Five to ten percent of individuals with Down syndrome have a seizure disorder, an incidence that is higher than in the general population. While seizures are no more common in children with Down syndrome than the general population, the incidence of seizure disorders in the Down syndrome population rises substantially beginning at age 20-30, and peaks in the fourth or fifth decade of life.

Tonic-clonic seizures are the most common type in adults with Down syndrome. In most cases, symptoms can be well-controlled with standard anticonvulsant medications. When working with a client who has a seizure disorder, nurses can provide valuable counseling and referrals to minimize the danger if a seizure should occur. It may be safer to choose cross-country skiing rather than downhill skiing, for example, if the individual has significant seizure activity.

Adults with Down syndrome most commonly have partial seizures, staring off briefly into space.