A KCNQ channel opener for experimental neonatal seizures and status epilepticus

YSH Raol, DA Lapides, JG Keating… - Annals of Neurology …, 2009 - Wiley Online Library
YSH Raol, DA Lapides, JG Keating, AR Brooks‐Kayal, EC Cooper
Annals of Neurology: Official Journal of the American Neurological …, 2009Wiley Online Library
Objective Neonatal seizures occur frequently, are often refractory to anticonvulsants, and are
associated with considerable morbidity and mortality. Genetic and electrophysiological
evidence indicates that KCNQ voltage‐gated potassium channels are critical regulators of
neonatal brain excitability. This study tests the hypothesis that selective openers of KCNQ
channels may be effective for treatment of neonatal seizures. Methods We induced seizures
in postnatal day 10 rats with either kainic acid or flurothyl. We measured seizure activity …
Objective
Neonatal seizures occur frequently, are often refractory to anticonvulsants, and are associated with considerable morbidity and mortality. Genetic and electrophysiological evidence indicates that KCNQ voltage‐gated potassium channels are critical regulators of neonatal brain excitability. This study tests the hypothesis that selective openers of KCNQ channels may be effective for treatment of neonatal seizures.
Methods
We induced seizures in postnatal day 10 rats with either kainic acid or flurothyl. We measured seizure activity using quantified behavioral rating and electrocorticography. We compared the efficacy of flupirtine, a selective KCNQ channel opener, with phenobarbital and diazepam, two drugs in current use for neonatal seizures.
Results
Unlike phenobarbital or diazepam, flupirtine prevented animals from experiencing development of status epilepticus when administered before kainate. In the flurothyl model, phenobarbital and diazepam increased latency to seizure onset, but flupirtine completely prevented seizures throughout the experiment. Flupirtine was also effective in arresting electrographic and behavioral seizures when administered after animals had developed continuous kainate‐induced status epilepticus. Flupirtine caused dose‐related sedation and suppressed electroencephalographic activity but did not result in respiratory suppression or result in any mortality.
Interpretation
Flupirtine appears more effective than either of two commonly used antiepileptic drugs, phenobarbital and diazepam, in preventing and suppressing seizures in both the kainic acid and flurothyl models of symptomatic neonatal seizures. KCNQ channel openers merit further study as potential treatments for seizures in infants and children. Ann Neurol 2009;65:326–336
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