Prevalence of opioid use in adults with spinal cord injury: A systematic review and meta-analysis

OBJECTIVE

To determine the prevalence, reported harms and factors associated with opioid use among adults with spinal cord injury (SCI) living in the community.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Comprehensive literature searches were conducted in PubMed (MEDLINE), EMBASE, CINAHL, Web of Science and Scopus for articles published between 2000 and 2023. Risk of bias was assessed using a prevalence-specific tool. Random-effects meta-analyses were conducted to pool prevalence data for any context of opioids. Sensitivity and subgroup analyses were also performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and the study protocol was registered via Prospero (CRD42022350768).

RESULTS

Of the 4969 potential studies, 38 were included in the review. Fifty-three percent of studies had a low risk of bias, with a high risk of bias in 5% of studies. The pooled prevalence for the 38 studies included in the meta-analysis (total cohort size of 50,473) across any opioid context was 39% (95% confidence interval [CI], 32-47). High heterogeneity was evident, with a prediction interval twice as wide as the 95% CI (prediction interval, 7-84%). Mean or median opioid dose was unreported in 95% of studies. Opioid dose and factors related to opioids were also rarely explored in the SCI populations.

CONCLUSIONS

Results should be interpreted with caution based on the high heterogeneity and imprecise pooled prevalence of opioids. Contextual details including pain, cohort-specific injury characteristics and opioid dosage were inconsistently reported, indicating a clear need for additional studies in a population at greater risk of experiencing opioid-related adverse effects.

Neuroprotective Properties of Antiepileptics: What are the Implications for Psychiatric Disorders?

Since the discovery of the first antiepileptic compound, increasing attention has been paid to antiepileptic drugs (AEDs), and recently, with the understanding of the molecular mechanism underlying cells death, a new interest has revolved around a potential neuroprotective effect of AEDs. While many neurobiological studies in this field have focused on the protection of neurons, growing data are reporting how exposure to AEDs can also affect glial cells and the plastic response underlying recovery; however, demonstrating the neuroprotective abilities of AEDs remains a changeling task. The present work aims to summarize and review the literature available on the neuroprotective properties of the most commonly used AEDs. Results highlighted how further studies should investigate the link between AEDs and neuroprotective properties; while many studies are available on valproate, results for other AEDs are very limited and the majority of the research has been carried out on animal models. Moreover, a better understanding of the biological basis underlying neuro-regenerative defects may pave the way for the investigation of further therapeutic targets and eventually lead to an improvement in the actual treatment strategies.

The Quality of Life of the Patients with Thoracic Ossification of the Ligamentum Flavum after Surgery Using EQ-5D-5L

OBJECTIVE

There is a lack of studies on the quality of life (QoL) after posterior laminectomy in patients with thoracic ossification of the ligamentum flavum (TOLF), and risk factors associated with poor prognosis remain controversial. Therefore, the present study was conducted to illustrate the QoL for TOLF patients after surgery and determine its relationship with their demographic, surgery-related, clinical characteristics and imaging data.

METHODS

One hundred and eighteen patients diagnosed with thoracic myelopathy because of TOLF were enrolled in this retrospective study. They all underwent posterior decompressive laminectomy from August 2010 to January 2022. The QoL was evaluated based on the EQ-5D-5L. Collecting gender, age, number of operations, compressed segments, Frankel grade, complications, body mass index (BMI), symptoms and duration, modified Japanese Orthopaedic Association (mJOA) score (preoperative), follow-up time and type of ossification, increased signal on Sagittal T2-weighted Images (ISST2I), occupancy rate and analyzing by Mann-Whitney U-test, Kruskal-Wallis test, the χ2 -test, and logistic regression tests.

RESULTS

Average follow-up 70.8 months (18-149), the mean age was 59.74 ± 9.81 years and the mean score for the QoL based on the EQ-5D-5 L and visual analogue scale (VAS) score were 0.71 ± 0.28 and 78.88 ± 10.21 at the final follow-up. Moderate and severe problems were found in the pain/discomfort in 22.0% of the patients. These mobility and usual activities numbers were slightly higher (24.6% and 30.4%, respectively). The mean scores for QoL and VAS were significantly higher in patients with mild and moderate neurological impairment, normal BMI, <60 years of age, no dural tears, symptom relief at hospital discharge, unilateral and bilateral ossification on axial CT scan, ≤ 50% spinal canal occupancy on CT and MRI, and none or fuzzy on ISST2I.

CONCLUSION

QoL after posterior laminectomy in TOLF patients is generally satisfactory compared to preoperative levels. Preoperative mJOA score, Age, comorbid diabetes, the major symptom is activity limitation, BMI, ISST2I, Intraoperative dural tears and spinal canal occupancy rate correlate significantly with the corresponding dimensions and are predictive. Age, spinal canal occupancy rate, ISST2I, preoperative mJOA score, BMI are significantly associated with and have predictive value for overall postoperative QoL.

Recovery of Spinal Walking in Paraplegic Dogs Using Physiotherapy and Supportive Devices to Maintain the Standing Position

Paraplegic patients have always been ideal candidates for physiotherapy due to their body's inability to recover on its own. Regardless of the cause that led to the onset of paraplegia (traumatic or degenerative), physiotherapy helps these patients with devices and methods designed to restore the proper functioning of their motility, as well as their quality of life. A total of 60 paraplegic dogs without deep pain in the hindlimbs caused by intervertebral disc extrusion or thoracolumbar fractures underwent physiotherapy sessions: manual therapy (massage), electrostimulation (10-20 min with possible repetition on the same day), ultrasound therapy, laser therapy, hydrotherapy, and assisted gait in supportive devices or on treadmills to stimulate and relearn walking, which was the main focus of the study. To maintain the standing position over time, we developed different devices adapted for each patient depending on the degree of damage and the possible associated pathologies: harnesses, trolleys, straps, exercise rollers, balancing platforms and mattresses, physio balls and rollers for recovery of proprioception. The main objective of our study was to demonstrate that physiotherapy and assisted gait in supportive devices to maintain the standing position may help paraplegic dogs to develop spinal walking. Concurrent pathologies (skin wounds, urinary infections, etc.) were managed concomitantly. Recovery of SW was evaluated by progression in regaining the reflectivity, nociception, gait score, and quality of life. After 125 to 320 physiotherapy sessions (25 to 64 weeks), 35 dogs (58.33%) developed spinal walking and were able to walk without falling or falling only sometimes in the case of a quick look (gait score 11.6 ± 1.57, with 14 considered normal), with a lack of coordination between the thoracic and pelvic limbs or difficulties in turning, especially when changing direction, but with the recovery of the quadrupedal position in less than 30 s. The majority of dogs recovering SW were of small size, with a median weight of 6.83 kg (range: 1.5-15.7), mixed breed (n = 9; 25.71%), Teckel (n = 4; 11.43%), Bichon (n = 5; 14.28%), Pekingese (n = 4; 11.43%), and Caniche (n = 2; 5.71%), while those who did not recover SW were larger in size, 15.59 kg (range: 5.5-45.2), and mixed breed (n = 16; 64%).

Pharmacological management of acute spinal cord injury: a longitudinal multi-cohort observational study

Multiple types and classes of medications are administered in the acute management of traumatic spinal cord injury. Prior clinical studies and evidence from animal models suggest that several of these medications could modify (i.e., enhance or impede) neurological recovery. We aimed to systematically determine the types of medications commonly administered, alone or in combination, in the transition from acute to subacute spinal cord injury. For that purpose, type, class, dosage, timing, and reason for administration were extracted from two large spinal cord injury datasets. Descriptive statistics were used to describe the medications administered within the first 60 days after spinal cord injury. Across 2040 individuals with spinal cord injury, 775 unique medications were administered within the two months after injury. On average, patients enrolled in a clinical trial were administered 9.9 ± 4.9 (range 0-34), 14.3 ± 6.3 (range 1-40), 18.6 ± 8.2 (range 0-58), and 21.5 ± 9.7 (range 0-59) medications within the first 7, 14, 30, and 60 days post-injury, respectively. Those enrolled in an observational study were administered on average 1.7 ± 1.7 (range 0-11), 3.7 ± 3.7 (range 0-24), 8.5 ± 6.3 (range 0-42), and 13.5 ± 8.3 (range 0-52) medications within the first 7, 14, 30, and 60 days post-injury, respectively. Polypharmacy was commonplace (up to 43 medications per day per patient). Approximately 10% of medications were administered acutely as prophylaxis (e.g., against the development of pain or infections). To our knowledge, this was the first time acute pharmacological practices have been comprehensively examined after spinal cord injury. Our study revealed a high degree of polypharmacy in the acute stages of spinal cord injury, raising the potential to impact neurological recovery. All results can be interactively explored on the R_XSCI web site ( https://jutzelec.shinyapps.io/RxSCI/ ) and GitHub repository ( https://github.com/jutzca/Acute-Pharmacological-Treatment-in-SCI/ ).

The predictive value of cortical activity during motor imagery for subacute spinal cord injury-induced neuropathic pain

OBJECTIVE

The aim of this study is to explore whether cortical activation and its lateralization during motor imagery (MI) in subacute spinal cord injury (SCI) are indicative of existing or upcoming central neuropathic pain (CNP).

METHODS

Multichannel electroencephalogram was recorded during MI of both hands in four groups of participants: able-bodied (N = 10), SCI and CNP (N = 11), SCI who developed CNP within 6 months of EEG recording (N = 10), and SCI who remained CNP-free (N = 10). Source activations and its lateralization were derived in four frequency bands in 20 regions spanning sensorimotor cortex and pain matrix.

RESULTS

Statistically significant differences in lateralization were found in the theta band in premotor cortex (upcoming vs existing CNP, p = 0.036), in the alpha band at the insula (healthy vs upcoming CNP, p = 0.012), and in the higher beta band at the somatosensory association cortex (no CNP vs upcoming CNP, p = 0.042). People with upcoming CNP had stronger activation compared to those with no CNP in the higher beta band for MI of both hands.

CONCLUSIONS

Activation intensity and lateralization during MI in pain-related areas might hold a predictive value for CNP.

SIGNIFICANCE

The study increases understanding of the mechanisms underlying transition from asymptomatic to symptomatic early CNP in SCI.

No pain, no strain: Targin® mitigates pain and constipation following spinal cord injury

BACKGROUND

Opioids effectively reduce chronic pain, but present significant side effects including opioid-induced constipation. Oxycodone/naloxone decreases pain and constipation in cancer patients, however its effect on spinal cord injury population remains understudied.

METHODS

We assessed whether oxycodone/naloxone reduces pain, constipation, and severity of autonomic dysreflexia in an individual with spinal cord injury. A 55-year-old male with C5 lesion presented with chief complaint of chronic pain received 5/2.5 mg and 20/10 mg oxycodone/naloxone for 6 and 2 weeks, respectively.

RESULTS

Oxycodone/naloxone improved pain, bowel function, and autonomic dysreflexia severity.

INTERPRETATION

Oxycodone/naloxone was effective in managing chronic pain and constipation in the studied case.

Data management strategy for a collaborative research center

The importance of effective research data management (RDM) strategies to support the generation of Findable, Accessible, Interoperable, and Reusable (FAIR) neuroscience data grows with each advance in data acquisition techniques and research methods. To maximize the impact of diverse research strategies, multidisciplinary, large-scale neuroscience research consortia face a number of unsolved challenges in RDM. While open science principles are largely accepted, it is practically difficult for researchers to prioritize RDM over other pressing demands. The implementation of a coherent, executable RDM plan for consortia spanning animal, human, and clinical studies is becoming increasingly challenging. Here, we present an RDM strategy implemented for the Heidelberg Collaborative Research Consortium. Our consortium combines basic and clinical research in diverse populations (animals and humans) and produces highly heterogeneous and multimodal research data (e.g., neurophysiology, neuroimaging, genetics, behavior). We present a concrete strategy for initiating early-stage RDM and FAIR data generation for large-scale collaborative research consortia, with a focus on sustainable solutions that incentivize incremental RDM while respecting research-specific requirements.

Feasibility of gabapentin as an intervention for neurorecovery after an acute spinal cord injury: Protocol

Introduction

This protocol is describing the first ever prospective, mock-efficacy, dose exploration trial design testing the feasibility of administering gabapentin in the acute setting as an intervention for neurorecovery. Gabapentin is an FDA-approved medication for treating seizures and postherpetic neuralgia and is used broadly off-label for neuropathic pain management for many conditions, including spinal cord injury. Emerging data suggests that when given early after spinal cord injury onset and in low-medium doses, gabapentin may have properties that promote recovery of neurological function. The objective of this trial is to assess the feasibility of conducting an efficacy trial in which gabapentin is started early after injury, is restricted in its dose, and is not used for pain management.

Methods and analysis

Forty-two people aged 18 years or older with any level and any severity of spinal cord injury induced by a trauma will be enrolled, randomized, and have the first dose of study medication by 120 h post-injury onset. Participants will be randomly assigned to one of three groups: 600, 1,800 mg/day gabapentin, or placebo. Study medication will be given for a 90-day duration. Blinded assessments will be obtained at 7 days post-injury (baseline), 30 days post-injury (interim), after the 90-day treatment duration/approximately 3 months post-injury (end of treatment), and at 6 months post-injury (end of study). The key analysis parameters will evaluate feasibility of recruitment of target population, delivery of drug treatment protocol, maintenance of blinding, and retention of participants.

Discussion

Outputs from this trial will inform research and clinical practice on the effects of manipulating gabapentin for non-pain management purposes in the acute setting and will guide the development of a properly powered efficacy trial of gabapentin as an intervention for neurorecovery in spinal cord injury.

Ethics and dissemination

The study was approved by the MetroHealth Institutional Review Board (IRB21-00609) and registered at clinicaltrials.gov prior to enrolling any participants. Dissemination will include peer-reviewed publications, presentations at professional conferences and in the community, and through other healthcare and public venues.

Clinical trial registration

www.ClinicalTrials.gov, identifier: NCT05302999; protocol version 1.1 approved 05/23/2022.

Trial funding

National Institute on Disability, Independent Living and Rehabilitation Research.

Motor Recovery Depends on Timing of Surgery in Patients With Lumbar Disk Herniation

BACKGROUND

Although approximately half of the patients undergoing lumbar disk surgery present with motor deficits, timing of surgery for radicular weakness is largely unclear.

OBJECTIVE

To evaluate the impact of surgical timing on motor recovery in patients with lumbar disk herniation (LDH) and to identify an ideal time window for intervention.

METHODS

In a single-center observational trial, 390 patients with LDH-associated motor deficits were prospectively followed for a minimum of 12 months after nonelective microscopic disk surgery. The duration of motor deficit before surgery was documented. Motor function was graded according to the Medical Research Council (MRC) scale. Statistical analysis of motor recovery applied unbiased recursive partitioning conditional inference tree to determine cutoff times for optimal surgical intervention. The slope of recovery calculated as the change of the MRC grade over time served as the primary outcome.

RESULTS

A preoperative motor deficit of MRC ≤2/5 and the duration of paresis were identified as the most important predictors of recovery ( P < .001). Surgery within 3 days was associated with a better recovery for both severe and moderate/mild deficits ( P = .017 for MRC ≤ 2/5; P < .001 for MRC > 2/5; number needed to treat [NNT] <2). A sensitivity analysis in mild motor deficits indicated a cutoff of 8 days.

CONCLUSION

Timing of surgery is crucial for motor recovery in LDH-associated deficits. Immediate diagnosis, imaging, and referral should be aimed for to allow disk surgery within 3 days in patients with severe and moderate radicular weakness. If functionally disabling, even mild deficits may warrant decompression within a week.

A systematic, concept-based method of developing the exposure measure for drug safety and effectiveness studies

PURPOSE

In drug safety and effectiveness studies based on secondary data, the choice of an appropriate exposure measure for a given outcome can be challenging. Different measures of exposure can yield different estimates of treatment effect and safety. There is a knowledge gap with respect to developing and refining measures of drug exposure, to ensure that the exposure measure addresses the study question and is suitable for statistical analysis.

METHODS

We present a transparent, step-by-step approach to the development of drug exposure measures involving secondary data. This approach would be of interest to students and investigators with initial training in pharmacoepidemiology. We illustrate the approach using a study about Parkinson's disease.

RESULTS

We described the exposure specifications according to the study question. Next, we refined the exposure measure by linking it to knowledge about four major concepts in drug safety and effectiveness studies: drug use patterns, duration, timing, and dose. We then used this knowledge to guide the ultimate choice of exposure measure: time-varying, cumulative 6-month exposure to tamsulosin (a drug used to treat prostate hyperplasia).

CONCLUSIONS

The proposed approach links exposure specifications to four major concepts in drug safety and effectiveness studies. Formulating subject-matter knowledge about these major concepts provides an avenue to develop the rationale and specifications for the exposure measure.

Deep brain stimulation for locomotion in incomplete human spinal cord injury (DBS-SCI): protocol of a prospective one-armed multi-centre study

INTRODUCTION

Spinal cord injury (SCI) is a devastating condition with immediate impact on the individual's health and quality of life. Major functional recovery reaches a plateau 3-4 months after injury despite intensive rehabilitative training. To enhance training efficacy and improve long-term outcomes, the combination of rehabilitation with electrical modulation of the spinal cord and brain has recently aroused scientific interest with encouraging results. The mesencephalic locomotor region (MLR), an evolutionarily conserved brainstem locomotor command and control centre, is considered a promising target for deep brain stimulation (DBS) in patients with SCI. Experiments showed that MLR-DBS can induce locomotion in rats with spinal white matter destructions of >85%.

METHODS AND ANALYSIS

In this prospective one-armed multi-centre study, we investigate the safety, feasibility, and therapeutic efficacy of MLR-DBS to enable and enhance locomotor training in severely affected, subchronic and chronic American Spinal Injury Association Impairment Scale C patients in order to improve functional recovery. Patients undergo an intensive training programme with MLR-DBS while being regularly followed up until 6 months post-implantation. The acquired data of each timepoint are compared with baseline while the primary endpoint is performance in the 6-minute walking test. The clinical trial protocol was written in accordance with the Standard Protocol Items: Recommendations for Interventional Trials checklist.

ETHICS AND DISSEMINATION

This first in-man study investigates the therapeutic potential of MLR-DBS in SCI patients. One patient has already been implanted with electrodes and underwent MLR stimulation during locomotion. Based on the preliminary results which promise safety and feasibility, recruitment of further patients is currently ongoing. Ethical approval has been obtained from the Ethical Committee of the Canton of Zurich (case number BASEC 2016-01104) and Swissmedic (10000316). Results will be published in peer-reviewed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT03053791.

Association of timing of gabapentinoid use with motor recovery after spinal cord injury

OBJECTIVE

To explore the hypothesis that earlier administration of acute gabapentinoids is beneficial to motor recovery after spinal cord injury in humans.

METHODS

This is an observational study using a cohort from the European Multi-Centre Study about Spinal Cord Injury. Patient charts were reviewed to extract information regarding the administration and timing of gabapentinoid anticonvulsants. The primary outcome measure was motor scores, as measured by the International Standards for Neurological Classification of Spinal Cord Injury, collected longitudinally in the first year after injury. Sensory scores (light touch and pinprick) and functional measures (Spinal Cord Independence Measure) were secondary outcomes. Linear mixed effects regression models included a drug-by-time interaction to determine whether exposure to gabapentinoids altered recovery of muscle strength in the first year after injury.

RESULTS

A total of 201 participants were included in the study and had a median age of 46 and baseline motor score of 50. Participants were mostly men (85%) with sensory and motor complete injuries (50%). Seventy individuals (35%) were administered gabapentinoids within the first 30 days after injury, and presented with similar demographics. In the longitudinal model, the administration of gabapentinoids within 30 days after injury was associated with improved motor recovery when compared to those who did not receive gabapentinoids during this time (3.69 additional motor points from 4 to 48 weeks after injury; p = 0.03). This effect size increased as administration occurred earlier after injury (i.e., a benefit of 4.68 points when administered within 5 days).

CONCLUSIONS

This retrospective, observational study provided evidence of the beneficial effect of gabapentinoid anticonvulsants on motor recovery after spinal cord injury. More critically, it highlighted a potential time dependence, suggesting that earlier intervention is associated with better outcomes.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that gabapentinoids improve motor recovery for individuals with acute spinal cord injury.

Ambulation in Dogs With Absent Pain Perception After Acute Thoracolumbar Spinal Cord Injury

Acute thoracolumbar spinal cord injury (SCI) is common in dogs frequently secondary to intervertebral disc herniation. Following severe injury, some dogs never regain sensory function to the pelvic limbs or tail and are designated chronically "deep pain negative." Despite this, a subset of these dogs develop spontaneous motor recovery over time including some that recover sufficient function in their pelvic limbs to walk independently without assistance or weight support. This type of ambulation is commonly known as "spinal walking" and can take up to a year or more to develop. This review provides a comparative overview of locomotion and explores the physiology of locomotor recovery after severe SCI in dogs. We discuss the mechanisms by which post-injury plasticity and coordination between circuitry contained within the spinal cord, peripheral sensory feedback, and residual or recovered supraspinal connections might combine to underpin spinal walking. The clinical characteristics of spinal walking are outlined including what is known about the role of patient or injury features such as lesion location, timeframe post-injury, body size, and spasticity. The relationship between the emergence of spinal walking and electrodiagnostic and magnetic resonance imaging findings are also discussed. Finally, we review possible ways to predict or facilitate recovery of walking in chronically deep pain negative dogs. Improved understanding of the mechanisms of gait generation and plasticity of the surviving tissue after injury might pave the way for further treatment options and enhanced outcomes in severely injured dogs.

Serum albumin as a predictor of neurological recovery after spinal cord injury: a replication study

STUDY DESIGN

This was a secondary analysis on an observational cohort study.

OBJECTIVE

To determine if serum albumin significantly associates with long-term neurological outcome (i.e., 1-year post-injury) in a contemporary cohort of individuals with spinal cord injury.

SETTING

Six rehabilitation centers across the United States.

METHODS

A secondary analysis of neurological outcomes and serum albumin concentrations was performed on data from the Spinal Cord Injury Rehabilitation study. Data was accessed from the Archive of Data on Disability to Enable Policy and research (ADDEP). The primary analysis applied unbiased recursive partitioning to examine the relationship between serum albumin, injury severity, and long-term outcomes. The analysis is accessible via https://rpubs.com/AnhKhoaVo/586028 .

RESULTS

Serum albumin concentration was significantly associated with lower extremity motor scores (LEMS) and American Spinal Injury Association Impairment Scale (AIS) grade at admission to rehabilitation. Serum albumin concentrations alone were also significantly associated with change of LEMS and marked recovery (improvement of at least 2 AIS grades and/or recovery to walking) at 1-year post injury. However, after adjusting for admission to rehabilitation LEMS and AIS grade, serum albumin was not significant.

CONCLUSION

The current study partially confirms our previous observations that serum albumin concentrations are associated with neurological outcome after spinal cord injury. As a crude prognostic biomarker, serum albumin concentration could be useful in cases where injury severity cannot be accurately assessed.

Management Strategies for Spinal Cord Injury Pain Updated for the Twenty-First Century

Traumatic spinal cord injury (SCI) often results in several life-altering impairments, including paralysis, sensory loss, and neurogenic bowel/bladder dysfunction. Some of these SCI-related conditions can be accommodated with compensatory strategies. Perhaps no SCI-associated condition is more troublesome and recalcitrant to the treating physiatrist than chronic neuropathic pain. In addition to the expected challenges in treating any chronic pain condition, treatment of SCI-related pain has the added difficulty of disruption of normal neural pathways that subserve pain transmission and attenuation. This article reviews selected treatment strategies for SCI-associated neuropathic pain.

Beneficial "Pharmaceutical Pleiotropy" of Gabapentinoids in Spinal Cord Injury: A Case for Refining Standard-of-Care

Spinal cord injury results in devastating neurological deficits accompanied by lifelong disability and significant economic burden. While the development of novel compounds or cell-based interventions for spinal cord injury is unquestionably worthwhile, a complementary approach examines current standards of care and the degree to which these can be optimized to benefit long-term neurological function. Numerous classes of drugs, already in use in the acute phase of spinal cord injury, are intriguing because they (1) readily cross the blood-spinal cord barrier to modulate activity in the central nervous system and (2) are administered during a window of time in which neuroprotection, and even some repair, are feasible. Here, we review a rare case of convergent lines of evidence from both preclinical and human studies to support the early administration of a class of drug (ie, gabapentinoids) to both foster motor recovery and reduce the severity of neuropathic pain.

Constructing treatment episodes from concomitant medication logs: a prospective observational study

OBJECTIVES

To describe an approach using concomitant medication log records for the construction of treatment episodes. Concomitant medication log records are routinely collected in clinical studies. Unlike prescription and dispensing records, concomitant medication logs collect utilisation data. Logs can provide information about drug safety and drug repurposing.

DESIGN

A prospective multicentre, multicohort observational study.

SETTING

Twenty-one clinical sites in the USA, Europe, Israel and Australia.

PARTICIPANTS

415 subjects from the de novo cohort of the Parkinson's Progression Markers Initiative.

METHODS

We construct treatment episodes of concomitant medication use. The proposed approach treats temporal gaps as a stoppage of medication and temporal overlaps as simultaneous use or changes in dose. Log records with no temporal gaps were combined into a single treatment episode.

RESULTS

5723 concomitant medication log records were used to construct 3655 treatment episodes for 65 medications. There were 405 temporal gaps representing a stoppage of medication; 985 temporal overlaps representing simultaneous regimens of the same medication and 2696 temporal overlaps representing a change in dose regimen. The median episode duration was 37 months (IQ interval: 11-73 months).

CONCLUSIONS

The proposed approach for constructing treatment episodes offers a method of estimating duration and dose of treatment from concomitant medication log records. The accompanying recommendations guide log data collection to improve their quality for drug safety and drug repurposing.

Skilled reaching deterioration contralateral to cervical hemicontusion in rats is reversed by pregabalin treatment conditional upon its early administration

Introduction

Gabapentinoids are first-line treatments for painful traumatic and nontraumatic central nervous system disorders. Evidence from a large human study suggests that early use of gabapentinoids after spinal cord injury improves motor scores. The underlying mechanism is unknown.

Objectives

We sought to examine the effects of early pregabalin (PGB, a gabapentinoid) treatment on performance in a fine motor task (skilled reaching) after cervical hemicontusion. We also asked whether early PGB administration affected PGB responsiveness later on.

Methods

Rats received C4/5 cervical hemicontusions. Injury severities ranged from 80 to 150 kdyn. We monitored evidence of skin irritation (peri-incisional and elsewhere) and quantified food pellet retrieval using the Montoya staircase test. Behaviours were assessed in rats receiving early (for 3 weeks from injury induction) and/or late (resuming or beginning at week 8) PGB treatment in animals with 150-kdyn injuries.

Results

Contralateral skilled reaching waned in control animals with 150-kdyn injuries. This was prevented in animals, which received early PGB as long as treatment continued. Deterioration of skilled reaching was reversed by later (week 8) PGB only in animals that had received early treatment. Ipsilateral reaching impairment was not improved by PGB. Relief of skin irritation verified early PGB efficacy.

Conclusion

Hemicontusive spinal cord injury produces a contralateral motor phenotype evocative of on-going neuropathic pain. Early PGB preserves sensitivity to subsequent PGB treatment, indicating that motor function is impaired by neuropathic pain and can be improved indirectly by early PGB administration. Direct effects of PGB on motor circuitry cannot be excluded but are not supported by our data.

A Longitudinal Study of the Neurologic Safety of Acute Baclofen Use After Spinal Cord Injury

The objective of our study was to determine whether treatment with baclofen is neurologically safe with respect to exposure during recovery from spinal cord injury. We performed a secondary longitudinal analysis of a cohort of adult patients with traumatic acute spinal cord injury. Cumulative baclofen dose was computed over the first 4 weeks following injury from concomitant medication information from a completed clinical trial. The main outcome measure was neurologic status, which was assessed over 52 weeks with "marked recovery" defined as the conversion to higher sensory and motor function. To complete the drug safety profile, drug toxicity was assessed with assays from standard blood work. Multivariable Cox regression was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs). Of the cohort (n = 651), 18% (n = 115) received baclofen within 4 weeks post injury. Baclofen use was associated with higher rates of marked neurologic recovery, even after adjustment for injury severity (HR = 2.1, 95% CI 1.5-3.0 for high dose vs none). Baclofen exposure was not associated with liver or renal side effects. The use of other medications indicated for spasticity was not associated with neurological outcomes. Overall, this longitudinal analysis provides level 3 evidence on the neurologic safety of baclofen and potential beneficial effects on recovery in the early days after acute traumatic spinal cord injury. The usefulness of concomitant medication files from completed clinical trials is highlighted. We also highlight the importance of incorporating logical patient questions and neurological outcomes into research addressing drug safety.

The Effect of Non-Gabapentinoid Anticonvulsants on Sensorimotor Recovery After Human Spinal Cord Injury

BACKGROUND

Recent observational studies have shown an association between gabapentinoid anticonvulsants and greater motor recovery after spinal cord injury. There is preclinical evidence to suggest that other anticonvulsants, such as sodium channel blockers, may also confer beneficial effects.

PURPOSE

The aim of the current study was to determine if non-gabapentinoid anticonvulsants were associated with neurological recovery after acute, traumatic spinal cord injury.

METHODS

This was an observational cohort study using data from the Sygen clinical trial. The primary outcome was total motor score recovery in the first year after injury. Anticonvulsant use was extracted from concomitant medication records; individuals were classified based on early administration (within 30 days of injury), or late/no administration. Motor recovery was compared using linear mixed effects regression models with a drug-by-time interaction, and adjustment for confounders. A secondary analysis incorporated a propensity score matched cohort.

RESULTS

Of the cohort (n = 570), 6% received anticonvulsants (carbamazepine, phenytoin, clonazepam, phenobarbital, and valproic acid) early after injury. After adjustments for initial injury level and severity, early exposure to non-gabapentinoid anticonvulsants was not associated with motor neurological outcomes (p = 0.38 for all anticonvulsants, p = 0.83 for sodium channel blockers, p = 0.82 in propensity-matched cohort).

CONCLUSION

Non-gabapentinoid anticonvulsant exposure was not associated with greater or lesser neurological recovery. This suggests that these medications, as administered for the acute management of spinal cord injury, do not impact long-term neurological outcomes.

Evaluation of a Clinical Protocol to Assess and Diagnose Neuropathic Pain During Acute Hospital Admission: Results From Traumatic Spinal Cord Injury

OBJECTIVES

A clinical protocol was developed for clinicians to routinely assess and initiate treatment for patients with neuropathic pain (NP) in an acute care setting. The objectives of this study were to: (1) determine the incidence and onset of NP in patients with traumatic spinal cord injury during acute care and (2) describe how the implementation of a clinical protocol impacts the assessment and diagnosis of NP.

MATERIALS AND METHODS

The study was a cohort analysis with a pre-post-test utilizing a historical control. Data were retrospectively collected from a patient registry and charts. Participants were randomly selected in cohort 1 (control) and cohort 2 (NP clinical protocol).

RESULTS

The incidence of NP was 56% without significant difference between the cohorts (P=0.3). Onset of NP was 8 days (SD=14) across the study and >85% of the participants with NP were diagnosed within 2 weeks. Participants with incomplete injuries had a significant earlier onset than participants with complete injuries (6.2±12.8, 10.9±15.8 d; P=0.003). The mean number of days from hospital admission to initial assessment decreased with use of the NP clinical protocol (3.7±5.7 d; P=0.02).

DISCUSSION

This study demonstrates a high incidence and early onset of NP in traumatic spinal cord injury during acute hospital care, with an earlier emergence in participants with incomplete injury. The NP clinical protocol ensured continuous assessment and documentation of NP while decreasing the time to an initial screen, but did not impact diagnosis.

Progression of Neuropathic Pain after Acute Spinal Cord Injury: A Meta-Analysis and Framework for Clinical Trials

The translation of therapeutic interventions to humans with spinal cord injury with the goal of promoting growth and repair in the central nervous system could, inadvertently, drive mechanisms associated with the development of neuropathic pain. A framework is needed to evaluate the probability that a therapeutic intervention for acute spinal cord injury modifies the progression of neuropathic pain. We analyzed a large, longitudinal dataset from the European Multi-Center Study about Spinal Cord Injury (EMSCI) and compared these observations with a previously published Swedish/Danish cohort. A meta-analysis was performed to produce aggregate estimates for the transition period between 1-6 months and the transition period between 1-12 months after injury. A secondary analysis used logistic regression to explore associations between the progression of neuropathic pain and demographics, pain characteristics, and injury characteristics. For overall neuropathic pain, 72% presenting with pain symptoms at one month reported persisting symptoms at six months, and 23% who did not have neuropathic pain at one month later had it develop. From 1-12 months, there was a similar likelihood of pain persisting (69%) and slightly higher rate of pain developing (36%). Characteristics that were significantly associated with the progression of pain included age and sensory and motor preservation. We provide historical benchmarks for estimating the progression of neuropathic pain during the first year after acute SCI. This information will be useful for comparison and evaluating safety during early phase acute spinal cord injury trials.

Open field and a behavior score in PNT model for neuropathic pain in pigs

Background

Rodent models are frequently used in the research of pain and continue to provide valuable data on the mechanisms driving pain, although they are criticized due to limited translational ability to human conditions. Previously we have suggested pigs as a model for development of drugs for neuropathic pain. In this study, we investigate the spontaneous behavior of pigs following peripheral neuritis trauma (PNT)-induced neuropathic pain.

Methods

A computerized monitoring system was used to evaluate the changes in open field test in addition to applying a composite behavior scoring system. The data suggest that the PNT operation did not affect the animal’s ability to walk as the total distance walked by PNT animals was not significantly different from the total distance walked by sham-operated animals. However, PNT animals expressed a significant change in the pattern of walking. This effect was unrelated to the time that the animals spent in the open field. Following treatment with different drugs (morphine, buprenorphine, or gabapentin), the walking pattern of the animals in the open field changed in a drug-specific manner. In addition, the detailed behavior score revealed drug-specific changes following treatment.

Results

Pharmacokinetic analysis of the drug concentration in blood and cerebrospinal fluid correlated with the behavioral analysis.

Conclusion

The data of this study suggest that the open field test together with the detailed behavior score applied in this model are a powerful tool to assess the spontaneous behavior of pigs following PNT-induced neuropathic pain.

Early predictors of developing problematic spasticity following traumatic spinal cord injury: A prospective cohort study

Objective: To identify early predictors and develop reliable, validated prediction models for development of problematic spasticity after traumatic spinal cord injury (SCI).Design: Prospective cohort study of the Rick Hansen Spinal Cord Injury Registry (RHSCIR), retrospective review of inpatient medical charts.Setting: Quaternary trauma center, rehabilitation center, community settings.Participants: Individuals with traumatic SCI between March 1, 2005, and March 31, 2014, prospectively enrolled in the Vancouver site RHSCIR.Interventions: None.Main Outcome Measure: Spasticity limiting function or requiring treatment (problematic spasticity) on the Spinal Cord Injury Health Questionnaire.Results: In 350 patients, variables documented during hospitalization that predicted the development of problematic spasticity up to 5 years post-injury included: initial Glasgow Coma Scale; age at time of injury; admission to rehabilitation center; community discharge anti-spasticity medication prescription, neurological status, Penn Spasm Frequency Scale, and pain interference with quality of life, sleep, activities; greater change in AIS motor scores between admission and discharge. The predictive models had area under the receiver operating characteristic curve of 0.80 (95% CI 0.75, 0.85) in the development set (N = 244) and 0.84 (95% CI 0.74, 0.92) in the validation set (N = 106) for spasticity limiting function and 0.81 (95% CI 0.76, 0.85) in the development set and 0.85 (95% CI 0.77, 0.92) in the validation set for spasticity requiring treatment.Conclusions: Our prediction models provide an early prognosis of risk of developing problematic spasticity after traumatic SCI, which can be used to improve clinical spasticity management and assist research (e.g. risk stratification in interventional trials).

Early Administration of Gabapentinoids Improves Motor Recovery after Human Spinal Cord Injury

The anticonvulsant pregabalin promotes neural regeneration in a mouse model of spinal cord injury (SCI). We have also previously observed that anticonvulsants improve motor outcomes following human SCI. The present study examined the optimal timing and type of anticonvulsants administered in a large, prospective, multi-center, cohort study in acute SCI. Mixed-effects regression techniques were used to model total motor scores at 1, 3, 6, and 12 months post injury. We found that early (not late) administration of anticonvulsants significantly improved motor recovery (6.25 points over 1 year). The beneficial effect of anticonvulsants remained significant after adjustment for differences in 1-month motor scores and injury characteristics. A review of a subset of patients revealed that gabapentinoids were the most frequently administrated anticonvulsant. Together with preclinical findings, intervention with anticonvulsants represents a potential pharmacological strategy to improve motor function after SCI.

Promoting Gait Recovery and Limiting Neuropathic Pain After Spinal Cord Injury

Most persons living with a spinal cord injury experience neuropathic pain in the months following their lesion, at the moment where they receive intensive gait rehabilitation. Based on studies using animal models, it has been proposed that central sensitization in nociceptive pathways (maladaptive plasticity) and plasticity related to motor learning (adaptive plasticity) share common neural mechanisms and compete with each other. This article aims to address the discrepancy between the growing body of basic science literature supporting this hypothesis and the general belief in rehabilitation research that pain and gait rehabilitation represent two independent problems. First, the main findings from basic research showing interactions between nociception and learning in the spinal cord will be summarized, focusing both on evidence demonstrating the impact of nociception on motor learning and of motor learning on central sensitization. Then, the generalizability of these findings in animal models to humans will be discussed. Finally, the way potential interactions between nociception and motor learning are currently taken into account in clinical research in patients with spinal cord injury will be presented. To conclude, recommendations will be proposed to better integrate findings from basic research into future clinical research in persons with spinal cord injury.

The Calcium Channel Subunit Alpha2delta2 Suppresses Axon Regeneration in the Adult CNS

Injuries to the adult CNS often result in permanent disabilities because neurons lose the ability to regenerate their axon during development. Here, whole transcriptome sequencing and bioinformatics analysis followed by gain- and loss-of-function experiments identified Cacna2d2, the gene encoding the Alpha2delta2 subunit of voltage-gated calcium channels (VGCCs), as a developmental switch that limits axon growth and regeneration. Cacna2d2 gene deletion or silencing promoted axon growth in vitro. In vivo, Alpha2delta2 pharmacological blockade through Pregabalin (PGB) administration enhanced axon regeneration in adult mice after spinal cord injury (SCI). As PGB is already an established treatment for a wide range of neurological disorders, our findings suggest that targeting Alpha2delta2 may be a novel treatment strategy to promote structural plasticity and regeneration following CNS trauma.

SCISSOR-Spinal Cord Injury Study on Small molecule-derived Rho inhibition: a clinical study protocol

INTRODUCTION

The approved analgesic and anti-inflammatory drugs ibuprofen and indometacin block the small GTPase RhoA, a key enzyme that impedes axonal sprouting after axonal damage. Inhibition of the Rho pathway in a central nervous system-effective manner requires higher dosages compared with orthodox cyclooxygenase-blocking effects. Preclinical studies on spinal cord injury (SCI) imply improved motor recovery after ibuprofen/indometacin-mediated Rho inhibition. This has been reassessed by a meta-analysis of the underlying experimental evidence, which indicates an overall effect size of 20.2% regarding motor outcome achieved after ibuprofen/indometacin treatment compared with vehicle controls. In addition, ibuprofen/indometacin may also limit sickness behaviour, non-neurogenic systemic inflammatory response syndrome (SIRS), neuropathic pain and heterotopic ossifications after SCI. Consequently, 'small molecule'-mediated Rho inhibition after acute SCI warrants clinical investigation.

METHODS AND ANALYSIS

Protocol of an investigator-initiated clinical open-label pilot trial on high-dose ibuprofen treatment after acute traumatic, motor-complete SCI. A sample of n=12 patients will be enrolled in two cohorts treated with 2400 mg/day ibuprofen for 4 or 12 weeks, respectively. The primary safety end point is an occurrence of serious adverse events, primarily gastroduodenal bleedings. Secondary end points are pharmacokinetics, feasibility and preliminary effects on neurological recovery, neuropathic pain and heterotopic ossifications. The primary safety analysis is based on the incidence of severe gastrointestinal bleedings. Additional analyses will be mainly descriptive and casuistic.

ETHICS AND DISSEMINATION

The clinical trial protocol was approved by the responsible German state Ethics Board, and the Federal Institute for Drugs and Medical Devices. The study complies with the Declaration of Helsinki, the principles of Good Clinical Practice and all further applicable regulations. This safety and pharmacokinetics trial informs the planning of a subsequent randomised controlled trial. Regardless of the result of the primary and secondary outcome assessments, the clinical trial will be reported as a publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02096913; Pre-results.