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.

Association of sensory phenotype with quality of life, functionality, and emotional well-being in patients suffering from neuropathic pain.

Neuropathic pain highly affects quality of life, well-being, and function. It has recently been shown based on cluster analysis studies that most patients with neuropathic pain may be categorized into 1 of 3 sensory phenotypes: sensory loss, mechanical hyperalgesia, and thermal hyperalgesia. If these phenotypes reflect underlying pathophysiological mechanisms, they may be more relevant for patient management than underlying neurological diagnosis or pain intensity.

Cross-cultural adaptation and validation of the Persian version of the painDETECT questionnaire.

Objective: The purpose of this study was to translate and cross-culturally adapt the painDETECT questionnaire into the Persian language and assess the clinometric properties of the translated version (P-PDQ).

Methods: This is a single-center prospective observational study. After forward and backward translations, consensus was achieved by the expert panel on the pre-final version.

Cross-cultural adaptation of the painDETECT questionnaire into Brazilian Portuguese.

Background And Objectives: Neuropathic pain is common in the general population worldwide and Brazil. The painDETECT questionnaire is a notable instrument for screening on neuropathic pain. A Brazilian version of the painDETECT is necessary to broaden the possibilities of identification of neuropathic pain in the Brazilian population for the proper diagnosis and treatment.

Contralateral Sensory and Pain Perception Changes in Patients With Unilateral Neuropathy.

Objective: To test whether contralateral sensory abnormalities in the clinically unaffected area of patients with unilateral neuropathic pain are due to the neuropathy or pain mechanisms.

Methods: We analyzed the contralateral clinically unaffected side of patients with unilateral painful or painless neuropathy (peripheral nerve injury [PNI], postherpetic neuropathy [PHN], radiculopathy) by standardized quantitative sensory testing following a validated protocol. Primary outcome was the independent contribution of the following variables on the contralateral sensory function using generalized linear regression models: pain intensity, disease duration, etiology, body area, and sensory patterns in the most painful area.

Progressive Response to Repeat Application of Capsaicin 179 mg (8% w/w) Cutaneous Patch in Peripheral Neuropathic Pain: Comprehensive New Analysis and Clinical Implications.

Objective: To investigate the efficacy of repeated application of capsaicin 179 mg cutaneous patch in nonresponders to the first application.

Design: Post hoc, as-treated analysis of two prospective trials (STRIDE and PACE) with 52-week follow-up.

Blinding: Open-label.

Pregabalin for neuropathic pain in primary care settings: recommendations for dosing and titration.

Pregabalin is one of the first-line treatments approved for the management of neuropathic pain (NeP). While many patients benefit from treatment with pregabalin, they are often treated with suboptimal doses, possibly due to unfamiliarity around prescribing the drug and/or side effects that can occur with up-titration. This narrative review discusses key aspects of initiating, titrating, and managing patients prescribed pregabalin therapy, and addresses concerns around driving and the potential for abuse, as well as when to seek specialist opinion.

When to consider "mixed pain"? The right questions can make a difference!

The term "mixed pain" is increasingly applied for specific clinical scenarios, such as low back pain, cancer pain and postsurgical pain, in which there "is a complex overlap of the different known pain types (nociceptive, neuropathic, nociplastic) in any combination, acting simultaneously and/or concurrently to cause pain in the same body area." Whether mixed pain is the manifestation of neuropathic and nociceptive mechanisms operating simultaneously or concurrently, or the result of an entirely independent pathophysiological mechanism - distinct from nociceptive, nociplastic and neuropathic pain - is currently unknown. At present, the diagnosis of mixed pain is made based on clinical judgement following detailed history-taking and thorough physical examination, rather than by formal confirmation following explicit screening or diagnostic criteria; this lack of formalized screening or diagnostic tools for mixed pain is problematic for physicians in primary care, who encounter patients with probable mixed pain states in their daily practice.

No pain, still gain (of function): the relation between sensory profiles and the presence or absence of self-reported pain in a large multicenter cohort of patients with neuropathy.

The pathophysiology of pain in neuropathy is complex and may be linked to sensory phenotypes. Quantitative sensory testing, a standardized method to evaluate sensory profiles in response to defined stimuli, assesses functional integrity of small and large nerve fiber afferents and central somatosensory pathways. It has revealed detailed insights into mechanisms of neuropathy, yet it remains unclear if pain directly affects sensory profiles.

Botulinum neurotoxin injections for muscle-based (dystonia and spasticity) and non-muscle-based (neuropathic pain) pain disorders: a meta-analytic study.

Apart from the known efficacy of Botulinum Neurotoxin Type A (BoNT/A) in hyperactive striated and smooth muscles, different pain states have become potential targets of toxin effects. This present study determined the comparative toxin effectiveness in pain reduction among those patients injected with BoNT/A in muscle-based and in non-muscle-based conditions. Randomized controlled trials (RCTs) on the effect of BoNT/A on selected pain conditions were included.

Pain thresholds and intensities of CRPS type I and neuropathic pain in respect to sex.

Background And Aims: Healthy women have generally been found to have increased experimental pain perception and chronic pain has a higher prevalence in female as compared to male patients. However, no study has investigated whether pain intensity and pain perception thresholds are distinct or similar between sexes within various chronic pain entities. We investigated whether average pain intensities and pain thresholds assessed using quantitative sensory testing (QST) differed between women and men suffering from three distinct chronic pain conditions: Complex Regional Pain Syndrome (CRPS type I), peripheral nerve injury (PNI) or polyneuropathy (PNP), as compared to paired healthy volunteers.

The relationship between the reporting of euphoria events and early treatment responses to pregabalin: an exploratory post-hoc analysis.

Background: Euphoria is a complex, multifactorial problem that is reported as an adverse event in clinical trials of analgesics including pregabalin. The relationship between the reporting of euphoria events and pregabalin early treatment responses was examined in this exploratory post-hoc analysis.

Methods: Data were from patients with neuropathic or non-neuropathic chronic pain enrolled in 40 randomized clinical trials, who received pregabalin (75-600 mg/day) or placebo.

Current understanding of the mixed pain concept: a brief narrative review.

Despite having been referenced in the literature for over a decade, the term "mixed pain" has never been formally defined. The strict binary classification of pain as being either purely neuropathic or nociceptive once left a good proportion of patients unclassified; even the recent adoption of "nociplastic pain" in the IASP Terminology leaves out patients who present clinically with a substantial overlap of nociceptive and neuropathic symptoms. For these patients, the term "mixed pain" is increasingly recognized and accepted by clinicians.

Mixed-methods development of a new patient-reported outcome instrument for chronic low back pain: part 2-The Patient Assessment for Low Back Pain-Impacts (PAL-I).

We describe qualitative and quantitative development and preliminary validation of the Patient Assessment for Low Back Pain-Impacts (PAL-I), a patient-reported outcome measure for use in chronic low back pain (cLBP) clinical trials. Concept elicitation and cognitive interviews (qualitative methods) were used to identify and refine symptom concepts. Classical test theory and Rasch measurement theory (quantitative methods) were used to evaluate item-level and scale-level performance of the PAL-I using an iterative approach between qualitative and quantitative methods.

Clinical Manifestation of Acute, Subacute, and Chronic Low Back Pain in Different Age Groups: Low Back Pain in 35,446 Patients.

Background: Low back pain (LBP) is a major healthcare problem causing tremendous economic costs.

Methods: Clinical manifestation of LBP was characterized in 35,446 patients. We focused on the comparison of the acute, subacute, and chronic LBP stage with regard to patients' ages, based on epidemiologic and clinical questionnaires (eg, painDETECT Questionnaire, Pain Disability Index), pain intensity, pain descriptors, and functional impairment.

Mixed-methods development of a new patient-reported outcome instrument for chronic low back pain: part 1-the Patient Assessment for Low Back Pain - Symptoms (PAL-S).

We describe the mixed-methods (qualitative and quantitative) development and preliminary validation of the Patient Assessment for Low Back Pain-Symptoms (PAL-S), a patient-reported outcome measure for use in chronic low back pain (cLBP) clinical trials. Qualitative methods (concept elicitation and cognitive interviews) were used to identify and refine symptom concepts and quantitative methods (classical test theory and Rasch measurement theory) were used to evaluate item- and scale-level performance of the measure using an iterative approach. Patients with cLBP participated in concept elicitation interviews (N = 43), cognitive interviews (N = 38), and interview-based assessment of paper-to-electronic mode equivalence (N = 8).

Sensory symptom profiles differ between trigeminal and thoracolumbar postherpetic neuralgia.

Introduction: Animal experimental evidence suggests that mechanisms of pain generation and response to treatment differ between neuropathic pain in the cephalic and the extracephalic innervation territories.

Objectives: The objective of the study was to examine whether in humans an identical peripheral painful neuropathy is associated with different pain qualities and sensory abnormalities in the face as compared with the thoracic region.

Methods: We retrospectively analysed epidemiological and clinical data of 639 patients with postherpetic neuralgia (PHN) in the face and at the trunk who were collected within a cross-sectional cohort survey and compared the respective sensory symptom profiles captured with the painDETECT questionnaire.

Cebranopadol, a novel first-in-class analgesic drug candidate: first experience in patients with chronic low back pain in a randomized clinical trial.

Chronic low back pain (LBP) is a common condition, usually with the involvement of nociceptive and neuropathic pain components, high economic burden and impact on quality of life. Cebranopadol is a potent, first-in-class drug candidate with a novel mechanistic approach, combining nociceptin/orphanin FQ peptide and opioid peptide receptor agonism. We conducted the first phase II, randomized, double-blind, placebo- and active-controlled trial, evaluating the analgesic efficacy, safety, and tolerability of cebranopadol in patients with moderate-to-severe chronic LBP with and without neuropathic pain component.

Stratifying patients with peripheral neuropathic pain based on sensory profiles: algorithm and sample size recommendations.

In a recent cluster analysis, it has been shown that patients with peripheral neuropathic pain can be grouped into 3 sensory phenotypes based on quantitative sensory testing profiles, which are mainly characterized by either sensory loss, intact sensory function and mild thermal hyperalgesia and/or allodynia, or loss of thermal detection and mild mechanical hyperalgesia and/or allodynia. Here, we present an algorithm for allocation of individual patients to these subgroups. The algorithm is nondeterministic-ie, a patient can be sorted to more than one phenotype-and can separate patients with neuropathic pain from healthy subjects (sensitivity: 78%, specificity: 94%).

Assessment of Patient-Reported Outcome Instruments to Assess Chronic Low Back Pain.

Objective: To identify patient-reported outcome (PRO) instruments that assess chronic low back pain (cLBP) symptoms (specifically pain qualities) and/or impacts for potential use in cLBP clinical trials to demonstrate treatment benefit and support labeling claims.

Design: Literature review of existing PRO measures.

Methods: Publications detailing existing PRO measures for cLBP were identified, reviewed, and summarized.

Peripheral neuropathic pain: a mechanism-related organizing principle based on sensory profiles.

Patients with neuropathic pain are heterogeneous in etiology, pathophysiology, and clinical appearance. They exhibit a variety of pain-related sensory symptoms and signs (sensory profile). Different sensory profiles might indicate different classes of neurobiological mechanisms, and hence subgroups with different sensory profiles might respond differently to treatment.

Pregabalin for the Treatment of Drug and Alcohol Withdrawal Symptoms: A Comprehensive Review.

Treatments for physical dependence and associated withdrawal symptoms following the abrupt discontinuation of prescription drugs (such as opioids and benzodiazepines), nicotine, alcohol, and cannabinoids are available, but there is still a need for new and more effective therapies. This review examines evidence supporting the potential use of pregabalin, an α2δ voltage-gated calcium channel subunit ligand, for the treatment of physical dependence and associated withdrawal symptoms. A literature search of the MEDLINE and Cochrane Library databases up to and including 11 December 2015 was conducted.