False-positive serum botulism bioassay in Miller-Fisher Syndrome
Zeylikman Y, Shah V, Shah U, Mirsen TR, Campellone JV. False-Positive Serum Botulism Bioassay in Miller-Fisher Syndrome. J Clin Neuromuscul Dis. 2015;17(1):27-9.
We describe a patient with acute progressive weakness and areflexia. Both botulism and Miller-Fisher variant of Guillain-Barré syndrome were initial diagnostic considerations, and she was treated with intravenous immunoglobulin and botulinum antitoxin. A mouse bioassay was positive for botulinum toxin A, although her clinical course, electrodiagnostic studies, and cerebrospinal fluid findings supported Miller-Fisher syndrome. This patient's atypical features offer points of discussion regarding the evaluation of patients with acute neuromuscular weakness and emphasize the limitations of the botulism bioassay.