37 year-old male who, 48 hours after a GI illness, developed fixed, dilated pupils, dysphagia, and bilateral ptosis, with progression to neuromuscular hypercapnic respiratory failure.
Diagnosis: foodborne botulism.
- Botulism toxin blocks Ach release at presynaptic neurons and at the NMJ = motor and endocrine symptoms
- Foodborne botslism presents with:
- GI prodrome à 12-36 hours à sore throat (salivation blocked) and 4 Ds of bulbar palsy (diplopia, dysphagia, dysarthria, dysphonia) à descending paralysis
- No fever, normal vitals, normal mental status
- No sensory deficits, aside from blurry vision (pupillary constrictor paralysis, dry eye (lacrimation blocked), or CNIII involvement).
|Diagnosis||Hallmarks||Why this diagnosis does not fit with the patient’s presentation|
|Myasthenia Gravis||Bulbar palsy, ptosis||Weakness is fatigable.
Treating with an acetycholinesterase inhibitor would have NO EFFECT in botulism (Ach never released).
|Miller-Fisher variant of Guillan Barre||Complete opthalmoplegia, ataxia, areflexia, followed by extremity weakness||Ataxia, +anti-GQ1B antibodies.
IVIG and plasmapheresis will have no effect in botulism.
|Classic Guillan Barre||Ascending weakness after GI illness||Ascending weakness|
|MS||Bulbar palsy, INO||Usually female. Sensory and cerebellar symptoms. Optic neuritis.|
|Organophosphate poisoning||DUMBELS||Acetylcholine excess|