Computed tomography of late-onset epilepsy

ABSTRACT

Epilepsy can be divided into idiopathic epilepsy and symptomatic epilepsy according to the existence ofunderlying organic disease. It has been said that the incidence of the symptomatic epilepsy caused by underlyingorgainic brain disease is higher in late-onset epilepsy after the age of 20 than in childhood-onset epoilepsy. CTis very sensitive and non-invasive method for detection of organic brain disease. 168 cases of late-onset epilepsyafter the age of 20 were studied by CT in recent 2 years were analyzed. The results were as follows; 1. The 3rddecade was the most frequent age group, and the ratio of male to female was 2.5;1. 2. Structural abnormality onbrain CT was demonstrated in 51.8% of hte patient. 3. The older the onset of age was, the higher the rate of theabnormal CT finding, except 5th decade which showed less CT abnormality than 4th decade. 4. The most frequenthistory related to epilepsy was trauma. 63.1% of the patients had no relevant history; and they showed CT findingsof brain tumor, atrophy and infarction in decreasing order of frequency. 5. Abnormal CT finding was demonstratedin 49.2% of normal neurologic examination and in 46.4% of normal EEG study. 6. The most frequent lesion ofabnormal CT scan in late-onset epilepsy was 30 cases(18.4% )of brain atrophy. The next frequent lesion was 18cases (10.7%) of brain tumor. Infarction, parasites and calcification were other frequnet lesions.