Clinical record
A 61‐year‐old man with moderate stroke risk factors, including hypertension and hyperlipidaemia, presented with rapidly progressive ptosis, diplopia, ataxia and dysarthria. No infective prodrome or suspected food poisoning was initially disclosed. Given this presentation, brainstem stroke was the primary differential diagnosis.
On Day 2, he developed vomiting, dysphagia and severe respiratory distress, requiring intubation. He subsequently developed complete ophthalmoplegia, descending flaccid paralysis and required ventilation. A differential diagnosis of Miller Fisher syndrome was then considered. Sequential intravenous immunoglobulin and plasma exchanges were minimally effective. Cerebrospinal fluid analysis was unremarkable with no raised protein levels. Test results for anti‐ganglioside antibodies, including anti‐GQ1‐b (both IgG and IgM), were negative. Nerve conduction studies and electromyogram (performed on Day 4) results confirmed a generalised, predominantly motor neuropathy (Box 1 and Box 2). Results from the magnetic resonance imaging (MRI) scan of the brain and spine/plexus with contrast were normal.
Box 1
Day 4 results from the nerve conduction study and electromyogram suggesting a severe motor predominant neuropathy with relative sensory sparing (likely too early to appreciate muscle denervation)
Box 2
Day 88 results from the nerve conduction study and electromyogram showing persisting generalised reduction in upper and lower limb motor amplitudes, (although improving), with relative sparing of sensory responses
Further history on Day 15 revealed that the patient had consumed foul‐tasting almond milk 12–36 hours prior to symptom onset. The differentials then expanded to include botulism. Following consultation with the infectious diseases department, further tests were requested. Clostridium botulinum culture and test results for toxin A‐G nucleic acid were negative on retained milk sample and stool. The results from the C. botulinum direct toxin test using the mouse bioassay (pooled antitoxin A, B and E) demonstrated the presence of botulinum toxin in a retained sample of the milk. The FilmArray BioThreat Panel (BioFire Defense) test on a retained sample of milk detected botulinum toxin A nucleic acid. After guidance from infectious diseases and public health authorities on Day 16, the patient was administered botulin antitoxin obtained from the National Medical Stockpile. The implicated milk product was subsequently recalled.1 The patient was weaned off mechanical ventilation five months after admission to the intensive care unit.
