Axonal damage in Crohn's disease is frequent, but non-specific.

We have attempted to confirm the claim by Dvorak and Silen that 'Crohn's disease is accompanied by a severe and extensive necrosis of gut axons...[which] may serve to differentiate Crohn's disease from other inflammatory conditions'. In this electron microscope study the diagnoses were withheld until the assessment of axonal damage was completed. We assessed the axonal damage in ileostomy biopsies in 13 cases of Crohn's disease, four cases of ulcerative colitis, and two 'controls'. In Crohn's disease we found a mean per cent of abnormal axons of 29.85, in ulcerative colitis of 21.25 per cent, and in the two 'controls' of 12.11 and 10.63 per cent, respectively. The difference between the 13 cases of Crohn's disease and the six cases of non-Crohn's disease is not significant. We found considerable numbers of abnormal, very small axons of uncertain nature but probably related to regeneration following surgery. Including or excluding such axons did not significantly alter the incidence of abnormal axons. We conclude that axonal damage is common in chronic inflammatory bowel disease and is not specifically related to Crohn's disease.