Well, ADHD is overrepresented in epileptic population up to 33% (vs. 5-9 % in normal population) This figure is even inflated in treatment-resistant epilepsy. Inattentive presentation is far common with male to female ratio of 1:1 (cf. normal population again)
EDs (epileptiform discharges) or seizure activity+ anticognitive actions of anticonvulsants make it worse, unfortunately.
Normally, for these cases, we optimize seizure control. Lamotrigine is one of the best anti-epileptic that is allegedly pro-cognitive.
Once tightly-controlled, studies suggest safety and efficacy of methylphenidate-based stimulants (over AMPH-based) which are commonly deployed in these clinical scenarios with good results.
My upcoming paper in American J Therapeutics would discuss this at length