Dr Andrew Church
The first clue was that many of the patients had had a sore throat before they were struck down with the illness.
So the two doctors started looking for evidence of bacterial infection - and particularly streptococcus bacteria which is a common cause of sore throats.
"It was amazing really and very exciting, when the first results came back," said Dr Church.
"We got first one, then two, then ten...then all the patients had the same result. So we realised we must be onto something."
They had discovered evidence of a rare form of streptococcus bacteria in all their patients.
The bacteria that can cause a simple sore throat had mutated into a much more severe form and triggered the attacks of encaphilitis lethargica.