2701 Botulism, a mimic of miller fisher syndrome and acute brainstem stroke

Introduction Botulism is a rare neuromuscular junction disorder that causes descending flaccid paralysis, dysautonomia and cranial nerve palsies.¹ Guillain-Barre Syndrome (GBS) is an immune-mediated polyradiculoneuropathy with ascending paralysis, areflexia, dysautonomia and albuminocytological dissociation on cerebrospinal fluid (CSF) analysis.² Miller Fisher variant of GBS causes ophthalmoplegia, areflexia and ataxia.² Brainstem strokes may cause cranial nerve palsies and quadriplegia.³ We present a case of botulism that presented a diagnostic dilemma, confounded by a delayed history of spoiled milk consumption, mimicking GBS and brainstem stroke.

Case A 61-year-old man with moderate stroke risk factors, reported acute diplopia, ataxia and dysarthria. No infective prodrome or suspected food poisoning was initially disclosed.

Day 2, he developed dysphagia and severe respiratory distress requiring intubation. He developed rapidly progressive ophthalmoplegia and descending paralysis, requiring ventilation. Sequential intravenous immunoglobulin and plasma exchanges were minimally effective.

Day 12, his partner recalled consumption of expired almond milk, 2 days before admission. He was provisionally diagnosed with botulism and given botulin antitoxin. He continues to slowly recover.

Clostridium botulinum mouse bioassay was eventually confirmatory. Stool C. difficile antigen and toxins were negative. CSF was bland. Anti-ganglioside antibodies, including GQ1-b were negative. Nerve conduction studies and electromyogram confirmed generalized predominantly motor neuropathy. MRI brain and spine/plexus were normal.

Discussion This case was diagnostically challenging, given limited history at the time and rapidly progressive signs that overlapped between botulism, GBS and brainstem stroke. Tests to distinguish these conditions are not always rapidly available or reliable, so empiric treatment should not be delayed.

References

1. Sobel J. Botulism. Clin Infect Dis. 2005;41(8):1167–73.

2. Dimachkie MM, Barohn RJ. Guillain-Barré syndrome and variants. Neurol Clin. 2013;31(2):491–510.

3. Searls DE, Pazdera L, Korbel E, Vysata O, Caplan LR. Symptoms and signs of posterior circulation ischemia in the new England medical center posterior circulation registry. Arch Neurol. 2012;69(3):346–51.