A previously healthy 42-year-old man was admitted to the ICU last night with progressive weakness and was intubated early this morning when he became unable to protect his airway. Per his wife, he was in his usual state of health until 2 days ago when he began to complain of weakness, numbness, and pain in his legs. She called an ambulance yesterday when he started having similar symptoms in his arms. On examination he has symmetric weakness in both upper and lower extremities and absence of deep tendon reflexes. CSF studies show a protein level of 110 mg/dL (normal range 15- 45 mg/dL) and a white blood cell count of <5 cells/µL. Further history reveals that the whole family had suffered a diarrheal illness a couple of weeks ago.
What is the most commonly identified infectious precursor to this patient’s syndrome?
A. Giardia lambliaCorrect Answer: B
Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis. Patients generally present with progressive, symmetric ascending weakness of the limbs, often accompanied by paresthesia and pain. On examination, patients will have hypo- or areflexia. GBS may progress to involve the facial nerves and respiratory muscles. CSF studies often reveal albuminocytologic dissociation with an elevated protein level, but normal cell counts. C. jejuni is the most commonly identified infectious disease preceding the development of GBS, occurring in around 30% of cases. CMV is the second most common and Epstein-Barr virus, varicellazoster virus, and Mycoplasma pneumoniae have also been implicated. C. jejuni appears to cause GBS via an autoimmune mechanism involving carbohydrate mimicry between human ganglioside GM1 and C. jejuni lipooligosaccharide. Another late onset complication of C. jejuni is reactive arthritis, also via an immune mechanism.
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