Investigators from Great Ormond Street Hospital, and Institute of Child Health, London, UK, reviewed the case notes of all patients treated with methylphenidate (MPH) for ADHD at an epilepsy center between 1998 and 2005. All patients were taking AED treatment for at least 6 months at time of starting MPH. Of 18 patients identified with refractory epilepsies (14 generalized, 4 focal) and ADHD, 13 were male and 5 female, median age 11.5 years (range 6-18 years). ADHD symptoms improved in 61% of patients following behavioral management and daily MPH 0.3-1 mg/kg/day. Treatment was discontinued because of adverse effects in 3 (18%) patients (dysphoria in 2, anxiety in 1). Seizure control showed no statistical impairment caused by use of MPH; one patient showed an increase in seizure frequency after initiating MPH, and seizure frequency remained elevated after discontinuation of MPH. 
COMMENTARY. MPH may be beneficial in treatment of ADHD and AED refractory epilepsy, without significant impairment of seizure control. Despite benefits of MPH in the majority of comorbid epilepsy/ADHD patients, an exacerbation of seizures occurring in the occasional patient requires caution and moderation in introduction of MPH and continuation of AED therapy in optimal dosage. Of 20 epilepsy/ADHD patients whose seizures were controlled by AEDs, none had attacks while taking MPH . MPH is generally safe in children with comorbid epilepsy/ADHD whose seizures are controlled with AEDs. In contrast, children with ADHD and subclinical epileptiform EEG not treated with AED are at increased risk of seizures with introduction of MPH. The incidence of seizures following MPH was 16.7% in children with ADHD and centro-temporal (rolandic) spikes compared to 0.6% in ADHD patients with normal EEGs .