Hematological Indices and Sympathetic Block Response in Neuropathic Pain

Hematological Inflammatory Indices as Predictors of Treatment Response to Sympathetic Nerve Blocks in Neuropathic Pain: A Prospective Observational Study

This prospective observational study aims to evaluate the relationship between hematological inflammatory indices and clinical treatment response in patients with neuropathic pain undergoing sympathetic nerve block procedures as part of routine clinical care. Hematological parameters including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), aggregate index of systemic inflammation (AISI), and red cell distribution width (RDW) will be evaluated before and after treatment. The association between changes in these indices and pain outcomes will be analyzed.

Neuropathic pain is a complex chronic pain condition involving inflammatory, neural, and immune-mediated mechanisms. Increasing evidence suggests that systemic inflammatory processes may contribute to the pathophysiology and persistence of neuropathic pain. Hematological inflammatory indices derived from routine complete blood count parameters have recently emerged as inexpensive and accessible biomarkers reflecting systemic inflammatory status.

Although several studies have investigated inflammatory markers in chronic pain syndromes, data regarding the relationship between hematological inflammatory indices and treatment response following sympathetic nerve block interventions in neuropathic pain are limited.

This prospective observational study aims to evaluate whether hematological inflammatory indices are associated with treatment outcomes in neuropathic pain patients treated with sympathetic nerve block procedures as part of routine clinical management. Adult patients diagnosed with neuropathic pain and scheduled for sympathetic nerve block treatment will be prospectively followed for 3 months.

Clinical outcomes including Numeric Rating Scale (NRS), DN4 and/or LANSS neuropathic pain scores, Global Perceived Effect (GPE), and analgesic consumption will be recorded. Hematological indices including NLR, PLR, MLR, SII, SIRI, AISI, and RDW will be calculated using routine hemogram parameters.

The study is designed as a non-interventional, single-center, prospective observational clinical study. The treatment approach will not be altered for research purposes.

Inclusion Criteria:

• Age ≥18 years
• Diagnosis of neuropathic pain based on clinical evaluation
• DN4 and/or LANSS scores compatible with neuropathic pain
• Undergoing sympathetic nerve block as part of routine clinical treatment
• Availability of pre-treatment and follow-up hemogram parameters
• Ability to provide written informed consent

Exclusion Criteria:

• Age <18 years
• Active infection or acute inflammatory disease
• Active malignancy
• History of hematological disease
• Immunosuppressive therapy or systemic corticosteroid use
• Major surgery or severe trauma within the last month
• Pregnancy or breastfeeding
• Autoimmune or rheumatologic inflammatory disease
• Missing follow-up data