Ring or disc enhancing lesions in epilepsy in India.
In India a common CT finding in epilepsy is a ring/disc enhancing lesion (RDEL). This lesion is hypodense on plain scan and shows a ring or disc-like enhancement on contrast CT scan. This study reports on 186 cases with such lesions, found in 26.1% of all focal epilepsy. It was commoner in children. Fifty-three per cent of the cases had had fits for less than 3 months, 29.6% had had fits for more than 6 months and 17.6% for more than a year. Focal signs were seen in 20% of cases and focal EEG slowing in 57.1%. The lesion cleared on anticonvulsants alone in 75% of cases. At present this is the preferred method of treatment unless there is coexisting CNS tuberculosis or close family contact with TB or extraneural cysticercosis. Biopsy was done in 16 cases and the two commonest causes were found to be cysticercosis and tuberculosis. A review of 58 biopsies in four centres in India is included. The frequency of this entity is apparently highest in India and even in other countries where cysticercosis is common, the lesion is not reported as frequently.