Schmidt 2002.

Methods	A retrospective cohort study analysing the EEGs of 124 children and adolescents treated with methylphenidate
Participants	Number of participants screened: not stated Number of participants included: 124 Number of participants followed up: 124 Number of withdrawals: 0 Diagnosis of ADHD: ICD‐10 (subtype: F90.0, predominantly inattentive type (64,5%), F90.1, predominantly hyperactive type (35,5%)) Age: mean 10.3: years old (range 6.1‐17.1) IQ: 4% were intellectually disabled Sex: 113 males, 11 females Methylphenidate‐naïve: both methylphenidate naïve and not methylphenidate naïve participants included in the study Ethnicity: not stated Country: Germany Comorbidity: nocturnal enuresis (4%), mild intellectual disability (4%), mixed disorders of conduct and emotions (3.2%), absence epilepsy (0.8%), focal epilepsy (1.6%), developmental anomaly or developmental delay (0%), no comorbidity (64.5%) Comedication: 94.4% of the sample did not use another type of medicine apart from methylphenidate. 2.4% used anticonvulsant, and 0.8% were treated with different medicines Sociodemographics: not stated Inclusion criteria: Patient at the clinic for children and adolescents psychiatry and psychotherapy, University of Cologne Diagnosis of ADHD according to ICD‐10 criteria EEG‐assessment before and during treatment Exclusion criteria: None stated
Interventions	Methylphenidate type: Ritalin Mean methylphenidate dosage: 0.5‐1.0 mg/kg Administration schedule: not stated Mean duration of intervention: not stated Treatment compliance: not stated
Outcomes	Non‐serious adverse events: EEG (according to the German guidelines) measures by medical staff and under supervision from one of the authors (a doctor). A total of 4 categories were formed to evaluate the EEG: Normal (age appropriate basic activity, no hypersynchronous activity (HSA)), no side difference, no focal localised affection, no general changes) Subnormal (dysrhythmic age appropriate basic activity, no HSA, no focal localised affection, no side difference, individual occurrence of steeper sequences) Abnorm (age appropriate basic activity, no HSA, no site difference, no focal localised affection, occurrence of inconstant amplitude differences, individual occurrence of steeper sequences) Pathological (slowed or increased activity, occurrence of HSA, side difference, focal localised affection, general changes)
Notes	Sample calculation: no Ethics approval: yes Funding/vested interest: no funding Authors' affiliations: no affiliations to pharmaceutical companies stated Key conclusions of the study authors: whether or not methylphenidate medication influences the occurrence of epileptic seizures remains unsettled. Given the data from this study, we would conclude that an EEG during therapy with methylphenidate is not necessary. Before commencing a planned methylphenidate therapy, however, an EEG should be performed. Comments from the review authors: there were several parameters from the EEG assessment in the article. However since we in the review have chosen to analyse it according to EEG changes yes/no we have only used the 4 categories that the authors formed Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: no Supplemental information regarding funding, ethics approval received through personal email correspondence with the authors in December 2013 (Sinzig 2013 [pers comm]). Not able to get separate data on the participants without intellectual disability