There are number of differentials in this case. They can be broadly distinguished clinically by the history and a thorough examination. In addition, the presence, or lack of; a febrile illness, cranial nerve involvement, sensory changes and an ascending vs descending muscle paralysis can help narrow the diagnosis further.
This patient demonstrated the ‘5D’s of botulism’
(Diplopia, Dysarthria, Dysphagia, Dyspnoea, Descending paralysis).
