Autonomic Nervous System Derangements

Despite these findings, mostly in the cardiac, esophageal and colon tissue 5,14,15, no correlation exists between the intensity of neuronal destruction and dilation of the heart or other microscopic indices of myocarditis in the chronic phase14. Histopathologic foci of damaged nervous tissue are found in a diffuse and irregular distribution. Neuronal parasitism, with periganglionitis and degenerative abnormalities in Schwann cells and nervous fibers being prominent manifestations. Although the cardiac parasympathetic nervous structures seem to be more vulnerable, paravertebral sympathetic ganglia destruction has also been documented4. Autopsy studies in chagasic individuals who were asymptomatic during life and suffered from accidental death show that marked neuronal depopulation may be present in absence of any signs of cardiac disease14,16. Thus, some chagasic patients have marked cardiac autonomic denervation at an early stage in the natural history of the disease.