Efficiency of Neuromuscular Electrical Stimulation and Transcutaneous Nerve Stimulation on Hemiplegic Shoulder Pain: A Randomized Controlled Trial.

OBJECTIVE: To compare the efficacy of neuromuscular electrical stimulation (NMES) and transcutaneous nerve stimulation (TENS) on hemiplegic shoulder pain (HSP). DESIGN: This is a prospective randomized controlled trial. SETTING: A rehabilitation hospital. PARTICIPANTS: Participants (N=90) were randomized into NMES (n=36), TENS (n=36), or control groups (n=18). INTERVENTIONS: NMES (15Hz, pulse width 200µs) was applied to supraspinatus and deltoids (medial and posterior parts), whereas TENS (100Hz, pulse width 100µs) was used on the same areas. The surface electrodes were placed near the motor points of the supraspinatus and medial or posterior bundle of deltoids. The 4-week treatment consisted of 20 sessions, each session composed of 1 hour of stimulation per day. Routine rehabilitation program without any stimulation was administered to the control and the NMES/TENS groups. Numerical rating scale (NRS), active/passive range of motion (AROM/PROM) of shoulder, upper extremity Fugl-Meyer Assessment (FMA), modified Ashworth scale (MAS), Barthel Index (BI), and stroke-specific quality of life scale (SSQOLS) were assessed in a blinded manner at baseline, 2, 4, and 8 weeks after treatment, respectively. MAIN OUTCOME MEASURES: The primary endpoint was the improvement from baseline in NRS for HSP at 4 weeks. RESULTS: NRS scores in NMES, TENS, and control groups had decreased by 2.03, 1.44, and 0.61 points, respectively after 4 weeks of treatment, with statistically significant differences among the 3 groups (P<.001). The efficacy of the NMES group was significantly better than that of the TENS group (P=.043). Moreover, the efficacy of NMES and TENS groups was superior to that of the control group (P<.001, P=.044, respectively). The differences in the therapeutic efficacy on shoulder AROM/PROM, FMA, MAS, BI, and SSQOLS scores were not significant among the 3 groups. CONCLUSIONS: TENS and NMES can effectively improve HSP, the efficacy of NMES being distinctly superior to that of TENS in maintaining long-term analgesia. However, NMES was not more efficacious than the TENS or control group in improving the shoulder joint mobility, upper limb function, spasticity, the ability of daily life activity, and stroke-specific quality of life in HSP patients.

Peripheral Nerve Stimulation for Chronic Shoulder Pain: A Proof of Concept Anatomy Study.

OBJECTIVES: Although spinal cord and dorsal root ganglia stimulation may be effective for managing regional pain syndromes, a more targeted approach is perhaps more appealing for discrete anatomical structures. Chronic shoulder pain is a common musculoskeletal problem with significant socioeconomic impact. A peripheral nerve stimulation of the axillary and suprascapular nerves may prove to be effective as a long-term solution for this indication. In anticipation of the future experimental research and clinical utilization, a sound methodology for the lead placement was developed, and its feasibility is tested in a cadaveric study. MATERIALS AND METHODS: Normal anatomy was corroborated with ultrasound scans of live models and cadaver specimens. A step-by-step ultrasound-guided implantation technique was designed. The procedure was completed targeting both the axillary and suprascapular nerves. The accuracy of the lead placement was confirmed by dissections. RESULTS: The implanted devices were found adjacent to the target nerves within 0.5-1 cm distance. CONCLUSIONS: The anatomical dissections confirmed the accuracy of ultrasound-guided placement of the lead. The described method is based on normal anatomy and appeared to be reproducible by following the outlined procedural steps.

Ipsilateral EEG mu rhythm reflects the excitability of uncrossed pathways projecting to shoulder muscles.

BACKGROUND: Motor planning, imagery or execution is associated with event-related desynchronization (ERD) of mu rhythm oscillations (8-13 Hz) recordable over sensorimotor areas using electroencephalography (EEG). It was shown that motor imagery involving distal muscles, e.g. finger movements, results in contralateral ERD correlating with increased excitability of the contralateral corticospinal tract (c-CST). Following the rationale that purposefully increasing c-CST excitability might facilitate motor recovery after stroke, ERD recently became an attractive target for brain-computer interface (BCI)-based neurorehabilitation training. It was unclear, however, whether ERD would also reflect excitability of the ipsilateral corticospinal tract (i-CST) that mainly innervates proximal muscles involved in e.g. shoulder movements. Such knowledge would be important to optimize and extend ERD-based BCI neurorehabilitation protocols, e.g. to restore shoulder movements after stroke. Here we used single-pulse transcranial magnetic stimulation (TMS) targeting the ipsilateral primary motor cortex to elicit motor evoked potentials (MEPs) of the trapezius muscle. To assess whether ERD reflects excitability of the i-CST, a correlation analysis between between MEP amplitudes and ipsilateral ERD was performed. METHODS: Experiment 1 consisted of a motor execution task during which 10 healthy volunteers performed elevations of the shoulder girdle or finger pinching while a 128-channel EEG was recorded. Experiment 2 consisted of a motor imagery task during which 16 healthy volunteers imagined shoulder girdle elevations or finger pinching while an EEG was recorded; the participants simultaneously received randomly timed, single-pulse TMS to the ipsilateral primary motor cortex. The spatial pattern and amplitude of ERD and the amplitude of the agonist muscle's TMS-induced MEPs were analyzed. RESULTS: ERDs occurred bilaterally during both execution and imagery of shoulder girdle elevations, but were lateralized to the contralateral hemisphere during finger pinching. We found that trapezius MEPs increased during motor imagery of shoulder elevations and correlated with ipsilateral ERD amplitudes. CONCLUSIONS: Ipsilateral ERD during execution and imagery of shoulder girdle elevations appears to reflect the excitability of uncrossed pathways projecting to the shoulder muscles. As such, ipsilateral ERD could be used for neurofeedback training of shoulder movement, aiming at reanimation of the i-CST.

Comparison of photobiomodulation therapy and suprascapular nerve-pulsed radiofrequency in chronic shoulder pain: a randomized controlled, single-blind, clinical trial.

Shoulder pain can be difficult to treat due to its complex anatomic structure, and different treatment methods can be used. We aimed to examine the efficacy of photobiomodulation therapy (PBMT) and suprascapular nerve (SSN)-pulsed radiofrequency (RF) therapy. In this prospective, randomized, controlled, single-blind study, 59 patients with chronic shoulder pain due to impingement syndrome received PBMT (group H) or SSN-pulsed RF therapy (group P) in addition to exercise therapy for 14 sessions over 2 weeks. Records were taken using visual analog scale (VAS), Shoulder Pain and Disability Index (SPADI), and Nottingham Health Profile (NHP) scoring systems for pretreatment (PRT), posttreatment (PST), and PST follow-up at months 1, 3, and 6. There was no statistically significant difference in initial VAS score, SPADI, and NHP values between group H and group P (p > 0.05). Compared to the values of PRT, PST, and PST at months 1, 3, and 6, VAS, SPADI, and NHP values were statistically significantly lower in both groups (p < 0.001). There was no statistically significant difference at all measurement times in VAS, SPADI, and NHP between the two groups. We established that PBMT and SSN-pulsed RF therapy are effective methods, in addition to exercise therapy, in patients with chronic shoulder pain. PBMT seems to be advantageous compared to SSN-pulsed RF therapy, as it is a noninvasive method.

[Lateralization of EEG Patterns in Humans during Motor Imagery of Arm Movements in the Brain-Computer Interface].

In this study EEG patterns ofsensorimotor rhythm were examined in 10 healthy subjects while perform- ing motor imagery of upper arm and hand movements. Participants received visual feedback through so called brain-computer interface (BCI) used for detection of user-specific spatio-temporal.EEG patterns associated with performed mental tasks. During the course study,.all of the subjects were able to modulate their sensorimotor EEG by performing motor imagery of shoulder and fingers movements. Patterns during imagery of shoulder movements were found to have more pronounced contralateral localization, than those during hand movements' imagery. That led to significantly better classification accuracies of the most lateralized patterns when discriminating between left and right hand (72 and 58% corresponding to shoulder and hand motor imagery). Value of difference of patterns' lateralization indexes had shown strong correlation with classification accuracy, suggests it could be used as a good ref- erence mark for.choosing optimal motor imagery tasks for BCI application.

Intraoperative brief electrical stimulation (BES) for prevention of shoulder dysfunction after oncologic neck dissection: study protocol for a randomized controlled trial.

BACKGROUND: Shoulder pain and dysfunction are common after oncologic neck dissection for head and neck cancer (HNC), due to traction, compression, and devascularization injuries to the spinal accessory nerve (SAN). Shoulder pain and dysfunction can hinder postoperative rehabilitation and hygiene, activities of daily living (ADLs), and return to work after treatment for HNC. Due to the rising incidence of human papillomavirus (HPV)-associated oropharyngeal cancer, patients are often diagnosed in the third or fourth decade of life, leaving many potential working years lost if shoulder dysfunction occurs. Brief electrical stimulation (BES) is a novel technique that has been shown to enhance and accelerate neuronal regeneration after injury through a brain-derived neurotrophic growth factor (BDNF)-driven molecular pathway in multiple peripheral nerves in both humans and animals. METHODS/DESIGN: This is a randomized controlled trial testing the effect of intraoperative BES on postoperative shoulder pain and dysfunction. All adult participants with a new diagnosis of HNC undergoing surgery with neck dissection, including Level IIb and postoperative radiotherapy, will be enrolled. Participants will undergo intraoperative BES after completion of neck dissection for 60 min continuously at 20 Hz, 3 to 5 V, in 100-msec pulses. Postoperatively, participants will be evaluated using the Constant-Murley Shoulder Score, a scale that assesses shoulder pain, ADLs, strength, and range of motion. Secondary outcomes measured will include nerve conduction studies (NCS) and electromyographic (EMG) studies, as well as scores on the Oxford Shoulder Score (OSS), the Neck Dissection Impairment Index (NDII), and the University of Washington Quality of Life (UW-QOL) score. Primary and secondary outcomes will be assessed at 6 weeks, 3 months, 6 months, and 12 months. DISCUSSION: The objective of this study is to evaluate the effect of BES on postoperative clinical and objective shoulder functional outcomes and pain after oncologic neck dissection. BES has been shown to be successful in accelerating peripheral nerve regeneration in both animal and human participants in multiple different peripheral nerves. If successful, this technique may provide an adjunctive prevention option for shoulder pain and dysfunction in HNC patients. TRIAL REGISTRATION: NCT02268344: 17 October 2014.

A cadaveric study to determine the minimum volume of methylene blue to completely color the nerves of brachial plexus in cats. An update in forelimb and shoulder surgeries.

PURPOSE: To determine the minimum volume of methylene blue (MB) to completely color the brachial plexus (BP) nerves, simulating an effective anesthetic block in cats. METHODS: Fifteen adult male cat cadavers were injected through subscapular approach with volumes of 2, 3, 4, 5 and 6 ml in both forelimbs, for a total of 30 brachial plexus blocks (BPB). After infusions, the specimens were carefully dissected preserving each nervous branch. The measurement of the effective area was indicated by the impregnation of MB. Nerves were divided into four segments from the origin at the spinal level until the insertion into the thoracic limb muscles. The blocks were considered effective only when all the nerves were strongly or totally colored. RESULTS: Volumes of 2, 3 and 4 ml were considered insufficient suggesting a failed block, however, volumes of 5 and 6 ml were associated with a successful block. CONCLUSIONS: The injection of methylene blue, in a volume of 6 ml, completely colored the brachial plexus. At volumes of 5 and 6 ml the brachial plexus blocks were considered a successful regional block, however, volumes of 2, 3 and 4 ml were considered a failed regional block.

A cadaveric study to determine the minimum volume of methylene blue to completely color the nerves of brachial plexus in cats. An update in forelimb and shoulder surgeries

PURPOSE: To determine the minimum volume of methylene blue (MB) to completely color the brachial plexus (BP) nerves, simulating an effective anesthetic block in cats. METHODS: Fifteen adult male cat cadavers were injected through subscapular approach with volumes of 2, 3, 4, 5 and 6 ml in both forelimbs, for a total of 30 brachial plexus blocks (BPB). After infusions, the specimens were carefully dissected preserving each nervous branch. The measurement of the effective area was indicated by the impregnation of MB. Nerves were divided into four segments from the origin at the spinal level until the insertion into the thoracic limb muscles. The blocks were considered effective only when all the nerves were strongly or totally colored. RESULTS: Volumes of 2, 3 and 4 ml were considered insufficient suggesting a failed block, however, volumes of 5 and 6 ml were associated with a successful block. CONCLUSIONS: The injection of methylene blue, in a volume of 6 ml, completely colored the brachial plexus. At volumes of 5 and 6 ml the brachial plexus blocks were considered a successful regional block, however, volumes of 2, 3 and 4 ml were considered a failed regional block. .

Spinal accessory neuropathy associated with deep tissue massage: a case report.

Spinal accessory neuropathy (SAN) causes impaired arm mobility and pain. The spinal accessory nerve is often injured during surgical procedures such as neck dissection for tumor resection or cervical lymph node biopsy. Other traumatic injuries may also occur. SAN causes weakness of the trapezius muscle and, less frequently, of the sternocleidomastoid muscle. The clinical consequence of trapezius muscle weakness includes impaired stability of the scapula leading to upper limb dysfunction and pain. We present a rare and illustrative case of SAN associated with deep tissue massage leading to scapular winging and droopy shoulder as a result of weakness of the trapezius muscle.

Somatotopical relationships between cortical activity and reflex areas in reflexology: a functional magnetic resonance imaging study.

We examined the somatotopical relationship between cortical activity and sensory stimulation of reflex areas in reflexology using functional magnetic resonance imaging. Three reflex areas on the left foot, relating to the eye, shoulder, and small intestine were stimulated during the experiment. A statistical analysis showed that reflexological stimulation of the foot reflex areas corresponding to the eye, shoulder, and small intestine activated not only the somatosensory areas corresponding to the foot, but also the somatosensory areas corresponding to the eye, shoulder, and small intestine or neighboring body parts. Thus, the findings showed that reflexological stimulation induced a somatosensory process corresponding to the stimulated reflex area and that a neuroimaging approach can be used to examine the basis of reflexology effects.

A new technique for regional anesthesia for arthroscopic shoulder surgery based on a suprascapular nerve block and an axillary nerve block: an evaluation of the first results.

PURPOSE: We propose a new technique of regional anesthesia that combines suprascapular nerve block (SSNB) and axillary nerve block (ANB) in arthroscopic shoulder surgery. METHODS: Twenty consecutive patients undergoing arthroscopic procedures for shoulder cuff diseases were included in the trial. SSNB was performed by introducing the stimulating needle approximately 2 cm medial to the medial border of the acromion and about 2 cm cranial to the superior margin of the scapular spine until supraspinatus or infraspinatus muscle contractions were elicited. Following negative aspiration, 15 mL of a mixture of 2% lidocaine (5 mL) and 0.5% levobupivacaine (10 mL) was injected. ANB was performed; a line was drawn between the lateral-posterior angle of the acromion and the olecranon tip of the elbow. The location was about 2 cm cranial to the convergence of this line with the perpendicular line from the axillary fold. The needle was introduced approximately 2 cm cranial to this crossing point to elicit deltoid muscle contractions, and another 15 mL of the same anesthetic mixture was injected. Five mL of the same mixture was injected into each portal of the arthroscopic area. During surgery, patients were sedated with the use of midazolam. General anesthesia was not performed. Acceptance of the technique was assessed through a postsurgical survey of those treated. RESULTS: No serious complications occurred. None of the patients required opiates, analgesics, or general anesthesia during the surgical procedure. Postoperative pain control, which was assessed using a visual analog scale, was effective during the observation time. The total demand for nonopiate analgesics during the first 24 postoperative hours was negligible. Patient satisfaction and comfort were satisfactory. CONCLUSIONS: Combining SSNB and ANB is an effective and safe technique for intraoperative anesthesia and postoperative analgesia for certain procedures of shoulder arthroscopic surgery.

Mentally represented motor actions in normal aging II. The influence of the gravito-inertial context on the duration of overt and covert arm movements.

Here, we address the question of whether normal aging influences action representation by comparing the ability of 14 young (age: 23.6 +/- 2.1 years) and 14 older (age: 70.1 +/- 4.5 years) adults to mentally simulate arm movements under a varying dynamic context. We conducted two experiments in which we experimentally manipulated the gravity and inertial components of arm dynamics: (i) unloaded and loaded vertical arm movements, rotation around the shoulder joint, (ii) unloaded and loaded horizontal arm movements, rotations around the shoulder and elbow joints, in two directions (inertial anisotropy phenomenon). The main findings indicated that imagery ability was equivalent between the two groups of age for the unloaded arm movements, but better for the young than the older group, for the loaded arm movements. For the horizontal movements, we found better imagery ability for the young than the older adults for both movement directions and loads. Finally, young and old adults showed low (<8%)-temporal variability for both overt and covert arm movements in all conditions. Our findings showed a specific decline of action representation in the aging brain and suggest that internal models of action become imprecise with advance in age. This is not exact to say that there is a severe impairment of motor prediction in old adults as they can mentally represent their arm movements with high-temporal consistency. Finally, we propose that motor imagery could be used as a therapeutic tool for motor rehabilitation in aged adults.

Neural mechanisms involved in the functional linking of motor cortical points.

We sought to understand the basic neural processes involved in the functional linking of motor cortical points. We asked which of the two basic neural mechanisms, excitation or inhibition, is required to functionally link motor cortical points. In the ketamine-anaesthetized cat, a microstimulation electrode was positioned at a point (control point) that was identified by the following three characteristics of the EMG responses: the muscle(s) activated at threshold, any additional muscles recruited by supra-threshold stimulation, and their relative latency. A second distinct point (test point) producing activation of a muscle at a different joint was then identified. At this test cortical point the GABA(A) receptor antagonist bicuculline was ejected iontophoretically, while stimulating the control point near threshold. A combined response was elicited consisting of the response normally elicited at the control point plus that elicited at the test point. Thus, an artificial muscle synergy was produced following disinhibition of the test point. This was never the case when glutamate was ejected at the test point, even when supra-threshold stimuli were used at the control point. Therefore, simply increasing the excitability of a cortical point was not sufficient to release the muscle(s) represented at that point into a muscle synergy. Kynurenate, a broadly acting excitatory amino acid receptor antagonist, ejected at the bicuculline point reversed the effect of bicuculline. This shows that the release phenomenon was mediated synaptically and was not due to spread of the stimulating current. We suggest that release from inhibition may be one of the neural mechanisms involved in functionally linking motor cortical points. This functional linking may be part of the ensemble of motor cortical mechanisms involved in recruitment of muscle synergies.

Changes in the hemiparetic limb with training. I. Torque output.

The study concerns eleven patients who had suffered from a cerebro-vascular accident (CVA) less than 6 months previously and who were hospitalized for treatment. In addition to their multidisciplinary rehabilitation treatments, the patients consented to participate in an electromyographic (EMG) biofeedback program designed to increase their shoulder activity. From blocks of five individual isometric contractions, curves of both the mean torque and of its standard deviation (SD) were generated and from each of these, a mean value was obtained. These two measures were used to analyze the effects on the biofeedback training had induced on shoulder activity. The training induced negligible changes on the contralateral (CL) side. The mean torque value for the group was 31.02 post vs 30.99 Nm pre-training. However, for the hemiplegic (HEMI) limbs, some patients showed improvement while others did not. The treatment was considered a success when the mean torque values obtained in the last 2/3 of the training or at the post-training session were > or = 1.5 the values obtained during the pre-training session. Based on this criteria, it was found that six out of eleven patients did improve their muscular activity through the training. Among these, the improvement of four was greater during the 2/3 session than that observed at the post-training session. The six successful patients were found to have a pre-training upper extremity Fugl-Meyer score < or = 13. Two patients had a similar pre-training score of 11, and met the criteria of success, but the younger patient performed better than the older one. Patients with scores of 20 and higher did not meet the 1.5 criteria. A correlation (r = 0.80) was found between post/pre ratios of Fugl-Meyer scores and those of the mean torque: the test thus seems to have a limited usefulness for assessing local changes such as the effects of the biofeedback treatment on the shoulder.

Changes in the hemiparetic limb with training. II. EMG signal.

Following a cerebro-vascular accident, motor deficits are usually associated with a selective atrophy of fast fatiguable muscle fibers. The reduction of output torque in spastic patients is considered to be caused by unfused twitches resulting from the reduction in the motor unit firing rate. To regain control of a paretic limb, these patients have to learn, through training, how to recruit an adequate number of intact motor units to generate the required functional movement. In hemiplegia, intra-subject variability makes difficult the assessment of the effects of any therapy treatments. Our objective here was thus to address the problem of the data variability and to analyze the electromyographic signal obtained from hemiplegic patients under biofeedback training. The experimental situation chosen was a very isolated but controlled motor activity (an isometric shoulder forward flexion). The results show that after training, 5 out of 11 patients could produce EMG signal from their affected deltoid whose mean value was 50% greater than before the training, while no appreciable change was observed for their unaffected deltoid. While these EMG changes on the HEMI side are correlated with greater torque output, the coefficient of correlation is slightly smaller after than before the training (r = 0.87 vs 0.89). It can be hypothesized that while the training was directed toward the deltoid, the patients in some ways developed new strategies for contracting their shoulder.

Differential formation of topographic maps on the cerebral cortex and superior colliculus of the mouse by temporally correlated tactile- tactile and tactile-visual inputs.

Coincident electrical activity of nerve fibres seems to play a fundamental role in the development of ordered connections in the CNS. To test this hypothesis on the formation of topographic maps we connected two cutaneous regions of the body of newborn mice by implanting an artificial bridge of pig hair. Through this procedure we produced the mechanical fusion of the ear with either the shoulder or the nose. In these conditions the ear not only was connected with shoulder or nose, but was also in relation with the nasal or the inferior portion of visual space. Therefore the probability of temporally correlated tactile-tactile inputs (ear-shoulder or ear-nose) as well as tactile-visual inputs (ear-inferior or ear-nasal visual space) increased. By recording from the primary somatosensory cortex and superior colliculus, we found that the formation of topographic maps was based on different principles. The somatosensory cortex developed in terms of tactile-tactile correlated inputs, showing somatosensory neurons with receptive fields extending through the fused parts of the body. Conversely, the superior colliculus processed tactile-visual correlated inputs; we found somatosensory-visual bimodal neurons with visual receptive fields extending into the portion of visual space where the artificial bridge was directed. These results suggest that the fusion of two body parts is represented in terms of cutaneous coordinates in the cortex and external world (visual) coordinates in the superior colliculus. Therefore the differential tactile-tactile and tactile-visual coincident activity seems to be correlated to the different meaning of information processing of these two brain regions.

Suprascapular nerve compression syndrome.

Five patients suffering from suprascapular nerve compression syndrome were treated by surgical decompression of the nerve. The syndrome is described and the surgical treatment is outlined. The diagnostic necessity for electromyography is stressed as is the intraoperative evaluation of the conductive obstacle by use of electrostimulation.