Похоже, что в русскоязычной медицинской литературе термин все-таки используют:
http://www.1eeg.ru/view_page.php?page=30
(условно-эпилептиформный феномен) в 3 (33%) случаях...

http://www.spruce.ru/attestation/examples/report_03_3.html
Кроме типичной эпи-активности существуют так называемые условно эпилептиформные феномены, которые расцениваются как признаки снижения порога судорожной готовности.

Однако даже эти авторы "лукавят" (типичная эпи-активность) - поскольку сам термин "эпилептиформный/epileptiform" уже несет в себе информацию (похожий, напоминающий, пр.).
В англоязычных источниках сочетание epileptiform с различными иерминами (условный, неубедительный, пр.) не найдено.

http://rileyanesthesia.org/ftp_folders/staff_folders/green/a...
....epileptiform EEG changes...

http://www.whale.to/vaccine/l/almeida.html
"EEG showed epileptiform tracings" OR "EEG showed abnormalities"

http://www.biomedcentral.com/content/pdf/1471-2202-12-s1-p16...
This study was aimed at investigating
the alteration of different EEG characteristics in
epilepsy contingent upon the treatment.

http://www.sciencedirect.com/science/article/pii/00913057739...
EEG epileptiform activity was observed and initially consisted of transient spike events
http://www.epilepsysociety.org.uk/AboutEpilepsy/Whatisepilep...
Although this all sounds simple, it is not quite so easy! Usually when someone has a seizure, the seizure does not cause a typical pattern on the EEG, it just causes a change in the EEG (although there are some types of epilepsy that have typical EEG patterns associated with them). This means that sometimes the EEG is described as ‘abnormal’ (that is ‘not normal’ brain activity) but does not ‘prove’ that the person has epilepsy.

To complicate this further, some people have ‘abnormal’ EEGs but do not have epilepsy. Also, many people who do have epilepsy will only have ‘abnormal’ activity on the EEG if they have a seizure at the time the test is happening.



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Note added at 1 day11 hrs (2011-10-14 20:46:38 GMT)
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You can add "that look like EEG pattern typical for epilepsy"/similar to these...
It depends on your text - how much clarification it requires.