The safety and efficacy of methylphenidate (MPH) in the treatment of ADHD, group 1) with epilepsy and group 2) with EEG abnormalities without seizures, were determined in a study of 119 children (98 males, 21 females; ages 6 to 16 years) at Gazi University, Ankara, Turkey. The neurologic examination showed only soft signs in 8% of patients. Brain scans, vision and hearing were normal, and WISC-R scores were average (mean 92.3 +/- 0.2). Of 57 patients with epilepsy, 34 had complex partial seizures, 13 had tonic-clonic seizures, and 10 had multiple seizures; 52 received antiepileptic (AED) monotherapy and 5 polytherapy. At the end of the 12 month period of AED with added MPH (0.3-1 mg/kg/day) treatment, the mean yearly seizure frequency was unchanged (8.2 pre-MPH treatment and 8.1 post-treatment), but 5 (10%) patients had an increase in seizures. None of the 62 patients with ADHD and EEG abnormalities developed seizures during treatment with MPH (without AED). Percentage of patients with EEG epileptiform activity was decreased in both the ADHD+epilepsy group and the ADHD without seizure group; 35.1% at baseline cf 19.3% post-treatment (p=0.01) and 24.2% cf 12.9% (p=0.02), respectively. The baseline and the last mean total ADHD and Conners’ scores from parents’ and teachers’ questionnaires showed significant improvements in both the epileptic and the abnormal EEG groups. On clinician ratings, 92 of the 119 children in the study showed reduced ADHD symptoms, and only 9 patients had deterioration in behavior, 6 of whom were epileptic. Side effects of MPH were observed in 26 (22%) patients and included loss of appetite (23), sleep disorder (19), stomachache (14), headache (14), and motor tics (2); none required MPH withdrawal. MPH is considered safe and effective in patients with ADHD and epilepsy, when combined with AED treatment, and in patients with ADHD and abnormal EEG without seizures. [1]

COMMENT. The PDR advises against the use of methylphenidate (MPH) in patients with seizures or with abnormal EEG. MPH is thought to lower the convulsive threshold. The present report confirms that of previous authors, and shows that MPH may be a safe and effective treatment for ADHD complicated by epilepsy, provided that seizures are controlled by anticonvulsant medication [2]. MPH should be discontinued or the dosage reduced, if seizures recur despite optimal doses of AED. The present study finds that the likelihood of seizure recurrence is 10% in ADHD patients with treated epilepsy who receive MPH. In ADHD patients with abnormal EEG without clinical seizures, MPH did not appear to cause seizures and may have a normalizing effect on the EEG [3]. The prevalence of abnormal EEG in patients with ADHD is reviewed in Ped Neur Briefs Oct 2000;14:73-74.

Hemmer SA, Pasternak JK, et al found that 15.4% of nonepileptic children with ADHD demonstrated epileptiform abnormalities in the EEG [4]. During treatment with MPH, seizures occurred in 1 of 175 nonepileptic ADHD patients with normal EEG (0.6%), and in 3 of 30 with epileptiform EEGs (10%). Of 12 children with rolandic spikes, 2 (16.7%) developed seizures with MPH. A normal EEG indicates minimal risk of seizures with MPH therapy for ADHD. In contrast, an epileptiform EEG in nonepileptiform children with ADHD predicts a 10-17% risk of occurrence of seizures. The prophylactic value of AED treatment in these ADHD patients must be weighed against the potential adverse effects of AED, especially on cognition. My own present policy is to withhold AED “umbrella” therapy with MPH. Atomoxetine (Strattera), the new nonstimulant treatment for ADHD, may prove advantageous in these cases, but its effect on the EEG remains to be established.