Attention-Deficit/Hyperactivity Disorder

300px

Special Topics

ADHD and Epilepsy

• Prevalence of epilepsy in children is about 0.05%; these children are more likely to have ADHD than their peers without seizures. This is particularly relevant in children with absence seizures, in whom pharmacologic seizure control may not adequately restore attention.

• Differentiating the symtpoms is important in children with comorbid epilepsy and ADHD, as well as in children with staring episodes (partial complex or absence seizures); the inattention of ADHD will generally respond to touch and redirection, and children do not experience postictal drowsiness. EEG is sometimes necessary for diagnosis.

• Further, children with ADHD are more likely to have subclinical/epileptiform EEG findings as compared to general population. While they are not considered to have seizures/epilepsy, periods of epileptiform changes are often associated with transient impairment of attention and cognition.

• Antiepileptics and ADHD - Children with epilepsy may experience a sudden improvement in learning, attention, social, and behavior domains when their seizures are treated. This was termed the release phenomenon; it is unclear if this effect is due to seizure control or a separate effect of an antiepileptic. However, phenobarbital and topiramate may cause deterioration in attention and behavior.

• ADHD Treatments and Seizures - It is unclear if stimulants lower seizure threshold; the concern is greater with methylphenidate stimulants. However, in children with epilepsy seizures frequency is not increased when methyphenidate is introduced. Bupropion had been found to cause an increase in seizure ferquency in a dose dependent fashion (SR preparation is safer as it results in lower serum levels). (1)

Further Reading

(1) Schubert R. Attention Deficit Disorder and Epilepsy. Pediatric Neurology 2005;32:1-10.