Painful Peripheral Neuropathy Research Articles

Serum Spexin Level Is Negatively Associated With Peripheral Neuropathy and Sensory Pain in Type 2 Diabetes

Background: Spexin is a novel peptide hormone and has shown antinociceptive effects in experimental mice. This study is aimed at evaluating the association of serum spexin level with diabetic peripheral neuropathy (DPN) and related pain in a Chinese population.Methods: We enrolled 167 type 2 diabetes mellitus (T2DM) including 56 patients without DPN (non-DPN), 67 painless DPN, and 44 painful DPN. Serum spexin was measured using ELISA. Logistic regression models were performed to analyze the independent effects of spexin on prevalence of DPN and painful DPN. In streptozotocin (STZ)-induced diabetic mice, mechanical pain threshold was measured using electronic von Frey aesthesiometer. Human peripheral blood mononuclear cells (PBMCs) were isolated and further stimulated with lipopolysaccharide without or with spexin. The gene expression was assayed by qPCR.Results: Compared with non-DPN, serum spexin level decreased in painless DPN and further decreased in painful DPN. The odds of DPN was associated with low spexin level in T2DM, which was similar by age, sex, BMI, and diabetes duration, but attenuated in smokers. The odds of having pain was associated with decreased spexin level in DPN, which was similar by age, sex, smoking status, and diabetes duration, but attenuated in normal weight. Furthermore, we observed that mechanical pain threshold increased in spexin-treated diabetic mice. We also found that lipopolysaccharide treatment increased the mRNA level of TNF-α, IL-6, and MCP-1 in human PBMCs, while spexin treatment prevented this increase.Conclusions: These results suggested that spexin might serve as a protective factor for diabetes against neuropathology and pain-related pathogenesis.

Reduced Thalamic Gamma Aminobutyric Acid (GABA) in Painless but not Painful Diabetic Peripheral Neuropathy.

Alterations in the structure, function, and microcirculation of the thalamus, a key brain region involved in pain pathways, have previously been demonstrated in patients with Painless- and Painful-diabetic peripheral neuropathy (DPN). However, thalamic neurotransmitter levels including GABA (inhibitory neurotransmitter) and glutamate (excitatory neurotransmitter) in different DPN phenotypes are not known. We performed a Magnetic Resonance Spectroscopy study and quantified GABA and glutamate levels within the thalamus, in a carefully characterised cohort of participants with Painless- and Painful-DPN. Participants with DPN (Painful- and Painless combined) had a significantly lower GABA:H2O ratio compared to those without DPN (Healthy volunteers [HV] and diabetes without DPN [No-DPN]). Participants with Painless-DPN had the lowest GABA:H2O ratio, which reached significance compared with HV and No-DPN, but not Painful-DPN. There was no difference in GABA:H2O in Painful-DPN compared with all other groups. A significant correlation with GABA:H2O and neuropathy severity was also seen. This study demonstrates that lower levels of thalamic GABA in participants with Painless-DPN may reflect neuroplasticity due to reduced afferent pain impulses. Whereas partially preserved levels of GABA in Painful-DPN may indicate that central GABAergic pathways are involved in the mechanisms of neuropathic pain in diabetes.

Painful diabetic peripheral neuropathy among Tunisian geriatric patients suffering from diabetes mellitus

Painful diabetic peripheral neuropathy among Tunisian geriatric patients suffering from diabetes mellitus

Terpenes from Cannabis sativa induce antinociception in a mouse model of chronic neuropathic pain via activation of adenosine A2A receptors.

Terpenes are small hydrocarbon compounds that impart aroma and taste to many plants, including Cannabis sativa. A number of studies have shown that terpenes can produce pain relief in various pain states in both humans and animals. However, these studies were methodologically limited and few established mechanisms of action. In our previous work, we showed that the terpenes geraniol, linalool, β-pinene, α-humulene, and β-caryophyllene produced cannabimimetic behavioral effects via multiple receptor targets. We thus expanded this work to explore the potential antinociception and mechanism of these Cannabis terpenes in a mouse model of chronic pain. We first tested for antinociception by injecting terpenes (200 mg/kg, IP) into male and female CD-1 mice with mouse models of chemotherapy-induced peripheral neuropathy (CIPN) or lipopolysaccharide-induced inflammatory pain, finding that the terpenes produced roughly equal antinociception to 10 mg/kg morphine or 3.2 mg/kg WIN55,212. We further found that none of the terpenes produced reward as measured by conditioned place preference, while low doses of terpene (100 mg/kg) combined with morphine (3.2 mg/kg) produced enhanced antinociception vs either alone. We then used the adenosine A2A receptor (A2AR) selective antagonist istradefylline (3.2 mg/kg, IP) and spinal cord-specific CRISPR knockdown of the A2AR to identify this receptor as the mechanism for terpene antinociception in CIPN. In vitro cAMP and binding studies and in silico modeling studies further suggested that the terpenes act as A2AR agonists. Together these studies identify Cannabis terpenes as potential therapeutics for chronic neuropathic pain and identify a receptor mechanism for this activity.

Omega-3 Fatty Acids Prevent Peripheral Neuropathy and Pro Inflammatory Adipose Tissue Macrophage Phenotype in High-Fat-Fed Mice

Obesity and/or consumption of a high fat diet is associated with the development of peripheral neuropathy (PN) which is characterized by changes in epidermal innervation and increased sensitivity in the extremities. Evidence indicates that omega-3 fatty acids prevent the development of PN and attenuate adipose inflammation, but the interaction of PN and adipose tissue macrophage (ATMΦ) phenotype have not been investigated. We hypothesized that a diet high in unsaturated fatty acids may prevent PN and adipose inflammation, despite the high fat content. PURPOSE: Assess the effects of omega-3 fatty acids on signs of PN and ATMΦ phenotype in high-fat-fed mice. Methods: Male C57Bl/6 mice were randomized to (n = 12-14/group): 10% low fat fish oil (10% FO); 54% high fat fish oil (54% FO); 10% low fat lard (10% L); or 54% high fat lard (54% L) for 14 weeks. PN was characterized by the von Frey test for hindpaw sensitivity at baseline then biweekly through week 14. After 14 weeks, intraepidermal nerve fiber density (IENFD) was quantified by immunohistochemistry of the hindpaw footpad skin using anti-PGP 9.5. The relative percentage of total macrophage cells (F4/80+CD11b+) and M1 (CD206-CD11c+) and M2 (CD206+CD11c-) cell populations in epididymal adipose were identified using flow cytometry. Group differences were identified by 2 x 2 factorial ANOVA. Pearson correlations were used to assess the relationship between hindpaw withdrawal threshold and ATMΦ. Results: 54% L (35.3 ± 1.0 g) had greater body mass compared to all other groups: 10% FO (26.5 ± 0.7, p < 0.001); 10% L (27.8 ± 0.6, p = 0.001); and 54% L (35.3 ± 1.0, p < 0.001). Similarly, fasting insulin was greater in 54% L (3.1 ± 0.4 ng/mL) compared to all other groups: 10% FO (1.0 ± 1.0, p < 0.001); 10% L (1.6 ± 0.2, p < 0.001), and 54% FO (1.0 ± 0.1, p < 0.001). Fasting glucose was greater in 54% L (225.8 ± 7.5 mg/dl) compared to 10% FO (216.1 ± 7.7, p =0.04) and 54% FO (182.6 ± 6.6, p = 0.03), but not 10% L (180.7 ± 17.1, p = 0.483). Following the same pattern as body mass and insulin, homeostatic model assessment of insulin resistance (HOMA-IR) was greater in 54% L (8.1 ± 1.1) compared to all other groups: 10% FO (2.2 ± 0.4, p < 0.001); 10% L (4.1 ± 0.6, p < 0.001); and 54% FO (2.2 ± 0.3, p < 0.001). Hindpaw sensitivity was greater in 54% L (0.08 ± 0.02 g) compared to 54% FO (0.19 ± 0.03, p = 0.02). IENFD was greater in 54% L (52.5 ± 2.2 fibers per mm) compared to 10% FO (44.1 ± 1.5, p = 0.04), but was not different from 10% L (49.7 ± 2.8, p = 0.47) or 54% FO (48.1 ± 3.0, p = 0.24). M1 ATMΦ percentage was greater in 54% L (11.7 ± 2.5 %) compared to all other groups: 10% L (3.8 ± 0.8, p = 0.001), 10% FO (5.2 ± 0.7, p = 0.014), and 54% FO (5.1 ± 0.6 %, p = 0.016). M2 ATMΦ percentage was greater in 10% L (59.7 ± 4.5 %) compared to all other groups: 10% FO (42.1 ± 5.0, p = 0.036), 54% L (41.4 ± 3.9, p = 0.027), and 54% FO (31.4 ± 3.6 %, p < 0.001), but there were no significant differences in M2 ATMΦ percentage in 54% L vs. 54% FO. There were no significant correlations between hindpaw sensitivity and M1 ATMΦ percentage, M2 ATMΦ percentage, or M1:M2 ratio. CONCLUSION: The negative metabolic effects of a high fat lard diet on body mass, glucose, insulin, and insulin resistance were prevented when the dietary fat source was omega-3 fatty acids instead of lard. Notably, mice fed a high fat lard diet had a higher percentage of the pro inflammatory M1 ATMΦ phenotype and developed signs of painful PN including hindpaw hypersensitivity and increased IENFD but these effects were prevented by omega-3 fatty acids in the 54% FO group, despite the high dietary fat content. Supported by the Southern Illinois University Edwardsville Vaughnie Lindsay New Investigator Award. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Investigating the safety and feasibility of osteopathic manipulative medicine in hospitalized children and adolescent young adults with cancer.

Children and adolescents young adults (AYAs) undergoing treatment for oncologic diagnoses are frequently hospitalized and experience unwanted therapy-induced side effects that diminish quality of life. Osteopathic manipulative treatment (OMT) is a medical intervention that utilizes manual techniques to diagnose and treat body structures. Few studies have investigated the implementation of OMT in the pediatric oncology outpatient setting. To date, no studies have investigated the safety and feasibility of OMT in the pediatric oncology inpatient setting. The objective of this study is to investigate the safety and feasibility of OMT in the pediatric oncology inpatient setting. This is a prospective, single-institution pilot study evaluating children and AYAs aged≥2 years to≤30 years with a diagnosis of cancer hospitalized at Riley Hospital for Children (RH) from September 2022 to July 2023. Approval was obtained from the Indiana University Institutional Review Board (IRB). Patients were evaluated daily with a history and physical examination as part of routine inpatient management. Patients who reported chemotherapy side effects commonly encountered and managed in the inpatient setting, such as pain, headache, neuropathy, constipation, or nausea, were offered OMT. Patients provided written informed consent/assent prior to receiving OMT. OMT was provided by trained osteopathic medical students under the supervision of a board-certified osteopathic physician and included techniques commonly taught in first- and second-year osteopathic medical school curricula. Safety was assessed by a validated pain (FACES) scale immediately pre/post-OMT and by adverse event grading per Common Terminology Criteria for Adverse Events (CTCAE) 24 h post-OMT. All data were summarized utilizing descriptive statistics. A total of 11 patients were screened for eligibility. All patients met the eligibility criteria and were enrolled in the study. The majority of patients were male (n=7, 63.6 %) with a median age of 18.2 years at time of enrollment (range, 10.2-29.8 years). Patients had a variety of hematologic malignancies including B-cell acute lymphoblastic leukemia (ALL) (n=5, 45.5 %), T-cell ALL (n=1, 9.1 %), acute myeloid leukemia (AML) (n=2, 18.2 %), non-Hodgkin's lymphoma (n=2, 18.2 %), and Hodgkin's lymphoma (n=1, 9.1 %). All patients were actively undergoing cancer-directed therapy at the time of enrollment. There were 40 unique reasons for OMT reported and treated across 37 encounters, including musculoskeletal pain (n=23, 57.5 %), edema (n=7, 17.5 %), headache (n=5, 12.5 %), peripheral neuropathy (n=2, 5.0 %), constipation (n=2, 5.0 %), and epigastric pain not otherwise specified (n=1, 2.5 %). Validated FACES pain scores were reported in 27 encounters. Of the 10 encounters for which FACES pain scores were not reported, 8 encounters addressed lower extremity edema, 1 encounter addressed peripheral neuropathy, and 1 encounter addressed constipation. The total time of OMT was documented for 33 of the 37 encounters and averaged 9.8 min (range, 3-20 min). Hospitalized children and AYAs with cancer received OMT safely with decreased pain in their reported somatic dysfunction(s). These findings support further investigation into the safety, feasibility, and efficacy of implementing OMT in the pediatric oncology inpatient setting and to a broader inpatient pediatric oncology population.

Patient satisfaction and patient accessibility in a small fiber neuropathy diagnostic service in the Netherlands: A single-center, prospective, survey-based cohort study.

Small fiber neuropathy (SFN) is a common cause of neuropathic pain in peripheral neuropathies. Good accessibility of diagnostics and treatment is necessary for an accurate diagnosis and treatment of SFN. Evidence is lacking on the quality performance of the diagnostic SFN service in the Netherlands. Our aim was to determine the patient satisfaction and -accessibility of the diagnostic SFN service, and to identify areas for improvement. In a single-center, prospective, survey-based cohort study, 100 visiting patients were asked to fill in the SFN patient satisfaction questionnaire (SFN-PSQ), with 10 domains and 51 items. Cut-off point for improvement was defined as ≥ 25% dissatisfaction on an item. A chi-square test and linear regression analyses was used for significant differences and associations of patient satisfaction. From November 2020 to May 2021, 98 patients with SFN-related complaints filled in the online SFN-PSQ within 20 minutes. In 84% of the patients SFN was confirmed, average age was 55.1 (52.5-57.8) years and 67% was female. High satisfaction was seen in the domains 'Waiting List Period', Chest X-ray', 'Consultation with the Doctor or Nurse Practitioner (NP)', 'Separate Consultation with the Doctor or NP about Psychological Symptoms', and 'General' of the SFN service. Overall average patient satisfaction score was 8.7 (IQR 8-10) on a 1-to-10 rating scale. Main area for improvement was shortening the 8-week period for receiving the results of the diagnostic testing (p < 0.05). General health status was statistically significant associated with patient satisfaction (p < 0.05). A good reflection of the high patient satisfaction and -accessibility of the SFN-service is shown, with important points for improvement. These results could help hospitals widely to optimize the logistic and diagnostic pathway of SFN analysis, benchmarking patient satisfaction results among the hospitals, and to improve the quality of care of comparable SFN services.

Comparison of the efficacy of spinal cord stimulation and dorsal root ganglion stimulation in the treatment of painful diabetic peripheral neuropathy: a prospective, cohort-controlled study.

The aim of this study was to compare the clinical outcomes of spinal cord stimulation (SCS) and dorsal root ganglion stimulation (DRG-S) in the treatment of painful diabetic peripheral neuropathy (PDPN). In this prospective cohort study, 55 patients received dorsal column spinal cord stimulation (SCS group) and 51 patients received dorsal root spinal cord stimulation (DRG-S group). The primary outcome was a Numerical Rating Scale (NRS) remission rate of ≥50%, and secondary outcomes included the effects of SCS and DRG-S on quality of life scores (EQ-5D-3L), nerve conduction velocity, and HbA1c, respectively. The percentage of NRS remission rate ≥ 50% at 6 months was 80.43 vs. 79.55%, OR (95% CI): 1.06 (0.38-2.97) in the SCS and DRG-S groups, respectively, and the percentage of VAS remission rate ≥ 50% at 12 months was 79.07 vs. 80.95%, OR (95% CI): 0.89 (0.31-2.58). Compared with baseline, there were significant improvements in EQ-5D and EQ-VAS at 6 and 12 months (p < 0.05), but there was no difference in improvement between the SCS and DRG-S groups (p > 0.05). Nerve conduction velocities of the common peroneal, peroneal, superficial peroneal, and tibial nerves were significantly improved at 6 and 12 months compared with the preoperative period in both the SCS and PND groups (p < 0.05). However, at 6 and 12 months, there was no difference in HbA1c between the two groups (p > 0.05). Both SCS and DRG-S significantly improved pain, quality of life, and lower extremity nerve conduction velocity in patients with PDPN, and there was no difference between the two treatments at 12 months.

Effect of Endovenous Ablation on Painful Peripheral Neuropathy Symptoms (P6-13.002)

Effect of Endovenous Ablation on Painful Peripheral Neuropathy Symptoms (P6-13.002)

Comparative study of pregabalin and carbamazepine in painful diabetic peripheral neuropathy at the tertiary care hospital

This study aimed to examine the effectiveness of carbamazepine as well as pregabalin in lowering the degree of pain associated with diabetic peripheral neuropathy. The results revealed noteworthy insights into the comparative effectiveness of these medications. Pregabalin, as a calcium channel modulator, has demonstrated efficacy in numerous neuropathic pain conditions. Beyond pain reduction, these drugs influence various aspects of daily functioning, emotional well-being, and social interactions is crucial for tailoring treatment approaches. The discussion explores Pregabalin medication stands out in improving overall quality of life of the patients. The results presented here indicated that among diabetic patients, age, HbA1c, DR, and the duration of their diabetes are related to considerably higher risks of DPN; however, BMI, smoking, TG, as well as TC did not show any evidence of an increased risk of DPN. The results of the study offer a scientific foundation for a deeper comprehension of the causes of peripheral neuropathy-complicated type 2 diabetes and the outcomes of preventative measures.Bottom of Form

The influence of genetic predisposition to oxidative stress on painful diabetic peripheral neuropathy: A mendelian randomization study.

Genetic predisposition to oxidative stress (OS) may influence the risk of Painful Diabetic Peripheral Neuropathy (PDPN). This study employed a Mendelian Randomization (MR) approach to investigate the causal relationship between genetic predisposition to OS and PDPN. Genetic instruments associated with OS biomarkers were selected as exposures. Summary-level data on PDPN was obtained from the largest available genome-wide association study (GWAS). MR analyses were conducted using the inverse-variance weighted (IVW) method, with sensitivity analyses employing the MR-Egger, weighted median, and MR-PRESSO approaches. Genetic predisposition to increased glutathione S-transferase (GST) activity was associated with a reduced risk of PDPN (OR=0.66, 95%CI: 0.49-0.89, P=0.006). Higher ascorbate levels conferred a protective effect against PDPN (OR=0.83, 95%CI: 0.71-0.97, P=0.018). No significant association was observed between genetic predisposition to OS biomarkers and PDPN severity. Genetic predisposition to increased GST activity and higher ascorbate levels protect against the development of PDPN, suggesting a causal relationship.

A review on comparative study of effectiveness of pregabalin and carbamazepine in painful diabetic peripheral neuropathy using mc gill's pain questionnaire

Diabetic neuropathy is a unique degenerative disorder of the peripheral nervous system that preferentially targets sensory axons and autonomic axons. The loss of sensory function that begins distally in the lower extremities is known as Diabetic neuropathy. It is characterized by burning pain, paresthesias and numbness in stocking glove pattern that progress proximally from the feet and hands. Diabetic neuropathy is a highly prevalent condition that substantially affects patients by increasing falls causing pain and reducing quality of life. The major risk factors for diabetic neuropathy is hyperglycemia. In addition to poor glycemic control, more-severe symptoms of diabetic neuropathy are associated with advanced age, hypertension, the duration of diabetes, dyslipidemia, smoking and heavy alcohol intake. Diabetic neuropathy is a major cause for disability of feet and hands globally. Anti-convulsants like pregabalin and carbamazepine are the medications used in the treatment of painful diabetic neuropathy.

Update on Treating Painful Diabetic Peripheral Neuropathy: A Review of Current US Guidelines with a Focus on the Most Recently Approved Management Options.

Painful diabetic peripheral neuropathy (DPN) is a highly prevalent and disabling complication of diabetes that is often misdiagnosed and undertreated. The management of painful DPN involves treating its underlying cause via lifestyle modifications and intensive glucose control, targeting its pathogenesis, and providing symptomatic pain relief, thereby improving patient function and health-related quality of life. Four pharmacologic options are currently approved by the US Food and Drug Administration (FDA) to treat painful DPN. These include three oral medications (duloxetine, pregabalin, and tapentadol extended release) and one topical agent (capsaicin 8% topical system). More recently, the FDA approved several spinal cord stimulation (SCS) devices to treat refractory painful DPN. Although not FDA-approved specifically to treat painful DPN, tricyclic antidepressants, serotonin/norepinephrine reuptake inhibitors, gabapentinoids, and sodium channel blockers are common first-line oral options in clinical practice. Other strategies may be used as part of individualized comprehensive pain management plans. This article provides an overview of the most recent US guidelines for managing painful DPN, with a focus on the two most recently approved treatment options (SCS and capsaicin 8% topical system), as well as evidence for using FDA-approved and guideline-supported drugs and devices. Also discussed are unmet needs for this patient population, and evidence for potential future treatments for painful DPN, including drugs with novel mechanisms of action, electrical stimulation devices, and nutraceuticals.

Different pain phenotypes are associated with anti-Caspr2 autoantibodies

Autoantibodies against contactin-associated protein 2 (Caspr2) not only induce limbic autoimmune encephalitis but are also associated with pain conditions. Here, we analyzed clinical data on pain in a large cohort of patients included into the German Network for Research in Autoimmune Encephalitis. Out of 102 patients in our cohort, pain was a frequent symptom (36% of all patients), often severe (63.6% of the patients with pain) and/or even the major symptom (55.6% of the patients with pain). Pain phenotypes differed between patients. Cluster analysis revealed two major phenotypes including mostly distal-symmetric burning pain and widespread pain with myalgia and cramps. Almost all patients had IgG4 autoantibodies and some additional IgG1, 2, and/or 3 autoantibodies, but IgG subclasses, titers, and presence or absence of intrathecal synthesis were not associated with the occurrence of pain. However, certain pre-existing risk factors for chronic pain like diabetes mellitus, peripheral neuropathy, or preexisting chronic back pain tended to occur more frequently in patients with anti-Caspr2 autoantibodies and pain. Our data show that pain is a relevant symptom in patients with anti-Caspr2 autoantibodies and support the idea of decreased algesic thresholds leading to pain. Testing for anti-Caspr2 autoantibodies needs to be considered in patients with various pain phenotypes.

Cognitive, behavioral, and psychological phenotypes in small fiber neuropathy: A case–control study

ObjectiveSmall fiber neuropathy (SFN) is a well-defined chronic painful condition causing severe individual and societal burden. While mood disorders have been described, cognitive and behavioral profiles of SFN patients has not been investigated. MethodsThirty-four painful SFN patients underwent comprehensive cognitive, behavioral, psychological, quality of life (QoL), and personality assessment using validated questionnaires. As control samples, we enrolled 36 patients with painful peripheral neuropathy (PPN) of mixed etiology and 30 healthy controls (HC). Clinical measures of neuropathic pain, duration, frequency, and intensity of pain at the time of assessment were recorded. Between-group and correlation analyses were performed and corrected for multiple comparisons. ResultsNo differences in clinical measures were found between SFN and PPN, and all groups had similar cognitive profiles. SFN patients showed higher levels of anxiety and alexithymia (p < .005) compared to PPN and HC, considering also pain intensity. Maladaptive coping strategies characterized both patient groups, but only SFN revealed higher levels of acceptance of pain (p < .05). Pain intensity and neuropathic symptoms were associated with mood, low QoL and catastrophism (p < .001), particularly, the higher the perceived pain intensity, the higher the use of maladaptive coping strategies (p < .001). The personality assessment revealed significant feelings of worthlessness and somatization traits both in SFN and PPN (p < .002 vs HC). Discussionsour results suggest that SFN patients had a normal-like cognitive profile, while their behavioral profile is characterized by mood disorders, alexithymia, maladaptive coping strategies, and poor QoL, as other chronic pain conditions, possibly related to pain intensity. Personality assessment suggests that somatization and feelings of worthlessness, which may worsen the neuropsychological profile, deserve clinical attention when considering patients' therapeutic approaches. At the same time, the high level of acceptance of pain is promising for therapeutic approaches based on psychological support.

Effect of Lower Extremity Nerve Decompression in Patients with Painful Diabetic Peripheral Neuropathy: The DNND Randomized, Observation Group- and Placebo Surgery-controlled Clinical Trial.

Evaluate the effect of nerve decompression on pain in patients with lower extremity painful Diabetic Peripheral Neuropathy (DPN). Currently, no treatment provides lasting relief for patients with DPN. Benefits of nerve decompression remain inconclusive. This double-blinded, observation- and same-patient sham surgery-controlled randomized trial enrolled patients aged 18-80 years with lower extremity painful DPN who failed one-year of medical treatment. Patients were randomized to nerve decompression- or observation-group (2:1). Decompression-group patients were further randomized and blinded to nerve decompression in either right or left leg and sham surgery in the opposite leg. Pain (11-point Likert score) was compared between decompression and observation groups and between decompressed versus sham legs at 12 and 56 months. Of 2987 screened patients, 78 were randomized. At 12 months, compared with controls (n=37), both right-decompression-group (n=22) and left-decompression-group (n=18) reported lower pain (mean difference for both, -4.46; [95% CI, -6.34 to -2.58 and -6.48 to -2.45 respectively]; P<0.0001). Decompressed and sham legs equally improved. At 56 months, compared with controls (n=14), pain was lower in both the right-decompression-group (n=20) (mean difference, -7.65; [95% CI, -9.87 to -5.44]; P<0.0001) and left-decompression-group (n=16) (mean difference, -7.26; [95% CI, -9.60 to -4.91]; P<0.0001). Mean pain score was lower in decompressed versus sham legs (mean difference, 1.57 [95% CI, 0.46 to 2.67]; P=0.0002). Although nerve decompression was associated with reduced pain, the benefit of surgical decompression needs further investigation since a placebo effect may be responsible for part or all of these effects.

Neuroprotective Effect of Polyvalent Immunoglobulins on Mouse Models of Chemotherapy-Induced Peripheral Neuropathy.

The occurrence of neuropathic pain in chemotherapy-induced peripheral neuropathy (CIPN) is a major dose-limiting effect of many commonly-used anticancer agents. Polyvalent human immunoglobulins (hIg), used in the treatment of several peripheral neuropathies, may alleviate neuropathic pain. The aim of this project was to investigate the preventive effect of hIg in two mouse models of CIPN, induced by vincristine (VCR, 100 µg/kg/d) and oxaliplatin (OXP, 6 mg/kg/3d). Human Ig were administered one day before the first injection of chemotherapy. The onset of CIPN and effects of hIg were assessed via functional tests and morphological analyses of sensory nerves. To evaluate the effect of hIg on chemotherapy cytotoxicity, viability assays were performed using hIg (0 to 12 mg/mL) combined with anticancer agents on human cancer cell lines. The preventive treatment with hIg alleviated tactile hypersensitivity and nerve injuries induced by VCR. It also alleviated tactile/cold hypersensitivities and nerve injuries induced by OXP. Treatment with hIg did not affect the cytotoxicity of either chemotherapy. Furthermore, in combination with VCR, hIg potentiated chemo-induced cell death. In conclusion, hIg is a promising therapy to prevent the onset of CIPN and potentiate chemotherapy effect on cancer, reinforcing the interest in hIg in the management of CIPN.

Effects of Neurodynamic Mobilization on Large Fibre Dysfunction in Painful Diabetic Peripheral Neuropathy: A Pilot Study

Effects of Neurodynamic Mobilization on Large Fibre Dysfunction in Painful Diabetic Peripheral Neuropathy: A Pilot Study

A case report on bortezomib-induced paralytic ileus

Bortezomib is the first anticancer proteasome inhibitor used in the initial treatment of multiple myeloma in combination with cyclophosphamide and dexamethasone. Subcutaneous and intravenous forms of bortezomib are available. The common adverse drug reactions (ADRs) associated with bortezomib include peripheral neuropathy, fatigue, neuralgia, dizziness, diarrhea, constipation, and abdominal pain. Paralytic ileus is a rare ADR of bortezomib. We report the case of a patient with multiple myeloma who developed paralytic ileus and presented with abdominal distension and constipation; all of which resolved with medical attention once the medication was stopped, indicating a clear causal link.

Mitotherapy prevents peripheral neuropathy induced by oxaliplatin in mice

Oxaliplatin (OXA) is an antineoplastic agent used for the treatment of cisplatin-resistant tumours, presenting lower incidence of nephrotoxicity and myelotoxicity than other platinum-based drugs. However, OXA treatment is highly associated with painful peripheral neuropathy, a well-known and relevant side effect caused by mitochondrial dysfunction. The transfer of functional exogenous mitochondria (mitotherapy) is a promising therapeutic strategy for mitochondrial diseases. We investigated the effect of mitotherapy on oxaliplatin-induced painful peripheral neuropathy (OIPN) in male mice. OIPN was induced by i.p. injections of oxaliplatin (3 mg/kg) over 5 consecutive days. Mechanical (von Frey test) and cold (acetone drop test) allodynia were evaluated between 7 and 17 days after the first OXA treatment. Mitochondria was isolated from donor mouse livers and mitochondrial oxidative phosphorylation was assessed with high resolution respirometry. After confirming that the isolated mitochondria were functional, the organelles were administered at the dose of 0.5 mg/kg of mitochondrial protein on days 1, 3 and 5. Treatment with OXA caused both mechanical and cold allodynia in mice that were significant 7 days after the initial injection of OXA and persisted for up to 17 days. Mitotherapy significantly prevented the development of both sensory alterations, and attenuated body weight loss induced by OXA. Mitotherapy also prevented spinal cord ERK1/2 activation, microgliosis and the increase in TLR4 mRNA levels. Mitotherapy prevented OIPN by inhibiting neuroinflammation and the consequent cellular overactivity in the spinal cord, presenting a potential therapeutic strategy for pain management in oncologic patients undergoing OXA treatment.