Sensorimotor Complete Spinal Cord Injury Research Articles

Heart Rate Variability-Based Prediction of Autonomic Dysreflexia After Spinal Cord Injury.

Autonomic dysreflexia (AD) is a common autonomic complication of spinal cord injury (SCI) characterized by a sudden increase is blood pressure triggered by peripheral stimulation, such as bladder distention. Iatrogenic AD events often occur during various medical procedures including urodynamic assessments (UDSs) used to evaluate lower urinary tract (LUT) function in individuals with SCI. To date, there are no established clinical practices that would allow early detection of the development of episodes of AD. Heart rate variability (HRV) is a reliable and non-invasive metric for evaluating autonomic regulation of the cardiovascular system, with demonstrated utility in people with SCI during UDSs. We aim to provide a comprehensive evaluation of cardiovascular function during UDS-induced AD using ultra-short-term HRV analysis and identify changes in cardiovascular dynamics to predict the onset of AD. We assessed cardiovascular data in a total of 24 participants with sensorimotor complete SCI above T6 (17 males, 7 females, median age = 43 [36-50] years) who experienced AD during UDS. We used continuous electrocardiographic recordings to evaluate HRV in 60 sec overlapping windows during filling cystometry. The mean of "normal-to-normal" heartbeats (meanNN), its standard deviation (SDNN), and the root mean square of successive differences (RMSSD) were calculated and used in all subsequent analyses. We found that SDNN and RMSSD diminished during the early phase of bladder filling and sharply increased during AD. Using the lowest point of statistical variability in heart rate (i.e., SDNN), we were able to predict AD events within 240 sec (percentile 25-percentile 75: 172-339 sec) before the first systolic blood pressure peak after AD onset (sensitivity = 0.667; specificity = 0.875). Our results indicated a temporary increase in sympathetic activity during the early phase of bladder filling, which is followed by an increase in parasympathetic outflow to the heart when AD occurs. These findings have significant clinical implications that extend beyond the context of UDS and demonstrate the importance of identifying early changes in HRV in order to accurately predict AD episodes in people living with SCI.

Effect of epidural spinal cord stimulation on female sexual function after spinal cord injury.

Sexual dysfunction is a common consequence for women with spinal cord injury (SCI); however, current treatments are ineffective, especially in the under-prioritized population of women with SCI. This case-series, a secondary analysis of the Epidural Stimulation After Neurologic Damage (E-STAND) clinical trial aimed to investigate the effect of epidural spinal cord stimulation (ESCS) on sexual function and distress in women with SCI. Three females, with chronic, thoracic, sensorimotor complete SCI received daily (24 h/day) tonic ESCS for 13 months. Questionnaires, including the Female Sexual Function Index (FSFI) and Female Sexual Distress Scale (FSDS) were collected monthly. There was a 3.2-point (13.2%) mean increase in total FSFI from baseline (24.5 ± 4.1) to post-intervention (27.8 ± 6.6), with a 4.8-50% improvement in the sub-domains of desire, arousal, orgasm and satisfaction. Sexual distress was reduced by 55%, with a mean decrease of 12 points (55.4%) from baseline (21.7 ± 17.2) to post-intervention (9.7 ± 10.8). There was a clinically meaningful change of 14 points in the International Standards for Neurological Classification of Spinal Cord Injury total sensory score from baseline (102 ± 10.5) to post-intervention (116 ± 17.4), without aggravating dyspareunia. ESCS is a promising treatment for sexual dysfunction and distress in women with severe SCI. Developing therapeutic interventions for sexual function is one of the most meaningful recovery targets for people with SCI. Additional large-scale investigations are needed to understand the long-term safety and feasibility of ESCS as a viable therapy for sexual dysfunction. Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT03026816, NCT03026816.

Training with noninvasive brain–machine interface, tactile feedback, and locomotion to enhance neurological recovery in individuals with complete paraplegia: a randomized pilot study

In recent years, our group and others have reported multiple cases of consistent neurological recovery in people with spinal cord injury (SCI) following a protocol that integrates locomotion training with brain machine interfaces (BMI). The primary objective of this pilot study was to compare the neurological outcomes (motor, tactile, nociception, proprioception, and vibration) in both an intensive assisted locomotion training (LOC) and a neurorehabilitation protocol integrating assisted locomotion with a noninvasive brain–machine interface (L + BMI), virtual reality, and tactile feedback. We also investigated whether individuals with chronic-complete SCI could learn to perform leg motor imagery. We ran a parallel two-arm randomized pilot study; the experiments took place in São Paulo, Brazil. Eight adults sensorimotor-complete (AIS A) (all male) with chronic (> 6 months) traumatic spinal SCI participated in the protocol that was organized in two blocks of 14 weeks of training and an 8-week follow-up. The participants were allocated to either the LOC group (n = 4) or L + BMI group (n = 4) using block randomization (blinded outcome assessment). We show three important results: (i) locomotion training alone can induce some level of neurological recovery in sensorimotor-complete SCI, and (ii) the recovery rate is enhanced when such locomotion training is associated with BMI and tactile feedback (∆Mean Lower Extremity Motor score improvement for LOC = + 2.5, L + B = + 3.5; ∆Pinprick score: LOC = + 3.75, L + B = + 4.75 and ∆Tactile score LOC = + 4.75, L + B = + 9.5). (iii) Furthermore, we report that the BMI classifier accuracy was significantly above the chance level for all participants in L + B group. Our study shows potential for sensory and motor improvement in individuals with chronic complete SCI following a protocol with BMIs and locomotion therapy. We report no dropouts nor adverse events in both subgroups participating in the study, opening the possibility for a more definitive clinical trial with a larger cohort of people with SCI.Trial registration: http://www.ensaiosclinicos.gov.br/ identifier RBR-2pb8gq.

Alterations of Spinal Epidural Stimulation-Enabled Stepping by Descending Intentional Motor Commands and Proprioceptive Inputs in Humans With Spinal Cord Injury.

Background: Regaining control of movement following a spinal cord injury (SCI) requires utilization and/or functional reorganization of residual descending, and likely ascending, supraspinal sensorimotor pathways, which may be facilitated via task-specific training through body weight supported treadmill (BWST) training. Recently, epidural electrical stimulation (ES) combined with task-specific training demonstrated independence of standing and stepping functions in individuals with clinically complete SCI. The restoration of these functions may be dependent upon variables such as manipulation of proprioceptive input, ES parameter adjustments, and participant intent during step training. However, the impact of each variable on the degree of independence achieved during BWST stepping remains unknown.Objective: To describe the effects of descending intentional commands and proprioceptive inputs, specifically body weight support (BWS), on lower extremity motor activity and vertical ground reaction forces (vGRF) during ES-enabled BWST stepping in humans with chronic sensorimotor complete SCI. Furthermore, we describe perceived changes in the level of assistance provided by clinicians when intent and BWS are modified.Methods: Two individuals with chronic, mid thoracic, clinically complete SCI, enrolled in an IRB and FDA (IDE G150167) approved clinical trial. A 16-contact electrode array was implanted in the epidural space between the T11-L1 vertebral regions. Lower extremity motor output and vertical ground reaction forces were obtained during clinician-assisted ES-enabled treadmill stepping with BWS. Consecutive steps were achieved during various experimentally-controlled conditions, including intentional participation and varied BWS (60% and 20%) while ES parameters remain unchanged.Results: During ES-enabled BWST stepping, the knee extensors exhibited an increase in motor activation during trials in which stepping was passive compared to active or during trials in which 60% BWS was provided compared to 20% BWS. As a result of this increased motor activation, perceived clinician assistance increased during the transition from stance to swing. Intentional participation and 20% BWS resulted in timely and purposeful activation of the lower extremities muscles, which improved independence and decreased clinician assistance.Conclusion: Maximizing participant intention and optimizing proprioceptive inputs through BWS during ES-enabled BWST stepping may facilitate greater independence during BWST stepping for individuals with clinically complete SCI.Clinical Trial Registration: ClinicalTrials.gov identifier: NCT02592668.

Prevalence of discomplete sensorimotor spinal cord injury as evidenced by neurophysiological methods: A cross-sectional study.

ObjectivesTo assess the prevalence of residual trans-lesion connectivity in persons with chronic clinically complete spinal cord injury (discompleteness) by neurophysiological methods.ParticipantsA total of 23 adults with chronic sensorimotor complete spinal cord injury, identified through regional registries the regional spinal cord registry of Östergötland, Sweden.MethodsDiagnosis of clinically complete spinal cord injury was verified by standardized neurological examination. Then, a neurophysiological examination was performed, comprising electroneurography, electromyography, sympathetic skin response and evoked potentials (sensory, laser and motor). Based on this assessment, a composite outcome measure, indicating either strong, possible or no evidence of discomplete spinal cord injury, was formed.ResultsStrong neurophysiological evidence of discomplete spinal cord injury was found in 17% (4/23) of participants. If also accepting “possible evidence”, the discomplete group comprised 39% (9/23). The remaining 61% showed no neurophysiological evidence of discompleteness. However, if also counting reports of subjective sensation elicited during neurophysiological testing in the absence of objective findings, 52% (12/23) showed indication of discomplete spinal cord injury.CONCLUSIONEvidence of discomplete spinal cord injury can be demonstrated using standard neurophysiological techniques in a substantial subset of individuals with clinically complete spinal cord injury. This study adds to the evidence base indicating the potential of various modes of cross-lesional sensorimotor functional restoration in some cases of chronic clinically complete spinal cord injury.LAY ABSTRACTSpinal cord injuries are usually classed as complete or incomplete. A complete injury implies that no residual function exists below the neurological level of injury. This status is determined by standardized neurological examination and is thought to correlate with spinal cord function in each individual with spinal cord injuries. However, studies have indicated that, in some people with complete spinal cord injury, there may be residual function that is not detected by such testing. The aim of the current study was to examine whether residual function, which is not detected by such testing, exists, and, if so, how common it is among people with complete spinal cord injuries (based on clinical testing) in a chronic stage (>2 years since injury). A battery of neurophysiological tests was used. Signs of “subclinical” residual function were found in 17–39% of 23 participants. This finding may lead to improvements in rehabilitative outcomes for people with complete spinal cord injury.

Natural history of neurological improvement following complete (AIS A) thoracic spinal cord injury across three registries to guide acute clinical trial design and interpretation

Study designRetrospective, longitudinal analysis of motor and sensory outcomes following thoracic (T2–T12) sensorimotor complete spinal cord injury (SCI) in selected patients enrolled into three SCI) registries.ObjectivesTo establish a modern-day international benchmark for neurological recovery following traumatic complete thoracic sensorimotor SCI in a population similar to those enrolled in acute clinical trials.SettingAffiliates of the North American Clinical Trial Network (NACTN), European Multicenter Study about Spinal Cord Injury (EMSCI), and the Spinal Cord Injury Model Systems (SCIMS).MethodsOnly traumatic thoracic injured patients between 2006 and 2016 meeting commonly used clinical trial inclusion/exclusion criteria such as: age 16–70, T2–T12 neurological level of injury (NLI), ASIA Impairment Scale (AIS) A, non-penetrating injury, acute neurological exam within 7 days of injury, and follow-up neurological exam at least ~ 6 months post injury, were included in this analysis. International Standards for Neurological Classification of Spinal Cord injury outcomes including AIS conversion rate, NLI, and sensory and motor scores/levels were compiled.ResultsA total of 170 patients were included from the three registries: 12 from NACTN, 64 from EMSCI, and 94 from SCIMS. AIS conversion rates at approximately 6 months post injury varied from 16.7% to 23.4% (21.1% weighted average). Improved conversion rates were observed in all registries for low thoracic (T10–T12) injuries when compared with high/mid thoracic (T2–T9) injuries. The NLI was generally stable and lower extremity motor score (LEMS) improvement was uncommon and usually limited to low thoracic injuries only.ConclusionsThis study presents the aggregation of selected multinational natural history recovery data in thoracic AIS A patients from three SCI registries and demonstrates comparable minimal improvement of ISNCSCI-scored motor and sensory function following these injuries, whereas conversions to higher AIS grades occur at a frequency of ~20%. These data inform the development of future clinical trial protocols in this important patient population for the interpretation of the safety and potential clinical benefit of new therapies, and the potential applicability in a multinational setting.SponsorshipInVivo Therapeutics.

3T MR-defecography—A feasibility study in sensorimotor complete spinal cord injured patients with neurogenic bowel dysfunction

IntroductionTo investigate whether MR-defecography can be employed in sensorimotor complete spinal cord injury (SCI) subjects as a potential diagnostic tool to detect defecational disorders associated with neurogenic bowel dysfunction (NBD) using standard parameters for obstructed defecation. Material and methodsIn a prospective single centre clinical trial, we developed MR-defecography in traumatic sensorimotor complete paraplegic SCI patients with upper motoneuron type injury (neurological level of injury T1 to T10) using a conventional 3T scanner. Defecation was successfully induced by eliciting the defecational reflex after rectal filling with ultrasonic gel, application of two lecicarbon suppositories and digital rectal stimulation. Examination was performed with patients in left lateral decubitus position using T2-weighted turbo spin echo sequence in the sagittal plane at rest (TE 89ms, TR 3220ms, FOV 300mm, matrix 512×512, ST 4mm) and ultrafast-T2-weighted-sequence in the sagittal plane with repeating measurements (TE 1.54ms, TR 3.51ms, FOV 400mm, matrix 256×256, ST 6mm). Changes of anorectal angle (ARA), anorectal descent (ARJ) and pelvic floor weakness were documented and measured data was compared to reference values of asymptomatic non-SCI subjects in the literature to assess feasibility. ResultsMR-defecography provides evaluable imaging sequences of the induced evacuation phase in SCI patients. Measurement results for ARA, ARJ, hiatal width (H-line) and hiatal descent (M-line) deviate significantly from reference values in the literature in asymptomatic subjects without SCI. The overall mean values in our study for SCI patients were: ARA (rest) 127.3°, ARA (evacuation) 137.6°, ARJ (rest) 2.4cm, ARJ (evacuation) 4.0cm, H-line (rest) 7.6cm, H-line (evacuation) 8.1cm, M-line (rest) 2.6cm, M-line (evacuation) 4.2cm. ConclusionsMR-defecography is feasible in sensorimotor complete SCI patients. Individual MR-defecography findings may help to determine specific therapeutical options for respective patients suffering from severe NBD.

Relationship Between Motor Recovery and Independence After Sensorimotor-Complete Cervical Spinal Cord Injury

Background. For therapeutics directed to the injured spinal cord, a change in neurological impairment has been proposed as a relevant acute clinical study end point. However, changes in neurological function, even if statistically significant, may not be associated with a functional impact, such as a meaningful improvement in items within the self-care subscore of the Spinal Cord Independence Measure (SCIM). Objective. The authors examined the functional significance associated with spontaneously recovering upper-extremity motor function after sensorimotor-complete cervical spinal cord injury (SCI). Methods. Using the European Multi-center Study about Spinal Cord Injury (EMSCI) data set, a retrospective analysis was undertaken of individuals with cervical sensorimotor-complete SCI (initial motor level, C4-C7). Specifically, changes in upper-extremity motor score (UEMS), motor level, and SCIM (total and self-care subscore) were assessed between approximately 1 and 48 weeks after injury (n = 74). Results. The initial motor level did not significantly influence the total UEMS recovered or number of motor levels recovered. SCIM self-care subscore recovery was significantly greater for those individuals regaining 2 motor levels compared with those recovering only 1 or no motor levels. However, the recovery in the SCIM self-care subscore was not significantly different between individuals recovering only 1 motor level and those individuals who showed no motor-level improvement. Conclusions. A 2 motor-level improvement indicates a clinically meaningful change and might be considered a primary outcome in acute and subacute interventional trials enrolling individuals with cervical sensorimotor-complete SCI.

Outcome Measures for Acute/Subacute Cervical Sensorimotor Complete (AIS-A) Spinal Cord Injury During a Phase 2 Clinical Trial.

Effective treatment after cervical spinal cord injury (SCI) is imperative as so many activities of daily living (ADLs) are dependent on functional recovery of arm and hand actions. We focus on defining and comparing neurological and functional endpoints that might be used during acute or subacute Phase 2 clinical trials involving subjects with cervical sensorimotor complete SCI (ASIA Impairment Scale [AIS-A]). For the purposes of this review, the trial would examine the effects of a pharmaceutical small molecule, drug, biologic, or cell transplant on spinal tissue. Thus, neurological improvement is the intended consequence and is most directly measured by assessing neurological impairment (eg, motor aspects of the International Standards Neurological Classification of Spinal Cord Injury [ISNCSCI]). However, changes in neurological function, even if statistically significant, may not be associated with a clear functional impact (ie, a meaningful improvement in individual activity, such as independent self-care ADLs). The challenge is to measure improvement as precisely as possible (change in impairment), but to define a clinically meaningful response in the context of functional improvement (impact on activity limitations). The principal comparisons focused on elements of the ISNCSCI assessment, including upper extremity motor score and motor level. Personal activity capabilities were also examined at various time points. The data suggest that an improvement of 2 or more motor levels after cervical sensorimotor complete SCI may be a clinically meaningful endpoint threshold that could be used for acute and subacute Phase 2 trials with subjects having sensorimotor complete cervical SCI.

Characterization of neurological recovery following traumatic sensorimotor complete thoracic spinal cord injury

Retrospective, longitudinal analysis of sensory, motor and functional outcomes from individuals with thoracic (T2-T12) sensorimotor complete spinal cord injury (SCI). To characterize neurological changes over the first year after traumatic thoracic sensorimotor complete SCI. A dataset of 399 thoracic complete SCI subjects from the European Multi-center study about SCI (EMSCI) was examined for neurological level, sensory levels and sensory scores (pin-prick and light touch), lower extremity motor score (LEMS), ASIA Impairment Scale (AIS) grade, and Spinal Cord Independence Measure (SCIM) over the first year after SCI. AIS grade conversions were limited. Sensory scores exhibited minimal mean change, but high variability in both rostral and caudal directions. Pin-prick and light touch sensory levels, as well as neurological level, exhibited minor changes (improvement or deterioration), but most subjects remained within one segment of their initial injury level after 1 year. Recovery of LEMS occurred predominantly in subjects with low thoracic SCI. The sensory zone of partial preservation (ZPP) had no prognostic value for subsequent recovery of sensory levels or LEMS. However, after mid or low thoracic SCI, ≥3 segments of sensory ZPP correlated with an increased likelihood for AIS grade conversion. The data suggest that a sustained deterioration of three or more thoracic sensory levels or loss of upper extremity motor function are rare events and may be useful for tracking the safety of a therapeutic intervention in early phase acute SCI clinical trials, if a significant proportion of study subjects exhibit such an ascent.

Extent of spontaneous motor recovery after traumatic cervical sensorimotor complete spinal cord injury

Retrospective, longitudinal analysis of motor recovery data from individuals with cervical (C4-C7) sensorimotor complete spinal cord injury (SCI) according to the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). To analyze the extent and patterns of spontaneous motor recovery over the first year after traumatic cervical sensorimotor complete SCI. Datasets from the European multicenter study about SCI (EMSCI) and the Sygen randomized clinical trial were examined for conversion of American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade, change in upper extremity motor score (UEMS) or motor level, as well as relationships between these measures. There were no overall differences between the EMSCI and Sygen datasets in motor recovery patterns. After 1 year, up to 70% of subjects spontaneously recovered at least one motor level, but only 30% recovered two or more motor levels, with lesser values at intermediate time points. AIS grade conversion did not significantly influence motor level changes. At 1 year, the average spontaneous improvement in bilateral UEMS was 10-11 motor points. There was only moderate relationship between a change in UEMS and a change in cervical motor level (r(2)=0.30, P<0.05). Regardless of initial cervical motor level, most individuals recover a similar number of motor points or motor levels. Careful tracking of cervical motor recovery outcomes may provide the necessary sensitivity and accuracy to reliably detect a subtle, but meaningful treatment effect after sensorimotor complete cervical SCI. The distribution of the UEMS change may be more important functionally than the total UEMS recovered.