moving an arm can involve more than 50 different muscles. They all work together in an intricate ‘dance’ to produce beautifully smooth movements,” he said. “Replicating how the brain naturally coordinates the activities of these muscles is extremely challenging.”

Recent advances in “machine learning,” or artificial intelligence, are making the impossible possible.

Fuglevand, who also is an affiliate professor of biomedical engineering and teaches neuroscience courses at the UA, is employing machine learning to mimic and replicate the patterns of brain activity that control groups of muscles. Tiny electrodes implanted in the muscles replay the artificially generated signals to produce complex movements.

“If successful, this approach would greatly expand the repertoire of motor behaviors available to paralyzed individuals,” he said.

“More than 5 million Americans are living with some form of paralysis, and the leading causes are stroke and spinal injury,” said Nicholas Delamere, head of the UA Department of Physiology. “New innovations in artificial intelligence, developed by scientists like Fuglevand and his team, are allowing them to decode subtle brain signals and make brain-machine interfaces that ultimately will help people move their limbs again.”

“The headway researchers have made in our understanding of artificial intelligence, machine learning and the brain is incredible,” said UA President Robert C. Robbins. “The opportunity to incorporate AI to brain-limb communication has life-changing potential, and while there are many challenges to optimize these interventions, we are really committed to making this step forward. I am incredibly excited to track Dr. Fuglevand’s progress with this new grant.”

Research reported in this release was supported by the National Institutes of Health, National Institute of Neurological Disorders and Stroke, under grant No. 1R01NS102259-01A1. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
A version of this article originally appeared on the UA Health Sciences website:https://opa.uahs.arizona.edu/newsroom/news/2018/reconnecting-disconnected-ua-physiology-professor-receives-12m-nih-grant-use-ai

 

via Reconnecting the Disconnected: Restoring Movement in Paralyzed Limbs | UANews

, , , , , , , ,

Leave a comment

[ARTICLE] Effect of the combination of motor imagery and electrical stimulation on upper extremity motor function in patients with chronic stroke: preliminary results – Full Text

 

The combination of motor imagery (MI) and afferent input with electrical stimulation (ES) enhances the excitability of the corticospinal tract compared with motor imagery alone or electrical stimulation alone. However, its therapeutic effect is unknown in patients with hemiparetic stroke. We performed a preliminary examination of the therapeutic effects of MI + ES on upper extremity (UE) motor function in patients with chronic stroke.

A total of 10 patients with chronic stroke demonstrating severe hemiparesis participated. The imagined task was extension of the affected finger. Peripheral nerve electrical stimulation was applied to the radial nerve at the spiral groove. MI + ES intervention was conducted for 10 days. UE motor function as assessed with the Fugl–Meyer assessment UE motor score (FMA-UE), the amount of the affected UE use in daily life as assessed with a Motor Activity Log (MAL-AOU), and the degree of hypertonia in flexor muscles as assessed with the Modified Ashworth Scale (MAS) were evaluated before and after intervention. To assess the change in spinal neural circuits, reciprocal inhibition between forearm extensor and flexor muscles with the H reflex conditioning-test paradigm at interstimulus intervals (ISIs) of 0, 20, and 100 ms were measured before and after intervention.

UE motor function, the amount of the affected UE use, and muscle hypertonia in flexor muscles were significantly improved after MI + ES intervention (FMA-UE: p < 0.01, MAL-AOU: p < 0.01, MAS: p = 0.02). Neurophysiologically, the intervention induced restoration of reciprocal inhibition from the forearm extensor to the flexor muscles (ISI at 0 ms: p = 0.03, ISI at 20 ms: p = 0.03, ISI at 100 ms: p = 0.01).

MI + ES intervention was effective for improving UE motor function in patients with severe paralysis.

Upper motor dysfunction is a common problem in patients with stroke and disrupts activities of daily living and eventually worsens quality of life.1,2 Recently, several rehabilitation approaches have been developed to improve upper extremity (UE) motor function. Previous research has shown that intensive use of the paretic upper limb contributes to improved motor function, even though the motor recovery period has already passed.36 However, intensive use of the paretic upper limb is impossible for patients with severe upper limb paralysis, because they cannot voluntarily control the paretic hand. Therefore, other rehabilitative approaches for severely impaired patients are needed. As an alternative approach, motor imagery (MI) can be applied to patients regardless of the degree of motor paralysis. MI is defined as a dynamic state during which the representation of a given motor act is internally rehearsed within working memory without any overt motor output.7 Functional imaging studies have revealed that brain activity during motor execution and MI is largely shared in motor networks, such as the primary motor area, supplementary motor area, and premotor area.810 Also, transcranial magnetic stimulation (TMS) studies reported that excitability of the corticospinal tract (CST) is significantly higher during MI in comparison with baseline.1115 Based on these observations, MI has been applied for rehabilitation of patients with hemiparetic stroke, and the positive therapeutic effects on UE motor function have been reported.1620 However, the effect size differs among the studies,19 and is lower with regard to motor recovery of the paretic hand.20 To obtain clinically significant improvement, ingenuity to strengthen the therapeutic effect of MI is thought to be necessary.

The combination of MI and afferent input with electrical stimulation (ES) is an approach to enhance the therapeutic effect of MI. The effectiveness of ES for modulation of the excitability of the CST and improvement of dexterity performance of the paretic hand has been reported in patients with mild to moderate paralysis.21,22 Moreover, the additive effect of MI and ES has been reported in healthy adults. Saito and colleagues reported that a combination of MI and peripheral nerve ES enhances the excitability of the CST compared with MI alone or ES alone.23 In addition, Kaneko and colleagues reported that the combination of MI and electrical muscular stimulation reproduces the excitability of the CST at levels similar to voluntary muscle contraction.24 However, its therapeutic effects for motor function in patients with stroke are unknown. Therefore, we performed a preliminary examination of the therapeutic effects of a combination of MI and peripheral nerve ES (MI + ES) on UE motor function in patients with severe paralysis. The aim of this study is to investigate the feasibility and potential of the therapeutic effect for future randomized controlled trials.[…]

 

Continue —> Effect of the combination of motor imagery and electrical stimulation on upper extremity motor function in patients with chronic stroke: preliminary results – Kohei Okuyama, Miho Ogura, Michiyuki Kawakami, Kengo Tsujimoto, Kohsuke Okada, Kazuma Miwa, Yoko Takahashi, Kaoru Abe, Shigeo Tanabe, Tomofumi Yamaguchi, Meigen Liu, 2018

                        figure

Figure 1. The experimental setup of the intervention with combination of motor imagery and electrical stimulation (MI + ES).

, , , , , , , , , , ,

Leave a comment

[WEB SITE] Electrically stimulating the brain may restore movement after stroke

June 18, 2018, University of California, San Francisco

stroke

Micrograph showing cortical pseudolaminar necrosis, a finding seen in strokes on medical imaging and at autopsy. H&E-LFB stain. Credit: Nephron/Wikipedia

UC San Francisco scientists have improved mobility in rats that had experienced debilitating strokes by using electrical stimulation to restore a distinctive pattern of brain cell activity associated with efficient movement. The researchers say they plan to use the new findings to help develop brain implants that might one day restore motor function in human stroke patients.

After a , roughly one-third of  recover fully, one-third have significant lingering  problems, and one-third remain virtually paralyzed, said senior author Karunesh Ganguly, MD, Ph.D., associate professor of neurology and a member of the UCSF Weill Institute for Neurosciences. Even patients who experience partial recovery often continue to struggle with “goal-directed” movements of the arms and hands, such as reaching and manipulating objects, which can be crucial in the workplace and in daily living.

“Our main impetus was to understand how we can develop implantable neurotechnology to help stroke patients,” said Ganguly, who conducts research at the San Francisco VA Health Care System. “There’s an enormous field growing around the idea of neural implants that can help neural circuits recover and improve function. We were interested in trying to understand the circuit properties of an injured brain relative to a healthy brain and to use this information to tailor neural implants to improve  after stroke.”

Over the past 20 years, neuroscientists have presented evidence that coordinated patterns of neural activity known as oscillations are important for efficient brain function. More recently, low-frequency oscillations (LFOs)—which were first identified in studies of sleep—have been specifically found to help organize the firing of neurons in the brain’s primary motor cortex. The motor cortex controls voluntary movement, and LFOs chunk the cells’ activity together to ensure that goal-directed movements are smooth and efficient.

In the new study, published in the June 18, 2018 issue of Nature Medicine, the researchers first measured neural activity in rats while the animals reached out to grab a small food pellet, a task designed to emulate human goal-directed movements. They detected LFOs immediately before and during the action, which inspired the researchers to investigate how these activity patterns might change after stroke and during recovery.

To explore these questions, they caused a stroke in the rats that impaired the animals’ movement ability, and found that LFOs diminished. In rats that were able to recover, gradually making faster and more precise movements, the LFOs also returned. There was a strong correlation between recovery of function and the reemergence of LFOs. Animals that fully recovered had stronger low-frequency activity than those that partially recovered, and those that didn’t recover had virtually no low-frequency activity.

To try to boost recovery, the researchers used electrodes to both record activity and deliver a mild electrical current to the rats’ brains, stimulating the area immediately surrounding the center of the . This stimulation consistently enhanced LFOs in the damaged area and appeared to improve motor function: when the researchers delivered a burst of electricity right before a rat made a movement, the rat was up to 60 percent more accurate at reaching and grasping for a food pellet.

“Interestingly, we observed this augmentation of LFOs only on the trials where stimulation was applied,” said Tanuj Gulati, Ph.D., a postdoctoral researcher in the Ganguly lab who is co-first author of the study, along with Dhakshin Ramanathan, MD, Ph.D., now assistant professor of psychiatry at UC San Diego, and Ling Guo, a neuroscience graduate student at UCSF.

“We are not creating a new frequency, we are amplifying the existing frequency,” added Ganguly. “By amplifying the weak low-frequency oscillations, we are able to help organize the task-related . When we delivered the electrical current in step with their intended actions, motor control actually got better.”

The researchers wanted to know whether their findings might also apply to humans, so they analyzed recordings made from the surface of the brain of an epilepsy patient who had suffered a stroke that had impaired the patient’s arm and hand movements. The recordings revealed significantly fewer LFOs than recordings made in two epilepsy patients who hadn’t had a stroke. These findings suggest that, just as in rats, the stroke had caused a loss of low-frequency  that impaired the patient’s movement.

Physical therapy is the only treatment currently available to aid stroke patients in their recovery. It can help people who are able to recover neurologically get back to being fully functional more quickly, but not those whose stroke damage is too extensive. Ganguly hopes that electrical brain stimulation can offer a much-needed alternative for these latter patients, helping their brain circuits to gain better control of motor neurons that are still functional. Electrical  stimulation is already widely used to help patients with Parkinson’s disease and epilepsy, and Ganguly believes stroke patients may be the next to benefit.

 Explore further: Electrical nerve stimulation could help patients regain motor functions sooner

More information: Low-frequency cortical activity is a neuromodulatory target that tracks recovery after stroke, Nature Medicine (2018). www.nature.com/articles/s41591-018-0058-y

via Electrically stimulating the brain may restore movement after stroke

, , , , , , , , ,

Leave a comment

[Abstract] Effect of Transcutaneous Electrical Nerve Stimulation (TENS) on spasticity in adults with stroke: A systematic review and meta-analysis

Abstract

Objectives

1. To determine the effect of transcutaneous electrical nerve stimulation (TENS) on post-stroke spasticity. 2a. To determine the effect of different parameters (intensity, frequency, and duration) of TENS on spasticity reduction in adults with stroke; 2b. To determine the influence of time since stroke on the effectiveness of TENS on spasticity.

Data sources

PubMed, PEDro, CINAHL, Web of Science, CENTRAL and EMBASE databases were searched from inception to March 2017.

Study Selection

Randomized controlled trial (RCT), quasi RCT and non-RCT were included if: (a) they evaluated the effects of TENS for the management of spasticity in participants with acute/sub-acute/chronic stroke using clinical and neurophysiological tools; and (b) TENS was delivered either alone or as an adjunct to other treatments.

Data extraction

Two authors independently screened and extracted data from 15 of the 829 studies retrieved through the search using a pilot tested pro-forma. Disagreements were resolved through discussion with other authors. Quality of studies was assessed using Cochrane risk of bias criteria.

Data synthesis

Meta-analysis was performed using a random-effects model which showed (a) TENS along with other physical therapy treatments was more effective in reducing spasticity in the lower limbs compared to placebo TENS (SMD -0.64, 95% CI -0.98 to -0.31; p = 0.0001; I2 =17%); and (b) TENS, when administered along with other physical therapy treatments, was effective in reducing spasticity when compared to other physical therapy interventions alone (SMD -0.83, 95% CI -1.51 to -0.15; p =0.02; I2 = 27%). There were limited studies to evaluate the effectiveness of TENS for upper limb spasticity.

Conclusion

There is strong evidence that TENS as an adjunct is effective in reducing lower limb spasticity when applied for more than 30 minutes over nerve or muscle belly in chronic stroke survivors. (Review protocol registered at PROSPERO: CRD42015020151).

 

via Effect of Transcutaneous Electrical Nerve Stimulation (TENS) on spasticity in adults with stroke: A systematic review and meta-analysis – Archives of Physical Medicine and Rehabilitation

, , , , , ,

Leave a comment

[WEB SITE] Implant dissolves into the body after it speeds nerve healing – VIDEO

Scientists have developed the first ever bioresorbable electronic medicine: a biodegradable wireless implant that speeds nerve regeneration and improves the healing of damaged nerves.


In a study with rats, the device delivered regular pulses of electricity to damaged peripheral nerves after a surgical repair process, accelerating the regrowth of nerves in the rats’ legs and enhancing the ultimate recovery of muscle strength and control.

The wireless device, about the size of a dime and the thickness of a sheet of paper, operates for about two weeks before naturally absorbing into the body.

The scientists envision that such transient engineered technologies could one day complement or replace pharmaceutical treatments for a variety of medical conditions in humans.

This type of technology, which the researchers refer to as a “bioresorbable electronic medicine,” provides therapy and treatment over a clinically relevant period of time and directly at the site where it’s needed, thereby reducing side effects or risks associated with conventional, permanent implants.

OPEN THE WINDOW

“These engineered systems provide active, therapeutic function in a programmable, dosed format and then naturally disappear into the body, without a trace,” says co-senior author John A. Rogers, professor of materials science and engineering, biomedical engineering and neurological surgery in the McCormick School of Engineering and Northwestern University Feinberg School of Medicine. “This approach to therapy allows one to think about options that go beyond drugs and chemistry.”

While researchers haven’t tested the device in humans, the findings offer promise as a future therapeutic option for nerve injury patients. For cases requiring surgery, standard practice is to administer some electrical stimulation during the surgery to aid recovery. But until now, doctors have lacked a means to continuously provide that added boost at various time points throughout the recovery and healing process.

“We know that electrical stimulation during surgery helps, but once the surgery is over, the window for intervening is closed,” says co-senior author Wilson “Zack” Ray, an associate professor of neurosurgery, of biomedical engineering, and of orthopedic surgery at Washington University in St. Louis. “With this device, we’ve shown that electrical stimulation given on a scheduled basis can further enhance nerve recovery.”

https://giphy.com/embed/oyiXMeIUYJ7p8mwxCD

via GIPHY

Over the past eight years, Rogers and his lab have developed a complete collection of electronic materials, device designs, and manufacturing techniques for biodegradable devices with a broad range of options that offer the potential to address unmet medical needs.

When Ray and his colleagues at Washington University identified the need for electrical stimulation-based therapies to accelerate wound healing, Rogers and colleagues at Northwestern went to their toolbox and designed and developed a thin, flexible device that wraps around an injured nerve and delivers electrical pulses at selected time points for days before the device harmlessly degrades in the body.

A transmitter outside the body that acts much like a cellphone-charging mat powers and controls the device wirelessly. Rogers and his team worked closely with the Washington University team throughout the development process and animal validation.

The Washington University researchers then studied the bioresorbable electronic device in rats with injured sciatic nerves. This nerve sends signals up and down the legs and controls the hamstrings and muscles of the lower legs and feet.

They used the device to provide one hour per day of electrical stimulation to the rats for one, three, or six days or no electrical stimulation at all, and then monitored their recovery for the next 10 weeks.

BEYOND THE NERVOUS SYSTEM

The findings show that any electrical stimulation was better than none at all at helping the rats recover muscle mass and muscle strength. Further, the more days of electrical stimulation the rats received, the more quickly and thoroughly they recovered nerve signaling and muscle strength. Researchers found no adverse biological effects from the device and its reabsorption.

“Before we did this study, we weren’t sure that longer stimulation would make a difference, and now that we know it does, we can start trying to find the ideal time frame to maximize recovery,” Ray says. “Had we delivered electrical stimulation for 12 days instead of six, would there have been more therapeutic benefit? Maybe. We’re looking into that now.”

By varying the composition and thickness of the materials in the device, Rogers and colleagues can control the precise number of days it remains functional before the body absorbs it.

“THIS NOTION OF TRANSIENT ELECTRONIC DEVICES HAS BEEN A TOPIC OF DEEP INTEREST IN MY GROUP FOR NEARLY 10 YEARS—A GRAND QUEST IN MATERIALS SCIENCE, IN A SENSE.”

New versions can provide electrical pulses for weeks before degrading. The ability of the device to degrade in the body takes the place of a second surgery to remove a non-biodegradable device, thereby eliminating additional risk to the patient.

“We engineer the devices to disappear,” Rogers says. “This notion of transient electronic devices has been a topic of deep interest in my group for nearly 10 years—a grand quest in materials science, in a sense. We are excited because we now have the pieces—the materials, the devices, the fabrication approaches, the system-level engineering concepts—to exploit these concepts in ways that could have relevance to grand challenges in human health.”

The research study also showed the device can work as a temporary pacemaker and as an interface to the spinal cord and other stimulation sites across the body. These findings suggest broad utility, beyond just the peripheral nervous system.

Source: Northwestern University

 

via Implant dissolves into the body after it speeds nerve healing – Futurity

, , , , , ,

Leave a comment

%d bloggers like this: