Saturday, September 21, 2013

Botulism

Botulism is an acute neurologic disorder that causes potentially life-threatening neuroparalysis due to a neurotoxin produced by Clostridium botulinum. The 3 main clinical presentations of botulism are as follows:
·                Infant botulism
·                Foodborne botulism
·                Wound botulism
Essential update: FDA approves first heptavalent botulism antitoxin
On March 22, 2013, the FDA approved the first botulism antitoxin that can neutralize all 7 known botulinum nerve toxin serotypes. The heptavalent antitoxin is derived from horse plasma and is the only drug available for treating botulism patients over 1 year of age, including adults. It is also the only available drug for treating infant botulism that is not caused by nerve toxin type A or B.[1, 2, 3, 4]
Signs and symptoms
More than 90% of patients with botulism have 3-5 of the following signs or symptoms:
·                Nausea
·                Vomiting
·                Dysphagia
·                Diplopia
·                Dilated/fixed pupils
·                Extremely dry mouth unrelieved by drinking fluids
Generally, botulism progresses as follows:
·                Preceding or following the onset of paralysis are nonspecific findings such as nausea, vomiting, abdominal pain, malaise, dizziness, dry mouth, dry throat, and, occasionally, sore throat
·                Cranial nerve paralysis manifests as blurred vision, diplopia, ptosis, extraocular muscle weakness or paresis, fixed/dilated pupils, dysarthria, dysphagia, and/or suppressed gag reflex
·                Additional neurologic manifestations include symmetrical descending paralysis or weakness of motor and autonomic nerves
·                Respiratory muscle weakness may be subtle or progressive, advancing rapidly to respiratory failure
The autonomic nervous system is also involved in botulism, with manifestations that include the following:
·                Paralytic ileus advancing to severe constipation
·                Gastric dilatation
·                Bladder distention advancing to urinary retention
·                Orthostatic hypotension
·                Reduced salivation
·                Reduced lacrimation
Other neurologic findings include the following:

·                Changes in deep tendon reflexes, which may be either intact or diminished
·                Incoordination due to muscle weakness
·                Absence of pathologic reflexes and normal findings on sensory and gait examinations

·                Normal results on mental status examination