Clinical and electroencephalographic data indicative of brain tumours in a seizure population.

One hundred and two patients suffering from seizures, with focal EEG signs (101 cases) and focal seizures but generalized EEG abnormalities (one case) were divided into tumour (twenty-one cases) and non-tumour (eighty-one cases) groups on the basis of contrast radiological studies. Retrospective analysis of various clinical data and EEG abnormalities, determined before the contrast radiological examinations, showed that the following were statistically significantly different between the two groups in favour of a tumoral aetiology for the seizures: age at onset of fits (greater than 20 years), presence of focal neurological signs and increased intracranial pressure, presence of focal unilateral delta waves without accompanying epileptic discharges, beta asymmetry between the cerebral hemispheres and hyperventilation-induced electrical seizures. A brain scan was a very useful screening test for the detection of a tumoral aetiology for seizures.