Few studies have directly compared the clinical features of neuropathic and non-neuropathic pains. For this purpose, the French Neuropathic Pain Group developed a clinician-administered questionnaire named DN4 consisting of both sensory descriptors and signs related to bedside sensory examination. This questionnaire was used in a prospective study of 160 patients presenting with pain associated with a definite neurological or somatic lesion. The most common aetiologies of nervous lesions (n=89) were traumatic nerve injury, post herpetic neuralgia and post stroke pain. Non-neurological lesions (n=71) were represented by osteoarthritis, inflammatory arthropathies and mechanical low back pain. Each patient was seen independently by two experts in order to confirm the diagnosis of neuropathic or non-neuropathic pain. The prevalence of pain descriptors and sensory dysfunctions were systematically compared in the two groups of patients. The analysis of the psychometric properties of the DN4 questionnaire included: face validity, inter-rater reliability, factor analysis and logistic regression to identify the discriminant properties of items or combinations of items for the diagnosis of neuropathic pain. We found that a relatively small number of items are sufficient to discriminate neuropathic pain. The 10-item questionnaire developed in the present study constitutes a new diagnostic instrument, which might be helpful both in clinical research and daily practice.

This large national population-based study indicates that a significant proportion of chronic pain patients report neuropathic characteristics. We identified distinctive sociodemographic profile and clinical features indicating that chronic pain with neuropathic characteristics is a specific health problem.

This study describes the development and validation of the Neuropathic Pain Symptom Inventory (NPSI), a new self-questionnaire specifically designed to evaluate the different symptoms of neuropathic pain. Following a development phase and a pilot study, we generated a list of descriptors reflecting spontaneous ongoing or paroxysmal pain, evoked pain (i.e. mechanical and thermal allodynia/hyperalgesia) and dysesthesia/paresthesia. Each of these items was quantified on a (0-10) numerical scale. The validation procedure was performed in 176 consecutive patients with neuropathic pain of peripheral (n = 120) or central (n = 56) origin, recruited in five pain centers in France and Belgium. It included: (i) assessment of the test-retest reliability of each item, (ii) determination of the factorial structure of the questionnaire and analysis of convergent and divergent validities (i.e. construct validity), and (iii) evaluation of the ability of the NPSI to detect the effects of treatment (i.e. sensitivity to change). The final version of the NPSI includes 10 descriptors (plus two temporal items) that allow discrimination and quantification of five distinct clinically relevant dimensions of neuropathic pain syndromes and that are sensitive to treatment. The psychometric properties of the NPSI suggest that it might be used to characterize subgroups of neuropathic pain patients and verify whether they respond differentially to various pharmacological agents or other therapeutic interventions.

Background Calcitonin gene-related peptide plays an important role in migraine pathophysiology. Erenumab, a human monoclonal antibody that inhibits the calcitonin gene-related peptide receptor, is being evaluated for migraine prevention. Methods In this randomized, double-blind, placebo-controlled, phase 3 study, 577 adults with episodic migraine were randomized to placebo or 70 mg erenumab; 570 patients were included in efficacy analyses. Primary endpoint was change in monthly migraine days. Secondary endpoints were ≥50% reduction in monthly migraine days, change in acute migraine-specific medication treatment days, and ≥5-point reduction in Physical Impairment and Impact on Everyday Activities domain scores measured by the Migraine Physical Function Impact Diary. All endpoints assessed change from baseline at month 3. Results Patients receiving erenumab experienced -2.9 days change in monthly migraine days, compared with -1.8 days for placebo, least-squares mean (95% CI) treatment difference of -1.0 (-1.6, -0.5) ( p < 0.001). A ≥ 50% reduction in monthly migraine days was achieved by 39.7% (erenumab) and 29.5% (placebo) of patients (OR:1.59 (95% CI: 1.12, 2.27) ( p = 0.010). Migraine-specific medication treatment days were reduced by -1.2 (erenumab) and -0.6 (placebo) days, a treatment difference of -0.6 (-1.0, -0.2) ( p = 0.002). The ≥5-point reduction rates in Migraine Physical Function Impact Diary - Physical Impairment were 33.0% and 27.1% (OR:1.33 (0.92, 1.90) ( p = 0.13) and in Migraine Physical Function Impact Diary - Everyday Activities were 40.4% and 35.8% (OR:1.22 (0.87, 1.71) ( p = 0.26). Safety and adverse event profiles of erenumab were similar to placebo. Most frequent adverse events were upper respiratory tract infection, injection site pain, and nasopharyngitis. Conclusions As a preventive treatment of episodic migraine, erenumab at a dosage of 70 mg monthly significantly reduced migraine frequency and acute migraine-specific medication use. (Funded by Amgen). Trial registration ClinicalTrials.gov, NCT02483585.

Headache disorders are prominent health-related drivers of immense economic losses for the EU. This has immediate implications for healthcare policy. Health care for headache can be both improved and cost saving.