Clinical Reasoning: Oculobulbar dysfunction

Abstract

A 45-year-old man presented a few days after an upper respiratory tract infection with complaints of diplopia, dizziness, and difficulty walking that progressed within a few hours to complete ophthalmoplegia and facial diplegia. Brain MRI showed nonspecific T2 hyperintensities prior to transfer to our facility. On arrival, he was alert and oriented to person, place, and time. Pupils were dilated nonreactive and corneal reflexes were absent bilaterally. He had complete ophthalmoplegia, facial diplegia, and areflexia. His strength in the extremities per Medical Research Council (MRC) scale on initial presentation was preserved at 5/5. His clinical status declined rapidly, necessitating intubation for respiratory failure. Routine blood laboratory workup for infections, metabolic derangements including vitamin B 1 , and thyroid function tests were within normal limits. On day 1, CSF testing showed mildly elevated protein of 47 mg/dL with a normal cell count. CSF cultures and herpes simplex virus (HSV) testing were negative. He also had an EMG/nerve conduction study (NCS), repetitive nerve stimulation (RNS), and single fiber EMG on day 1, all of which were within normal limits. Serum acetylcholine receptor antibody testing was obtained on admission, which was negative.Questions for consideration: