Two forms of encephalitis in opportunistic toxoplasmosis.

Two adult patients receiving immunosuppressive therapy experienced toxoplasma cerebritis. In one, the brain findings were typical of this form of the disease in adults, but the clinical features and brain lesions of the other were atypical, and had some resemblance to those seen in congenital toxoplasmosis. It is suggested that two patterns of encephalitis can occur in opportunistic toxoplasma infections, a common form with random foci of gland necrosis associated with numerous intracerebral organisms, and another with vascular lesions and periventricular necrosis. The latter has morphologic features in common with congenital encephalitis, and may also have a similar pathogenesis.