Neuropathic Pain Symptom Inventory Scores Research Articles

Analysis of the efficacy and safety of pulsed radiofrequency for the treatment of thoracic postherpetic neuralgia in elderly patients with different pain phenotypes

Objective: To analyze the efficacy and safety of pulsed radiofrequency (PRF) for the treatment of thoracic postherpetic neuralgia (PHN) in elderly patients with different pain phenotypes. Methods: A total of 201 elderly thoracic PHN patients, including 110 males and 91 females aged (72.2±6.9) years who received high-voltage, long-duration PRF at the dorsal root ganglion at Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese Medicine from January 2020 to December 2022, were retrospectively included. The neuropathic pain symptom inventory (NPSI) was used to evaluate the five different pain phenotypes, which included superficial spontaneous pain, deep spontaneous pain, paroxysmal pain, evoked pain, and paresthesia/dysesthesia, and to analyze the distribution of the five pain phenotypes. The numerical rating scale (NRS) and NPSI scores of all patients were compared before treatment and three months after treatment to evaluate the efficacy and safety of PRF for different pain phenotypes and pain phenotype combinations. Results: All patients had two or more pain phenotypes, and 50.2% (101/201) of the patients had five pain phenotypes at the same time. Compared with those before treatment, three months after treatment, the NPSI scores for superficial spontaneous pain, deep spontaneous pain, paroxysmal pain, evoked pain and paresthesia/dysesthesia decreased (all P<0.05), and the scores decreased by［M（Q1，Q3）］3.0 (2.0, 4.0), 1.5 (0.5, 2.5), 3.0 (2.5, 4.0), 2.3 (1.0, 4.0), and 1.0 (0.5, 2.0) points, respectively, the differences were statistically significant (P<0.001). The decrease in the NPSI score in patients with paroxysmal pain was greater than that in patients with the other 4 pain phenotypes (all P<0.05). After treatment, the NRS score decreased by 4.0 (3.0, 5.0), 4.0 (3.0, 5.0), 4.0 (3.0, 5.0) and 5.0 (4.0, 6.0) points in patients with 2, 3, 4 and 5 pain phenotypes, respectively, and the difference was statistically significant (P<0.001). The decrease in the NRS score was greater in patients with a combination of 5 pain phenotypes than that in patients with a combination of 3 and 4 pain phenotypes (all P<0.05). No complications, such as pneumothorax, haematoma or infection, occurred in any of the patients during treatment. Conclusion: PRF has different therapeutic effects on PHN patients with different pain phenotypes, it has the best effect on paroxysmal pain, and the treatment is safe.

Paradoxical heat sensation as a manifestation of thermal hypesthesia: a study of 1090 patients with lesions of the somatosensory system.

Paradoxical heat sensation (PHS) is the perception of warmth when the skin is cooled. Paradoxical heat sensation rarely occurs in healthy individuals but more frequently in patients suffering from lesions or disease of the peripheral or central nervous system. To further understand mechanisms and epidemiology of PHS, we evaluated the occurrence of PHS in relation to disease aetiology, pain levels, quantitative sensory testing parameters, and Neuropathic Pain Symptom Inventory (NPSI) items in patients with nervous system lesions. Data of 1090 patients, including NPSI scores from 404 patients, were included in the analysis. We tested 11 quantitative sensory testing parameters for thermal and mechanical detection and pain thresholds, and 10 NPSI items in a multivariate generalised linear model with PHS, aetiology, and pain (yes or no) as fixed effects. In total, 30% of the neuropathic patients reported PHS in contrast to 2% of healthy individuals. The frequency of PHS was not linked to the presence or intensity of pain. Paradoxical heat sensation was more frequent in patients living with polyneuropathy compared with central or unilateral peripheral nerve lesions. Patients who reported PHS demonstrated significantly lower sensitivity to thermal perception, with lower sensitivity to normally painful heat and cold stimuli. Neuropathic Pain Symptom Inventory scores were lower for burning and electric shock-like pain quality for patients with PHS. Our findings suggest that PHS is associated with loss of small thermosensory fibre function normally involved in cold and warm perception. Clinically, presence of PHS could help screening for loss of small fibre function as it is straightforward to measure or self-reported by patients.

Cutaneous nerve fiber and peripheral Nav1.7 assessment in a large cohort of patients with postherpetic neuralgia.

The mechanisms of pain in postherpetic neuralgia (PHN) are still unclear, with some studies showing loss of cutaneous sensory nerve fibers that seemed to correlate with pain level. We report results of skin biopsies and correlations with baseline pain scores, mechanical hyperalgesia, and the Neuropathic Pain Symptom Inventory (NPSI) in 294 patients who participated in a clinical trial of TV-45070, a topical semiselective sodium 1.7 channel (Nav1.7) blocker. Intraepidermal nerve fibers and subepidermal Nav1.7 immunolabeled fibers were quantified in skin punch biopsies from the area of maximal PHN pain, as well as from the contralateral, homologous (mirror image) region. Across the entire study population, a 20% reduction in nerve fibers on the PHN-affected side compared with that in the contralateral side was noted; however, the reduction was much higher in older individuals, approaching 40% in those aged 70 years or older. There was a decrease in contralateral fiber counts as well, also noted in prior biopsy studies, the mechanism of which is not fully clear. Nav1.7-positive immunolabeling was present in approximately one-third of subepidermal nerve fibers and did not differ on the PHN-affected vs contralateral sides. Using cluster analysis, 2 groups could be identified, with the first cluster showing higher baseline pain, higher NPSI scores for squeezing and cold-induced pain, higher nerve fiber density, and higher Nav1.7 expression. While Nav1.7 varies from patient to patient, it does not seem to be a key pathophysiological driver of PHN pain. Individual differences in Nav1.7 expression, however, may determine the intensity and sensory aspects of pain.

Evaluating the efficacy of combination therapy of Pregabalin plus Nortriptyline in the management of PHN patients: A randomized controlled study

Background: Post Herpetic Neuralgia (PHN) is chronic neuropathic pain. It is a complication of herpes zoster and negatively impacts the patient’s quality of life and physical, occupational, social and psychosocial abilities due to unceasing pain. As pain management remains the cornerstone in treating such patients, this study was undertaken to determine the efficacy of fixed-dose combination therapy of Pregabalin plus Nortriptyline in PHN. Methods: The study, which was a follow-up, randomised, single-blind, controlled study, included a total of 40 patients who had chronic pain for at least 12 weeks with a Numeric rating scale (NRS) score of 5/10 or above. Group A (n=20) received pregabalin 75 mg plus nortriptyline 10 mg, and group B (n=20) received pregabalin 75 mg for a total of 12 weeks. Pain intensity and severity (using NRS and Global Perceived Effect), pain interference with sleep (using Numeric Rating Scale-Sleep (NRS-Sleep) and Pain Detect Questionnaire (PDQ)), pain quality (using Neuropathic Pain Symptom Inventory (NPSI)), and quality of life (QoL) (using Short Form-12 (SF-12) questionnaire) at the end of the first, second, fourth, eighth and twelfth week were measured. Results: Significant (p &lt;0.05) decline in Numeric rating scale (NRS) scores, NRS sleep and NPSI scores in group A along with significant (p &lt;0.05) improvement in PDQ, GPE and QoL scores, when compared to group B. Conclusion: The combination of pregabalin plus nortriptyline therapy has better patient outcomes in PHN as compared to pregabalin monotherapy.

Characteristics of Diverse Verbal Pain Descriptors in South Korean Patients With Peripheral Neuropathic Pain: 'Jeorim' (Tingling) and 'Sirim' (Cold) as Key Neuropathic Pain Descriptors.

The description of pain is the most-important indicator leading to the adequate treatment of patients with neuropathic pain (NeP). The purpose of this study was to identify and characterize the unique features of Korean verbal descriptions in patients with peripheral NeP. This study included 400 patients (167 males and 233 females) and their 1,387 pain-description responses. Patients with peripheral NeP freely described their symptoms in Korean. Collected verbal descriptions were grouped according to terminologies with similar meanings. Participants completed validated patient-reported outcome scales including the neuropathic pain symptom inventory (NPSI) and painDETECT questionnaire (PD-Q). The frequencies of each verbal pain descriptor were compared between the NPSI and PD-Q scores. 'Jeorim' (tingling) was the most common among 17 types of organized verbal pain descriptors, and the 'Sirim' (cold) symptom had a significantly higher rate of use in the 2 high-severity groups when participants were classified by their total scores on the NPSI and PD-Q. Korean verbal NeP descriptors were significantly diverse. The Jeorim (tingling) and Sirim (cold) descriptors can be utilized in evaluations of Korean patients with NeP.

A Comparison of Self-reported Pain Measures Between Sensory Phenotypes in HIV-associated Sensory Neuropathy

Painful HIV-associated neuropathy (HIV-SN) is a prevalent co-morbidity of HIV infection. Sensory phenotyping, using quantitative sensory testing (QST) could allow for improved stratification to guide personalized treatment. However, previous methods of QST interpretation have demonstrated limited association with self-reported pain measures. This study sought to identify differences in self-reported pain measures between composite QST-derived sensory phenotypes, and to examine any differences in participants reporting multi-site, multi-etiology chronic pain. In this cross-sectional observational study of participants with HIV (n = 133), individuals were allocated to neuropathy and neuropathic pain groups through clinical assessment and nerve conduction testing. They completed symptom-based questionnaires and underwent standardized QST. Participants were assigned, by pre-determined algorithm, to a QST-derived sensory phenotype. Symptoms were compared between sensory phenotypes. Symptom characteristics and Neuropathic Pain Symptom Inventory scores differed between QST-derived sensory phenotypes: ‘sensory loss’ was associated with more paroxysmal and paraesthetic symptoms compared to ‘thermal hyperalgesia’ and ‘healthy’ phenotypes (P = .023–0.001). Those with painful HIV-SN and additional chronic pain diagnoses were more frequently allocated to the ‘mechanical hyperalgesia’ phenotype compared to those with painful HIV-SN alone (P = .006). This study describes heterogeneous sensory phenotypes in people living with HIV. Differences in self-reported pain outcomes between sensory phenotypes has the potential to guide future stratified trials and eventually more targeted therapy. PerspectiveThis article presents quantitative sensory testing derived phenotypes, thought to reflect differing pathophysiological pain mechanisms and relates them to self-reported pain measures in people with HIV infection. This could help clinicians stratify patients to individualize analgesic interventions more effectively.

Abstract No. : ABS2276: Modulation of mRNA expression of mTORC1 and IL-6 and comparison of the efficacy and safety of transdermal fentanyl versus transdermal buprenorphine for prevention of chronic persistent post surgical pain in head and neck cancer patients: A randomised, pilot study

Background and Aims:This study compared the efficacy and safety of transdermal buprenorphine (TDB) and transdermal fentanyl (TDF) in prevention of chronic persistent post-surgical pain (CPPP) and modulation of mRNA expression of interlukin (IL-6) and mTORC1 genes in patients of head and neck carcinoma (HNC).Methods:Patients aged >18 years who were operated for HNC with numerical rating scale(NRS)pain scores≥4/10 on post-operative day-6 were enroled. A baseline assessment was done and written informed consent was obtained. The pain intensity and severity were evaluated byNRS-pain, PDQ scores (pain detect questionnaire), and neuropathic pain symptom inventory (NPSI) scores and quality of life was evaluated by utilizing Short Form-12 (SF-12). Gene expression analysis was carried out at baseline and after treatment completion. On post-operative day 6, patients of group F (n=20) received TDF (50 µg/hour) and group B (n=20) received TDB (10 µg/hour).Results:the A total of 40 patients with 20 in each group were included in this study. Following 12 weeks of treatment, gene studiesdemonstrated downregulation of the mRNA expression of IL-6 and mTORC1, which was statistically significant in both groups. A statistically significant decline in NRS-Pain, PDQ scores and NPSI scores and a statistically significant improvement in the physical and mental component scores of SF-12 was also observed in both groups (table 1).NRS Pain ScoreGroup-B Mean±SDIntra group comparison with Baseline line (P)Group-F Mean±SDIntra group comparison with Baseline line (P)Inter group comparison PBaseline7.45±1.23____7.5±7.48____1.00End of week 16.1±1.25<0.0015.15±5.63<0.0010.108End of week 25.05±1.15<0.0014.25±4.65<0.0010.252End of week 43.2±1.11<0.0013.4±3.3<0.0011.00End of week 81.8±1.11<0.0012.5±2.15<0.0010.402End of week 120.6±0.68<0.0011.29±0.93<0.0010.049SD- standard deviation, NRS -numerical rating scaleConclusion:Significant downregulation in mRNA expression of IL-6 and mTORC1 was observed after both transdermal fentanyl and transdermal buprenorphine and both were equally efficacious for prevention of CPPP and improving quality of life following HNC surgery.

Clinical Outcomes after Spinal Cord Stimulation According to Pain Characteristics.

ObjectiveSpinal cord stimulation (SCS) is an effective treatment for chronic neuropathic pain. However, its clinical efficacy in regard to specific types of pain has not been well studied. The primary objective of this study was to retrospectively analyze the clinical outcomes of paddle-type SCS according to the type of neuropathic pain. MethodsSeventeen patients who underwent paddle-lead SCS at our hospital were examined. Clinical outcomes were evaluated pre- and postoperatively (3 months, 1 year, and last follow-up) using the Neuropathic Pain Symptom Inventory (NPSI). The NPSI categorizes pain as superficial, deep, paroxysmal, evoked, or dysesthesia and assess the duration of the pain (pain time score). Changes in NPSI scores were compared with change in Visual analogue scale (VAS) scores. ResultsAfter SCS, the pain time score improved by 45% (independent t-test, p=0.0002) and the deep pain score improved by 58% (independent t-test, p=0.001). Improvements in the pain time score significantly correlated with improvements in the VAS score (r=0.667, p=0.003, Spearman correlation). Additionally, the morphine milligram equivalent value was markedly lower after vs. before surgery (~49 mg, pared t-test, p=0.002). No preoperative value was associated with clinical outcome. ConclusionThe NPSI is a useful tool for evaluating the therapeutic effects of SCS. Chronic use of a paddle-type spinal cord stimulation improved the deep pain and the pain time scores.

Effects of Transcutaneous Spinal Direct Current Stimulation (tsDCS) in Patients With Chronic Pain: A Clinical and Neurophysiological Study.

Background and Aims: Chronic pain is a complex clinical condition, often devastating for patients and unmanageable with pharmacological treatments. Converging evidence suggests that transcutaneous spinal Direct Current Stimulation (tsDCS) might represent a complementary therapy in managing chronic pain. In this randomized, double-blind and sham-controlled crossover study, we assessed tsDCS effects in chronic pain patients.Methods: Sixteen patients (aged 65.06 ± 16.16 years, eight women) with chronic pain of different etiology underwent sham and anodal tsDCS (anode over the tenth thoracic vertebra, cathode over the somatosensory cortical area: 2.5 mA, 20 min, 5 days for 1 week). As outcomes, we considered the Visual Analog Scale (VAS), the Neuropathic Pain Symptom Inventory (NPSI), and the components of the lower limb flexion reflex (LLFR), i.e., RIII threshold, RII latency and area, RIII latency and area, and flexion reflex (FR) total area. Assessments were conducted before (T0), immediately at the end of the treatment (T1), after 1 week (T2) and 1 month (T3).Results: Compared to sham, anodal tsDCS reduced RIII area at T2 (p = 0.0043) and T3 (p = 0.0012); similarly, FR total area was reduced at T3 (p = 0.03). Clinically, anodal tsDCS dampened VAS at T3 (p = 0.015), and NPSI scores at T1 (p = 0.0012), and T3 (p = 0.0015), whereas sham condition left them unchanged. Changes in VAS and NPSI scores linearly correlated with the reduction in LLFR areas (p = 0.0004).Conclusions: Our findings suggest that tsDCS could modulate nociceptive processing and pain perception in chronic pain syndromes.

Stratification of patients based on the Neuropathic Pain Symptom Inventory: development and validation of a new algorithm.

The personalization of neuropathic pain treatment could be improved by identifying specific sensory phenotypes (ie, specific combinations of symptoms and signs) predictive of the response to different classes of drugs. A simple and reliable phenotyping method is required for such a strategy. We investigated the utility of an algorithm for stratifying patients into clusters corresponding to specific combinations of neuropathic symptoms assessed with the Neuropathic Pain Symptom Inventory (NPSI). Consistent with previous results, we first confirmed, in a cohort of 628 patients, the existence of a structure consisting of 3 clusters of patients characterized by higher NPSI scores for: pinpointed pain (cluster 1), evoked pain (cluster 2), or deep pain (cluster 3). From these analyses, we derived a specific algorithm for assigning each patient to one of these 3 clusters. We then assessed the clinical relevance of this algorithm for predicting treatment response, through post hoc analyses of 2 previous controlled trials of the effects of subcutaneous injections of botulinum toxin A. Each of the 97 patients with neuropathic pain included in these studies was individually allocated to one cluster, by applying the algorithm to their baseline NPSI responses. We found significant effects of botulinum toxin A relative to placebo in clusters 2 and 3, but not in cluster 1, suggesting that this approach was, indeed, relevant. Finally, we developed and performed a preliminary validation of a web-based version of the NPSI and algorithm for the stratification of patients in both research and daily practice.

Incidence of contralateral neurosensitive changes and persistent postoperative pain 6 months after mastectomy: A prospective, observational investigation.

Mirror image sensory dysfunction (MISD) after breast surgery has not yet been studied. This prospective observational study aimed to determine the incidence of MISD, persistent postoperative pain (PPP) and mirror image pain (MIP) during 6 months after total unilateral mastectomy.Visual analogue scale (VAS), Neuropathic Pain Symptom Inventory (NPSI), Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS), Life orientation test (LOT) and Quantitative Sensory Testing (QST) (in ipsi and contralateral breast, axilla and thigh) were recorded. VAS > 3 at 1, 3, and 6 postoperative months was considered PPP. Contralateral changes of QST at any time was considered indicative of MISD and spontaneous contralateral VAS ≥ 1 as MIP.Sixty-four patients were included. PPP at 1, 3 and 6 months was 18.8%, 56.2%, and 21.3%, respectively Ten patients presented MIP. MISD was detected in 79.7% patients in contralateral breast and 62.5% in contralateral axilla. Furthermore, changes in QST were present in 39.1% of patients in thigh. Electronic Von Frey (EVF) changes in both contralateral breast and axilla, and in thigh significantly diminished at all postoperative times. Changes of postoperative EVF ≥ 20% in contralateral breast were associated to higher VAS values. NPSI scores were significantly higher at all postoperative times. At 1 month, PCS, depression HADS subscale and LOT scores were significantly worse than all the other periods.MISD incidence was almost 80%, and 15.6% of patients showed spontaneous contralateral VAS ≥ 1. At 6 months 21.3% of patients manifested PPP. The worst alteration of factors related to PPP occurred at 1 postoperative month. Most consistent QST was EVF.

248 Sensitive Skin can be Small Fiber Neuropathy: Results from a Case-control Quantitative Sensory Testing Study

Sensitive skin syndrome (SSS) is defined as the occurrence of unpleasant sensations (itch, pain, burnings, prickling…) in response to stimuli that should not normally cause such sensations. Previous studies show that SSS could be a small-fiber neuropathy but quantitative sensory testing (QST) is lacking. Using QST, the aim of the study was to determine the presence or absence of tactile sensitivity disorder, mainly heat-pain threshold (HPT 0.5), in subjects with SSS. Neuropathic pain was assessed by two questionnaires: the DN4 and the Neuropathic Pain Symptom Inventory (NPSI). This monocentric case-control study included 21 subjects with SSS and 21 controls. The subjects underwent quantitative sensory testing. Neuropathic pain was assessed by two questionnaires: the DN4 and the Neuropathic Pain Symptom Inventory (NPSI). Forty-two subjects were included in the study. The HPT 0.5 was significantly lower in the cases (14.5+/-2.8) than in the controls (17.8+/-2.5) (p<0.001). Intermediate pain (HPT 5.0) was also significantly decreased in SSS. The DN4 and NPSI scores were significantly higher in the cases compared to the controls. The decrease in HPT in subjects with SSS compared to controls suggests the presence of hyperalgesia, probably due to the damage of C-fibers. These findings, as well as the increased DN4 and NPSI scores, strengthen the neuronal hypothesis of SSS and are new arguments for consideration of SSS as small fiber neuropathy.

A clinical study on the pain following brachial plexus injury and its correlative factors

Objective To evaluate the characteristic and correlative factors of pain following traumatic brachial plexus injury and the impact of surgery on pain. Methods This study was a prospective, self-controlled study. Each enrolled patient was asked to respond to the revised short form McGill pain (SF-MPQ-2) and neuropathic pain symptom inventory (NPSI) questionnaire before and after surgery. Multiple factors analysis on pain was carried out and the effect of surgery on pain was evaluated. Results The total number of the study was 100 patients. Both of the SF-MPQ-2 38.33±30.38 and NPSI 15.62±14.84 scores after surgery were significantly lower than those before surgery SF-MPQ-2 50.13±36.55; NPSI 20.24±16.84. The highest score appeared in affective descriptors of the four subscales in SF-MPQ-2 and the score of paresthesia was the highest in the 5 divisions of NPSI, no matter before or after surgery. The postoperative scores of deep pain, evoked pain and paresthesia were significantly lower than the preoperative scores. Preoperative pain was related to whether nerve continuity existed or not (SF-MPQ-2: r=-0.2198, P=0.0280; NPSI: r=-0.2322, P=0.0201). The postoperative SF-MPQ-2 and NPSI scores were significantly lower than preoperative scores in motorcycle accident and weight dropping groups. The SF-MPQ-2 and NPSI scores were the highest in global brachial plexus injury group before and after operation. The SF-MPQ-2 and NPSI scores in global brachial plexus injury group or upper and middle trunks injury group after surgery were significantly lower than those before surgery. The postoperative SF-MPQ-2 and NPSI scores in nerve transfer or neurolysis group were significantly lower than preoperative scores. Conclusion In the study, according to SF-MPQ-2 and NPSI evaluation, affective descriptors and paresthesia accounted for the largest proportion in pain expression. Nerve transfer or neurolysis might have a positive effect on prognosis of neuropathic pain for traumatic brachial plexus injury. Surgery might relieve deep pain and evoked pain and paresthesia. Key words: Brachial plexus; Prospective studies; Neuropathic pain; SF-MPQ-2; NPSI

Efficacy, Safety and Cost Effectiveness of Amitriptyline and Pregabalin in Patients with Diabetic Peripheral Neuropathy

The tricyclic antidepressant, amitriptyline and the anticonvulsant, pregabalin are the most frequently used medications in general practice for diabetic peripheral neuropathy. This study compares the effectiveness of amitriptyline vs. pregabalin using neuropathic pain symptom inventory and visual analogue scale, the incidence of adverse drug reactions and the cost effectiveness. Effectiveness was measured using visual analogue scale and neuropathic pain symptom inventory scores both before and after therapy. Adverse drug reactions were documented after the therapy and cost effectiveness was measured using incremental cost effectiveness analysis ratio. Both drugs showed obvious pain relief. Visual analogue scale mean difference scores showed statistically significant difference in efficacy for amitriptyline and pregabalin. Incidences of adverse drug reactions were more or less similar in terms of magnitude. Furthermore the cost of amitriptyline is less than that of pregabalin. Hence we concluded that amitriptyline was a better choice of therapy than pregablin because it was well tolerated and has a lower cost for the additional effectiveness achieved.

A Survey of Chronic Pain Due to Spinal Dural Arteriovenous Fistulae.

Chronic pain due to spinal dural arteriovenous fistulae (SDAVF) during follow-up is a serious issue because it can affect patients' quality of life. The severity of posttreatment chronic leg pain in patients with SDAVF is unclear. To investigate the prevalence, severity, and characteristics of chronic leg pain in patients with SDAVF and to examine the clinical factors associated with chronic pain. We conducted a survey of their chronic posttreatment leg pain in 49 SDAVF patients. It consisted of a numeric rating scale and a neuropathic pain symptom inventory (NPSI). Of the 49 patients, 32 (65.3%) completed the questionnaire. There were 24 males and 8 females whose mean age was 69.1 years. The mean follow-up period was 86.3 months. Chronic leg pain was reported by 26 (81.3%) of 32 patients; 14 experienced pain before treatment and 12 had new-onset posttreatment pain. The pain was reported as moderate to severe by 21 (80.8%) of 26 patients; the mean numeric rating scale and NPSI scores were 6.0 ± 2.3 and 17.4 ± 10.3, respectively. The NPSI subscores were significantly higher for spontaneous pain and paresthesia/dysesthesia than for paroxysmal pain. We found no significant clinical factors related to chronic posttreatment pain; on magnetic resonance imaging scans we identified spinal cord atrophy in 8 patients with chronic pain. Most of our SDAVF patients reported moderate to severe chronic leg pain characterized by spontaneous pain and paresthesia/dysesthesia. Spinal cord atrophy on magnetic resonance imaging scans was a characteristic in patients with chronic pain.

Reduction of Intraepidermal Nerve Fiber Density (IENFD) in the skin biopsies of patients with fibromyalgia: A controlled study

ObjectivesFibromyalgia (FM) is one of the most common chronic pain syndromes. Various pathogenetic mechanisms have been implicated but none is proven. Our scope was to determine if Intraepidermal Nerve Fiber Density (IENFD) is reduced in the skin of FM patients, as observed in patients with painful small fiber sensory neuropathy (SFSN). Design, setting and participantsWe prospectively studied 46 FM patients (5 men and 41 women), aged 29 to 76 (mean: 52.5) years, diagnosed according to the ACR 2010 criteria, and 34 controls (18 women and 16 men) aged 19 to 84 (mean: 31.7) years. IENFD was measured using published guidelines and immune markers were sought immunocytochemically. In 30 FM patients, pain intensity was assessed with the Neuropathic Pain Symptom Inventory (NPSI), a scale validated for neuropathic pain. Results15 of 46 (32.6%) FM patients had reduced IENFD [range: 0.6–12.5fibers/mm (mean: 4.83 SD: 2.5)], compared to healthy controls [2.8–11.5fibers/mm (mean: 7.35, SD: 1.85)] (p<0.0001). No significant correlation was noticed between NPSI scores and IENFD. No difference in the Langerhans cells, the major Antigen Presenting Cells (APCs) in the epidermis, or in IL-6 staining, was noted between FM and controls. IENFD was equally reduced in a subset of FM patients who also had another autoimmune disease. ConclusionThis is one of the largest series of FM patients demonstrating a significant reduction of IENFD in their skin biopsies. The findings indicate that in a subset of FM patients, the pain syndrome is, at least partially, of neuropathic origin. Skin biopsy may prove a useful tool and a potential biomarker in future studies of FM patients.

Short-term efficacy of ultramicronized palmitoylethanolamide in peripheral neuropathic pain.

Introduction. This study evaluates the efficacy of palmitoylethanolamide ultramicronized (PEA-um) as an add-on treatment in patients with diabetic or traumatic neuropathic pain (NP). Methods. 30 patients with chronic NP were assessed with Visual Analogue Scale (VAS), NP Symptom Inventory (NPSI), and Health Questionnaire Five Dimensions (EQ-5D), both at baseline and after 10 and 40 days of treatment with 1200 mg/die of PEA-um. All other therapies were maintained stable during the follow-up period. Results. VAS mean score significantly improved within the first 10 days, ranging from 8.20 ± 1.53 to 6.40 ± 1.83 (P < 0.002), with a further decrease to 5.80 ± 2.04 (P < 0.001) after 40 days of PEA-um administration. Moreover, NPSI total score improved from 5.2 ± 1.5 to 3.8 ± 2.1 (P: 0.025) and EQ-5D ranged from −0.30 ± 0.65 to 0.5 ± 0.34 (P < 0.001) between T0 and T2. Conclusions. This study reports the prospective short-term efficacy data of oral PEA-um in patients with diabetic or traumatic NP. A significant improvement was observed both in VAS and NPSI scores and in quality of life scales after 40 days of treatment, although some limitations should be considered, including the short followup and the open-label study design.

A 17-Week, Double-Blind, Placebo-Controlled Trial of Pregabalin for the Treatment of Neuropathic Pain Associated with Spinal Cord Injury: Analysis of Quantitative Assessment of Neuropathic Pain, Modified Brief Pain Inventory Interference Scale and Neuropathic Pain Symptom Inventory Scores

A 17-Week, Double-Blind, Placebo-Controlled Trial of Pregabalin for the Treatment of Neuropathic Pain Associated with Spinal Cord Injury: Analysis of Quantitative Assessment of Neuropathic Pain, Modified Brief Pain Inventory Interference Scale and Neuropathic Pain Symptom Inventory Scores

A Randomized, Prospective Study of Efficacy and Safety of Oral Tramadol in the Management of Post‐Herpetic Neuralgia in Patients from North India

To evaluate the safety and efficacy of oral tramadol therapy (50 to 200 mg/day) in the treatment for post-herpetic neuralgia (PHN). The study was a prospective, single-blind, non-responder vs. responder, randomized trial conducted in 100 outpatients of PHN after oral administration of tramadol for 4 weeks. Those patients who had achieved 50% or greater pain relief after 14 days of oral tramadol treatment were categorized as responders and those reporting < 50% pain relief were categorized as non-responders. Rescue analgesia was provided by the topical application of a cream consisting of the combination of 3.33% doxepin and 0.05% capsaicin to the affected areas of PHN patients of both groups for at least 14 days, along with tramadol therapy. The rescue analgesia was extended to 4 weeks in patients of the non-responder group. The primary endpoints were measured using a numerical rating scale (NRS) at rest and with movement. Secondary endpoints included additional pain ratings such as global perceived effect (GPE), Neuropathic Pain Symptom Inventory scores (NPSI), daily sleep interference score (DSIS), quality of life (QOL) as per WHO QOL-BREF Questionnaire scores, patient and clinician ratings of global improvement. The 2 groups were compared on the basis of pain intensity scores, encompassing primary as well as secondary endpoints, and QOL after 28 days of the treatment regimen. Pain intensity scores measured by NRS (at resting and with movement), NPSI, and DSIS were consistently reduced (P < 0.001) over 28 days at varying intervals in both the groups, but the magnitude of reduction was higher in responders than non-responders. A concomitant improvement (P < 0.001) was observed in GPE on days 3, 14, and 28 as compared to the respective baseline scores in both the groups. Although the WHO QOL-BREF scores showed significant (P < 0.001) improvement in QOL of PHN patients at days 14 and 28 in both the groups, the magnitude of improvement was higher in responders as compared to non-responders. Significant improvement in pain intensity scores and QOL in non-responders is mainly attributed to the use of rescue analgesia for 28 days rather than recommended tramadol therapy. Treatment with tramadol 50 to 200 mg per day was associated with significant pain reduction in terms of enhanced pain relief, reduced sleep interference, greater global improvement, diminished side-effect profile, and improved QOL in PHN patients from North India. Further categorization of PHN patients may be helpful so that additional or alternative therapy may be prescribed to non-responders.

Central neuropathic pain after surgical resection in patients with spinal intramedullary tumor

Study designRetrospective case series. ObjectiveTo examine central neuropathic pain after surgical resection of intramedullary spinal cord tumor (IMSCT). Summary of background dataBecause of the rarity of IMSCT, there is little information about postoperative neuropathic pain after surgical resection. MethodsEighty-five of 105 patients treated surgically for IMSCT at our hospital between 2000 and 2008 completed the Neuropathic Pain Symptom Inventory (NPSI) and the short form (SF)-36 health inventory. The NPSI score was analyzed against the tumor type and the postoperative Japanese Orthopaedic Association (JOA) score for neurological symptoms. ResultsThe mean NPSI score of the patients was 13.5. The subscore for paresthesia/dysesthesia was significantly higher than the other subscores. Analysis of the NPSI scores by tumor type revealed no significant differences among patients with ependymoma, astrocytoma, and vascular tumors. The postoperative JOA score showed a weak negative correlation with the NPSI score in patients with thoracic spinal cord tumor, and no correlation in those with cervical tumor. In the 11 patients with hemangioblastoma, intense pain was reported at the level of the tumor, although postoperative paralysis was mild. All the postoperative SF-36 subscores of our study patients were significantly lower than the national average, and a significant negative correlation was observed between the SF-36 and the NPSI subscores. ConclusionNeuropathic pain after surgical resection reduces the QOL of patients with IMSCTs, and pain severity varies with the tumor's location and histological features, the severity of paralysis, and the location of pain relative to the tumor.