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

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

A preliminary economic evaluation of percutaneous neuromuscular electrical stimulation in the treatment of hemiplegic shoulder pain

Objective. The objective of this study was to compare the cost-effectiveness of various treatment modalities for hemiplegic shoulder pain. Design. A stage II economic evaluation. Main outcome measures. Incremental cost effectiveness ratio of P-NMES, compared to slings and anti-inflammatory injections. Results. The incremental cost effectiveness ratio (ICER) of p-NMES, compared to anti-inflammatory injections is €6,061 (±3,285). The incremental cost of the first quality-adjusted life year after implantation of the P-NMES device compared to anti-inflammatory injections is €33,007 (±5,434). This decreases to ≈ €7,000 after 5 years, and to ≈ €5,000 after 10 survival years. Conclusion. In this early evaluation, P-NMES seems to be cost-effective according to known guidelines. Treatment with P-NMES is recommended for patients with chronic HSP

Multimodal and widespread somatosensory abnormalities in persistent shoulder pain in the first 6 months efter stroke: An exploratory study

Objective: To explore the role of multimodal and widespread somatosensory abnormalities in the development of persistent poststroke shoulder pain (pPSSP) in the first 6 months after stroke. Design: Prospective inception cohort study. Setting: Stroke units of 2 teaching hospitals. Participants: The data of a strict selection of patients (N=31) with a clinical diagnosis of stroke were analyzed. Interventions: Not applicable. Main Outcome Measures: The development of pPSSP within the first 6 months after stroke. Bilateral sensation and pain thresholds at 3 (t1) and 6 (t2) months, and conditioned pain modulation (CPM) at 3 months after stroke. Clinical examination within 2 weeks after stroke (t0), at t1, and at t2. Results: pPSSP (n=9) was associated with increased sensation and pain threshold ratios at the affected side (t1, t2), and with reduced cold pain tolerance at the unaffected side (t1). CPM was not different from patients without pPSSP (n=22). Notably, in patients with pPSSP reporting increased sensation on clinical examination, multiple body sites across multiple stimulus modalities were involved, and increased sensation persisted from t1 to t2. Conclusions: pPSSP in the first 6 months after stroke was associated with somatosensory loss to both innocuous and noxious stimuli (affected side). In addition, pPSSP was associated with sensitization to cold pain (unaffected side) and with widespread sensitization to multimodal innocuous stimuli (affected side). The results support the notion that central somatosensory sensitization could play an important role in the development of pPSSP, the maintenance of pPSSP, or bot

Somatosensory symptoms and signs and conditioned pain modulation in chronic post-stroke shoulder pain

Persistent shoulder pain is a common complication after stroke. Its etiology and underlying mechanisms are not well understood and treatment is generally unsatisfactory. The objective of this study was to assess the role of central sensitization and disinhibition in chronic stroke patients with chronic PSSP (n = 19), pain-free stroke patients (n = 29), and healthy controls (n = 23). Positive and negative somatosensory symptoms and signs were assessed using clinical examination and electrical and mechanical quantitative sensory testing (QST). Conditioned pain modulation (CPM) was assessed by comparing QST thresholds before and after applying a cold pressor test. Sensory abnormalities were more frequently observed and more severe in patients with PSSP, including positive signs such as allodynia at the affected side and generalized hyperalgesia at the unaffected side. CPM was similar in stroke patients and healthy controls. This study showed that chronic PSSP was associated with several positive and negative somatosensory signs, implicating a role for central sensitization and possibly for disinhibition. Since the causal relationship remains unclear, and may be related to either neuroplasticity induced by ongoing nociception as well as to the neuropathic brain lesion, prospective studies are warranted