Visceral symptoms in patients with anterior cutaneous nerve entrapment syndrome (ACNES): expression of viscerosomatic reflexes?

Purpose: Anterior cutaneous nerve entrapment (ACNES) is characterized by neuropathic pain in a predictable, circumscript abdominal area. The diagnostic delay is long, with half of ACNES-affected individuals reporting nausea, bloating, or loss of appetite mimicking visceral disease. The aim of this study was to describe these phenomena and to determine whether treatment could successfully reverse the visceral symptoms.

Methods: This prospective observational study was conducted between July 2017 and December 2020 at SolviMáx, Center of Excellence for Chronic Abdominal Wall and Groin Pain, Máxima Medical Center, Eindhoven. Adult patients who fulfilled published criteria for ACNES and reported at least one visceral symptom at intake were eligible for the study. A self-developed Visceral Complaints ACNES Score (VICAS) questionnaire that scores several visceral symptoms (minimum 1 point, maximum 9 points) was completed before and after therapy. The success of treatment was defined as at least 50% reduction in pain.

Results: Data from 100 selected patients (86 females) aged 39 ± 5 years were available for analysis. Frequently reported symptoms were abdominal bloating (78%), nausea (66%) and altered defecation (50%). Successful treatment significantly reduced the number of visceral symptoms, with a VICAS before of 3 (range 1-8) and after of 1 (range 0-6) (p < 0.001). A low baseline VICAS was associated with successful treatment outcome (OR 0.738, 95% CI 0.546-0.999).

Conclusion: Patients with ACNES may report a variety of visceral symptoms. Successful treatment substantially reduces these visceral symptoms in selected patients.