Many electroencephalographers have accepted the dictum that with the passage of time brain tumors produce increasing focal EEG abnormality, while cerebrovascular accidents result in diminishing abnormality; to substantiate this, individual cases have been cited, but there has been a dearth of systematic study of this problem. Roseman et al.13,14 wrote on the value of serial EEG's in vascular lesions; Churchill and Gonzales,5 in both tumors and cerebrovascular disease, and Daly and Thomas,7 in supratentorial tumors. The afore-mentioned thesis was subjected to scrutiny in the present research, and significant variations from the accepted rule were encountered.
Method
The records of 42 patients with verified braintumors and 42 with cerebrovascular accidents (either verified or corroborated by sufficiently long clinical observation) who had two or more EEG's were reviewed; these 84 patients had a total of 206 EEG's. The clinical records were checked carefully for the sequence of symptoms and signs