Ultramicronized Palmitoylethanolamide in the Management of Neuropathic Pain Related to Chronic Inflammatory Demyelinating Polyneuropathy: A Proof-of-Concept Study

Abstract

Background/Objectives: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare autoimmune disease. Neuropathic pain (NP), related to peripheral inflammation, is among its earliest manifestations. This preliminary open-label investigation aimed to evaluate the efficacy of ultramicronized Palmitoylethanolamide (umPEA) in the management of NP. Methods: A total of 14 patients with CIDP, already undergoing immunoglobulin (Ig) therapy, were divided into two groups: Group A received umPEA 600 mg twice daily in addition to Ig for 60 days, followed by Ig alone until the end of the observation (180 days); Group B received Ig alone for 120 days and subsequently umPEA + Ig in the last 60 days of the study. Painful symptom intensity and quality of life were assessed by the Numeric Rating Scale, Neuropathic Pain Symptoms Inventory, and Five Dimensions Health Questionnaire. The safety umPEA profile was evaluated. Results: UmPEA in addition to immunoglobulins allowed for a significant improvement over time in all NP symptoms intensity (p = 0.0007) and in patients' quality of life (p = 0.0036). Conclusions: This study suggests umPEA as a safe and effective treatment in addition to immunoglobulins to improve NP, ameliorating the patient's health status. These results highlight the importance of neuroinflammation modulation in the management of CIDP's painful symptoms, drawing attention to umPEA's potential use also in neuropathies of different etiologies.

Keywords: autoimmune disease; chronic inflammatory demyelinating polyneuropathy; immunoglobulins; neuropathic pain; ultramicronized palmitoylethanolamide.

Figure 1

Treatment scheme and evaluation time points.

Figure 2

Pain intensity over time in Group A (a) and Group B (b); ── umPEA + Ig; ── Ig. NRS: Numeric Rating Scale; S.E.: Standard Error; T: Time point (days).

Figure 3

NPSI score over time in Group A (a) and Group B (b); ── umPEA + Ig; ── Ig. NPSI: Neuropathic Pain Symptoms Inventory; S.E.: Standard Error; T: Time point (days).

Figure 4

EQ5D Index over time in Group A (a) and Group B (b); ── umPEA + Ig; ── Ig. EQ5D: Five-dimension health questionnaire for quality of life; S.E.: Standard Error; T: Time point (days).