—I do not wish to take an extreme position (even on a point so small), but I disagree on most counts. Separating an ophthalmoplegic-ataxic form of Guillain-Barré syndrome (GBS) from cases with obvious brain-stem signs emphasizes the unusual clinical features produced by peripheral pathology. I have seen scattered perivascular lymphocytes in the brain stem and spinal cord of mundane GBS cases; no doubt this occurs, but no central signs resulted in these cases. Perhaps a fleeting sensory level, Babinski's sign, or unusual neuroophthalmologic finding is explained by these lesions, but this is not brainstem encephalitis. There are also rare patients with inflammatory processes, usually chronic, involving both the brain and peripheral nerves (a patient of mine is described in this issue of the Archives1). The illness described by Bickerstaff2 and Al-Din et al3 is usually distinguishable by clinical signs from the similar Fisher's syndrome produced by GBS.
Ropper AH. Controversy About Fisher's Syndrome-Reply.. Arch Neurol. 1986;43(6):543–544. doi:10.1001/archneur.1986.00520060007004