Percutaneous neuromuscular electrical stimulation (P-NMES) for treating shoulder pain in chronic hemiplegia. Effects on shoulder pain and quality of life

Objective: To evaluate the effect of percutaneous neuromuscular electrical stimulation (P-NMES) of the shoulder muscles on shoulder pain intensity and health-related quality of life in chronic hemiplegia. Design: Prospective, open label design. Setting: The outpatient services of a large teaching rehabilitation hospital in the Netherlands. Subjects: Fifteen stroke survivors with chronic (> six months) hemiplegia and a therapy-resistant painful shoulder with subluxation. All patients suffered from clinically relevant shoulder pain, as assessed by a score of at least 4 out of 10 on a numerical rating scale. Shoulder subluxation was indicated by at least 1/2 fingerbreadth of glenohumeral separation on palpation. Intervention: Six hours of P-NMES per day for a total of six weeks. Main outcome measures: Shoulder pain (Brief Pain Inventory), shoulder subluxation (clinical and radiographic), shoulder pain-free external rotation (hand-held goniometer), motor impairment (Fugl-Meyer Motor test) and quality of life (SF-36) were assessed before treatment, after six weeks of intramuscular stimulation, at three months and six months follow-up. Results: A significant reduction in pain was found on the Brief Pain Inventory. Pain reduction was still present at six months follow-up. All domains, in particular bodily pain, of the SF-36 showed improvement in the short term. After six months of follow-up, bodily pain was still strongly and significantly reduced, whereas social functioning and role physical demonstrated a nonsignificant improvement of more than 10% compared with baseline. Conclusion: This pilot suggests that P-NMES potentially reduces shoulder pain in chronic hemiplegia. To establish the clinical value of P-NMES in treating hemiplegic shoulder pain a randomized controlled trial is neede

Neuromuscular stimulation after stroke: from technology to clinical deployment\ud

Since the early 1960s, electrical or neuromuscular electrical stimulation (NMES) has been used to support the rehabilitation of stroke patients. One of the earliest applications of NMES included the use of external muscle stimulation to correct drop-foot after stroke. During the last few decades various clinical applications have been used for the upper and lower limb. Despite a growing body of literature on the use of NMES, its application in stroke is still limited to a few clinical groups that provide dedicated clinical services. Some explanations for the limited use are the sometimes conflicting clinical evidence, the size of the effects or the complicated use of the technology itself. This review points out three directions for future research. First, we need to expand our knowledge on brain plasticity and the use of different electrical stimulation strategies to modulate the neural system. Second, we foresee an increase in therapies combining different training principles, for example, the combination of NMES and robotics or neuromodulating drugs. Finally, with the ever-increasing pressure on healthcare budgets, it is expected that clinical and economic evidence will become more relevant in transferring these interventions to a wider communit

Prediction of walking speed using single stance force or pressure measurements in healthy subjects

Walking speed is one of the best measures of overall walking capacity. In plantar pressure measurements, walking speed can be assessed using contact time, but it is only moderately correlated with walking speed. The center of pressure might be of more value to indicate walking speed since walking speed alters foot loading. Therefore, the purpose of this study is to assess walking speed using the velocity of the center of pressure (VCOP). Thirty-three subjects walked over a Footscan pressure plate at three speed conditions; slow, preferred, and fast. Walking speed was measured by a motion analysis system. (Multiple) linear regression analysis was used to indicate the relation between walking speed and independent variables derived from the pressure plate such as mean VCOP and stance time for all walking conditions separately and together. The mean VCOP had the highest correlation coefficient value with walking speed for all walking conditions combined (0.94) and for the preferred walking condition (0.80). The multiple regression analysis, based on a number of additional parameters, revealed a small to modest increase in the performance of predicting walking speed (r=0.98 for combined and r=0.93 for preferred). The mean VCOP was the best predictor for walking speed when using a plantar pressure plate. The mean VCOP predicts the walking speed with a 95% accuracy of 0.20m/s when healthy subjects walk at their preferred walking speed

Prediction of walking speed using single stance force or pressure measurements in healthy subjects.

Walking speed is one of the best measures of overall walking capacity. In plantar pressure measurements, walking speed can be assessed using contact time, but it is only moderately correlated with walking speed. The center of pressure might be of more value to indicate walking speed since walking speed alters foot loading. Therefore, the purpose of this study is to assess walking speed using the velocity of the center of pressure (VCOP). Thirty-three subjects walked over a Footscan pressure plate at three speed conditions; slow, preferred, and fast. Walking speed was measured by a motion analysis system. (Multiple) linear regression analysis was used to indicate the relation between walking speed and independent variables derived from the pressure plate such as mean VCOP and stance time for all walking conditions separately and together. The mean VCOP had the highest correlation coefficient value with walking speed for all walking conditions combined (0.94) and for the preferred walking condition (0.80). The multiple regression analysis, based on a number of additional parameters, revealed a small to modest increase in the performance of predicting walking speed (r=0.98 for combined and r=0.93 for preferred). The mean VCOP was the best predictor for walking speed when using a plantar pressure plate. The mean VCOP predicts the walking speed with a 95% accuracy of 0.20m/s when healthy subjects walk at their preferred walking speed

Classifying post-stroke shoulder pain: can the DN4 be helpful?

The etiology of post-stroke shoulder pain (PSSP) is largely unclear and may involve both nociceptive and neuropathic mechanisms. No gold standard is present for PSSP diagnosis. The neuropathic pain diagnostic questionnaire (DN4), was originally developed to identify neuropathic pain in the clinical context. In this study we used the DN4 to categorize PSSP patients and compared symptoms and signs suggestive of either nociceptive or neuropathic pain. Pain complaints and sensory functions were compared between patients with chronic PSSP scoring at least four (DN4+, n = 9) or less than four (DN4-, n = 10) on the DN4. Pain was assessed using a numeric rating scale and the McGill pain questionnaire. Sensory functions were assessed using clinical examination and quantitative sensory testing combined with a cold pressor test. Patients classified as DN4+ reported constant pain, higher pain intensity, a higher impact of pain on daily living, more frequent loss of cold sensation, reduced QST thresholds at the unaffected side and increased QST thresholds at the affected side. Notably, several symptoms and signs suggestive of either neuropathic or nociceptive pain corresponded to the subgroups DN4+ and DN4- respectively. However, since the pathophysiological mechanisms remain unclear and none of the sensory signs could be exclusively related to either DN4+ or DN4-, PSSP prognosis and treatment should not be solely based on the DN4. Nonetheless, a thorough assessment of neuropathic and nociceptive pain complaints and somatosensory functions should be included in the diagnostic work-up of PSSP

Altered cortical somatosensory processing in chronic stroke: a relationship with post-stroke shoulder pain.

Post-stroke shoulder pain (PSSP), traditionally regarded as purely nociceptive pain, is often persistent and the mechanisms underlying the pain complaints are not well understood. This explorative study is the first to address the possible changes in cortical somatosensory processing in patients with PSSP. Cortical potentials were recorded following intracutaneous electrostimulaton in stroke patients with chronic PSSP (n= 6), pain-free stroke patients (PF, n=14) and healthy controls (HC, n=20) using EEG. Amplitudes and latencies of both sensory discriminative (N90) as well as cognitive evaluative (N150, P200, the N150-P200 peak-to-peak difference and P300) evoked potential components were evaluated. Stroke was associated with reduced N150 and P300 amplitudes and increased N90, N150 and P300 latencies at both sides. Compared to PF and HC, the P200 and N150-P200 latencies were increased in PSSP patients after stimulation at both sides, even when comparing subgroups with similar lesion size and location. Stroke was associated with reduced sensory-discriminative as well as with reduced cognitive-evaluative cortical somatosensory processing. This reduction was more pronounced in patients with PSSP and may be related to the central effects of persistent nociceptive pain