Botulism

Question 1

Botulism is classically characterized by a __ paralysis

Answer 1

Botulism is classically cahracterized by a descending paralysis

Question 2

Botulism in an infant

Answer 2

Clinical suspicion for botulism in an infant should be high as it is life threatening and since incidence is much higher in infants

The syndrome will look like this:

• Diffuse hypotonia in a descending pattern on history
• Autonomic dysfunction with hypotension
• Constipation

Question 3

Spinomuscular atrophy will NOT affect ___

Answer 3

Spinomuscular atrophy will NOT affect the autonomic nervous system

This is a very helpful feature in differentiating it from similar diseases

Question 4

Features of poliomyelitis

Answer 4

• Some reason for being unvaccinated
• Asymmetric myelitis associated with an elevated WBC count on CSF
• Affects primarily the lower motor neurons of the anterior horn

Question 5

Post-polio syndrome

Answer 5

Question 6

Electromyography with repetitive nerve stimulation study

Answer 6

An electrophysiologic test evaluating motor unit action potentials and function at the NMJ

When performed at various vrequencies, helps differentiate presynaptic NMJ disease from postsynaptic NMJ disease (for example, botulism from myasthenia gravis)

Question 7

Why are infants so susceptible to C. botulinum colonization?

Answer 7

In adults, a healthy intestinal flora keeps C. botulinum from growing.

Infants have yet to develop a robust intestinal flora, making them susceptible to colonization. Colonization typically occurs in the cecum.

Question 8

Two most commonly recognized sources of botulinum spores

Answer 8

Honey

Soil contamination of other food (home canned food)

Question 9

Most cases of infantile botulism occur in infants under the age of ___

Answer 9

Most cases of infantile botulism occur in infants under the age of 6 months

Question 10

Do not feed honey to an infant younger than ___

Answer 10

Do not feed honey to an infant younger than 1 year of age

Question 11

Botulism syndrome

Answer 11

• Acute-to-subacute onset over days
• Descending paralysis/hypotonia with hyporeflexia
• Constipation
• Feeding difficulties
• Respiratory difficulties
• Cranial nerve abnormalities (facial weakness, ptosis, occulomotor abnormalities, unresponsive pupils, dysphagia, dysarthria, diminished gag, mydriasis)

Question 12

___ is usually the first symptom of botulism, often preceding other symptoms by several weeks

Answer 12

Constipation is usually the first symptom of botulism, often preceding other symptoms by several weeks

Question 13

Diagnosing botulism

Answer 13

• In an infant
  
  • Fecal specimen with isolation of C. botulinum spores and botulinum toxin
  • Sample size of at least 25-50 g is required for adequate sensitivity
  • These studies take days to come back and should NOT delay treatment
  • EMG findings:
    
    • Decreased aplutide of motor units in at least 2 muscle groups
    • Tetanic and post-tetanic fasciculations
    • Absence of posttetanic exhaustion

Question 14

Treating botulism

Answer 14

• Hospitalization
• Administer anti-toxin as soon as possible
• Mechanical ventilation and nasogastric tube feeding are likely to be required
• DO NOT give antibiotics – they are contraindicated

Question 15

Why are antibiotics contrainidcated in infantile botulism?

Answer 15

Lysis of bacteria by the antibiotics can lead to exacerbation of symptoms due to the release of toxin from dead bacteria

Question 16

Infants with botulism are likely to have gotten it from ___, adults with botulism are likely to have gotten it from ___.

Answer 16

Infants with botulism are likely to have gotten it from honey, adults with botulism are likely to have gotten it from dirt-contaminated food.

Question 17

In the case of an adult with botulism, onset of neurological symptoms is likely to have been preceded by. . .

Answer 17

. . . nausea, vomiting, and diarrhea

Question 18

Diffuse flacid paresthesis in a newborn vs in a 4 month old is likely to be. . .

Answer 18

Newborn: Neonatal myasthenia gravis

4-month-old: Botulism

Question 19

Initial therapy for botulism in children

Answer 19

Less than 1: Human-derived anti-toxin

Older: Horse-derived anti-toxin

This is because horse antitoxin is more likely to cause a hypersensitivity reaction in those under age 1