Patient engagement in designing, conducting, and disseminating clinical pain research: IMMPACT recommended considerations

ABSTRACT

In the traditional clinical research model, patients are typically involved only as participants. However, there has been a shift in recent years highlighting the value and contributions that patients bring as members of the research team, across the clinical research lifecycle. It is becoming increasingly evident that to develop research that is both meaningful to people who have the targeted condition and is feasible, there are important benefits of involving patients in the planning, conduct, and dissemination of research from its earliest stages. In fact, research funders and regulatory agencies are now explicitly encouraging, and sometimes requiring, that patients are engaged as partners in research. Although this approach has become commonplace in some fields of clinical research, it remains the exception in clinical pain research. As such, the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials convened a meeting with patient partners and international representatives from academia, patient advocacy groups, government regulatory agencies, research funding organizations, academic journals, and the biopharmaceutical industry to develop consensus recommendations for advancing patient engagement in all stages of clinical pain research in an effective and purposeful manner. This article summarizes the results of this meeting and offers considerations for meaningful and authentic engagement of patient partners in clinical pain research, including recommendations for representation, timing, continuous engagement, measurement, reporting, and research dissemination.

A Comparison of Veterans with Problematic Opioid Use Identified through Natural Language Processing of Clinical Notes versus Using Diagnostic Codes

Opioid use disorder is known to be under-coded as a diagnosis, yet problematic opioid use can be documented in clinical notes, which are included in electronic health records. We sought to identify problematic opioid use from a full range of clinical notes and compare the demographic and clinical characteristics of patients identified as having problematic opioid use exclusively in clinical notes to patients documented through ICD opioid use disorder diagnostic codes. We developed and applied a natural language processing (NLP) tool that combines rule-based pattern analysis and a trained support vector machine to the clinical notes of a patient cohort (n = 222,371) from two Veteran Affairs service regions to identify patients with problematic opioid use. We also used a set of ICD diagnostic codes to identify patients with opioid use disorder from the same cohort. The NLP tool achieved 96.6% specificity, 90.4% precision/PPV, 88.4% sensitivity/recall, and 94.4% accuracy on unseen test data. NLP exclusively identified 57,331 patients; 6997 patients had positive ICD code identifications. Patients exclusively identified through NLP were more likely to be women. Those identified through ICD codes were more likely to be male, younger, have concurrent benzodiazepine prescriptions, more comorbidities, and more care encounters, and were less likely to be married. Patients in both these groups had substantially elevated comorbidity levels compared with patients not documented through either method as experiencing problematic opioid use. Clinicians may be reluctant to code for opioid use disorder. It is therefore incumbent on the healthcare team to search for documentation of opioid concerns within clinical notes.

Diagnosis and Treatment of Low Back Pain: Synopsis of the 2021 US Department of Veterans Affairs and US Department of Defense Clinical Practice Guideline

ABSTRACT

Low back pain is a significant issue in the US Department of Veterans Affairs and Department of Defense populations as well as the general US population at large. This type of pain can be distressing to those who experience its effects, leading patients to seek relief of their symptoms. In 2022, leadership within the US Department of Veterans Affairs and US Department of Defense approved a joint clinical practice guideline for the management of low back pain. The guideline provides evidence-based recommendations for assessing and managing low back pain. Development of the guideline included a systematic evidence review, which was guided by 12 key questions. A multidisciplinary team, which included clinical stakeholders, reviewed the evidence that was retrieved and developed 39 recommendations using the Grading of Recommendations Assessment, Development, and Evaluation system. The scope of the clinical practice guideline is broad; however, the authors have focused on key recommendations that are important for clinicians in the evaluation and nonoperative treatment of low back pain, including pharmacologic therapies and both noninvasive and invasive nonpharmacologic treatments.

A national study of clinical discussions about cannabis use among Veteran patients prescribed opioids

BACKGROUND

The Veterans Health Administration tracks urine drug tests (UDTs) among patients on long-term opioid therapy (LTOT) and recommends discussing the health effects of cannabis use.

OBJECTIVE

To determine the occurrence of cannabis-related discussions between providers and patients on LTOT during six months following UDT positive for cannabis, and examine factors associated with documenting cannabis use.

DESIGN

We identified patients prescribed LTOT with a UDT positive for cannabis in 2019. We developed a text-processing tool to extract discussions around cannabis use from their charts.

SUBJECTS

Twelve thousand seventy patients were included. Chart review was conducted on a random sample of 1,946 patients.

MAIN MEASURES

The presence of a cannabis term in the chart suggesting documented cannabis use or cannabis-related discussions. Content of those discussions was extracted in a subset of patients. Logistic regression was used to examine the association between patient factors, including state of residence legal status, with documentation of cannabis use.

KEY RESULTS

Among the 12,070 patients, 65.8% (N = 7,948) had a cannabis term, whereas 34.1% (N = 4,122) of patients lacked a cannabis term, suggesting that no documentation of cannabis use or discussion between provider and patient took place. Among the subset of patients who had a discussion documented, 47% related to cannabis use for medical reasons, 35% related to a discussion of VA policy or legal issues, and 17% related to a discussion specific to medical risks or harm reduction strategies. In adjusted analyses, residents of states with legalized recreational cannabis were less likely to have any cannabis-related discussion compared to patients in non-legal states [OR 0.73, 95% CI 0.64-0.82].

CONCLUSIONS

One-third of LTOT patients did not have documentation of cannabis use in the chart in the 6 months following a positive UDT for cannabis. Discussions related to the medical risks of cannabis use or harm reduction strategies were uncommon.

National review of acute pain service utilization, models of care, and clinical practices within the Veterans Health Administration

INTRODUCTION

The Veterans Health Administration (VHA) is the largest healthcare network in the USA and has been a national leader in opioid safety for acute pain management. However, detailed information on the availability and characteristics of acute pain services within its facilities is lacking. We designed this project to assess the current state of acute pain services within the VHA.

METHODS

A 50-question electronic survey developed by the VHA national acute pain medicine committee was emailed to anesthesiology service chiefs at 140 VHA surgical facilities within the USA. Data collected were analyzed by facility complexity level and service characteristics.

RESULTS

Of the 140 VHA surgical facilities contacted, 84 (60%) completed the survey. Thirty-nine (46%) responding facilities had an acute pain service. The presence of an acute pain service was associated with higher facility complexity level designation. The most common staffing model was 2.0 full-time equivalents, which typically included at least one physician. Services performed most by formal acute pain programs included peripheral nerve catheters, inpatient consult services, and ward ketamine infusions.

CONCLUSIONS

Despite widespread efforts to promote opioid safety and improve pain management, the availability of dedicated acute pain services within the VHA is not universal. Higher complexity programs are more likely to have acute pain services, which may reflect differential resource distribution, but the barriers to implementation have not yet been fully explored.

Changes in opioid prescribing in veterans with headache during the COVID-19 pandemic: A regression discontinuity in time analysis

OBJECTIVE

To determine changes in opioid prescribing among veterans with headaches during the coronavirus disease of 2019 (COVID-19) pandemic by comparing the stay-at-home phase (March 15 to May 30, 2020) and the reopening phase (May 31 to December 31, 2020).

BACKGROUND

Opioid prescribing for chronic pain has declined substantially since 2016; however, changes in opioid prescribing during the COVID-19 pandemic among veterans with headaches remain unknown.

METHODS

This retrospective cohort study utilized regression discontinuity in time and difference-in-differences design to analyze veterans aged ≥18 years with a previous diagnosis of headache disorders and an outpatient visit to the Veterans Health Administration (VHA) during the study period. We measured the weekly number of opioid prescriptions, the number of days supplied, the daily dose in morphine milligram equivalents (MMEs), and the number of prescriptions with ≥50 morphine equivalent daily doses (MEDD).

RESULTS

A total of 81,376 veterans were analyzed with 589,950 opioid prescriptions. The mean (SD) age was 51.6 (13.5) years, 57,242 (70.3%) were male, and 53,464 (65.7%) were White. During the pre-pandemic period, 323.6 opioid prescriptions (interquartile range 292.1-325.8) were dispensed weekly, with an median (IQR) of 24.1 (24.0-24.4) days supplied and 31.8 (31.2-32.5) MMEs. Transition to stay-at-home was associated with a 7.7% decrease in the number of prescriptions (incidence rate ratio [IRR] 1.077, 95% confidence interval [CI] 0.866-0.984) and a 9.8% increase in days supplied (IRR 1.098, 95% CI 1.078-1.119). Similar trends were observed during the reopening period. Subgroup analysis among veterans on long-term opioid therapy also revealed 1.7% and 1.4% increases in days supplied during the stay-at-home (IRR 1.017, 95% CI 1.009-1.025) and reopening phase (IRR 1.014, 95% CI 1.007-1.021); however, changes in the total number of prescriptions, MME/day, or the number of prescriptions >50 MEDD were insignificant.

CONCLUSION

Prescription opioid access was maintained for veterans within VHA during the pandemic. The de-escalation of opioid prescribing observed prior to the pandemic was not seen in our study.

Research objectives and general considerations for pragmatic clinical trials of pain treatments: IMMPACT statement

ABSTRACT

Many questions regarding the clinical management of people experiencing pain and related health policy decision-making may best be answered by pragmatic controlled trials. To generate clinically relevant and widely applicable findings, such trials aim to reproduce elements of routine clinical care or are embedded within clinical workflows. In contrast with traditional efficacy trials, pragmatic trials are intended to address a broader set of external validity questions critical for stakeholders (clinicians, healthcare leaders, policymakers, insurers, and patients) in considering the adoption and use of evidence-based treatments in daily clinical care. This article summarizes methodological considerations for pragmatic trials, mainly concerning methods of fundamental importance to the internal validity of trials. The relationship between these methods and common pragmatic trials methods and goals is considered, recognizing that the resulting trial designs are highly dependent on the specific research question under investigation. The basis of this statement was an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) systematic review of methods and a consensus meeting. The meeting was organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership. The consensus process was informed by expert presentations, panel and consensus discussions, and a preparatory systematic review. In the context of pragmatic trials of pain treatments, we present fundamental considerations for the planning phase of pragmatic trials, including the specification of trial objectives, the selection of adequate designs, and methods to enhance internal validity while maintaining the ability to answer pragmatic research questions.

A national population-based study of cannabis use and correlates among U.S. veterans prescribed opioids in primary care

BACKGROUND

Cannabis is marketed as a treatment for pain. There is limited data on the prevalence of cannabis use and its correlates among Veterans prescribed opioids.

OBJECTIVE

To examine the prevalence and correlates of cannabis use among Veterans prescribed opioids.

DESIGN

Cross-sectional study.

PARTICIPANTS

Veterans with a urine drug test (UDT) from Primary Care 2014-2018, in 50 states, Washington, D.C., and Puerto Rico. A total of 1,182,779 patients were identified with an opioid prescription within 90 days prior to UDT.

MAIN MEASURES

Annual prevalence of cannabis positive UDT by state. We used multivariable logistic regression to assess associations of demographic factors, mental health conditions, substance use disorders, and pain diagnoses with cannabis positive UDT.

RESULTS

Annual prevalence of cannabis positive UDT ranged from 8.5% to 9.7% during the study period, and in 2018 was 18.15% in Washington, D.C. and 10 states with legalized medical and recreational cannabis, 6.1% in Puerto Rico and 25 states with legalized medical cannabis, and 4.5% in non-legal states. Younger age, male sex, being unmarried, and marginal housing were associated with use (p < 0.001). Post-traumatic stress disorder (adjusted odds ratio [AOR] 1.17; 95% confidence interval [CI] 1.13-1.22, p < 0.001), opioid use disorder (AOR 1.14; CI 1.07-1.22, p < 0.001), alcohol use disorder or positive AUDIT-C (AOR 1.34; 95% CI 1.28-1.39, p < 0.001), smoking (AOR 2.58; 95% CI 2.49-2.66, p < 0.001), and other drug use disorders (AOR 1.15; 95% CI 1.03-1.29, p = 0.02) were associated with cannabis use. Positive UDT for amphetamines AOR 1.41; 95% CI 1.26-1.58, p < 0.001), benzodiazepines (AOR 1.41; 95% CI 1.31-1.51, p < 0.001) and cocaine (AOR 2.04; 95% CI 1.75-2.36, p < 0.001) were associated with cannabis positive UDT.

CONCLUSIONS

Cannabis use among Veterans prescribed opioids varied by state and by legalization status. Veterans with PTSD and substance use disorders were more likely to have cannabis positive UDT. Opioid-prescribed Veterans using cannabis may benefit from screening for these conditions, referral to treatment, and attention to opioid safety.

The Use of Opioids in the Management of Chronic Pain: Synopsis of the 2022 Updated U.S. Department of Veterans Affairs and U.S. Department of Defense Clinical Practice Guideline

DESCRIPTION

In May 2022, leadership within the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) approved a joint clinical practice guideline for the use of opioids when managing chronic pain. This synopsis summarizes the recommendations that the authors believe are the most important to highlight.

METHODS

In December 2020, the VA/DoD Evidence-Based Practice Work Group assembled a team to update the 2017 VA/DoD Clinical Practice Guideline for Opioid Therapy for Chronic Pain. The guideline development team included clinical stakeholders and conformed to the National Academy of Medicine's tenets for trustworthy clinical practice guidelines. The guideline team developed key questions to guide a systematic evidence review that was done by an independent third party and distilled 20 recommendations for care using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. The guideline team also created 3 one-page algorithms to help guide clinical decision making. This synopsis presents the recommendations and highlights selected recommendations on the basis of clinical relevance.

RECOMMENDATIONS

This guideline is intended for clinicians who may be considering opioid therapy to manage patients with chronic pain. This synopsis reviews updated recommendations for the initiation and continuation of opioid therapy; dose, duration, and taper of opioids; screening, assessment, and evaluation; and risk mitigation. New additions are highlighted, including recommendations about the use of buprenorphine instead of full agonist opioids; assessing for behavioral health conditions and factors associated with higher risk for harm, such as pain catastrophizing; and the use of pain and opioid education to reduce the risk for prolonged opioid use for postsurgical pain.

Opioid use and opioid use disorder in mono and dual-system users of veteran affairs medical centers

Introduction

Efforts to achieve opioid guideline concordant care may be undermined when patients access multiple opioid prescription sources. Limited data are available on the impact of dual-system sources of care on receipt of opioid medications.

Objective

We examined whether dual-system use was associated with increased rates of new opioid prescriptions, continued opioid prescriptions and diagnoses of opioid use disorder (OUD). We hypothesized that dual-system use would be associated with increased odds for each outcome.

Methods

This retrospective cohort study was conducted using Veterans Administration (VA) data from two facilities from 2015 to 2019, and included active patients, defined as Veterans who had at least one encounter in a calendar year (2015-2019). Dual-system use was defined as receipt of VA care as well as VA payment for community care (non-VA) services. Mono users were defined as those who only received VA services. There were 77,225 dual-system users, and 442,824 mono users. Outcomes were three binary measures: new opioid prescription, continued opioid prescription (i.e., received an additional opioid prescription), and OUD diagnosis (during the calendar year). We conducted a multivariate logistic regression accounting for the repeated observations on patient and intra-class correlations within patients.

Results

Dual-system users were significantly younger than mono users, more likely to be women, and less likely to report white race. In adjusted models, dual-system users were significantly more likely to receive a new opioid prescription during the observation period [Odds ratio (OR) = 1.85, 95% confidence interval (CI) 1.76-1.93], continue prescriptions (OR = 1.24, CI 1.22-1.27), and to receive an OUD diagnosis (OR = 1.20, CI 1.14-1.27).

Discussion

The prevalence of opioid prescriptions has been declining in the US healthcare systems including VA, yet the prevalence of OUD has not been declining at the same rate. One potential problem is that detailed notes from non-VA visits are not immediately available to VA clinicians, and information about VA care is not readily available to non-VA sources. One implication of our findings is that better health system coordination is needed. Even though care was paid for by the VA and presumably closely monitored, dual-system users were more likely to have new and continued opioid prescriptions.

Medication Use Evaluation of High-Dose Long-Term Opioid De-prescribing in Multiple Veterans Affairs Medical Centers

BACKGROUND

The Opioid Safety Initiative (OSI) was implemented in 2013 to enhance the safe and appropriate use of opioids in the Veterans Health Administration (VA). Opioid use decreased nationally in subsequent years, but characterization of opioid de-prescribing practices has not been well established.

OBJECTIVES

To describe changes in patient characteristics and patterns of de-prescribing since OSI implementation for opioid users at > 90 morphine equivalent daily dose for at least 90 days for those that discontinued opioids within the VA.

DESIGN

Retrospective observational pre-post intervention medication use evaluation using VA data and electronic health records to identify differences in opioid de-prescribing between fiscal year 2013 (FY13; early OSI) and FY17 (late OSI). Reviewers' insights for local opioid management and de-prescribing practices collected through web-based post-data collection survey.

PARTICIPANTS

Veterans prescribed high-dose long-term opioid therapy in FY13 and FY17 who subsequently discontinued opioids at 27 VA medical centers.

MAIN MEASURES

Chart review data from local facility reviewers identified socioeconomic characteristics, opioid de-prescribing rationale (e.g., risk-benefit, diversion) and practices (e.g., rate of opioid discontinuation, taper monitoring activities, withdrawal monitoring), and outcomes following discontinuation.

KEY RESULTS

Among 315 patients in FY13 and 322 patients in FY17 with opioid discontinuation, discontinuation rationale focused on diversion in FY13 and risk-benefit in FY17. Clinical pharmacists and pain management specialists had increased involvement in FY17 opioid discontinuations (36% versus 16%). Of all discontinuations, 56% of patients were tapered in FY13 versus 70% of patients in FY17. Tapering plans were longer in FY17 than in FY13 (163 days versus 65 days). Transitions to non-opioid pain therapy following opioid discontinuation were higher in FY17 compared to FY13 (70% versus 60%).

CONCLUSIONS

Veterans discontinued from high-dose long-term opioids in FY17 were more optimally managed compared to those in FY13. Findings suggest improvements in opioid de-prescribing following OSI implementation, but interpretation is limited by study design.

Association of a Positive Drug Screening for Cannabis With Mortality and Hospital Visits Among Veterans Affairs Enrollees Prescribed Opioids

IMPORTANCE

Cannabis has been proposed as a therapeutic with potential opioid-sparing properties in chronic pain, and its use could theoretically be associated with decreased amounts of opioids used and decreased risk of mortality among individuals prescribed opioids.

OBJECTIVE

To examine the risks associated with cannabis use among adults prescribed opioid analgesic medications.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted among individuals aged 18 years and older who had urine drug screening in 2014 to 2019 and received any prescription opioid in the prior 90 days or long-term opioid therapy (LTOT), defined as more than 84 days of the prior 90 days, through the Veterans Affairs health system. Data were analyzed from November 2020 through March 2022.

EXPOSURES

Biologically verified cannabis use from a urine drug screen.

MAIN OUTCOMES AND MEASURES

The main outcomes were 90-day and 180-day all-cause mortality. A composite outcome of all-cause emergency department (ED) visits, all-cause hospitalization, or all-cause mortality was a secondary outcome. Weights based on the propensity score were used to reduce confounding, and hazard ratios [HRs] were estimated using Cox proportional hazards regression models. Analyses were conducted among the overall sample of patients who received any prescription opioid in the prior 90 days and were repeated among those who received LTOT. Analyses were repeated among adults aged 65 years and older.

RESULTS

Among 297 620 adults treated with opioids, 30 514 individuals used cannabis (mean [SE] age, 57.8 [10.5] years; 28 784 [94.3%] men) and 267 106 adults did not (mean [SE] age, 62.3 [12.3] years; P < .001; 247 684 [92.7%] men; P < .001). Among all patients, cannabis use was not associated with increased all-cause mortality at 90 days (HR, 1.07; 95% CI, 0.92-1.22) or 180 days (HR, 1.00; 95% CI, 0.90-1.10) but was associated with an increased hazard of the composite outcome at 90 days (HR, 1.05; 95% CI, 1.01-1.07) and 180 days (HR, 1.04; 95% CI, 1.01-1.06). Among 181 096 adults receiving LTOT, cannabis use was not associated with increased risk of all-cause mortality at 90 or 180 days but was associated with an increased hazard of the composite outcome at 90 days (HR, 1.05; 95% CI, 1.02-1.09) and 180 days (HR, 1.05; 95% CI, 1.02-1.09). Among 77 791 adults aged 65 years and older receiving LTOT, cannabis use was associated with increased 90-day mortality (HR, 1.55; 95% CI, 1.17-2.04).

CONCLUSIONS AND RELEVANCE

This study found that cannabis use among adults receiving opioid analgesic medications was not associated with any change in mortality risk but was associated with a small increased risk of adverse outcomes and that short-term risks were higher among older adults receiving LTOT.

Characteristics and Gender Differences of Headache in the Veterans Health Administration: A National Cohort Study, Fiscal Year 2008-2019

BACKGROUND AND OBJECTIVES

To determine gender differences in headache types diagnosed, sociodemographic characteristics, military campaign and exposures, and health care utilization among US veterans in the Veterans Health Administration (VHA).

METHODS

This study used a retrospective cohort design to examine VHA electronic health record (EHR) data. This cohort includes veterans who had at least 1 visit for any headache between fiscal years 2008 and 2019. Headache diagnoses were classified into 8 categories using International Classification of Disease, Clinical Modification codes. Demographics, military-related exposures, comorbidities, and type of provider(s) consulted were extracted from the EHR and compared by gender. Age-adjusted incidence and prevalence rates of medically diagnosed headache disorders were calculated separately for each type of headache.

RESULTS

Of the 1,524,960 veterans with headache diagnoses included in the cohort, 82.8% were men. Compared with women, men were more often White (70.4% vs 56.7%), older (52.0 ± 16.8 vs 41.9 ± 13.0 years), with higher rates of traumatic brain injury (2.9% vs 1.1%) and post-traumatic stress disorder (23.7% vs 21.7%), and lower rates of military sexual trauma (3.2% vs 33.7%; p < 0.001 for all). Age-adjusted incidence rate of headache of any type was higher among women. Migraine and trigeminal autonomic cephalalgia rates were most stable over time. Men were more likely than women to be diagnosed with headache not otherwise specified (77.4% vs 67.7%) and have higher incidence rates of headaches related to trauma (3.4% vs 1.9% [post-traumatic]; 5.5% vs 5.1% [postwhiplash]; p < 0.001 for all). Men also had fewer headache types diagnosed (mean ± SD; 1.3 ± 0.6 vs 1.5 ± 0.7), had fewer encounters for headache/year (0.8 ± 1.2 vs 1.2 ± 1.6), and fewer visits to headache specialists (20.8% vs 27.4% p < 0.001 for all), compared with women. Emergency department utilization for headache care was high for both genders and higher for women compared with men (20.3% vs 22.9%; p < 0.001).

DISCUSSION

Among veterans with headache diagnoses, important gender differences exist for men and women veterans receiving headache care within VHA regarding sociodemographic characteristics, headache diagnoses, military exposure, and headache health care utilization. The findings have potential implications for providers and the health care system caring for veterans living with headache.

Research approaches for evaluating opioid sparing in clinical trials of acute and chronic pain treatments: Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials recommendations

ABSTRACT

Randomized clinical trials have demonstrated the efficacy of opioid analgesics for the treatment of acute and chronic pain conditions, and for some patients, these medications may be the only effective treatment available. Unfortunately, opioid analgesics are also associated with major risks (eg, opioid use disorder) and adverse outcomes (eg, respiratory depression and falls). The risks and adverse outcomes associated with opioid analgesics have prompted efforts to reduce their use in the treatment of both acute and chronic pain. This article presents Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus recommendations for the design of opioid-sparing clinical trials. The recommendations presented in this article are based on the following definition of an opioid-sparing intervention: any intervention that (1) prevents the initiation of treatment with opioid analgesics, (2) decreases the duration of such treatment, (3) reduces the total dosages of opioids that are prescribed for or used by patients, or (4) reduces opioid-related adverse outcomes (without increasing opioid dosages), all without causing an unacceptable increase in pain. These recommendations are based on the results of a background review, presentations and discussions at an IMMPACT consensus meeting, and iterative drafts of this article modified to accommodate input from the co-authors. We discuss opioid sparing definitions, study objectives, outcome measures, the assessment of opioid-related adverse events, incorporation of adequate pain control in trial design, interpretation of research findings, and future research priorities to inform opioid-sparing trial methods. The considerations and recommendations presented in this article are meant to help guide the design, conduct, analysis, and interpretation of future trials.

Development and field testing of primary care screening tools for harms of long-term opioid therapy continuation and tapering to discontinuation: a study protocol

INTRODUCTION

Despite calls for screening tools to help providers monitor long-term opioid therapy (LTOT) harms, and identify patients likely to experience harms of discontinuation, such screening tools do not yet exist. Current assessment tools are infeasible to use routinely in primary care and focus mainly on behaviours suggestive of opioid use disorder to the exclusion of other potential harms. This paper describes a study protocol to develop two screening tools that comprise one integrated instrument, Screen to Evaluate and Treat (SET). SET1 will indicate if LTOT may be harmful to continue (yes or no), and SET2 will indicate if tapering to discontinue opioids may be harmful to initiate (yes or no). Patients receiving LTOT who screen positive on the SET tools should receive subsequent additional assessment. SET will give providers methods that are feasible to implement routinely to facilitate more intensive and comprehensive monitoring of patients on LTOT and decision-making about discontinuation.

METHODS AND ANALYSIS

We will develop the screening tools, SET1 and SET2, concurrently. Tool development will be done in stages: (1) comprehensive literature searches to yield an initial item pool for domains covered by each screening tool; (2) qualitative item analyses using interviews, expert review and cognitive interviewing, with subsequent item revision, to yield draft versions of each tool; and (3) field testing of the draft screening tools to assess internal consistency, test-retest reliability and convergent and discriminant validity.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Institutional Review Boards of Stanford University and the University of California, San Francisco for the VA Palo Alto Health Care System, and the VA San Francisco Healthcare System, respectively. Findings will be disseminated through peer-reviewed manuscripts and presentations at research conferences.

Opportunities for improving opioid disposal practices in the Veterans Health Administration

Disclaimer

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

Purpose

The potentially vast supply of unused opioids in Americans’ homes has long been a public health concern. We conducted a needs assessment of how Veterans Affairs (VA) facilities address and manage disposal of unused opioid medications to identify opportunities for improvement.

Methods

We used rapid qualitative content analysis methods with team consensus to synthesize findings. Data were collected in 2 waves: (1) semistructured interviews with 19 providers in October 2019 and (2) structured questions to 21 providers in March to April of 2020 addressing how coronavirus disease 2019 (COVID-19) changed disposal priorities.

Results

While many diverse strategies have been tried in the VA, we found limited standardization of advice on opioid disposal and practices nationally. Providers offered the following recommendations: target specific patient scenarios for enhanced disposal efforts, emphasize mail-back envelopes, keep recommendations to providers and patients consistent and reinforce existing guidance, explore virtual modalities to monitor disposal activity, prioritize access to viable disposal strategies, and transition from pull to push communication. These themes were identified in the fall of 2019 and remained salient in the context of the COVID-19 pandemic.

Conclusion

A centralized VA national approach could include proactive communication with patients and providers, interventions tailored to specific settings and populations, and facilitated access to disposal options. All of the above strategies are feasible in the context of an extended period of social distancing.

Telehealth and rural-urban differences in receipt of pain care in the Veterans Health Administration

OBJECTIVE

Examine changes in specialty pain utilization in the Veterans Health Administration (VHA) after establishing a virtual interdisciplinary pain team (TelePain).

DESIGN

Retrospective cohort study.

SETTING

A single VHA healthcare system, 2015-2019.

SUBJECTS

33,169 patients with chronic pain-related diagnoses.

METHODS

We measured specialty pain utilization (in-person and telehealth) among patients with moderate to severe chronic pain. We used generalized estimating equations to test the association of time (pre- or post-TelePain) and rurality on receipt of specialty pain care.

RESULTS

Among patients with moderate to severe chronic pain, the reach of specialty pain care increased from 11.1% to 16.2% in the pre- to post-TelePain periods (aOR: 1.37, 95% CI: 1.26-1.49). This was true of both urban patients (aOR: 1.62, 95% CI: 1.53-1.71) and rural patients (aOR: 1.16, 95% CI: 0.99-1.36), although the difference for rural patients was not statistically significant. Among rural patients who received specialty pain care, a high percentage of the visits were delivered by telehealth (nearly 12% in the post-TelePain period), much higher than among urban patients (3%).

CONCLUSIONS

We observed increased use of specialty pain services among all patients with chronic pain. Although rural patients did not achieve the same degree of access and utilization overall as urban patients, their use of pain telehealth increased substantially and may have substituted for in-person visits. Targeted implementation efforts may be needed to further increase the reach of services to patients living in areas with limited specialty pain care options.

Barriers to and Facilitators of Multimodal Chronic Pain Care for Veterans: A National Qualitative Study

OBJECTIVE

Chronic pain is more common among veterans than among the general population. Expert guidelines recommend multimodal chronic pain care. However, there is substantial variation in the availability and utilization of treatment modalities in the Veterans Health Administration. We explored health care providers' and administrators' perspectives on the barriers to and facilitators of multimodal chronic pain care in the Veterans Health Administration to understand variation in the use of multimodal pain treatment modalities.

METHODS

We conducted semi-structured qualitative interviews with health care providers and administrators at a national sample of Veterans Health Administration facilities that were classified as either early or late adopters of multimodal chronic pain care according to their utilization of nine pain-related treatments. Interviews were conducted by telephone, recorded, and transcribed verbatim. Transcripts were coded and analyzed through the use of team-based inductive and deductive content analysis.

RESULTS

We interviewed 49 participants from 25 facilities from April through September of 2017. We identified three themes. First, the Veterans Health Administration's integrated health care system is both an asset and a challenge for multimodal chronic pain care. Second, participants discussed a temporal shift from managing chronic pain with opioids to multimodal treatment. Third, primary care teams face competing pressures from expert guidelines, facility leadership, and patients. Early- and late-adopting sites differed in perceived resource availability.

CONCLUSIONS

Health care providers often perceive inadequate support and resources to provide multimodal chronic pain management. Efforts to improve chronic pain management should address both organizational and patient-level challenges, including primary care provider panel sizes, accessibility of training for primary care teams, leadership support for multimodal pain care, and availability of multidisciplinary pain management resources.

Implementation and Policy Recommendations from the VHA State-of-the-Art Conference on Strategies to Improve Opioid Safety

Evidence-based treatment of opioid use disorder, the prevention of opioid overdose and other opioid-related harms, and safe and effective pain management are priorities for the Veterans Health Administration (VHA). The VHA Office of Health Services Research and Development hosted a State-of-the-Art Conference on "Effective Management of Pain and Addiction: Strategies to Improve Opioid Safety" on September 10-11, 2019. This conference convened a multidisciplinary group to discuss and achieve consensus on a research agenda and on implementation and policy recommendations to improve opioid safety for Veterans. Participants were organized into three workgroups: (1) managing opioid use disorder; (2) Long-term opioid therapy and opioid tapering; (3) managing co-occurring pain and substance use disorder. Here we summarize the implementation and policy recommendations of each workgroup and highlight important cross-cutting issues related to telehealth, care coordination, and stepped care model implementation.

Core Outcome Measures for Chronic Musculoskeletal Pain Research: Recommendations from a Veterans Health Administration Work Group

OBJECTIVE

Chronic musculoskeletal pain (CMSP) disorders are among the most prevalent and disabling conditions worldwide. It would be advantageous to have common outcome measures when comparing results across different CMSP research studies.

METHODS

The Veterans Health Administration appointed a work group to recommend core outcome measures for assessing pain intensity and interference as well as important secondary domains in clinical research. The work group used three streams of data to inform their recommendations: 1) literature synthesis augmented by three recently completed trials; 2) review and comparison of measures recommended by other expert groups; 3) two Delphi surveys of work group members.

RESULTS

The single-item numerical rating scale and seven-item Brief Pain Inventory interference scale emerged as the recommended measures for assessing pain intensity and interference, respectively. The secondary domains ranked most important included physical functioning and depression, followed by sleep, anxiety, and patient-reported global impression of change (PGIC). For these domains, the work group recommended the Patient-Reported Outcome Information System four-item physical function and sleep scales, the Patient Health Questionnaire two-item depression scale, the Generalized Anxiety Disorder two-item anxiety scale, and the single-item PGIC. Finally, a single-item National Health Interview Survey item was favored for defining chronic pain.

CONCLUSIONS

Two scales comprising eight items are recommended as core outcome measures for pain intensity and interference in all studies of chronic musculoskeletal pain, and brief scales comprising 13 additional items can be added when possible to assess important secondary domains.

Pain Management Best Practices from Multispecialty Organizations During the COVID-19 Pandemic and Public Health Crises

BACKGROUND

It is nearly impossible to overestimate the burden of chronic pain, which is associated with enormous personal and socioeconomic costs. Chronic pain is the leading cause of disability in the world, is associated with multiple psychiatric comorbidities, and has been causally linked to the opioid crisis. Access to pain treatment has been called a fundamental human right by numerous organizations. The current COVID-19 pandemic has strained medical resources, creating a dilemma for physicians charged with the responsibility to limit spread of the contagion and to treat the patients they are entrusted to care for.

METHODS

To address these issues, an expert panel was convened that included pain management experts from the military, Veterans Health Administration, and academia. Endorsement from stakeholder societies was sought upon completion of the document within a one-week period.

RESULTS

In these guidelines, we provide a framework for pain practitioners and institutions to balance the often-conflicting goals of risk mitigation for health care providers, risk mitigation for patients, conservation of resources, and access to pain management services. Specific issues discussed include general and intervention-specific risk mitigation, patient flow issues and staffing plans, telemedicine options, triaging recommendations, strategies to reduce psychological sequelae in health care providers, and resource utilization.

CONCLUSIONS

The COVID-19 public health crisis has strained health care systems, creating a conundrum for patients, pain medicine practitioners, hospital leaders, and regulatory officials. Although this document provides a framework for pain management services, systems-wide and individual decisions must take into account clinical considerations, regional health conditions, government and hospital directives, resource availability, and the welfare of health care providers.

Treatment of a Large Cohort of Veterans Experiencing Musculoskeletal Disorders with Spinal Cord Stimulation in the Veterans Health Administration: Veteran Characteristics and Outcomes

OBJECTIVE

Spinal cord stimulator (SCS) implantation is used to treat chronic pain, including painful musculoskeletal disorders (MSDs). This study examined the characteristics and outcomes of veterans receiving SCSs in Veterans Health Administration (VHA) facilities.

METHODS

The sample was drawn from the MSD Cohort and limited to three MSDs with the highest number of implants (N=815,475). There were 1490 veterans with these conditions who received SCS implants from 2000 to 2012, of which 95% (n=1414) had pain intensity numeric rating scale (NRS) data both pre- and post-implant.

RESULTS

Veterans who were 35-44 years old, White, and married reported higher pain NRS ratings, had comorbid inclusion diagnoses, had no medical comorbidities, had a BMI 25-29.9, or had a depressive disorder diagnosis were more likely to receive an SCS. Veterans 55+ years old or with an alcohol or substance use disorder were less likely to receive an SCS. Over 90% of those receiving an SCS were prescribed opioids in the year prior to implant. Veterans who had a presurgical pain score ≥4 had a clinically meaningful decrease in their pain score in the year following their 90-day recovery period (Day 91-456) greater than expected by chance alone. Similarly, there was a significant decrease in the percent of veterans receiving opioid therapy (92.4% vs 86.6%, p<0.0001) and a significant overall decrease in opioid dose [morphine equivalent dose per day (MEDD) =26.48 vs MEDD=22.59, p<0.0003].

CONCLUSION

Results offer evidence of benefit for some veterans with the examined conditions. Given known risks of opioid therapy, the reduction is an important potential benefit of SCS implants.

Associations between stopping prescriptions for opioids, length of opioid treatment, and overdose or suicide deaths in US veterans: observational evaluation

OBJECTIVE

To examine the associations between stopping treatment with opioids, length of treatment, and death from overdose or suicide in the Veterans Health Administration.

DESIGN

Observational evaluation.

SETTING

Veterans Health Administration.

PARTICIPANTS

1 394 102 patients in the Veterans Health Administration with an outpatient prescription for an opioid analgesic from fiscal year 2013 to the end of fiscal year 2014 (1 October 2012 to 30 September 2014).

MAIN OUTCOME MEASURES

A multivariable Cox non-proportional hazards regression model examined death from overdose or suicide, with the interaction of time varying opioid cessation by length of treatment (≤30, 31-90, 91-400, and >400 days) as the main covariates. Stopping treatment with opioids was measured as the time when a patient was estimated to have no prescription for opioids, up to the end of the next fiscal year (2014) or the patient's death.

RESULTS

2887 deaths from overdose or suicide were found. The incidence of stopping opioid treatment was 57.4% (n=799 668) overall, and based on length of opioid treatment was 32.0% (≤30 days), 8.7% (31-90 days), 22.7% (91-400 days), and 36.6% (>400 days). The interaction between stopping treatment with opioids and length of treatment was significant (P<0.001); stopping treatment was associated with an increased risk of death from overdose or suicide regardless of the length of treatment, with the risk increasing the longer patients were treated. Hazard ratios for patients who stopped opioid treatment (with reference values for all other covariates) were 1.67 (≤30 days), 2.80 (31-90 days), 3.95 (91-400 days), and 6.77 (>400 days). Descriptive life table data suggested that death rates for overdose or suicide increased immediately after starting or stopping treatment with opioids, with the incidence decreasing over about three to 12 months.

CONCLUSIONS

Patients were at greater risk of death from overdose or suicide after stopping opioid treatment, with an increase in the risk the longer patients had been treated before stopping. Descriptive data suggested that starting treatment with opioids was also a risk period. Strategies to mitigate the risk in these periods are not currently a focus of guidelines for long term use of opioids. The associations observed cannot be assumed to be causal; the context in which opioid prescriptions were started and stopped might contribute to risk and was not investigated. Safer prescribing of opioids should take a broader view on patient safety and mitigate the risk from the patient's perspective. Factors to address are those that place patients at risk for overdose or suicide after beginning and stopping opioid treatment, especially in the first three months.

VA/DoD Clinical Practice Guideline: Diagnosis and Treatment of Low Back Pain

DESCRIPTION

In September 2017, the U.S. Department of Veterans Affairs (VA) and U.S. Department of Defense (DoD) approved the joint Clinical Practice Guideline (CPG) for Diagnosis and Management of Low Back Pain. This CPG was intended to provide healthcare providers a framework by which to evaluate, treat, and manage patients with low back pain (LBP).

METHODS

The VA/DoD Evidence-Based Practice Work Group convened a joint VA/DoD guideline development effort that included a multidisciplinary panel of practicing clinician stakeholders and conformed to the Institute of Medicine's tenets for trustworthy clinical practice guidelines. The guideline panel developed key questions in collaboration with the ECRI Institute, which systematically searched and evaluated the literature through September 2016, developed an algorithm, and rated recommendations by using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. A patient focus group was also convened to ensure patient values and perspectives were considered when formulating preferences and shared decision making in the guideline.

RECOMMENDATIONS

The VA/DOD LBP CPG provides evidence-based recommendations for the diagnostic approach, education and self-care, non-pharmacologic and non-invasive therapy, pharmacologic therapy, dietary supplements, non-surgical invasive therapy, and team approach to treatment of low back pain.

Medications for opioid use disorder in the Department of Veterans Affairs (VA) health care system: Historical perspective, lessons learned, and next steps

The US Department of Veterans Affairs (VA), the largest health care system in the US, has been confronted with the health care consequences of opioid disorder (OUD). Increasing access to quality OUD treatment, including pharmacotherapy, is a priority for the VA. We examine the history of medications (e.g., methadone, buprenorphine, injectable naltrexone) used in the treatment of OUD within VA, document early and ongoing efforts to increase access and build capacity, primarily through the use of buprenorphine, and summarize research examining barriers and facilitators to prescribing and medication receipt. We find that there has been a slow but steady increase in the use of medications for OUD and, despite system-wide mandates and directives, uneven uptake across VA facilities and within patient sub-populations, including some of those most vulnerable. We conclude with recommendations intended to support the greater use of medication for OUD in the future, both within VA as well as other large health care systems.

The Socioeconomic Burden of Pain From War

War's burden on the health and well-being of combatants, civilians, and societies is well documented. Although the examination of soldiers' injuries in modern combat is both detailed and comprehensive, less is known about war-related injuries to civilians and refugees, including victims of torture. The societal burden of war-related disabilities persists for decades in war's aftermath. The complex injuries of combat survivors, including multiple pain conditions and neuropsychiatric comorbidities, challenge health care systems to reorganize care to meet these survivors' special needs.We use the case study method to illustrate the change in pain management strategies for injured combat survivors in one national health system, the US Department of Veterans Affairs (VA). The care of veterans' disabling injuries suffered in Vietnam contrasts with the care resulting from the VA's congressional mandate to design and implement a pain management policy that provides effective pain management to veterans injured in the recent Middle East conflicts.The outcomes-driven, patient-centric Stepped Care Model of biopsychosocial pain management requires system-wide patient education, clinician training, social networking, and administrative monitoring. Societies are encouraged to develop their health care system's capacity to effectively respond to the victims of warfare, including combatants and refugees.

Clinical Policy Recommendations from the VHA State-of-the-Art Conference on Non-Pharmacological Approaches to Chronic Musculoskeletal Pain

As a large national healthcare system, Veterans Health Administration (VHA) is ideally suited to build on its work to date and develop a safe, evidence-based, and comprehensive approach to the care of chronic musculoskeletal pain conditions that de-emphasizes opioid use and emphasizes non-pharmacological strategies. The VHA Office of Health Services Research and Development (HSR&D) held a state-of-the-art (SOTA) conference titled "Non-pharmacological Approaches to Chronic Musculoskeletal Pain Management" in November 2016. Goals of the conference were (1) to establish consensus on the current state of evidence regarding non-pharmacological approaches to chronic musculoskeletal pain to inform VHA policy in this area and (2) to begin to identify priorities for the future VHA research agenda. Workgroups were established and asked to reach consensus recommendations on clinical and research priorities for the following treatment strategies: psychological/behavioral therapies, exercise/movement therapies, manual therapies, and models for delivering multimodal pain care. Participants in the SOTA identified nine non-pharmacological therapies with sufficient evidence to be implemented across the VHA system as part of pain care. Participants further recommended that effective integration of these non-pharmacological approaches across the VHA and especially into VHA primary care, pain care, and mental health settings should be a priority, and that these treatments should be offered early in the course of pain treatment and delivered in a team-based, multimodal treatment setting concurrently with active self-care and self-management approaches. In addition, we recommend that VHA leadership and policy makers systematically address the barriers to implementation of these approaches by expanding opportunities for clinician and veteran education on the effectiveness of these strategies; supporting and funding further research to determine optimal dosage, duration, sequencing, combination, and frequency of treatment; emphasizing multimodal care with rigorous evaluation grounded in team-based approaches to test integrated models of delivery and stepped-care approaches; and working to address socioeconomic and cultural barriers to veterans' access to non-pharmacological approaches.

Self-reported post-exertional fatigue in Gulf War veterans: roles of autonomic testing

To determine if objective evidence of autonomic dysfunction exists from a group of Gulf War veterans with self-reported post-exertional fatigue, we evaluated 16 Gulf War ill veterans and 12 Gulf War controls. Participants of the ill group had self- reported, unexplained chronic post-exertional fatigue and the illness symptoms had persisted for years until the current clinical study. The controls had no self-reported post-exertional fatigue either at the time of initial survey nor at the time of the current study. We intended to identify clinical autonomic disorders using autonomic and neurophysiologic testing in the clinical context. We compared the autonomic measures between the 2 groups on cardiovascular function at both baseline and head-up tilt, and sudomotor function. We identified 1 participant with orthostatic hypotension, 1 posture orthostatic tachycardia syndrome, 2 distal small fiber neuropathy, and 1 length dependent distal neuropathy affecting both large and small fiber in the ill group; whereas none of above definable diagnoses was noted in the controls. The ill group had a significantly higher baseline heart rate compared to controls. Compound autonomic scoring scale showed a significant higher score (95% CI of mean: 1.72–2.67) among ill group compared to controls (0.58–1.59). We conclude that objective autonomic testing is necessary for the evaluation of self-reported, unexplained post-exertional fatigue among some Gulf War veterans with multi-symptom illnesses. Our observation that ill veterans with self-reported post-exertional fatigue had objective autonomic measures that were worse than controls warrants validation in a larger clinical series.

Paired associative stimulation

Paired associative stimulation (PAS) refers to a paradigm consisting of slow-rate repetitive low-frequency median nerve stimulation combined with transcranial magnetic stimulation (TMS) over the contralateral motor cortex. This protocol has been shown to induce plastic changes of excitability in the human motor cortex. Its principles of design were shaped after associative long-term potentiation (LTP) in experimental animals, a cellular mechanism likely to be relevant for learning and memory. PAS-induced changes of cortical excitability share a number of physiological properties with LTP. Of particular importance is the fact that the sign of PAS-induced changes of the size of amplitudes of the motor evoked potentials (MEPs) depends on the exact interval between the afferent and the magnetic pulse during the intervention. A number of observations suggest that PAS-induced excitability changes may have functional significance. PAS-induced plasticity may contribute to elucidating the pathogenesis of neurological disorders where neuroplasticity is thought to have a pathogenetic role. Finally, PAS-induced plasticity may itself have therapeutic potential.

A temporally asymmetric Hebbian rule governing plasticity in the human motor cortex

Synaptic plasticity is conspicuously dependent on the temporal order of the pre- and postsynaptic activity. Human motor cortical excitability can be increased by a paired associative stimulation (PAS) protocol. Here we show that it can also be decreased by minimally changing the interval between the two associative stimuli. Corticomotor excitability of the abductor pollicis brevis (APB) representation was tested before and after repetitively pairing of single right median nerve simulation with single pulse transcranial magnetic stimulation (TMS) delivered over the optimal site for activation of the contralateral APB. Following PAS, depression of TMS-evoked motor-evoked potentials (MEPs) was induced only when the median nerve stimulation preceded the TMS pulse by 10 ms, while enhancement of cortical excitability was induced using an interstimulus interval of 25 ms, suggesting an important role of the sequence of cortical events triggered by the two stimulation modalities. Experiments using F-wave studies and electrical brain stem stimulation indicated that the site of the plastic changes underlying the decrease of MEP amplitudes following PAS (10 ms) was within the motor cortex. MEP amplitudes remained depressed for approximately 90 min. The decrease of MEP amplitudes was blocked when PAS(10 ms) was performed under the influence of dextromethorphan, an N-methyl-d-aspartate-receptor antagonist, or nimodipine, an L-type voltage-gated calcium-channel antagonist. The physiological profile of the depression of human motor cortical excitability following PAS(10 ms) suggests long-term depression of synaptic efficacy to be involved. Together with earlier findings, this study suggests that strict temporal Hebbian rules govern the induction of long-term potentiation/long-term depression-like phenomena in vivo in the human primary motor cortex.

Thalidomide neuropathy in patients treated for metastatic prostate cancer

We prospectively evaluated thalidomide-induced neuropathy using electrodiagnostic studies. Sixty-seven men with metastatic androgen-independent prostate cancer in an open-label trial of oral thalidomide underwent neurologic examinations and nerve conduction studies (NCS) prior to and at 3-month intervals during treatment. NCS included recording of sensory nerve action potentials (SNAPs) from median, radial, ulnar, and sural nerves. SNAP amplitudes for each nerve were expressed as the percentage of its baseline, and the mean of the four was termed the SNAP index. A 40% decline in the SNAP index was considered clinically significant. Thalidomide was discontinued in 55 patients for lack of therapeutic response. Of 67 patients initially enrolled, 24 remained on thalidomide for 3 months, 8 remained at 6 months, and 3 remained at 9 months. Six patients developed neuropathy. Clinical symptoms and a decline in the SNAP index occurred concurrently. Older age and cumulative dose were possible contributing factors. Neuropathy may thus be a common complication of thalidomide in older patients. The SNAP index can be used to monitor peripheral neuropathy, but not for early detection.

"Pseudo-conduction block" in a patient with vasculitic neuropathy

A 63-year-old man presented with progressive asymmetric weakness and numbness in his hands of 2 weeks duration. Nerve conduction studies showed low amplitude motor evoked potentials of both median nerves. The right ulnar, left tibial and peroneal nerves had normal potentials on distal stimulation with markedly decreased amplitudes proximally, suggestive of "conduction block". Three weeks later, amplitudes were decreased throughout. The patient was diagnosed with vasculitis. The acute ischemic injury presumably resulted in axonal damage between the distal and proximal stimulation sites, with subsequent Wallerian degeneration.

Motor cortex excitability in stiff-person syndrome

Muscle stiffness in stiff-person syndrome (SPS) is produced by continuous, involuntary firing of motor units that is thought to be caused by an autoimmune mediated dysfunction of GABA-ergic inhibitory neurones. We have postulated that the loss of GABA-ergic inputs from spinal interneurones alone is insufficient to produce tonic firing of motor neurones and that excessive supraspinal excitation could also play a role. To determine whether SPS is associated with dysfunction in supraspinal GABA-ergic neurones, we assessed the excitability of the motor cortex with transcranial magnetic stimulation (TMS) in seven SPS patients and seven age-matched healthy volunteers. SPS patients had normal central motor conduction times, normal thresholds for motor evoked potentials (MEPs) in leg muscles, and a normal MEP stimulus versus response recruitment curve with increasing TMS intensities in resting hand and leg muscles. Cortical silent periods were shortened in leg muscles. Intracortical inhibition and excitation were assessed while recording from the abductor pollicis brevis, using a paired pulse TMS paradigm with subthreshold conditioning stimuli. Patients had decreased inhibition and markedly increased facilitation at short intervals. Using paired suprathreshold TMS, patients exhibited increased facilitation at 20- and 40-ms intervals. These results point to a hyperexcitability of the motor cortex in SPS, which could be explained by impairment of supraspinal GABA-ergic neurones, leading to an impaired balance between inhibitory and excitatory intracortical circuitry.

Cutaneous silent periods in patients with Fabry disease

We assessed the cutaneous silent period (CSP) in 24 patients with Fabry disease with small-fiber sensory neuropathy and 12 normal subjects to test the hypothesis that small-diameter afferents are responsible for producing the CSP. Sensory nerve conduction studies and quantitative sensory testing for cold and vibration detection thresholds were also measured. Overall, Fabry patients had impaired thermal, but not vibration, detection thresholds, with greatest impairment in the feet. In the upper extremity, CSP latencies, duration, and suppression of electromyographic activity (EMG) did not differ. In the lower extremity, patients had reduced suppression of EMG during the CSP compared to normal controls. CSP durations exhibited a bimodal distribution in patients, including a subset of seven patients with durations shorter than all controls. This subset had profound loss of thermal sensation in the feet, but this was also true of some patients who had normal CSPs. Patients with shortened CSPs had modestly elevated vibration thresholds and reduced sensory potentials in comparison to patients with normal CSPs. Reduced CSPs in Fabry patients are associated with, but not entirely explained by, the severity of small-fiber neuropathy as measured by quantitative sensory testing. The possibility that large-diameter fibers provide a minor contribution to producing the CSP should be considered.

Blink reflex recovery in facial weakness: an electrophysiologic study of adaptive changes

OBJECTIVE

To study the electrophysiologic effects of unilateral facial weakness on the excitability of the neuronal circuitry underlying blink reflex, and to localize the site of changes in blink reflex excitability that occur after facial weakness.

BACKGROUND

Eyelid kinematic studies suggest that adaptive modification of the blink reflex occurs after facial weakness. Such adaptations generally optimize eye closure. A report of blepharospasm following Bell's palsy suggests that dysfunctional adaptive changes can also occur.

METHODS

Blink reflex recovery was evaluated with paired stimulation of the supraorbital nerve at different interstimulus intervals. Comparisons were made between normal control subjects and patients with Bell's palsy who either recovered facial strength or who had persistent weakness.

RESULTS

Blink reflex recovery was enhanced in patients with residual weakness but not in patients who recovered facial strength. Facial muscles on weak and unaffected sides showed enhancement. In patients with residual weakness, earlier blink reflex recovery occurred when stimulating the supraorbital nerve on the weak side. Sensory thresholds were symmetric.

CONCLUSION

Enhancement of blink reflex recovery is dependent on ongoing facial weakness. Faster recovery when stimulating the supraorbital nerve on the paretic side suggests that sensitization may be lateralized, and suggests a role for abnormal afferent input in maintaining sensitization. Interneurons in the blink reflex pathway are the best candidates for the locus of this plasticity.

Zoster myelitis: improvement with antiviral therapy in two cases

This report describes two patients with acquired immunodeficiency syndrome (AIDS) and herpes zoster myelopathy. Patient one had a T-8 myelitis that preceded the onset of T-8-distribution zoster and was followed by cervical myelopathy. Antibody to varicella zoster virus (VZV) was present in the CSF. He never received steroids or other immunosuppressive drugs, and his condition improved dramatically after treatment with intravenous acyclovir. The second patient had a rapidly progressive myelitis with paralysis of both legs. Detection of VZV DNA and antibody to VZV in his CSF led to successful treatment with famciclovir despite discontinuation of dexamethasone and earlier treatment failure with acyclovir. These cases support the idea that VZV myelopathy in the immunosuppressed host is caused by virus invasion. CSF analysis for antiviral antibody and for VZV DNA by polymerase chain reaction are helpful in establishing the diagnosis. Aggressive antiviral therapy is advised.

Short communication: deletion 7q, trisomy 6 and 11 in a case of Merkel-cell carcinoma

Chromosome analysis of a metastatic Merkel-cell carcinoma established as xenografted tumor line in nude mice was performed. The analyzed karyotypes showed a stable cytogenetic feature characterized by trisomy 6 and 11 and a partial deletion of the long arm of chromosome #7 with the breakpoint localized at q31.2.