Focal epilepsy in India with special reference to lesions showing ring or disc-like enhancement on contrast computed tomography.
In 150 consecutive cases of simple partial epilepsy significant CT abnormalities were found in 68%. The commonest lesion noted was a hypodense lesion on unenhanced scan, with a ring or disc-like enhancement on contrast scan, and surrounding hypodensity. This lesion was seen in 39 cases and was more common in patients below the age of 15 years and in those with shorter duration of fits (less than 6 months). Nineteen of these cases had focal signs, 16 showed focal slow activity on EEG and 17/39 had neither signs nor focal slowing on EEG. Ten cases with a ring or disc enhancing lesion had evidence of tuberculosis elsewhere in the body, three more had a past history of tuberculosis and four others had a history of close contact with a case of tuberculosis. After 3 months of antitubercular treatment, 23 out of 25 patients who were rescanned showed clearing of the lesion. The two who did not were operated upon, and the lesion was shown histologically to be a tuberculoma. Ten other cases have done well, but have not been rescanned. Only one case was not treated with antitubercular therapy. She developed fits, altered consciousness, and meningitis and recovered from this serious illness after starting antitubercular therapy. Though not histologically verified, it seems justified to conclude that in India a ring or disc enhancing lesion is the commonest accompaniment of focal epilepsy, and that at least one third (and probably more) of these lesions are tuberculomas.