Clinical Measures Of Spasticity Research Articles

A randomized, double-blind, placebo-controlled trial to evaluate the effect of nabiximols oromucosal spray on clinical measures of spasticity in patients with multiple sclerosis

BackgroundSpasticity is a common and potentially debilitating symptom of multiple sclerosis (MS) with a highly variable presentation. Understanding, quantifying, and managing MS-associated spasticity (MSS) is a challenge for research and in clinical practice. The tetrahydrocannabinol:cannabidiol oromucosal spray nabiximols has demonstrated beneficial effects in the treatment of MSS in clinical studies as well as real-world observational studies, and is approved for the treatment of MSS in 29 countries globally. Most randomized studies evaluated the efficacy of nabiximols using the change in average daily spasticity scores reported by patients using the spasticity Numeric Rating Scale as a primary endpoint. This study, RELEASE MSS1 (NCT04657666), was conducted using a prespecified primary endpoint of change in spastic muscle tone (Modified Ashworth Scale Lower Limb Muscle Tone-6 [MAS LLMT-6]) to corroborate the efficacy of nabiximols as adjunctive therapy observed with the patient-measured spasticity Numeric Rating Scale primary endpoint in the previous pivotal studies. MethodsThis was a phase 3, multicenter, randomized, double-blind, placebo-controlled, 2-treatment, 2-period, crossover trial. Because of the prevalence and functional impact of lower limb spasticity on the individual patient's overall experience of MS spasticity, the MAS LLMT-6 was derived from the clinician-rated MAS. The MAS LLMT-6 is the average transformed MAS score of 6 muscle groups (knee flexors, knee extensors, and ankle plantar flexors; all assessed bilaterally). Secondary measures included MAS LLMT-4 scores, defined as the average of the 4 individual MAS-transformed scores of knee flexors and knee extensors bilaterally. Patients had a diagnosis of MS and an untransformed MAS score of at least 2 in ≥2 of 6 LLMT-6 muscle groups despite current treatment with ≥1 of the following oral antispasticity agents: baclofen, tizanidine, or dantrolene. Eligible participants were randomly assigned to 1 of 2 treatment sequences. Each treatment sequence consisted of two treatment periods, each consisting of a 14-day dose titration phase followed by a 7-day dose maintenance phase. ResultsOf 68 patients enrolled, 33 were assigned to nabiximols followed by placebo and 35 were assigned to placebo followed by nabiximols. Least squares mean changes in MAS LLMT-6 scores from baseline to day 21 were −0.23 for nabiximols and −0.26 for placebo; the least squares mean treatment difference in MAS LLMT-6 scores for nabiximols versus placebo was 0.04, which was not statistically significant (P = 0.7152). Mean changes in MAS LLMT-4 scores from baseline to day 21 also were not significantly different between the nabiximols and placebo groups. Safety results in this study were consistent with the known safety profile of nabiximols in patients with MSS. ConclusionDespite the established efficacy of nabiximols in MSS observed using patient-reported measures, the primary endpoint was not met in this study. The findings from this study reflect and emphasize some of the challenges in the evaluation and treatment of MS spasticity. Clinical trial registration number (ClinicalTrials.gov): NCT04657666

Self-modulation of rectus femoris reflex excitability in humans

Hyperreflexia is common after neurological injury such as stroke, yet clinical interventions have had mixed success. Our previous research has shown that hyperreflexia of the rectus femoris (RF) during pre-swing is closely associated with reduced swing phase knee flexion in those with post-stroke Stiff-Knee gait (SKG). Thus, reduction of RF hyperreflexia may improve walking function in those with post-stroke SKG. A non-pharmacological procedure for reducing hyperreflexia has emerged based on operant conditioning of H-reflex, an electrical analog of the spinal stretch reflex. It is currently unknown whether operant conditioning can be applied to the RF. This feasibility study trained 7 participants (5 neurologically intact, 2 post-stroke) to down-condition the RF H-reflex using visual feedback. We found an overall decrease in average RF H-reflex amplitude among all 7 participants (44% drop, p < 0.001, paired t-test), of which the post-stroke individuals contributed (49% drop). We observed a generalized training effect across quadriceps muscles. Post-stroke individuals exhibited improvements in peak knee-flexion velocity, reflex excitability during walking, and clinical measures of spasticity. These outcomes provide promising initial results that operant RF H-reflex conditioning is feasible, encouraging expansion to post-stroke individuals. This procedure could provide a targeted alternative in spasticity management.

Measuring Mechanical Properties of Spastic Muscles After Stroke. Does Muscle Position During Assessment Really Matter?

ObjectiveTo investigate the influence of muscle position (relaxed vs stretched) on muscle mechanical properties and the ability of myotonometry to detect differences between sides, groups, and sites of testing in patients with stroke. We also analyzed the association between myotonometry and clinical measures of spasticity. DesignCross-sectional study. SettingOutpatient rehabilitation units including private and public centers. ParticipantsSeventy-one participants (20 subacute stroke, 20 chronic stroke, 31 controls) were recruited (N=71). InterventionMuscle mechanical properties were measured bilaterally with a MyotonPRO at muscle belly and musculotendinous sites during 2 protocols (muscle relaxed or in maximal bearable stretched position). Main Outcome MeasuresMuscle tone and stiffness of the biceps brachii and gastrocnemius. Poststroke spasticity was evaluated with the Modified Tardieu Scale (MTS). A mixed-model analysis of variance was used to detect differences in the outcome measures. ResultsThe analysis of variance showed a significant effect of muscle position on muscle mechanical properties (higher tone and stiffness with the muscle assessed in stretched position). Measurements with the stretched muscle could help discriminate between spastic and nonspastic sides, but only at the biceps brachii. Overall, there was a significant increase in tone and stiffness in the chronic stroke group and in myotendinous sites compared with muscle belly sites (all, P<.05). No correlations were found between myotonometry and the MTS. ConclusionsMyotonometry assessment of mechanical properties with the muscle stretched improves the ability of myotonometry to discriminate between sides in patients after stroke and between people with and without stroke.

Prevalence and predictors for the ability to run in children and adolescents with cerebral palsy

BackgroundRunning is a fundamental movement skill and a prerequisite for children to participate in numerous daily activities. The prevalence of the ability to run in people with Cerebral Palsy and the role of their impairments on running ability are unknown. Therefore, the aim of this study is to determine the prevalence of the ability to run and to identify contributing factors. MethodsIn this study, 280 children and adolescents with spastic Cerebral Palsy, Gross Motor Function Classification System level II were included. The ability to run was defined by instrumented running analysis. Runners and non-runners were compared regarding their clinical measures of spasticity, weakness, and postural control. Logistic regression was applied to identify the most important predictors for the ability to run. FindingsThe ability to run was significantly higher in unilateral (67%) than in bilateral (55%) affected patients. Significant differences between runners and non-runners were found for spasticity, BMI and postural control, but not for muscle strength. Lower M. rectus femoris spasticity, higher m gastrocnemius spasticity and enhanced postural control appear to be the best predictors for being able to run. InterpretationPatients with Gross Motor Function Classification System level II represent a large group in the gait laboratory and the functional impairment within this group differs greatly. Therefore, for clinical decision making we suggest to separate patients in this group based on their running ability. Spasticity and postural control affect the ability to run and needs to be accounted for in intervention programs.

Development of the Persian version of the Modified Modified Ashworth Scale: translation, adaptation, and examination of interrater and intrarater reliability in patients with poststroke elbow flexor spasticity

Purpose: Development of the Persian version of the Modified Modified Ashworth Scale (MMAS), and to investigate the interrater and intrarater reliability of the Persian MMAS when used to quantify elbow flexor spasticity in patients after stroke. Methods: The Persian MMAS was developed by the forward and backward translation procedure, a final review by an expert committee, and testing for acceptability and the clarity of item wording so that the scale could be used by Persian-speaking examiners. Psychometric testing included interrater and intrarater reliability. Elbow flexor spasticity was examined by two raters in 30 patients after stroke twice on two occasions using the Persian MMAS. The weighted κ was used for the statistical analysis. Results: The interrater and intrarater reliability was very good for the Persian MMAS (weighted κ: 0.81–0.91; 95% CI 0.68–0.98) with statistically significant agreement between raters and within raters (all p < 0.001). Conclusions: The Persian version of the MMAS was successfully developed. The Persian MMAS showed very good interrater and intrarater reliability in patients with elbow flexor spasticity after stroke. The results support the use of the Persian version of the MMAS both in clinical and research settings.Implications for RehabilitationThe new Modified Modified Ashworth Scale (MMAS) is a clinical measure of spasticity, which was published in 2006 by Ansari et al.The MMAS was successfully translated and adapted into a Persian version. The Persian version of the MMAS showed very good interrater and intrarater reliability comparable to the original English version. The Persian version of the MMAS can be recommended for the assessment of muscle spasticity in Persian-speaking countries.

Decrease of spasticity with muscle vibration in patients with spinal cord injury

Objective Spasticity is common after spinal cord injury (SCI). Exaggerated tendon jerks, clonus, and spasms are key features of spasticity that result from hyperexcitability of the stretch reflex circuit. Here we studied the effects of vibration on the rectus femoris muscle (RF) on clinical and electrophysiological measures of spasticity in the leg. Methods Nineteen SCI patients with spasticity and nine healthy subjects were studied at baseline and under stimulation (vibration at 50 Hz during 10 min on the thigh). Neurophysiological studies included evaluation of the soleus T wave and Hmax/Mmax ratio. Clinical measurements of spasticity were the score in the Modified Ashworth Scale (MAS), range of motion (ROM), and duration and frequency of clonus. Results Patients with incomplete SCI (iSCI) presented higher number of cycles and longer duration of clonus than patients with complete SCI (cSCI). The Hmax/Mmax ratio and T wave amplitude at baseline were significantly larger in iSCI patients than in cSCI or healthy subjects. During vibration, we found a significant reduction of MAS and duration of clonus, and an increase in ROM, in all patients as a group. The Hmax/Mmax ratio and the T wave amplitude decreased significantly in both, patients and controls. Conclusions Prolonged vibration on proximal lower extremity muscles decreased limb spasticity in patients with spinal cord injury, regardless of whether the lesion is complete or incomplete. Significance Muscle vibration may be useful for physical therapy, by facilitating passive and active movements of the extremities in spastic SCI patients.

Soleus H-Reflex Modulation After Motor Incomplete Spinal Cord Injury: Effects of Body Position and Walking Speed

Objective: To examine position-dependent (semireclined to standing) and walking speed-dependent soleus H-reflex modulation after motor incomplete spinal cord injury (SCI).Participants: Twenty-six patients with motor incomplete SCI (mean: 45 ± 15 years) and 16 noninjured people (mean: 38 ± 14 years).Methods: Soleus H-reflexes were evoked by tibial nerve stimulation. Patients were tested in semireclined and standing positions (experiment 1) and in midstance and midswing positions (experiment 2).Results: H-reflexes were significantly greater after SCI in all positions compared with noninjured people (P < 0.05). Position-dependent modulation from semireclined to standing (normally observed in noninjured people) was absent after SCI. In SCI patients, H-reflex modulation was not significantly different at 1.2 m/s compared with 0.6 m/s treadmill walking speed; in noninjured people, H-reflex modulation was significantly greater at 1.2 m/s compared with 0.6 m/s treadmill walking speed. There was a significant positive correlation between modified Ashworth scores, a clinical measure of spasticity and soleus H-reflex amplitudes tested in all positions. A significant negative correlation was also found between H-reflexes in standing and midstance positions and the amount of assistance patients required to walk.Conclusions: An improvement in position-dependent and walking speed-dependent reflex modulation after SCI may indicate functional recovery. Future studies will use H-reflex testing to track changes as a result of therapeutic interventions.

Quantitative Measurement of Poststroke Spasticity and Response to Treatment With Botulinum Toxin: A 2-Patient Case Report

Spasticity (hypertonicity) is a frequent problem that can develop after stroke and can lead to a number of secondary complications, such as contractures and pain. Consequently, many rehabilitation resources are used in treating the condition and its secondary complications. At present, the clinical assessment of spasticity incorporates descriptive scales of resistance to passive movement, but the use of a neurophysiological measure of muscle activity levels has been advocated. This case report focuses on the diagnosis of spasticity through the use of a neurophysiological measure. . Two individuals who required botulinum toxin treatment for poststroke spasticity were assessed over a course of 20 weeks with both clinical (Modified Ashworth Scale) and neurophysiological (surface electromyography recording of levels of muscle activity) measures of spasticity. Additionally, arm function, arm movement, and pain were measured. The individuals' responses to treatment with botulinum toxin and overall recovery after stroke are described. There were discrepancies between the clinical and the neurophysiological measures of spasticity. The clinical measure of spasticity was not effective in consistently identifying the presence of spasticity and, therefore, also was ineffective in documenting the individuals' responses to treatment. The neurophysiological measure was able to identify when muscle activity levels had been reduced, but a reduction in muscle activity levels did not always correspond with a reduction in Modified Ashworth Scale scores. The accurate identification of spasticity is important not only for assessment but also for the selection of appropriate treatments after stroke.

Efficacy of therapeutic ultrasound and infrared in the management of muscle spasticity

Primary objective: This study was designed to compare the short-term effects of infrared (IR) and therapeutic ultrasound (US) on clinical and electrophysiological measures of spasticity and range of motion (ROM) in hemiplegic patients with plantar flexor muscle spasticity.Research design: A cross-sectional, single centre trial.Interventions: Ultrasound and Infrared were used.Methods and procedures: Twenty-one patients (13 males and eight females) aged 27–78 years (mean ± SD: 60.4 ± 13.2) were randomly assigned into either the US or IR treatment groups. The IR and US were delivered for 20 and 10 minutes, respectively. The H-reflex, Ashworth scale (AS) and ROM were collected before, immediately after and 15 minutes after the end of the treatment.Main outcomes and results: Both groups were statistically similar on all variables at the beginning of the study. Results indicated that the dependent variables were not significantly different between groups at the end of study. The use of IR and US was not associated with significant reductions of H-reflex and Ashworth scores. A significant main effect for time on active and passive ROM was obtained.Conclusions: It was concluded neither IR nor US reduced electrophysiological or clinical measures of spasticity in this sample of patients.

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° • 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.

Separate Quantification of Reflex and Nonreflex Components of Spastic Hypertonia in Chronic Hemiparesis

Chung SG, van Rey E, Bai Z, Rymer WZ, Roth EJ, Zhang L-Q. Separate quantification of reflex and nonreflex components of spastic hypertonia in chronic hemiparesis. Objectives To isolate and quantify reflex and nonreflex components of the spastic ankle plantarflexors in hemiplegia poststroke and to correlate them with clinical measures of spasticity, which may involve hyperactive stretch reflex and/or increased joint stiffness. Design To investigate reflex and nonreflex properties associated with spasticity in a case-control manner. Setting Research laboratory in a rehabilitation hospital. Participants Hemiplegic patients (n=17) and the same number of healthy subjects. Interventions Not applicable. Main Outcome Measures Tendon reflexes of spastic muscles were evaluated under an isometric condition, which essentially eliminated passive viscoelastic contributions associated with limb movement. Nonreflex components of spasticity were evaluated by moving the ankle joint slowly, which minimized reflex actions. The reflex and nonreflex measures were investigated and correlated with each other and with clinical measures. Results Compared with healthy subjects, patients with stroke showed a lower reflex threshold, higher electromyographic gains, and torque reflex gains, indicating hyperactive reflexes. For nonreflex properties, ankles of stroke patients showed higher stiffness, reduced range of motion (ROM), and larger resistant torque at comparable positions, reflecting peripheral soft-tissue changes at the ankle of the chronic stroke patients. Furthermore, the clinical reflex score correlated with all of the quantitative reflex measures but not with the nonreflex measures, whereas the dorsiflexion ROM showed a significant correlation with a nonreflex measure. The Modified Ashworth Scale was correlated with all of the reflex measures and 1 of the nonreflex measures. Conclusions Comprehensive and convenient evaluation of spasticity should be performed quantitatively with the separate measures of reflex and nonreflex components, especially in chronic conditions. With proper simplifications, the current method of separate quantification can potentially be used for convenient clinical evaluations of spasticity.

The Tardieu Scale differentiates contracture from spasticity whereas the Ashworth Scale is confounded by it

Objective: To compare the Tardieu Scale as a clinical measure of spasticity after stroke with the Ashworth Scale. Design: Cross-sectional study. Participants: Sixteen people, living in the community three years after their stroke. Main measures: The Ashworth Scale and Tardieu Scale as well as laboratory measures of spasticity (stretch-induced electromyographic (EMG) activity) and contracture (maximum passive joint excursion) were collected from the affected elbow flexors and extensors and ankle plantarflexors and dorsiflexors by three examiners who were blinded to the results of the other measures. Results: The percentage exact agreement (PEA) between the Tardieu Scale and a laboratory measure of spasticity was 100% for both the elbow flexors and ankle plantarflexors. This was significantly (P=0.02) greater than the PEA of 63% for both muscles between the Ashworth Scale and the same laboratory measure of spasticity. For contracture, the PEA between the Tardieu Scale and a laboratory measure was 94% for both the elbow flexors and the ankle plantarflexors. Pearson correlation coefficients between the Tardieu Scale and laboratory measures of spasticity were 0.86 for the elbow flexors and 0.62 for the ankle plantarflexors and between the Tardieu Scale and laboratory measures of contracture were 0.89 for the elbow flexors and 0.84 for the ankle plantarflexors. Conclusion: In all cases that spasticity was overestimated by the Ashworth Scale, participants had a contracture. These findings suggest that the Tardieu Scale differentiates spasticity from contracture whereas the Ashworth Scale is confounded by it.

A systematic review of the Tardieu Scale for the measurement of spasticity

Background. The Tardieu Scale has been suggested a more appropriate clinical measure of spasticity than the Ashworth or modified Ashworth Scales. It appears to adhere more closely to Lance's definition of spasticity as it involves assessment of resistance to passive movement at both slow and fast speeds.Objective. To review the available literature in which the Tardieu Scale has been used or discussed as a measure of spasticity, with a view to determining its validity and reliability.Study design. A systematic review of all literature found related to the Tardieu Scale (keywords: Tardieu scale, spasticity) from Pubmed and Ovid databases, including medline, CINAHL, EMBASE, Journals at Ovid full text, EBM reviews and Cochrane database of systematic reviews. Hand searching was also used to track the source literature.Conclusions. In theory, we can acknowledge that the Tardieu Scale does, in fact, adhere more closely to Lance's definition of spasticity. However, there is a dearth of literature investigating validity and reliability of the scale. Some studies have identified the Tardieu Scale to be more sensitive than other measures, to change following treatment with botulinum toxin. Further studies need to be undertaken to clarify the validity and reliability of the scale for a variety of muscle groups in adult neurological patients.

The Drawing Test: Assessment of coordination abilities and correlation with clinical measurement of spasticity

Eder CF, Popović MB, Popović DB, Stefanović A, Schwirtlich L, Jović S. The Drawing Test: assessment of coordination abilities and correlation with clinical measurement of spasticity. Objective To assess the correlation between kinematic measures of movement (Drawing Test) and a clinical measure of spasticity (Ashworth Scale). Design Correlation study of Drawing Test and the Ashworth Scale scores. Setting Inpatient rehabilitation center. Participants Forty-five poststroke hemiplegic subjects with various levels of spasticity (up to Ashworth Scale score of 3) and 8 able-bodied subjects with no sensorimotor deficits in their upper extremities. Interventions Subjects made self-paced, radial point-to-point movements between the left, and the right corners of a square (200×200mm) on the surface of a drawing tablet. Hand coordinates were recorded from the mouse, which was attached to the hand. Main outcome measures Correlation between (1) Drawing Test scores (time to perform the movement, radial [ y] and tangential [ x] distances between the end point of the movement and the target endpoint, standard error of the mean calculated as distances between the recorded path and its radial linear fit), and (2) Ashworth Scale scores. Results Drawing Test scores correlated highly with Ashworth Scale scores in 49 of 53 subjects, based on the multiple linear regression analysis. Conclusions The Drawing Test, a quantitative metric of movement ability, correlated highly to the Ashworth Scale, a clinical measure of spasticity.

The Effects of Serial Casting on Spasticity: A Literature Review

This article is a literature review of the research regarding the use of serial casting in the treatment of spasticity. Spasticity has serious consequences, which impact activities of daily living and the quality of life. Classical studies in physiology indicate that muscle tissue immobilized in the shortened position can be physiologically changed through prolonged stretch. Serial casting has proven effective in improving such factors as range of motion and clinical measures of spasticity in spastic limbs. Further research is needed to determine the most effective uses of serial casts in the treatment of spasticity.

132. A Simple Technique to Quantify Resistance to Passive Movement: A First Step Toward Developing an Objective Clinical Measure of Spasticity A. D. Pandyan, C. I. M. Price, R. Curless, M. P. Barnes, and G. R. Johnson (all from Newcastle upon Tyne, UK

132. A Simple Technique to Quantify Resistance to Passive Movement: A First Step Toward Developing an Objective Clinical Measure of Spasticity A. D. Pandyan, C. I. M. Price, R. Curless, M. P. Barnes, and G. R. Johnson (all from Newcastle upon Tyne, UK

Simultaneous ashworth measurements and electromyographic recordings in tetraplegic patients

Objective: A recent prevalence study of 353 spinal cord injured (SCI) individuals in the greater Stockholm area showed problematic spasticity in 30% of this population. To treat spasticity, the evaluation becomes crucial. The modified Ashworth scale (MAS) is the clinically most-used scale to grade degree of spasticity. This study evaluated whether the MAS correlated with electromyographic (EMG) recordings of muscle activity. Study Design: This cross-sectional study was performed at an outpatient clinic that has the responsibility to do a standardized, yearly follow-up of all SCI patients in the greater Stockholm area. Thirty-eight SCI individuals met the inclusion criteria; 15 of the 38 were randomly selected for the study. They were all motor-complete tetraplegic men; mean age was 33 years and mean time since injury was 9 years. Spasticity evaluation was performed by flexing and extending the knees during simultaneous EMG recordings and MAS assessment of the thigh muscle activity. Results: Eighty percent of the individual EMG recordings correlated significantly with the corresponding Ashworth measurements. The spastic resistance, as measured both clinically and electromyographically, was stronger and lasted longer during extension than flexion movements. Spearman coefficients for correlation of quantitative spasticity measures with MAS grades were calculated. EMG and clinical measures of spasticity were more closely correlated for flexion movements. Among EMG parameters, duration of movement-associated electrical activity invariably correlated significantly with the MAS grades ( p < .05). Furthermore, Ashworth measurements of movement-associated spasticity showed a positive correlation with the EMG parameters mean, peak, and start to peak of electrical activity. Each increasing grade on the MAS corresponded to increasing myoelectric activity levels for each movement. Conclusion: EMG parameters were significantly positively correlated with simultaneous MAS measurements of the spastic muscle contraction. The Ashworth scale may therefore accurately reflect the movement-provoked spasticity in motor-complete tetraplegic patients.

The efficacy of upper extremity inhibitive casting: a single-subject pilot study.

This pilot study was designed to examine the effects of short-term (48-hr) upper extremity inhibitive casting, with an encased thermoplastic splint, on problems related to upper motor neuron damage. The subject was an 8 1/2-year-old girl with left upper extremity spasticity. Three different measures were used: (a) rating of videotaped active movements of the child; (b) the Modified Ashworth Scale, a clinical measure of spasticity; and (c) The Biodex System, a measure of torque during passive elbow flexion and extension. After cast removal, subjective improvements were noted in the quality of active movement (through videotapes) and increased awareness and use of the casted hand by the child (through parents' reports). A trend toward decreased spasticity was demonstrated by the Modified Ashworth Scale and a statistically significant decrease in resistance to passive movement was shown by the Biodex recordings. However, this reduction in symptoms was temporary, lasting less than 3 days. The results of this study suggest that short-term inhibitory casting may prove efficacious in the treatment of the child with cerebral palsy, although further research is needed.

Recurrent inhibition is increased in patients with spinal cord injury.

Mechanisms underlying the development of spasticity after spinal cord injury are not understood. One spinal interneuron likely to be affected is the Renshaw cell, which acts to produce recurrent inhibition in motor neurons as well as inhibiting Ia interneurons. Descending pathways exert both excitatory and inhibitory control over Renshaw cell activity. We studied Renshaw cell activity in normal subjects and in patients with varying levels of spasticity after spinal cord injury using the conditioned H-reflex technique of Pierrot-Deseilligny and Bussel. A submaximal stimulus to the tibial nerve is presented prior to a supramaximal stimulus so that action potential collision permits an H reflex (H') to be elicited in response to the supramaximal stimulus. The amplitude of this H' reflex is affected by activity in recurrent inhibitory pathways. Patients with both complete and partial spinal cord lesions were studied; date of injury ranged from 1 month to 216 months prior to evaluation. In the 18 patients in whom H reflexes could be recorded, H' reflexes were absent in 13, in contrast to their uniform presence in normal subjects. We conclude that recurrent inhibition via Renshaw cell activity is increased in spinal cord injury, and that measures of recurrent inhibition may correlate well with some clinical measures of spasticity.