Michael M. Priebe

Clinical assessment of spasticity in spinal cord injury: A multidimensional problem☆

OBJECTIVEnTo determine the relation between various components of spasticity evaluated clinically in persons with spinal cord injury (SCI).nnnDESIGNnCase series evaluating spasticity using clinical scales commonly referenced in contemporary literature, including the Penn Spasm Frequency Scale, the Ashworth Scale, and standard scales of tendon taps, clonus, and plantar stimulation. SETTING. A Veterans Affairs Medical Center Spinal Cord Injury Center. PATIENTS. Eighty-five spinal cord injured individuals with varying degrees of spasticity.nnnRESULTSnCorrelations demonstrated weak relationships between Spasm Frequency Scale and self-report scales of interference with function (.407) and painful spasms (.312). No clinical examination score correlated with self-report scores greater than 0.4. Three clinical examination scores correlated modestly (> 0.5)-Ashworth score with patellar tendon taps (.553), ankle clonus with Achilles tendon tap (.663), and patellar tendon tap with adductor tendon tap (.512). Two other clinical scales correlated weakly (> 0.4)-Achilles tendon tap with patellar tendon tap (.417) and plantar reflex with adductor tendon taps (.423).nnnCONCLUSIONSnClinical scales currently used to evaluate spasticity in SCI correlate poorly with each other, suggesting that they each assess different aspects of spasticity. The use of any single scale is likely to underrepresent the magnitude and severity of spasticity in the SCI population. In the absence of agreement among these various scales and with the absence of an appropriate criterion standard for evaluation of spasticity, assessments of spasticity, whether clinical or neurophysiological in nature, should be comprehensive in scope.

Clinical neurophysiological assessment of residual motor control in post-spinal cord injury paralysis.

Objective. This study was designed to characterize the rudimentary residual lower-limb motor control that can exist in clinically paralyzed spinal-cord-injured individuals. Methods. Sixty-seven paralyzed spinal-cord-injured subjects were studied using surface electromyography recorded from muscles of the lower limbs and analyzed for responses to a rigidly administered protocol of reinforcement maneuvers, voluntary movement attempts, vibration, or the ability to volitionally suppress withdrawal evoked by plantar surface stimulation. Results. Markers for the subclinical discomplete motor syndrome were found in 64% of the subjects. The tonic vibration response was recorded in 37%, volitional plantar surface stimulation response suppression in 27%, and reinforcement maneuver responses in 6% of the subjects. Three subjects, 4%, produced reliable but very low amplitude surface electromyography during the voluntary movement segment of the protocol. Surface electromyography recorded during passive leg movement was related to Ashworth scores as was the tonic vibration response marker (P < 0.05). Conclusions. Multimuscle surface electromyography patterns recorded during a rigidly administered protocol of motor tasks can be used to differentiate between clinically paralyzed spinal-cord-injured individuals using subclinical motor output to identify the translesional neural connections that remain available for intervention testing and treatment planning after spinal cord injury.

THE ROLE OF OXYBUTYNIN IN SPINAL CORD INJURED PATIENTS WITH INDWELLING CATHETERS

PURPOSEnThe long-term benefits of oral oxybutynin in spinal cord injured patients with indwelling catheters is unknown. We reviewed our experience with this population of men and present the results of our analysis.nnnMATERIALS AND METHODSnA total of 109 male spinal cord injured patients at the Houston Veterans Affairs Medical Center have been treated with chronic indwelling catheters (80 transurethral and 29 suprapubic). Thirty-eight patients (35%) were identified as using oxybutynin on a regular basis. These patients were compared to those not using oxybutynin with regard to urodynamic parameters and upper tract deterioration. Specifically examined were bladder compliance, bladder leak point pressure, vesicoureteral reflux, hydronephrosis, urolithiasis, febrile urinary tract infections and serum creatinine greater than 2 mg./dl.nnnRESULTSnThe mean duration of indwelling catheter use was 11.9 years (12.4 without oxybutynin and 10.9 on oral oxybutynin). Of the 31 patients with normal compliance (greater than 20 ml./cm. water), 24 (77%) were using oxybutynin (p = 0.001). Bladder leak point pressures were abnormal (greater than 35 cm. water) in 5 of 32 patients (16%) on oxybutynin versus 34 of 60 (57%) without it (p <0.001). Hydronephrosis was present in 15 of 66 patients (23%) without oxybutynin versus 1 of 36 (3%) with oxybutynin (p = 0.009). Febrile urinary tract infections occurred in 4 of 35 patients (11%) versus 17 of 62 patients (27%) with or without oxybutynin, respectively (p = 0.077). No significant differences were found between the 2 groups with regard to reflux, renal scars, stones or elevated serum creatinine.nnnCONCLUSIONSnIt appears that regular use of oxybutynin may be beneficial in spinal cord injured patients who require chronic indwelling catheters for bladder management. Our analysis reveals that patients who take oxybutynin regularly have better bladder compliance, lower bladder leak point pressures and less hydronephrosis. Until a prospective, randomized trial reveals contradicting outcomes, empiric use of oxybutynin in all spinal cord injured patients requiring chronic indwelling catheters seems justified.

Predicting consistency of pain over a 10-year period in persons with spinal cord injury

This longitudinal study was designed to test the hypothesis that persons who consistently report pain at three (women) or four (men) measurement points across 10 years (1988 to 1998) are different both physically and psychologically from those who inconsistently or never report pain. Participants were 96 persons with spinal cord injury (SCI) living in the community who participated at every measurement point. Measures included consistency of reports of pain (i.e., reported having had problems with pain in the 12 months prior to all, some, or no measurement points); demographic and injury-related data; and measures of physical and psychological health, function, and social support. Of the 96 participants, approximately half of the men and three-fourths of the women consistently reported pain at each point. Phase 1 predictors of the consistency of pain reports for men were being less impaired, being more independent, experiencing more stress, and receiving less social support. Women consistently reporting pain had more stress at Phase 1 than women inconsistently reporting pain. Persons with SCI at risk for chronic pain should be identified and referred to a multidisciplinary pain management program.

Consistency of multi-channel surface EMG recordings: Application in spinal cord injured subjects

We evaluated the consistency of serial polyelectromyographic recordings of altered motor control in spinal cord injured (SCI) individuals. Using 12 pairs of surface electrodes placed over major muscle groups of lower limb and trunk, we examined voluntary and involuntary and phasic and tonic features of motor control using a standardized protocol for brain motor control assessment (BMCA). The surface electromyographic (EMG) data were digitized and analysed on the basis of the root mean square (RMS) envelope of activity, with the exception of phasic tendon tap responses which were evaluated from full bandwidth EMG data. The average amplitudes of responses were calculated. The median correlation of the results from two successive examinations 1-2 weeks apart for all subjects was 0.98. Further analysis was based on ratios of corresponding elements from the two studies. Noise from null responses was suppressed by incorporating a threshold parameter T set to 1 muV(RMS). With this value, pairs of studies in 52 subjects were virtually identical (mean ratio of 1.02 +/- 0.1). Z-scores from two case studies in which pharmacological and physiological interventions changed motor control demonstrated the utility of the procedure. This method offers a reliable and appropriate means of studying altered motor control which is sensitive to changes induced after interventions.

Racial and Ethnic Differences in Community Reintegration in a Community-Based Sample of Adults with Spinal Cord Injury

The relationship of race/ethnicity to community integration and other variables was assessed in a sample of 164 adults who had lived with spinal cord injury for 2 to 47 years. Compared with blacks and Hispanics, whites were older, better educated, better off financially, less likely to have a violent etiology, less severely impaired, more physically independent, better able to access their community, and involved in more productive activities. Hierarchical regression analyses revealed that after controlling for other demographic and injury-related variables, the amount of variance in mobility and productivity accounted for by race/ethnicity was substantially reduced.

Relating clinical and neurophysiological assessment of spasticity by machine learning

Spasticity following spinal cord injury (SCI) is most often assessed clinically using a five-point Ashworth score (AS). A more objective assessment of altered motor control may be achieved by using a comprehensive protocol based on a surface electromyographic (sEMG) activity recorded from thigh and leg muscles. However, the relationship between the clinical and neurophysiological assessments is still unknown. In this paper we employ three different classification methods to investigate this relationship. The experimental results indicate that, if the appropriate set of sEMG features is used, the neurophysiological assessment is related to clinical findings and can be used to predict the AS. A comprehensive sEMG assessment may be proven useful as an objective method of evaluating the effectiveness of various interventions and for follow-up of SCI patients.

Assessment of Spinal Cord Injury Spasticity in Clinical Trials

Spasticity continues to be a significant problem for many people with spinal cord injury, and current therapies are not ideal. Attempts to identify and test new interventions for spasticity are hampered by the lack of a consensus definition of spasticity. Because of the complexity of this disorder, a multidimensional approach to assessment is necessary to understand the scope of functionally important symptoms experienced by patients. This multidimensional assessment should include both objective and subjective assessments of tonic spasticity, phasic spasticity, and involuntary spasms as well as function and quality of life. Measuring only one component of spasticity in a clinical trial is likely to underestimate the benefits of a new intervention.

Stroke during pregnancy

Stroke during pregnancy poses a challenge to the rehabilitation team. A 10-year review of one hospitals records revealed five pregnancies complicated by stroke. The mean age was 29 years (range, 21 to 35 years). Cerebrovascular accidents associated with pregnancy may be due to many causes, with intracranial hemorrhage due to arteriovenous malformation or aneurysm, arterial occlusion due to thrombosis or embolus, venous thrombosis, and vasculitis representing the more common etiologies. Three of the strokes in this study were due to intracranial hemorrhage, and two were due to thrombosis secondary to CNS vasculitis. Two case studies and a review of the literature are presented. Stroke during pregnancy represents a high-risk obstetrical situation that may complicate the rehabilitation process.

Quantification of surface electromyographic recordings for assessment of spasticity

Surface electromyography (sEMG) was used in a group of 100 spinal cord injury (SCI) subjects during a comprehensive protocol to assess the type and severity of their spasticity. Subjects showed the expected range from no spasticity to extreme spasticity with clinical and sEMG criteria. The full range of sEMG responses to passive movement was observed for subjects with an Ashworth score of 3. Plantar stimulation responses, reinforcement maneuver responses and burst activity in relaxation were also evaluated as measures of hyperactivity. sEMGs were more sensitive than were the clinical measures in characterizing the features of spasticity. Use of sEMG data when it does not agree with mechanically derived data is defended. Electrophysiological measures may be usefully applied to provide objective, quantitative data regarding spasticity in SCI subjects and extend the information obtained by clinical examination.