In 15 patients with KCNQ2 encephalopathy, seizure freedom was achieved using carbamazepine in 40%, phenytoin in 33%, and topiramate or levetiracetam in 27%.
Observational (n=15)
What is the efficacy of various antiepileptic drugs in achieving seizure freedom in patients with early infantile epileptic encephalopathy due to KCNQ2 mutations?
Sodium channel blockers like carbamazepine and phenytoin should be considered first-line treatments for KCNQ2 encephalopathy to achieve early seizure control and potentially improve neurodevelopmental outcomes.
OBJECTIVES: To describe the antiepileptic drug (AED) treatment of patients with early infantile epileptic encephalopathy due to KCNQ2 mutations during the neonatal phase and the first year of life. METHODS: We identified 15 patients and reviewed the electroclinical, neuroimaging, and AED treatment data. RESULTS: Seizure onset was between 1 and 4 days of age with daily tonic asymmetric, focal and clonic seizures in nine patients and status epilepticus in the remaining six. Electroencephalography (EEG) showed multifocal epileptiform abnormalities in nine patients and a burst-suppression pattern in six. All patients were trialed with adequate daily doses of several AEDs before they reached seizure freedom. Six patients (40%) achieved seizure control within 2 weeks of carbamazepine (CBZ) administration and five (33%) were seizure-free with phenytoin (PHT). The last four patients (27%) were successfully treated with topiramate (TPM) (two patients), levetiracetam (LEV) (one), and a combination of LEV with TPM (one). Most patients reached seizure freedom within the first year of life and remained seizure-free thereafter. Twelve patients had moderate-to-severe developmental delay at follow-up. However, the two patients whose seizures ceased within a few days of onset showed only mild cognitive impairment. SIGNIFICANCE: Our findings suggest that drugs acting on sodium channels including CBZ and PHT should be considered as first-line treatment in patients with KCNQ2 encephalopathy. Voltage-gated sodium and potassium channels co-localize at the neuronal membrane. Therefore, the efficacy of drugs acting as sodium-channel blockers could be linked to their modulating effect on both channels. The type of KCNQ2 mutation might influence AED response as well as developmental outcome. Early recognition of KCNQ2 encephalopathy followed by the most appropriate and effective treatment may be important for reducing the neurodevelopmental impairment associated with this disorder.
Pisano et al. (Thu,) conducted a observational in KCNQ2 encephalopathy (n=15). Antiepileptic drugs (carbamazepine, phenytoin, topiramate, levetiracetam) was evaluated on Seizure freedom. In 15 patients with KCNQ2 encephalopathy, seizure freedom was achieved using carbamazepine in 40%, phenytoin in 33%, and topiramate or levetiracetam in 27%.