Here is a pdf file of my paper "The Untold Neurological Disease of Franklin Delano Roosevelt" in the current issue of the well-respected British Journal of Medical Biography.
The editor is a neurologist, Christopher Gardner-Thorpe. I chose to submit this work to JHM because it had previously published Armond Goldman's article on FDR in which he opined that Roosevelt's polio was actually Guillain-Barre Syndrome. That article garnered, and continues to garner, considerable attention. I have seen it referred to in a number of comments surrounding our book.
To address that question:
I had the opportunity to get into the Robert Lovett papers at Harvard, which I, in turn, had sent in toto to the FDRL where they are now available on microfilm. In the file, there is a note from Lovett that reveals that FDR probably had a spinal tap at the outset of his 1921 illness (in fact, there is evidence that FDR later underwent a second spinal tap to donate his serum to other victims of Polio, since it was then believed that the spinal fluid of polios was therapeutic. Such was his dedication to curing the disease).
GBS was described in 1916 and Lovett (as many of FDR's later physicians) being the world's leading expert on Polio would surely have known how to differentiate the two. Unfortunately he died unexpectedly in 1924, leaving FDR to find another guru who eventually turned out to be Dr. McDonald. As I have stated at other times, the world's leading expert on polio in the late 1920's was none other than "Doctor" Franklin Delano Roosevelt, who, had he not chosen to re-enter public life, would have surely spent the remainder of his days at Warm Springs, promoting his rehabilitation center and treating fellow polios- so much for Howard Bruenn's 1970 myth that FDR did not care about his health!
The bottom line here, is that Lovett would surely have known that a spinal tap would unequivocally differentiate between the two diseases (polio has white cells, GBS high protein) and most probably knew the results (as undoubtedly did FDR himself). It can therefore safely be inferred that FDR's 1921 neurological illness was indeed polio.
Despite Goldman's sound academic treatise, based largely on a statistical analysis, he was not privy to the fact of the spinal tap (at least, he didn't cite it in his references). This, aside from the facts that the degree of atrophy, the muscle tenderness at the outset of the disease and the perfect timing for the incubation period between FDR's well known visit to the Boy Scout camp and onset of his illness are all most compatible with polio, all lead to the inevitable conclusion that FDR's 1921 illness was poliomyelitis.