Involvement of the central nervous system in the chronic form of Chagas' disease

Apart from the central nervous system parasitic invasion in chagasic immunodeficient patients and strokes due to heart lesions provoked by the disease, the typical neurological syndromes of the chronic phase of Chagas' disease (CD) have not yet been characterized, although involvement of the peripheral nervous system has been well documented. This study aims at investigating whether specific signs of central nervous system impairment might be associated with the disease.

Twenty-seven patients suffering from the chronic form of Chagas' disease (CCD) and an equal number of controls matched for sex, age, educational and socio-cultural background, and coming from the same geographical regions, were studied using neurological examinations, magnetic resonance images, and electroencephalographic frequency analysis.

Nineteen patients were at the stage A of the cardiac form of the disease (without documented structural lesions or heart failure). Dizziness, brisk reflexes, and ankle and knee areflexia were significantly more prevalent in the patients than in the controls. The significant findings in quantitative electroencephalogram were an increase in the theta relative power and a decrease in the theta dominant frequency at temporal-occipital derivations. Subcortical, white matter demyelination was associated with diffuse theta bursts and theta-delta slowing in two patients.

Our findings suggest a discrete and unspecific functional cortical disorder and possible white matter lesions in CD. The focal nervous system abnormalities in CD documented here did not seem to cause significant functional damage or severely alter the patient's quality of life.