CT diagnosis of cerebral cysticercosis.

CT findings of 132 patients with cerebral cysticercosis were analysed. The most common finding was multiple parenchymal punctate calcifications, accounting for 53 per cent; calcifications mostly scattered in both cerebral hemispheres. The second most common finding was enhancing ring(s) or nodule(s) of about 1 cm in diameter with perifocal edema, about 43 per cent. Other findings included thin-walled parenchymal cysts of various sizes from less than 1 cm to 7 cm in diameter, non-enhancing low-density area, intraventricular and cisternal cysts, and hydrocephalus due to obstruction of cerebrospinal fluid pathway by the cyst, arachnoiditis, or ependymitis. About 30 per cent of patients had a combination of these forms of cysticercosis. Seizure disorder was the most common presenting symptom. Praziquantel was used effectively in parenchymal cystic forms but without response in intraventricular and cisternal cysts. In conclusion, CT is considered to be the procedure of choice for the detection of cerebral cysticercosis and the follow-up of patients after medical or surgical treatment. When multiple forms of cysticercosis are present, the diagnosis can usually be made with accuracy. A single finding of non-specific pattern such as enhancing ring or nodule, low-density area, or parenchymal cyst(s) without typical mural nodules, has to be differentiated from other conditions such as tumors and inflammatory process. Clinical correlation and follow-up scan are required in these cases in which the definitive diagnosis cannot be ascertained, and in certain cases, surgical intervention may be necessary.