A 10-year-old boy presents with multiple daily 5-10 second staring spells accompanied by eyelid fluttering and lip smacking, without postictal confusion. Vital signs are normal; neurologic exam reveals no focal deficits. EEG shows characteristic 3-Hz spike-and-wave discharges. He is started on ethosuximide. Which of the following best describes the mechanism of action of this drug in suppressing abnormal thalamic oscillatory activity responsible for his seizures?
- A)Presynaptic P Q type voltage gated calcium channel antibodies
- B)Ethosuximide blocks thalamic T type calcium channelsGABARITO
- C)Diazepam followed by fosphenytoin for status epilepticus
- D)Carbamazepine use for focal seizures
- E)Postsynaptic nicotinic acetylcholine receptor antibodies
Explicação
The drug described is ethosuximide, which is first line therapy for absence seizures. It works by blocking T type calcium channels in thalamic neurons, thereby reducing the synchronized thalamocortical activity that produces 3 Hz spike and wave discharges. Ver explicação completa e trilha adaptativa →