He cannot remember everything he ate during the last 72 hours, but recalls eating lunch at a coffee shop near his office. He and his wife hosted a barbeque one evening at which they served grilled chicken, vegetables, and homemade ice cream. The night before onset of his symptoms, they ate at their favorite Italian restaurant where they shared a calamari appetizer, had salad prepared by the waiter at the table, and shared an entree of Fettuccine Fra Diablo. They finished the meal with a cappuccino and tiramisu. Myasthenia gravis is characterized by muscle fatigue after exercise, and the symptoms fluctuate over time.
Organophosphate toxicity causes a cholinergic syndrome.
It is important that the local or state health department be contacted immediately when botulism is suspected. CSF protein levels are normal in botulism but are almost always elevated in GBS except early in the course of the illness. A CT scan of the head with and without contrast may help rule out a significant cerebrovascular accident or encephalitis. An MRI may be helpful to distinguish soft tissue abnormalities or midbrain lesions. If the history suggests heavy metal or organophosphate toxicity, special tests including evaluation of hair or blood can be done.