Spasticity in spinal cord injured patients: 2. Initial measures and long-term effects of surface electrical stimulation

Electrical stimulation of paralyzed muscles has been shown to affect their spasticity, especially in patients with hemiplegia. But little has been reported on the long-term effects of such stimulation on individuals with spinal cord injury. This paper documents initial quadriceps spasticity in 31 spinal cord injured subjects, and the effect of four to eight weeks of reconditioning using electrical stimulation. Spasticity was quantified through the use of a normalized relaxation index (R2n) obtained from a pendulum drop test. The reconditioning protocol consisted of twice daily 20-minute exercise sessions at least four hours apart, six days per week. Spasticity and stimulated quadriceps torque were measured during one to three evaluations performed at least one day apart at the beginning of the program, and at four and eight weeks. There was no significant difference in average initial measures of spasticity between left and right legs and no effect of time since injury on average R2n values. Significant differences were seen for right leg average baseline R2n values when grouped by lesion level or completeness. Quadriplegic individuals were more spastic than paraplegic individuals, and subjects with incomplete lesions were more spastic than those with complete lesions. These findings are interrelated since most of the quadriplegic subjects (14 of 16) had incomplete lesions. Most participants had increased spasticity after four weeks of reconditioning but not after eight weeks. However, only eight subjects completed eight weeks of reconditioning. Subjects who had the greatest increases in spasticity also had the greatest gains in stimulated torque, both after four and eight weeks.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electrical stimulation in treating spasticity resulting from spinal cord injury

To study the efficacy of electrical stimulation in treating spasticity of six spinal cord injured patients, transcutaneous electrical nerve stimulation (TENS) was applied to the dermatomes belonging to the same spinal cord level as the selected spastic muscle group. Spasticity was assessed in knee extensors by a pendulum test in which the knee joint angle of a swinging lower leg was recorded with an electrogoniometer. TENS was found to produce a noticeable decrease of spasticity in three of the patients, but had little effect on the others.     

Effects of thoraco-lumbar electric sensory stimulation on knee extensor spasticity of persons who survived cerebrovascular accident (CVA)

Spasticity is mostly due to an excess of impulses to alpha motor neurons partly resulting from a change of interneuron activity. Low threshold afferent has been reported to change the activity in interneuron. The purpose of this study is to investigate the effects of surface spinal paravertebral stimulation on knee extensor spasticity. Ten survivors of stroke, with knee extensor spasticity, received electric stimulation for five 45-minute periods through surface electrodes applied to the skin in the twelfth thoracic and first lumbar areas. The electric stimulations had an amplitude modulated alternating current (AC), with a carrier frequency of 2500 Hz, modulated to "beats" frequency of 20 Hz. Stimulation amplitude was raised to elicit sensory stimulation. The pre- and post-treatment evaluation included the modified Ashworth scale, active torque during controlled knee movements at various velocities, and electromyographic (EMG) activity during the torque measurements. Our results indicate that nine of ten subjects demonstrated a decrease in the modified Ashworth scale post-treatment. The EMG activity of the spastic quadriceps during active knee flexion was decreased post-treatment as compared with the value before treatment. The active torque value of knee flexion or extension at 30 degrees, 60 degrees, or 90 degrees/sec of angular velocity did not change significantly post-treatment. A trend of increasing spastic quadriceps EMG activity with respect to the angular velocity during an active knee flexion was established, with Ashworth scale considered. The level of EMG activity is higher when the Ashworth scale is higher. According to our results, the surface paravertebral sensory stimulation was effective in reducing quadriceps muscle spasticity of the subjects. Both the modified Ashworth scale and the EMG activity of spastic quadriceps during eccentric contraction are suggested as sensitive tools for measuring spasticity of persons who survived cerebrovascular accident (CVA).     

Evaluation of pendulum testing of spasticity]

OBJECTIVES: To identify valid measurements of spasticity derived from the pendulum test of the leg in a representative population of spastic patients. MATERIAL AND METHODS: Pendulum testing was performed in 15 spastic and 10 matched healthy subjects. The reflex-mediated torque evoked in quadriceps femoris, as well as muscle mechanical parameters (viscosity and elasticity), were calculated using mathematical modelling. Correlation with the two main measures derived from the pendulum test reported in the literature (the Relaxation Index and the area under the curve) was calculated in order to select the most valid. RESULTS, DISCUSSION: Among mechanical parameters, only viscosity was found to be significantly higher in the spastic group. As expected, the computed integral of the reflex-mediated torque was found to be larger in spastics than in healthy subjects. A significant non-linear (logarithmic) correlation was found between the clinically-assessed muscle spasticity (Ashworth grading) and the computed reflex-mediated torque, emphasising the non-linear behaviour of this scale. Among measurements derived from the pendulum test which are proposed in the literature for routine estimation of spasticity, the Relaxation Index exhibited an unsuitable U-shaped pattern of variation with increasing reflex-mediated torque. On the opposite, the area under the curve revealed a linear regression, which is more convenient for routine estimation of spasticity. CONCLUSION: The pendulum test of the leg is a simple technique for the assessment of spastic hypertonia. However, the measurement generally used in the literature (the Relaxation Index) exhibits serious limitations, and would benefit to be replaced by more valid measures, such as the area under the goniometric curve, especially for the assessment of therapeutics.     

等速运动测试仪量化评定痉挛的研究

痉挛是上运动神经元损伤性疾患的常见症状。正确评定和处理痉挛有重要的临床意义。但是由于痉挛是肌肉在病理状态下的一种神经生理表现,不易直接测量,尤其是量化评定的问题成为康复医学研究中的一个难题,越来越受到人们的关注。本研究目的：寻找一种痉挛量化评定的新方法。方法：利用等速运动测试仪CybexⅡ结合评定痉挛常用的摆动试验进行痉挛的量化评定研究。本研究对观察组34例痉挛患者,对照1组9例驰缓性麻痹患者,对照2组10例正常人下肢肌张力进行了评定。结果：记录到了各种不同的摆动曲线,并找到5个有代表性的特征性参数：A₁（第一摆膝关节屈曲角度）、R₁、（放松指数）、R₂、（幅度比）、T（摆动时间）、F（摆动次数）。经统计学检验观察组与对照组间有显著差异。实验结果信度、效度很高。结论：本方法可以做痉挛量化评定的指标。     

Antispastic effect of penile vibration in men with spinal cord lesion

OBJECTIVE: To evaluate the possible antispastic effect of penile vibratory stimulation (PVS) in men with spinal cord lesion (SCL). DESIGN: Unblinded, before-after trial. SETTING: Ambulatory care. PARTICIPANTS: Nine men with SCLs from C2 to T8 were randomly allocated into 2 groups. INTERVENTION: Twenty-four hours of electromyographic recordings from the quadriceps and tibialis anterior muscles were taken, followed by PVS or no treatment and another 24 hours of electromyographic recordings. The presence of electromyographic activity of an amplitude 4 times the baseline, with a duration of more than 5 seconds, was taken to signify a spasm. The number of spasms per hour was calculated before and after PVS and no treatment. Spasticity was evaluated by the Modified Ashworth Scale (MAS). MAIN OUTCOME MEASURE: Reduction in spasticity and spasms. RESULTS: The electromyographic data showed a significant reduction in the frequency of leg spasms up to 3 hours (P<.05). Significantly decreased spasticity, as evaluated by MAS, was found immediately after vibration (P<.01). CONCLUSIONS: PVS may be useful as an antispastic therapy.     

Electrical simulation in addition to passive stretch has a small effect on spasticity and contracture in children with cerebral palsy: a randomised within-participant controlled trial

Question: Does electrical stimulation in addition to passive stretching reduce spasticity and contracture more than passive stretching alone in children with cerebral palsy? Design: Randomised within-participant controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis. Participants: Eleven (one dropout) children with cerebral palsy and bilateral knee flexor spasticity aged 13 years (SD 1). Intervention: One leg in each participant received the experimental intervention for four weeks which consisted of 30 min of electrical stimulation of the quadriceps 3 times per week and passive stretching of the hamstrings 5 times per week. The other leg received the control intervention for four weeks which consisted of passive stretching of the hamstrings 5 times per week. Outcome measures: Spasticity of the hamstrings was measured using the modified Ashworth scale. Contracture was measured as maximum passive knee extension using goniometry. Results: The mean difference in decrease in the modified Ashworth score due to the addition of electrical stimulation to the stretching regimen was 0.8 points (95% CI 0.1 to 1.5). The mean difference in increase in passive knee extension due to the addition of electrical stimulation to the stretching regimen was 4 degrees (95% CI 0 to 7). Conclusion: Electrical stimulation combined with passive stretching is marginally more effective than passive stretching alone for spastic limbs of children with cerebral palsy.     

The effect of quadriceps femoris muscle strengthening exercises on spasticity in children with cerebral palsy

BACKGROUND AND PURPOSE: The Bobath neurodevelopmental treatment approach advised against the use of resistive exercise, as proponents felt that increased effort would increase spasticity. The purpose of this study was to test the premise that the performance of exercises with maximum efforts will increase spasticity in people with cerebral palsy (CP). Spasticity, in the present study, was defined as a velocity-dependent hyperexcitability of the muscle stretch reflex. SUBJECTS: Twenty-four subjects with the spastic diplegic form of CP (mean age=11.4 years, SD=3.0, range=7-17) and 12 subjects without known neurological impairments (mean age=11.6 years, SD=3.5, range=7-17) were assessed. METHODS: Knee muscle spasticity was assessed bilaterally using the pendulum test to elicit a stretch reflex immediately before and after 3 different forms of right quadriceps femoris muscle exercise (isometric, isotonic, and isokinetic) during a single bout of exercise training. Pendulum test outcome measures were: (1) first swing excursion, (2) number of lower leg oscillations, and (3) duration of the oscillations. RESULTS: There were no changes in spasticity following exercise between the 2 groups of subjects. DISCUSSION AND CONCLUSION: These results do not support the premise that exercises with maximum efforts increase spasticity in people with CP.     

Reliability and validity of pendulum test measures of spasticity obtained with the Polhemus tracking system from patients with chronic stroke

Background  

Spasticity is a common impairment accompanying stroke. Spasticity of the quadriceps femoris muscle can be quantified using the pendulum test. The measurement properties of pendular kinematics captured using a magnetic tracking system has not been studied among patients who have experienced a stroke. Therefore, this study describes the test-retest reliability and known groups and convergent validity of the pendulum test measures obtained with the Polhemus tracking system.     

Augmenting voluntary torque of healthy muscle by optimization of electrical stimulation

The purpose of this study was to evaluate the ability of electrical stimulation (2,500-Hz sine waves, interrupted for 50 pulsed bursts per second) to improve muscle torque using low-dosage training characteristics. Fifteen healthy subjects (9 men, 6 women), 20 to 32 years of age, participated in the experiment. All subjects received electrical stimulation of the right anterior thigh musculature while their left leg served as the control. Electrical stimulation was repeated eight times per session, each stimulation producing isometric torque equal to 50% of the subject's maximum voluntary isometric contraction. The sessions were repeated twice a week over a period of five weeks. Results showed that electrical stimulation, when used with the specified low-dosage training characteristics of this study, will augment quadriceps femoris muscle torque of men.     

Correlation of knee extensor muscle torque and spasticity with gait speed in patients with stroke

The purpose of this investigation was to determine in 17 stroke patients the correlation between two independent variables (knee extensor muscle torque [KET] and spasticity on the paretic side) and one dependent variable (gait speed). The patients had a mean age of 59 years; time since onset of first stroke was 51 days. Each variable was measured twice on each of two consecutive days. Both KET and spasticity were measured on a Cybex II dynamometer. Peak torque was measured during five-second maximal voluntary isometric knee extension efforts. Spasticity was defined by the relative angle of reversal (RAR) of the Cybex electrogoniometer curve obtained during pendulum tests. Gait speed was measured as patients walked 8.0 meters at their most comfortable speed while using their usual devices. The average of each day's KETs, RARs, and gait speeds was used in the calculation of Pearson product moment correlations. The correlations between KET and gait speed were significant (p less than .05) and were .574 (day 1) and .571 (day 2). The correlations between the RAR and gait speed were not significant (-.204 day 1 and -.262 day 2). All measurements had intraday and/or interday reliability coefficients (ICC 3,1) exceeding .930. The results of this study confirm that gait performance is correlated with measures of KET but not spasticity in stroke patients. Thus, at the knee, extensor muscle torque, unlike spasticity, appears to be justified as a practical and objective clinical measure.     

Electrical stimulation versus electromyographic biofeedback in the recovery of quadriceps femoris muscle function following anterior cruciate ligament surgery

Both electrical stimulation and electromyographic biofeedback have been shown to be more effective than voluntary isometric exercise alone in the recovery of quadriceps femoris muscle force following anterior cruciate ligament (ACL) reconstruction. In a comparison of these two modalities, 30 patients with ACL reconstruction were randomly assigned to either a group receiving electrical stimulation in conjunction with voluntary isometric exercise or a group receiving biofeedback in conjunction with voluntary isometric exercise. Following 6 weeks of a rehabilitative exercise protocol, the quadriceps femoris muscle isometric peak torque in the operative limb was compared with that in the nonoperative limb. A t test of independent samples indicated that the biofeedback group recovered a significantly greater percentage of their nonoperative limb's peak torque than did the electrical stimulation group. Measurements of active knee extension were taken at weeks 1, 2, 4, and 6 of the exercise program. A two-way analysis of variance (groups x weeks) indicated no significant difference between the rate at which each group recovered full active extension. The authors concluded that biofeedback is more effective than electrical stimulation in facilitating the recovery of peak torque and that biofeedback is comparable to electrical stimulation in the recovery of active knee extension.     

Effect of electrical stimulation on spasticity in hemiparetic patients

Cyclical electrical stimulation has been applied to 10 hemiparetic patients with clinical signs of knee joint spasticity. The programme included 30 minutes of stimulation to the hamstrings followed by another 30 minutes of stimulation to the hamstrings and quadriceps. None of the patients experienced increased spasticity. The reduction in spasticity ranged from none to substantial with some other beneficial side-effects. No conclusions could be drawn as to whether hamstring stimulation is preferred to combined stimulation or to quadriceps stimulation alone. It is suggested that small portable stimulators be introduced for chronic use in spastic patients after an optimum stimulation regimen is individually established for each patient.     

Clinical Usefulness of the Pendulum Test Using a NK Table to Measure the Spasticity of Patients with Brain Lesions

. [Purpose] The purpose of the present study was to investigate the clinical usefulness (reliability and validity) of the pendulum test using a Noland-Kuckhoff (NK) table with an attached electrogoniometer to measure the spasticity of patients with brain lesions. [Subjects] The subjects were 31 patients with stroke or traumatic brain injury. [Methods] The intraclass correlation coefficient (ICC) was used to verify the test–retest reliability of spasticity measures obtained using the pendulum test. Pearson''s product correlation coefficient was used to examine the validity of the pendulum test using the amplitude of the patellar tendon reflex (PTR) test, an objective and quantitative measure of spasticity. [Results] The test–retest reliability was high, reflecting a significant correlation between the test and the retest (ICCs = 0.95–0.97). A significant negative correlation was found between the amplitude of the PTR test and the four variables measured in the pendulum test (r = −0.77– −0.85). [Conclusion] The pendulum test using a NK table is an objective measure of spasticity and can be used in the clinical setting in place of more expensive and complicated equipment. Further studies are needed to investigate the therapeutic effect of this method on spasticity.Key words: NK table, Pendulum test, Spasticity     

Effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with knee osteoarthritis

[Purpose] The aim of this study was to investigate the effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with osteoarthritis of the knee. [Subjects] Thirty women over 65 years of age diagnosed with knee osteoarthritis participated in the present study. The subjects were randomly assigned to a control group (n=10), a progressive resistance training group (n=10), or a Russian electrical stimulation group (n=10). [Methods] Each group was treated 3 times weekly for 8 weeks, and each session lasted 45 minutes. Muscle strength was assessed by measuring the peak torque of the quadriceps femoris muscle. Outcome measurements were performed at baseline and at the fourth and eighth weeks of the treatment period. [Results] All groups showed significant intragroup differences in the quadriceps femoris muscle peak torque after the treatment intervention. There were significant intergroup differences between the Russian electrical stimulation group and the other groups. [Conclusion] The results of this study suggest that combined application of progressive resistance training and Russian electrical stimulation can be effective in strengthening the quadriceps femoris muscle in elderly women with knee osteoarthritis.Key words: Knee osteoarthritis, Progressive resistance training, Russian electrical stimulation     

电刺激治疗痉挛型双瘫患儿疗效的表面肌电分析

目的应用表面肌电图对脑瘫患儿电刺激前后的肌电活动进行分析。方法对20例痉挛型双瘫患儿进行功能性电刺激,并于治疗前后分别用临床方法和表面肌电仪进行评估。结果治疗后患儿功能位测试肱二头肌、股四头肌的肌电积分降低,而自主收缩测试的肌电积分升高。结论经电刺激治疗可使患儿肌张力降低,肌力增强。表面肌电仪可以作为电刺激治疗痉挛型双瘫患儿的疗效客观评估方法。     

Changes in knee motion pattern after anterior cruciate ligament injury - case report

BACKGROUND: After an anterior cruciate ligament injury, the contra-lateral non-injured leg has been found to adapt towards the injured leg. Accordingly, in order to study changes in knee motion pattern after an anterior cruciate ligament injury, the ideal is to compare the same leg prior to and after the injury. However, this is very seldom possible. The purpose of the present study was to describe changes in static and dynamic sagittal tibial translation, electromyographic activity and muscle torque relevant to an anterior cruciate ligament tear in one patient evaluated both before and after the injury. METHODS: A male soccer player was examined 11 weeks before and eight weeks after an anterior cruciate ligament injury. Sagittal tibial translation was measured with the CA-4000 electrogoniometer; statically during Lachman's test, and dynamically during isokinetic muscle testing, one-legged squat and level walking. The electromyographic activity of mm. quadriceps and hamstrings, was registered simultaneously during the one-legged squat test. FINDINGS: Static tibial translation was increased by approximately 2 mm, while dynamic tibial translation was decreased by 0.4 mm at isokinetic testing, 0.9 mm at one-legged squat and 2.4 mm during level walking compared to before the injury. Muscle torque decreased 30% and 35% for the quadriceps and the hamstrings muscle, respectively. The electromyographic activity revealed similar activation levels in quadriceps and a doubled level of activation in hamstring compared to before the injury. INTERPRETATION: In spite of an increase in static tibial translation eight weeks after an anterior cruciate ligament injury, the tibial translation decreased during activity, thus indicating that the patient could stiffen the knee in order to protect it against increased shear forces.     

Treatment of Spasticity in Spinal Cord Injury with Dronabinol, a Tetrahydrocannabinol Derivative

Spinal-cord-injured patients and the medical literature have increasingly reported anecdotes regarding tetrahydrocannabinol (THC)-induced spasmolysis. These reports motivated this trial of dronabinol, a THC derivative, for the treatment of spasticity in the spinal-cord-injured population. Five made quadriplegic patients were given oral dronabinol in escalating doses from 5 mg BID to 20 mg TID in addition to their current, but ineffective, spasmolytic regime. The pendulum drop test was used to quantify spasticity (stiffness) in the knees. The Weschler Memory Scale (WMS), Profile of Mood States (POMS), and personal interviews were administered by the clinical psychologist to evaluate any changes in the subjects' cognition and/or emotional states. Spasticity was markedly improved in two of the five subjects, unchanged in a third, fluctuated in a fourth and made progressively worse in a fifth. The WMS revealed improvement in memory skills of two subjects and no change in the other. Psychological interviews and the POMS indicated decreased vigor in all subject, but otherwise demonstrated highly individualized emotional changes as indicated by increases and/or decreases in the dysphoric mood scales.     

Increased spasticity in a chronic spinal cord injury patient after scabies infestation: A case report

Spasticity is a common feature of spinal cord injury (SCI). Spasticity exacerbation is commonly encountered with nociceptive and exteroceptive stimuli including bladder and bowel dysfunction, pressure sores, contracture, tight-fitting leg bags and clothing, and ingrown toenail. This report describes a patient with chronic SCI (T4 level) who complained of increasing spasticity of bilateral lower extremities for 5 weeks. He also had skin lesions on different parts of his body, accompanied by itching above the spinal cord lesion level. A clinical diagnosis of scabies was made and pharmacologic treatment was initiated. Following treatment, spasticity was significantly reduced and the skin rash with itching faded out. This report is the first of scabies skin infestation lesions triggering exacerbation of spasticity in an SCI patient.     

Maximizing muscle force via low-cadence functional electrical stimulation cycling.

OBJECTIVE: This study investigated the effect of pedal cadence upon torque production, power output and muscle fatigue rates during functional electrical stimulation evoked cycling in spinal cord injured individuals. SUBJECTS: All subjects had complete thoracic spinal cord injuries T4-T9 (ASIA A) and had been functional electrical stimulation training regularly for at least 6 months. METHODS: One trial (n = 8) examined a low vs high pedal rate (20 and 50 rev x min(-1)) upon isolated muscle fatigue over 5 minutes. A second trial (n = 9) investigated the effect of cadence (15 vs 50 rev x min(-1)) upon performance during 35-minutes of functional electrical stimulation evoked cycling. RESULTS: Peak torque produced by left quadriceps decayed significantly faster at the higher pedal cadence, indicating a higher rate of muscle fatigue. Functional electrical stimulation cycling over 35 minutes also revealed that peak and average torques were significantly greater at the lower cadence. From 15 minutes onwards, power output was significantly higher at 50 rev x min(-1) FES-cycling, compared with 15 rev x min(-1). CONCLUSION: The higher muscle forces observed during low cadence functional electrical stimulation cycling should offer improvements over traditional pedalling velocities for training leg strength in individuals with spinal cord injury.