Objective      To determine the susceptibility of bilateral synchronous rhythmic slow wave displayed in the active electroencephalography(AEEG) in the secondary epilepsy in patients with intracranial tumors.       Methods      Bilateral synchronous rhythmic slow wave displayed in the AEEG of 255 patients

with intracranial tumors who admitted in our hospital from Jan. 2008 to Jul. 2010 were retrospectively analyzed. These patients were divided into 2 groups

group A (patients with preoperative epileptic seizures) and group B (with no preoperative epileptic seizure). The bilateral synchronous rhythmic slow wave in the AEEG was defined the as variable a

epileptiform discharge was used as a reference object

and epileptiform discharge in the AEEG was defined as variable b. Then both bilateral synchronous rhythmic slow wave and epileptiform discharge in the AEEG was defined as variable a+b. The difference of the 3 variables were analyzed in group A and B

and the relationship of variable a with the secondary epilepsy in patients with intracranial tumor was mainly explored.       Results      The occurrence rate of variable a in patients with intracranial tumor was 56.86% (145/255). Before the operation

the occurrence rate of variable a in Group A was 66.23% (51/77)

while that in Group B was 52.81% (94/178)

with that in the former was significantly higher than that in the later group (

P

<

0.05). And the occurrence rate of variable b in group A and group B were 29.87% (23/77) and 9.55%(17/178) respectively

while that of variable a+b were 66.23% (51/77) and 7.30%(13/178) respectively. Both variable b and variable a+b showed great significance in group A and group B (

P

<

0.05). Further analysis on the difference in the occurrence of seizures between the two variables showed that the occurrence rate of variable a+b was obviously higher than that of variable b in Group A (

P

<

0.05). There were 45 patients having early postoperative epilepsy

and 35 (77.78%) of them recorded to variable a or variable a+b in the AEEG. Consistency analysis showed that the occurrence rate of postoperative bilateral synchronous rhythmic slow wave were in high consistency with that of postoperative epilepsy (

k

=0.600 2).       Conclusion      Bilateral synchronous rhythmic slow wave may increase th

e susceptibility of the secondary epilepsy in patients with intracranial tumors.