Central Sensitisation in Nociceptive and Neuropathic Pain (ALGOS)
The Experience of Nociceptive and Neuropathic Pain: Differences in Levels of Central Sensitization
This study aims to investigate differences in central sensitization among patients with chronic nociceptive pain, neuropathic pain, and mixed pain conditions. Chronic pain is a complex and multidimensional phenomenon involving sensory, cognitive, emotional, and behavioral components, often sustained by mechanisms of central sensitization that contribute to pain persistence and treatment resistance.
Using a multidimensional assessment approach, the study integrates self-report questionnaires, neuropsychological evaluation, psychological measures, treatment adherence assessment, and neurophysiological investigation through laser-evoked potentials (LEP). Participants will be evaluated at baseline and after 12 months to explore differences between pain types and longitudinal changes in central sensitization, cognitive functioning, emotional status, and engagement with treatment.
The findings are expected to improve the understanding of neurobiological and psychosocial mechanisms underlying different chronic pain phenotypes and to support more personalized and effective pain management strategies.
Study Overview
Status
Intervention / Treatment
Detailed Description
This is an observational, prospective, longitudinal cohort study designed to examine central sensitization and its multidimensional correlates in patients with chronic pain. The study will be conducted at the IRCCS Centro Neurolesi "Bonino-Pulejo", P.O. "Piemonte", Messina, Italy.
The study population consists of adult patients (18-90 years) suffering from chronic pain and referred to the pain outpatient clinic or hospitalized in pain therapy units. Based on standardized screening instruments for pain classification (Douleur Neuropathique en 4 Questions - DN4 and PainDETECT Questionnaire - PD-Q), participants will be stratified into three cohorts: nociceptive pain, neuropathic pain, and mixed pain. The mixed group includes patients with overlapping nociceptive and neuropathic features or pain conditions that are not clearly classifiable within a single category, including nociplastic pain mechanisms.
All participants will undergo a comprehensive evaluation at baseline (T0) and at 12-month follow-up (T1). The assessment protocol includes measures of pain intensity and central sensitization (Numeric Pain Rating Scale, Central Sensitization Inventory), neurophysiological assessment of nociceptive pathways using laser-evoked potentials (LEP), cognitive screening (Montreal Cognitive Assessment), psychological status (Beck Depression Inventory and State-Trait Anxiety Inventory), pain-related self-efficacy (Pain Self-Efficacy Questionnaire), treatment engagement (Patient Health Engagement Scale), and medication adherence (Morisky Medication Adherence Scale).
Participants will also be stratified according to their pharmacological treatment at baseline, including non-steroidal anti-inflammatory drugs, paracetamol, opioids, cannabinoids, anticonvulsants/gabapentinoids, antidepressants, topical agents, and combination therapies. Changes in treatment during the follow-up period will be documented.
The primary objective is to compare levels of central sensitization among nociceptive, neuropathic, and mixed pain groups using both subjective (CSI) and objective (LEP) measures. Secondary objectives include the characterization of cognitive, psychological, and behavioral profiles associated with each pain type and the evaluation of longitudinal changes over time.
This multidimensional and longitudinal approach aims to clarify the role of central sensitization across different chronic pain phenotypes and to support more tailored and integrated therapeutic strategies.
Study Type
Enrollment (Estimated)
Contacts and Locations
Study Locations
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Sicily
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Messina, Sicily, Italy, 98066
- Irccs Centro Neurolesi Bonino Pulejo
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
- Adult
- Older Adult
Accepts Healthy Volunteers
Sampling Method
Study Population
The sample size was estimated using G*Power 3.1 based on the primary outcome measure, the Central Sensitization Inventory (CSI). A one-way ANOVA (omnibus test) comparing three groups (nociceptive pain, neuropathic pain, and mixed pain) with equal allocation (1:1:1) was assumed. The calculation was performed using a moderate effect size (f = 0.25), a two-sided significance level of α = 0.05, and a statistical power of 0.80.
Based on these parameters, a minimum sample size of 159 participants was required (53 participants per group). Considering an expected dropout rate of approximately 15% over the 12-month follow-up period, the target enrollment was increased to approximately 185 participants, corresponding to about 62 participants per group.
Description
Inclusion Criteria:
- Age between 18 and 90 years
- Presence of chronic pain
- Diagnosis of nociceptive pain, neuropathic pain, mixed pain, or nociplastic pain
- Patients referring to the pain outpatient clinic
- Patients hospitalized in pain therapy units
- Ability to understand the study procedures and provide written informed consent
Exclusion Criteria:
- Presence of severe psychiatric disorders
- Presence of severe neurological disorders
- Presence of oncological diseases in terminal stage
Study Plan
How is the study designed?
Design Details
Cohorts and Interventions
Group / Cohort |
Intervention / Treatment |
|---|---|
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Nociceptive pain
Patients suffering from nociceptive pain
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Neuropsychological assessment Standardized and ad hoc test battery for comprehensive neuropsychological assessment
Laser evoked potentials
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Mixed pain
Patients suffering from mixed pain
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Neuropsychological assessment Standardized and ad hoc test battery for comprehensive neuropsychological assessment
Laser evoked potentials
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Neuropathic pain
Patients suffering from neuropathic pain
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Neuropsychological assessment Standardized and ad hoc test battery for comprehensive neuropsychological assessment
Laser evoked potentials
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What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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neuropsychological assessment
Time Frame: 24 months
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Central Sensitization Inventory (CSI)
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24 months
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Neuropsychological assessment
Time Frame: 24 months
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Cognitive functions: Montreal Cognitive Assessment (MoCA)
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24 months
|
Collaborators and Investigators
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
- Pain
- Neurologic Manifestations
- Nervous System Diseases
- Neuromuscular Diseases
- Peripheral Nervous System Diseases
- Pathological Conditions, Signs and Symptoms
- Signs and Symptoms
- Chronic Pain
- Neuralgia
- Nociceptive Pain
- Musculoskeletal and Neural Physiological Phenomena
- Physiological Phenomena
- Behavioral Disciplines and Activities
- Psychological Tests
- Evoked Potentials
- Cortical Excitability
- Electrophysiological Phenomena
- Nervous System Physiological Phenomena
- Evoked Potentials, Somatosensory
- Neuropsychological Tests
- Laser-Evoked Potentials
Other Study ID Numbers
- CEL/U138/25
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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