Recurrence of acute colonic pseudo-obstruction in selective adrenergic dysautonomia associated with infectious toxoplasmosis

Background: Acute colonic pseudo-obstruction is a life-threatening condition associated with several pathologic conditions, whose pathophysiology is still uncertain. Case: Autonomic function in a young patient operated on for acute colonic pseudo-obstruction was carefully evaluated; none of the common clinical conditions described in the literature was found to have caused the syndrome. Selective adrenergic failure was suggested by the presence of severe orthostatic hypotension, low basal plasma catecholamine level, and absence of the expected increase on standing and by the findings of provocation tests, cardiovascular tests, and acetylcholine sweat spot test. Biopsy specimens from the colon and small-bowel wall did not show any morphologic or immunohistochemical alteration either in muscle layers or in the autonomic plexus, testifying to the possible occurrence of extrinsic denervation in the presence of an intact plexus. Infectious toxoplasmosis was proved through indirect and direct hemagglutination assays, enzyme-linked immunosorbent assay IgG, IgM, and IgA, immunosorbent agglutination IgM assay, and the protozoa were demonstrated in a biopsy specimen from the rectus abdominis muscle. Conclusions: Selective adrenergic denervation of the gut resulted in recurrent episodes of colonic pseudoobstruction, probably by direct toxicity or a cross-reaction between the immune process and a toxoplasmic antigen, stressing the importance of sympathetic inhibitory modulation on colon motor activity.