In children, epilepsy is one of the most prevalent major neurologic disorders, affecting 4 to 10 children per 1,000.1–4 The association between epilepsy and mental retardation (MR) or cerebral palsy (CP) is well recognized. Approximately 15–30% of epilepsy cases in childhood are associated with these conditions. Clinicians caring for children with MR and CP need to be familiar with the diagnosis and management of epilepsy in this population, as it is a frequent and serious comorbidity to these disorders.

These pages will review the epidemiologic features of both MR and CP and discuss the complex interaction with epilepsy. This discussion will be limited to CP and MR due to antenatal and perinatal etiologies causes that are presumed to be present from birth. Acquired neurologic deficits associated with postnatal insults such as central nervous system infections, hypoxic injury, trauma, and stroke are excluded. These deficits are considered also to be risk factors for epilepsy and, in fact, when associated with MR and CP, may carry an even higher risk of epilepsy development than do MR and CP from antenatal and perinatal etiologies.5 However, the epidemiology and epilepsy risks for these conditions are distinct from those of neurologic handicaps present from birth.

Epilepsy, MR, and CP are manifestations of structural or functional central nervous system disorders. The risk of epilepsy in children with MR or CP is substantially higher than that seen in the general population and is related to the number of disabilities and their severity. The risk remains elevated at least through the first 20 years of life.

Among individuals with MR or CP, epilepsy is characterized by:

More studies are necessary to clarify questions about the association between epilepsy, MR, and CP:

  • Does epilepsy merely reflect an increased severity of the two disabilities, or is epilepsy in the context of MR and CP a manifestation of additional risk factors?
  • What is the contribution of epilepsy to adverse outcomes, including mortality, in this population?
  • What is the role of genetic susceptibility, which appears to be important in all three conditions? How does it interact with other factors?

Adapted from: D'Amelio M, Shinnar S, and Hauser WA. Epilepsy in children with mental retardation and cerebral palsy. In: Devinsky O and Westbrook LE, eds. Epilepsy and Developmental Disabilities. Boston: Butterworth-Heinemann; 2001;3–16. 
With permission from Elsevier (www.elsevier.com). 

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Reviewed By: 
Steven C. Schachter, MD
on: 
Saturday, May 1, 2004