A 53-year-old female presents with mydriasis, ptosis, diplopia, dysphagia, dysarthria, and a progressive, symmetric descending flaccid paralysis. She is conscious and has no cardiovascular perturbations. Colleagues at other area hospitals are reporting several similar cases. You recommend to:A. Start plasmapheresis or intravenous immunoglobulin and admit her to an intensive care unit (ICU) for close respiratory and cardiovascular monitoring
Correct Answer: C
Clostridium botulinum produces neurotoxins (types A–G) that block acetylcholine release and affect both nicotinic and muscarinic receptors. Symptoms of botulism include an acute, afebrile, symmetric, descending flaccid paralysis, and prominent bulbar palsies (diplopia, dysarthria, dysphonia, and dysphagia). Blockade of muscarinic receptors result in postural hypotension, nausea, and vomiting from ileus. Respiratory muscle involvement can result in respiratory failure. Mental status is not affected; patients usually have a clear sensorium.
The diagnosis of botulism must be done on a clinical basis as laboratory testing is specialized and requires several days to complete. Differential diagnosis includes Guillain-Barre Syndrome, myasthenia gravis, tick paralysis, organophosphate toxicity, and tick paralysis. Distinguishing features of botulism include prominent cranial nerve palsies initially, symmetric, descending progression, and absence of sensory nerve dysfunction.
Features suggestive of bioterrorism as cause of an outbreak of botulism include a large number of cases, outbreak with an unusual botulinum toxin type, outbreak in a location without a common dietary exposure, and multiple outbreaks at the same time without common source.
Treatment of botulism is largely supportive. Antitoxin should be administered in a timely basis (most effective if given within 24 hours). The antitoxin will limit the severity of disease and subsequent nerve damage but will not reverse existent paralysis.