Electromyographic response to manual passive stretch of the hemiplegic wrist: accuracy, reliability, and correlation with clinical spasticity assessment and function.

BACKGROUND: The management of spasticity is important in neurorehabilitation and needs to be assessed accurately. The commonly used clinical tools have been criticized for lack of validity and sensitivity. OBJECTIVE: To investigate the reliability of electromyographic (EMG) response to manual stretches of the hemiplegic wrist and its correlation with clinical assessments of spasticity and physical function. METHODS: EMG activity was measured in 10 stroke patients and control participants (53.7 +/- 10 and 32 +/- 9.1 years respectively, mean +/- SEM) during 3 cycles of 10 seconds passive manual movements of the wrist at 60 to 360 degrees * s(-1). Isometric maximal voluntary contractions (MVC) strength, range of movement (ROM) of the wrist flexors and extensors, spasticity (Modified Ashworth Scale [MAS]) and hand function (Block and Box Test [BBT]) were also assessed. RESULTS: EMG activity of the stroke patients increased with velocity from 4% to 40% MVC (P < .001) but there was none in the controls. It was unaffected by repetition and good to moderate reliability occurred at all speeds (ICC, 0.71-0.81). EMG correlated negatively with MVC strength (r = -.9), active wrist flexion ROM ( r = -.8), and hand function scores (r = -.7), but not with clinical measures of spasticity except at the lowest velocity (r = .72). CONCLUSIONS: Consistent and accurate stretch velocities and EMG responses can be achieved with manual wrist stretches for the assessment of the neural component of spasticity. These objective tests did not correlate well with the standard clinical assessment of spasticity. They showed significant negative relationships with function, indicating that increased reflex excitability contributes to hand disability after stroke.

Long-term intensive electrically stimulated cycling by spinal cord-injured people: effect on muscle properties and their relation to power output.

Inactivity and muscular adaptations following spinal cord injury (SCI) result in secondary complications such as cardiovascular disease, obesity, and pressure sores. Functional electrically stimulated (FES) cycling can potentially reduce these complications, but previous studies have provided inconsistent results. We studied the effect of intensive long-term FES cycle training on muscle properties in 11 SCI subjects (mean +/- SEM: 41.8 +/- 2.3 years) who had trained for up to 1 hour/day, 5 days/week, for 1 year. Comparative measurements were made in 10 able-bodied (AB) subjects. Quadriceps maximal electrically stimulated torque increased fivefold (n = 5), but remained lower than in AB individuals. Relative force response at 1 HZ decreased, relaxation rate remained unchanged, and fatigue resistance improved significantly. Power output (PO) improved to a lesser extent than quadriceps torque and not to a greater extent than has been reported previously. We need to understand the factors that limit PO in order to maximize the benefits of FES cycling.

Cost-effectiveness comparison of tizanidine and baclofen in the management of spasticity.

OBJECTIVE: Baclofen and tizanidine are both used for the treatment of muscle spasticity of spinal origin. Their effectiveness, cost and adverse-effect profiles differ. This paper sets out to estimate the cost effectiveness of each drug, and the impact of changing from baclofen to tizanidine. DESIGN: A simplified but realistic model of physician behaviour and patient response was developed as a decision tree and populated with data derived from the available published clinical comparative trials. We considered patients with spasticity caused by multiple sclerosis or spinal cord injury. The outcome measure used was 'cost per successfully treated day' (STD). Costs were estimated from the perspective of the UK National Health Service at 2000 values. RESULTS: Expected cost for a cohort of 100 patients over 1 year was estimated to be pound 181 545 with baclofen and pound 211 930 with tizanidine. The estimated number of STDs was 20,192 with tizanidine and 17,289 with baclofen. The overall cost effectiveness of managing spasticity using baclofen and tizanidine was very similar ( pound 10.50 and pound 10.49 per STD respectively). The incremental cost effectiveness (ICE) of using tinzanidine as an alternative to baclofen for first-line treatment was pound 10.47 per STD. Sensitivity analysis found the model to be robust to changes in key parameters CONCLUSION: Drug cost should not be a determining factor in making this treatment choice, as the cost effectiveness ratios are similar for both products.

Electrical stimulation in the treatment of pain.

PURPOSE: To review the published literature concerning the treatment of painful conditions using devices that deliver electrical stimulation to nervous structures. The review briefly surveys the results obtained using surface electrodes ("TENS") as well as implanted devices. METHOD: The method used is a critical review of the important published literature up to mid-1999. References were obtained using Medline and the keywords "pain", together with "electrical", "stimulation", "neurostimulation" or "TENS". RESULTS: Electrical stimulation has been found to be of potential benefit in the management of a range of painful conditions. Adequately controlled trials of electrical stimulation are often difficult to achieve. Implanted devices tend to be used in the more severe intractable pain conditions. It is likely that there is more than one mechanism of action. The mechanisms of action are however still often poorly understood, even though historically theoretical and experimental advances in the understanding of pain mechanisms prompted the development of clinical systems and the institution of clinical studies. CONCLUSIONS: TENS has proved to be remarkably safe, and provides significant analgesia in about half of patients experiencing moderate predictable pain. Implanted devices can be more effective, but they carry a risk of device failure, implant infection or surgical complication, and are reserved for the more severe intractable chronic pains. The main implanted devices used clinically are the spinal cord stimulator and the deep brain stimulator.