Which mechanism best describes how valproic acid contributes to seizure control?

• A. Increase the effects of GABA
• B. Increase neuronal excitability
• C. Decrease blood pressure
• D. Increase cortisol

Answer: (A)

Valproic acid helps control seizures mainly by boosting GABA-mediated inhibition in the brain. GABA is the main inhibitory neurotransmitter, so increasing its activity dampens neuronal firing and helps prevent the abnormal, excessive electrical activity that underlies seizures. Valproate raises GABA levels and action by inhibiting enzymes that break down GABA and, to some extent, by promoting its synthesis and receptor effectiveness. This mechanism directly promotes inhibitory effects, making seizures less likely to occur. The other options don’t fit because increasing neuronal excitability would worsen seizures, lowering blood pressure isn’t a seizure-control mechanism, and raising cortisol has no direct anticonvulsant role.