Association of Neuropathic Pain Symptoms with Sensitization Related Symptomatology in Women with Fibromyalgia

The polymorphism Val158Met in the COMT gene: disrupted dopamine system in fibromyalgia patients?

ABSTRACT

The single-nucleotide polymorphism (SNP) rs4680 in the catechol-O-methyltransferase gene ( COMT ) is a missense variant (Val158Met) associated with altered activity of the COMT enzyme and suggested as a predictive feature for developing some chronic pain conditions. However, there are controversial results on its role in fibromyalgia (FM). Here, the SNP Val158Met was analyzed in 294 FM patients (without comorbidities) and 209 healthy controls (without chronic pain). The concurrent impact of Val158Met genotypes and FM comorbid disorders (depression and sleep impairment) on FM risk were tested. In addition, the genotypic distribution of FM patients in relation to pain intensity was evaluated. The G allele (Val) resulted in being more represented in the FM group (57.8%) compared with the control group (48.8%; P = 0.037). Logistic regression highlighted that having the G/G (Val/Val) homozygous genotype was associated with 2 times higher risk of having FM compared with the A/A (Met/Met) carriers ( P = 0.038), whereas depression and sleep impairment increased FM risk by 12 and 8 times, respectively ( P < 0.001). However, considering only the FM patient group, the A/A homozygous genotype was significantly associated with severe pain intensity ( P = 0.007). This study highlighted associations between the SNP Val158Met and both FM and pain intensity, suggesting a link between dopaminergic dysfunction and vulnerability to chronic pain. Further studies should explore this SNP in FM patients in conjunction with COMT enzymatic activity and other symptoms connected with the dopaminergic system such as depression or sleep impairment.

Association of OPRM1 rs1799971, HTR1B rs6296 and COMT rs4680 polymorphisms with clinical phenotype among women with fibromyalgia

To investigate the association between three selected pain polymorphisms and clinical, functional, sensory-related, psychophysical, psychological or cognitive variables in a sample of women with fibromyalgia (FMS). One hundred twenty-three (n = 123) women with FMS completed demographic (age, height, weight), clinical (years with pain, intensity of pain at rest and during daily living activities), functional (quality of life, physical function), sensory-related (sensitization-associated and neuropathic-associated symptoms), psychophysical (pressure pain thresholds), psychological (sleep quality, depressive and anxiety level) and cognitive (pain catastrophizing, kinesiophobia) variables. Those three genotypes of the OPRM1 rs1799971, HTR1B rs6296 and COMT rs4680 single nucleotide polymorphisms were obtained by polymerase chain reactions from no-stimulated whole saliva collection. No significant differences in demographic, clinical, functional, sensory-related, psychophysical, psychological and cognitive variables according to OPRM1 rs1799971, HTR1B rs6296 or COMT rs4680 genotype were identified in our sample of women with FMS. A multilevel analysis did not either reveal any significant gene-to-gene interaction between OPRM1 rs1799971 x HTR1B rs6296, OPRM1 rs1799971 x COMT rs4680 and HTR1B rs6296 x COMT rs4680 for any of the investigated outcomes. This study revealed that three single nucleotide polymorphisms, OPRM1 rs1799971, HTR1B rs6296 or COMT rs4680, mostly associated with chronic pain were not involved in phenotyping features of FMS. Potential gene-to-gene interaction and their association with clinical phenotype in women with FMS should be further investigated in future studies including large sample sizes.

The association of self-reported symptoms of central sensitization and sleep disturbances in neuropathic pain

Introduction

Patients with neuropathic pain (NP) report a higher impairment of quality of life and sleep than patients with chronic pain without neuropathic characteristics. These include somatosensory peculiarities like allodynia, a surrogate marker for central sensitization.

Objectives

This study aimed to investigate the relation between symptoms of central sensitization and sleep disturbances in patients with NP.

Methods

Within this cross-sectional study, data sets of 3339 patients with chronic NP syndromes (painful diabetic polyneuropathy, n = 543; postherpetic neuralgia, n = 1480) or complex regional pain syndromes (CRPS, n = 1316) were analyzed. Neuropathic pain symptoms were assessed with the painDETECT questionnaire (PD-Q), depression with the Patient Health Questionnaire-9, and sleep impairment with items of the Medical Outcomes Study Sleep Scale in 4 subscales. The association of demographic/clinical data, somatosensory phenotype, depression, and pain intensity with sleep impairment was assessed by unadjusted Spearman correlation analyses and multivariable regression analyses.

Results

Sleep impairment was observed in all pain aetiologies although with some significant differences in the single sleep items. The intensity of the individual PD-Q items differed to some extent between the 3 pain entities, whereas the PD-Q sum score was similar. Thermal hyperalgesia and burning assessed by the PD-Q were significantly associated with sleep disturbance, adequacy, and quantity but not with sleep somnolence. Only depression and self-reported allodynia had a significant relation to all 4 sleep elements.

Conclusion

Beside depression, allodynia as a surrogate marker hints to a possible impact of central sensitization on the sleep disruption of patients with NP.

Clinical characteristics of ankylosing spondylitis patients depending on neuropathic pain

Introduction

Neuropathic pain (NP) in ankylosing spondylitis (AS) is an important factor that complicates patients' everyday activities and leads to a decrease of life quality. Detection and diagnosis of NP can be facilitated by the use of screening instruments, and the comparative assessment of the sensitivity of different scales is important for improving the diagnosis and personalizing the treatment of AS.The aim of the study was to analyze prevalence of NP in patients with AS and clinical features of AS patients depending on the presence of NP.

Material and methods

We examined 94 patients with NP and 48 patients without pain in AS using the following questionnaires: LANSS, DN4, StEP, BASFI, BASMI, BASDAI, HAQ, ASAS HI/EF and BAS-G.

Results

The prevalence of NP according to LANSS was 51.7% in women and 32.7% in men (p = 0.048); according to DN4 - 58.6% and 32.7%, respectively (p = 0.010). Disease activity and functional disability of the patients were higher in the group of patients with NP than in the group of patients without NP according to the BASDAI, BASFI, BASMI, HAQ, ASAS HI/EF and BAS-G. Significance of differences between groups was at the level of p < 0.01.

Conclusions

The prevalence of NP in AS is alarmingly high. Even with low scores on screening scales, patients showed signs of NP, which may indicate higher prevalence of NP. Neuropathic pain is more associated with the activity of the disease, greater loss of functional capacity and a decrease in indicators of the general state of health, which allows it to be considered as an aggravating factor regarding these manifestations.

[Assessment of neuropathic pain among women with suspected endometriosis based on two specific surveys]

OBJECTIVES

A significant proportion of women with suspected endometriosis present neuropathic pain. The aim of this study is to assess this prevalence and the relevance of specific tests used.

METHODS

This is a single-center retrospective study in the CHI of Poissy Saint Germain en Laye with patients who were referred for suspected endometriosis and who benefited from evaluation of neuropathic pain by two distinct questionnaires. The PAINdetect was evaluated by a series of 7 questions scored from 0 to 5 with a positive test if score>18. For the DN4, 7 binary questions were asked and 3 other questions were related to the clinical examination with a positivity threshold reached if score≥4 and in the absence of clinical examination if score≥3.

RESULTS

From November 2020 to June 2022, 57 patients were examined with a prevalence of neuropathic pain (one of the two test positive) evaluated at 36.8%. PAINdetect and DN4 positivity rates were at 26.8% and 30.9%. A discordance was found in 14.8% of cases with a kappa coefficient calculated at 0.63. There was a significant association between radiological examination and neuropathic pain with more neuropathic pain when the radiological examination was negative (P=0.03). The myofascial syndrome was present in only 59.5% of the patients and wasn't associated with neuropathic pain (P=1.00).

CONCLUSION

Prevalence of neuropathic pain in case of suspected endometriosis appears to be high. This need to be confirmed in a multicenter study with also assessment of the validity of the two diagnostic tests.

Neuropathic Pain Was Associated with Central Sensitivity Syndrome in Patients with Preoperative Lumbar Spinal Stenosis Using the painDETECT and Central Sensitization Inventory Questionnaires: A Cross-Sectional Study

Background

Lumbar spinal stenosis (LSS) patients have been reported to have neuropathic pain and central sensitivity syndrome (CSS). These associations have been reported in other diseases but are unknown in preoperative LSS patients. We aimed to investigate the association between neuropathic pain and CSS in preoperative LSS patients using the painDETECT and the Central Sensitization Inventory (CSI) questionnaires.

Methods

This cross-sectional study was conducted from November 2021 to March 2022. The data were collected regarding demographics and pain, including neuropathic pain, numbness, LSS severity, physical function, quality of life, and CSS. Patients were divided into two groups, patients with acute and chronic pain, and further classified into three categories based on the clinical phenotype of patients in each group. Independent variables included age, gender, type of LSS (bilateral or unilateral symptoms), Numerical Rating Scale of leg pain, CSI, and the Zurich Claudication Questionnaire (ZCQ) for symptom severity and physical function. The dependent variable was painDETECT. Multiple regression analysis using the forced entry method examined the association between painDETECT and CSI.

Results

Of the 119 patients with preoperative LSS, 106 were included. The mean age of the participants was 69.9 years, and 45.3% were female. Neuropathic pain was present in 19.8%, and CSS was present in 10.4%. The CSI (β = 0.468, p < 0.001) and ZCQ for symptom severity (β = 0.304, p < 0.01) were significantly associated with the painDETECT, explaining 47.8% of the variance in the painDETECT score.

Conclusions

There is an association between neuropathic pain and CSS in patients with preoperative LSS using the painDETECT and CSI questionnaires.

Possible Neuropathic Pain in Clinical Practice-Review on Selected Diagnostic Tools and Its Further Challenges

BACKGROUND

Neuropathic pain (NeP) is a wide group of conditions provoked by many different causes and with different patterns. The creation of a grading system was intended to determine the level of certainty that the pain is of neuropathic nature.

METHODS

The aim of this review is to update previously published data on some NeP questionnaires and their measurement properties. The selection of articles is based on the basic neurological units. To assess the usefulness and credibility of the questionnaires, the authors searched for a commonly used measure of reliability, as well as sensitivity and specificity.

RESULTS

Studies regarding the usefulness and credibility of questionnaires used in NeP were realized. Different patient cohorts, etiologies and sample sizes, do not allow for an unambiguous comparison of the presented scales; however, all of these studies found good measures of reliability, specificity and sensitivity.

CONCLUSIONS

NeP tools seem to be beneficial screening instruments that should be utilized by specialists and general practitioners to improve the recognition of "possible" NeP and to determine the epidemiology of this disorder. They have been developed to distinguish perceived pain into neuropathic and non-neuropathic, and, therefore, patients with a mixed pain can still present a diagnostic challenge. Clinical examination and interview play an essential role in the diagnostic process and monitoring, and cannot be neglected.

Efficacy of Dry Needling and Acupuncture in Patients with Fibromyalgia: A Systematic Review and Meta-Analysis

Fibromyalgia (FM) is a syndrome that involves chronic pain, fatigue, sleep disturbance and impaired quality of life and daily functioning. In addition to medical and psychological therapies, other therapies including acupuncture and dry needling aim to reduce pain and disability in patients with FM. The aim of this study was to investigate the efficacy of dry needling and acupuncture in patients with FM regarding pain, function and disability in both the short and the long term. MEDLINE, PubMed, SCOPUS and Web of Science databases were systematically searched for randomized controlled trial studies evaluating efficacy data of dry needling or/and acupuncture treatments to improve pain, fatigue, sleep disturbance and impaired quality of life and/or daily function. A qualitative analysis including the methodological quality and a systematic data synthesis was performed. A total of 25 studies addressed the selection criteria. Most studies had an acceptable methodological quality. Four studies assessed the effect of dry needling, and twenty-one studies assessed the effect of acupuncture. In general, both interventions improved pain, anxiety, depression, fatigue, stiffness, quality of sleep and quality of life. However, both techniques were not compared in any study. Acupuncture and dry needling therapies seems to be effective in patients with FM, since both reduced pain pressure thresholds, anxiety, depression, fatigue, sleep disturbances and disability in the short term. It is still required to compare both techniques and their application in the long term.

The Self-Reported Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and PainDETECT Questionnaires in COVID-19 Survivors with Post-COVID Pain

This study aimed to analyze correlations between Self-Report Leeds Assessment of Neuropathic Symptoms (S-LANSS) and PainDETECT with proxies of sensitization, pain-related, or psychological/cognitive variables in coronavirus disease, 2019 (COVID-19) survivors exhibiting post-COVID pain. Demographic, clinical, psychological, cognitive, sensitization-associated symptoms, and health-related quality of life were collected in 146 survivors with post-COVID pain. The PainDETECT and S-LANSS questionnaires were used for assessing neuropathic pain-related symptoms. Patients were assessed with a mean of 18.8 (SD 1.8) months after hospitalization. Both questionnaires were positively associated with pain intensity (p < 0.05), anxiety (PainDETECT p < 0.05; S-LANSS p < 0.01), sensitization-associated symptoms (p < 0.01), catastrophism (p < 0.01), and kinesiophobia (p < 0.01) and negatively associated with quality of life (PainDETECT p < 0.05; S-LANSS p < 0.01). Depressive levels were associated with S-LANSS (p < 0.05) but not with PainDETECT. The stepwise regression analyses revealed that 47.2% of S-LANSS was explained by PainDETECT (44.6%), post-COVID pain symptoms duration (1.7%), and weight (1.1%), whereas 51.2% of PainDETECT was explained by S-LANSS (44.6%), sensitization-associated symptoms (5.4%), and anxiety levels (1.2%). A good convergent association between S-LANSS and PainDETECT was found. Additionally, S-LANSS was associated with symptom duration and weight whereas PainDETECT was associated with sensitization-associated symptoms and anxiety levels, suggesting that the two questionnaires evaluate different aspects of the neuropathic pain spectrum in post-COVID pain patients.