Sensory stimulation augments the effects of massed practice training in persons with tetraplegia

Beekhuizen KS, Field-Fote EC. Sensory stimulation augments the effects of massed practice training in persons with tetraplegia.

Objective

To compare functional changes and cortical neuroplasticity associated with hand and upper extremity use after massed (repetitive task-oriented practice) training, somatosensory stimulation, massed practice training combined with somatosensory stimulation, or no intervention, in persons with chronic incomplete tetraplegia.

Design

Participants were randomly assigned to 1 of 4 groups: massed practice training combined with somatosensory peripheral nerve stimulation (MP+SS), somatosensory peripheral nerve stimulation only (SS), massed practice training only (MP), and no intervention (control).

Setting

University medical school setting.

Participants

Twenty-four subjects with chronic incomplete tetraplegia.

Interventions

Intervention sessions were 2 hours per session, 5 days a week for 3 weeks. Massed practice training consisted of repetitive practice of functional tasks requiring skilled hand and upper-extremity use. Somatosensory stimulation consisted of median nerve stimulation with intensity set below motor threshold.

Main Outcome Measures

Pre- and post-testing assessed changes in functional hand use (Jebsen-Taylor Hand Function Test), functional upper-extremity use (Wolf Motor Function Test), pinch grip strength (key pinch force), sensory function (monofilament testing), and changes in cortical excitation (motor evoked potential threshold).

Results

The 3 groups showed significant improvements in hand function after training. The MP+SS and SS groups had significant improvements in upper-extremity function and pinch strength compared with the control group, but only the MP+SS group had a significant change in sensory scores compared with the control group. The MP+SS and MP groups had greater change in threshold measures of cortical excitability.

Conclusions

People with chronic incomplete tetraplegia obtain functional benefits from massed practice of task-oriented skills. Somatosensory stimulation appears to be a valuable adjunct to training programs designed to improve hand and upper-extremity function in these subjects.     

Implanted Electrical Stimulation of the Trunk for Seated Postural Stability and Function After Cervical Spinal Cord Injury: A Single Case Study

Triolo RJ, Boggs L, Miller ME, Nemunaitis G, Nagy J, Bailey SN. Implanted electrical stimulation of the trunk for seated postural stability and function after cervical spinal cord injury: a single case study.

Objectives

To explore and quantify the physical and functional effects of stabilizing the torso with electrical stimulation of the paralyzed hip and trunk musculature after motor complete tetraplegia.

Design

Single-subject case study with repeated measures and concurrent controls.

Setting

Academic outpatient rehabilitation center.

Participants

Forty-four-year-old man with C4 American Spinal Injury Association grade A tetraplegia 20 years postspinal cord injury.

Intervention

A surgically implanted multichannel pulse generator and intramuscular stimulating electrodes to activate lumbar erector spinae, quadratus lumborum, and gluteus maximus muscles bilaterally.

Main Outcome Measures

Outcomes assessed with and without stimulation included (1) spinal alignment and pelvic orientation, (2) pulmonary function and ventilatory volumes, (3) forward bimanual reaching distance, (4) seated stability and resistance to externally applied disturbances, (5) maximal force and speed of rowing-like movements, and the ability to (6) independently return to an erect seated position from full forward or lateral flexion and (7) roll in bed without assistance.

Results

Stimulation improved spinal convexity and kyphosis by 26° and 21°, reduced posterior pelvic tilt by 11°, increased forced expiratory volume and vital capacity by 10% and 22%, and improved forward reach by more than 7cm. Average resistance to sagittal disturbances increased by more than 40% (P<.002), and mean force exerted during underhanded pulling more than doubled (P=.014) with stimulation. Restoration of upright sitting in both sagittal and coronal planes and bed turning was made possible through appropriately timed activation of the hip and trunk muscles.

Conclusions

A neuroprosthesis for controlling the paralyzed torso can positively impact spinal alignment, seated posture, pulmonary function, trunk stability, and reach. Stimulation of hip and trunk muscles can improve performance of activities of daily living as well as enable independent wheelchair and bed mobility.     

Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats

DeSantana JM, Santana-Filho VJ, Sluka KA. Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats.

Objective

To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance.

Design

Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%-2%).

Setting

Laboratory.

Animals

Adult male Sprague-Dawley rats (N=36).

Intervention

Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100μs pulse duration.

Main Outcome Measures

Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS.

Results

The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds.

Conclusions

These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop.     

Electric Pulse Frequency and Magnitude of Perceived Sensation During Electrocutaneous Forearm Stimulation

Jelinek HF, McIntyre R. Electric pulse frequency and magnitude of perceived sensation during electrocutaneous forearm stimulation.

Objectives

To investigate the effect that electric pulse frequency has on the perceived magnitude of sensation and to quantify the relationship between electric pulse frequency and perceived magnitude of sensation during low-intensity electrocutaneous stimulation.

Design

A repeated-measures research design was applied to evaluate the effect of electric pulse frequency on the perceived magnitude of electrocutaneous stimulation.

Setting

Electrocutaneous agents laboratory.

Participants

University students (N=26) with normal hearing and normal sensation were recruited for the study.

Interventions

Electrocutaneous stimulation was applied to the forearm at 10 electric pulse frequencies.

Main Outcome Measures

A cross-modality matching procedure was used in which stimulation intensity was matched with the level of loudness. Pairwise comparisons with 2 degrees of freedom at a power of 80% was performed. Statistical significance was set at P equal to .05.

Results

Electric pulse frequency had a significant effect on the perceived magnitude of sensation, with the perceived sensation growing between 0 and 120Hz (F=36.02; P<.001). The relationship between the 2 variables was strong (r²=.99; P<.01).

Conclusions

Increasing the electric pulse frequency of electrocutaneous stimulation increases the perceived magnitude of the resulting sensation. This has implications for the use of electrocutaneous stimulation for both analgesia and muscle stimulation.     

The vastus medialis oblique:vastus lateralis electromyographic intensity ratio does not differ by gender in young participants without knee pathology

Objectives

To investigate whether there was a gender difference in the intensity of electromyographic (EMG) activity in vastus medialis oblique (VMO) relative to vastus lateralis (VL).

Design

A cross-sectional observational study measuring EMG activity during stepping down from a step and during straight leg raise exercises.

Setting

University campus laboratory.

Participants

Two groups of healthy participants were tested, one female (mean age 23.5 years, n = 15) and one male (mean age 23.5 years, n = 15).

Main outcome measures

Surface EMG activity (sampling rate 1000 Hz) was recorded from VMO and VL of the dominant limb during five repetitions of a step down activity and five repetitions of a straight leg raise exercise. The average intensity of the rectified and smoothed EMG activity from each activity was normalised to that elicited in a maximal quadriceps setting exercise. The ratio of normalised VMO:VL EMG intensity levels was calculated.

Results

The median difference in the VMO:VL ratio between the groups was 0.11 [approximate 95% confidence interval (CI) −0.62 to 1.00] during step down and −0.07 (approximate 95% CI −0.26 to 0.20) during straight leg raise. Using Mann Whitney U-tests, these differences were not statistically significant (P = 0.648 and 0.619, respectively).

Conclusions

This study found no gender difference in the VMO:VL EMG intensity ratio in asymptomatic participants. This suggests that the difference in incidence of patellofemoral pain syndrome between genders is not influenced by quadriceps intensity ratios, when participants are asymptomatic.     

The interaction between executive attention and postural control in dual-task conditions: children with cerebral palsy

Reilly DS, Woollacott MH, van Donkelaar P, Saavedra S. The interaction between executive attention and postural control in dual-task conditions: children with cerebral palsy.

Objective

To investigate the interference between a secondary task and a postural task in children with cerebral palsy (CP).

Design

In this exploratory study, a dual-task paradigm was used in which children stood in either a wide or a narrow stance position while simultaneously performing a visual working memory task calibrated to be of equitable attentional demand between groups.

Setting

Study data were gathered in a university motor control laboratory.

Participants

Children with CP (n=8; age range, 10−14y) were compared with typically developing older children (n=6; age range, 7−12y), and typically developing young children (n=5; age range, 4−6y).

Interventions

Not applicable.

Main Outcome Measures

Proficiency in postural control was measured by the range and root mean square of the velocity of center of pressure displacement in the mediolateral and anteroposterior directions, calculated from forceplate data. Accuracy of response was used as a measure of cognitive task performance. Capacity of the executive attention system was determined by assessing visual working memory capacity.

Results

Children with CP, like the typically developing young children, were more unstable and had less executive attention capacity compared with older children, and like the typically developing young children, experienced dual-task interference in postural control in both stance positions. Children with ataxic CP also experienced decreased cognitive task performance in narrow stance.

Conclusions

In designing therapeutic interventions for children with CP, it would be beneficial for clinicians to assess postural control in both single- and dual-task environments.     

Somatosensory stimulation enhances the effects of training functional hand tasks in patients with chronic stroke

Celnik P, Hummel F, Harris-Love M, Wolk R, Cohen LG. Somatosensory stimulation enhances the effects of training functional hand tasks in patients with chronic stroke.

Objective

To test the hypothesis that somatosensory stimulation would enhance the effects of training functional hand tasks immediately after practice and 1 day later in chronic subcortical stroke patients.

Design

Single-blinded and randomized, crossover study.

Setting

Human research laboratory.

Participants

Nine chronic subcortical stroke patients.

Interventions

Three separate sessions of motor training preceded by (1) synchronous peripheral nerve stimulation (PNS), (2) no stimulation, or (3) asynchronous PNS.

Main Outcome Measures

Time to complete the Jebsen-Taylor Hand Function Test (JTHFT time) and corticomotor excitability tested with transcranial magnetic stimulation.

Results

After familiarization practice, during which all patients reached a performance plateau, training under the effects of PNS reduced JTHFT time by 10% beyond the post-familiarization plateau. This behavioral gain was accompanied by a specific reduction in GABAergically mediated intracortical inhibition in the motor cortex. These findings were not observed after similar practice under the influence of no stimulation or asynchronous PNS sessions.

Conclusions

Somatosensory stimulation may enhance the training of functional hand tasks in patients with chronic stroke, possibly through modulation of intracortical GABAergic pathways.     

Lower Thoracic Spinal Cord Stimulation to Restore Cough in Patients With Spinal Cord Injury: Results of a National Institutes of Health-Sponsored Clinical Trial. Part I: Methodology and Effectiveness of Expiratory Muscle Activation

DiMarco AF, Kowalski KE, Geertman RT, Hromyak DR. Lower thoracic spinal cord stimulation to restore cough in patients with spinal cord injury: results of a National Institutes of Health-sponsored clinical trial. Part I: methodology and effectiveness of expiratory muscle activation.

Objective

Evaluation of the capacity of lower thoracic spinal cord stimulation (SCS) to activate the expiratory muscles and generate large airway pressures and high peak airflows characteristic of cough, in subjects with tetraplegia.

Design

Clinical trial.

Setting

Inpatient hospital setting for electrode insertion; outpatient setting for measurement of respiratory pressures; home setting for application of SCS.

Participants

Subjects (N=9; 8 men, 1 woman) with cervical spinal cord injury and weak cough.

Interventions

A fully implantable electrical stimulation system was surgically placed in each subject. Partial hemilaminectomies were made to place single-disk electrodes in the epidural space at the T9, T11, and L1 spinal levels. A radiofrequency receiver was placed in a subcutaneous pocket over the anterior portion of the chest wall. Electrode wires were tunneled subcutaneously and connected to the receiver. Stimulation was applied by activating a small portable external stimulus controller box powered by a rechargeable battery to each electrode lead alone and in combination.

Main Outcome Measures

Peak airflow and airway pressure generation achieved with SCS.

Results

Supramaximal SCS resulted in high peak airflow rates and large airway pressures during stimulation at each electrode lead. Maximum peak airflow rates and airway pressures were achieved with combined stimulation of any 2 leads. At total lung capacity, mean maximum peak airflow rates and airway pressure generation were 8.6±1.8 (mean ± SE) L/s and 137±30 cmH₂O (mean ± SE), respectively.

Conclusions

Lower thoracic SCS results in near maximum activation of the expiratory muscles and the generation of high peak airflow rates and positive airway pressures in the range of those observed with maximum cough efforts in healthy persons.     

Change of Strength and Rate of Rise of Tension Relate to Functional Arm Recovery After Stroke

Renner CIE, Bungert-Kahl P, Hummelsheim H. Change of strength and rate of rise of tension relate to functional arm recovery after stroke.

Objective

To examine the relationship between individual strength parameters and functional motor ability over time during rehabilitation in stroke patients.

Design

A multiple-baseline experiment with assessment at inclusion and after 3 and 6 weeks.

Setting

Secondary-care rehabilitation center.

Participants

A convenience sample of 16 subacute stroke patients.

Interventions

Not applicable.

Main Outcome Measures

Maximal voluntary force and rate of rise of tension of hand grip, wrist extension, and elbow flexion and extension were recorded at all 3 times. At the same time, functional motor assessments were evaluated by the Action Research Arm Test (ARAT), Box and Block test, and Rivermead Test.

Results

We found no correlation between maximal voluntary force increases of various muscle contractions measurements. Neither the increase of grip strength nor that of wrist extension force correlated with improvement in ARAT score. Yet the improvement in the rate of rise of tension of hand grip (Spearman rho=.91) and of wrist extension (Spearman rho=.73) correlated with the improvement of the ARAT score and explained 77% of the variance of the ARAT.

Conclusions

The change in the rate of rise of tension of the hand grip has a better predictive value for the functional recovery compared to the change in maximal voluntary force in patients with moderate arm and hand weakness after stroke. The rate of rise of tension of hand grip seems an adequate quantifiable parameter to detect small improvements during functional recovery.     

Evaluation of postural control in quiet standing using center of mass acceleration: comparison among the young, the elderly, and people with stroke

Yu E, Abe M, Masani K, Kawashima N, Eto F, Haga N, Nakazawa K. Evaluation of postural control in quiet standing using center of mass acceleration: comparison among the young, the elderly, and people with stroke.

Objective

To determine center of mass (COM) acceleration usefulness in the evaluation of postural control during quiet standing.

Design

Three-group comparison design.

Setting

A research laboratory.

Participants

Poststroke subjects (n=12), healthy elderly subjects (n=22), and healthy young subjects (n=25).

Interventions

Not applicable.

Main Outcome Measures

With a force platform, postural sway was evaluated by using the standard deviations of COM acceleration and center of pressure (COP) and COM (COP-COM) in which COP-COM represents the distance between the COP and the COM.

Results

COM acceleration and COP-COM variables were greater in the poststroke group than in the healthy groups (elderly and young) in the mediolateral (ML) direction. Both variables in the anteroposterior (AP) direction were greater in the poststroke group and the elderly group than in the young group. Furthermore, the correlations between COM acceleration and COP-COM in each group in each direction were shown to be significantly high (r range, .906-.979; P<.001).

Conclusions

COM acceleration was useful in the evaluation of postural control during quiet standing when comparing the young, the elderly, and poststroke patients. Additionally, COM acceleration and COP-COM in both the AP and ML directions during quiet standing were significantly and highly correlated. Thus, we proposed that COM acceleration can be an alternative and convenient measure instead of COP-COM in the evaluation of postural control.     

A Comparison of Functional Electrical and Magnetic Stimulation for Propelled Cycling of Paretic Patients

Szecsi J, Schiller M, Straube A, Gerling D. A comparison of functional electrical and magnetic stimulation for propelled cycling of paretic patients.

Objective

To compare isometric torque and cycling power, smoothness and symmetry using repetitive functional magnetic stimulation (FMS) and functional electrical stimulation (FES) in patients with paretic legs with preserved sensibility and in patients without sensibility.

Design

Repeated-measures design.

Setting

Laboratory setting.

Participants

Eleven subjects with complete spinal cord injury (SCI) and 29 subjects with chronic hemiparesis (16.6±5.5mo poststroke) volunteered.

Interventions

Using a tricycle testbed, participants were exposed to isometric measurements and ergometric cycling experiments, performed during both 20Hz FMS and FES stimulation. Subjects with hemiparesis and with complete SCI were stimulated at maximally tolerable level and maximal intensity, respectively.

Main Outcome Measures

Maximal isometric pedaling torque and mean ergometric power, smoothness, and symmetry were recorded for voluntary, FES, and FMS conditions.

Results

Two different patterns of the efficacy of FMS were identified. (1) Patients with complete SCI did not benefit (less torque and power was evoked with FMS than with FES, P<.003 and 10⁻⁴ respectively). (2) Patients with hemiplegia and preserved sensibility could improve their torque output (P<.05), smoothness, and symmetry of pedaling (P<.05) with FMS more than with FES.

Conclusions

FMS is a potential alternative to surface FES of the large thigh musculature in stimulation-supported cycling of patients with partially or completely preserved sensibility.     

Multiple Sclerosis and Postural Control: The Role of Spasticity

Sosnoff JJ, Shin S, Motl RW. Multiple sclerosis and postural control: the role of spasticity.

Objectives

To examine the association between spasticity and postural control in subjects with multiple sclerosis (MS).

Design

Cross-sectional.

Setting

Motor control laboratory.

Participants

Subjects with MS (n=16, 2 male) and age and sex-matched subjects (n=16) participated in the investigation. All subjects with MS had Expanded Disability Status Scale scores between 0 and 4.5 and modified Ashworth scale scores between 1 and 3.

Interventions

Not applicable.

Main Outcome Measures

Postural control was measured with a force platform that quantifies ground reaction forces and moments in mediolateral and anteroposterior directions. Postural control was indexed with anterior-posterior sway range, medial-lateral sway range, 95% elliptical area of the deviations of center of pressure (COP), velocity of COP sway, and the frequency at which 95% of spectral profile was contained. Participants with MS further underwent assessment of the soleus Hoffman reflex (H-reflex) as an index of spasticity.

Results

Cluster analysis on H-reflex data identified groups of MS participants with high spasticity (n=7) and low spasticity (n=9). There were no differences in age, duration of MS, and disease severity between MS groups. There were no differences in anterior-posterior sway range between any of the groups. The high spasticity group had greater COP area, velocity, and mediolateral sway compared with the low spasticity and control group, and the low spasticity group had postural control values between the high spasticity and control groups.

Conclusions

The pattern of results suggests that spasticity contributes to postural deficits observed in MS.     

The effect of exercise training in improving motor performance and corticomotor excitability in people with early Parkinson's disease

Fisher BE, Wu AD, Salem GJ, Song J, Lin C-H, Yip J, Cen S, Gordon J, Jakowec M, Petzinger G. The effect of exercise training in improving motor performance and corticomotor excitability in people with early Parkinson's disease.

Objectives

To obtain preliminary data on the effects of high-intensity exercise on functional performance in people with Parkinson's disease (PD) relative to exercise at low and no intensity and to determine whether improved performance is accompanied by alterations in corticomotor excitability as measured through transcranial magnetic stimulation (TMS).

Design

Cohort (prospective), randomized controlled trial.

Setting

University-based clinical and research facilities.

Participants

Thirty people with PD, within 3 years of diagnosis with Hoehn and Yahr stage 1 or 2.

Interventions

Subjects were randomized to high-intensity exercise using body weight-supported treadmill training, low-intensity exercise, or a zero-intensity education group. Subjects in the 2 exercise groups completed 24 exercise sessions over 8 weeks. Subjects in the zero-intensity group completed 6 education classes over 8 weeks.

Main Outcome Measures

Unified Parkinson's Disease Rating Scales (UPDRS), biomechanic analysis of self-selected and fast walking and sit-to-stand tasks; corticomotor excitability was assessed with cortical silent period (CSP) durations in response to single-pulse TMS.

Results

A small improvement in total and motor UPDRS was observed in all groups. High-intensity group subjects showed postexercise increases in gait speed, step and stride length, and hip and ankle joint excursion during self-selected and fast gait and improved weight distribution during sit-to-stand tasks. Improvements in gait and sit-to-stand measures were not consistently observed in low- and zero-intensity groups. The high-intensity group showed lengthening in CSP.

Conclusions

The findings suggest the dose-dependent benefits of exercise and that high-intensity exercise can normalize corticomotor excitability in early PD.     

Prevalence and Impact of Pain in Multiple Sclerosis: Physical and Psychologic Contributors

Hirsh AT, Turner AP, Ehde DM, Haselkorn JK. Prevalence and impact of pain in multiple sclerosis: physical and psychologic contributors.

Objective

To characterize the prevalence and impact of pain in veterans with multiple sclerosis (MS) and to assess their association with demographic, biologic, and psychologic variables.

Design

Cross-sectional cohort study linking computerized medical record information to mailed survey data.

Setting

Veterans Health Administration (VHA).

Participants

Sixty-four percent (2994/4685) of veterans with MS who received services in VHA and also returned survey questionnaires.

Interventions

Not applicable.

Main Outcome Measures

Items assessing pain intensity, pain interference, and physical and mental health functioning.

Results

Ninety-two percent of participants reported bodily pain within the prior 4 weeks, with 69% of the total sample indicating pain of moderate or higher intensity. Eighty-five percent indicated that pain caused functional interference during the past 4 weeks, with 71% of the total sample reporting pain-related interference that was moderate or greater. No significant sex or race differences emerged for the pain indices. A significant but modest relationship between increasing age and pain interference emerged (r=.05, P<.01); however, age was not significantly related to pain intensity. Multivariate regression analyses identified pain intensity (β=.73), physical health functioning (β=-.07), and mental health functioning (β=-.13) variables as significant, unique contributors to the prediction of pain interference. The interaction of pain intensity and physical functioning was also significant but of minimal effect size (β=-.03).

Conclusions

Pain is highly prevalent and causes substantial interference in the lives of veterans with MS. The functional impact of pain in veterans with MS is influenced by pain intensity, physical health, and emotional functioning. Clinical practice should take each of these domains into consideration and reflect a biopsychosocial conceptualization.     

Lowering of Sensory, Motor, and Pain-Tolerance Thresholds With Burst Duration Using Kilohertz-Frequency Alternating Current Electric Stimulation: Part II

Ward AR, Lee Hung Chuen WL. Lowering of sensory, motor, and pain-tolerance thresholds with burst duration using kilohertz-frequency alternating current electric stimulation: part II.

Objective

To determine the optimum burst duration for discrimination between sensory, motor, and pain tolerance thresholds using 20-Hz bursts of kilohertz-frequency sinusoidal alternating current (AC) applied transcutaneously to human participants.

Design

A within-subject, repeated-measures trial.

Setting

A research laboratory.

Participants

Healthy young adults (N=20).

Interventions

Bursts of AC electric stimulation at frequencies of 1 and 4kHz. The burst frequency was 20Hz. Burst durations ranged from 250 microseconds (for 1 cycle of 4-kHz AC) and 1 millisecond (for 1 cycle of 1-kHz AC) to 50 milliseconds (continuous AC).

Main Outcome Measures

Measurement of sensory, motor, and pain-tolerance thresholds.

Results

Thresholds decreased to a minimum with increasing burst duration. The minimum threshold identified the utilization time over which summation of subthreshold stimuli occurs. Utilization times were different for sensory (∼20ms), motor (∼30ms), and pain (>50ms) and were much higher than found in a previous study that used a higher burst frequency (50Hz). As with the previous study, relative thresholds were found to vary with burst duration. Despite the very different utilization times, maximum separation between sensory, motor, and pain thresholds was found to occur with bursts in the range of 1 to 4 milliseconds, the same range found in the previous study.

Conclusions

Our conclusions concur with those reported previously and support the contention that short-duration kilohertz-frequency AC bursts (1-4ms) have a more useful role in rehabilitation than the long-duration kilohertz-frequency bursts that characterize Russian and interferential currents.     

What are the costs to NHS Scotland of self-referral to physiotherapy? Results of a national trial

Background

Recent healthcare policies have encouraged increasing interest in the concept of patient self-referral, specifically with regard to physiotherapy. However, what has not been known until recently is the efficacy of this mode of access within the National Health Service (NHS), including the cost implications on which to reliably base the provision of future service models.

Aim

To establish the costs to National Health Service (NHS) Scotland of differing modes of access to physiotherapy in primary care.

Design

Cost-minimisation analysis, multi-centred national trial.

Setting

Twenty-six general practices throughout Scotland.

Participants

Three-thousand and ten patients.

Method

Self-referral was introduced in each site in parallel with referral by a general practitioner (GP). NHS-associated cost data were collated over a full year by referral type, i.e. self-referral, GP-suggested and GP-referral groups. A cost-minimisation analysis was performed and the main outcome measures were the number of GP and physiotherapy contacts, prescribing of non-steroidal anti-inflammatory drugs and analgesics, and referral for X-ray, magnetic resonance imaging and/or secondary care. Costs were established for 2004.

Results

The data from 3010 patients identified significant associations between referral group and prescribing, referral for X-ray and to secondary care, and GP and physiotherapy contacts (P < 0.001). The average cost of an episode of care was established as £66.31 for a self-referral, £79.50 for a GP-suggested referral and £88.99 for a GP referral. Extrapolated to identify national implications, the average cost benefit to NHS Scotland was identified as being approximately £2 million per annum.

Conclusion

There are significant positive implications associated with self-referral to physiotherapy that represent added value for NHS Scotland. These implications are also of relevance to the rest of the NHS in the UK.     

Association between PON1 5′-regulatory region polymorphisms, PON1 activity and ischemic stroke

Objectives

Paraoxonase I (PON1) was known as a risk factor for cerebrovascular diseases. This study assessed the association of single nucleotide polymorphisms (SNPs) in the PON1 5′-regulatory region with ischemic stroke and serum PON1 activity.

Design and methods

Study subjects consisted of 418 healthy controls and 86 ischemic stroke patients with small vessel occlusion. SNPs were identified by DNA sequencing and a primer extension-based method.

Results

Among 10 identified SNPs, only −1434GG genotype was observed with a lower frequency in patients on borderline statistical significance (OR(95% CI), 0.297(0.083-1.060), p = 0.0615). However, haplotype analysis in a dominant model revealed that ht2 was observed with a significantly lower frequency in patients (OR(95% CI), 0.390(0.153-0.991), p = 0.0477). Both C(−1434)G mutation and ht2 distribution were associated with serum PON1 activity.

Conclusion

Our results suggest that haplotypes observed in the PON1 5′-regulatory region should be considered as risk factors for ischemic stroke.     

Differential Performance of SF-36 Items in Healthy Adults With and Without Functional Limitations

Horner-Johnson W, Krahn GL, Suzuki R, Peterson JJ, Roid G, Hall T, the RRTC Expert Panel on Health Measurement. Differential performance of SF-36 items in healthy adults with and without functional limitations.

Objective

To determine whether Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) items show differential item functioning among healthy adults with various types of functional limitations as compared with a healthy sample with no identified limitations.

Design

Survey responses were analyzed by using partial correlations.

Setting

General community.

Participants

Participants (N=206) included (1) adults with spinal cord injury (SCI), (2) adults who were deaf or hard of hearing, (3) adults who were legally blind, (4) adults with psychiatric or emotional conditions, and (5) adults with no reported functional limitations. Participants were screened to ensure the absence of substantial health problems.

Interventions

Not applicable.

Main Outcome Measure

SF-36.

Results

Partial correlations showed a significant negative correlation, indicating differential item functioning (ie, apparent bias) for people with SCI on all 10 SF-36 Physical Functioning items. For people who were blind, 5 items showed a significant negative correlation. Two items had significant negative correlations for the deaf/hard-of-hearing group. One item showed significant negative performance for people with mental health conditions.

Conclusions

Our data indicated a possibility for measurement bias caused by the blending of health and function concepts in the SF-36.     

Neutral functional realignment orthosis prevents hand pain in patients with subacute stroke: a randomized trial

Bürge E, Kupper D, Finckh A, Ryerson S, Schnider A, Leemann B. Neutral functional realignment orthosis prevents hand pain in patients with subacute stroke: a randomized trial.

Objective

To quantify the preventive effect of a neutral functional realignment orthosis on pain, mobility, and edema of the hand in subacute hemiparetic poststroke patients with severe motor deficits.

Design

Randomized trial.

Setting

Rehabilitation center.

Participants

Poststroke patients (N=30) with subacute hemiparesis and severe deficits of the upper limb were enrolled. Fifteen patients were randomized to a standard rehabilitation program without orthosis and 15 patients received an experimental orthosis in addition to their standard rehabilitation program.

Intervention

The orthosis group wore the neutral functional realignment orthosis for at least 6 hours daily.

Main Outcome Measures

Hand pain at rest (visual analog scale), wrist range of motion (Fugl-Meyer Assessment subscale), and edema of hand and wrist (circumferences). Outcome measures were assessed at time of randomization and after 13 weeks between groups.

Results

At baseline, 2 patients in each group complained about a painful hand. After 13 weeks, 8 subjects in the control group and 1 subject in the orthosis group complained of hand pain (P=.004). Mobility and edema evolved similarly in both groups.

Conclusions

Neutral functional realignment orthoses have a preventive effect on poststroke hand pain, but not on mobility and edema in the subacute phase of recovery.     

Estimating contraction level using root mean square amplitude in control subjects and patients with neuromuscular disorders

Boe SG, Rice CL, Doherty TJ. Estimating contraction level using root mean square amplitude in control subjects and patients with neuromuscular disorders.

Objectives

To assess the utility of the surface electromyographic signal as a means of estimating the level of muscle force during quantitative electromyography studies by examining the relationship between muscle force and the amplitude of the surface electromyographic activity signal; and to determine the impact of a reduction in the number of motor units on this relationship, through inclusion of a sample of patients with neuromuscular disease.

Design

Cross-sectional, cohort study design.

Setting

Tertiary care, ambulatory, electromyography laboratory.

Participants

A volunteer, convenience sample of healthy control subjects (n=10), patients with amyotrophic lateral sclerosis (n=9), and patients with Charcot-Marie-Tooth disease type X (n=5).

Interventions

Not applicable.

Main Outcome Measures

The first dorsal interosseous (FDI) and biceps brachii muscles were examined. Force values (at 10% increments) were calculated from two 4-second maximal voluntary contractions (MVCs). Surface electromyographic activity was recorded during separate 4-second voluntary contractions at 9 force increments (10% -90% of MVC). Additionally, a motor unit number estimate was derived for each subject to quantify the degree of motor unit loss in patients relative to control subjects.

Results

The relationships between force and surface electromyographic activity for both muscles (controls and patients) were best fit by a linear function. The variability about the grouped regression lines was quantified by 95% confidence intervals and found to be ±6.7% (controls) and ±8.5% (patients) for the FDI and ±5% (controls) and ±6.1% (patients) for the biceps brachii.

Conclusions

These results suggest that the amplitude of the surface electromyographic activity signal may be used as a means of estimating the level of muscle force during quantitative electromyography studies. Future studies should be directed at examining if the variability associated with these force and surface electromyographic activity relationships is acceptable in replacing previous methods of measuring muscle force.