Effects of Low Frequency TENS and Therapeutic Ultrasound in Post-stroke Shoulder Pain

Cerebral vascular accidents (CVAs) are the second most common cause of death in developed nations, according to the World Health Organization.It is a significant factor in disability because it causes paralysis and cognitive impairments in the population that survives. According to data from the literature, 25% of stroke patients pass away within a few weeks.Shoulder pain is exasperating complication after stroke and responsible for the longer stay in the rehabilitation department. The incidence varies from 9%-40.Post-Stroke shoulder pain decreased functional outcome, and quality of life.Post-stroke muscle weakness and spasticity lead to shoulder instability and immobility. The etiology of shoulder pain after stroke is multifactorial complex regional pain syndrome, shoulder joint subluxation, adhesive capsulitis, spasticity, and shoulder muscles weakness.Etiological intricacy makes it necessary to use a stroke-specific approach rather than always expanding the musculoskeletal knowledge base.

Presence of hemiplegic shoulder pain is strongly associated poor recovery of arm function in the first 12 weeks after stroke.It may be a sign of brachial plexus damage if there are aberrant motor recovery patterns, spasticity or particularly severe localized atrophy. A pre-existing ailment like osteoarthritis may worsen as a result of improper management of a hemiplegic limb. Therefore, hemiplegic shoulder pain may be caused by pre-morbid shoulder illness.Physical therapy has been shown to be very effective in treating post-stroke shoulder pain. A variety of techniques and treatment modalities are use around the world to alleviate the post-stroke shoulder pain. Of particular interest to this research are two electrotherapy modalities low frequency transcutaneous electrical stimulation and Therapeutic Ultrasound will be treatment option.

TENS therapy together with conventional rehabilitation could be used as a good alternative therapy in patients with hemiplegic shoulder pain.There is wide spread use of TENS throughout health care and it is a common treatment modality for musculoskeletal pain. The TENS settings are based on the gate control theory of pain. TENS is agree to produce a significant reduction in pain. Transcutaneous electrical nerve stimulation (TENS) is an inexpensive, noninvasive, self-administered technique that is use as an adjunct to medication. TENS treatment is rarely associated with negative side effects and has been reported to be effective in patients with neuropathic pain. Most studies evaluated the effect of high-frequency or low-frequency TENS (LF-TENS).The study aim is to investigate the effect of LF-TENS on the treatment of neuropathic pain in patients with post-stroke shoulder pain.

Therapeutic Ultrasound a physical therapy agent commonly used to increase temperature in deep tissue. The biologic effects observed when mammalian tissues are expose to ultrasound include changes in blood flow rates, tissue metabolism, the extensibility of connective tissue, and tissue regeneration. Thermal effects of therapeutic ultrasound reduces pain, swelling and improve ROM. When treating knee, shoulder, and hip pain, therapeutic ultrasound is routinely utilize in conjunction with other physiotherapeutic methods. The body of research on knee arthritis is very strong, and there is some evidence that therapeutic ultrasound is effective although there is debate about whether ultrasound should be delivered continuously or in pulses. Although ultrasound therapy alone may not have much of an effect on functional improvement, it can be a fair adjunct to take into account when combined with other widely used modalities.

The current study aims to evaluate and generalize the comparative effects of low frequency transcutaneous electrical stimulation combined with therapeutic ultrasound and therapeutic ultrasound and low frequency TENS alone in our settings. It is suggested that low frequency TENS with therapeutic ultrasound would provide a clinically and statistically significant benefit over a therapeutic ultrasound and low frequency TENS alone for patients with functional disability in post stroke shoulder pain. The purpose of the study is to determine an appropriate and cost-effective rehabilitation protocol for patients with functional disability in post-stroke shoulder pain.

Literature review.

A randomize clinical trial conducted in 2010 to evaluate the effect of therapeutic modalities on patients with post stroke shoulder pain. 45 patients were selected randomly with post stroke shoulder pain. Patients were randomly assigned into group A and group B .Group A patients treated by TENS, NASIAD, Exercise and ADLs instructions and group B received therapeutic ultrasound, NSAID, Exercise and ADLs instructions for 5 visits after every two weeks interval. The study recommended that TENS is more effective than therapeutic ultrasound.

A single blind, randomized controlled trial was conducted in 2017 determine the effect of EMG-triggered neuromuscular electrical stimulation with bilateral arm training on hemiplegic shoulder pain and arm function after stroke. Thirty-eight patients with post-stroke shoulder pain were randomized to EMG-triggered NMES or TENS. Both groups received electrical stimulation followed by bilateral arm training 3 times a week for 4 weeks. Primary outcome measures included a vertical numerical rating scale supplemented by a face rating scale and the short form of the Brief Pain Inventory. Secondary outcome measures were the upper extremity subscale of the Fugl-Meyer rating and pain-free passive shoulder range of motion. All outcomes were measured before treatment, post treatment. Two-way mixed repeated- measures ANOVAs were used to examine treatment effects. EMG-triggered NMES with bilateral arm training showed greater immediate and sustained effects than TENS with bilateral arm training on shoulder pain and damage in chronic and subacute stroke patients with hemiplegic shoulder pain.

A research was conducted to evaluate the effectiveness of high-intensity laser therapy in the treatment of post-stroke patients with hemiplegic shoulder pain. A study was designed as a prospective, randomize clinical trial. Forty-four patients with hemiplegic shoulder pain accompanied by partial thickness rotator cuff tear were randomly divided into high intensity lesser therapy and control groups. High intensity lesser therapy group and control group treated with multidisciplinary rehabilitation and therapeutic exercise program in addition to this three session of intervention per week for three weeks received by high intensity lesser therapy group. High intensity lesser therapy treatment significantly decrease pain ,increase range of motion and functional independence as compare to control group.