Botulism

Botulism causes descending symmetric paralysis due to impaired neurotransmission at theneuromuscular junction and cholinergic autonomic synapses. It is due to Clostridium Botulinum, a spore forming anaerobic Gram-positive bacillus in the soil, that produces A, B, and C type neurotoxins. There are four clinical types: food borne botulism, wound botulism, and intestinal colonization in infants and in adults.
Routes of infection are ingestion of contaminated canned meats or goods, spore contaminated wound infections, especially in heroin addicts who engage in subcutaenous injections called "skin popping," and GI colonization in infants. In infants, onset is 8-36 hours after eating, in wounds 4-17 days after injury, when toxin binds and irreversibly blocks all postganglionic parasympathetic synapses, and all ganglionic synapses.

The presentation is often external opthalmoplegia and ptosis, coinciding with dilated poorly reactive pupils, paralysis of accomodation, then dysphagia, dysarthria, dysphonia, and symmetric descending paralysis. Patients should be monitored for impending cardiovascular collapse.

BOTULISM IS DIFFERENTIATED FROM MG BY THE PRESENCE OF GASTROINTESTINAL SYMPTOMS, AND IMPAIRMENT OF PUPILLARY RESPONSES AND ACCOMODATION.

Diagnosis is by history and physical examination. Demonstrating toxin in GI contents, food, confirms. Equine trivalent antitoxin is suggested for adults within 24 hours, and infants may receive human immunoglobulin. Patients should be treated in the intensive care unit. Public health officials should be alerted.

Neurology review article linked describes clinical feature of type F in adults. Cases were sporadic, had incubation period of 24 hours about, and required intubation and ventilatory support for several weeks. Type F (compared to type B) were more likley to have respiratory and extremity weakness, limb weakness and absent deep tendon reflexes and require earlier intubation. Usually antitoxin was given within four days. Diagnosis was made by serum (69 %) and stool culture (80%). Misdiagnosis of cardiopulmonary and respiratory disease was common.