Risk Factors For Neuropathic Pain Research Articles

Vitamin D Deficiency as a Factor Associated with Neuropathic Pain in Multibacillary Type Morbus Hansen

Objective: Morbus Hansen (MH), caused by Mycobacterium leprae, is marked by neuropathic pain. Prior studies link low vitamin D levels to diabetic neuropathic pain, yet research on its role in MH-related neuropathic pain is limited. This study investigates the role of vitamin D deficiency in MH-related neuropathic pain. Materials and Methods: An analytical cross-sectional study was conducted among multibacillary (MB) MH patients at Prof. Dr. I.G.N.G. Ngoerah Hospital, Bali from April to August 2023. Neuropathic pain was assessed using the Douleur Neuropathique 4 (DN4) questionnaire, while serum 25(OH)D levels determined vitamin D status. The cutoff for deficiency was determined via ROC curve analysis. Results: Among 42 participants, those without neuropathic pain exhibited higher mean serum vitamin D levels than those with neuropathic pain (28.69 ± 8.16 vs. 22.11 ± 9.54 ng/ml; p=0.021). The ROC curve identified a cutoff value of 30.25 ng/ml, categorizing participants into vitamin D deficiency (<30.25 ng/ml) and non-deficiency (≥30.25 ng/ml) groups. Bivariate analysis revealed a heightened incidence of neuropathic pain among MH patients with serum vitamin D levels below the designated cutoff point (OR: 6.60; 95%CI: 1.484-29.355; p=0.022). Multivariate analysis indicated that two variables significantly correlated with neuropathic pain in MH patients: vitamin D deficiency (OR: 14.337; 95%CI: 2.431-84.542; p=0.003) and peripheral nerve enlargement (OR: 12.564; 95%CI: 2.096-75.307; p=0.006). Conclusion: Disparities in average vitamin D levels were observed between MH patients with and without neuropathic pain. Vitamin D deficiency, alongside peripheral nerve enlargement, emerged as significant risk factors for neuropathic pain in MH patients.

Pain types and risk factors in post-COVID-19.

This study aims to accurately evaluate pain lasting longer than three months and falls under the category of chronic pain and to determine the risk factors to follow up and treat properly and to develop appropriate diagnostic and treatment algorithms. Between March 2021 and December 2021, a total of 437 patients (162 males, 275 females; mean age: 44±14.6 years; range, 12 to 82 years) who were referred to the participating centers due to pain complaints and were diagnosed with post-COVID-19 condition according to the criteria defined by the World Health Organization (WHO) were included in the study. The patients were divided into three groups as nociceptive pain, neuropathic pain, and central sensitization, based on the physician's clinical evaluation and the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and Central Sensitization Inventory scores. The most common diagnosis was nociceptive pain followed by central sensitization. Patients with nociceptive pain had less pain. It was found that not exercising regularly, having a chronic disease and being a woman were risk factors for central sensitization, having thyroid disease before COVID-19, and defining the current pain as very severe were risk factors for neuropathic pain. In the evaluation of post-COVID-19 pain, neuropathic pain and central sensitization should be also considered in addition to nociceptive pain and the severity of pain, systemic diseases and physical activity should be questioned.

Risk factors of neuropathic pain in multiple sclerosis: a retrospective case-cohort study.

Pain is a common symptom in multiple sclerosis (MS), especially neuropathic pain, which has a significant impact on patients' mental and physical health and quality of life. However, risk factors that related to neuropathic pain, still remain unclear. The study aimed to explore the risk factors of neuropathic pain among MS patients. This retrospective study examined the consecutive patients diagnosed with MS in the Department of Neurology of Guangdong Provincial Hospital of Chinese Medicine between August 2011 and October 2022. Neuropathic pain was defined as "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system". Demographic and clinical features were obtained from the electronic system of the hospital. Our cohort revealed that the prevalence of patients with neuropathic pain in MS was 34.1%. The results indicated that the longer the spinal lesions, the greater the neuropathic pain risks (2-4: OR, 13.3(2.1-82), >5: OR, 15.2(2.7-86.8), p for tread: 0.037). Meanwhile, multivariate regression analysis showed that cervical and thoracic lesions (OR 4.276, 95% CI 1.366-13.382, P = 0.013), upper thoracic lesions (T1-T6) (OR 3.047, 95% CI 1.018-9.124, P = 0.046) were positively correlated with neuropathic pain, while basal ganglia lesions (OR 0.188, 95% CI 0.044-0.809, P = 0.025) were negatively correlated with neuropathic pain among MS patients. Extended spinal lesions (≥3 spinal lesions), cervical and thoracic lesions, upper thoracic lesions were independent risk factors of neuropathic pain among MS patients. Furthermore, our study found that the longer the spinal lesions, the greater the neuropathic pain risks.

The risk factors of neuropathic pain in neuromyelitis optica spectrum disorder: a retrospective case-cohort study

BackgroundNeuropathic pain is a common complication in neuromyelitis optica spectrum disorder (NMOSD), which seriously affects the quality of life of NMOSD patients, with no satisfactory treatment. And risk factors of neuropathic pain are still uncertain.ObjectiveTo investigate the risk factors of neuropathic pain in a NMOSD cohort.Materials and methodsOur study was a retrospective case-cohort study, the patients diagnosed with NMOSD in the Department of Neurology from the Second Affiliated Hospital of Guangzhou University of Chinese Medicine from January 2011 to October 2021 were screened. Inclusion criteria were: (1) patients diagnosed as NMOSD according to the International Panel for NMO Diagnosis (IPND) criteria, (2) the aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) test was performed. Patients without AQP4-IgG antibody were excluded. Clinical data, including sex, age of the first onset, symptoms of the first episode including neuropathic pain and attack types, localization of lesions of the first episode on Magnetic Resonance Imaging (MRI), Extended disability status Scale (EDSS) of the first onset, treatment of immunosuppression in the first acute phase, disease modifying therapy (DMT), treatment of neuropathic pain and APQ4-IgG status were collected from the hospital system database. Neuropathic pain was defined according to the International Association for the Study of Pain criteria and was described as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory system”.ResultsOne hundred nineteen patients were screened and finally 86 patients fulfilling the inclusion and exclusion criteria were enrolled in our study. The prevalence of neuropathic pain in patients with NMOSD was 43.0%. Univariate analysis showed that the factors associated with neuropathic pain were the age at the onset, the attack type of optic neuritis, the attack type of myelitis, length of spinal cord involvement, localization of thoracic lesion, optic lesion, upper thoracic lesions, lower thoracic lesions, extended spinal cord lesions (≥ 3 spinal lesions), extended thoracic lesions (≥ 4 thoracic lesions), intravenous immunoglobulin and mycophenolate mofetil. Multivariate regression analysis showed that extended thoracic lesions (OR 20.21 [1.18–346.05], P = 0.038) and age (OR 1.35 (1–1.81) P = 0.050) were independently associated with neuropathic pain among NMOSD patients and that gender (OR 12.11 (0.97–151.64) P = 0.053) might be associated with neuropathic pain among NMOSD patients.ConclusionExtended thoracic lesions (≥ 4 thoracic lesions), age and gender might be independent risk factors of neuropathic pain among patients with NMOSD. However, with a small sample size and predominantly female, caution must be applied and these results need validating in further cohorts.

Hyperglycemia Augmented Neuropathic Pain Involving the HMGB1/TLR4 Inflammatory Axis

<p>Peripheral neuropathy, accompanied by chronic neuropathic pain, is among the frequent and debilitating complications of diabetes. Hyperglycemia is a risk factor for neuropathic pain, but the pathological mechanisms are unclear. The high mobility group box 1 (HMGB1)/toll-like receptor 4 (TLR4) inflammatory axis is strongly implicated in the pathogenesis of neuropathic pain,so we examined how hyperglycemia influences the HMGB1/TLR4 axis and behavioural manifestations of hyperalgesia in the Sprague-Dawley rat sciatic nerve chronic constriction injury (CCI) model. Short-term hyperglycemia induced by streptozotocin significantly augmented mechanical allodynia and thermal hyperalgesia in CCI model rats compared to normoglycemic CCI model rats.These augmented nociceptive behaviours were associated with increased immune cell infiltration and activation, cytokine production and expression levels of TLR4 and HMGB1, as well as with reduced Sirt1 expression in spinal cord dorsal horn and sciatic nerve. High glucose also enhanced HMGB1/TLR4 inflammatory axis activity and cytokine production in lipopolysaccharide-stimulated RAW264.7 macrophages. Our results suggest that hyperglycemia predisposes individuals with peripheral nerve injury to neuropathic pain, in part through enhancement of Sirt1/HMGB1/TLR4 signalling and ensuing neuroinflammation.</p> <p> </p>

Neuropathic Pain after Adolescent Idiopathic Scoliosis Correction Surgery.

Study DesignProspective study.PurposeTo investigate the prevalence and the associated risk factors of chronic neuropathic pain symptoms using painDETECT questionnaire in adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF) surgery.Overview of LiteraturePost-lumbar surgery syndrome is a disease entity that describes neuropathic pain following spinal surgery. However, few studies have investigated the prevalence and risk factors for neuropathic pain in pediatric population undergoing corrective spinal surgery.MethodsForty AIS patients were recruited. Demographic, preoperative, and postoperative data were recorded. The magnitude and characteristics of postoperative pain were assessed using the painDETECT questionnaire through telephone enquiries at intervals of 2, 6, 12, and 24 weeks. Statistical analyses were followed by Pearson correlation test to determine the relationship between pain scores at 6, 12, and 24 weeks with the risk factors.ResultsBased on the painDETECT questionnaire, 90% of the patients had nociceptive pain, and 10% had a possible neuropathic pain component at 2 weeks postoperatively as per a mean painDETECT score of 7.1±4.5. Assessments at 6, 12, and 24 weeks showed that no patients had neuropathic pain with painDETECT scores of 4.4±3.2, 2.9±2.9, and 1.5±2.0, respectively. There was a significant correlation between total postoperative morphine use during 48 hours after the surgery and a tendency to develop neuropathic pain (p=0.022).ConclusionsChronic neuropathic pain was uncommon in AIS patients who had undergone PSF surgery. Higher opioid consumption will increase the possibility of developing chronic neuropathic pain.

Risk Factors for Neuropathic Pain Following Major Upper Extremity Amputation.

Active treatment (targeted muscle reinnervation [TMR] or regenerative peripheral nerve interfaces [RPNIs]) of the amputated nerve ends has gained momentum to mitigate neuropathic pain following amputation. Therefore, the aim of this study is to determine the predictors for the development of neuropathic pain after major upper extremity amputation. Retrospectively, 142 adult patients who underwent 148 amputations of the upper extremity between 2000 and 2019 were identified through medical chart review. All upper extremity amputations proximal to the metacarpophalangeal joints were included. Patients with a follow-up of less than 6 months and those who underwent TMR or RPNI at the time of amputation were excluded. Neuropathic pain was defined as phantom limb pain or a symptomatic neuroma reported in the medical charts at 6 months postoperatively. Most common indications for amputation were oncology (n = 53, 37%) and trauma (n = 45, 32%), with transhumeral amputations (n = 44, 30%) and shoulder amputations (n = 37, 25%) being the most prevalent. Neuropathic pain occurred in 42% of patients, of which 48 (32%) had phantom limb pain, 8 (5.4%) had a symptomatic neuroma, and 6 (4.1%) had a combination of both. In multivariable analysis, traumatic amputations (odds ratio [OR]: 4.1, p = 0.015), transhumeral amputations (OR: 3.9, p = 0.024), and forequarter amputations (OR: 8.4, p = 0.003) were independently associated with the development of neuropathic pain. In patients with an upper extremity amputation proximal to the elbow or for trauma, there is an increased risk of developing neuropathic pain. In these patients, primary TMR/RPNI should be considered and this warrants a multidisciplinary approach involving general trauma surgeons, orthopaedic surgeons, plastic surgeons, and vascular surgeons.

Risk Factors for Neuropathic Pain in Middle-Aged and Elderly People: A Five-Year Longitudinal Cohort in the Yakumo Study.

To determine the risk factors for new neuropathic pain (NeP) after five years in healthy middle-aged and elderly volunteers. Prospective longitudinal cohort study (Yakumo study). Clinical evaluation in a health checkup. A total of 366 people (male N = 146, female N = 220, average age = 63.5 years) who did not have NeP in 2013 were examined. NeP was diagnosed based on a painDETECT questionnaire score ≥13. Body mass index (BMI), comorbidity, low back pain (LBP), sciatica, physical ability, grip and back muscle strength, osteoporosis, sarcopenia, frailty, spinal alignment, and quality of life (QOL) with the SF36 in 2013 were compared between NeP(+) and NeP(-) subjects in 2018 using multivariate logistic regression analysis. The NeP(+) rate in 2018 was 5.2%, with no significant differences in age and gender. NeP(+) subjects had significantly lower BMI, severe sciatica, poor gait ability, higher rates of osteoporosis and sarcopenia, greater lumbar kyphosis and spinal inclination, and poorer mental health in 2013. Poor gait ability (odds ratio [OR] = 8.05), low BMI (OR = 2.31), lumbar kyphosis (OR = 1.38), low percentage of the young adult mean (OR = 1.15), and low mental QOL (OR = 1.06) were identified as significant and independent risk factors for new NeP after five years. This longitudinal cohort study identified five independent risk factors for development of new NeP after five years, with related factors of spinal inclination, sarcopenia, and sciatica. New NeP may be prevented by intervention or treatment of these factors at an early stage in relatively healthy middle-aged and elderly people.

Risk Factors of Neuropathic Pain after Total Hip Arthroplasty.

PurposePain caused by osteoarthritis is primarily nociceptive pain; however, it is considered that a component of this pain is due to neuropathic pain (NP). We investigated the effects of total hip arthroplasty (THA) in patients with NP diagnosed by the PainDETECT questionnaire.Materials and MethodsOne hundred sixty-three hips (161 patients) were evaluated. All patients were asked to complete the PainDETECT questionnaire based on their experience with NP, and clinical scores were evaluated using the Japanese Orthopaedic Association (JOA) Hip Score before and after THA.ResultsThe patients of 24.5% reported NP before THA; 5.5% reported NP 2 months after THA. Prior to THA, there was no significant correlation between the PainDETECT score and the radiographic severity; however, there was a significant correlation between the PainDETECT score and JOA score. NP at 2 months after THA was not significantly correlated with pain scores at 1 week after THA; however, a significant correlation was observed between the preoperative pain score and NP at 2 months after THA.ConclusionTHA was useful for relieving nociceptive pain and for relieving NP in patients with hip osteoarthritis. Preoperative pain was a risk factor for NP after THA. Controlling preoperative pain may be effective for reducing postoperative NP.

Risk factors of neuropathic pain after thoracic surgery.

This study aimed to clarify the incidence and risk factors of neuropathic pain after thoracic surgery, focusing especially on patients who underwent complete video-assisted thoracoscopic surgery (VATS). We retrospectively identified 185 patients who underwent thoracic surgery at our hospital over a 2-year period. Logistic regression analysis was used to analyze the association of various factors with postoperative neuropathic pain. Forty-eight (25.9%) patients developed postoperative neuropathic pain, and 9 (18.8%) of these patients reported persistent pain 1 year postoperatively. The median interval from surgical treatment to the onset of neuropathic pain was 7 days, and the duration was 50 days. Multivariate logistic regression analysis revealed a significant positive correlation between postoperative neuropathic pain and preoperative use of hypnotic medication [odds ratio (OR), 5.45; 95% confidence interval (CI); 2.52-12.17] and duration of surgery ≥2.5 hours (OR, 2.72; 95% CI, 1.27-6.09), and a significant negative association with the complete VATS approach (OR, 0.18; 95% CI, 0.073-0.42). Preoperative use of hypnotic medication, the thoracotomy approach, and duration of surgery ≥2.5 hours are associated with increased risk of neuropathic pain after thoracic surgery. The complete VATS approach could decrease the incidence of postoperative neuropathic pain, regardless of the duration of surgery.

Systematic review and meta-analysis of genetic risk factors for neuropathic pain.

Neuropathic pain (NP) is an increasingly common chronic pain state and a major health burden, affecting approximately 7% to 10% of the general population. Emerging evidence suggests that genetic factors could partially explain individual susceptibility to NP and the estimated heritability in twins is 37%. The aim of this study was to systematically review and summarize the studies in humans that have investigated the influence of genetic factors associated with NP. We conducted a comprehensive literature search and performed meta-analyses of all the potential genetic variants associated with NP. We reviewed 29 full-text articles and identified 28 genes that were significantly associated with NP, mainly involved in neurotransmission, immune response, and metabolism. Genetic variants in HLA genes, COMT, OPRM1, TNFA, IL6, and GCH1, were found to have an association with NP in more than one study. In the meta-analysis, polymorphisms in HLA-DRB1*13 (odds ratio [OR], 2.96; confidence interval [CI], 1.93-4.56), HLA-DRB1*04 (OR, 1.40; CI, 1.02-1.93), HLA-DQB1*03 (OR, 2.86; CI, 1.57-5.21), HLA-A*33 (OR, 2.32; CI, 1.42-3.80), and HLA-B*44 (OR, 3.17; CI, 2.22-4.55) were associated with significantly increased risk of developing NP, whereas HLA-A*02 (OR, 0.64; CI, 0.47-0.87) conferred reduced risk and neither rs1799971 in OPRM1 (OR, 0.55; CI, 0.27-1.11) nor rs4680 in COMT (OR, 0.95; CI, 0.81-1.13) were significantly associated with NP. These findings demonstrate an important and specific contribution of genetic factors to the risk of developing NP. However, large-scale replication studies are required to validate these candidate genes. Our review also highlights the need for genome-wide association studies with consistent case definition to elucidate the genetic architecture underpinning NP.

TRPA1 polymorphisms in chronic and complete spinal cord injury patients with neuropathic pain: a pilot study.

Pilot study. Single-nucleotide polymorphisms (SNPs) in TRPA1 gene are related to the etiology of chronic pain. The study is a pilot study with the primary objective of analyzing these SNPs in Spanish patients with chronic and complete spinal cord injury (SCI) and neuropathic pain (NPP). Asepeyo Hospital Department of Chronic and Complete SCI. Twelve patients with chronic and complete SCI and NPP, and 12 patients with chronic and complete SCI with no pain were reviewed. International Spinal Cord Injury Pain Classification (LANSS) and visual analog score (VAS) were chosen to classify pain syndrome. SNPs were identified by melting analysis after DNA amplification with real-time fluorescence PCR. There were differences in rs11988795 variant: GG homozygous (p = 0.01) and G allele (p = 0.001) were more frequent in SCI patients with no pain. There were differences in rs13255063 variant: TT homozygous were prevalent (p = 0.03) in patients with NPP. Until now this is the first study to show a description of TRPA1 SNPs in Spanish patients with chronic and complete SCI and NPP. These results suggest that GG genotype in rs11988795 variant and G allele could be protective factors against NPP. TT genotype in rs13255063 variant could be a risk factor for NPP. Neuropathic pain after spinal cord injuries may have genetic contributions.

The Prevalence Of Acute Neuropathic Pain After Surgery In Hospital Of Lithuanian University Of Health Sciences Kaunas Clinics

Background. Acute neuropathic pain can be one of the post-surgical pain components, which is often under-recognized and complicated to treat. The prevalence of pain with neuropathic characteristics in general population is about 6 – 8%. Moreover, it might to progress and become as a persistent pain and cause a disability. This type of study has never been performed in Lithuania. Methods. Investigators conducted a survey, which consisted of the following visual and verbal analogue and Dolour Neuropathique 4 scales to identify pain intensity and neuropathic pain after surgery. Risk factors of neuropathic pain were evaluated with Hospital Anxiety and Depression scale, demographic characteristics and data, which represents possible risk factors. Results. The survey included 170 participants: 68 males (40%) and 102 females (60%). Average age of patients was 59.66 years (SD 15.9). During the first day after surgery 7.1% patients felt neuropathic pain, on the second day – 8.2%, and the third postoperative day – 7.6% of patients. A prevalence of neuropathic pain depends on gender and anxiety before surgery. Conclusion. A prevalence of acute neuropathic pain after surgery in Hospital of Lithuanian University of Health Sciences is 7 – 8%. The risk factors of neuropathic pain development are patient’s gender and anxiety before surgical procedure.

Evaluation of the neuropathic pain in the smokers.

Nicotine addiction is one of the most important causes of the general failure of treatment and keeping the habit of smoking. Peripheral neuropathy is a leading factor of smoking. This study aimed to analyze the association of neuropathic pain and addiction levels of individuals. The study was performed on the day on which the smokers visited the hospital for any reason. The Douleur Neuropathique 4 (DN-4) Scale and Fagerström Addiction Survey were administered to the individuals after obtaining their consent. In total, 444 individuals were included in the study, and 57.2% of them were males (n = 254). The age average of the individuals with neuropathic pain (46.4±12.3 years) was significantly higher than that of those without pain. The individuals with pain smoked approximately 31.8±18.3 packet/year cigarettes, whereas those without pain smoked approximately 22.4 ± 15.5 packet/year cigarettes; the difference was significant statistically (p<0.05). According to multivariate logistic regression analysis with the backward elimination method, the existence of pain was found to be PR = 2.22 (95% GA, 1.26-3.91) in terms of sex, DM existence was found to be PR = 1.97 (95% GA, 1.02-3.81), and for each standard deviation increase (2.7) in Fagerström scale, PR was 1.29 (95% GA, 1.14-1.46). Smoking is a risk factor for neuropathic pain. In our study, the possibility of neuropathic pain increases as the duration of smoking and addiction level increase, and with diabetes, this rate increases even more. It is extremely important that the smokers should be informed regarding these facts and possibilities.

The Effect of Carpal Tunnel Release on Neuropathic Pain in Carpal Tunnel Syndrome.

Purpose The aim of this study was to determine the risk factors of neuropathic pain (NP) in the patient with carpal tunnel syndrome (CTS) before and after the carpal tunnel release. Materials and Methods One hundred and two CTS patients were enrolled in the study. The pain score was measured by the visual analogue score. NP was determined by the painDETECT (PD) questionnaire. All subjects were divided into 3 groups at 12 weeks after surgery: an Improved, Unchanged, and Worsened group. The risk factors of worsening NP after surgery were evaluated. Results We found that 36% and 18% of patients with CTS had neuropathic pain before and 12 weeks after surgery, respectively, and pain was significantly stronger than in those without NP. The PD score of eight hands worsened after surgery. In the “Improved group,” the average age at the surgery was younger and the pain score was lower than in the “Unchanged group.” Conclusions. The surgery was very effective on NP of CTS; however, the PD in 7% of hands worsened after surgery. Risk factors before surgery that predicted worse NP after surgery were found to be a younger age, weaker pain, and the absence of night pain.

Risk factors for neuropathic pain in diabetes mellitus.

According to the International Diabetes Federation, diabetes mellitus (DM) is estimated to affect around 415 million adults worldwide, roughly 8.8% of the adult population, with the figure projected to rise to over 600 million by 2040.20 Regional prevalence varies from 3.2% in Africa to 12.9% in North America. Diabetes mellitus is associated with a number of chronic sequelae and around 50% of people with DM go on to develop polyneuropathy.35 This condition has a variety of clinical manifestations, which are grouped into positive symptoms including dysesthesia (abnormal sense of touch), tingling and itching, and negative symptoms including numbness, muscle weakness, and trouble with balance. Up to 25% of people with diabetic neuropathy (DN) also develop neuropathic pain (NP).39 Neuropathic pain is defined by the International Association for The Study of Pain as “pain directly caused by a lesion or disease affecting the somatosensory system.”12,22 Symptoms of painful diabetic neuropathy (PDN) include those described above for nonpainful DN with additional “burning,” “electric shocks,” “stabbing,” and “pins and needles” symptoms all being described. Painful diabetic neuropathy is associated with increased distress and poor quality of life compared with nonpainful DN, DM, and the general population38 including depression, anxiety, and sleep disturbance.15 In addition, an association has been described with reduced productivity and employability at work compared with nonpainful DN.37 The combination of these factors places a large economic burden on patients and health care services,10 a situation likely to grow steadily worse with the aforementioned projected rise in DM prevalence. This situation is further exacerbated by the fact that 13% of patients with PDN do not report their symptoms to primary care, and 39% of patients with PDN have never received treatment.8 Even for those patients who do attend primary and secondary care for their diabetes, pain is not a symptom that is always included in clinical assessments. Furthermore, not all patients with DN develop PDN, and the reasons for this are unclear. Understanding the risk factors for PDN will go some way to resolving this and will also help to inform management and prevention of this painful condition by health care services. Any factor that increases the risk of DM or DN is likely to be a risk factor for PDN. However, it is the specific nature and magnitude of the risk that remains unclear and is the focus of this topical review.

Independent Risk Factors for Positive and Negative Symptoms in Patients with Diabetic Polyneuropathy

ABSTRACTPatients with diabetes occasionally develop diabetic polyneuropathy (DPN), which is characterized by both positive symptoms such as pain and negative symptoms such as numbness/dysesthesia. However, these symptoms have always been collectively analyzed to determine their risk factors. This study aimed to independently analyze the risk factors for neuropathic pain and numbness/dysesthesia in DPN patients. In total, 298 patients with diabetes (age: 61.1 ± 10.4 years; 176 male) were included. The relationships among the incidence of DPN and its clinical parameters were determined using logistic regression models. Then, the statistical model was applied in two groups of DPN patients: those with pain only or both pain and the negative symptoms (pain group; n = 25) and those with the negative symptoms only or both pain and the negative symptoms (numbness/dysesthesia group; n = 60). All logistic regression models were adjusted for the duration of diabetes, glycosylated hemoglobin levels, and age. The depression score was higher for patients with DPN than for those without, although it did not reach an abnormal level. An abnormal Achilles tendon reflex (ATR) and insulin treatment, but not smoking, hypertension, hyperlipidemia, and diabetic retinopathy, were associated with DPN. Furthermore, female sex and an abnormal ATR and insulin treatment were significant clinical features in the pain and numbness/numbness groups, respectively. Overweight and obesity were the common clinical features in both groups. We conclude that the positive and negative symptoms of DPN possibly have independent risk factors, suggesting different underlying mechanisms and the need for separate diagnosis and treatment.

The clinical characteristics of neuropathic pain in patients with total brachial plexus avulsion: A 30-case study

Neuropathic pain in patients with total brachial plexus avulsion has always been a sophisticated problem in clinical practice. ObjectivesFor further researches on objective diagnosis, alleviation or even cure of neuropathic pain, we need to conclude the basic clinical features including pain intensity, distribution, type and possible risk factors. MethodsThirty cases of patients with total brachial plexus avulsion were included and their baseline information was collected. Pain was evaluated by Present Pain Index using a visual analog scale; Douleur Neuropathique 4 was used for screening neuropathic pain. For more detailed pain description, the Neuropathic Pain Symptoms Inventory questionnaire and a picture showing the exact pain district were both fulfilled by all the eligible participants. The relationship between neuropathic pain and basic information, injury conditions, accompanied conditions and quality of life was tested. ResultsAll the participants were male in both groups. The neuropathic pain group contained 22 patients (73.33%) with the mean age of 30.18±9.47; while 29.00±7.95 in the other group. Patients with neuropathic pain presented variously in pain degree, location, type and time phase, according to the results of the Neuropathic Pain Symptoms Inventory questionnaire. Nevertheless, most pain distributed on the region of hand. Among several related factors, alcohol abuse may be possible risk factors of neuropathic pain (p=0.03). Quality of life was significantly affected by pain (p<0.01). ConclusionNeuropathic pain in patients with total brachial avulsion was characterized with heterogeneity in pain distribution, intensity, type and also time phase. Bad life habits might be risk factors associated with neuropathic pain. Neuropathic pain might affect quality of life of the patients with total brachial plexus avulsion remarkably.

Neuropathic pain as part of chronic widespread pain: environmental and genetic influences.

Chronic widespread pain (CWP) has complex aetiology and forms part of the fibromyalgia syndrome. Recent evidence suggests a higher frequency of neuropathic pain features in those with CWP than previously thought. The aim of this study was to determine the prevalence of neuropathic pain features in individuals with CWP and to estimate the influence of genetic and environmental factors on neuropathic pain in CWP. Validated questionnaires (the London Fibromyalgia Screening Study questionnaire and PainDETECT questionnaire) were used to classify twins as having CWP and neuropathic pain, respectively. The prevalence of CWP was 14.7% (n = 4324), and of the 1357 twins invited to complete neuropathic pain screening, 15.9% of those having CWP demonstrated features of neuropathic pain. Neuropathic pain was found to be heritable (A = 37%; 95% confidence interval [CI]: 23%-50%) with unique environmental factors accounting for 63% (95% CI: 49%-79%) of the variance. Heritability of neuropathic pain and CWP were found to be correlated, 0.54 (95% CI: 0.42-0.65). Increasing age, raised body mass index, female gender, and smoking were all risk factors for neuropathic pain (P < 0.05), and CWP (P < 0.05). High socioeconomic status showed negative correlation with neuropathic pain (P = 0.003) and CWP (P = 0.001). Bivariate analysis of the 2 pain traits revealed that genetic predisposition to neuropathic pain is shared with that for CWP. This is the first study to provide formal heritability estimates for neuropathic pain in CWP. The findings suggest that at least some of the genetic factors underlying the development of neuropathic pain and CWP are the same.

Neuropathic Pain Following Sagittal Split Ramus Osteotomies of the Mandible: Prevalence, Risk Factors, and Clinical Course

Neuropathic pain (NPP) is characterized by paradoxical pain and abnormal sensory function following sensory nerve injury. NPP has been reported as a complication of many surgical procedures including sagittal split ramus osteotomies (SSRO) of the mandible.1 While studies have examined the prevalence of and risk factors for NPP following thoracic, abdominal, gastrointestinal and gynecologic surgeries, there is limited knowledge about NPP following SSRO of the mandible. Prevalence estimates have ranged from 5-10%, but these have been derived from just a few small case series.2 Our current understanding of NPP following SSRO has been further limited by the methodologic heterogeneity of studies and a lack of consensus regarding the characteristics of NPP. Therefore we sought to identify the prevalence of, risk factors for, and clinical course of NPP following SSRO in a large group of patients.