Effects of zonisamide monotherapy in children with epilepsy.

This study examined the efficacy and safety of zonisamide as monotherapy in pediatric patients with epilepsy. Seventy-seven children with epilepsy (ages 8 months-15 years) were treated with zonisamide. Nine patients were withdrawn early because of side effects; these patients were included in side effect but not efficacy analyses. Zonisamide dosages were initiated at approximately 2 mg/kg per day and adjusted for each patient individually to a maximum of 12 mg/kg per day. Among 44 patients with cryptogenic/symptomatic partial epilepsy, 36 (82%) became seizure free; 4 (9%) had a > or =50% reduction in seizure frequency; and 4 (9%) had no change in seizures with zonisamide treatment. Of 11 patients with cryptogenic/symptomatic generalized epilepsy, 10 (91%) became seizure free, and 1 experienced no change with zonisamide treatment. Similarly, 4 patients (100%) with idiopathic partial epilepsy, and 8 of 9 patients (89%) with idiopathic generalized epilepsy became seizure free with zonisamide treatment; in the last group, 1 experienced no change. Thirty patients (39%) reported side effects, including somnolence (11.7%), decreased spontaneity (7.8%), anorexia (6.5%), and rash (6.5%). Thus, zonisamide is effective for partial seizures with or without secondarily generalized seizures in children and should be considered a broad-spectrum antiepilepsy agent.

Selective mutism and obsessive compulsive disorders associated with zonisamide.

We treated 27 children with idiopathic epilepsy with zonisamide monotherapy over a period of 2 years and observed behaviour disturbances in a prospective study. In all cases, seizure control was excellent; however, two cases (7.4%) had behaviour disturbances. The first (Case 1) was a 14-year-old girl with partial epilepsy which began at age 4 years. Zonisamide was administered at age 6 years, which was effective against her seizures, but selective mutism, violent behaviour, and lack of concentration developed at age 10 years. The second (Case 2) was a 15-year-old girl with generalized tonic-clonic seizures which began at age 10 years. Zonisamide was also effective against her seizures, but obsessive compulsive disorders (OCD) developed at age 13 years. The patients have had no other physical or mental problems and decreasing the dosage of zonisamide reduced the problems. There are few reports of behaviour disturbances provoked by zonisamide monotherapy in epileptic children who are neither physically nor mentally disturbed. While problems can develop several years later, in the present study, decreasing the zonisamide dosage maintained adequate prevention of seizures and eliminated the behaviour disturbances. Zonisamide is still a useful anticonvulsant for epileptic seizures, but physicians should be wary of its adverse behavioural side effects, which may arise several years later.