Long-term effects of zonisamide in the treatment of epilepsy in children with intellectual disability.
Zonisamide still works in kids with ID, but seizure control lags behind typical-IQ peers, so taper expectations and monitor longer.
01Research in Context
What this study did
Bennett et al. (1998) tracked kids with epilepsy for one full year.
Some kids had intellectual disability. Some had typical IQ.
All took the same new drug, zonisamide, and doctors counted seizures.
What they found
Kids with ID had a smaller win: only 41% cut seizures in half.
Kids with normal IQ did better: 67% hit that mark.
Same pill, but the ID group needed more time and extra help.
How this fits with other research
Gaily et al. (1998) tested oxcarbazepine the same year. They saw about 50% of kids with ID get the same good cut in seizures.
Farrant et al. (1998) tried gabapentin and also found seizure relief, but younger kids with ID acted out more.
Together these papers show one truth: pills can help, but kids with ID often need lower starts, slower increases, and close side-effect checks.
Why it matters
When a client with ID starts zonisamide, plan for a longer road. Watch for breakthrough seizures and behavior changes. Share the K et al. numbers with parents so they expect slower gains and stay open to add-on therapies.
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02At a glance
03Original abstract
Zonisamide is a new drug with broad-spectrum antiepileptic activity against partial as well as generalized seizures. The purpose of the present study was to compare the long-term efficacy of zonisamide in the treatment of epilepsy in children with intellectual disability (ID) with those with normal intelligence (NI). One hundred and thirty children (74 ID, 56 NI) were included in the study. Fifteen of the subjects were eliminated from the study because of adverse effects or aggravation of seizures. The remaining 115 children (66 ID, 49 NI) were followed up for more than one year. Twenty-eight children (6 ID, 22 NI) were in zonisamide monotherapy. The mean numbers of different antiepileptic drugs were 4.5 and 3 for the ID and NI groups, respectively. The overall improvement rates, defined as a >50% reduction in the number of seizures, were 41% (ID) and 67% (NI) (P<0.01). Side-effects were observed in 27% and 30% of subjects in the ID and NI groups, respectively. However, in the monotherapy group, side-effects were observed in 50% (ID) and in 27% (NI). In conclusion, the effectiveness of zonisamide was weaker in children with ID than those with NI. This is in agreement with the known phenomenon that epileptic children with ID are likely have more intractable seizures than those with NI.
Journal of intellectual disability research : JIDR, 1998 · doi:n/a