A comparison of the SF-36 and Nottingham Health Profile in patients with chronic neuropathic pain

Spinal Cord Stimulation Alleviates Neuropathic Pain by Attenuating Microglial Activation via Reducing Colony-Stimulating Factor 1 Levels in the Spinal Cord in a Rat Model of Chronic Constriction Injury

BACKGROUND

Spinal cord stimulation (SCS) is an emerging, minimally invasive procedure used to treat patients with intractable chronic pain conditions. Although several signaling pathways have been proposed to account for SCS-mediated pain relief, the precise mechanisms remain poorly understood. Recent evidence reveals that injured sensory neuron-derived colony-stimulating factor 1 (CSF1) induces microglial activation in the spinal cord, contributing to the development of neuropathic pain (NP). Here, we tested the hypothesis that SCS relieves pain in a rat model of chronic constriction injury (CCI) by attenuating microglial activation via blocking CSF1 to the spinal cord.

METHODS

Sprague-Dawley rats underwent sciatic nerve ligation to induce CCI and were implanted with an epidural SCS lead. SCS was delivered 6 hours per day for 5 days. Some rats received a once-daily intrathecal injection of CSF1 for 3 days during SCS.

RESULTS

Compared with naive rats, CCI rats had a marked decrease in the mechanical withdrawal threshold of the paw, along with increased microglial activation and augmented CSF1 levels in the spinal dorsal horn and dorsal root ganglion, as measured by immunofluorescence or Western blotting. SCS significantly increased the mechanical withdrawal threshold and attenuated microglial activation in the spinal dorsal horn in CCI rats, which were associated with reductions in CSF1 levels in the spinal dorsal horn and dorsal roots but not dorsal root ganglion. Moreover, intrathecal injection of CSF1 completely abolished SCS-induced changes in the mechanical withdrawal threshold and activation of microglia in the spinal dorsal horn in CCI rats.

CONCLUSIONS

SCS reduces microglial activation in the spinal cord and alleviates chronic NP, at least in part by inhibiting the release of CSF1 from the dorsal root ganglion ipsilateral to nerve injury.

Neuropathic pain modeling: Focus on synaptic and ion channel mechanisms

Animal models of pain consist of modeling a pain-like state and measuring the consequent behavior. The first animal models of neuropathic pain (NP) were developed in rodents with a total lesion of the sciatic nerve. Later, other models targeting central or peripheral branches of nerves were developed to identify novel mechanisms that contribute to persistent pain conditions in NP. Objective assessment of pain in these different animal models represents a significant challenge for pre-clinical research. Multiple behavioral approaches are used to investigate and to validate pain phenotypes including withdrawal reflex to evoked stimuli, vocalizations, spontaneous pain, but also emotional and affective behaviors. Furthermore, animal models were very useful in investigating the mechanisms of NP. This review will focus on a detailed description of rodent models of NP and provide an overview of the assessment of the sensory and emotional components of pain. A detailed inventory will be made to examine spinal mechanisms involved in NP-induced hyperexcitability and underlying the current pharmacological approaches used in clinics with the possibility to present new avenues for future treatment. The success of pre-clinical studies in this area of research depends on the choice of the relevant model and the appropriate test based on the objectives of the study.

An Adapted Chronic Constriction Injury of the Sciatic Nerve Produces Sensory, Affective, and Cognitive Impairments: A Peripheral Mononeuropathy Model for the Study of Comorbid Neuropsychiatric Disorders Associated with Neuropathic Pain in Rats

BACKGROUND

Chronic constriction injury (CCI) is a model of neuropathic pain induced by four loose ligatures around the sciatic nerve. This work aimed to investigate the sensory, affective, cognitive, and motor changes induced by an adaptation of the CCI model by applying a single ligature around the sciatic nerve.

METHODS

Mechanical allodynia was measured from day 1 to day 28 postsurgery by the von Frey test. The beam walking test (BWT) was conducted weekly until 28 days after surgery. Anxiety- and depression-like behaviors, and cognitive performance were assessed through the open field (OF), forced swimming (FS), and novel object recognition (NOR) tests, respectively, 21 days after surgery.

RESULTS

The two CCI models, both Bennett and Xie's model (four ligatures of the sciatic nerve) and a modification of it (one ligature), induced mechanical allodynia, increased immobility in the FS, and reduced recognition index in the NOR. The exploratory behavior and time spent in the central part of the arena decreased, while the defensive behavior increased in the OF. The animals subjected to the two CCI models showed motor alterations in the BWT; however, autotomy was observed only in the group with four ligatures and not in the group with a single ligature.

CONCLUSIONS

Overall these results demonstrate that our adapted CCI model, using a single ligature around the sciatic nerve, induces sensory, affective, cognitive, and motor alterations comparable to the CCI model with four ligatures without generating autotomy. This adaptation to the CCI model may therefore represent an appropriate and more easily performed model for inducing neuropathic pain and study underlying mechanisms and effective treatments.

CSF levels of apolipoprotein C1 and autotaxin found to associate with neuropathic pain and fibromyalgia

Objective

Neuropathic pain and fibromyalgia are two common and poorly understood chronic pain conditions that lack satisfactory treatments, cause substantial suffering and societal costs. Today, there are no biological markers on which to base chronic pain diagnoses, treatment choices or to understand the pathophysiology of pain for the individual patient. This study aimed to investigate cerebrospinal fluid (CSF) protein profiles potentially associated with fibromyalgia and neuropathic pain.

Methods

CSF samples were collected from 25 patients with neuropathic pain (two independent sets, n=14 patients for discovery, and n=11 for verification), 40 patients with fibromyalgia and 134 controls without neurological disease from two different populations. CSF protein profiling of 55 proteins was performed using antibody suspension bead array technology.

Results

We found increased levels of apolipoprotein C1 (APOC1) in CSF of neuropathic pain patients compared to controls and there was a trend for increased levels also in fibromyalgia patients. In addition, levels of ectonucleotide pyrophosphatase family member 2 (ENPP2, also referred to as autotaxin) were increased in the CSF of fibromyalgia patients compared to all other groups including patients with neuropathic pain.

Conclusion

The increased levels of APOC1 and ENPP2 found in neuropathic pain and fibromyalgia patients may shed light on the underlying mechanisms of these conditions. Further investigation is required to elucidate their role in maintaining pain and other main symptoms of these disorders.

Comparison between different instruments for measuring health-related quality of life in a population sample, the WHO MONICA Project, Gothenburg, Sweden: an observational, cross-sectional study

OBJECTIVE

The general aim was to meet the need for empirical comparative studies of health-related quality of life (HRQoL) assessment instruments, by evaluating and comparing the psychometric properties and results of three different, widely used, generic HRQoL instruments in a population sample. The specific aims were to evaluate the subscales of the different instruments that measure the same domain and to assess the association between the HRQoL measures and a single-item self-rated health scale.

DESIGN

An observational cross-sectional study.

SETTING

A population-based sample from Gothenburg, Sweden, was studied in 2008 in the WHO MONItoring of trends and determinants for CArdiovascular disease.

PARTICIPANTS

A total of 414 subjects were included, 77% women, age range 39-78 years.

INTERVENTIONS

The Nottingham Health Profile (NHP), the Short Form-36 questionnaire (SF-36), the Psychological General Well-Being Index (PGWB) and a self-rated health scale were used.

OUTCOME MEASURES

Scores were analysed for their psychometric properties, internal consistency (Cronbach's α), construct validity (Spearman's rank correlations and R2 coefficients) and discriminative ability for the presence of self-rated ill-health.

RESULTS

PGWB and SF-36 had higher Cronbach's α scores than NHP. All correlations calculated between the subscales that were conceptually similar were significant (p<0.01). All subscales could differentiate the presence of self-rated ill-health according to the self-rated health scale (p<0.001). The self-rated health scale correlated strongly with all of the three HRQoL instruments used.

CONCLUSIONS

There was a high concordance between the instruments within each domain that was conceptually similar. All three HRQoL instruments (PGWB, SF-36 and NHP) could discriminate the presence of self-rated ill-health. The simple and quick self-rated health scale correlated strongly with the more time-consuming PGWB, SF-36 and NHP. The result supports the existence of a strong association between the self-rated health scale and HRQoL in the general population.

The association between pregnancy, pelvic girdle pain and health-related quality of life - a comparison of two instruments

Background

The main purposes in this cross-sectional study were to study the impact of pregnancy and pelvic girdle pain (PGP) on health related quality of life (HRQoL), by comparing the scores on different domains of two HRQoL instruments in pregnant women with population norms as well as in women with severe and less severe PGP. Further, to explore the association between PGP and HRQoL and whether the two instruments differ in the way they assess the influence of PGP on HRQoL.

Methods

Pregnant women in gestation week 30 completed questionnaires containing the Short Form Health Survey (SF-36) and the Nottingham Health Profile (NHP). Additional variables, self-reported PGP, pain location in the pelvis and response on clinical tests were also collected. HRQoL scores were compared with expected age adjusted mean scores and comparisons between groups with different severity of PGP were made, using Mann-Whitney U, t-tests and Hodges-Lehman method.

Results

Two hundred eighty-three pregnant women, mean age 31.3 (SD 4.2) years, participated. We found statistical significant differences in all domains of both HRQoL instruments in late pregnancy compared to the expected age-adjusted means of the reference populations (p ≤ 0.003) except for Social isolation (p = 0.775). Women with PGP had lower HRQoL than women without, and the most affected women scored lowest. SF-36 detected a deficit in Social Function compared to norms whereas the NHP showed no evidence of Social Isolation.

Conclusions

Both instruments revealed changes in HRQoL in pregnant women compared with population norms. Pregnancy itself influences HRQoL and having PGP gave an additional impact. The consistency of the correlations between SF-36 and NHP domains across the sub-groups found in this study suggests convergent validity across levels of impairment. The results in social domains vary between SF-36 and NHP in pregnant women and might be due to the basic design (construction) of the tools.

Prevalence of central and peripheral neuropathic pain in patients attending pain clinics in Spain: factors related to intensity of pain and quality of life

Background

The objective of the study was to estimate the prevalence of pure central neuropathic pain (CNP) and peripheral neuropathic pain (PNP) among patients attending pain clinics in Spain. The study also aimed to analyze factors associated with pain intensity and quality of life (QoL).

Methods

A cross-sectional study was performed including 53 patients with pure CNP and 281 with pure PNP attending in 104 pain clinics in Spain. The revised grading system proposed in 2008 to determine a definite, probable or possible diagnosis of NP was used. Pain features, psychological variables and QoL were assessed. Descriptive, bivariate and multivariate analyses were performed.

Results

The prevalence of pure CNP and PNP amongst neuropathic pain patients was 2.4% (95% CI: 1.7;3.1) and 12.9% (95% CI: 1.5;14.3), respectively. Comorbid anxiety, depression or sleep disorders were high in both groups, but higher in CNP patients (51.1%, 71.4%, respectively). Pain intensity in PNP patients was associated with the presence of depression and sleep disturbances. However, in CNP patients, it was related with pain in the lower limbs. The impairment of QoL was greater in CNP patients than in PNP patients; pain location, presence of depression and sleep disturbance were the factors that most negatively affected QoL. Among PNP patients, women and those with higher pain intensity had worse QoL.

Conclusion

Pain intensity and QoL are affected by different factors in patients suffering from CNP or PNP. Identifying these factors could serve to guide therapeutic strategies and improve the QoL of patients.

A Review of the Emotional Aspects of Neuropathic Pain: From Comorbidity to Co-Pathogenesis

Neuropathic pain is characterized by both sensory and affective disturbances, supporting the notion that pain and mood disorders share common pathogenetic mechanisms. Moreover, biological and neuroimaging data show that common brain areas are involved in the modulation of painful and emotional experiences. Improved understanding of the molecular mechanisms underlying the role of neuroinflammation in regulation of affective behavior in neuropathic pain states is important for the development of novel therapeutic strategies. Psychological issues must be considered a factor influencing treatment and outcome in patients with neuropathic pain.

Funding: Pfizer, Italy.

Non-invasive brain stimulation interventions for management of chronic central neuropathic pain: a scoping review protocol

INTRODUCTION

Pain can affect people regardless of age, gender or ethnicity. Chronic central neuropathic pain (CCNP) is a debilitating condition that affects populations such as stroke survivors, amputees, spinal cord injury patients and patients with multiple sclerosis, with prevalence rates between 30% and 80%. This condition can be caused by a lesion or disease affecting the somatosensory system. CCNP is notoriously drug resistant, and few effective CCNP treatment or management strategies exist. The emergence of non-invasive brain stimulation and neuromodulation techniques provide novel avenues for managing chronic central neuropathic pain. This scoping review aims to systematically identify the methods and effectiveness of non-invasive brain stimulation techniques for treating and managing chronic central neuropathic pain.

METHODS AND ANALYSIS

The following databases will be searched systematically: PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Institute of Electric and Electronic Engineers (IEEE), Association of Computing Machinary (ACM) and Scopus. Additional literature will be identified by searching the reference lists of identified studies. Studies will include reviews and original research in both published and grey literatures. Two reviewers will independently screen identified studies for final inclusion. A quantitative analysis on the intervention type, application and efficacy will be synthesised along with a qualitative analysis to describe the effectiveness of each intervention.

ETHICS AND DISSEMINATION

No primary data will be collected and hence formal ethics review is not required. The results of the scoping review will be presented at relevant national and international conferences, published in a peer-reviewed journal and provided to the stakeholders with plain language to be posted on their websites. This scoping review will provide a foundation to guide the development of future primary research on non-invasive brain stimulation and CCNP.

Neuropathic pain's biopsychosocial effects

The aim of our study is to understand neuropathic pain's social, psychological, and biological effects on the patients. All of the patients who were diagnosed with neuropathic pain (NP) by a neurologist were invited to participate in the study. The diagnoses were made based on the patients' history and symptoms and the results of their neurological examinations. Demographic characteristics (age and pain duration), diagnoses, and medical histories of the patients were recorded. Average daily pain intensity was measured using a 100-mm visual analogue scale (VAS). Quality of life was measured with RAND 36-Item Health Survey 1.0. Pittsburgh Sleep Quality Index (PSQI) was used to examine the quality of sleep, and Beck Depression Scale was used to examine depression status of the patients. A total of 26 patients (14 male, 12 female) between 33 and 79 years of age participated in the study. There were no dropouts from the study. Eleven (42.3%) patients' mood was normal and the others (57.7%) had different levels of depression. Two patients' (7.7%) quality of sleep was normal, but 24 (92.3%) of the patients' quality of sleep was poor. The patients' pain intensity was at an important and high value (VAS: 6.88). The most important result of this clinical study was that the biopsychosocial approach would be appropriate to understand and treat NP. The biopsychosocial approach to pain addresses psychological, sociocultural factors, and biomedical/physiological aspects. We wanted to draw attention to NP's psychological, emotional and sociocultural characteristics to show that the NP treatment can be applied within this framework.

Does Neuropathic Pain Affect the Quality of Sleep?

OBJECTIVE

We aimed to evaluate the quality of sleep (QoS) in patients with neuropathic pain (NP) and to investigate the association between possible QoS impairment and NP characteristics.

MATERIALS AND METHODS

Patients with NP and controls were examined. Age, sex, NP duration, NP cause (central, peripheral, or mixed), and pain intensity (with a Likert-type scale and visual analog scale) were recorded. NP was screened with Douleur Neuropathique 4 questions (DN4), and QoS was evaluated using the Pittsburg Sleep Quality Index (PSQI). Mann-Whitney U test and regression analysis were performed to evaluate the data.

RESULTS

Seventy patients with NP and 30 age- and sex-matched controls were included. The mean age of the patients and controls were 45.04±10.21 years and 39.00±19.23 years, respectively. Significantly higher scores of sleep latency (p=0.002), sleep duration (p=0.003), sleep efficiency (p=0.002), sleep disturbance (p<0.000), daytime dysfunction (p=0.04), and PSQI total were observed in patients with NP than in controls (p<0.000). In addition, 80% of patients with NP and 37 % of controls were classified as having poor QoS (p<0.000). Female sex, pain intensity, and NP duration were found to be factors related to having poor QoS in patients with NP (p=0.026, p=0.006, and p<0.000, respectively).

CONCLUSION

In our study, 80% of patients with NP had poor QoS regardless of the NP cause. Female sex, pain severity, and NP duration were found to be factors correlated with poor QoS. Treatment strategies that target not only NP itself but also better QoS may contribute to the overall success of management.

Quality of life and functional capacity are adversely affected in osteoarthritis patients with neuropathic pain

The aim of this study was to examine the neuropathic pain component of knee osteoarthritis (OA) patients and to investigate the relationship between neuropathic pain, disease stage, functional state, depression, anxiety, and quality of life. This study included 60 patients with knee OA. All demographic data and radiological results were recorded. Visual Analog Scale (VAS), Timed Up and Go Test, Chair Stand Test, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), PainDETECT questionnaire, DN4 questionnaire, Short form-36 questionnaire, and Hospital Anxiety Depression Scale were performed for each patient. Neuropathic pain was detected in 66.7% of patients based on the PainDETECT scale and in 46.7% of patients based on DN4 scale. VAS-resting, OA grade, WOMAC scores, and SF-scores showed a significant difference in patients that detected neuropathic pain with PainDETECT (p<0.05). Based on the DN4 scale, patients with neuropathic pain had significantly higher WOMAC scores and significantly lower SF-36 scores (p<0.05). The PainDETECT questionnaire scores showed positive correlations with Timed Up-and-go Test, VAS-resting, WOMAC scores, Hospital Anxiety Depression Scale scores, and a negative correlation with all SF-36 scores (p<0.05). DN4 questionnaire scores showed a negative correlation with SF-36 scores and positive correlation with WOMAC scores (p<0.05). To conclude, it should be kept in mind that patients with knee OA who describe intense pain may have a neuropathic component involved in the clinical condition. Quality of life and functional capacity are adversely affected in patients with knee OA who have neuropathic pain. This should be taken into account while planning the treatment of these patients.

Most common problems across health conditions as described by the International Classification of Functioning, Disability, and Health

Health conditions are associated with a variety of functional outcomes. Even though functional outcomes are diverse for different health conditions, they can have important commonalities. The aim of this study was to identify the most common problems in functioning across the wide range of health conditions using the International Classification of Functioning (ICF). Existing databases created for the 21 ICF Core Sets studies were descriptively analyzed. These included data collected in 44 countries on 9978 patients with one of 21 health conditions as the main diagnosis. A frequency cutoff of 50% was used to identify the most common problems in functioning when looking at single health conditions and across them. No category was identified as common to all health conditions included in the study. Fifteen most frequent categories were common in 10 to 13 health conditions out of 21. Eleven categories correspond to the list of activities and participation, and four to the list of body functions. These are related to mobility, daily routine, mental functions, intimate relations, employment, and leisure. Some health conditions have more commonalities between each other. The most common problems across health conditions are therefore related to mental functions, mobility, daily life, intimate relations, employment, and leisure. The results contribute toward the identification of the universal set of ICF categories that can be used in clinical practice for the general assessment of functioning.

Animal models of chronic pain: Advances and challenges for clinical translation

Chronic pain is a global problem that has reached epidemic proportions. An estimated 20% of adults suffer from pain, and another 10% are diagnosed with chronic pain each year (Goldberg and McGee, ). Despite the high prevalence of chronic pain (an estimated 1.5 billion people are afflicted worldwide), much remains to be understood about the underlying causes of this condition, and there is an urgent requirement for better pain therapies. The discovery of novel targets and the development of better analgesics rely on an assortment of preclinical animal models; however, there are major challenges to translating discoveries made in animal models to realized pain therapies in humans. This review discusses common animal models used to recapitulate clinical chronic pain conditions (such as neuropathic, inflammatory, and visceral pain) and the methods for assessing the sensory and affective components of pain in animals. We also discuss the advantages and limitations of modeling chronic pain in animals as well as highlighting strategies for improving the predictive validity of preclinical pain studies. © 2016 Wiley Periodicals, Inc.

Quality of life increases in patients with painful diabetic neuropathy following treatment with spinal cord stimulation

Purpose

This study aims to explore the changes in pain intensity and quality of life (QoL) experienced by patients with painful diabetic neuropathy (PDN) treated with spinal cord stimulation (SCS) and conventional medical practice (CMP).

Methods

Patient-reported pain intensity and QoL data were obtained from participants in an international multicentre randomised controlled trial comparing SCS versus CMP. Data were collected at randomisation and 6 month follow up by means of a visual analogue scale for pain intensity, the EuroQoL Visual Analogue Scale (EQ VAS) and the EuroQol EQ-5D index. Quality-adjusted life years (QALYs) were calculated for each treatment using the ‘area under the curve’ method. Differences in QALYs were calculated after adjusting for between-treatment imbalances in baseline QoL.

Results

At 6 months, patients allocated to SCS reported larger reductions in pain intensity and improvements in QoL measured by the EQ-5D utility score and EQ VAS as compared to those allocated to CMP. Initial calculations of QALYs for the SCS and CMP groups suggested no statistical differences between the groups. Adjusting for imbalances in baseline EQ-5D scores showed SCS to be associated with significantly higher QALYs compared to CMP.

Conclusions

SCS resulted in significant improvement in pain intensity and QoL in patients with PDN, offering further support for SCS as an effective treatment for patients suffering from PDN. From a methodological point of view, different results would have been obtained if QALY calculations were not adjusted for baseline EQ-5D scores, highlighting the need to account for imbalances in baseline QoL.

Chronic Constriction Injury of the Rat's Infraorbital Nerve (IoN-CCI) to Study Trigeminal Neuropathic Pain

Animal models are important tools to study the pathophysiology and pharmacology of neuropathic pain. This manuscript describes the surgical and behavioral procedures to study trigeminal neuropathic pain in rats. To meet the specificity of trigeminal neuropathic pain syndromes, the infraorbital nerve (IoN) is subjected to a chronic constriction injury (CCI) by loosely ligating the nerve. An intra-orbital approach is presented here to expose and ligate the IoN in the orbital cavity. After IoN ligation, rats exhibit changes in spontaneous behavior and in response to von Frey hair stimulation that are indicative of persistent pain and mechanical allodynia. Two phases can be defined in the development of the behavioral changes. During the first week following IoN-CCI (phase 1), rats show an increased and asymmetric face grooming activity, i.e., with face wash strokes primarily directed to the nerve-injured IoN territory. A distinction is made between face grooming behavior that is part of a more general body grooming behavior, which remains largely unaffected by IoN-CCI, and face grooming that is neither preceded nor followed by body grooming, which is significantly increased after IoN-CCI. During this period, responsiveness to mechanical stimulation of the IoN territory is reduced. This hyporesponsiveness is abruptly replaced by an extreme hyperresponsiveness whereby even very weak stimulus intensities provoke nocifensive behavior (phase 2). The phenomenological similarities between these behavioral alterations and reported signs of facial pain (i.e., responses to noxious stimulation of the face) suggest the presence of dysesthesia/paresthesia and mechanical allodynia in the ligated IoN territory.

Recruitment of dorsal midbrain catecholaminergic pathways in the recovery from nerve injury evoked disabilities

BACKGROUND

The periaqueductal gray region (PAG) is one of several brain areas identified to be vulnerable to structural and functional change following peripheral nerve injury. Sciatic nerve constriction injury (CCI) triggers neuropathic pain and three distinct profiles of changes in complex behaviours, which include altered social and sleep-wake behaviours as well as changes in endocrine function. The PAG encompasses subgroups of the A10 dopaminergic and A6 noradrenergic cell groups; the origins of significant ascending projections to hypothalamic and forebrain regions, which regulate sleep, complex behaviours and endocrine function. We used RT-PCR, western blots and immunohistochemistry for tyrosine hydroxylase to determine whether (1) tyrosine hydroxylase increased in the A10/A6 cells and/or; (2) de novo synthesis of tyrosine hydroxylase, in a 'TH-naïve' population of ventral PAG neurons characterized rats with distinct patterns of behavioural and endocrine change co-morbid with CCI evoked-pain.

RESULTS

Evidence for increased tyrosine hydroxylase transcription and translation in the constitutive A10/A6 cells was found in the midbrain of rats that showed an initial 2-3 day post-CCI, behavioural and endocrine change, which recovered by days 5-6 post-CCI. Furthermore these rats showed significant increases in the density of TH-IR fibres in the vPAG.

CONCLUSIONS

Our data provide evidence for: (1) potential increases in dopamine and noradrenaline synthesis in vPAG cells; and (2) increased catecholaminergic drive on vPAG neurons in rats in which transient changes in social behavior are seen following CCI. The data suggests a role for dopaminergic and noradrenergic outputs, and catecholaminergic inputs of the vPAG in the expression of one of the profiles of behavioural and endocrine change triggered by nerve injury.

Chronic pain patients' treatment preferences: a discrete-choice experiment

OBJECTIVE

The objective of this study was to identify, document, and weight attributes of a pain medication that are relevant from the perspective of patients with chronic pain. Within the sub-population of patients suffering from "chronic neuropathic pain", three groups were analyzed in depth: patients with neuropathic back pain, patients with painful diabetic polyneuropathy, and patients suffering from pain due to post-herpetic neuralgia. The central question was: "On which features do patients base their assessment of pain medications and which features are most useful in the process of evaluating and selecting possible therapies?"

METHODS

A detailed literature review, focus groups with patients, and face-to-face interviews with widely recognized experts for pain treatment were conducted to identify relevant treatment attributes of a pain medication. A pre-test was conducted to verify the structure of relevant and dominant attributes using factor analyses by evaluating the most frequently mentioned representatives of each factor. The Discrete-Choice Experiment (DCE) used a survey based on self-reported patient data including socio-demographics and specific parameters concerning pain treatment. Furthermore, the neuropathic pain component was determined in all patients based on their scoring in the painDETECT(®) questionnaire. For statistical data analysis of the DCE, a random effect logit model was used and coefficients were presented.

RESULTS

A total of 1,324 German patients participated in the survey, of whom 44 % suffered from neuropathic back pain (including mixed pain syndrome), 10 % complained about diabetic polyneuropathy, and 4 % reported pain due to post-herpetic neuralgia. A total of 36 single quality aspects of pain treatment, detected in the qualitative survey, were grouped in 7 dimensions by factor analysis. These 7 dimensions were used as attributes for the DCE. The DCE model resulted in the following ranking of relevant attributes for treatment decision: "no character change", "less nausea and vomiting", "pain reduction" (coefficient: >0.9 for all attributes, "high impact"), "rapid effect", "low risk of addiction" (coefficient ~0.5, "middle impact"), "applicability with comorbidity" (coefficient ~0.3), and "improvement of quality of sleep" (coefficient ~0.25). All attributes were highly significant (p < 0.001).

CONCLUSIONS

The results were intended to enable early selection of an individualized pain medication. The results of the study showed that DCE is an appropriate means for the identification of patient preferences when being treated with specific pain medications. Due to the fact that pain perception is subjective in nature, the identification of patients´ preferences will enable therapists to better develop and implement patient-oriented treatment of chronic pain. It is therefore essential to improve the therapists´ understanding of patient preferences in order to make decisions concerning pain treatment. DCE and direct assessment should become valid instruments to elicit treatment preferences in chronic pain.

Evidence for a distinct neuro-immune signature in rats that develop behavioural disability after nerve injury

BACKGROUND

Chronic neuropathic pain is a neuro-immune disorder, characterised by allodynia, hyperalgesia and spontaneous pain, as well as debilitating affective-motivational disturbances (e.g., reduced social interactions, sleep-wake cycle disruption, anhedonia, and depression). The role of the immune system in altered sensation following nerve injury is well documented. However, its role in the development of affective-motivational disturbances remains largely unknown. Here, we aimed to characterise changes in the immune response at peripheral and spinal sites in a rat model of neuropathic pain and disability.

METHODS

Sixty-two rats underwent sciatic nerve chronic constriction injury (CCI) and were characterised as either Pain and disability, Pain and transient disability or Pain alone on the basis of sensory threshold testing and changes in post-CCI dominance behaviour in resident-intruder interactions. Nerve ultrastructure was assessed and the number of T lymphocytes and macrophages were quantified at the site of injury on day six post-CCI. ATF3 expression was quantified in the dorsal root ganglia (DRG). Using a multiplex assay, eight cytokines were quantified in the sciatic nerve, DRG and spinal cord.

RESULTS

All CCI rats displayed equal levels of mechanical allodynia, structural nerve damage, and reorganisation. All CCI rats had significant infiltration of macrophages and T lymphocytes to both the injury site and the DRG. Pain and disability rats had significantly greater numbers of T lymphocytes. CCI increased IL-6 and MCP-1 in the sciatic nerve. Examination of disability subgroups revealed increases in IL-6 and MCP-1 were restricted to Pain and disability rats. Conversely, CCI led to a decrease in IL-17, which was restricted to Pain and transient disability and Pain alone rats. CCI significantly increased IL-6 and MCP-1 in the DRG, with IL-6 restricted to Pain and disability rats. CCI rats had increased IL-1β, IL-6 and MCP-1 in the spinal cord. Amongst subgroups, only Pain and disability rats had increased IL-1β.

CONCLUSIONS

This study has defined individual differences in the immune response at peripheral and spinal sites following CCI in rats. These changes correlated with the degree of disability. Our data suggest that individual immune signatures play a significant role in the different behavioural trajectories following nerve injury, and in some cases may lead to persistent affective-motivational disturbances.

Injury-Dependent and Disability-Specific Lumbar Spinal Gene Regulation following Sciatic Nerve Injury in the Rat

Allodynia, hyperalgesia and spontaneous pain are cardinal sensory signs of neuropathic pain. Clinically, many neuropathic pain patients experience affective-motivational state changes, including reduced familial and social interactions, decreased motivation, anhedonia and depression which are severely debilitating. In earlier studies we have shown that sciatic nerve chronic constriction injury (CCI) disrupts social interactions, sleep-wake-cycle and endocrine function in one third of rats, a subgroup reliably identified six days after injury. CCI consistently produces allodynia and hyperalgesia, the intensity of which was unrelated either to the altered social interactions, sleep-wake-cycle or endocrine changes. This decoupling of the sensory consequences of nerve injury from the affective-motivational changes is reported in both animal experiments and human clinical data. The sensory changes triggered by CCI are mediated primarily by functional changes in the lumbar dorsal horn, however, whether lumbar spinal changes may drive different affective-motivational states has never been considered. In these studies, we used microarrays to identify the unique transcriptomes of rats with altered social behaviours following sciatic CCI to determine whether specific patterns of lumbar spinal adaptations characterised this subgroup. Rats underwent CCI and on the basis of reductions in dominance behaviour in resident-intruder social interactions were categorised as having Pain & Disability, Pain & Transient Disability or Pain alone. We examined the lumbar spinal transcriptomes two and six days after CCI. Fifty-four ‘disability-specific’ genes were identified. Sixty-five percent were unique to Pain & Disability rats, two-thirds of which were associated with neurotransmission, inflammation and/or cellular stress. In contrast, 40% of genes differentially regulated in rats without disabilities were involved with more general homeostatic processes (cellular structure, transcription or translation). We suggest that these patterns of gene expression lead to either the expression of disability, or to resilience and recovery, by modifying local spinal circuitry at the origin of ascending supraspinal pathways.

Experiences with spinal cord stimulator in patients with chronic neuropathic back pain

Neuropathic pain is a complex, chronic, and disabling condition that has physical, functional, and psychosocial repercussions. Although the estimated prevalence of neuropathic pain in the general population ranges from 1.5% to 8%, neuropathic pain is frequently underdiagnosed and undertreated. The aims of this study were to examine the experience of patients treated with spinal cord stimulation as a pain-relieving treatment and how this may influence the patient's ability to participate in everyday life activities. A qualitative approach based on seven telephone interviews was performed. The participants were recruited from a university hospital in Norway, and all used spinal cord stimulation as a pain-relieving treatment. Qualitative content analysis was used. Two thematic findings emerged: (1) pain relief with spinal cord stimulation as a complex and individual experience and (2) challenges in adaptations in everyday life with spinal cord stimulation. Findings indicate that spinal cord stimulation can offer pain relief that can help patients achieve a meaningful life despite chronic pain. Spinal cord stimulation also may have disadvantages that should be considered before offering this treatment. It seems evident that extended information needs about working mechanism of SCS and precautions as well as follow-up are required to meet unexpected challenges in adaptation. Here the nurse has an important role when informing and following this patient group.

Assessment of quality of life in haemodialysis patients: a comparison of the Nottingham Health Profile and the Short Form 36

This study aimed to compare the psychometric properties of the Nottingham Health Profile (NHP) and the Medical Outcomes Study Short Form Health Survey (SF-36), which evaluates health-related quality of life in haemodialysis patients. Data were gathered using the NHP and the SF-36. Quality of life scores obtained from the NHP and the SF-36 were compared according to sociodemographic characteristics. It was found that the internal consistency values of the NHP and the SF-36 were similar. The floor effect of the two NHP subscales and the ceiling effect of all the NHP subscales were higher than those pertaining to the. It was observed that the NHP mean subscale scores were higher than those of the SF-36, except for one subscale of the SF-36. There was a significant positive correlation between the similar subscales of the NHP and the SF-36 and between the total scores. These results seem to support the utility of the NHP and the SF-36 in evaluating quality of life in haemodialysis patients.

Coping strategies and depressiveness in primary systemic vasculitis--what is their impact on health-related quality of life?

OBJECTIVE

To investigate the influence of disease-related coping strategies and depressiveness on health-related quality of life (HRQOL) in primary systemic vasculitis (PSV) patients.

METHODS

One hundred and twenty-two patients with definite diagnosis of PSV were examined in a cross-sectional study. HRQOL (SF-36), depressiveness (BDI), illness perception (B-IPQ) and coping strategies (FKV-LIS) were measured using validated instruments. Additional disease-related and demographic data were retrieved from the patients' records.

RESULTS

HRQOL in PSV patients was reduced compared with the SF-36 norm sample. Specific organ manifestation, size of vessel involvement and disease activity were not related to HRQOL. Linear regression modelling revealed a questionable relationship of emotional to physical HRQOL (P = 0.003, potential suppression effect of BDI), whereas both domains were influenced by depressiveness (P ≤ 0.001). Physical HRQOL was additionally related to fatigue and widowed marital status, while emotional HRQOL was associated with a depressive coping style.

CONCLUSION

HRQOL is impaired in PSV as compared with the general population. Current depressiveness strongly affects physical as well as mental HRQOL. Cognitive intervention strategies should be established in order to improve quality of life in PSV patients.

Cross-sectional evaluation of patient functioning and health-related quality of life in patients with neuropathic pain under standard care conditions

AIM

The purpose of this cross-sectional evaluation was to determine the impact of neuropathic pain (NeP) on patient functioning and Health-Related Quality of Life (HRQoL) under standard care conditions.

METHODS

Patients with NeP or neuropathic and nociceptive pain [Mixed Pain (MP)] enrolled in the DONEGA study, a naturalistic, prospective and multi-centre study of the effectiveness of gabapentin under usual care conditions, were included in this cross-sectional evaluation before starting study treatments. Participants completed the Short Form-McGill Pain Questionnaire, MOS Short Form-12 (SF-12), and Sheehan Disability Scale (ShDS). Multivariate analysis and regression models were used to analyze patient data.

RESULTS

A total of 1519 patients [mean+/-SD; 56.0+/-13.7 yrs old (58.8% female)] with NeP or MP were enrolled in the study. The mean pain history was 1.1+/-2.8 yrs, current pain intensity on a 5-point visual analogue scale was 2.8+/-1.0 and mean pain in previous week was 71.3+/-19.0mm. Pain substantially interfered (i.e., score > or = 5 on 0-10 scale) with normal work (5.9+/-3.0), social life (5.7+/-3.0), and family life (5.3+/-3.0), producing substantial disability (total ShDS score of 16.9+/-8.3 pts). Country-standardised physical (PCS) and mental health (MCS) component summary scores of SF-12 indicated significant impairment in both domains compared with the general Spanish population: PCS; -1.13+/-1.0 SDS (standard deviation score), and MCS; -1.21+/-0.7 SDS, equivalent to the 15th and 25th percentiles of normative populations, respectively.

CONCLUSIONS

Under standard care conditions, neuropathic and mixed pain are associated with impaired physical and mental QoL, producing a substantial level of disability in these patients.

Pharmacological treatment of neuropathic cancer pain: a comprehensive review of the current literature

Neuropathic cancer pain (NCP), commonly encountered in clinical practice, may be cancer-related, namely resulting from nervous system tumor invasion, surgical nerve damage during tumor removal, radiation-induced nerve damage and chemotherapy-related neuropathy, or may be of benign origin, unrelated to cancer. A neuropathic component is evident in about 1/3 of cancer pain cases. Although from a pathophysiological perspective NCP may differ from chronic neuropathic pain (NP), such as noncancer-related pain, clinical practice, and limited publications have shown that these two pain entities may share some treatment modalities. For example, co-analgesics have been well integrated into cancer pain-management strategies and are often used as First-Line options for the treatment of NCP. These drugs, including antidepressants and anticonvulsants, are recommended by evidence-based guidelines, whereas, others such as lidocaine patch 5%, are supported by randomized, controlled, clinical data and are included in guidelines for restricted conditions treatment. The vast majority of these drugs have already been proven useful in the management of benign NP syndromes. Treatment decisions for patients with NP can be difficult. The intrinsic difficulties in performing randomized controlled trials in cancer pain have traditionally justified the acceptance of drugs already known to be effective in benign NP for the management of malignant NP, despite the lack of relevant high quality data. Interest in NCP mechanisms and pharmacotherapy has increased, resulting in significant mechanism-based treatment advances for the future. In this comprehensive review, we present the latest knowledge regarding NCP pharmacological management.

Early experience with a brief, multimodal, multidisciplinary treatment program for fibromyalgia

Fibromyalgia is a complex heterogeneous disorder for which a multidisciplinary individualized approach is currently advocated. We executed a 1-week multidisciplinary fibromyalgia clinical program with seven patients, based on our experience with our existing 1.5-day multidisciplinary fibromyalgia program that has demonstrated both short- and long-term benefits. The current expanded program was not designed as a clinical study, but rather as a clinical feasibility assessment, and it was multidisciplinary in nature, with cognitive behavioral therapy, activity pacing, and graded exercise therapy as major components. We assessed changes in individual patients at 1 week and 3 months after the program with the use of validated self-report measures of pain, fatigue, and self-efficacy. All patients indicated at least small improvements in pain and physical symptoms at both 1 week and 3 months, and all but one patient showed improvement in self-efficacy at 1 week and 3 months. Similar trends were observed for fatigue. Based on our early clinical experience, we conclude that the 1-week multidisciplinary fibromyalgia program is logistically feasible and has potential for clinical efficacy. Further research is needed and is planned to test the clinical efficacy of this program and compare it with other interventions.

Neuropathic pain in patients with upper-extremity nerve injury

PURPOSE

The purpose of this review was to present an analysis of the literature of the outcome studies reported in patients following traumatic upper-extremity (UE) nerve injuries (excluding amputation), to assess the presence of an association between neuropathic pain and outcome in patients following traumatic UE nerve injuries, and to provide recommendations for inclusion of more comprehensive outcome measures by clinicians who treat these patients.

SUMMARY OF KEY POINTS

A Medline and CINAHL literature search retrieved 48 articles. This review identified very few studies of patients with peripheral nerve injury that reported neuropathic pain. When pain was reported, visual analogue or numeric rating scales were most frequently used; standardized questionnaires measuring pain or psychosocial function were rarely administered. Recent evidence shows substantial long-term disability and pain in patients following peripheral nerve injury.

RECOMMENDATION

To better understand neuropathic pain in patients following peripheral nerve injury, future outcome studies should include valid, reliable measures of physical impairment, pain, disability, health-related quality of life, and psychosocial functioning.

Self-report of depressive symptoms in African American and white women in primary care

OBJECTIVES

Depressive symptoms are frequently seen among female patients in primary care. The majority of screening instruments are cumbersome for a busy clinic.

METHOD

The effectiveness of a 2-item depression screening questionnaire was compared to the mental health section of the 36-Item Short Form Health Survey (SF-36). A total of 127 consecutive patients who presented for primary care service agreed to participate and completed the questionnaire.

RESULTS

Of the final sample, 65.4% were African American and 44.9% of all women reported having depressive symptoms, with no significant difference in the prevalence of reported depressive symptoms between African American and white women (chi2 = 1.97, p = .16). The women reporting depressive symptoms were more likely to be in the lower-income group (chi2 = 9.02, p = .01); however, in stratified analysis this was only significant for the African American women (chi2 = 8.69, p = .01). Analysis of variance demonstrated that the women with depressive symptoms were more likely to score low on the mental health subscales of the SF-36 when adjusted for income (F = 58.32, P < .0001). Within race groups, the mean Mental Health Index scores were higher among African American women (t = -6.45, P <.0001) and White women (t = -3.59, P = .002) who reported depressive symptoms than among those who did not report depressive symptoms. The sensitivity and specificity of the 2-item depression symptom questions compared to the overall SF-36 mental health score were 70% and 77%, respectively.

CONCLUSION

A simple 2-item questionnaire can be used to identify depressive symptoms in white and African American women in a primary care clinic.

An open-label, non-randomized comparison of venlafaxine and gabapentin as monotherapy or adjuvant therapy in the management of neuropathic pain in patients with peripheral neuropathy

Although many therapies are used in the management of neuropathic pain (NeP) due to polyneuropathy (PN), few comparison studies exist. We performed a prospective, non-randomized, unblended, efficacy comparison of the serotonin-norepinephrine reuptake inhibitor venlafaxine, as either monotherapy or adjuvant therapy, with a first-line medication for NeP, gabapentin, in patients with PN-related NeP. VAS pain scores were assessed after 3 and 6 months in intervention groups and in a cohort of patients receiving no pharmacotherapy. In a total of 223 patients, we analyzed pain quantity and quality (visual analogue scale [VAS] score, Brief Pain Inventory [BPI]), quality of life and health status measures [EuroQol 5 Domains, EQ-5D], Medical Outcomes Sleep Study Scale [MOSSS], Hospital Anxiety and Depression Scale [HADS] and Short Form 36 Health Survey [SF-36]) after 6 months of therapy. Significant improvements in VAS pain scores occurred for all treatment groups after 6 months. Improvements in aspects of daily life and anxiety were identified in all treatment groups. Our data suggest that monotherapy or adjuvant therapy with venlafaxine is comparable to gabapentin for NeP management. We advocate for head-to-head, randomized, double-blinded studies of current NeP therapies.

The burden of neuropathic pain: a systematic review and meta-analysis of health utilities

Patients with neuropathic pain (NeuP) experience substantially lower health-related quality of life (HRQoL) than the general population. The aim of this systematic review and meta-analysis is to test the hypothesis that NeuP is associated with low levels of health utility. A structured search of electronic databases (MEDLINE, EMBASE, Cochrane Library and CINAHL) was undertaken. Reference lists of retrieved reports were also reviewed. Studies reporting utility single-index measures (preference based) in NeuP were included. Random effects meta-analysis was used to pool EQ-5D index utility estimates across NeuP conditions. The association of utilities and pre-defined factors (NeuP condition, patient age, sex, duration and severity of pain and method of utility scoring) was examined using meta-regression. Twenty-four studies reporting health utility values in patients with NeuP were included in the review. Weighted pooled utility score across the studies varied from a mean of 0.15 for failed back surgery syndrome to 0.61 for post-herpetic neuralgia and diabetic neuropathy. Although there was substantial heterogeneity (P<0.0001) across studies, we found little variation in utility as a function of patient and study characteristics. The single exception was a significant relationship (P<0.0001) between increasing neuropathic pain severity and a reduction in utility. This study confirms the hypothesis that patients with NeuP experience low utilities and therefore low HRQoL. However, the contribution of non-NeuP co-morbidity remains unclear. Neuropathic pain severity emerged as a primary predictor of the negative health impact of NeuP.

Anatomically specific patterns of glial activation in the periaqueductal gray of the sub-population of rats showing pain and disability following chronic constriction injury of the sciatic nerve

Neuropathic pain conditions for which treatment is sought are characterized by complex behavioural disturbances, as well as "pain." Recent studies using chronic constriction injury of the sciatic nerve have shown that rats develop three distinct patterns of disability characterized by changes in social-interactions and sleep-wake cycle behaviours post-injury: (i) Persistent Disability, (ii) Transient Disability and (iii) No Disability. These patterns occur despite all rats showing identical levels of allodynia and hyperalgesia (i.e., pain). In rats, social-interactions and sleep-wake cycle behaviours are regulated in part, by neural networks, which converge on the periaqueductal grey (PAG). We sought therefore to identify neural adaptations in the PAG, 6 days following chronic constriction injury (CCI), the time at which rats in which disabilities persist are first distinguished from those without disabilities (i.e., No Disability and Transient Disability). GeneChips, RT-PCR and Western blotting revealed the select up-regulation in translation and transcription of glial fibrillary acidic protein (GFAP) and Vimentin in rats with Persistent Disability. Significant increases in GFAP immunoreactivity were localized histologically to the lateral and caudal ventrolateral columns of the PAG. This anatomically specific pattern of increased GFAP suggests activation of astrocytes by select neural pathways, which likely include afferents of both spinal and nucleus of the solitary tract (NTS) origin. The PAG columns in which astrocytes are activated play significant roles in modulating both social-interactions and the sleep-wake cycle. It is possible therefore that the persistent disabilities seen in a subgroup of CCI rats are in part a functional consequence of this specific pattern of astrocyte activation.

Relationship between health-related quality of life, pain, and functional disability in neuropathic pain patients with failed back surgery syndrome

OBJECTIVES

Patients with failed back surgery syndrome (FBSS) and chronic neuropathic pain experience levels of health-related quality of life (HRQoL) that are considerably lower than those reported in other areas of chronic pain. The aim of this article was to quantify the extent to which reductions in (leg and back) pain and disability over time translate into improvements in generic HRQoL as measured by the EuroQoL-5D and SF-36 instruments.

METHODS

Using data from the multinational Prospective, Randomized, Controlled, Multicenter Study of Patients with Failed Back Surgery Syndrome trial, we explore the relationship between generic HRQoL--assessed using two instruments often used in clinical trials (i.e., the SF-36 and EuroQol-5D)--and disease-specific outcome measures (i.e., Oswestry disability index [ODI], leg and back pain visual analog scale [VAS]) in neuropathic patients with FBSS.

RESULTS

In our sample of 100 FBSS patients, generic HRQoL was moderately associated with ODI (correlation coefficient: -0.462 to -0.638) and mildly associated with leg pain VAS (correlation coefficient: -0.165 to -0.436). The multilevel regression analysis results indicate that functional ability (as measured by the ODI) is significantly associated with HRQoL, regardless of the generic HRQoL instrument used. On the other hand, changes over time in leg pain were significantly associated with changes in the EuroQoL-5D and physical component summary scores, but not with the mental component summary score.

CONCLUSIONS

Reduction in leg pain and functional disability is statistically significantly associated with improvements in generic HRQoL. This is the first study to investigate the longitudinal relationship between generic and disease-specific HRQoL of neuropathic pain patients with FBSS, using multinational data.

Spinal cord stimulation as a novel approach to the treatment of refractory neuropathic mediastinal pain

Spinal cord stimulation (SCS) offers new hope for patients with neuropathic pain. SCS "neuromodulates" the transmission and response to "painful" stimuli. The efficacy of SCS has been established in the treatment of a variety of neuropathic pain conditions and more recently in refractory angina pectoris, peripheral vascular disease, and failed back surgery syndrome. Recent publications suggest that visceral pain could be successfully treated with SCS. We report the first successful use of a spinal cord stimulator in the treatment of refractory neuropathic mediastinal, esophageal, and anterior neck pain following esophagogastrectomy.

The effects of spinal cord stimulation in neuropathic pain are sustained: a 24-month follow-up of the prospective randomized controlled multicenter trial of the effectiveness of spinal cord stimulation

OBJECTIVE

After randomizing 100 failed back surgery syndrome patients to receive spinal cord stimulation (SCS) plus conventional medical management (CMM) or CMM alone, the results of the 6-month Prospective Randomized Controlled Multicenter Trial of the Effectiveness of Spinal Cord Stimulation (i.e., PROCESS) showed that SCS offered superior pain relief, health-related quality of life, and functional capacity. Because the rate of crossover favoring SCS beyond 6 months would bias a long-term randomized group comparison, we present all outcomes in patients who continued SCS from randomization to 24 months and, for illustrative purposes, the primary outcome (>50% leg pain relief) per randomization and final treatment.

METHODS

Patients provided data on pain, quality of life, function, pain medication use, treatment satisfaction, and employment status. Investigators documented adverse events. Data analysis included inferential comparisons and multivariate regression analyses.

RESULTS

The 42 patients continuing SCS (of 52 randomized to SCS) reported significantly improved leg pain relief (P < 0.0001), quality of life (P <or= 0.01), and functional capacity (P = 0.0002); and 13 patients (31%) required a device-related surgical revision. At 24 months, of 46 of 52 patients randomized to SCS and 41 of 48 randomized to CMM who were available, the primary outcome was achieved by 17 (37%) randomized to SCS versus 1 (2%) to CMM (P = 0.003) and by 34 (47%) of 72 patients who received SCS as final treatment versus 1 (7%) of 15 for CMM (P = 0.02).

CONCLUSION

At 24 months of SCS treatment, selected failed back surgery syndrome patients reported sustained pain relief, clinically important improvements in functional capacity and health-related quality of life, and satisfaction with treatment.

The epidemiological, clinical, and pathological rationale for the herpes zoster vaccine

Worldwide, herpes zoster (HZ) affects millions of patients (particularly older adults) annually and causes significant suffering due to acute and chronic pain, or postherpetic neuralgia (PHN). The objective of this article is to explain the rationale for the HZ vaccine by summarizing data on the epidemiology of HZ in the immunocompetent host, with a focus on recent incidence and risk factor studies; to review information on the burden of HZ; and to discuss the challenges of lessening the morbidity of the disease. The incidence and severity of HZ and PHN are highest in older adults. Given the central nervous system damage caused by HZ, the difficulty of adequately treating HZ to prevent PHN, and the intractability of PHN, the advent of the HZ vaccine appears to be a crucial innovation for preventing HZ and PHN.

The health consequences of peripheral neurological deficits in an elderly cohort: an Oklahoma Physicians Resource/Research Network Study

OBJECTIVES

To determine whether the belief that loss of deep tendon reflexes and vibratory sensation in the ankles in older patients is of no great consequence is valid.

DESIGN

Four-year longitudinal cohort study.

SETTING

Primary care practice-based research network.

PARTICIPANTS

Six hundred four noninstitutionalized individuals aged 65 and older with no self-reported medical conditions known to cause peripheral neuropathy (PN), recruited from the practices of 23 primary care physicians in central Oklahoma.

MEASUREMENTS

Annual standardized peripheral neurological examination performed by two research nurses plus a questionnaire that included self-reported measures of health, health-related quality of life (HRQoL Quality of Well-Being--Self Administered (QWB-SA) and Health Utilities Index-3 (HUI-3), physical functioning--(Medical Outcomes Study 36-item Short Form Survey (SF-36)), falls, and use of healthcare services. Deaths were determined from participant contacts, primary care physicians, and the Social Security death index.

RESULTS

One hundred sixty of 604 participants had symmetrical peripheral neurological deficits (SPNDs). After controlling for age, sex, race, education, income, body mass index, HRQoL, physical functioning, self-rated health, cognitive test score, and a variety of medical conditions, SPNDs were associated with earlier hospitalization (P=.03); greater mortality (P<.001); and declines in HRQoL (QWB-SA, P<.001), self-rated health (P=.02) physical functioning (SF-36, P=.005), and bodily pain (SF-36, P=.001).

CONCLUSION

SPNDs of undetermined cause, found in older patients on physical examination, appear to be associated with greater morbidity and mortality.