Barriers and Facilitators to Optimal Neuropathic Pain Management: SCI Consumer, Significant Other, and Health Care Provider Perspectives.

OBJECTIVE: Persistent neuropathic pain is a common and often severe consequence of spinal cord injury (SCI). There is a critical need to better understand how to overcome barriers and promote facilitators to optimal pain management. The present study was designed to identify, from the perspectives of persons living with SCI, their significant others, and SCI health care professionals, the barriers and facilitators to optimal pain management for intense neuropathic pain. DESIGN: Qualitative interviews. SETTING: University laboratory. SUBJECTS: People with SCI who had experienced intense neuropathic pain for a minimum of a year (N = 15), their significant others (N = 15), and SCI health care providers (N = 15). METHODS: Qualitative interviews were recorded, transcribed, and analyzed based on grounded theory using ATLAS.ti software. RESULTS: Inadequate access to care, information, or pain management expertise were frequently perceived barriers to optimal pain management across all three groups. Another major barrier was SCI stakeholders' concerns regarding the risks of adverse effects and addiction to pain medication. Facilitators included having a better understanding of pain and available treatment options, effective patient-provider communication, resilience, and access to nonpharmacological treatment options. CONCLUSIONS: Managing intense neuropathic pain poses significant challenges after SCI. SCI stakeholders felt that accessible treatment options were limited and primarily focused on pain medications with minimal benefit but with significant risks for addiction and adverse effects. Actionable facilitators to optimal pain management after SCI include education regarding neuropathic pain and treatment options for all stakeholders, better communication regarding neuropathic pain among stakeholders, and improved patient access to nonpharmacological treatment options.

Living With Chronic Pain After Spinal Cord Injury: A Mixed-Methods Study.

OBJECTIVE: To identify the relative importance of positive (facilitators) and negative (barriers) contributors to living with chronic pain after spinal cord injury (SCI). DESIGN: Mixed-methods: (1) Qualitative (n=35): individual, semistructured, open-ended interviews identifying facilitator/barrier themes; (2) Quantitative (n=491): converting the most common themes into statements and quantifying agreement with these in an online survey to determine relative importance, underlying dimensions, and their associations with perceived difficulty in dealing with pain. SETTING: University-based research setting and general community. PARTICIPANTS: Volunteers (N=526) with SCI experiencing moderate to severe chronic pain. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Interview guides, facilitator/barrier statements, and pain inventories. RESULTS: Exploratory factor analyses reduced agreement ratings into 4 facilitators (information regarding pain and treatments, resilience, coping, medication use) and 5 barriers (poor health care communication, pain impact and limitations, poor communication about pain, difficult nature of pain, treatment concerns). Greater "pain impact and limitations," "difficult nature of pain," "poor communication from provider," lower "resilience," greater "medication use," and younger age predicted greater difficulty in dealing with pain (r=.75; F=69.02; P<.001). CONCLUSIONS: This study revealed multiple facilitators and barriers to living with chronic pain after SCI. The principal barrier, "poor health care communication," indicated that consumers do not receive adequate information from their health care providers regarding pain. "Information regarding pain and treatments" had greater agreement scores and factor loadings than all other facilitators, indicating that most participants view provider-patient communication and educational efforts regarding pain and pain management as priorities and critical needs. Further initiatives in these areas are important for improving pain management post-SCI.

Development of a pain education resource for people with spinal cord injury.

Many people with spinal cord injury (SCI) develop chronic pain, including neuropathic pain. Unfortunately, current treatments for this condition are often inadequate because SCI-associated neuropathic pain is complex and depends on various underlying mechanisms and contributing factors. Multimodal treatment strategies including but not limited to pharmacological treatments, physical rehabilitation, cognitive training, and pain education may be best suited to manage pain in this population. In this study, we developed an educational resource named the SeePain based on published pain literature, and direct stakeholder input, including people living with SCI and chronic pain, their significant others, and healthcare providers with expertise in SCI. The SeePain was then 1) systematically evaluated by stakeholders regarding its content, comprehensibility, and format using qualitative interviews and thematic analysis, and 2) modified based on their perspectives. The final resource is a comprehensive guide for people with SCI and their significant others or family members that is intended to increase health literacy and facilitate communication between SCI consumers and their healthcare providers. Future work will quantitatively validate the SeePain in a large SCI sample.

Pain symptom profiles in persons with spinal cord injury.

OBJECTIVE: Persistent pain is a common consequence of spinal cord injury. A patient-specific assessment that combines both the identification of pain symptoms and psychosocial factors is needed for a tailored treatment approach. The aim of the study was to define pain symptom profiles and to determine their relationship with psychosocial factors in persons with spinal cord injury. DESIGN: Face-to-face interview and examination. SETTING: VA Medical Center and Miami Project to Cure Paralysis, Miami, Florida. PATIENTS: Persons with spinal cord injury (135 men and 21 women) provided detailed descriptions of 330 neuropathic pains. OUTCOME MEASURES: The American Spinal Injury Impairment Scale, pain history and measures of pain interference, life satisfaction, locus of control, social support and depression. RESULTS: The exploratory factor analyses and regression analyses revealed three distinct symptom profiles: 1) aching, throbbing pain, aggravated by cold weather and constipation predicted by a combination of chance locus of control and lower levels of life satisfaction; 2) stabbing, penetrating, and constant pain of high intensity predicted by a combination of pain interference, localized pain, powerful others locus of control and depressed mood; and 3) burning, electric, and stinging pain aggravated by touch and muscle spasms predicted by pain interference. CONCLUSIONS: Although these results need to be replicated in other spinal cord injury samples, our findings suggest that pain symptom profiles may be a useful way to further characterize pain in a comprehensive assessment strategy.

Subgroup Perspectives on Chronic Pain and Its Management After Spinal Cord Injury.

The present study was part of a larger mixed-methods study concerning facilitators and barriers to living with chronic pain after spinal cord injury. The agreement with themes obtained in qualitative interviews were quantified in a large online survey and overarching themes were defined by factor analysis. The present study aimed to define subgroups based on cluster analysis of the overarching themes' factor scores and to compare the subgroups on pain-related variables. Three subgroups-high pain impact, moderate pain impact, and low pain impact-emerged. The high pain impact subgroup experienced severe pain with neuropathic pain characteristics; used pain medication, multiple coping strategies, and self-remedies; and considered information about pain and its management critical, but were not able to communicate well about their pain. The moderate pain impact subgroup carried on despite pain, considered pain information important, and used multiple approaches to manage their pain, but used less medication owing to concerns about side effects and addiction. The low pain impact subgroup considered information about pain, pain treatments, and communication regarding pain less important than the other subgroups did. This study suggests that treatment approaches need to be individually tailored not only to type of pain, but also to personal factors and preferences. PERSPECTIVE: People who experience significant pain impact after spinal cord injury use multiple approaches to manage their pain. Many have concerns about side effects and addiction, and consider information about pain and its management, including pharmacologic, nonpharmacologic, and self-remedies, a high priority. Therefore, patients' personal preferences may provide additional tailoring options for patient-centered treatments.

Hypothermia in patients with chronic spinal cord injury.

DESIGN: Retrospective analysis of medical records. BACKGROUND/OBJECTIVES: To determine frequency and degree of hypothermic episodes in patients with chronic spinal cord injury (SCI). SETTING: Veterans Administration Medical Center. METHODS: Research involved analysis of body temperature records of 50 chronic patients with tetraplegia. All patients were men with a length of injury of 19 +/- 6 years. Mean age was 53 +/- 15 (SD) years. Data were derived from the computerized patient record database system of the Veterans Administration Medical Center. Results were classified into 3 groups: (a) hypothermia (< 95 degrees F), (b) subnormal temperature (< 97.7 degrees F), and normal temperatures (97.7 degrees F to 98.4 degrees F). Body temperature was recorded during hospitalization (minimum duration of 30 days) using an oral probe twice a day. Ambient temperature was controlled by a central air-conditioning system and maintained at 72 degrees F to 74 degrees F. RESULTS: A total of 867 measurements of body temperature were evaluated; normal temperature was recorded 298 times (35%), subnormal temperature was recorded 544 times (63%), and hypothermia was recorded 25 times (3%). There were 15 patients with 30 hypothermic episodes; subnormal temperature was found in all 50 patients from 1 to 47 times. Regression analysis of age and duration of SCI showed a nonsignificant relationship with body temperature. CONCLUSIONS: Our data suggest that patients with tetraplegia after SCI have significant dysfunction of thermoregulation associated with frequent episodes of subnormal body temperature in a normal ambient environment. Further studies are needed to evaluate possible consequences of low temperatures on the general health of patients and to develop preventive interventions.

Deep Brain Stimulation Improves the Symptoms and Sensory Signs of Persistent Central Neuropathic Pain from Spinal Cord Injury: A Case Report.

Central neuropathic pain (CNP) is a significant problem after spinal cord injury (SCI). Pharmacological and non-pharmacological approaches may reduce the severity, but relief is rarely substantial. While deep brain stimulation (DBS) has been used to treat various chronic pain types, the technique has rarely been used to attenuate CNP after SCI. Here we present the case of a 54-year-old female with incomplete paraplegia who had severe CNP in the lower limbs and buttock areas since her injury 30 years prior. She was treated with bilateral DBS of the midbrain periaqueductal gray (PAG). The effects of this stimulation on CNP characteristics, severity and pain-related sensory function were evaluated using the International SCI Pain Basic Data Set (ISCIPBDS), Neuropathic Pain Symptom Inventory (NPSI), Multidimensional Pain Inventory and Quantitative Sensory Testing before and periodically after initiation of DBS. After starting DBS treatment, weekly CNP severity ratings rapidly decreased from severe to minimal, paralleled by a substantial reduction in size of the painful area, reduced pain impact and reversal of pain-related neurological abnormalities, i.e., dynamic-mechanical and cold allodynia. She discontinued pain medication on study week 24. The improvement has been consistent. The present study expands on previous findings by providing in-depth assessments of symptoms and signs associated with CNP. The results of this study suggest that activation of endogenous pain inhibitory systems linked to the PAG can eliminate CNP in some people with SCI. More research is needed to better-select appropriate candidates for this type of therapy. We discuss the implications of these findings for understanding the brainstem's control of chronic pain and for future progress in using analgesic DBS in the central gray.

The midbrain central gray best suppresses chronic pain with electrical stimulation at very low pulse rates in two human cases.

Deep brain stimulation in the midbrain׳s central gray can relieve neuropathic pain in man, but for unclear reasons sometimes fails intraoperatively or in early weeks. Here we describe continuous bilateral stimulation in the central gray of two subjects with longstanding, severe neuropathic pain from spinal cord injury. Stimulation parameters were recursively adjusted over many weeks to optimize analgesia while minimizing adverse effects. In early weeks, adjustments were made in periodic office visits; subjects later selected ad libitum at home among several blinded choices while rating pain twice daily. Both subjects received significantly better pain relief when stimulus pulse rates were low. The best relief occurred with 2 Hz cycled on for 1s and off for 2s. After inferior parameters were set, pain typically climbed slowly over 1-2 days; superior parameters led to both slow and fast improvements. Over many weeks of stimulation at low pulse rates, both subjects experienced significantly less interference from pain with sleep. One subject, with major pain relief, also showed less interference with social/recreational ability and mood; the other subject, despite minor pain relief, experienced a significantly positive global impression of change. Oscillopsia, the only observed complication of stimulation, disappeared at low mean pulse rates (≤ 3/s). These subjects׳ responses are not likely to be unique even if they are uncommon. Thus daily or more frequent pain assessment, combined with slower periodic adjustment of stimulation parameters that incorporate mean pulse rates about one per second, will likely improve success with this treatment.

Evidence for an exaggerated postprandial lipemia in chronic paraplegia.

BACKGROUND/OBJECTIVE: Excessive delay in triglyceride (TG) metabolism after ingestion of dietary fat represents a significant cardiovascular disease (CVD) risk. The objective of this study was to compare the postprandial lipemic responses of individuals with paraplegia with those of healthy nondisabled individuals. METHODS: The ability of 3 recreationally active individuals with paraplegia having normal fasting TG (mean = 103 mg/dL) to metabolize TG after ingestion of a high-fat test meal was compared with a previously published cohort of 21 recreationally active individuals without paraplegia (TG mean = 86 mg/dL) who underwent identical testing. The subjects with paraplegia had venous blood taken under fasting conditions, and then ingested a milkshake containing premium ice cream blended with heavy whipping cream (approximately 92% of calories from fat). Additional blood samples were obtained at 2, 4, and 6 hours after ingestion. The area under the curve (AUC) for TG clearance for both subject groups was measured with an area planimeter. RESULTS: TG uptake for both groups was almost identical for the first 2 hours after ingestion. At 4 and 6 hours after ingestion, the TG levels were 50 and 35 mg/dL higher, respectively, in subjects with paraplegia than in nondisabled subjects. When corrected for small baseline differences in TG concentrations (16 mg/dL), the AUC was 46.5% greater for the group with paraplegia than in the nondisabled group. A near mirror association across time was observed between postprandial serum high-density lipoprotein cholesterol (HDL-C) and TG levels in subjects with paraplegia. CONCLUSION: This case series finds an exaggerated postprandial lipemia (PPL) in persons with paraplegia with normal fasting TGs. This finding is the first evidence, in a small population, of an unreported potential CVD risk in persons with paraplegia.

Diabetic demyelinating polyneuropathy responsive to intravenous immunoglobulin therapy.

BACKGROUND: There is growing evidence that idiopathic chronic inflammatory demyelinating polyneuropathy (CIDP) and polyneuropathy in patients with diabetes mellitus (DM) that meets the electrophysiological criteria for CIDP (DM-CIDP) have many similarities. OBJECTIVE: To evaluate whether DM-CIDP responds to intravenous immunoglobulin (IVIG) therapy. PATIENTS AND METHODS: Twenty-six patients (mean [SD] age, 64 [8.9] years; age range, 40-80 years) with type 2 DM (n = 25), who met the electrophysiological criteria for CIDP, were given IVIG therapy (400 mg/kg body weight per day for 5 days) in a prospective open-label pilot study. All patients had quantitative evaluation using the Neuropathy Impairment Score at baseline and at the end of 4 weeks from the initiation of IVIG therapy. RESULTS: The mean Neuropathy Impairment Score improved significantly from baseline (mean [SD], 61.5 [26.0] points) to the end of the fourth week (33 [29.6] points; P<.00l). This clinically significant improvement occurred in 21 (80.8%) of the 26 patients. Conduction block occurred in 11 (42.3%) of the 26 patients; improvement in the Neuropathy Impairment Score was more frequent in patients who had a conduction block (11 of 11 patients) than in those who did not (10/15 [66.7%]; P =.03). Adverse reactions to IVIG included reversible renal dysfunction in 3 patients, flulike symptoms in 5, headache in 5, and chest pain and shortness of breath in 1. CONCLUSION: Although IVIG therapy seemed to improve DM-CIDP in this uncontrolled trial, a controlled trial is required for confirmation of our findings.

Proton magnetic resonance spectroscopy of the thalamus in patients with chronic neuropathic pain after spinal cord injury.

BACKGROUND AND PURPOSE: Spinal cord injury (SCI) results in a number of consequences; one of the most difficult to manage is chronic neuropathic pain. Thus, defining the potential neural and biochemical changes associated with chronic pain after SCI is important because this may lead to development of new treatment strategies. Prior studies have looked at the thalamus, because it is a major sensory relay station. The purpose of our study was to define alterations in metabolites due to injury-induced functional changes in thalamic nuclei by using single-voxel stimulated echo acquisition mode MR spectroscopy. METHODS: Twenty-six men were recruited: 16 patients with SCI and paraplegia (seven with pain, nine without pain) and 10 healthy control subjects. Pain was evaluated in an interview, which included the collection of information concerning the location, quality, and intensity of pain, carefully identifing the dysesthetic neuropathic pain often seen in SCI. Localized single-voxel (8-cm(3) volume) proton spectra were acquired from the left and right thalami. RESULTS: The concentration of N-acetyl (NA) was negatively correlated with pain intensity (r = -0.678), and the t test showed that NA was significantly different between patients with pain and patients without pain (P =.006). Myo-inositol was positively correlated with pain intensity (r = 0.520); difference between patients with pain and those without pain was almost significant (P =.06). CONCLUSION: The observed differences in metabolites in SCI patients with and pain and in those without pain suggest anatomic, functional, and biochemical changes in the thalamic region.

Methods to measure sensory function in humans versus animals.

Sensation is perhaps one of the most complex senses. It allows us to experience our environment, and it provides ongoing feedback for the performance of accurate motor tasks. The present methods used for clinical testing of sensation in patients with spinal cord injury (SCI) rely on traditional techniques developed many years ago. This type of testing has been incorporated into the ASIA (American Spinal Injury Association) score, which has become the principal instrument for measuring the recovery of sensory function in humans. Unfortunately, the ASIA score lacks sophistication and is not quantitative. Similar shortcomings are found in the testing of sensation in experimental animal models of SCI. Although highly refined methods have been developed for the study of sensation and pain perception in animals, these methods have not been incorporated for measuring recovery of function in experimental SCI. A review of the available literature suggests that further refined and quantifiable tests need to be developed in this area.

Metabolite concentrations in the anterior cingulate cortex predict high neuropathic pain impact after spinal cord injury.

Persistent pain is a common reason for reduced quality of life after a spinal cord injury (SCI). Biomarkers of neuropathic pain may facilitate translational research and the understanding of underlying mechanisms. Research suggests that pain and affective distress are anatomically and functionally integrated in the anterior cingulate cortex and can modulate sensory and affective aspects of pain. We hypothesized that severe neuropathic pain with a significant psychosocial impact would be associated with metabolite concentrations (obtained by magnetic resonance spectroscopy) in the anterior cingulate cortex, indicating neuronal and/or glial dysfunction. Participants with SCI and severe, high-impact neuropathic pain (SCI-HPI; n=16), SCI and moderate, low-impact neuropathic pain (SCI-LPI; n=24), SCI without neuropathic pain (SCI-noNP; n=14), and able-bodied, pain-free control subjects (A-B; n=22) underwent a 3-T magnetic resonance imaging brain scan. Analyses revealed that the SCI-HPI group had significantly higher levels of myoinositol (Ins) (P<.000), creatine (P=.007), and choline (P=.014), and significantly lower levels of N-acetyl aspartate/Ins (P=.024) and glutamate-glutamine (Glx)/Ins (P=.003) ratios than the SCI-LPI group. The lower Glx/Ins ratio significantly discriminated between SCI-HPI and the A-B (P=.006) and SCI-noNP (P=.026) groups, displayed excellent test-retest reliability, and was significantly related to greater pain severity, interference, and affective distress. This suggests that the combination of lower glutamatergic metabolism and proliferation of glia and glial activation are underlying mechanisms contributing to the maintenance of severe neuropathic pain with significant psychosocial impact in chronic SCI. These findings indicate that the Glx/Ins ratio may be a useful biomarker for severe SCI-related neuropathic pain with significant psychosocial impact.

Decreased spinothalamic and dorsal column medial lemniscus-mediated function is associated with neuropathic pain after spinal cord injury.

Neuropathic pain (NP) after spinal cord injury (SCI) can significantly and negatively affect quality of life and is often refractory to currently available treatments. In order to find more effective therapeutic avenues, it would be helpful to identify the primary underlying pathophysiological mechanisms in each individual. The aim of the present study was to assess the relationship between the presence and severity of NP after SCI and measures of somatosensory function mediated via the dorsal column medial lemniscal (DCML) pathway and the spinothalamic tract (STT). Vibratory, mechanical, thermal, and pain thresholds measured in areas at and below the neurological level of injury (LOI) in persons with SCI and NP (SCI-NP, n=47) and in persons with SCI without NP (SCI-noNP, n=18) were normalized to data obtained from able-bodied pain-free control subjects (A-B, n=30). STT-mediated function at and below the LOI was significantly impaired in both SCI groups compared with A-B controls (p<0.001), but not significantly different between the two SCI groups (NP vs. no-NP). In contrast, the SCI-NP group had significantly greater impairment of DCML-mediated function at the LOI, as reflected by greater vibratory detection deficits (z=-3.89±0.5), compared with the SCI-noNP group (z=-1.95±0.7, p=0.034). Within the SCI-NP group, NP severity was significantly associated with increased thermal sensitivity below the LOI (r=0.50, p=0.038). Our results suggest that both impaired STT and DCML-mediated function are necessary for the development of NP after SCI. However, within the SCI-NP group, greater NP severity was associated with greater sensitivity to thermal stimuli below the LOI. This finding concurs with other studies suggesting that STT damage with some sparing is associated with NP.

Internal consistency, stability, and validity of the spinal cord injury version of the multidimensional pain inventory.

OBJECTIVE: To evaluate the internal consistency, stability, and construct validity of a spinal cord injury (SCI) version of the Multidimensional Pain Inventory (MPI-SCI). DESIGN: Interview. SETTING: Veterans Affairs medical center and university-based institute. PARTICIPANTS: Community sample of persons with SCI and chronic pain (N=161). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The MPI-SCI. RESULTS: The internal consistency of the MPI-SCI subscales ranged from fair (.60) for affective distress to substantial (.94) for pain interference with activities. The subscales of the MPI-SCI (ie, life interference [r=.81], affective distress [r=.71], solicitous responses [r=.86], distracting responses [r=.85], general activity [r=.69], pain interference with activities [r=.78], pain severity [r=.69], negative responses [r=.69]) showed adequate stability. In contrast, the stability of the support (r=.59) and the life control subscales (r=.31) was unacceptably low. All MPI-SCI subscales with the exception of the perceived responses by significant others subscales showed good convergent, discriminant, and concurrent validity. CONCLUSIONS: The MPI-SCI appears to be a reasonable measure for evaluating chronic pain impact after SCI. In clinical trials, however, supplementary instruments should be included to assess changes in affect, social support, and perceptions of life control.

Chronicity of pain associated with spinal cord injury: A longitudinal analysis.

This study determined the stability of self-reported clinical pain characteristics and pain-induced interference with sleep and daily activities in people with spinal cord injury. The study followed up a previous survey that identified clinical pain patterns (i.e., neuropathic pain below the level of injury; upper-limb pain in tetraplegia; and severe, persistent pain). A confirmatory factor analysis (CFA) of the present study's data confirmed the previously observed pain patterns. The CFA also confirmed positive correlations between the surveys on individual pain characteristics (i.e., number of pain locations [r = 0.63, p < 0.001], number of descriptors [r = 0.61, p < 0.001], pain intensity [r = 0.68, p < 0.001], and temporal aspects [r = 0.47, p < 0.001]). Despite an overall stable clinical picture of pain, "aching" pain (p < 0.001) and sleep interference caused by pain (p < 0.001) significantly increased over time.