A 2-year-old boy presents to the emergency department with constipation, weak cry, and progressive descending flaccid paralysis. Vital signs show HR 95/min, RR 18/min, BP 95/60 mmHg, temperature 37°C, and SpO2 98% on room air. Parents report he ingested homemade herbal honey syrup 72 hours ago. Ptosis and dilated pupils are noted on examination. Stool culture grows gram-positive rods. The child denies recent diarrheal illness. Which mechanism best explains his neurologic decline?
- A)Autoantibodies against acetylcholine receptors
- B)Autoantibodies against voltage-gated calcium channels
- C)Demyelination of peripheral nerves
- D)Destruction of anterior horn cells by virus
- E)Inhibition of acetylcholine release at the neuromuscular junctionGABARITO
Explicação
Inhibition of acetylcholine release at the neuromuscular junction is the correct answer because botulinum toxin cleaves SNARE proteins and prevents presynaptic ACh release, causing constipation, cranial nerve findings, and descending flaccid paralysis. Ver explicação completa e trilha adaptativa →